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Foundations of Relational Realism
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oun  ations o e ationa
ea ism
A Topological Approach to
uantum
Mechanics and the Philosophy o Nature Michael Epperson and Elias Zafiris
Lanhan1
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Library of Congress· Catalogingin...Publication Data Epperson, Michael.
Foundations of relational realism : a topological approach to quantum mechanics and
the philosophy of nature I Michael Epperson and Elias Zafiris.
·
pages em
Includes bibliographical references and index. ISBN 9780739180327 (cloth : alk. paper) 1. Quantum logic. 2. Quantum theory Elias. 1970 II. Title.
ISBN 9780739180334 (electronic)
Philosophy. 3. Philosophy of nature. I. Zafiris,
QCI74.17.M35E67 2013 530.1201
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2013010287
eTW The paper used in this publication meets the minimum requirements of American National Standard for Information Sciences Materials. ANSIJNISO Z39.481992. Printed in the United States of America
Permanence of Paper for Printed Library
For Anna and Kitty, our Wives, to whom we are forever grateful. •
CONTENTS X Ill
Preface Part I:
• • •
Philosophical Foundations of Quantum Relational Realism
Michael Epperson Elementary quantum relational events, logical causality, mereotopological extension, and the internal relation of the local to the global in quantum mechanical predication Chapter 1 Introduction: Relational Realism: A Program in Speculative Philosophy 1.1
Bipolar Dualism: Reducing Contrast to Mutually Exclusive Relata
1
3
5
Bipolar Dualism and the Scientific Method: The Example of Physical and Philosophical Cosmology
10
1.3
The Fallacy of Misplaced Concreteness
13
1.4
Dipolar Duality: Contrasts of Mutually Implicative Relata
22
1.2
Chapter 2: Substance and Logic in Quantum Mechanics 2.1
2.2
29
'Liberating' Science from Boolean Logic: A Sisyphean Adventure
32
Abandoning the Logic of One World for the Logic of Many Worlds: An Unlikely Liberation
39
Vlll
CONTENTS
•••
2.3
Quantum Mechanics and Boolean Logic
43
2.4
Internal Relations in Quantum Mechanics
52
2.5
The Compatibility Condition for Logical Causality in Quantum Mechanics
58
2.6
Inducing the Global from the Local
63
2.7
Decoherence: Causal Relation or Logical Integration?
68
2 .8
EPR and Quantum Nonlocality
71
2.9
Topological Relations vs. Metrical Relations: Quantum Mechanics and Spacetime
80
2.10 Substance in Quantum Mechanics: Relational Realism and the Philosophy of Alfred North Whitehead Chapter 3: Predication in Quantum Mechanics
86
103
3.1
EPR and Decoherence
106
3.2
The Problem of SelfReference in Quantum Systems
110
Quantum. Mechanics and the Theory of Logical Types
116
Relations as Relata: From SetTheoretic Classical Material Objects to CategoryTheoretic Quantum Relational Events
119
Summary
132
3 .3
3.4
3.5
lX •
CONTENTS
Chapter 4: Logical Causality in Quantum Mechanics: A Relational Realist Ontology
139
4.1
Internal Relation and Logical Implication in Quantum Mechanics
140
4.2
The Compatibility Condition Revisited·
148
4.3
The Evolution of Potentiality to Probability
157
4.4
Quantum Events as Dipolar Units of Relation: Their Subjective and Objective Features Are Mutually Implicative
163
4.5
Quantum Mechanics Presupposes Logically Related Actual Occasions
168
4.6
Summary
170
Chapter 5: Integrating Logical Relation and Extensive Relation: Mereotopology and Quantum Mechanics
179
5.1
Mereotopological Notions of Internal Relation and Logical Implication
185
5.2
Mereotopological Extensive Relations
190
5.3
Summary
194 199
Interlude Part
ll:
Mathematical Foundations of Quantum Relational Realism
Elias Zafiris A sheaftheoretic description of internally related quantum event structures in tenns of Boolean covering systems
211
X
CONTENTS
Chapter 6: Notion of Lo cal ization Proces ses
213
6.1 Localization in Physical Theories
2 13
6.2 Localization Schemes
216
6.3 The Conceptual F ramework of Category Theory
220
6.3.1
The Necessity of a Categorical Framework
220
6.3.2
Categorical Principles and Terminology
222
6 .3. 3
Universality and Equivalence
227
6.4
The Methodology of Uniform Fibrations: Variable Set Presheaves
232
6.5
The Localization Role of Topology: Covering Sieves and Sites
233
Chapter 7: Sheaves of Genns: The Topologic al Case
243
7.1
Loc alization over a Topological Space
243
7.2
Unifonn Localization ofObs ervables
244
7.3
Gluing S ections and LocaltoGlobal Compatibility
246
7.4
Contextuality: Germs and Stalks of O bser va bl e Sh eave s
248
7.5
Compl etion and F unctionalization: Display Bundles
252
7.6
Events: From SetTheoretic to S he afTheoretic Semantics
253
Covering Sieves as Representable F unctors
257
7.7
CONTENTS
XI
Chapter 8: Sheaves of B oolean Genus: The Quantum Topological Case
261
8.1
Quantum Logical Event Algebras and Observables
261
8.2
The Topological Significance of Boolean Contexts
266
8 .3
L ogical Internal Relation: Coherent LocaltoGlobal Ontological Formation
267
8 .4
Functor of Boolean Reference Frames
270
8.5
Functorial BooleanQuantum Internal Relation
273
8.6
Quantum Localization: Sheaf of Boolean Reference Frames
277
8.7
Boolean Localization Systems and Boolean Germs
279
8.8
Gluing Isomorphism of Local Boolean Reference Frames
281
Chapter 9: Functorial Entanglement and Logical Classification
287
9. 1
Composite Systems and Entanglement
287
9.2
Functorial Entanglement
295
9.3
Interpretation of Quantum Events
303
9.4
EPR Correlations
307
9.5
Logical Classification of Quantum Events
3 13
9.6
Truth Valuations in Boolean Localization Systems
318
9.7
Boolean Germ Classification of Measurement Events
323
.
XII 
CONTENTS
Chapter 10: Quantum Localization in a Broader Conceptual Perspective
327
10.1
Boolean Covers and Physical Contexts
327
10.2
Partial Congruence and Adjunction
328
10.3
Classical to Quantum: From Groups to Categories
330
10.4
Topological Localization as Genetic Analysis
333
I 0.5
Boolean Localization and Decoherence
334
10.6
SheafTheoretic Quantum Relational Realism
345
Chapter
11:
Recapitulation: A Semantic Bridge Between Process Metaphysics and Quantum Theory via Sheaves
353
11.1
General Conceptual Dimension
353
11.2
Subtleties of Quantum Theory
356
11.3
Localization in the Quantum Domain
360
11.4
Relational Localization via Sheaves
364
11.5
Germs and Extensive Connection
372
11.6
The Road Ahead: Differential Extensive Connection and Dynamics with Applications to Quantum Gravity
Bibliography Index About the Authors
376 389 399 421
PREFACE If there is a central conceptual framework that has reliably borne the weight of modern physics as it ascends into the twentyfirst century, it is the framework of quantum mechanics. Because of its enduring stability in experimental application, physics has today reached heights that not only inspire wonder, but arguably exceed the limits of intuitive vision, if not intuitive comprehension. Indeed, it is the dizzying aspect of the as cent that many physicists and philosophers have taken as quantum theo ry's emblematic mark of achievement; the theoretical fruits of its com plex formalism are, by this inclination, selectively interpreted as nothing less than the scientific discovery of a heretofore concealed and counterin tuitive physical reality a strange new world spanned by the extremes of quantum singularity on one end, and multiverse on the other. For a great many other physicists and philosophers, however, this currently fashionable tendency toward exotic interpretation of the theo retical fonnalism is recognized not as a mark of ascent for the tower of physics, but rather as an indicator of sway one that must be dampened rather than encouraged if practical progress is to continue. Indeed, it is the great irony of modern physics that a foundation so stable and reliable as quantum mechanics has proven so vulnerable to the attractor of exotic interpretation. One reason is that after over a century of development, the key conceptual and interpretive problems remain unsettled, even in the wake of evolutionary improvements in technology and experimental methodology. Among these now infamous and interrelated problems are: [1] the problem of measurement i.e., the dependency of measurement objectivity upon measurement contextual ity; [2] quantum nonlocality. e.g., a nonstandard, nonlocal conditional probability such as P (BjA) (the probability of event B given event A ) when these events are spacelike
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•
separated, such that event A somehow effects a fasterthanlight probabil ity conditionalization of event
B. (It should be emphasized that classical
conditional probabilities are not the same as quantum conditional proba bilities, though they are sufficiently analogous to invoke the simpler, classical notation here); [3] the problem of coherently integrating the notions of discreteness and continuity in fundamental physical theories. 
This is most notoriously exemplified in the problem of integrating 'quantum' and 'classical' physical theories
i.e., 'classical' in the sense of
presupposing a physical continuum, with no quantization paradigm for .
the evaluation of observables. Newtonian mechanics, as well as Einstein's special and general theories of relativity, are both considered clas sical in this sense. In the present volume, we demonstrate how all three of these diffi culties can be properly understood as interrelated aspects of a single problem: The absence in quantum mechanics of a formal means of de picting localglobal relations in an extensive continuum. As mentioned above, while this problem is most popularly instantiated as the incompat ibility of quantum mechanics and the general theory of relativity (an as pect of problem [3] above), we argue that its proper solution lies first in recognizing the centrality of localglobal relations in
all three
of the
aforementioned problems; and second, in recognizing that the overall genesis of difficulty is the presumption of a fundamentally metrical theo� ry of extension grounded in a settheoretic conceptual framework, the latter being incapable of adequately representing the essential logical and algebraic structural features of quantum mechanics. To be sure, the set theoretic framework has proven extremely fruitful for formal physics throughout the twentieth century; but its adequacy as a conceptual foun dation for modem physics is belied not only by the incompatibility of quantum theory and general relativity, but more deeply by the fact that it renders physics vulnerable to paradoxes, singularities, and infinities. In attending to these incoherent structures, physics has two possible routes forward: It can either incorporate them into its models by propos ing their exotic physical instantiation· e.g., the paradoxical violation of the principle of noncontradiction in the form of 'physical superposi
PREFACE
XV
tions' of actual system states in quantum mechanics, or the notion of 'physical singul arities' . in modem cosmology, etc.; or it " can identify and overco"me the root source of these vulnerabilities, rendering them epis temic art:ifacts akin to the multitude of others so explicated throughout .
the history of science. In the present volume, we proceed to chart out a pathway for this lat ter course by first identifying the central deficiency of the conventional metrical, settheoretic notion of extension: That it characterizes objects as fundamental to relations i.e., such that relations presuppose objects but objects do not presuppose relations. Prior to quantum mechanics, this deficiency went mostly unnoticed; but since it is a signature feature of quantum mechanics that it definitively proscribes specifying the exist ence of·objects in abstraction from their relations (viz., system states in abstraction from measurement), the attempt to depict quantum mechani cal extensiveness as ·fundamentally metrical via a settheoretic fonnal ism again, such that objects are more fundamental than relations is, we believe, doomed from the beginning. The solution we propose begins with the following thesis: Quantum mechanics exemplifies the fact that physical extensiveness is fundamen tally topological rather than metrical, with its proper logicomathematical framework being category theoretic rather than set theoretic. By this the sis, extensiveness fundamentally entails not only relations of objects, but also relations of relations; thus fundamental quanta are properly defined as 'units of logicophysical relat ion' rather than merely 'units of physical relata.' Objects are, in this way, always understood as relata, and like wise relations are always understood objectively. Objects and relations, in other words, are coherently defined as mutually implicative. In this unique twopart volume, designed to be comprehensible to both specialists and nonspecialists, we substantiate this thesis by demonstrating that a revised decoherent histories interpretation of quan tum mechanics, structured within a categorytheoretic topological for malism, provides a coherent and consistent conceptual framework by which local quantum events can be globally internally related both caus ally and logically. Further, this framework allows for a quantum mechan
XVI
PREFACE
•
ical description of spatiotemporal extension that is highly compatible philosophically \Vith the mereotopological model proposed by Alfred North Whitehead, refining and enhancing the latter by elevating it from a settheoretic basis to a categorytheoretic one. as
As a philosophical enterprise, we propose this conceptual framework a speculative ontological program that includes a rigorous m athemati
cal fortnalism. This provides a uniquely powerful approach to solving the three critical problems of quantum mechanics discussed above, as well as others, by integrating their solution within a coherent and intuitive onto logical scheme that is both novel and applicable practically to the physi cal sciences. The central thesis of the relational realist speculative philosophical program introduced in this volume is that the classical, conventional
conception of the relationship between [a] 'physical object' as ontologi cal extant, and [b] 'history of facts' as epistemic construct by which physical objects are characterized, must be reversed if quantum mechan ics is to be coherently understood as an ontologically significant theory. That is, the classical conception of a history as essentially contextual and therefore primarily epistemic
a particular story expressing particular
knowledge of fundamental physical objects must be reconceived, such that physical objects are not merely understood by their fundamental his tories, but rather understood as fundamental histories of quantum events. This requires a novel reconceptualization of 'ontologicar and 'contextu al' as mutually implicative features of every quantum event, wherein the latter is understood as the fundamental, concrete constituent by which the natural world is physically and logically describable. This primacy of objective quantum events (alternatively, quantum 'facts') is, in the opinion of the authors, the critical starting point for any attempt to provide a viable ontological interpretation of the standard formal framework of quantum theory. In this framework, quantum events ...
.
are identified as measurement outcomes referent to corresponding physi cal observables. The theory then provides the means of relating these events. In this respect, the conceptual complexity of any ontological in terpretation of quantum theory stems from two factors: [ 1] The actualiza
PREFACE
xvn
••
tion of a measurement outcome event representing the state of a quantum system, though always globally objective, can only be predicted proba bilistically and contextually i.e., relative to a particular local Boolean measurement context of a selected observable (that is, a context wherein measurement outcomes can be expressed as mutually exclusive and ex haustive true I false propositions). It is always via such local Boolean contextuality that the universe, represented by a global state vector, is decomposed into 'system,' 'measuring apparatus,' and 'environmenf' with their respective state vectors. Equally important, the probability valuations can be affirmed only retrodictively, after a measured result (i.e., a novel fact I unique actualization of a potenti al outcome state) has been reg i stered by the corresponding measuring apparatus. (2] The totali ty of events related to the behavior of a quantum system cannot be repre sented within the same local Boolean measurement context due to the property of noncommutativity of quantum observables. These two factors together necessitate a thorough rethinking of our conceptual and mathematical representation of the notion of a physical continuum suited to the quantum domain of discourse. The first factor illustrates the prom inent role that potential relations play in the process of quantum measurement: Quantum mechanics always entails the evolu tion of [a] potential outcome states that cannot be integrated in term s of classical, Boolean logic (e.g., Schrodinger' s Cat is alive and dead) to [b] probable outcome states that can be integrated in tenns of classical, Boolean logic (Schrodinger' s Cat is alive with probability x, or dead with probability y; and since x + y 1, one and only one of these unique out comes must occur). Apart from a local Boolean measurement context, the evolution of potentia to probability cannot ensue; and as we will argue, this evolution is the central engine of quantum mechanics, without which locally contextualized events cannot be integrated into the globally objective, logically consistent histories ubiquitous to experience (empirical or othe1VIise ). The second factor likewise illustrates the contextual significance of =
the empirical requirement of preparation procedures for the evaluation of observables via quantum measurement: The determination, by these pro
XV!ll
PREFACE
•••
initial actual state of the system and measuring apparatus establishes the local contextualization definitive of their final actual state
cedures, of the
terminal of the measurement. This presupposed contextual correlation is typically understood as an instrumental desideratum rather than a philo sophical one
that is, a desideratum satisfied via an ad hoc conceptual
intervention arbitrarily imposed upon the standard formalism (viz., von Neumann's projection postulate). By contrast, we will demonstrate that this instrumental desideratum can instead be interpreted both philosophi cally and logicomathematically as a
necessarily presupposed feature of
quantum mechanics when these contextual correlations are depicted top ologically
viz., a topological localization of quantum observables with
respect to local Boolean contexts. It must be emphasized that the philosophical implications of these two factors cannot easily be separated from their practical implications. This fact has previously been explored extensively by the authors indi,
vidually
Epperson in his work relating the logical, mathematical, and
philosophical features of Alfred North Whitehead's work to the decoher ent histories interpretations of quantum mechanics;1 and Zafiris in his modeling of the topological features of quantum mechanics by way of categorysheaf theory.2 The deep compatibility underlying these efforts has motivated the authors to seek an integrated philosophical and math ematical framework, which we have termed 'relational realism,'3 that advances refined conceptions of internal relation and extensive connec tion in Whitehead's process theory, amenable to a topological re interpretation, and synthesizes these with the framework of category sheaf theoretic Boolean localization systems viewed from a process standpoint. To glimpse the essence of this synthesis, the reader is invited to im agine a conceptual triangle, where on the top node sits quantum theory (founulated in the usual Hilbert space language or in the decoherent his tories language) and on the two bottom nodes sit the philosophical struc ture of Whitehead's process theory on one side, and the mathematical structure of categorysheaf theory on the other. The correlation of the quantum node with the processtheoretic node, as it has been presented
PREFACE
XIX •
by Epperson, finds its conceptual correspondence to the correlation of the quantum node with the categorysheaf theoretic node, as it has been presented by Zafiris a correspondence both in tern1s of tern1inology and interpretation.. Thus, the conceptual triangle commutes as we circulate around it, allowing for not only a detailed correlation of the process theoretic node with the sheaftheoretic node, but one that also preserves the already established correlations between each of these and the quan tum node. The focus of the present volume is the demonstration of the applica bility and ultimate relevance of this synthetic scheme toward a coherent and empirically adequate ontological interpretation of quantum theory, and in this regard, a subtle balance is kept between the philosophical as pects and the corresponding mathematical aspects as these converge. To that end, part I introduces the philosophical foundations of relational re alism as instantiated in quantum mechanics, the latter presented in intro ductory fashion so as to be suitable for nonspecialists in physics or mathematics. Part II, in tum, further elaborates this conceptual frame work in fonr1al mathematical language appropriate for specialists in physics and mathematics, such that philosophical scheme' s technical ap plicability to modern physics can be rigorously demonstrated. Despite this structure, however, each part is properly understood only within the context of the overall synthesis. It is important to note that the construction of this synthesis does not follow a strictly linear course . Instead, it unfolds in such a way so as to show, from a convergence of both philosophical process theoretic and mathematical categorysheaf theoretic views, the adequacy and indeed advantage of the relational realist framework in the development of a coherent ontological interpretation of quantum mechanics one that can be understood as exemplifying, more broadly, a coherent and empirically adequate philosophy of nature. To be sure, the conceptual breadth of both Whitehead's process theo ry and categorical sheaf theory far exceeds their restricted application to quantum theory as explored herein, and we consider this to be advanta geous for our objectives. By employing these rich conceptual philosophi
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PREFACE
c al and m athematical frameworks, taking particular advantage of their systematic coherence, we hope to contribute to the formulation of a real istic ontological interpretation of quantum mechanics that avoids the par adoxes, inconsistencies, and counterintuitiveness typical of many alter native interpretations. This research was supported by the John E. Fetzer Memorial Trust (Grants DIIC36 and D21C62). The authors are grateful to the following for their invaluable advice and discussion, technical critiques, and col laboration: Jan Walleczek, Tim Eastman, Roland Omnes, Stuart Kauff man, David Finkelstein, Anastasios Mallios, Stephen Selesnick, Laszlo Szabo, and Vassilios Karakostas. And thanks especially to our colleague and great friend Karim Bschir, whose insights and contributions to this project have been invaluable. Most of all, we wish to thank Bruce Fetzer and the John E. Fetzer Memorial Trust, without whose sponsorship this work would not have been possible.
Notes See, for example: Michael Epperson, Quantum Mechanics and the Phi losophy of Alfred North Whitehead (New York: Fordham University Press, 2004); Michael Epperson, ''Quantum Mechanics and Relational Realism: Logi cal Causality and Wave Function Collapse," Process Studies 3 8, no. 2 (2009): 34066. 2. See, for example: Elias Zafrris, "Quantum Event Structures from the Perspective of Grothendieck Topoi," Foundations of Physics 34, no. 7 (2004): 1 06390; Elias Zafrr is, "Generalized Topological Covering Systems on Quan tum Events' Structures," Journal of Physics A: Mathematical and General 39, no. 6 (2006). 3 . Relational realism and its topological interpretation of quantum me chanics ought not be confused with the 'relational quantum mechanics' program of Carlo Rovelli. [See, for· example: C. Rovelli, "Relational quantum mechanics," International Journal of Theoretical Physics 35 (1 996): 1 63778.] Many aspects of both programs are sufficiently compatible for fruitful conversation; 1.
,,
'
however the underlying conceptual frameworks and philosophical implications of each are very different.
PART I
Philosophical Foundations of uantum Relational Realism
Elementary quantum relational events, logical causality, mereotopological extension, and the internal relation of the local to the global in quantum mechanical predication
MICHAEL EPPERSON A.M., Ph.D. (University of Chicago)
CHAPTER!
Introduction Relational Realism: A Program in Speculative Philosophy
Speculative Philosophy is the endeavour to frame a coherent, logical, necessary system of general ideas in terrns of which every element of our experience can be interpreted . . . It is the ideal of speculative phi losophy that its fundamental notions shall not seem capable of abstrac tion from each other. In other words, it is presupposed that no entity can be conceived in complete abstraction from the system of the uni verse, and that it is the business of speculative philosophy to exhibit this truth. 1 Alfred North Whitehead
The chief mark of progress in the evolution of a philosophical worldview, whether its foundation be scientific, humanistic, theistic, or some integration of these, is the extent to which it is able to coherently accommodate diverse categories of inquiry without either arbitrary dis pensation or internal contradiction. The precise manner in which a worldview deals with incommensurable categorical principles and the Intern al contradictions and paradoxes often borne of them is of first im•
portance, both to the proper understanding of the particular worldview and its implications, and also to its evaluation in contrast to competing
4
CHAPTER
I
worldviews. Indeed, one could argue that the emblematic feature of any philosophical genre in the history of Western philosophy, if not all phi losophy, is its method of attending to the conceptual incompatibilities within its scope. 2 By that general metric, there have been two dominant approaches by which ·principles incommensurable when treated categorically e.g., ob jectivity and · subjectivity, necessity and contingency, conceptual and physical, infinite and finite, global and local, continuous and quantum, potential and actual have been accommodated in Western thought:
[1]
Their categorization as fundamentally mutually implicative at some deeper level of analysis:
By this method of 'dipolar' relation it is explicitly recognized that the conception of one principle necessarily requires reference to its coun terpart principle. Thus, each relatum constitutive of dipolar conceptual pairs is always contextualized by both the other relatum and the relation as a whole, such that neither the relata (the parts) nor the relation (the whole) can be adequately or meaningfully defined apart from their mutu al reference. It is impossible, therefore, to conceptual ize one principle in a dipolar pair in abstraction from its counterpart principle. Neither prin ciple can be conceived as 'more fundamental than,' or 'wholly derivative of the other. .
Mutually implicative fundamental principles always find their exemplification in both the conceptual and physical features of experience. One cannot, for example, define either positive or negative numbers apart from their mutual implication; nor can one characterize either pole of a magnet without necessary reference to both its counterpart and the two poles in relation i.e., the magnet itself. Without this double refer ence, neither the dejtniendum nor the definiens relati�e to the definition of either pole can adequately signify its meaning; neither pole can be understood in complete abstraction from the other.
INTRODUCTION
[2]
5
Their categorization as fundamentally mutually exclusive at the 'deepest possible' level of analysis:
By this method of 'bipolar ' relation it is implied (often erroneously) that the definition of one principle does not necessarily entail reference to its counterpart principle. Therefore it is possible to conceptualize one principle as fundamental to the other. The Platonic dualism separating conceptual and physical objects is perhaps the preeminent example in Western philosophy. Its l ater rehabilitation in the Cartesian dualism of thought (mind) and extension (matter) is, many would argue, a central feature of the modem Western worldview, given the popular dualistic characterization of mind and brain, or soul and body. Familiar examples of bipolar relation in physics include the classical attempt to characterize basic physical processes as either fundamentally continuou s or quantum, fundamentally wavelike or particulate, etc.
1.1
Bipolar Dua lism : Reducing Contrast to Mutua lly Exclusive Relata
When one considers the long lineage by which one might trace the ideas of the ancient Milesians through the ideas of Pannenides and Hera clitus, and onward through Plato and Aristotle, Descartes and the ration alists and Locke and the empiricists, all the way to Bohr and von Neu mann, it is clear that the relation of contrasting categorical principles as mutually exclusive relata (Method 2 above) has increasingly dominated Western thought over the centuries. This domination has today become especially acute thanks to its conventional projection onto the hypotheti codedu ctive and reductive scientific method. Indeed, despite a variety of schematizations throughout the history of philosophy, the general thesis of mutually exclusive fundamental principles, both ontological and epis temic, has arguably become in the twentyfirst century the defining char acteristic of practically every prevailing scientifically inforrned
CHAPTER
6
1
worldview. One further sees that there have been two general modes by
which mutually exclusive fundamental principles have been brought into relation by this method: [2a]
The qualification of mutually exclusive fundamental principles as
complementary and irreducible characteristics of a more general,
unified, and necessarily transcendent ontology that lies beyond the
scope of rational systematization:
As exemplified by modem science, for example, Bohr's principle of complementarity describes the fundamental physical properties of reality in tenns of conjugate pairs of properties. Epistemically, these pairs are
mutually implicative since they are Fourier transform pairs; thus a more
precise specification of 'particle position' necessarily entails a less pre
cise specification of 'particle momentum.' But ontologically, the matter
becomes more complicated, since the conception and definition of parti cle position does not require reference to the concept of momentum;
whereas the conception and definition of momentum does require refer
ence to the concept of position. As will be seen in the discussion of
Method 2b, below, such incongruities often appear to justify the attempt to assimilate one concept to the other
one aspect of nature to another.
The present case of position and momentum, for example, is an echo of
Pannenides' attempt to assimilate the appearance of change to the fact of
permanence, versus Heraclitus's attempt to assimilate the appearance of permanence to the fact of change. Similarly, positionmomentum com
plementarity finds its reflection in one of the most profound problems in
modem physics
reconciling quantum theory's depiction of nature as
fundamentally discrete, and general relativity's depiction of nature as
fundamentally continuous. Efforts to quantize the continuum via the
quantization of gravity can, in this sense, be seen as an effort to assimi late or reduce the continuous in nature to the discrete.
A cleaner example of complementarity, closely related to that of po
sition and momentum, yet (seemingly) immune to the above difficulty and its solution via assimilation, is waveparticle complementarity,
INTRODUCTION
7
where neither wave nor particle requires direct reference to its counter part for its definition. Each concept is therefore independent of the other and, in ter1ns of its ontological significance, incommensurable in com plementary relation to its counterpart. In answer to these and other ontological difficulties associated with the concept of complementarity, Bohr's solution was to circumvent them altogether by asserting that physical qualifications are essentially epis
temic that is, descriptive of our knowledge of reality rather than reality itself. Any ontological implications of these descriptions therefore lie outside the scope of physics. "In physics," Bohr writes, "our problem consists in the coordination of our experience of the external world . . ." such that "in our description of nature the purpose is not to disclose the real essence of phenomena but only to track down as far as poss ible rela 3 tions between the multifold aspects of our experience." Thus the coherence of this method of reconciling mutually exclusive principles via complementary relation rests upon a similarly sharp sepa ration of epistemology and ontology as mutually exclusive concepts themselves, such that a 'fact of knowledge' no longer implies 'knowledge of a fact' as it does when epistemology and ontology are characterized as mutually implicative. Realism, if it is to remain viable in physics and natural philosophy, is by this method recast as 'transcendent realism, ' implying an inaccessible level of reality where complementary, mutually exclusive principles would ultimately find their proper unifica tion. [2b] The qualification of mutually exclusive categorical principles as higher order characteristics or modes of a deeper, fundamental on tology and epistemology that can be further generalized by the re duction or assimilation of one characteristic to the other. The history of philosophy reveals a clear tendency toward this meth od; indeed, one could argue that its dominance seen especially in the ..
philosophy of nature during the early modern period
was the primary
fuel for its later dominance in modem science and, via the latter, its in
CHAPTER
8
1
creasing popularity in most modern Western worldviews. One can find its origins in 1puch of preSocratic philosophy, perhaps most dramatically in the Eleatic School. As an admonishment against the relation of actuali
ty and potentiality as mutually exclusive, fundamental aspects of reality, for example, Paxmenides gave a convincing argument for the reduction of potentiality
to actuality: Anything that "can be," he asserted, "must
already be." There can be no "coming into being" because anything that comes into being has only two possible derivations: It either came from being, in which case it already exists; or it came from nonbeing nothing
i.e.,
in which case it, too, is nothing, since nothing comes from
nothing. Indeed, for Parmenides, one cannot even imagine a 'potential' actuality that was not already actual in some way, since imagining some thing that did not actually exist would literally amount to imagining 'no thing,' and thinking about nothing, Parmenides argues, is the same as not thinking. Since by this reasoning potentiality is merely a sensoryepistemic ab straction from fundamental actuality, existence is therefore both eternal and unchanging
the Pannenidean 'One'; any perceived differentiation
is thus only apparently real as disclosed via sensation, not actually real as disclosed by reason. Though this laid the groundwork for Platonic ideal ism as another type of philosophical reduction from mutually exclusive fundamental principles extension
ideal I thought I form vs. material/ sensation I
it is important to note that Parmenides was not an idealist,
but rather a monistic materialist. Thus one can find in many modern physical theories a number of Pannenidean reflections: Everett's 'rela tive state' interpretation of quantum mechanics4 (better known as the 'many worlds' interpretation, or MWI, which is an extrapolation of Ev erett's original concept) makes a similar assimilation of potentiality to actuality, such that every possibili ty is understood as an actuality in some particular universe. Further, the di vision of reality into multiple, mutually
exclusive universes is understood by the theory as a higher order abstrac
tion beneath which lies a first order, unified 'multiverse'in many ways akin to the Parmenidean 'One. '
INTRODUCTION
9
Similarly, the BohmHiley nonlocal hidden variables interpretation 5 of quantum mechanics describes the universe as epistemically divisible but ontologically undivided. Quantum physics as an epistemic enterprise glimpses this ontological unity via its fundamental characterization of the universe as a unified, ' implicate order' of actualities which would at first glance seem to disagree with the Parmenidean worldview, since or der implies division. But in the BohmHiley interpretation, past and fu ture are symmetrica]ly related, and therefore ontologically indivisible; any potential 'coming to be' in the future is thus already contained in what already exists and existed. Past, present, and future, though epis temically distinct within the context of our finite observational structures, are nevertheless ontologically unified in a quasiParn1enidean 'One.' Bohm writes: If it were possible for consciousness somehow to reach a very deep level, for example, that of prespace or beyond, then all "nows" would not only be similar they would all be one and essentially the same. One could say that in its inward depths now is eternity . ..(But eternity means the depths of the implicate order, not the whole of the successive moments of tim e. )6
Further, for Parrnenides, the reduction of potentiality to actuality im plied related reductions of other mutually exclusive principlepairs, such as creativity vs. discovery. As noted above, in Pannenidean philosophy every 'imagining' is ontologically reducible to thinking about existence. And similariy, within the depths of the veiled implicate order underlying the BohmHiley undivided universe, all potentia are ontologically reduc ible to actuality; novel creativity is ontologically reducible to discovery of the already extant. The ground of any experience interpreted as crea tivity (inste�d of understood as discovery) is the epistemic restriction or contextualization of all experience within our necessarily finite observa tional structures. Bohm writes:
CHAPTER
10
I
s lves t o som u ric t res t w o r e e e fmite structures of this kind, As ong as l
d deep the d de y may be, then there is no question of an however exten E ach c te ism i on xt has a certain ambiguity, which . comp lete determ n in ar t, be removed by combination with and inclusion within p m ay , , . If w e were to remov · II s t · b · d a am rgUit an uncertamty, e x · te o c er oth y n l ld o no u r e i 7 b ng i wo ty tiv e c e v . oss ble r p a ho we e r, ·
1.2
l i s m a r D u and th e S cientific M eth o d : la Bipo l gy o o m Cos
th of od · m redu ct · e · th . e f o d wn an ass1m11at1on m . science, The success apparent he t a d re su by bility to predict and control nature at least as mea e has i l d tho t e i m s � v ab y led to a host of physicsinspired , yielded by thi ca h o red uctions o g c o sm l l i h d such as those discussed p ilosop i cal a n c smologies born ca ph i l so e of the 'many worlds' and above. The ph i lo ons at et u q t e in r ant u m mechanics are just two of t rp 'implicate or der' . mples of reductive ph1"I · 1 · a osoph rcal cosmo ogws msjJ!fed many modern ex c reductionis fi · t · en i · c s i I d rn. ndee d, m for scwn ced d omm e ant by and groun . th es s e t o f fundamental mutually ex h a r e l e n clusive worldview s i n g r , · . . p ted rr inte · ela e tt t· m · r a 1 Io e h n v1a either of the two modes, t d an nc1ples, pn has today b e e o a d v e come their defining characteris , 2A and 2B describ b s for example , ing p a , can be considered respectively: ir tic. The following antum m echan · q u vs 1cs; fundamentally continuous · classical mechamcs · · temporal extension in general relat·IV 1ty . f vs undamentally discrete . spatw . ua nt u n q on I s m m echanics; waveparticle dualism; spatiotempor al exten i s n n ocal q a t li a localefficient caus ty v . �  u n um causality; classical detern mmsm; ob ie e t de · . . · i n · J ct m r e v vs. contex tua1; mfim1t e vs. m1msm vs. qua ntu . lity; form vs fa · ctua a s · ct . . . v · 1 firmte; potent1a1ty . ttent n to a s tu worldviews whose foundations eiEven when o ne rn iO nore the phil s g ethe i o ophical foundations of modem r ther exceed or a l tog
�
f �
·
·
:
·
.
sc1ence
·ous theisticdominant w · r an VIew ld v s ., e.g o . .
the thesis of mu·
p ncrple s en is l da n m n ta exemplified in related pairings, tually exclusive fu
I1
INTRODUCTION
including: deterrninism vs. free will ; necessity vs. contingency; perfec.
tion vs. imperfection; permanence vs. change; heteronomy vs. autonomy . . . Perhaps most infamously, within the rhetorical spectacle of the mod ern 'science and religion debate,' the opposition of cosmogonic creation and cosmological evolution finds breathless celebration in popular por trayals of quantum cosmology_ The primary fuel by which this debate is sparked into conflict is the stubborn characterization of creation and evo lution, as well as necessity and contingency, as mutually exclusive con cepts whose only proper mode of coherent rela�ion is the reduction or assimilation of one concept to the other. Many quantum cosmologists, for example, argue that the un iverse contingently evolved into existence quantum mechan ically as a primor dial, initial extant (whether as a singularity or some. other form), ex ni
hilo, via a quantum probab i lity function
viz., a 'universal wavefunc
tion' yielding an unconditional probabil ity that 'our' universe would actualize amid the primordially extant distribution of 'alternative' poten tial universes constitutive of th is wavefunction. Some of these theorists have gone stil l further, promulgating quantum cosmology as a scientific val idation of the ideological claim that a primordial, necessary extant such as 'God' is inherently irrational. What is neglected i n this argument, however, is that when quantum mechanics is characterized in this way, as a cosmogenic engine operative primordially, in nihilo, then the logical structure presupposed by quantum mechanics m ust itself be understood
as a primordial, necessary extant a presupposition which, of course, belies the qualification ' in nihil a. ' In other words, when quantum me chanics, a logicorelational structure expressible in the language of math
ematics, is depicted as somehow operative in abstraction from a universe of relata, then this structure itself is necessari ly ontological and primor diaL One cannot, of course, coherently embrace both this ontological notion of logic and the notion that logic is a purely epistemic epiphe nomenon of the h uman mind. Yet this is precisely what many quantum cosmologists propose to do i n their efforts to reduce all necessity to con tingency.
CHAPTER
12
1
Finally, one might also consider those worldviews in which neithe� . science nor religion is seen as foundational. These might simply
bt
termed ' humanistic,' where fundamental mutually exclusive principle� are housed, in the most general sense, within the dualism of subjectivit) and objectivity. This pairing has its more specific application within
a ·
variety of disciplines in the humanities: In literature, deconstruction vs. intentionalism; in philosophy, conceptual vs. physical; mind vs. matter; thought vs. extension; the order of logical implication vs. the order of causal relation; necessity vs. contingency, pertnanence vs. change, unity vs. diversity, and so on. I n all of these examples, one can find within the history of Western thought a wide variety of systematic attempts to bridge fundamental mti· tually exclusive conceptual relata by way of either the method of com.. plementarity in the context of transcendent realism (Method 2A above) or by reduction and assimilation (Method 2B). In the early modern peri od, the overlygeneral division of philosophy into the rationalist vs. em· p iricist traditions, each with deep roots i n classical philosophy, well re flects the popularity of these methods. Though a careful survey of the philosophy of this period falls outside the scope of this chapter, readers familiar with the history of philosophy will be able to experiment with the above two classifications
Methods 2A and 2B; for example, Spino
za attempted to assimilate the causal order to the logical order, the con· tingent to the necessary; Locke attempted to assimilate the logical order to the causal order both examples of Method 2B. Kant's Transcenden.. tal Philosophy can likewise be seen
as
an example of Method 2A,
the
m ethod of transcendent realism (i.e., in the sense of his transcendental idealism, by which 'things in themselves' transcend the understanding). Fundamental complementarity, within this context, is evinced throughout his
system
his
discussion
of
'conditioned'
and
knowledge in the Transcendental Dialectic, for example.
'unconditioned'
·
INTRODUCTION
1.3
13
The Fallacy of Misplaced Concreteness
As is especially clear in the example of Kant, the chief deficiency of the categorization of incommensurable principles as fundamentally mu tually exclusive at the 'deepest possible' level of analysis is its presump tion that the bounds of reason have been reached. Fundamental comple mentarity marks this boundary in Method 2A, where the problem of mutually exclusive foundational principles is relieved only by reference to some ineffable, transcendent unification or implicate order that lies on the other side of the boundary either beneath the veil of finite observa tional contexts or, even worse, beyond the supposed scope of reason it self. But this merely exchanges one incoherence for another: the incoher ence of incommensurable categorical principles is traded for the incoherence of qualifying (i.e., knowing) the 'unknowable' as unknowa ble, via the reasoning of the unreasonable or, in modem science, the misuse of the hypotheticodeductive method to either posit or validate a theory that is, in principle, unfalsifiable.8 Method 2B is equally problematic the attempted reduction or as similation of mutually exclusive fundamental relata, one to the other, so that one is redefined as concrete and the other abstract one ontologi cally significant, the other an epistem ic derivative or artifact. Again, the method of reduction and assimilation rightly recognizes the need to bring into coherence mutually exclusive, incommensurable categorical princi ples; but it wrongly grasps for that coherence by arbitrarily restricting the speculative schematization of the experience of nature to certain pre ferred
categories of thought, in exclusion of other categories that could JUst as reasonably be characterized as fundamental. By this method, nature is always either fundamentally physical or fundamentally conceptu •
al; either fundamentally continuous or fundamentally quantum; either fundamentally finite or infinite; either fundamentally detenninistic or indetenninistic. When one considers the increasingly profuse inflations of physical cosmological models into metaphysical cosmologies, their stipulated significance is belied by the fact that one can casually assem hle practically any combination of the above qualifications and find a
14
CHAPTER
1
correlate interpretation of quantum theory or string theory or some other physical cosmology that can accommodate it. At the level of principles deemed fundamental to any given scientific theory, then, the method of purely reductive science breaks down. The reason i s because theorists enamored of the notion of an 'ultimate unify ing reduction' fail to recognize the ineluctable possibility of deeper lev els of abstraction underlying any ' ultimately reduced' principle or 'ulti mately unified' theory qualified as 'fundamentally concrete' by this method. It is a conceptual hazard that Whitehead famously ter1ned the 'fallacy of m isplaced concreteness,' and its pertinence to modern science has never been more important especially for those worldviews which, ·
in their ongoing construction, use science as bedrock, framework, and scaffold. For these worldviews, science is tasked not only with construct ing a fundamental descr iption of the universe; the target height of con struction is nothing less than a fundamental explanation of the universe via sheer deductive reduction. This bounding leap from fundamental sci entific description to fundamental scientific explanation is one that over the past several decades has perhaps been less careful than such a leap would warrant. And likewise, these increasingly routine efforts typically receive little critical attention despite the obvious logical obstacles that belie the reasonableness of even attempting such a feat. Again, one need only consider the growing number of philosophical ly loaded discussions of various physical cosmologies, the most esoteric of which have been embraced by the popular media for an entertainment· driven education of the public. The tacit stipulation of these presentations is that the demonstrable ability of the scientific method to construct sound reductionist descriptions of nature in itself warrants its broader application to the task of explaining or 'accounting for' nature' s very existence. What is neglected in this misapplication of the scientific method is the fact that a 'fundamental explanation' of nature constructed via the method of deduction, such as that instantiated in the hypothetico� deductive scientific method, is impossible. This is because the categori cal first principles at the base of any deductive scheme are always neces.. sarily presupposed. Science, for example, cannot 'explain' the logical
INTRODUCTION
15
order i.e., account for its existence since the language and methodol ogy of science necessarily presuppose this order. To clarify this point, let  us return briefly to the topic of quantum cosmology introduced earlier: In their 1983 paper "The Wave Function 9 of the Universe," Stephen Hawking and James Hartle propose a quan tum mechanical explanation of the origin of the universe whereby the universe spontaneously creates itself ex nihilo as a quantum mechanical probability function. (Hawking later asserts the theological implications of this model by stating that it allows for the elimination of the notion of God as a primordial extant in any rational explanation of the origin of the 10 universe. It is a claim that has since been repeatedly echoed by other cosmologists, primarily in massmarket books and media, and as such is arguably one of the driving reasons quantum cosmology has captured such popular notoriety today.) Elaborating upon the previous discussion, what is neglected by both this model and its characterization by Hawking and other advocates is the fact that a quantum mechanical wavefunction is more than just a 'ge neric' integration of undefined potential physical states that, when ap plied universally, yields an unconditional probability distribution of pos sible universes; the wavefunction, rather, is a fundamentally relational structure depicting conditional probabilities for the evolution of an actual final physical state e.g., that of the nascent universe not from 'noth ing,' but from some actual initial physical state. The wavefunction, in other words, is an integration of potential final physical states that is al ways conditionally contextualized by some actual, initial physical state. Further, it is a logically conditioned integration specifically a Boolean logical conditionalization presupposing final states that are always val uated as probabilities, and thus always mutually exclusive and exhaus tive. Quantum mechanics, then, whether applied to the description of microscopic systems in a laboratory, or to the description of the universe itself, always presupposes a logical order by which potential outcome states are ultimately reduced into mutually exclusive and exhaustive (i.e., logically coherent) probability outcomes. Indeed, it is only via a presup •
position of Boolean logic that probability theory is possible at all; and
16
CHAPTER 1
likewise, it is only via probability theory that quantum mechanics is pos sible. But again, more than just presupposing a logical order, quantum me chanics presupposes a correlation of this logical order with
some
causal
order of actualities from which potential outcome states derive. Quantum mechanics always begins with actualities, in other words tual system state ties'
in nihilo.
an initial ac
not simply bare, uncontextualized, 'generic potentiali
Indeed, it is impossible to define a potential outcome state
in quantum mechanics without contextual reference to both an initial ac tual system state and an anticipated actual outcome state, just as it is im possible to define
any particular potentiality without contextual reference
to some actuality. Assigning the name ' quantum vacuum' to an initial primordial actual state of the universe, thus attempting to characterize it as 'nothing' as is the convention in most quantum cosmologies, neglects the fact that this state is both actual and logically ordered; that is, the causal relations of this primordial state are defined quantum mechanical ly as an evolution from initial actual state to final actual state, and this definition presupposes the structure of logical implication (as well as other logical structures to be discussed later in this volume). Therefore, quantum mechanical
hilo cosmogonies,
cosmologies
cannot be properly described as
ex ni
productive of a 'randomly' generated �niverse from
nothing; indeed, even randomness mathematically presupposes an under lying logical order for its definition. The particular example of quantum cosmology can be seen as exem plifying a broader truth: that any attempt to construct a philosophical cosmology simply by clothing it as a ' purely scientific' physical cosmol ogy, borne of and supposedly validated solely by the scientific method and thus purified of any philosophical presuppositions, is doomed to in coherence. This is because any deductive scheme of reasonipg·, including the hypotheticodeductive method of modern science, must begin· with first principles that are necessarily presupposed, either implicitly or ex plicitly. The first principles at the foundation of any deductive scheme cannot themselves be deduced, since there is no more general principle by which such a deduction might proceed. Thus, again, science cannot
INTRODUCTION
17
' explain' the logical order i.e., account for its origins since the lan guage and methodology of science necessarily presuppose this order. In the above example, quantum mechanical cosmological models might offer valuable fundamental descriptions of the earliest stages of the evo lution of the universe; but when extended to the task of accounting for the origin of the universe ex nihilo, the model's reliance on a primordial logical order precludes its success. Whitehead's fallacy of misplaced concreteness, when applied to these increasingly p opular inflations of physical cosmology to philosoph ical cosmology, is crucial because it reminds us that science can never 'explain away' that which it necessarily presupposes. The logical order underlying mathematics can never be deductively explained or reductive ly accounted for by a scientific description of the causal order because the logical order is necessarily presupposed by the method of scientific description; thus, fundamental reductionist scientific descriptions of na ture can never attain the status of fundamental explanation, because there is always a deeper level of abstraction underlying any deductive or re ductive scheme, scientific or otherwise. One of the earliest and clearest illuminations of the deficiency of the reductivedeductive method when applied to the task of 'fundamental' or 'complete' explanation can be found in Plato 's Theaetetus. There, Plato challenges the idea that a suffi ciently deep reduction can serve as a stur dy bridge across the chasm separating description and explanation appearance and reality. In the dialogue, Socrates tells Theaetetus of a dream he once had wherein he had learned of a theory of explanation by which all things are described as complexes of simpler elements, them selves complexes of still simpler elements4 This reduction continues until the simplest elements are apprehended, at which point a complete and true explanation of the initial object is achieved. It is only then, proposes Socrates, that one can be said to possess true knowledge i.e., explana tion of the object. Theaetetus eagerly accepts this epistemology, but Socrates advises caution; he explains that in his dream, the most funda m ental elements are incapable of description by this epistemology, given
that they contain no simpler parts. Therefore, the most fundamental ele
CHAPTER
18
1
ments are themselves unknowable. How, asks Socrates, can the unknow able be the foundation and u ltimate justification of knowledge? Though Plato's admonition on the limits of a purely reductive,
deductive epistemology would ultimately be drowned out by the celebra tion of the manifold profound achievements of the modem scientific method over two millennia later, the historic advances in physics and mathematics emblematic of the twentieth century would also bring with them a number of sharp reminders of these limits. The misapplication of quantum mechanics to the construction of a 'purely physical' scientific cosmogony, discussed previously, is one example; but Plato's admoni tion would also find its rehabilitation in the key contributions of Godel . and Russell to the philosophy of mathematics
contributions crucial to
the construction of a coherent ontological interpretation of quantum theo ry. One sees this well reflected, for example, in Russell's paradox, which attends to the logical problem of predicating totalities. This difficulty, as will be discussed in detail in chapter 3 , finds its relevance in the quantum mechanical predication of system states defined as totalities universe itself when considered quantum mechanically
e.g., the
where the sepa
ration of ' measured system, ' 'measuring apparatus, ' and 'external envi ronment' is properly recognized as arbitrary. This recognition is conven tionally accepted in quantum theory, and indeed is explicitly embraced in the case of quantum cosmology, but its underlying implication that all wavefunctions are therefore ultimately 'universal' requires careful explo ration. Another exemplification of Plato 's admonition in the
Theaetetus
can
be seen in Godel ' s two incompleteness theorems, which together estab lish that no effectively methodical deductive theory capable of expres sion in the language of arithmetic can ever be both internally consistent
and complete.
The reason, evocative of Socrates' dream, is that any for
mal theory that is both internally consistent and allows for the deduction of arithmetical proofs will always presuppose some arithmetical state ment that is both true and incapable of proof by the theory. The specific relevance of Godel's theorems to quantum mechanics will be taken up in greater detail in chapters 2 and 3 ; but in the context of this introductory
INTRODUCTION
19
discussion, it is useful to consider their pertinence to the philosophical problem of relating the order of causal relation and the order of logical implication, as well as the problem of mutually exclusive categorical principles discussed earlier. Consider, for example, the various selfreferential paradoxes often associated with Godel's theorem, such as the Epimenides paradox, given in the ancient Cretan philosopher's infamous utterance: Kpf\'L£ A ==
SUBSTANCE AND LOGIC IN QUANTUM MECHANICS
53
Though these modes will be explored in more detail later in the chapter, for the purposes of the present discussion, only · [b] and [ c] in volve internal relations, so we will begin with them. With respect to [ c], the mode of implicative internal relation, note that in distinction from the logical connective ) signifying material implication (a purely syntactic, truthfunctional in1plication) employed earlier in th� relation of contextu alized observables (where a > b is read 'if a then b'), asymmetrical in ternal relation between measurentent contexts A and B, as well as be tween an actualized outcome state a,n and its particular measurement context A, is both syntactic and semantic, and thus requires a different connective. To this end, the statement 'Context A is internally related to Context B, and Context B is externally related to Context A' is signified herein via the expression A => B, alternatively read 'A only if B. ' Like wise, the statement 'actualized outcome state CX0 is internally related to Context A ' is signified via the expression an ::::> A. While this is analogous to the concept of ' logical entailment' ( 'A en tails B,' or 'B is deducible from A' ), as well as to C. I . Lewis's notion of 'strict implication' (both notions being semantic rather than syntactic), internal relation cannot be simply assimilated to these. G. E. Moore de fines internal relation thus: For any internal relational property F belong 22 ing to x, the following must be true: [1]
(\fx) (\iy) ((Fx
�
(s Fy
l= y
=f:. x))
In other words, "if x has the relational property F, then from y 's lack of this property it can be deduced that y is not identical with x. " If this propo sition is true for a particular value of F, then F is an internal rela tio nal property. If false, F is an external relational property. It is interesting to note that in comparison with [1], there is a similar proposition which, as Moore argued,23 can be said to hold true for all relational properties F, whether internal or external: [2]
(\fx) (V'y) ((Fx F= (s Fy ) y # x))
54
CHAPTER 2
This expression is identical to [ 1 ] , except that the connectives :> (mate rial implication) and I= (entailment) are transposed. Expression [2] thus reads, "givent that x has the relational property F, one can deduce, as a matter offact i.e., semantic content, not just syntactic form that if y " lacks this property, then it cannot be identical with x. Recall that in quantum mechanics, this distinction between fortn and fact is reflected in the distinction between contextualized potential outcome states and ac tual outcome states, respectively. 'Facts' are evaluated observables i.e., actualized potentia; they are actualizations CXn of potential measurement outcomes an whose Boolean contextualization A allows these potential outcomes to be valuated as probabilities. Since, for internal relations, both [ 1 ] and [2] are true (again, such that the connectives � and t= can be transposed) it would seem that the statement ' an is internally related to A ' exhibits a mutually implicative relationship between the concept of material implication and the concept of logical entailment in quantum mechanics i.e., the mutual implication of syntax and semantics, of form and fact. In this way, internal relation in the relational realist interpreta tion of quantum mechanics can be thought of as connoting a kind of 'on tological implication' that subsumes but exceeds logical implication at the level of fundamental physics. In quantum mechanics, there are two basic categories of internal re lation, both of which are asymmetrical, and both of which are operative in every quantum measurement interaction: [ 1 ] global outcome state in ternally related to locally contextualized measurement outcomes (i.e. , extension of the local to the globa[); [2] locally contextualized measure ment outcomes internally related to the global initial state (i.e., re striction of the local by the global). By category [ 1 ] , locally contextualized measurement outcomes ' quantum facts' are understood as constitutive of a novel global totality consequent of measurement i.e., a novel augmentation of the initial global state. By category [2], locally contextualized measurement outcomes are internally related to the global totality of facts subsuming the measured system's initial actual (though indeterrninate) state. More spe cifically, both the potential and actual outcome states of a measured sys
SUBSTANCE AND LOGIC IN QUANTUM MECHANICS
55
tern are internally related to the system' s local Boolean contextualization of the global totality of facts constitutive of the measured system ' s initial state (cf., von Neumann' s projection postulate and Liiders rule). In quan tum mec·� anics, in other words, a measurement's own particular local contextualization of the initial global state is always understood to be internally constitutive of the measurement outcome. For example, in the �
.

.
expression introduced earlier,
it is always the case that
a
I an ) + /3 1 anJ.)
is internally related to the ob
jective but indeterminate totality of facts constitutive of [ lf/). As we will see in the following section, nonlocal probability condi tionalization is a wellknown exemplification of categories [ 1 ] and [2] together, where locally contextualized potential measurement outcomes of one component of a composite quantum system are internally related to (and thus logically conditioned by) locally contextualized actual out comes within a different component (cf. von Neumann' s projection pos tulate and Ltiders rule applied to nonlocal EPR correlations, chapters 2.5, 2.8, and 9.4). As the conceptual framework presented in this volume unfolds, we will see that [ 1 ] and [2] above are, in fact, dipolar aspects of a single, unified relational process inherent in every quantum measurement event. A key principle of this framework, as is evident above, and as will be explored further in the next section, is that locally Boolean cont extualized quantum mechanical internal relations always require ref erence to a totality of facts whose global relations are nonBoolean. This key principle is most easily understood as an analog to the concept of the measured system ' s state vector l lf' ) introduced in the previous section: Recall that l lf/ ) represents an objective though indeterm inate state of a mea sured system in abstraction from any particular local contextualiza
tion, and is thus nonBoolean. Likewise, the global state vector I \f' ), also Introduced in the previous section, represents an objective though indeterm inate state of a composite quantum system, where 'global' is defined •
56
CHAPTER 2
as the totality of this composite system. As we saw earlier, I 'I' ) , as an uncontextualized representation of the global state, is, like J w ), non Boolean; the individual local systems constitutive of the glob al compo site system, one will recall, are not mutually independent and therefore relations between them must be expressed as a tensor prod uct Writ . large, of course, 1 '¥ ) could just as easily represent the totality o f the uni verse itself considered quantum mechanically i.e., as an un c ontextual ized, objective though indeterminate state of the universe. In th at light, it becomes intuitively clear why there is no sense in which a ' gl ob al B oole an context' for a glo bal state vector I \f ) can be specified quantum me chanically in the same way that local Boolean contexts can b e specified for l lf/): it would be akin to measuring the universe itself as either ' here' or 'there' in the same way that any system within the universe can be so measured. (This is an exemplification of the logical and ph il osophical problem of predicating totalities, discussed in chapter 3 .) Furth er still, as seen in the previous discussion of composite quantum system s, quantum mechanics does not allow for the analytic depiction of a 'global Boolean contextualized state' as simply an exhaustive concatenation of all local Boolean contextualized states, as though these local states were mutually 4 ? independent As we will see, this limitation is equally intuitiv e even though at first glan�e it would seem less so. (Both of these rel ated proscriptions are features of the KocbenSpecker theorem, and wil l be ex plored in detail in chapter 3 .) What can be specified quantum mechanically is alway s a rnutually implicative relationship between local and global, such that neither can be abstracted from the other in any quantum measurement ev ent. This relationship has only two possible modes, and these correspond, respec tively, with the two categories of asymmetrical internal rel ation discussed above; and like the latter, these two modes are mutu ally implicative and always jointly operative in every quantum measurem ent event: [ 1 ] extension of the local to the global, wherein locally contextualized facts (i.e., measurement outcomes) condition global potentia nonlocally. This is evinced, for example, by nonlocal probability conditionalization in quantum mechanics, to be further discussed in section 2.8; 2] re[ '
•
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striction of the local by the global, wherein global facts condi6on local potentia and their local contextualization. This is evinced, for example via the phenomenon of environmental decoherence, which will be intro duced in section 2.7. The central conceptual challenge, then, for any ontological interpre tation of quantum mechanics, is not only the problem of measurement, nor is it the problem of actualization of potentia (i.e., the problem of the existence of facts); the central challenge underlying both of these prob lems, rather, is properly understanding, via a coherent and empirically adequate conceptual scheme, the mutually implicative relationship be tween local and global in quantum mechanics. This necessarily entails the construction of a forn1al philosophical and mathematical framework that adequately depicts how the logical features of this relationship can be shown to condition the causal features. In summary of the discussion so far, the fundamental dipolar process in which this framework is anchored the essential process of quantum mechanics is [ 1 ] the asymmetrical internal relation of a global outcon1e state to locally contextualized measurement outcomes (i.e., extension of the local to the global); [2] the asymmetrical internal relation of locally contextualized measurement outcomes to the global initial state (i.e. , restriction of the local by the global). Again, it is a fundamental principle of quantum mechanics per the KochenSpecker theorem that this dipolar process excludes the possibility of global Boolean contextualization , ei ther synthetically via extension, or analytically via restriction . The con h ey t inate en of this totality, are et n ; in other words, stituent facts not d cannot all be assigned definite bivalent truth values (i.e., either true o r ons relati ible false) such that PNC and PEM are satisfied among all p o ss nate i d etenni n of these facts. This totality, then, is not only epistem ically co cally n l as o locally is onto]ogically tha globally; it indetenninate t is, d ll relate y a e t stitutive of the particular quantum measurement event i n rn met asym of ss lar e to it. However, as we will see, it is via this dipo proc s fact d lize tua ricai internal relation that manifo ld local Boo lean contex t no if en ev IY J can be co herently and objectively integrated no nlo ca M PE d an C PN at th ch su comprehensiv ely as a global B oo le an totality .
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condition causal relations not only within local Boolean contexts, but also across these contexts, even when measured systems are spatially wellseparated. It is via asymmetrical internal relation, in other words, that a global totality of facts can be coherently internally constitutive of a local quantum process.
2.5
The C ompatibility Condition for Logical Causality in Quantum Mechanics
Asymmetrical internal relations among local quantum measurement contexts, combined with the presupposition that individual local meas urement contexts are structurally Boolean, together constitute the con ceptual foundation of the compatibility condition for logical causality in quantum mechanics, which will be introduced here, and explored in greater detail in chapter 4, as well as in part II, chapters 9 and 1 0. Here, ' logical causality' ought not be interpreted as meaning ' logic that is causal' ; it means, rather, 'causality that is logical.' More accurately, it means 'causality that is logically conditioned.' The compatibility condi tion is exemplified in physics most generally as the universal, categorical correspondence of [a] the asymmetrical order of material implication and logical consequence (for the purposes of the present discussion, these together can be referred to simply as 'logical implication') with [b] the asymmetrical order of causal relation .. The correlation of the asymmetrical relationship depicted by 'cause effect' statements with the asymmetrical relationship depicted by 'if then' statements has been an infamous philosophical problem since the time of Plato because while it is easily demonstrated, it cannot be proven by derivation or deduction from some more fundamental principle. Even classical mechanics provided philosophers of the early modem perio d with no readily discernible indication of why the physical order of causal relatjon correlated with the conceptual order of logical implication. As Hume famously argued, one cannot ever 'directly observe' causal con
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nection, any more than one can directly observe logical implication; ra ther, we infer causal connection only after directly observing system states in conjunctive relation e.g., before and after a measurement in teraction. This is well exemplified in quantum mechanical measurement, as discussed earlier, by the fact that one cannot d irectly observe superpo sitions of potential outcome states; rather, we infer these superpositions only after directly observing a conjunction relating [a] an actual initial system state prior to a measurement interaction, and (b] an actual final system state consequent of the measurement interaction. The resulting philosophical proposals of the early modem period ei ther attempted to assimilate the conceptual logical order to the physical causal order (e.g., the philosophy of Locke), to assimilate the causal or der to the logical order (e.g., the philosophy of Spinoza), to depict the correlation of the logical and causal orders as a schematization by which we experience the otherwise transcendent 'things in themselves' (e.g., the philosophy of Kant), or to admonish against the philosophical pre supposition of either order (e.g., the philosophy of Hume). Quantum me chanics, however, provides a strong indication that the asymmetry of the order of causal relation presupposes the asymmetry of the order of logi cal implication, yet cannot in any way be reduced to the latter; for its fundamentally indeterministic nature, both at the level of theory and em pirical practice, utterly precludes any such sheer assimilation of contin gency to necessity e.g., in the spirit of Spinoza or Leibniz. Rather, quantum causality's necessary presupposition of the logical order entails simply that the causal and logical orders are properly understood as mu tually implicative at the level of fundamental physics. Again, it is an es sential presupposition of quantum mechanics that universally, every local measurement context is structurally Boolean that is, every local context can be represented mathematically as a Boolean subalgebra, or alterna tively as an equivalence class of Boolean subalgebras. It is by this pre supposition that all local contexts are globally relatable coherently and consistently (as is presupposed by every physical theory whose laws are presumed to hold universally).
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The compatibility condition is built upon two foundational concepts introduced previously, which will be further elaborated here: [ 1 ] locally, every measurement context must be Boolean, such that 25 in the mixed state, Boolean material implication holds e.g., for any measurement context A it will always be the case that for potential out comes a1 and a2 , a1 ) . a2 ('if a�, then not a2 ') and a2 > a1 . This, of course, is just PNC for an observable a with only two possible eigen states (Le., potential outcome states) a1 and a2• This number, however, is potentially infinite in quantum mechanics; again, because the contextual measurement basis is orthononnal (where n mutually exclusive eigen states e.g., representing n possible pointer positions on a particular de tector are depicted in the fortnalism as n mutually orthogonal vectors in a Hilbert space of n dimensions) one can represent the Boolean comple ment a1 by simply grouping all of the alternative mutually exclusive eigenstates into a subspace S l. of A, such that a1 ) a1J.. As noted ear lier, this presupposition of local Boolean contextuality, yielding mutually exclusive outcome states regardless of the number ofpossible outcome states, is a necessary prerequisite for the probability valuation of these alternative outcome states (the Born rule), which is a categorical presup position of quantum mechanics. [2] globally (i.e., when local contexts are brought into nonlocal rela tion), intracontextual Boolean material implication (that is, within indi vidual local measurement contexts) must be relatable intercontextually across these local contexts (i.e., 'globally'). In quantum mechanics, this is expressed as a tensor product relationship of potential outcome states. Thus, continuing with the above example, in a composite quantum system, for local measurement contexts A and B (and their associated detectors), if potential outcome ai is internally related to Boolean context A, and potential outcome bi is internally related to Boolean context B, as given in the expression: ...,
.
__,
(Gj => A ) 1\ (bi :::::> B)
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then the state of the composite quantum system, as we saw in section 2.3, is expressed as:
which yields the probabilities: P(a1 n b1) P(az n b2) P(a1 n bz) P(a2 n b1)




0.5 0.5 0 0
Once a measurement outcome has been registered by one of the de tectors say A the integration of potential outcome states at B is revised via its internal relation to the outcome at A, and this revision is manifest as a probability conditionalization. Thus, it is via the asymmetrical inter nal relation of B to A that the asymmetrical structure of material implica tion intracontextually within each local Boolean measurement context individually can be extended intercontextually, across these local contexts via the tensor product relationship of potential outcome states at A and B together. As a special case, depending upon the individual contexts, the inter. nal relation of B to A can yield probability valuations that take the form of logical entailment. For example, if an electronpositron pair is emitted during a particle decay, measurement of the electron' s quantum spin as 'up ' on a particular axis I measurement context entails that the positron 's spin will be 'down' if the same axis is chosen for the positron's meas urem ent context. (This logical entailment is reflected in the conservation of momentum law.) However, even when internal relations across local contexts take the fonn of logical entailment, these relations are always probab ility valuations yielded via the tensor product relationship of po tential outcom es across the component local contexts again, such that 
any 'global' state specification can only be inductively evaluated in tenns of the local contexts it subsumes. In other words, because neither local
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observables nor their measurement contexts are related deterministically, the 'global' state can never be analytical ly evaluated as simply a classical sum of its local constituent states. This is evinced most clearly in experiments on composite quantum .
systems that are often depicted as exhibiting 'nonlocal causal' relations, where, per the current discussion, local measurement contexts A and B i .e., detectors
�4
and B are spatially wellseparated, each measuring a
different component of the composite system. Because of their space like separation, it is assumed that given the relativistic speed of light limita tion, the order of component measurement (A then B, or B then A) should be irrelevant, since any physical causal correlations between components would require a fasterthanlight propagation of energy between A and B. 26 The most wellknown of these experiments are the EPR type experi mental arrangements, which will be discussed further in section 2.8 and chapter 3 , and fortnally depicted via the relational realist sheaftheoretic framework in chapter 9.4. What these experiments reveal is that while there is, indeed, no measurable nonlocal, efficient causal influence be tween A and B, there is a measurable, nonlocal probability conditionali zation between A and B that always takes the fonn of an asymmetrical internal relation. For example, as discussed above, if A registers first, the outcome at B is internally related to the outcome at A . This, again, is manifest as a probability conditionalization of the potential outcomes at B by the actual outcome at A; specifically, the integration of B's contex tualized potential outcomes, represented as an equivalence class of Bool ean subalgebras, is 'revised'27 by the actual outcome at A. This revision, indicative of the asymmetrical internal relation of B' s outcome to A's outcome, has been well demonstrated in numerous EPRtype experi mental investigations of quantum nonlocality. While some interpretations resort to exotic explanations (e.g., super luminal propagations of hidden energy, or other efficient causal, physi caldynamical mechanisms) the phenomenon of quantum nonlocality can instead be intuitively and coherently understood simply as a logical con... ditioning of causal relations a conditioning implicit in the logical rela tional structure presupposed by all scientific theories. This logical condi
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tioning of causal relations, defined above as the compatibility condition for logical causality in quantum mechanics, renders explicit the implicit presupposition of: [ 1 ] the Boolean relational structure of each local con text A and B (again, as a necessary presupposition of the scientific meth od in general) and [2] the coherent global relation of these local contexts via this structure.
28
From this perspective, in summary of the present example, the equivalence class of Boolean subalgebras representing the integration of potential outcomes at B is 'logically affected' (or better, onto logically revised) by the measurement outcome at A, thus exhibiting B's internal relationship to A, even when A and B are spacelike separated. This non local revision entails no propagation of energy of any kind from A to B and is thus not properly understood as an efficient causal influence of the actualized outcome at B by that of A; rather, it is a logical conditioning (viz., a non local probability conditionalization) of the contextualized po
tential outcomes at B via the internal relation of these outcomes to the actualized outcome at A. The advantage of the categorysheaf theoretic formalism introduced in the present volume is that it explicitly reveals the formal mereotopo logical structure by which these nonlocal internal relations are integrated via the compatibility condition in quantum mechanics; whereas in the more conventional Hilbert space framework, even when extended to in clude concepts such as overlapping equivalence classes of Boo lean sub algebras, this structure is only implicit and not fonn ally defined. Never theless, for the present introductory discussion, this more conventional depiction will serve as a useful propaedeutic to the categorysheaf theo retic forrnalism presented later in the book.
2.6
Inducing th e Global from the Local
It is via the compatibility condition for logically conditioned causal relations that local Boolean measurement contexts are representable as Boolean subalgebras, or equivalence classes of Boolean subalgebras,
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relatable globally via their overlaps. Such global relations in composite quantum systems aie always asymmetrical internal relations of [a] poten tial measurement outcomes contextualized by one local context, to [b] an actualized measurement outcome contextualized by another local con text. The mathematical representation of this conceptual framework is presented formally in part II of this volume by Elias Zafiris in terms of 29 Grothendieck topology and categorysheaf theory. As groundwork for this later discussion, it will be helpful to explore in greater detail the concept of overlapping equivalence classes of local Boolean contextual al gebras as an inductive representation of a 'global' state ( 'I' ). As discussed previously, the manifold locally contextualized poten tial measurement outcomes constitutive of a global composite quantum system are related intercontextually (i.e., across the component local .
contexts) via the tensor product. When a local context is represented as a Boolean subalgebra, or as an equivalence class of Boolean subalgebras, the tensor product relationship can thus be thought of as including an 'overlap' of these Boolean subalgebras, and this overlap is representative of compatible potential measurement outcomes (i.e., those satisfying PNC and PEM intercontextually). In classical mechanics, by contrast, the global state is characterized as a straightforward conjunction of all local Booleancontextualized states, such that the global . totality of all contexts is itself fully Boolean (i.e., the whole is simply the sum of its parts). In quantum mechanics, however, the global can only be depicted via induction, not conjunction; and it is via the overlap of Boolean subal gebras representing the various local measurement contexts constitutive of the global system that such induction is possible. As we have already seen, one reason the global can never be deduced from the local quantum mechanically, but only induced, is that observa bles contextualized by multiple local measurement contexts do not com mute; and as Kochen and Specker30 have shown, . it is impossible even in principle to embed local contextual Boolean subalgebras into a 'global' Boolean algebra. (As will be argued further in chapter 3, the ontological significance of the KochenSpecker theorem with respect to relating lo
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cal and global states is intimately related to the logical problem of predi cating totalities.) Quantum theory's signature replacement of classical localglobal mereology with the concept of ' inducing the global' via overlapping lo cal contextual Boolean subalgebras, where potential measurement out comes in one context are always internally related to actual measurement outcomes in others, is central to the argument that topology is the proper means by which to formalize quantum mechanical relations, given their underlying asymmetrical logical order. This is because quantum mechan ical relations, as we have seen thus far, are not properly understood as relations of independently extant objects; rather, they are asymnzetrical internal relations of relations considered objectively. Thus, as object re lata, quantum mechanical internal relations are always structure preserv ing, as can be depicted topologically (i.e., mereotopologically via catego ry theory) allowing for inductions like overlapping Boolean subalgebras to have ontological and not merely epistemic significance. By contrast, the conventional metrical approach to quantum mechanics, with its ad herence to classical mereology, is incapable of depicting structure pre serving 'relations of relations' in this way. In the conventional set theo retic framework, for example, ' elements' the framework's fundamental object relata are only relatable externally, never internally; there is no formal means by which to depict an element's ' internal relational struc ture' i.e., its internal relations to other elements and their relations. (The category theoretic framework, unl ike the set theoretic framework, does precisely this, as will be further elaborated throughout the course of this volume.) Indeed, it is arguably because of the conventional tacit presupposi tion of classical mereology, where the whole is simply the totality of its parts, that it is often considered a theoretical deficiency of quantum me chanics that it cannot define the global as a totality of this kind i.e., via a single, comprehensive Boolean algebra. As discussed earl ier in this ch apter, this has inspired many theorists to conclude that Boolean logic must therefore be invalid at the level of fundamental physics. However, th e fashionable solution of replacing classical Boolean logic with a non
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Boolean quantum logic is, again, a dubious one given that Boolean logic is a necessary presupposition of the scientific method itself the very conceptual framework by which quantum mechanics, and every other scientific theory, is forinalized, implemented, and evaluated. Indeed, it can be argued. that Boolean logic is necessarily presupposed in the coher ent conception and expression of any theory, model, or rational construc tion of any kind including the nonBoolean logics intended to replace it. But 'presupposition of here ought not be misread as 'reducible to'; fo.r the argument is not that all rational relations offact are reducible to Boolean, bivalent forms of relation. The mutual implication of fact and form, respectively correlate with the mutual implication of actuality and potentiality discussed earlier, precludes any such sheer assimilation. The claim, rather, is simply that any scheme of coherent and consistent con ceptual relations, parti�ularly any scheme that is sufficiently coherent and consistent to accommodate the modern scientific method, necessarily presupposes Boolean logic. Again, this is true even for schemes con structed to invalidate Boolean logic at some fundamental level such as that depicted via quantum physics; for regardless of their breadth of for mal complexity, the depth of invalidation achieved by such schemes is nevertheless measurable only via a still deeper level of Boolean presup position, without which the purported invalidation could be neither co herently fortnulated nor coherently expressed. Thus, it would seem that a proper assessment of the inability of quantum mechanics to depict a fully Boolean global state cannot simply be that Boolean logic is invalid at the level of fundamental physics; it seems more likely, rather, that it is the conventional, classically mereo logical conception of 'global state' via the purely analytical relation of 
local and global that requires revision specifically, one amenable quan tum mechanics' double assertion of [1 ] the universality of local Boole?n measurement contextualization, and [2] the impossibility of defining a universal global Boolean measurement context. As is clear from the discussion thus far, the relational realist frame work makes both of these assertions via a depiction of the relationship between local and global that is both analytic and synthetic. Instead of
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recasting localglobal quantum mechanical relations as fundamentally nonB o olean rather than Boolean, it recasts localglobal relations as fun damentally mereotopological rather than metrical and classically mereo logical. In this way, the global is always coherently (i.e., Boolean logi cally) relatable to its locally contextualized constituents, while at the same time never wholly reducible to an analytic description of these con stituents. As a heuristic example of a topological induction of the global from the local, consider the fami liar Mobius strip. Taken as representing a global forrn, we can depict multiple local Boolean quantum measurement contexts o n this forn1 as fibers spanning the width of the strip (i.e., per pendicular to its length), bundled together and running lengthwise along its entirety . The total bundle of these ' local' fibers thus constitutes an inductive representation of the entire strip. But topologically, this induc tive ' global' fiber bundle takes the form of a cylinder, not a Mobius strip. This is because locally, a cylinder and a Mobius strip are topologically identical, such that the topological relations among the ' l ocal' fibers do not yield an inductive approximation of the glob�l sufficient to capture the distinctive twist characteristic of the actual global forrn of the Mobius strip. In the same way, the topological relations among local Boolean measurement contexts
I Boolean subalgebras in quantum mechanics do
not allow one to completely define a 'global' state simply as a totality of ' local ' states. Nevertheless, the fact that local quantum measurement contexts are coherently relatable
at all necessarily presupposes the
compatibility con
dition introduced in the previous section, without which it is impossible to coherently depict quantum mechanics as a universal, and thus onto log ically significant, theory. It is via the compatibility condition that all lo cal n1easurement contexts in quantum mechanics are characterized as fun damentally Boolean relational structures whose relational asymmetry lo cally is preserved when extended globally. 31 As has previously been demonstrated by Zafiris in other writings/
2
and further discussed by him in part II, this presupposition of local Bool ean measurement contexts relatable globally via induction (i.e., 'gluing'
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in sheaf theory) is represented topologically as a presupposed uniforin fibration of the global topological space into a structure of individual, local B oolean subalgebras. In the relational realist philosophical cosmol ogy this is a forn1al expression of the fact that the universe is a logically structured totality of quantum facts, but one that subsumes manifold di verse (though always logically relatable) local contextualizations. Fur ther, since quantum measurement events are always predicative i.e., always generative of predicative facts this totality is synthetic, such that it increases, in a structurepreserving way, with each novel, locally contextualized, quantum fact; it is not, in other words, a closed, prede fined totality, analytically or deterministically reducible to the individual states of its constitutive parts. This presupposition is most clearly evinced in quantum mechanics in three ways, as discussed previously: [ 1 ] quantum indetertninacy; [2] the presupposition of orthonorn1al measurement bases (i.e., Boolean meas urement contexts) in quantum measurement; and [3] the possibility of relating, as overlapping equivalence classes of Boolean subalgebras, multiple local B oolean measurement contexts in a logically coherent and consistent way that preserves both the asymmetrical relational structures (e.g., m aterial implication and logical consequence) within these local contexts, and the asymmetrical internal relations among them globally.
2. 7
D ecoherence: Causal Relation or Logical Integration?
With respect to the above discussion, the logical integration of [a] a matrix of potential outcome states in the pure state to [b] a reduced ma trix ofprobable outcome states in the mixed state, is a logical integration of potential relations conventionally expressed as a tensor product, by which equivalence classes of local Booleancontextualized potential out comes are relatable intercontextually among the various l ocal measure ment contexts constitutive of a composite quantum system. The reduc
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tion of pure state potentia to mixed state probabilities via equivalence classes of relations is conventionally attributed to the process of quantum 33 decoherence, of which there are a number of interpretative models. It should be emphasized, however, that despite this diversity of interpreta tion, all of these models presuppose the principles of Boolean logic in both the formation of equivalence classes of locally contextualized ob servables, and the elimination of logically incompatible relations (i.e., 34 ' quantum interference' violating PNC) from within these classes. With respect to the discussion thus far, decoherence occurs when the Boolean subalgebra representative of a particular, locally contextualized
measured system observable is integrated with equivalence classes of Boolean subalgebras representing all unmeasured environmental observ ables per their own individual local contextualizations. As unmeasured observables, the latter are undefined; nevertheless, they are presumed to be locally Boolean, and thus representable as equivalence classes of Boolean subalgebras whose overlap with the Boolean subalgebra repre senting the measured system observable can be defined. These unmeas ured environmental observables are, in other words, the countless envi ronmental degrees of freedom operative when the relations between a quantum mechanical measured system and its environment are included in the measurement formalism. This inclusion might seem unjustified instrumentally, given that the totality of these unmeasured degrees of freedom is, in fact, immeasurable practically. However, the inclusion of environmental relations in the quantum measurement formalism is not only justified; it is arguably pre scriptive if quantum mechanics is to be considered a fundamental physi cal theory rather than merely a methodology. This is because 'system,' ' detector,' and 'environment' are always fonnally entangled in quantum mechanics, such that their partitioning is purely arbitrary. Thus, the im measurability of environmental relations as an epistemic issue cannot be taken to imply the irrelevance of these relations ontologically, and this distinction is the hallmark principle of those interpretations of quantum mechanics in which decoherence is recognized as an essential feature.
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In certain of these interpretations, such as the dynamical environ 5 mental decoherence models/ systemenvironment relations are depicted as purely eff,i c ient causal relations via energy transfer between the envi ronment and the measured system. (Experimentally this is achieved, for example, by modeling environmental degrees of freedom as an oscillator 36 bath.) A popularly presumed implication is that if this energy transfer can be prevented or dampened (e.g., by bringing the system to a suffi ciently low temperature), decoherence might be prevented or at least d�layed leaving the system in an 'actual superposition' for an extended period of time. However, it is now understood that there are quantum system environm.ent relations that entail no energy transfer whatsoever, yet nev ertheless generate decoherence. Nuclear spins, when treated as environ 37 mental degrees of freedom, are one example. Since there is no energy transfer in nuclear spin bath decoherence, quantum mechanical relations between measured system and environment cannot be characterized as 38 purely efficient casual relations. Thus, experiments on nuclear spin re lated decoherence indicate that phase exchange between system and en vironment is more accurately understood as a Boolean logical condition ing of potentia via ' ifthen' relations, rather than a purely causal influence through energy exchange via 'causeeffect' relations. Recall that this is precisely the same understanding depicted in the EPRtype investigations of 'causal quantum nonlocality' introduced in section 2.5, wherein the physical efficacy of logical relations was likewise evinced in absence of energy transfer i.e., in absence of 'purely' efficient causal relations. (We wil l revisit EPR in greater detail in the following section.) Thus, logical causality in quantum decoherence well exemplifies the cen tral thesis explored thus far in this chapter: In quantum mechanics, all causal relationships presuppose logical relationships, and logical rela tionships can have physical significance.
71
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2.8
EPR and Quantum Nonlocality
In addition to the phenomenon of quantum decoherence briefly in troduced above, perhaps the clearest exemplification of the thesis of log ical causality is the familiar thoughtexperiment of Einstein, Podolsky 39 and Rosen (EPR) introduced i n section 2.5 in the form of its m ore re 40 cent experimental incamations : A singlet (total spin zero) system de
cays into an electronpositron pair, with the two particles propagating in opposite directions (z and z on an xyz coordinate system). The spin of each particle (i.e., its intrinsic angular momentum) is measured by a de tector at the end of each path (detector A and detector B). Each detector can be oriented to measure the particle's spin direction on perpendicular axes (e.g., either the xdirection or the ydirection relative to the z axis). There are three central principles operative in this experiment as it pertains to the conceptual framework presented thus far:
(1 ]
Once the particle's xspin component in measured, it is impossible to measure its yspin component, and vice versa (x and y spin com ponents are, in other words, complementary observables like posi tion and momentum, which were the observables of the original EPR thought experiment).
[2]
Because the initial singlet has zero angular momentum , the total angular momentum of the two particles must also be zero. Many fundamental particles such as electrons and quarks have only two possible spin directions, 'up' and 'down' (i or t) on any particular axis.41 This means that if detector A measures particle A with spin up on the xaxis,
(ax j),
then detector B, if it is also set to measure
spin on the xaxis, will always show (i.e., with probability spin down (bxi) .
[3]
=
1)
Detectors A and B are spatially wellseparated such that a meas urement outcome at detector A could only
causally affect a subse
quent measurement at detector B via a fasterthanlight energy
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transfer propagating from A to B. Since relativity theory proscribes the possibil ity of such a transfer, A and B are considered to be causally externally related i.e., nonlocally independent with re spect to efficient causality. As discussed earlier, the classical ontological understanding of the
evaluation of an observable like x and y spin direction via a measurement interaction is that the latter merely reveals preexisting and always well defined values. Thus the state of a system is understood classically as a
complete specification by which the values of all its observables are, in principle, capable of revelation by an appropriate measurement. This al lows the direct evaluation of some restricted set of observables to indi rectly reveal, by logical implication, the values of any other observables. This is the classical ontological understanding of Principle 2 above: Par ticles A and B have their x and y spin components at all times, such that direct measurement of Particle A as axj reveals, by logical entailment, that Particle B is bxi even if Particle B is not itself directly measured. Entailment, here, i s thus symmetric and purely epistemic. When interpreted according to the classical realist ontology, then, the complementarity of x and y spin measurements (Principle 1 ) should be avertible with an appropriate sequence of measurements .. Evaluation of both x and y spin components for . Particle A, for example, could be achieved via a combination of [1] direct evaluation of Particle A ' s xspin, and [2] implicative evaluation of Particle A ' s yspin via direct evaluation of Particle B' s yspin. For example, if Detector A measures the spin di rection of Particle A as axI and Detector B measures Particle B as by! , then by logical implication per Principle 2 above, Particle A ' s yspin can be inferred with certainty (probability = 1 ) to be byI. Yet when the experiment is actually conducted, the indirect, logically implicative measurement of Particle A ' s yspin component fails. When the xspin component of Particle A is m easured by Detector A (rendering its yspin component undefinable by Detector A), the attempted measurement of the yspin component of Particle B at Detector B likewise yields undefined values. It is only when the yspin of Particle A is meas.
SUBSTANCE AND LOGIC IN QUANTUM MECHANICS
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=>
ay i with
ured that Particle B' s yspin i s welldefined (such that byt
probability = 1). But if Particle A's xspin is measured first, it is always the case that Particle B' s yspin component is byt with probability = 0.5, and by i with probability = 0.5. Thus a classical ontological interpretation of these results would lead to the bizarre question: "Is Particle B causally influenced by the choice of locally contextualized measurement (xspin or yspin) at Particle A? And if so, what is the fasterthanlight mechanism by which this causal influ ence can be 'transmitted' nonlocally from Detector A to Particle B?" For it seems that the m easurement outcome at Detector A (i.e., the evaluation of either ax or ay), a function of the Boolean m easurement context chosen for Detector A (measurement context Ax or Ay), somehow 'nonlocally affects' the possible measurement outcomes
at
Detector B such that:
If Detector A m easures axj or ! then at Detector B, P(byt)
==
0.5 and P(byj)
=
0.5
If Detector A m easures byj then at Detector B, P (byt) = 1 If Detector A measures by� then at Detector B, P(byj) = 1 By contrast, the quantum ontological interpretation of this experi ment, per the relational realist framework presented thus far, depicts these results as illustrative of an intuitively simple idea: Potential out comes are always logically conditioned by extant actual outcomes, re gardless of any spatial separation of the regions associated with these outcomes. In absence of any superluminal, physical propagation of ener
gy from the spacelike separated regions characteristic of EPR experi ments , it is only via such logical conditioning that outcomes in both regions can be coherently integrated i.e., as coherently related facts •
satisfyin g both PNC and PEM, such that despite their individual local · contextua 1IZat1 ons and mutual efficient causal independence, these facts ·
74
CHAPTER 2
are coherently integrable within a shared global history. Thus, when searching for Socrates ('measuring his position') the probability of dis covering him in Athens is nonlocally, logically conditioned by his sight ing in Crete. Classically, of course, this intuition is unremarkable since by that worldview, still regnant in our common sensibility, all physical observables are thought to possess precise values at all times. But quan tum mechanically, as we have seen, measurement outcomes can only be understood as generated consequent of measurement, not merely re vea}ed subsequent to measurement an understanding th�t has been con sistently confinned empirically, against every attempted imposition of 42 classical intuition upon quantum theory. The actualization of a potential measurement outcome, in other words, is always understood as a novel fact in quantum mechanics. But this need not be considered counterintuitive to common sense in general (as EPRtype experiments are typically portrayed), just because it defies a particular intuition concerning classical observables. Indeed, an equally intuitive understanding of quantum mechanical logicalcausal correlation among diverse locally contextualized facts can be found in the common conception of a 'history of facts' ; for this concept always entails a natural presupposition that a global history will coherently sub sume (i.e., without violations of PNC and PEM) the locally contextual ized histories constitutive of it. Whether or not the objects depicted via these local histories are spacelike separated is irrelevant to this presup posed correlation. Indeed� to the extent that quantum mechanics is accepted as the fun damental theory by which we properly understand the notion of 'physical object,' it is not the history that depicts the object, but rather the object that depicts the history. The classical understanding of a history as an epistemic representation of an ontologically fundamental 'material ob ject' is thus reversed a quantum Copernican tum wherein it is the classical notion of material object that is understood to be the epistemic rep resentation of ontologically fundamental histories of quantum facts . Though the latter are always locally contextualized, they are always co herently relatable globally. Note that in the present example, it is only via '
SUBSTANCE AND LOGIC IN QUANTUM MECHANICS the presupposed Boolean structure of each local context
75
'either in Ath
and the overlap of these local Boolean contexts, that their associated locally contextualized facts are ens or not' and 'either in Crete or not'
coherently relatable globally i.e., within a wider shared history that integrates, without violations of PNC or PEM, the local histories of Ath ens and Crete individually. Likewise, in the case of the EPR experimental arrangement, this log ical integration is expressed as a nonlocal ('global') inductive relation ship among local Boolean measurement contexts. In this case, there are four possible contexts (Ax, Ay, Bx, By), each of which is locally Boolean . such that, for example, in Context A x, ax j � axt· As discussed in sec ....,
tions 2.3 and 2.5, it is via this local B o olean contextuality and the associ ated compatibility condition that relations of potential outcome states
across contexts is possible. Recall that these relations are expressible in the form of a tensor product:
with each Boolean measurement context A and B represented as a Boole an subalgebra. The tensor product relationship in the above equation de fines the overlap of these Boolean subalgebras, by which compatible measurement outcomes at A and B are relatable. An actualized measure ment outcome within any one of the four contexts, Ax, Ay, Bx, By , then, 43 has the effect of altering this overlap, producing what Jeffrey B ub de scrib es as a 'revision' of the overlap, which includes within it the poten tial measurement outcomes in the counterpart context. I n this way, every potential measurement outcome in the composite system i s internally related to every logically antecedent actual measurement outcome. It is crucial, however, to distinguish between ' logical antecedence' and 'temporal antecedence' here, for these are often casually assimilated. Temporal antecedence refers to an asymmetrical metrical relation of events that is, a 'distance' relation of events as objects according to the parameter of time (or more accurately, spacetime). Logical antecedence, ..
76
CHAPTER 2
by contrast, refers to an asymmetrical logical supersession of events which are themselves internal relational structures that is, an internal relation of relations, such as that implied by the notion of conditional probability or more broadly, propositional logic, operative quantum me chanically. For example, in a classical conditional probability P(BIA), 'the probability of B given A,' there is no requirement that A ' s logical conditioning of B be understood as a supersession of events AB since classical conditional probabilities are purely episternic; that is, as classi cally conceived, conditional probabilities presuppose that all observables have precise values at all times, such that any logical dependency of B upon A is reflective only of one's knowledge of A and B as already extant facts. The historical significance of the EPR argument and its modem experimental incarnations is the definitive demonstration that this classi cal conception of conditional probabilities is entirely invalid in quantum mechanics,44 where measurement must be understood as generative of novel facts (measurement outcome events) and not merely revelatory of already extant facts. Thus in quantum mechanics, logical dependence depicted by a conditional probability like P(BIA) can only be understood as a Boolean logical conditioning of potential measurement outcomes at B by an actual measurement outcome A, such that P(BIA) depicts a super session of ontological events and their asymmetrical logical relation. In this way, the traditional conflation of temporal and logical ante cedence, and more generally, the causal and logical orders a conflation that has dominated the philosophy of nature since the Enlightenmentw has been definitively invalidated by quantum mechanics. There remain, however, a number of fundamental physical theories that maintain this conflation most notoriously the general theory of relativity, which rep resents our current understanding of gravity. The latter' s tacit embrace of the conflation of the causal and logical orders, in sharp contrast to quan... tum mechanics' elementary differentiation of these orders, is the central conceptual root of the notorious incompatibility of these two fundam en... tal theories. But this root has thus far gone largely unrecognized because until now the quantum mechanical distinction between temporal and log ical antecedence had not been fonnalized in a manner practically app li
77
SUBSTANCE AND LOGIC IN QUANTUM MECHANICS
cable to the general theory of relativity. The sheaftheoretic topological formalism of the relational realist philosophical cosmology, however, does precisely this, and its successful application to the reconciliation of quantum theory and the general theory of relativity has already been 4 two recently published demonstrated in papers. 5 This will be discussed further i n chapter
1 1 . 6.
For the purposes of this introductory d iscussion, however, the central concept by which the relational realist formalism can be u nderstood
EPR is that ·whereas temporal antecedence in causal
within the context
relations is formally expressed
metrically and set theoretically,
in the
relational realist framework logical antecedence in casual relations is fo1In ally expressed
topologically and category theoretically
as an ante
cedence of internal relations. Further, in the same way that m etrical rela tions presuppose topological relations, asymmetrical temporal anteced asymmetrical
ence presupposes
logical
antecedence.
For
example,
metrical comparisons of diverse geometrical forms, such as the area of a circle compared to that of a square, presuppose a topological scheme of congruence relations by which these distinct metrical fozms can be mean ingfully correlated. To this end, topological relational structures are 'elastic' in a way that is structurepreserving across compatible geomet rical forms. Thus
a
circle and a square as distinct geometrical forms are
topologically homeomorphic, each morphable to the other i n a manner that preserves the internal structure of each. Analogously, with respect to physical causality, metrical comparisons of diverse spatiotemporal causal contexts e.g., the space like separated m easurement contexts o f the arrangeinent
EPR
presuppose a logical, topologically fonnalizabl e scheme
of congruence relations by which these local contexts, with their respec tive Boole an intracontextual asymm etrical logical relation s (e.g., mate
rial implic ation pared and
within
a given local context), can be m eaningfu lly com
coherently integrated
intercontextually,
across
contexts, via structurepreservin g asymm etrical internal relatio n. In section
2.4,
Boolean 46
it was noted that there are three possible modes of re
lat ion among local Boolean m easurement contexts:
·
CHAPTER 2
78
[a] disjoint:
A n B=0
[b] overlapping:
A n B=A ®B
[c] implicative:
A � B or B =:> A
Mode [a] depicts mutually external relations among local measure ment contexts whose Boolean intracontextual structures are not compat ible for integration intercontextually (e.g., no correlation of material implication in Boolean context A with m aterial implication in context B, or vice versa). A s disjoint contexts, in other words, there is no overlap of the Boolean subalgebras representative of each local �ontext A and B. With respect to EPR, this is illustrated by the case where Detector A measures axi or j,, such that at Detector B, P(byj,)
=
0.5 and P(byi)
=
0.5.
As a purely random conjunction, there is nothing logically inducible or deducible globally
i.e., intercontextually across A and B from locally
contextualized measurements at A and B individually. Mode [c], implicative relation, was previously introduced in sections 2.4 and 2 . 5 . With respect to the present discussion, logical antecedence is manifest via this internal relational mode as nonlocal, intercontextual logical entailment Thus, if Particle A is measured first, then either: hxj
=>
axt or hxi
=>
axi with probability
=>
ayl or byl
=>
ayj with probability
=
1 for contexts Ax and Bx
or byj
=
1 for contexts Ay and By
Where this quantum internal relatedness takes the fonn of logical entail ment, in other words, the global (i.e., relations across local measurement contexts) can be deduced from the local. Mode [b], by contrast, depicts those cases where quantum internal relatedness remains at the level of the tensor product i.e., where rela tions among potential outcome states remain coarse grained and thus veiled within the overlapping equivalence classes of local Boolean sub
SUBSTANCE AND LOGIC IN QUANTUM MECHANICS
79
.algebras. By this mode of internal relation, the global can only be in 47 duced from the local. It is thi s mode in particular that makes EPR experiments even more fascinating: When Detector A is set to either context Ax or Ay , and Detec tor B is. set to an axis that is neither Bx nor By but rather one rotated to some intertnediate angle () , the experiment demonstrates the following: The relations between Context A and Context B are neither implicative (e.g., as they are in the case of Ax and Bx), nor disjoint (e.g., as they are in the case of Ax and By) . The contexts instead exhibit the second mode of relation, [b], given above: They remain overlapping, such that the tensor product relationship yields neither strictly random conjunction as exhib ited when the contexts are disjoint, nor conjunction by logical entailment as exhibited when the contexts are implicative, but rather something in between a global state subsuming both A and B that is definable via internal relations between A and B, but only inductively. In summary, it is a central claim of the relational realist interpreta tion of quantum mechanics that the calculable and empirically verifiable nonlocal revision of relations among potential outcome states is not properly understood as a mechanism of efficient causality e.g., where a measurement outcome at Detector A is understood to 'causally affect' Particle B nonlocally via some presumed, but as yet undiscovered, super lum inal, physicaldynamical mechanism.48 Rather, our interpretation simply presupposes, as a categorical feature of logical causality, that once a measurement outcome occurs at Detector A (an outcome that is locally Booleancontextualized by Detector A), the integration of poten tial measurement outcomes for Particle B (locally Boolean contextualized by Detector B), as well as the unique actual ization of one of these potential outcomes, will be logically internally related to that outcome at Detector A. This presupposition of internal relatedness among quantum meas urem ent outcomes would seem to be crucial for any ontological interpre tation of quantum mechanics, given the clear experimental disconfirma tion of the classical ontological notion that measurement is merely rev elato ry of already extant welldefined values for all observables, and ,
80
CHAPTER 2
the associated notion that logical relations are purely epistemic. Again, quantum mechanics evinces that measurement outcomes are not merely revelatory of extant facts, but generative of novel facts. Thus, the coher.. ent interpretation of quantum mechanics necessarily presupposes (either implicitly or explicitly) an internal relational structure by which novel facts constitutive of a measured system's outcome state can be logically integrated with those constitutive of its initial state, and by which the diverse local measurement contexts associated with these states can be logically integrated globally. This presupposed internal relational structure is thus a mereotopolog ical structure i.e., one wherein partwhole and localglobal relations are fundamentally topological rather than metrical, such that locally contex tualized facts, as quantum 'units of relation' themselves, can be logically related globally in a structurepreserving way. In the relational realist interpretation, this presupposition is rendered explicit, and thus requires a proper mathematical fortnalism by which this mereotopological internal relational structure can be practically bridged to the conventional, met rical formalism; for until now, it is only by this latter formalism that the extensive features of physical relations have been depicted in modem science. •
•
2.9
Topological Relations vs. Metrical Relations: Quantum Mechanics and Spacetime .
That local measurement outcomes are logically relatable globally is not only a presupposition of the relational realist ontology; it is a presup position of the scientific method itself. Thus a careful philosophical ex ploration of the mathematiGal fonn of these relations via a coherent speculative ontological framework could prove extremely important to the solution of fundamental conceptual problems in modem physics. The phenomenon of quantum nonlocality, introduced in the previous section, is one example, as is the general incompatibility of quantum theory and
SUBSTANCE AND LOGIC IN QUANTUM MECHANICS
81
relativity theory. In both cases, by representing local quantum measure ment contexts as Boolean subalgebras, such that locally contextualized measurement outcomes can be internally related globally, one discovers a
crucial point
one central to the relational realist program: These in
ternal relations are not fundamentally metrical and continuous, pertaining to
elen1entary objects,
as conventionally understood (e.g., requiring a
pointset structure, where points are related by continuous spatiotemporal intervals); they are, rather, fundamentally topological in that they pertain to
elementary units of relation
i .e., elementary relations that are fun
damentally discrete, not continuous. As will be demonstrated throughout the remainder of this volume, the concept of a topological structure of internal relations i s ideal for mathematically fonnalizing quantum mechanical, nonlocal logical rela tions such as those depicted by EPRtype experiments, and those which lie at the heart o f the incompatibi lity of quantum theory and the general theory of relativity. But j ust as important, the concept of a topological structure of internal relations is equally wellsuited to the task of fortnal izing coherent and intuitive
interpretations
of these fundamental physical
theories. With respect to the issue of mathematical forrnalism, as mentioned before, the work of my colleague Elias Zafiris has generated significant advances in this exploration, using Grothendieck topology to construct a 49 categorysheaf theoretic interpretation of quantum mechanics. Ontolog ically, this implies that the scientific evaluation of fundamental physical relations does not, as is conventionally accepted and prescribed by gen eral relativity, require the presupposition of a metrical continuum as a fungamental b ackground or foundation for the description of physical proces ses. Quantum mechanics, we believe, exemplifies the idea that the fund amental background by which physical relations are evaluated is top ological, not metrical . This ought not be taken to imply, however, that metrical relations are fundamentally irrelevant to physics, or that they are to be understood as i lldefined shadows of relations whose actual essence
rs sheerly topological. Metrical relations, rather, are simply higherorder •
types of relation that presuppose fundamentally topological relations.
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CHAPTER2
(Analogously, the relation of classical and quantum mechanics is proper ly understood in this same way, such that the latter is presupposed by the forrner..) S ince the mereological structure of the topology proposed in the rela tional realist philosophy accommodates the concept of internal relations, it is more accurately described as mereotopological a topology of wholetopart, globaltolocal whereby internal relations among quan tum actualizations (e.g., measurement outcomes) are both [ 1] structure preserving in terms of their asymmetrical logical order; and [2] genera tive of novel measurement outcomes, in that quantum mechanical rela tions are synthetically predicative and not merely analytically revelatory of preexisting facts. Outcome states in quantum measurement, as em phasized earlier, are always properly understood as generated conse quent of relations among systemdetectorenvironment, and therefore ontologically significant; they cannot, per classical convention, be accu rately characterized as merely revealed subsequent to these relations and therefore merely epistemically significant. With respect to its applicability to the solution of problems like the incompatibility of quantum mechanics and general relativity, the rela tional realist approach begins with the assertion that continuous metrical relationships presuppose discrete topological relationships. Whereas met rical relations derive from settheoretic points on a continuum as their fundamental elements, topological relations derive from discrete regions as their fundamental elements. Further, the metrical concept of 'point' presupposes the topological concept of 'region,' or more broadly, 'rela tion,' in that one can define a topological region I relation without refer ence to 'point' ;50 but one cannot define point in abstraction from rela tion e.g., relation to other points, or relation to some presupposed coordinate domain definable via boundary conditions. The relational realist conception of an elementary unit of relation as fundamental actual constituent of nature should not, however, be inter preted as a sheer reduction or assimilation of 'object relatum' to relation, as has been prescribed by advocates of socalled 'radical antic structural realism. '51 Though the lure of this kind of conceptual reduction is well
SUBSTANCE AND LOGI C IN QUANTUM MECHANI CS
83
precedented in the history of philosophy, as discussed at length in chap ter 1, equally precedented is the reduction to incoherence that invariably ensues when the concepts to be assimilated are mutually implicative, like relations and relata (and likewise their respective counterpart pairs, po tentiality and actuality, continuous and quantum, subjective and objec tive.) The ability to coherently and consistently define relata as rela tions i.e., in the sense of 'relations of relations' via a fortnalism such 52 as category theory does not, as is sometimes claimed, obviate the pre supposition of ' object relata' inherent in the concept of relation or, more ambitiously, obviate the notion of 'objects' in fundamental physical theories; it merely obj ectifies relations so that they can function as object relata. Indeed, when objectified relations are not properly recognized as object relata, one is left with the incoherent notion of 'relations without relata' again, an incoherence that is easily avoided by recognizing that relations and relata are mutually implicative concepts. Since quantum relations, as we have seen, fonnally entail both objec tive and subjective (i.e., contextual) features, the notion of an elementary 'unit of relation' capable of serving as an object relatum in quantum me chanics would therefore require a dipolar character capable of accommo dating both of these features. To that end, relational realism as a specula tive ontological program begins with the Whiteheadian categorical principle that fundamentally, all elementary object relata are quantum as 'objective' data the individual brute facts of the world and quantum as unique, 'subj ective' (i.e., contextualized) integratio ns of internal rela tions with other object data. (This is the 'subjectsuperj ect' character of Whitehead's elementary 'actual occasions' as dipolar units of relation, which will be discusse d further in chapter 4.) In this way, the classical notion of 'contin uous relations among objects' defined metrically and set theoretically is more fundamentally definable topo logic ally and category the oretically as ' discrete relations among relations.' As applied to the interpretation of quantum mechanics discussed thus far, in the same way that a fact cannot be meaningfully defined without reference to or relation with other facts, a quantum measurement out come (a 'quantum fact' ) cannot be defined apart from its relation to the
84
CHAPTER 2
quantum facts constitutive of an initial, locally contextualized global state. This is the initial systemdetectorenvironment state i.e., the uni verse itself relative to that particular, locally contextualized measurement outcome. But likewise, ontologically, a quantum measurement outcome is generated by these relations as a synthetic predication of the initial sys temdetectorenvironment state, such that with each quantum measure ment outcome, the universe has been objectively augmented by a novel predicative fact. (This is discussed further in chapter 3 .) With respect to the relativistic spatiotemporal extensive aspects of these quantum mechanical relations, rather than beginning with a met rical continuum, like the background of spacetime in relativity theory, and attempting to quantize it to accommodate quantum theory, the rela tional realist approach instead begins with a topological space as the fun damental fonnal background. It then defines continuous metrical rela tions (e.g., spatiotemporally extensive relations) as higherorder potential relations of initial and final discrete, actual quantum states such that continuous relations among potentia, in other words, presuppose discrete topological relations among actualities. As a mathematical analogy, consider the relationship between � (the set of real numbers a continuum and thus uncountable), (Q (the set of rational numbers ..discrete and thus countable), and � (the set of integers also discrete and countable). The convention by which we intui tively relate these sets is embodied by the very first representation of mathematical relations typically presented to children in their early edu cation: the real number line. Thus, we intuitively take the 'foundational' set to be the continuum IFi and then define I e t> + f3 1 lfl 1,> I ¢ 1,> I e �,> must b e understood as generative of a new fact "outside the totality," and constitutive of a new totality of the "next order above" (or otherwise sep arated)31 yet "compatible" with the original argument. As applied to the ontological interpretation of quantum mechanics, the mathematical term ' order,' which in the Theory of Logical Types pertains to functions, can
be taken to mean simply ' levels' within the hierarchy of totalities . 'Com
patibility' is derived from the asymmetrical internal relatedness of h igher to lower levels; that is, each h igher level totality contains and is thus conditioned by the facts of the next lowest level, and so on down the se ries of inclus ions. As exemplified by quantum indetenninacy, the condi
tioning is not determinate, since the predicate is not contained within the order of the argument
i.e., the predication is synthetic . By contrast, the
Hilbert space forrnulat ion of the conventional Copenhagen interpretatio n
contain s no mechanism by which this logical asymmetry can be repre
PREDICATION IN QUANTUM MECHANICS
119
sented; again, this is the chief impediment to the Copenhagen interpreta tion' s depiction as onto logically coherent.
3.4
Relations as Relata: From SetTheoretic Classical Material Objects to Category Theoretic Quantum Relational Events
Beyond exploring its significance to mathematics, Whitehead would go on to rigorously explore the ontological implications of the Theory of Logical Types that he and Russell had developed in the
Process qnd Reality,
Principia.
In
for example, Whitehead offers a thoroughly sys
tematized cosmology that in many ways can be viewed as a logico physical exemp l ification of the thesis of the Theory of Logical Types (though certainly not reducible to the latter). As introduced in chapter in Whitehead ian m etaphysics, every predicative fact
2,
(alternatively
teitned ' actual occasion ' or 'final real thing') is internally related to, though not detennined by, a dative world 'one order below' that of the predicative occasion. Predication is ' dipolar' because each potential quantum actual occasion (i.e., each potential predicative fact I potential
causalphysical pole, by which the potential novel fact is spatiotemporally coordinated with, and efficientcausally influenced by, the actual facts of its relativistically re 32 stricted dative world; and [2] a logicalconceptual pole, by which the potential novel fact and its unique subjective context are logically coor dinated via asymmetrical internal relation with the totality of actual facts constitutive of its dative world including these facts' own subjectively 33 contextualized internal relations to their dative worlds. Type measurement outcome) comprises both [ 1 ] a
theoretically, these dative worlds are therefore properly understood as lower order totalities relative to the subject occasion. Thus, although Whitehead never fonnalized in structure
Process and Reality
the implicit logical
underlying his philosophical scheme of coordinationby
Internal relation, the latter nevertheless clearly entails a typetheoreti c, •
120
CHAPTER 3
hierarch ic a l . structurepreserving mapping, corre1 ate d With a sch erne of . efficient c au . . by th"I S corre 1 ation th at th e ord ers of 1 ogtca . I . IS s altty; an It d .tm p li. cati. o a d n · n causaI re at1on . . . . Wh"tteh ead tan are coh erent1y Integrate d In I philosophy. ·
·
.
In d ee d ' 1·11 .
and even
" ear1 1er · . work 1n th e context of h ts
. ·p za przncz · .1.u 7v1.at r hematzca, ·
goin back to Whitehead's first major work, A Treatise on Unig versal Algeb . . �n e
l"Q,
•
m
1t IS clear that
l an g
the
Process and Reality was
an attempt to de
uage of philosophy what Whitehead could not, in his earher work s' . . . d efitne In th e I anguages o f math emattcs an d I ogtc a1 one: namely' a re " . a l 1st specu 1 at1ve . onto 1 ogy wh ose termtna1 ob� ects are e lemental units . . . . of znternal relatzon, analyzable both 1n terins of extenstve . connect i o n to , . . other e IementaI units . c I.e · . , coord1nate d!VISIOn' In · WhIte. head' s p hil o s · . oph y ) , and In terms of structurepreserving re1 attons with · · other e l em e n I . . . an d their re 1 ations t a units . , . d " , genetic IVlSIOn I · ' ) . B ut th e c .e . abs enc e o f ri g orous 1 og1comat . . 1 .(:". · process and Reazh ematica 10nna1 Ism In . zty, by Which W h itehead' s complex philosophical scheme might have bee n tec hn i . Cally represented, ought not to be Interpreted as an abandonment o f fo r . . . . . m aI Iog1c and math emat1cs I e , tn th e sense th at th ese are zn . . . . prmczple c o unterproductive to the method of speculative philosophy. A .
·
·
ca essay ''l\ It . . ' lvlathemattcs an d th e Good," as we 11 as In th e previous1y d.IS cu sse d pe rs o . 1 . n al etter to Henry Leonard, 1s that Wh.1tehea d 's 1c.rustration wt. th the d og1n . . . . . . 1 genera1 Izatton · deosop � ... .tattc positiVIst restraint o f ph 1 ' l h 1ca . rtve d not froth . . . · of �".l some newly acquired pesstmtsm ab out th e enterprise . s t ma th emattc f · . · popularity of extendtng " I s el , but rather from the Increasing rnathemat lc s b eyond Its · · are · own 1"dent1'fitabl e 1 tmits · · . B ut 1'f th ese 1 tm1ts . . exp l rct tl i . . . •
·
·
.
sc erne
can
b
e
.
. the present undertaken productively (and as argued In vo 1um e, to g . . . reat advantage) w1thout succumbing to the temptation of . red uc tng th e . . Ph1Iosophtcal scheme to the formal structure. Hmts ' of 'Whitehead s later philosophical assessment of the limita' . tions of th e l"h . ... ".teth od of .c: · work, 1onna1 tsm h IS · . ear1 test are ev1 d ent even 1n . . ,..,.rea ... 1. tzse on r:.;; . hzversal A lgebra, as will be discussed presently. Overall, of .
PREDICATION IN QUANTUM MECHANICS
course, the
Treatise
121
exhibits an optimism about the method of fonnalism
as a means by which to cross the Platonic chasm separating the order of mathematical necessity and the order of existential contingency
the
order of logical implication and the order of causal relation. The ideal of mathematics should be to erect a calculus to faci litate rea soning in connection with every province of thought, or of external ex perience, in which the succession of thoughts, or of events can be defi nitely ascertained and precisely stated. 34
Whitehead would, several years later, reassess the extent to which mathematical fonnalism, as a conventional enterprise, is able to achieve this goal,35 shifting h i s focus next to logic in his work with Russell on
Principia Mathematica,
and then finally to phi losophy. Indeed, it i s in
A Treatise on Universal Algebra to the fol lowing passage from Process and Reality: teresting to compare the above quotation from
Speculative philosophy is the endeavour to frame a coherent, logical, necessary system of general ideas in terms of which every element of our experience can be interpreted. By this notion of ''interpretation" I mean that everything of which we are conscious, as enjoyed, perceived, willed, or thought, shall have the character of a particular instance of 36 the general scheme.
But this evolution of focus from algebra, to logic, to phi losophy, is all too often characterized as a series of constructions and abandonments rather than a progressive synthesis, wherein the languages of mathemat ics, logic, and philosophy, each with its own intrinsic lim itations, togeth er contribute to a coherent understanding of nature. As mentioned above,
Whitehead ' s early recognition of these limits is evident even in
tise on Universal A lgebra.
A Trea
There, he makes a careful distinction between
mathematical truth and philosophical or experiential truth, and explicitly states the former' s necessary presupposition of the latter:
.
. ... ·······
····�·· . ......
..
...
�
1 22
CHAPTER 3 Mathematics in its widest signification is the development of all types of fonnal, necessary, deductive reasoning. The reasoning is forn1al in the sense that the meaning of propositions fonns no part of the investi gation. The sole concern of mathematics is the inference of proposition from proposition. The justification of the rules of inference in any branch of mathematics is not properly part of mathematics: it is the business of experience or ofphilosophy. The business of mathematics is 31 simply to follow the rule.
Mathematical defmitions are always to be construed as limitations as well as defmitions; namely, the properties of the thing defmed are to be considered for the purposes of the argument as being merely those in 8 3 volved in the defmitions. Over four decades later, in his last published philosophical essay, "Mathematics and the Good," Whitehead revisits this notion of the limi tation of mathematical definitions, and the necessary presupposition of philosophical truths for the construction and proper synthesis of fonnal ized logical and mathematical truths. In particular, he discusses this limi tation and presupposition as they pertain to his work with Russell on the rule of Logical Types (the following passage indeed reads as though were a natural continuation of the passage above):
Unfortunately this rule [a function is only predicative when it is of the next order/type above that of its argument] cannot be expressed apart from the presupposition that the notion of number applies beyond the lim itations of the rule. F or the number 'three' in each type, itself be longs to different types. Also each type is itself of a distinct type from other types. Thus, according to the rule, the conception of two different types is nonsense, and the conception of two different meanings of the number three is nonsense. It follows that the only way of understanding the rule is nonsense. It follows that the rule must be limited to the no tion of a rule of safety, and that the complete explanation of number awaits an understanding of the relevance of the notion of the varieties of multiplicity to the infinitude of things. Even in arithmetic you cannot get rid of a subconscious reference to the unbounded universe. You are abstracting details from a totality, and are imposing limitations on your
it
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123
abstraction. Remember that a refusal to think does not imply the non 39 existence of entities for thought.
In the context of the current discussion, one can read the last sen tence as, "refusal to think
nonmathematically
does not imply the non
existence of nonmathematical entities for thought." But again, the above passage is no disavowal of his earlier work on logic and mathematics, despite its frequent characterization to this effect; it is, rather, an admoni tion against the folly of extending mathematics and logic beyond their own intrinsic limitations toward the goal of an 'explicatively complete,' 'ultimate' fonnal structuralist understanding of the world. These lim ita tions had, for Whitehead, become more precisely defined as a result of the progressive synthesis of his work in mathematics, logic, and philoso phy throughout his career; but it is clear that even in his earliest work, the idea of such limitations was always central to his thinking. Returning again to
A Treatise on Universal Algebra,
for example, we find the fol
lowing: Mathematical defmitions either possess an existential import or are conventional. A mathematical definition with an existential import is the result of an act o f pure abstraction. Such defmitions are the starting po ints of applied mathematical sciences ; and in so far
as
they are given
this existential import, they require for verification more than the mere test of selfconsistency. In other words, unlike 'conventional' or 'pure' mathematical defini
tion s, ' existential' mathematical definitions, like the definitions of specu lativ e philosophy, require empirical applicability and adequacy in addi
tion to
logical consistency and coherence. (As introduced in chapter I , the se are the four desiderata for speculative philosophical definitions
give n in Process •
and Reality.) By contrast:
A conventional mathematical defmition has no existential import It sets before the mind by an act of imagination a set of things with fully
CHAPTER 3
1 24
defined selfconsistent types of relation . . . Qua pure . 111 a them a ttcs . . . 40 ' mathematical definitions must be conventional. •
One of the limitati ons Whitehead specifies for
c onv�
. na l or pu �n t1o re mathematics, as discussed above, is the necessary pres . . . u of Pposition Its . . . . . underlying logical structure: "The JUStification of the r ules . . of Inference rn any branch of mathematics is not properly part of mat . . . he tnatics: It IS the . . bus1ness of experience or of philosophy. The busines s of . . rnathemattcs 1s . 41 . . simply to follow the rule." (Cf. the discussion of G o dei' s Incomplete. . . ness theorem i n c hapters 1 and 2.) A related philos o ph i c . . a 1 1 Imttatton of . conventional mathematics is that although a conve ntio . n a l mathematical . formalism can be u nderstood to represent certain fea t ure s o f nature, the . formalization, no matter how elegant Its coherence a n ct . sel f consistency, . . . . cannot be taken b y these vtrtues a 1 one as sc1ent1f1c' ev i d en ce that nature rs somehow reducible to these features let alone redu c i b i e to the math. ematical formalism b y which these features are describe d ·
,
_
•
In order that a mathematical science of any importan ce rn aY b e fou . . . nded . . upon conventional defitn1t1ons, th e entitles created by th e . l11 must have . . rffi propertzes whLC JLnLty to tJze propertles of e:x.i " h b ear some aJ . . thzngs. stLng . . . . . Th us the d zstlnctton b etween a mathemattca1 d efiIllitl o n W h i t an extsten. · l · · not · · IS tta Import and a conventtona1 d efitnttlon alw ay s v . ery obvtous . . . . from th e fiorm t n whtch they are stated . Though It IS pos s ib i e to make a . . . . I. n + d efi1nttton 10rm unmistak ab l y e1.ther conventional or ex is . t entia!, there fi . · t case a e e d · . In sue h h Is o ften no gain t n so d otng Intti o ns . . a . . . nd resulting � propositions can be construed e1ther as re1ernng to a w Orl d of ideas . . created by conventron, or as referring exactly or appro x i lllatel y to the . . . 42 world of extsttng things. .
·

·
The quantum actual occasions in Whitehead' s l at er h . or f tlosophy, P . . . examp 1 e, are ex1stent1a rather than c . 1 units of re 1 atton l asstcally . under. . . . . . . . . stood ob�ect1ve e n tities (I.e., With Intrinstc , primary ' qu ar . I lle s) . As quan. . . ta, th ese units of relatton are rndiVISI.bl e and thus pos se s s an 'obJ. ectrve . character; but they are generated by their internal relation . s W1th anteced. , . ent dative occastons, and thus also possess a subjec ti ve' . c haracter. ThiS .
.
,
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125
subjectiveobj ective dipolarity of the quantum actual occasion forms the basis of an internal relational structure among all occasions
one that is
both inherited contextually (i.e., subj ectively) from antecedent dative occasions and ingredient (i.e., objectively) in subsequent occasions via a structure preserving ontological scheme. Despite the absence in Whitehead' s later philosophical work of any attempt at a rigorous m athematical formalization of this structure, his philosophical reimagin j ng of the classical, material, ' elementary particu late unit' as 'elementary relational unit' clearly derives from his earlier efforts to m athematically formalize the l atter. In his paper "On Mathe matical Concepts of the Material World," presented to the .Royal Society of London in 1 905, for example, Whitehead first gives an existential mathematical definition of the classical material pointparticle ('Concept I')and then proceeds to argue that it is not their particulate existence that makes them elementaty, but rather their
relational
existence (' Con
cept II'):
If we abolish the particles (in the "classical" sense) . . . everything will proceed [logically and mathematically] exactly as in the classical con cept. The reason for the original introduction of "matter" was, without doubt, to give the senses something to perceive. If a relation can be perceived, this Concept II has every advantage over the classical con cept.43 In thi s work, Whitehead explicates the properties that essential ele mentary relations must have if they are to have existential significance. At the time of its writing, for Whitehead this meant p rop e rti es that would allow them to be schematized via Euclidian geometry. In later years, this
would b e expanded to m etrical geometry more broadly, and by the time of Process
and Reality,
he would argue that even metrical geom etry was
not the fundamental extensive relational order. But by that time, he had abandoned the effort to mathematically fortnalize the essential properties of existential relations beyond their mereological structure as internal relations:
CHAPTER 3
126
Considered in its full generality, apart from the additional [relativistic] conditions proper only to the cosmic epoch of electrons, protons, mole cules, and starsystems, the properties of [the extensive continuum] are very few and do not include the relationships of metrical geometry. An extensive continuum is
a complex
of entities united by the various al
lied relationships of whole to part, and of overlapping so as to possess common parts, and of contact, and of other relationships derived from 44 these primacy relationships.
It could be argued that because of Whitehead' s earlier insistence up on the essential metrical and settheoretic characteristics of mathematical definitions qualified as 'existential' (and therefore 'meaningful'),
he
failed to identify in his later philosophical work that these essential char acteristics, though more abstract than he had originally supposed, could nevertheless be represented formally. More important, they could be rep resented forrnally
in
a manner wholly compatible with his philosophical
cosmology, both in terms of its speculative approach and its conceptual structure. In the present volume, we argue that the categorysheaf theoretic ap proach to quantum mechanics provides precisely such a formalization, wherein topological relations are shown to be fundamental to higher or der metrical relations; and indeed, the essential characteristics of catego rysheaf theory 's mathematical definitions of elementary relations
i.e.,
the characteristics by which these definitions can be qualified as 'existen tial' are traceable to the very algebraic and Boolean logical structural
characteristics of nature that Whitehead had first explored in Treatise on Universal A lgebra. In a paper appraising the latter' s potential reconnec· tion to Whitehead's later philosophical work, Robert Valenza and Gran ville Henry write: It was Whitehead' s attitude towards the presupposed radical objectivity of mathematical objects that hindered him from being truly creative al gebraically and fmally isolated him from the newer relational attitude toward algebra that has found its contemporary expression in category theory . . .
PREDICATION IN QUANTUM MECHANICS
127
The surprise, and irony if you like, is that when Whitehead finally gave up
mathematics, he di?covered a relational viewpoint
call functorial
which we dare
that seems to us an ideal philosophical foundation for
the emphases of category theory. 45
First introduced by Samuel Eilenberg and Saunders Mac Lane in the 1 940s, category theory was developed by way of algebraic topology in order to explore structurepreserving relations among mathematical ob jects defined as abstractly as possible i.e., to the point at which these objects are defined most fundamentally as relations themselves. These are the 'natural transfonnations' of category theory the structure preserving relations whose relata ('functors') are themselves structure preserving relations among the following: [1]
categories of primitive mathematical 'objects,' A, B,
...
[2]
relations ('morphisms') among these objects, f: A · B, . . . ,
Compositional structure is preserved throughout this scheme of in ternal relations via the presupposition of [ 1 ] the logical principle of iden tity (PI), given in the form of the identity morphism IA : A A and [2] B and g : B C binary composition of morphisms, such that iff : A then the composition g of: A C is valid and maintains the associative law i.e. , h o (g of) = (h o g) of )
,
�
:.
'
The fact that composition of morphisms is associative but not com mutative is central to the applicability of category theory to the interpre tation of quantum mechanics and its noncommuting observables and In particular, to the Whiteheadian relational realist interpretation, given •
the centrality of asymmetrical internal relations in the latter. However, commutativity in this sense is not to be confused with the commutative diagram s of category theory, which instead show that different composi tions might lead to the same result e.g., iff: A B and g : A C and D and k : C h:B D, such D and k o g : A D , then h o j: A that h of== k o g . This can be shown in the commutative diagram: ,
�
�
>
·
,
>
CHAPTER 3
128
A
f
B
�
g
h
c
�
k
D
In terms of Whitehead' s philosophical schematization of internal re lations, the noncommutativity of morphisms has its importance in an
particular data i . e . , oc internally related to dative occasion B means that B is but A is not constitutive of B. But at the same time, the
actual occasion's asymmetrical relationship to casion A ' s being constitutive of A,
commutativity represented in category theoretic diagrams has equal im portance when considering actual occasions as
totalities
i.e . , as inter
nally related to a totality of dative occasions. With respect to the above diagram, for example, occasion A ' s internal relation to dative occasion is mediated by its internal relations to ternal relation to
tween
A and
C,
words, must be
both B and C.
D
In this way, A ' s in
D, mediated by B, cannot exclude the relationship be
and by implication,
compatible with A
�
B
C
and )
C. A
)
B
�
D, in other
D such that h of= k o g.
Writ large, the overwhelming complexity of a totality of such equivalences is m itigated in Whiteheadian metaphysics via the formation of equivalence classes ('transmutations') of all potential intennediate
D. Intermediate internal relations incom C ) D and ) patible for integration are those that, unlike A A ) B ) D, violate commutativity. These are, for Whitehead, potential internal relations between A
·
�
·
relations that are incompatible for integration in occasion A, and are thus eliminated via a process of negative selection . As has been discussed previously,46 and as will be explored further, this method of negative se lection via the fo11nation of equivalence classes, and the inductive proximation of
all
ap
potential internal relations relative to a particular lo
cally contextualized quantum measurement outcome, is also central to· the relational realist interpretation of quantum mechanics .
PREDICATION IN QUANTUM MECHANICS
129
Returning again to the asymmetrical (noncommutative) internal re lations among morphisms, however, it is important to note that despite their centrality in Whitehead' s philosophical scheme, as well as in the Theory of Logical Types in
Princ ipia Mathematica,
this emphasis was
not present in his earlier work on algebra. As Valenza and Henry point out, The familiar concept of a function [or morphism] is perhaps the most important notion in all of mathematics. That composition of functions .
is associative but not commutative is almost certainly the reason that associativity has priority over commutativity in the axiomatic devel opment of algebraic systems
a feature characteristical1y lacking in
Whitehead 's development of algebraic manifolds.47
This is especially notable given that in A
bra,
Treatise on Universal Alge
Whitehead does explore the relationship between identity and m ath
ematical equality the fundamental 'truism' _a nd 'paradox' apparent in commutativity (e.g.,
b = 2+3
and
b
/
==
3+2, such that b
=
b ). "
With re
spect to the example of commutativity, he explains: The truism is the partial identity of both b and b
'
,
ness. The paradox is the distinction between b and b
their common B 
so that b is one
is another thing: and these things, as being different, 8 must have in some relation diverse properties.4 thing and b

This 'truism' and 'paradox' also h ave their reflection in algebraic re lations, given that some algebras satisfy the identity of idempotency that is, their elements, when combined with themselves, do not change (e.g.,
a+a
=
a);
and other algebras entail violations o f this identity. In
the algebra of real numbers, for example, idempotency is not satisfied
(I
+1
# 1 ) But in the case of set theory, for example, idem potency is .
satisfied (e.g.,
A ;. A
A
U
A = A);
and likewise in algebraic topology (e.g., 1 A
:
earlier). It is defined morphism in category theory the i dentity , A , and also satisfied in logical conjunction and disjunction (A !\ A 
==
A VA
==
A).
Indeed, when viewed as an integration of these various con
130
CHAPTER 3
texts, the relevance of the truism and paradox of idempotency to the predication of totalities and Russell? s Paradox becomes readily apparent; and in the same way, the relevance of the internal relational type theoretic sol ution proposed in Principia Mathematica to the internal rela tional metaphysical scheme proposed in Process and Reality becomes quite clear: An actual occasion A is a totality i n that it is internally related to the totality of dative occasions constitutive of the world
but this
worldastotality is properly understood topologically as a discrete region bijectively related to occasion A. And each of A ' s dative occasions is likew ise internally related to its totality of data through its own bijective relations to the world (topologically a different discrete region), though this totality is one order lower in the typetheoretic sense (such that this region is representable as an open cover of A' s region). Thus an actual occasion, as a totality, can be related to itself as a datum without para dox, because it is an asymmetrical internal relation of higher to lower 49 order. In l ight of the discussion so far, one can see in Whitehead' s later log ical and phi losophical emphasis of asymmetrical relations an evolution of thought that had important roots i n his earlier work on universal alge bra. This ph ilosophical emphasis can, therefore, arguably find an appro priate formalized expression via category theory, which was developed as a means of expressing algebraic topological relations. As we have seen, in category theory, one expresses relations among objects, but also
relations among relations. One can, for example, define the category C as consisting of [ 1 ] objects A, B, C :
A
.
.
.
and [2] morphisms f : A
,
B,
and
C . . In the same way that morphisms f and g represent relations among objects A, B, C . . . , functors F and G represent structure preserving relations among categories. If one considers categories C and D , for example, the functor F : C ) D entails:
g
[1]
>
.
that every object A, B, C . . . in C maps to an object F(A), F(B ),
F(C) . . . in D, and
PREDICATION IN QUANTUM MECHANICS
[2]
every morphism f
F(j) : F(A)
·'
F(B)
:
A
>
50 in D.
B
.
131
. . in C maps to a morphism
And finally, a natural transfonnation 17 is a structurepreserving rela tion whose relata are functors. In the present example, functors F and G are related (again, such that structural composition of their constitutive morphisms is preserved) via the natural transformation 1JA such that: [I]
every object A, B, C . . in category C is related to a morphism YfA : F(A) ) G(A) in category D; and
[2]
for every morphism f
.
Y{B
0
F(j) = G(f) 0 YfA •5 1
:
A
'
B
. . . in C, it is the case that
As this formalism applies to actual occasions as predicative facts in Whiteheadian metaphysics, recall that predication is ' dipolar' because each potential quantum actual occasion I predicative fact comprises both
[1 ] a causalphysical pole, by which the potential novel fact is spatia
temporally coordinated with, and efficientcausally influenced by, the actual facts of its relativistically restricted dative world ( ' coordinate di vision'); and [2] a logicalconceptual pole, by which the potential novel fact and its unique subjective context are logically coordinated via asymmetrical internal relation with the totality of actual facts constitutive of its dative world including these facts' own subjectively contextual ized internal relations to their dative worlds ('genetic division'). Type
theoretically, as we have seen, these dative worlds are properly under
stood as lower order totalities relative to the subject occasion. But categorytheoretically, it must be recognized that these internal relations, whether analyzed coordinately or genetically, cannot be forma lized as ' intrinsic eleme nts' of the actual occasion as some 'tern1 inal' o bj ect rela
�m. Unlike set theory, which can provide such termina l internal formal
Ization of an objec t (e.g., as a Cartesian product, or other ' intern al' pair structure), category theory can only define objects via their relations to
other objects and other relations. Fonnally, this is prec isely representa
CHAPTER 3
132
tive of the philosophical notion that an actual occasion as 'object rela tum' is, itself, an integration of internal relations with other dative occa sions, which are themselves integrations of internal relations, such that the structure of these dative internal relations, no matter how far down, is preserved throughout. In other words, the classical and settheoretically definable concep tion of an object relatum
as
possessing some 'objectively and sheerly
intrinsic constitution' is as incompatible with the relational realist defini tion of the dipolar, subjectiveobjective (i.e., relational) actual occasion as it is with the categorytheoretic definition of an object relatum. In the categorytheoretic formalism, even the most primitive objects cannot be defined this way; rather, object relata are always fundamentally under stood as relations themselves. And as will be introduced in chapter 5 and presented in detail in part II, in quantum mechanics, the category theoret ic ' internal' description of a quantum object relatum as a structure of in ternal relations is formally representable as a Grothendieck topological, sheaftheoretic structure.
3.5
Summary
Unlike the mutually exclusive dualism of the Cartesian metaphysical scheme, where substance is either a unit of thought or physical extension, in the Whiteheadian, relational realist, dipolar monistic scheme the caus
alphysical
and
logicalconceptual poles are mutually implicative
the contextual unity of the actual occasion
as
within
a quantum whole; that
each pole is incapable of definition without reference to the other. As discussed in chapter substance
is,
2, for Whitehead, the fundamental unit of
the essence of actual existence
is the predicative, dipolar
quantum actual occasion, and the essence of 'being' in his ontology
is
' becoming'; more specifically, the essence of any fact is its generation ('concrescence') as a predicative fact
by its internal relation
to the entire
dative world comprising a total class one order lower in the logical hier.. archy. Thus the scheme of internal relatedness by which a ' becoming'
PREDICATION IN QUANTUM MECHANICS
133
occasion is related to its dative world is asymmetrical, with the higher order always internally related to the lower orders, and the lower orders always externally related to the higher order. This logical asymmetry of internal relations is reflected temporally as the oneway arrow of time in thermodynamics and in the decoherencebased interpretations of quan tum mechanics. More generally, it is reflected in the oneway arrow of efficjent causality wherein the order of causal relation is always pre served tern porally, such that effect can never precede cause
even i n the
case of relativistic physics. In Whiteheadian metaphysics, then, the past is closed
its actual facts settled
and the future is open, with all predi
cation conditioned, but not detennined, by the antecedently established facts of the global h istory. Prior to concrescence, the becoming predicative fact I quantum
a potential actuality. But 52 in the Aristotelian sense, and as rehabilitated by Heisenberg in the on measurementinprocess is only propositional
tological interpretation of quantum mechanics, both potential facts and actual facts are treated as species of reality. When actualized, the novel quantum fact likewise has its physical and logical causal efficacy in tem porally and logic ally subs equent pred ication
again, by serv ing as log i
cal subj ect whose predication yields a novel global totality of the next higher order. The becoming of every new quantum actual occasion I predicative
fact, then, is most fundamentally a local unification of the global dative
relative to that novel, locally contextualized predicative factin proc ess. For exam pie, I'¥) = a l lfl t) 1¢ t) l e t) + fJ l lJI .t) I ¢ J.) le .J) always evolves relative to an indexical actualization of 1 ) the detector, with its ¢ totality
,
contextual preferred basis; and with the actualization of the novel predic ative fact comes the actualization of a novel global totality. With every new fact, then, a new totality
not in the needlessly exotic sense of a
'multi verse' of disconnected alternative universes, but rather in the intui tive sense of a universal history augmented by a novel fact. Writ large, the universe as 'enduring structure' i s fundamental1y described as a serial historical evolution of totality, discretely punctuated with each new pre dicativ e fact, with each fact bijectively related to its discrete level in the
CHAPTER 3
1 34
logical and mereotopological h ierarchy . Revisi ting an d e xpandi ng the earlier quote fr om W hi tehead, "the m an y be co m e one , an d are inc reas ed by one. In their natures, entities are disjunct ivel y 'many ' i n r p ocess of . . . ,,53 passage int o conJun ctiv e un1 ty.
Notes 1.
T h is is a necessary p re su p p o siti o n fo r any o n to lo gic a l
in terpretation of quantum m ec ha nics , although these m ig ht disagree o n the defini ti o n of ' meas urement' productive of eigenvalues (and therefore eigenstates ). " i Th e Pro b le m o f S p K ec E o k an rn ch er d st e , m n o n 2. S B id d en V ariables in Quantum Mechanics," Journal of Mathematics and Mecha nics 1 7 ( 1 967): 59_ 87 . 3 . U nl es s th e sy st em is hi gh ly id ea liz ed , where ob serva bl es h ave on ly two mutual ly �xclus ive possibl e measurement values (i.e . , representable via a Hilbert space of 2 di m en sio ns·· cf. the di sc us sio n in chapter 2 . 3) In th is ca se the 0 and 1 eigenvalues can be exhaustively mapped onto these values . The K ochenSpecker theorem pertains to le ss id ea liz ed systems , represented by a H ilb ert space of at least 3 dimensions. Werner Heisenberg, Physics and Philosophy (New Yo rk: Harper Torchbooks, 1 958), 53 . 4.
Heisenberg, Physics and Philosophy, 5455 . 6. Se e, fo r exa m pl e, S . B ertaina et al ., "Quantum O sc i ll at i on s in a Molec ular Magnet," Nature 453 (May, 2008): 2036 . 5.
Jeffrey B ub, "Quantum Logic, Condition al Prob ab i lity , nt rfer and I e " ence," Philosophy of Science 49 ( 1 982) : 4022 1 . See also: Jeff rey Bub, The problem of pro p erties in quantum mechanics,'' Topoi 1 0, no. 1 ( 1 9 9 I ) : 27_34_ 8 . B ub , "Quantum Logic," 4022 1 . 9 . See, for example: A. Aspect, J. Dalibard, and G. Roger, ' ' Experimental Test o f Bell's Inequalities Using TimeVarying Analyzers,'' P hysical Review Letters 49, no. 25 ( 1 982): 1 8047. 7.
1 0. The s p ontaneous localization approach of Ghirardi , Rimini,
and Weber
is one example: S ee G . C. Ghirardi, A . Rimini, and Weber, T. " Unified dynam
PREDICATION IN QUANTUM :MECHANICS
1 35
ics for microscopic and macroscopic systems", Physical R eview D 34 ( 1 986): 4709 1 .
1 1 . As discussed in chapter 2, exclusive disjunction (XOR) is the appropri ate Bootean operator, rather than OR, because PNC i s satisfied in addition to PEM. 12. This will be explored further presently, and revisited again in greater de tail i n chapter 4.2. 1 3 . See, for example: R. T. Cox, "Probability, Frequency and Reasonable Expectation," A1nerican Journal of Physics 1 4 ( 1 946): 1  1 3 . 1 4. G. B irkhoff G. and J. von Neumann, "The logic o f quantum mechan ics," Annals of Matlze1natics 37 ( 1 936): 82343. 1 5. See, for example: Woj ciech Zurek, "Decoherence, Einselection, and the Quantum Origins of the Classical," Reviews of Modern Physics 75, no. 3 (2003) : 7 1 575. 1 6. Bertaina, "Quantum Oscillations," 2036. 1 7. See, for example: A. Caldeira and A. Leggett, '�Quantum Tunneling in a Dissipative System," Annals of Physics 1 49 ( 1 983): 374456. 1 8. P. C. E. Stamp, "The Decoherence Puzzle," Studies in History and Phi losophy of Modern Physics 37 (2006): 485; S. Takahashi, et al ., "Decoherence in
Crystals of Quantum Molecular Magnets," Nature 476 (July, 20 I I ): 7679. 1 9. John von Neumann, Mathe1n atical Foundations of QuantLan Mechanics (Princeton: Princeton University Press, 1 996). 20. Niels Bohr, "Discussion with Einstein," in A lbert Einstein: Philoso pherScientist, ed. Paul Arthur Schilpp (New York: Harper, 1 95 9), 2 I 0.
2 1 . See, for example: Karl Popper, Quanturn Theory and the Schisrn in
Physics: Fro1n the Postscript to tlze Logic of Scientific Discovery (London:
Routledge, 1 992). 22. Niels B ohr, "Can quantummechanical description o f phys ical reality be considered complete?" Physical Review 48 ( 1 935): 696702. 23. Jeffrey Bub, "Quantum Logic, Conditional Probab i lity, and Interfer ence," Philoso phy of Science 49 ( 1 982): 4022 1 . See also: Jeffrey Bub, "The problem of properties in quantum mechanics," Topoi I 0, no. 1 ( 1 99 1 ): 2734.
24. Alfred North Whitehead, Pro cess and Reality: An Essay in Cos1nology,
Corrected Edition, ed. D. Griffin and D. Sherburne (New York: Free Press, 1 978), 2 1 .
CHAPTER 3
1 36
25 . B ertrand Russell, "Mathematical Logic as based on the Theory of
Types," American Journal of Mathematics 3 0 ( 1 908): 224. 26. Russell, "Mathematical Logic," 223. 27. Russell, "Mathematical Logic," 224 (italics added). 28. Russell, "Mathematical Logic,'" 239. 29. Alfred North Whitehead and Bertrand RusselL,
Principia Mathematica
to *56 (London: Cambridge at the University Press., 1 9 1 3), 48. 30. Whitehead and Russell,
Principia Mathenzatica, 5 3 .
3 1 . Besides Russell ' s Logical Theory of Types, there have been a number
of set theories constructed to the same purpose. ZermeloFraenkel (ZFC) axio matic set theory is one example, and while it makes no mention of 'logical types,' it contains similar concepts, and some have argued that these constitute an implicitly presupposed type theory similar to Russell 's. The 'von Neumann universe' or hierarchy of sets is an example of such a concept in ZFC. 32. This is referred to as 'coordinate division' in Whitehead 's philosophical
scheme.
3 3 . This is referred to as 'genetic division' in Whitehead's philosophical
scheme. 34. Alfred North Whitehead,
A Treatise on Universal A lgebra, With Appli
cations (New York: Cambridge University Press, 1 898), vii. 35 . Alfred North Whitehead, "The Philosophy of Mathematics.' ' Review of
Mysticism · in Modern Mathematics by Hastings B erkeley. Science: Progress in the Twentieth Century 5 (October 1 9 1 0) : 23439. In his review, Whitehead writes, "I think that the formalist position adopted i n [A Treatise on Universal
Algebra], whilst it has the merit of recognizing an important problem., does not give the true solution." 36. Whitehead,
Process and Reality, 3 .
37. Whitehead, A
Treatise on Universal A lgebra., vi.
38. Whitehead, A
Treatise on Universal Algebra., vivii.
3 9 . Alfred North Whitehead, "Mathematics and the Good" in
The Philoso
phy of Alfred North Whitehead7 ed. Paul Arthur Schilpp (New York: Tudor, 1 95 l ) , 67 1 72.
40. Whitehead, A
Treatise on Universal A lgebra, vii.
4 1 . Whitehead, A Treatise on Universal Algebra, vi. 42. Whitehead,
A Treatise on Universal A lgebra., vii.
1 37
PREDICATION IN QUANTUM IV!ECHANICS
43 . Al fred North Whitehead, "On Mathematical Concepts of the Material '
World" in A lfred North Whitehead: An Anthology , ed. F. S. C. Northrup and M. W. Gross (New York: MacMillan, 1 953), 29. Originally published in Philosoph ical Transactions of the Royal Society of London, Series A 205 ( 1 906): 465525 .
44. Whitehead, Process and Reality, 66. 45 . Granville Henry and Robert Valenza, "Idempotency in Whitehead's Universal Al gebra," Philosophia Mathe1natica 1 , no. 2 ( 1 993): 1 7 1 .
46. See, for example: chapters 2.3, 2.4, 2. 1 0., and 3. 1 . 47. Henry and Valenza, "Idempotency," 1 68 . 48. W hitehead, A Treatise on Universal Algebra, 67. 49. Topologically, as we will see in chapter 5 , this asymmetrical scheme of inclusive, internal relations can be intuitivel y represented as a nested structure of open covers.
50. Contravariant functors are also possible, where the arrows are reversed. 5 1 . Saunders Mac Lane, Categories for the Working Mathenwtician, Grad uate Texts in Mathematics 5 (New York: SpringerVerlag, 1 998), 7 1 6.
5 2. For Heisenberg, potentia are not merely epistemic, statistical approxi mations of an underlying veiled reality of predetermined facts; potentia are, rather, onto logically fundamental constituents o f nature. They are things "stand ing in the middle between the idea of an event and the actual event, a strange kind o f physical reality just in the middle between possibility and reality" (Hei senberg, Physics and Philosophy, 4 1 ) Elsewhere, Heisenberg writes that the .
correct interpretation of quantum mechanics requires that one consider the con cept of "probability as a new kind of 'objective' physical reality. This probabil ity concept is closely related to the concept o f natural philosophy of the ancients such as Aristotle; it is, to a certain extent, a transformation of the old 'potentia' concept from a qualitative to a quantitative idea" (Werner Heisenberg, HThe Development of the Interpretation of Quantum Theory," in Niels Bohr and the Develop1nent of Physics, ed. Wol fgang Pauli (New York: McGrawHill, 1 955),
1 2. 53. Whitehead, Process and Reality, 2 1 .
CHAPTER 4
L o gical Causality in Quantum Mechanics : A Relational Realist Ontology
The process of the quantum mechanical actualization of a potential out come state (i.e., the predication of an observable) is affected by both [I] the potential actuality ' s causalphysical relations with the dative actuali ties 'physically' antecedent to it (prior in time) in tenns of metrical, spa tiotemporal extensiveness
i.e., within its backward light cone, per the
restrictions of relativity theory; and
[2]
its logical internal relations with
those actualities 'logically' antecedent to it (prior in order), per the re strictions of PNC and Boo lean material implication, among other logical restrictions. (As discussed in the previous chapter, these are, respective
ly, the Whiteheadian ' coordinate' and 'genetic' analyses of a quantum actual occasion.1) Unlike the causalphysical relations, the logical inter nal relations are not relativistically restricted, and include both local and nonlocal data. For exam p Ie, with respect to quantum decoherence, these ·relations include the unmeasured degrees of freedom environmental to the measu red system, which may or may not fall outside the observable's backward light cone. Both kinds of relation, physical and logical, are unified by mutual implication within each predicative fact I quantum ac tual occasion via its dipolar Iogicophysical structure, such that all predi cati on is reflective of logical causality.
140
CHAPTER 4
4.1
Internal Relation and Logical Implication in Quantum Mechanics
The internal relation of local potential predicative fact to global da tive actuality, which is the basis of the asymmetrical nature of this scheme, is reflected in the asymmetrical orders of syntactic, Boolean ma terial implication, and semantic, logical implication (i.e., entailment). And with respect to its application to the ontological interpretation of quantum mechanics, this metaphysical and logical asymmetry is crucial. As introduced in chapter 2.4, asymmetrical internal relation, given in the
q (read, 'p only if q ) can be understood as Boolean ma q (read ' if p then q') that is always true semanti terial implication p expression p
=>
'
�
cally
i.e., as a matter offact, not for1n.
Material Implication
Internal Relation =>
p
Q
T
T
T
T
F
F
F
T
T
F
T
T
F
F
T
F
F
T
p
q
T
T
T
?
As applied to the discussion of Boolean local measurement contextu ality, in the truth table above depicting asymmetrical internal relation, Q thus refers to the logical context by which p can be evaluated. This is denoted by using the capital Q in the case of internal relation, versus the l owercase q in the case of material implication. It. should be emphasized here that it is because material implication is purely syntactic, i .e., as a truthfunctional, that it is representable as a truth table, by which the truth or falsity of the proposition derived simply as a matter of mapping T and F as values, whether or not these values are
LOGICAL CAUSALITY IN QUANTUM MECHANICS
141
evaluations of actual facts. Asymmetrical internal relation, by contrast, is syntactic and semantic that is, relating both fonn and fact and thus its depiction as a truth table here is purely heuristic. It ought not, in other words, be taken to imply that internal relation is reducible to a simple truthfunctional. With respect to its reflection in the relational realist ontology, asym metrical internal relations, where p necessarily implies Q, presuppose a
global 'objectivity' of the impl icate Q at the pretheoretic level that is not presupposed in the material conditional; yet at the same time, it preserves an indeterminacy in the local implicans p (which, as a predicative func
tion of the argument in Q, must be of the next order above Q). This is because the truth value of the potential predicative fact p is not deter
mined by the global objective facts constitutive of Q; rather, the latter determine the conditions to which all predication must confonn. For ex ample, if p
=
' Socrates is in Athens' and Q
=
' Socrates is in Greece,'
Socrates being in Greece does not detennine his bei ng in Athens, though it does condition the possibil ity of the latter. (Conversely, his being in
Athens does deterinine his being in Greece thus the asymmetry of in ternal relation via logical implication.) This is analogous to the case in quantum mechanics, such that in the spin � system,
I'P)
=
a l lf/ i ) I ¢ i) le t) + f3 1 lf L) I ¢ L) l e t)
I'P)
is a vector of unit length , and thus representative of the actual (though indeterminate) state of the compo site global system and its facts prior to the m easurement outco me. !'P), for exam ple, thus represents the implicate in the statement l lf/ t) 1 ¢ t) j e t) => j'!') (read, l lf/ t ) I ¢ t) le t) only if j\}') ). These facts subsumed by j\f') cond ition , but do not deter min e, the nov el predicative outcome fact (in this case, either eigenstate
I (f t) I ¢ t) l e t) or l lf/ �.) 1 ¢ t) l e J,) ) generated by measurement. This inde
tennin acy is reflected, for examp le, in the fact that each eigenstate (i.e . , each implicans of the internal relation) is always valuated as a probabil ity, via the complex coefficients
a
and f3 , respecti vely
a
l lf i) I¢ t) !e t)
14 2
CHAPTER. 4
and /3 1 /f/ .l ) ¢ .l) le .1) with I a 1 2 + I /3 1 2 a b il ity, wh ic h necessar ily satisfies P EM,
""'
1 .Again, valuation as a prob .
rath er than as merely a potenti
ality, whi ch does not necessarily satisfY PEM, is onl possi l the evaluation is relative to a lo c e y b because a l B o o l ea n con text (e.g ., that g iven by the c h o s e n detector, who se p o int e r re a d s e ith er exclusively ' up' or ' do w n ' that is , ¢ t Y: ¢ i represente d in he above expression as t a 1¢ t) + /3 1 ¢ .J. ) ) . Further, this local c o nte:xt i s itself only d efinable n q uantum m echa i n i cs via reference to a glo b al c o nt ext I'¥) (represented by Q in the above examp le) . In other w ords , thou h the novel g p red ic ativ e is fact not by the argum ent Q , it is contex determined p ll tua y dependen u t p on Q for its definition. In the sam e w ay that Athens cannot b e d e fin ed w ithout implicit or ex plicit re feren c e to Greece, no local system c an be d efined without implic it or exp li c it r efe r en c e to a larger syste m s u b su m in g it. In quantum mechanics, th e l atter must be a closed syste , rn an d i nterpreted ontologically, the only close d system i s the universe its e l f. i . e . , the totality represented by 1'¥). And i n '¥) I = a I I// t ) I ¢ t) e t) + fJ i lf/ .1) ) ¢ .�i), the probability le valuated, p re d i c ative outcome states are d efined upon each e i genstate. as proj ections of I'¥) Thus in quanturn mech an ic s, each locally contex tualized pred icative fact is, by internal re l at i on, d e pendent upon the g l ob al totality for its d etmition . Via thi s c o n c eption of log cally cond iti oned , asymmetrical intern al relatio n, the n , t h e ontological mterpretat ion of q uantum mechanics de s cribed h er e i n p o sits that every beco rn i n g act u al occasion/propositional predic ativ e fact i s always intern all related � to a o bal, obj ective actua world an ac gl l tual system of facts With obj ect iv e truth values. It is in th s way that t h e bj i o ective facts of the actu al Wor l d serve to condition the local p o s s i b i l i t i e s intern ally relative to t h at actu genstate p pre d i c a l world . Thus every eiative of a local observa ble Wit h or F mak e s n c potential truth value T e e ss ary reference to a g lo b al actu al world Q, such that p i s internally r e l a d t e t o Q , where the imp lica ns p i s o f the next logical order above that of t h e implicate Q. As relat e d t o h t e discussion in chapter 3 , Q i s always locally Boolean contextua l ize d i n quantum mechani s c , rep re s ented by an equivalen ce
�
LOGICAL CAUSALITY IN
QUANTU M MECHANICS
1 43
class of maximal Boolean subalgebras in the partial Boolean algebra of observables defining the global system. Recall how a local measurement M on a subsystem S2 of a global system S1 + S2 will condition the local measurement outcomes at S1 via a revision of this equivalence class of Boolean subalgebras; it is only in this way that the facts of Q condition, via restriction of the local by the global, the possibil ities for p . In the above example of Socrates' location, Q represents the selection of a Boolean context for p among all the potentia referent to the global totali ty (i.e., I'P) ) . But in quantum mechanics, it is not the case that all possi ble local contexts can be related to each other in tern1s of a global, fully Boolean associative order of inclusion. In the above example, for any two local Boolean contexts p => Q and r => S, there are three possible logical internal relations: [1]
Q
[2]
s
[3]
�
=>
s
Q
(p => Q) A (r => S) ) 3(Q ® S)
(deductive) (deductive) (inductive)
The third, inductive type is an essential feature of the topological categorysheaf theoretic approach to quantum mechanics, and will be further explored presently, as well as more fonnally in part II of this vol ume. For now it is sufficient to note that it depicts a global totalityof contexts as a maximally Boolean overlap among all local contexts, each of which is representable as a local nonmaximal Boolean suba lgebra. As was explored in chapters 2 and 3, the utility of th is conceptual framework becomes especially apparent when applied toward the coher ent interpretation of quantum phenomena such as EPRtype nonlocality. Against many popular interpretations of the latter, the relational realist interpretation depicts EPR nonlocality as a nonmetrical, topologically fo11nalized logical conditioning of potentia; this is in sharp contrast to other interpretations that depict EPR nonlocality as an efficient causal influence requiring a superluminal physicaldynamical mech anism, or as evidence of 'retrocausality' requiring the abandonment of temporal
1 44
CHAPTER 4
asymmetry and its presupposed correlation with logical asymmetry. In particular, recent experiments in quantum optics have· been interpreted as evincing such 'retrocausality,' including the socalled ' delayed choice, doubleslit quantum eraser' experiments mentioned in chapter 2 . 1 . In the context of the current discussion of nonlocal logical causality, a brief exploration of quantum eraser experiments is worth exploring here. As introduced in chapter 2 . 1 , these experiments exploring quantum superposition and entanglement are based on the Young doubleslit ex periment of 1 803, which was originally devised to explore the dual waveparticle nature of light. As we would characterize it today, the ex perimental arrangement essentially entails photons propagating through either of two parallel slits prior to impinging upon a detector. When ei ther slit is closed, the photons are well localized at the detector, thus ex hibiting their classically particulate character; and when both slits are open, the photons forn1 an interference fringe at the detector, thus exhib iting their 'quantum superpositional' wavelike character. A straightforward example of a doubleslit quantum eraser experi ment, based on the above, is that of Walborn et al? Many theorists (as well as many science joumalists3) have interpreted such experiments as 'erasing, ' via a kind of 'retrocausality,'4 individual actualized measure ments, and with them the Slit 1 I Slit 2 path infor1nation contained in the outcome states recorded by these measurements. This path information is included in the state specification by 'labeling' each path in terms of a combination of linear and circular polarization of the photons particular to each path. Thus, in the same way that electron spin direction served as a Boolean measurement context in the EPR example, linear and circular polarization serve as Boolean contexts in the quantum eraser example. At emission, the photons are initially split into two entangled beams, a 'sig nal' beam S directed at the doubleslits, and an 'idler' beam p · whose lin ear polarization will be manipulated in order to 'erase' the path infor mation of the signal beam. In front of each slit, a quarter wave plate 'labels' a photon's passage by circularly polarizing it either left or right without otherwise disturbing it as it heads for the detector.
LOGICAL CAUSALITY IN QUANTUM MECHANIC S
145
At emission, the linear polarization of both beams is detennined, and because they are correlated, direct measurement of the idler beam P's linear polarization indirectly yields, via implicative internal relation, the signal beam S' s polarization. Thus, Sy => Px and Sx => Py Finally, be cause of the relationship between linear and circular polarization in this •
arrangement, it is also a matter of implicative internal relation that de pending on the linear polarization of S, passage through the quarter wave plates labeling Slit 1 (SL 1 ) and Slit 2 (SL2) will result in either left or right circular polarization of S after passage through the slits. Thus, Stefl (SL l ) A Sright (SL2) => Sx , and Sright (SLI) A St fl (SL2) => Sy . When this arrangement is in place, the signal photon paths are effectively la e
beled via logical entailment, and detection events are welllocalized, with no interference fringe. The 'eraser' procedure simply involves placing an additional linear polarizer in the idler beam path, oriented so that both x and y polarized photons will pass through, thus 'erasing' the linear polarization infor mation for the idler beam, which also erases, by logical entailment, the linear polarization information for the signal beam. This, in turn, 'erases' the logically implicative circular polarization labeling by the quarter wave plates at Slit 1 and Slit 2, described above. In this way, erasing the linear polarization information from the idler beam erases the path label1ng mechanism for the signal beam, and causes the characteristic interference fringe to appear at the detector. Finally, it is purported to be significant that the path of the idler beam is longer than the path of the signal beam, such that if the linear polarizer i s placed at the end of the idler beam, then for any particular photon pair, the idler polarizer's 'erasure' of path information will occur after its counterpart signal photon has already reached its detector.5 As a result, the characteristic interference fringe reappears as it does with reg ular erasure, but in this case, after the pathlabeled signal photon has al ready been detected. Again, this is often described as 'retrocausal ' or 'del ayed ' erasure, implying that already actualized quantum facts (i.e. , facts entailing path infonnation) have somehow been ' erased' from reality. •
CHAPTER 4
1 46
At once exotic and esoteric, this interpretation has proven under·
standably tantalizing to both specialists and popular audiences alike. The reason i s that the purported disconnection of the asymmetrical order of causal relation and the asymmetrical order of logical implication fatally undermines the foundational principle by which nature is coherently ac cessible to human reason in general, and to the scientific method in par ticular: the categorical correlation of these asymmetrical orders i.e., the presupposition of logical causality. Thus, as was argued in chapter 2, any purported scientific invalidation of this presupposition amounts to nothing less than a scientific invalidation of the scientific method itself which, o f course, makes the application of the latter to such an endeavor .paradoxical at best. For this reason alone, one could argue that the only truly coherent scientific interpretations of these double slit, 'quantum eraser' experi ments are those that make explicit their reliance on logical causality as a categorical presupposition, on the grounds that the method of science itself is ineluctably rooted in this same presupposition. The relational realist ontological interpretation is one such candidate, and its application to the quantum eraser experiment outlined above is fully consistent with its application to the EPRtype quantum nonlocality experiments previ ously described, and presented for1nally in chapter 9.4: The local Boole an measurement contexts of the experimental arrangement are identified, in this case as: ..
[1] Px Y: Py [2] Sx Y: Sy
[3 ] Stefl (SL l )
Y:
Sright (SL l)
[4] Sleft (SL2)
Y
Sright (SL2)
These measurement contexts, representable as Boolean subalgebras, are mereotopologically internally related such that in the logical order of evaluation (i.e., the order of detection events), every contextualized ob
LOGICAL CAUSALITY IN QUANTUM MECHANICS
147
servable evaluated is internally related to those logically antecedent to it. (This scheme of mereotopological internal relation is formalized sheaf theoretically, as will be introduced in chapter 5, and presented systemati
cally in part II.) Again, this is precisely analogous to the EPR example discussed in chapters 2 and 3, wherein a local measurement M2 on a sub system s2 of a global system sl + s2 will condition the local measurement outcomes at S1 via a revision of the equivalence class of Boolean subal
gebras by which all operative local measurement contexts are coherently integrated. In the present example, there are four such contexts (listed above) and their coherent integration is evinced by the fact that in all quantum eraser experiments of this kind, when one analyzes the total pattern of detected signal photons, it is always a welllocalized ensemble, with no interference fringe, regardless of any particular manipulations of the idler path. It is only when one retrodictively analyzes the specific subset of signal photons that are correlated with the subset of idler pho tons whose linear polarization is undefined (i.e., uncontextualized) that an interference fringe is detected for this subset. This is simply because for this particular subset, local Boolean contexts [ 1 ] and [2] above are undefined, thus altering the equivalence class of Boolean subalgebras representing the totality of local measurement contexts for the signal and idler photons. But this in no way 'erases' the fact of each signal photon's individual detection, each of which is always welllocalized and free of ' interference.' Rather, these experiments simply demonstrate how the alteration of local Boolean measurement contexts in an ensemb le of measurements produces an alteration of the equivalence classes by which these local contexts are logically integrated, and thus an alteration in the probability conditionalization of the correlate measurement outcomes. More important, these experiments demonstrate the presupposition that local measurement contexts are always Boolean, and that they are always coherently integrable.
1 48
CHAPTER 4
4.2
The Compatibility Condition Revisited
As introduced in chapter 2.5, asymmetrical internal relation among local quantum measurement contexts, combined with the presupposition that individual local measurement contexts are always structurally Bool ean, together constitute the compatibility condition for logical causality in quantum mechanics. As discussed previously, this is exemplified in physics most generally as the universal, categorical correspondence of [a] the asymmetrical order of material implication and logical conse quence (for the purposes of the present discussion, these together can be referred to simply as 'logical implication' ) with [b] the asymmetrical order of causal relation. Recall that the compatibil ity condition is built upon two foundational concepts: [ 1 ] locally, every measurement context must be B oolean, such that 6 Boolean material implication holds e.g., for any in the mixed state, ·
measurement context comes a1 and a2 , a1
A it will always be the case that for potential out> ,
a2 ( 'if ah then not a2') and a2
) , a1 . This, of
course, is just PNC for an observable a with only two possible eigen states (i.e., potential outcome states)
a1
and a2 . This number, however,
is
potentially infinite in quantum mechan ics; again, because the contextu al measurement basis is orthonormal (where n mutually exclusive eigen states
e.g., representing n possible pointer positions on a particular de
tector
are depicted i n the formalism as n mutually orthogonal vectors In •
a Hilbert space of n dimensions) one can represent the Boolean comple ment
,
a1 by simply grouping all of the alternative mutually exclusive
eigenstates into a subspace
S .L of A, such that a1
)
.., a1 l..
As noted earli
er, this presupposition of local Boolean contextuality, yielding mutua lly exclusive outcome states regardless of the number of possible outconze states, is a necessary prerequisite for the probability valuation of these alternative outcome states (the B orn rule), which is a categorical pres up position of quantum mechanics. (2] globally (i.e., when local contexts are brought into nonlocal rel a tion), intracontextual B oolean material implication (that is,
within indi
vidual local measurement contexts) must be relatable intercontextua l lY
LOGICAL CAUSALITY IN QUAN TUM MECHANICS
across
149
these local contexts (i.e., 'globally'). In quantum mechanics, as
discussed previously, this is expressed as a tensor product relationship of potential outcome states. But the tensor product by itself i n the conven tional Hilbert space formalism does not explicitly define the underlying Boolean logical structure of the localglobal correlations it presupposes. Specifically, it does not define the manner in whi ch a global totality of quantum events, which
cannot be represented
by a global Boolean alge
bra, can nevertheless be coherently correlated with local Boolean contex tual izations of this totality. Recall that globally, the lattice o f relations among the totality of quantum events is nonBo olean, evinced by both the noncommutativity of quantum observables, and because PNC and PEM cannot be s hown to hold globally in quantum mechanics. That is, one can never, even i n principle, evaluate the totality of quantum observ ables as a comprehensive scheme of mutually exclusive and exhaustive 7 True I False propositions. However, this
can
be done within local Boolean contextualizations
of this global structure; that is, local Boolean sectors of the nonBoolean global lattice can be defined. In this sense, the global quantum event structure, even though it cannot be fully embedded within a global Bool ean algebra, can be represented via a partial Boolean algebra
so long as
one categorically presupposes that all local measurement contexts are structurally Boolean (i.e., representable as a Boolean subalgebra, or as an equivalence cl as s of su ch subalgebras). This presupposition is the first component of the compatibility condi tion for logical causality in quantum mechanics, from which one can then proceed to define a structure by which Boolean localglobal relations can be specified. For even though the totality of facts contained in the global quantum lattice can never be defined completely via deductive analysis, they can be defined approximately via induction from the overlaps of a s fficiently large number of equivalence classes o f compatible, or par tia lly comp atible, local Boolean subalgebras. It is via this structure that �lob al quantum events can be shown to logically condition local poten tial measureme nt outcomes i.e. restriction of the local by the global (see chapt er 2.4); l ikewise, it is via this structure that l o cally contextual
�
150
CHAPTER 4
ized quantum events can be shown to condition global potentia
extension of the local to the global.
i.e.,
As we have already seen, nonlocal
probability conditionalization in EPRtype experiments well exemplifies both restriction and extension in this way. Foimally, the structure of these overlaps is not fundamentally metri cally extensive, but rather mereotopologically extensive. It is, in other words, a
topological scheme of asymmetrical internal relations.
This
characterization is the second component of the compatibility condition for logical causality. The formalization of this mereotopological scheme "
requires the mathematics of algebraic topology rather than metrical ge ometry because it entails the representation of a global partially Boolean algebraic structure via a nested covering structure of local Boolean sub algebras. As will be introduced in chapter 5, and fully forrr1alized in part
II, this structure is rigorously definable via sheaf theory, 8 by which glob
al algebraic relations can be defined inductively via a topological, inter nal relational covering scheme of local algebraic relations. Thus, continuing with the previous example, in a composite quantum system, for local B oolean measurement contexts A and B (and their asso ciated detectors), if potential outcome
ai
is internally related to Boolean
bi is internally related to Boolean con expression: (ai => A) 1\ ( bi => B), then the state of
context A, and potential outcome text
B, as given in the
the composite quantum system, as we saw in chapter 2.5, is expressed as:
This conventional tensor product expression presupposes an implicit top ological structure by which the local Boolean subalgebras representing A
and B overlap, such that their respective local, intracontextual Boolean structures are globally relatable intercontextually. The result is a re stricted set of possible correlations:
P(a1 n b1) P(a2 n b2)
=
=
0 .5 0.5
LOGICAL CAUSALITY IN QUANTUM MECHANICS
P(a1 P(a2
n b2) n b1)
=
=
151
0 0
In quantum mechanics, however, this topological structure of over lapping local Boolean subalgebras is always asymmetrically internal re.
lational
i.e., it i s a mereotopological structure, such that the overlap
ping regions are always 'nested' in a structure preserving way. This is . . evinced by the fact that once a measurement outcome has been registered by one of the detectors
say
A
the integration of potential outcome
states at B i s revised via its internal relation to the outcome at A , and this
revision i s manifest as a probability conditionalization. Thus, it is via the asymmetrical internal relation of B to of material implication within A and
A
that the asymmetrical structure
B individually can be correlated in
tercontextually via the tensor product relationship. With respect to the process of decoherence introduced in chapter 3 . 1 , the significance of the compatibility condition becomes particularly acute, and can be more fully described in light of that discussion. For it is via the process of decoherence that evolve fro m
potential
probable
m easurement outcomes
measurement outcom e s once equivalence classes
of the latter are coarsegrained, via negative selection, into a matrix of mutually exclusive and exhaustive outcome states. In ·other words, it is via decoh erence that classical descriptions o f nature in tenns of classical ly meaningfu l (i.e., mutually exclusive and exhaustive) probable out com e states that exclude violations of PNC, emerge from quantum me chanical descriptions of nature in terms of potential outcome states that initially include violations of PNC. However, while decoherence is today conventionally acknowledged as a canonical feature of quantum measurement, there as yet exists no convent ional
understanding of the process of decoherence itself. that is,
Whether it is primarily a dynam i cal physical mechan ism, or primaril y a log ical concep tual mechanism. Correspondingly, most of the fonnal dec oherence models proposed over the past decades have been inspired
by
two basic interpretive approaches: [ 1 ] environmental or dynamical de coh erence, emphasizing the physical interaction between the observa
1 52
CHAPTER 4
bles of a measured system and those of its environment; [2] decoherent histories, emphasizing the logical integration of all potential observable evaluations relative to a given measurement, regardless of their classifi cation as 'system observables,' ' environment observables,' or 'detector observables,' since these divisions are purely arbitrary in quantum me chanics.
9 The environmental I dynamical decoherence approach, introduced in
chapters 2 and
3,
is founded upon the principle that every physical sys
tem is always in a state of dynamical relation with its environment, such that the observables constitutive of 'measured system,' ' detector, ' and ' environment' are in a state of constant physical interaction. The com plex structure of the correlate quantum entanglement, while exceeding the possibility of conventional calculation, does allow for an averaging over the immeasurable degrees of freedom subsumed by the entangled systemdetectorenvironment state. This is represented via a traceover of the offdiagonal tertns of the density matrix, eliminating interference terms and yielding the usual m ixed state of mutually exclusive and ex haustive probable measurement outcomes. Thus, according to the envi ronmental decoherence approach, it is because of every measured sys tem 's
constant
dynamical
relations
with
its
environment
that
superpositions of counterfactual potential system states are never ob served. One difficulty of this approach, already discussed, is that it typically defines systemenvironment relations in tenns of dissipative energy transfer via an effective Ham iltonian i.e., it assimilates the logical fea tures of these relations entirely to the physical causal features. The impli cation is that if systems are sufficiently isolated from their environments,
decoherence can be delayed, or perhaps even prevented altogether. Re 0 cent experiments1 have shown, however, that even when system isola
tion is sufficient to negate any measurable energy transfer between sys· tern and environment, decoherence nevertheless persists. Thus, a number
e hav o decoherence possible environmental sources of n ndissipative of now been proposed including the notion that these sources are, in pnn1 1 ciple, unidentifiabl e because they are 'intrinsic' features of nature. •
LOGICAL CAUSALITY IN QUANTUM MECHANICS
1 53
The other central difficulty, also raised earlier, i s that the decomposi tion of the un iverse into 'system,' 'detector,'
and
' environment,' neces
sarily presupposed by the environmental decoherence approach, is itself conceptually problematic.12 On the one hand, quantum theory depicts this decomposition as purely arbitrary and therefore only i nstrumentally and epistem icaily significant. However, the process of environmental deco herence is one wherein this subjective, epistemic distinction has objec tive, ontological consequences; for different decompositions yield very · different obj ective measurement outcomes.
The decoherent histories approach, 13 by contrast, was devised to ob
viate the global decomposition problem by envisioning alternative poten tial measurement outcomes as alternative potential histories of the uni verse itself. Thus, rather than depicting a physical
decomposition
of a
global physicalextensive structure into physicalextensive substructures arbitrarily labeled ' system, ' 'detector,' and 'environment,' the decoher
ent histories approach depicts a logical decomposition of a global history into alternative potential subhistories that can be i ntegrated coherently
and consistently. In this way, quantum mechanical histories are no dif ferent than h i stories in the conventional sense; that is, despite the exist ence of finegrained incompatibilities among potential local subhistories constitutive of a shared global history, these can always be coarse
grain ed to the point at which they are mutually consistent and coherently
Integr able. Robert Griffiths, for example, defines the ' consistency condition ' for decoherent histories as the requirement that the probability val uation for each alternative coarsegrained history equal the sum of the •
proba bi lities of its constitutive finegrained h istories.1 4 S atisfaction of the consiste ncy condition is initially impeded by quantum interference am ong fi negrain ed histories, but appropriate coarsegraining effects a
.
I ogic ai negati mutually ve whereby chapter 3 . 1 ) selection (see process . Interfering finegrain ed histories are summed over v i a the trace function
�escribed earlier. Note that the presupposition of consi stent and coherent
Integration i s justi fied by the presupposition of a ' glob al history' i.e., s om e ' ultim ately' close d system (the universe itself being the only such syste m), whic h is a necessary presupposition of quantum m echa nics.
1 54
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This key advantage of the decoherent histories approach to quantum mechanics, however, is unfortunately also its key disadvantage; for as is the case with conventional histories of events, there are many possible coarsegrainings by which maximally finegrained histories of quantum events can be integrated coherently and consistently . Thus, in a quantum measurement interaction, when mutually exclusive and exhaustive prob ability outcomes are defined in tenns of mutually exclusive and exhaus tive alternative coarsegrained histories, there is no criterion by which certain consistent coarsegrainings are preferred over others that might be equally consistent. Even more problematic, one can easily define al ternative coarsegrained histories that are consistent (i.e., mutually exclu sive and exhaustive, satisfying PNC and PEM) yet nevertheless depict nonclassical sequences of events. These consistent yet "grotesque" his tories, to use Griffiths' terrn for them, 1 5 are alien to classical experience. Thus, the probability valuation of potential outcome states guaranteed by the consistency condition is, by itself, a necessary but insufficient criteri on for classically meaningful outcome states. In summary of the discussion thus far, the decoherent histories ap proach was intended to depict the evolution of classical physical relations from quantum mechanical relations in a manner that avoids the decom position problem inherent in the environmental decoherence approach i .e., a purely subjective partitioning of system, detector, and environment that nevertheless has objective, measurable consequences. This problem is avoided by denying altogether the quantum mechanical significance of any physical distinction between system and environment, instead reduc ing their relation to a purely mathematical integration in the form of con sistent global histories. But this sheer mathematization of relations, con ditioned by the consistency condition, though it does account for the classicality of probabilities in quantum mechanics (satisfaction of the sum rules, distributive law, PNC, PEM, etc. ), does not account for the classicality of the actual measurement outcomes generated by quantum mechanics. Likewise, the environmental decoherence approach attempts a similar reduction but in the opposite direction a reduction of the logt•
LOGICAL CAUSALITY IN QUANTUM MECHANICS
1 55
cal features of systemenvironment relations to purely physical dynamical features. As will be shown presently, the central deficiencies of both the decoherent histories and environmental decoherence approaches stem from their shared portrayal of the physicalcausal and mathematical logical aspects of decoherence as m utually exclusive, with their proper mode of relation being the sheer assimilation of one aspect to the other. By contrast, the relational realist approach, in emphasizing the m utually implicative relationship between the logical and physical aspects of quantum decoherence, is reflective of both the environmental decoher ence and decoherent histories approaches. For example, in emphasizing the ontological significance of local measurement contextuality, the rela tional realist approach does not dismiss the distinction of local system and global environment
as
purely epistemic. But at the same time, by
emphasizing that locally contextualized measurement interactions are always internally related to a global totality of dative facts, the relational realist approach likewise does not sheerly assimilate the global logical aspects of these relations to local efficient causal aspects
i.e., such that
it is only via energy exchange that these relations are understood to be physically relevant. Both of these emphases are together embodied by the compatibility condition for logical causality proposed herein (and formalized mathe matically in chapters 9 and 1 0), which can be viewed as a supplement to the consistency condition. As discussed in chapter 3 . 1 , in order to proper ly formalize systemenvironment relations such that the inadequacy of the consistency conditions is remedied, one must first address the fact that there is a structural difference between [a] the Boolean subalgebras
by which quantum observables are locally contextualized and [b] the par tial Boolean algebras by which the latter are globally related.
In other words, there is a difference between the algebraic structure of quantu m observables and the algebraic structure of macroscopic ob servables at coarsegrained scales, and this difference is ignored in the con sistent histories approach. But by augmenting the Griffiths consisten cy conditions with the compatibility condition introduced herein, one is
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able to sustain the concept of classical localglobal relations as emergent from quantum localglobal relations. Again, as will be further elaborated in part II, this is achieved via a sheaftheoretic mereotopological descrip tion of the localglobal relation of Boolean algebras . In this regard, the compatibility condition essentially depicts a transition morphism from one local Boolean context to another, generating asymmetrical logical and mereotopological revisions16 of equivalence classes of local contex tual Boolean algebras. Topologically, these revisions yield partial compatibility on their overlapping regions (e.g., partial Boolean compatibility of coarsegrained position and momentum observables, up to the limit of Heisenberg un certainty relations). This ' inductive limit,'17 by which local compatible fam ilies of Boolean algebras can be extended globally, is constructed via the formation of a set of equivalence classes of partially compatible Boolean subalgebras, representing partially compatible Boolean contex tualized observables, on all possible overlaps. The compatibility condi tion thus requires as a categorical presupposition that all local measure ment contexts are structurally Boolean, and that the asymmetrical Boolean structure of any local context is preserved when extended glob ally, via internal relation, to other contexts. The implementation of the compatibility condition in quantum measurement via this sheaftheoretic topological method, the rudiments of which will be introduced in chapter 5 as a propaedeutic to part II, al lows one to forn1ally depict, mereotopologically, this structure preserving extension of local Boolean contextuality globally. It is via this mereotopological depiction of decoherence that one can characterize classical observables as emergent from quantum observables in a manner that is ontologically consistent and coherent, and which requires no ad hoc additions to (or dispensations from) the standard quantum theory; it merely makes explicit use bf the same categorical logicaL presuppositions already present implicitly in the standard formalism, employing them in a novel, sheaf theoretic description of quantum measurement.
LOGICAL CAUSALITY IN QUANTUM MECHANICS
4.3
1 57
The E\'olution o f P otentiality to Prob ability
In the relational realist interpretation of quantum mechanics de scribed thus far, predicative facts I measurement outcome events are fun damentally quantum units of Iogicophysical internal relation. In the pro cess of actualization e.g., quantum mechanical state evolution the novel predicative fact I .measurement outcome in process (or in White headian tenns, the 'actual occasion' undergoing 'concrescence') is inter nally related to its dative world of actualized facts. With respect to the earli er discussion of the expression:
I'P)
=
a
l lf/ t) I¢ t) Je t) + fJ l lfli) I¢ 1) ! e J.)
by ' internal relation, ' it is meant that each datum constitutive of the global totality I'¥> is also internally constitutive of the quantum process by which the novel predicative fact l lf/ r) I ¢ t) je t) or l lf/ 1) I ¢ 1) le �,) is actualized. This process is fundamentally a logically conditioned integra tion of potential relations betvveen [a] the local propositional measure ment outcome I predicative fact, i.e., a l lf' r) I ¢ t) j e t) or f3 1 lf/ �,) I ¢ J) le !), internally related to [b] the global data constitutive of j'Y). This integra tion takes the forrn of an evolution from potential relations to probable relations in that the latter satisfy both PNC and PEM. This evolution is reflected in the reduction of the pure state to the mixed state in quantum mechanics. But as discussed in the previous section, an evolution of potential re lations to probable relations is only possible if one presupposes a local Boolean context for each of the relata i.e .., both [a] the actual occasion inprocess (the propositional predicative fact/measurement outcome) e .g., a l lf/ t) I ¢ t) le t) or fJ i lf/ .1) I ¢ �, ) le J ), where the selection of 'l ocal context' is detennined by the particular measuring apparatus 1 ¢ ) and de fined by its preferred orthonozInal basis in this case, I¢ t) + I ¢ J.); and [b] the individu al data constitutive of j'¥). And while a local Boolean context is pres uppo sed for each datum in /'¥) , quantum mechanics does not permit the construction of a 'global' Boolean context for !'¥) as a
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concatenation of all local contexts.1 8 This is well evinced in the quantum indeterrninacy relations, according to which a complete state specifica tion of 1'¥)i.e., a total order of its data is not possible. Quantum me chanics can, however, yield an inductively limited maximal specification by defining the global state 1'¥) as an overlap of equivalence classes of all compatible local Boolean contexts I subalgebras. This is the inductive limit described at the end of the previous section and which will be de scribed in more formal detail in part II. Most important, however, is that in quantum mechanics, the global data contextualized via this overlap can only be induced by reference to the local Boolean context (preferred orthonormal basis) of a particular measurement interaction. This local measurement context, though it is contained in the overlap, is 'indexical' in that it restricts the potential relations between [a] and [b] (above) to its preferred basis. Apart from this restriction, potential outcomes cannot evolve to become classically meaningful probable outcomes. Decoherence, as discussed earlier, refers to the outcome of a process whereby a coherent pure state of alternative potential outcomes is dis tilled into the 'decoherent' set of mutually exclusive and exhaustive probable outcomes characteristic of the mixed state. Quantum mechanics always describes the evolution of puretomixed state relative to a single, locally contextualized propositional measurement outcome I predicative fact an 'indexical eventuality' locally Boolean contextualized by the orthonormal basis of the detector. This indexical eventuality is, in the Whiteheadian I relational realist scheme, the actual occasion in process. The correlation of the measured system I ll' ) and the detector 1 ¢ ) with the unmeasured environment ·I e ) and its manifold degrees of freedom pre supposes a global logical structure by which the potential relations con stitutive of the expression /'I')
=
aijk
.......
i,j,k
l lfl) i I ¢ )j I e )k
s on relati can be integrated such that they evolve to become probable constitutive of the expression 1'¥) a I Cf/ i) I ¢ i) l e i) + f3 1 lfl t) I ¢ �.) l e .!)· =
LOGICAL CAUSALITY IN QUANTUM MECHANICS
159
Again, this global logical structure is defined in quantum m echanics as a maximal overlap or equivalence class of all local Boolean contexts indexed to the local Boolean context (preferred orthonormal basis) of some p articular indexical event
I actual occasioninprocess belonging to
1¢ ). But beyond the integration of local contexts, decoherence pertains to the integration of the dative content of these contexts
or more precise
ly, the i ntegration of the relations among these data, to which the indexi cal eventuality
I actual occasioninprocess is internally related. As dis
cussed earlier, the evolution of a coherent superposition of potential
outcome states, most of which are mutually logically inconsistent in terms of PNC, to a decoherent probability distribution of logically con sistent probable outcome states satisfying PNC and PEM is achieved by incorporating the unobserved facts of the measured system' s environ ment or alternatively, the manifold finegrained histories integrating these environmental facts with those of the measured system quantum
measurement
forrnalism.
Making
explicit
these
into the system
environm ent relations introduces manifold degrees of freedom into the superposition of potential outcome states, allowing for their integration into coarse grained equivalence classes, with each class indexed to a dif ferent potential outcome state (Whiteheadian 'subjective form ') of the indexi cal event I actual occ asio ninprocess.
With the imposition of the Boolean compatibility condition dis
cussed earlier, the magnitude of environmental degrees of freedom with
In each equivalence class produces a great deal of mathematical cancellation among potential systemdetectorenvironment outcome states that •
Interfere (i.e., that violate PNC) within each class. A traceover of the enVlro n mental degrees of freedom thus represents the elimination of these •
•
l ogically incoherent states represented by the offdiagonal tenns in the density matrix. The elimination of these tenns effects the reduction of the
pure state, with its interfering superposition of potential measurement outcome s, to the mixed state and its logically conditioned, decoherent matrix o fprobable o u t c o m e states. This crucial function of the environment in quantum mechanical measurement interactions has, for the most part, been ignored over the
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years, though its significance was alluded to even in the early days of the quantum theory. Recall the earlier quote from Heisenberg, who wrote that the superposition or interference of potentia, "which is the most characteristic phenomenon of quantum theory, is destroyed by the partly indefinable and irreversible interactions of the system with the measuring 19 apparatus and the rest of the world." Since quantum mechanics can be applied only to closed systems, any ontological interpretation of quantum mechanics must recognize the uni verse as the only truly closed system, such that as noted earlier, the de composition of I'P) into 'system' 'detector' and 'environment' subsys tems is purely arbitrary. Thus, the evolution of the state of any particular measured system is, in fact, the evolution of the state of the universe it self; and its evolution relative to a given indexical event, Boolean contextualized by a particular measuring apparatus, is merely its evolu tion relative to a particular fact belonging to itself. The paradoxes of self reference discussed in chapter 3 are avoided, as we saw earlier, by ac knowledging that every quantum mechanical predication is generative of a novel fact internally related to the global dative totality during the pro cess of actualization, and augmenting that totality once actualized. The correlation among facts belonging to 'system,' 'detector,' and 'environ ment, ' then, is easily comprehended by virtue of the fact that as the closed system of the universe evolves, so must all the relational struc tures subsumed by it, however they might be grouped and whatever they might be named. Quantum theorist Wojciech Zurek has described decoherence as a consequence of the universe's role as the only truly closed system, which guarantees the ineluctable 'openness' of every subsystem within it, and likewise the relational structure integrating the totality of these open sub systems. "This consequence of openness is crjtical in the interpretati on of quantum theory," Zurek continues, "but seems to have gone unnoticed for a long time. "20 By correlating system l lf/ ) and detector I ¢ ) with the environment I e ) and its manifold degrees of freedom, one thus gives an explicit representation of all potential internal relations inherent in anY particular measurement interaction.
LOGICAL CAUSALITY IN QUANTUM MECHANICS
161
For example, in the evolution of,
/'¥) to
J\}1)
=
=
aijk
i,j,k
l ¥t)i l¢)j le )k
a l ¥'t) l ¢ t) le t) + fJ i lfl J.) I ¢ J.) J e l)
those potential relations capable of logical integration, conditioned by the Boolean compatibility requirement discussed earlier, evolve to become decoherent,
m utually exclusive and
exhaustive, probable relations
{Whiteheadian 'valuated subj ective forn1s'):
These are represented in the density matrix as the following tern1s, re spectively:
l a 12 I ¥1 t>< ¥1 til¢ t>< ¢ t II e t>< e t l
Other potential relations are incapable of such integration without violating PNC. These are represented by the offdiagonal terms:
ci/3 l lf/ J)( lJI til¢ J..)( ¢ t II e J)( e tl The pote ntial relations represented by these tenns are eliminated fro m the integr ation via a negative selection process, mathematically ex pre ssed as a trace over of the unmeasured degrees of freedom supplied by the environment 1 :
CHAPTER 4
162
TrE !'¥)('¥!
= =
Li (ei I'I')('¥1 e; ) I a 12 l lfl t)( VI til ¢ i)( ¢ i I + LB 12 l lfl J.)( lJI 1l l ¢ t)( ¢ i I
Again, by the categorical imposition of the compatibility condition, this process of negative selection rests upon a fundamental presupposi tion of a global logical structure by which nonlocal potential relations among system, detector, and environment can be integrated into probable relations. But this global logical structure can only be defined in terms of local Boolean contexts and their associated Boolean subalgebras, such that a properly forrned internal relational structure of overlapping equiva lence classes of these contexts/subalgebras can be employed to represent an inductive approximation of the globaL During the process of the actualization of a measurement outcome, the dative content of this approximation that is, the potential relations constitutive of the expression:
is thus essentially coarsegrained by this Boolean localization scheme. Whitehead describes a very similar negativeselection mechanism in the process of concrescence a mechanism he ter1ned 'transmutation,' wherein potential relations incompatible for integration into a logically coherent and consistent history ('nexus') are eliminated via a massive average objectification of a nexus, while eliminating the de tailed diversities of the various members of the nexus in question. This method, in fact, employs the device of blocking out unwelcome detail . It depends on the fundamental truth that objectification is abstraction. It utilizes this abstraction inherent in objectification so as to dismiss the thwarting elements of a nexus into negative prehensions. This mode of solution requires the intervention of mentality [i.e., activi ty of the logicoconceptual pole of concrescence not conscious or an thropic mentality] operating in accordance with the Category of Trans...
LOGICAL CAUSALITY IN QUANTUM MECHANICS
1 63
mutation. It ignores diversity of detail by overwhelming the nexus by means of some congenial uniformity which pervades it.
The
environ
ment may then change indefmitely so far as concerns the ignored de tails
so long
as
they can be ignored?2
This 'massive average objectification' is possible logico mathematically for the same reason it is possible conceptually in White head's scheme; it is prefaced by an explicit integration o f the totality of potential relations between [a] the propositional measurement outcome I predicative fact internally related to [b] the data constitutive of !'¥). And this evolution of potential relations to probable relations is only possible if one presupposes a global logical order by which a Boolean localization scheme can be constructed. Whitehead writes: The irrelevant multiplicity of detail is eliminated, and emphasis is laid on the elements of systematic order in the actual
world
.
. . 23 In this
process, the negative prehensions which effect the elimination are not merely negligible . . . The actual cannot be reduced to mere m atter of fact in divorc e from the potential.24 Unless
some systematic scheme of relatedness
characterizes the envi
ronment, there will be nothing left whereby to constitute vivid prehen sion of the world. 25 Transmutation is the way in which the actual world
is felt as a community, and is so felt in virtue of its prevalent order.26
4.4
Quantum Events as Dipolar Units of Relation : Their Subjective and Obj ective Features Are Mutually Implicative
the same way that the preferred orthononnal measurement basis I Boo lean context of a detector is understood as constitutive of the detec In
tor,
the local context of the Whiteheadian actual occasion is understood as constitutive of the actual occasion. In this way the indexical context I 'subjective standpoint' of the actual occasioninprocess is 'self
1 64
CHAPTER 4
determined.' This seems an odd notion when applied to a classical con ception of 'detector' since the latter is obviously chosen by the experi menter. But if the detector is conceived ontologically as a quantum sys tem itself, as suggested by von Neumann, it can only be understood as a serial route or history of actualizations a socalled 'Von Neumann chain' tertninating, he proposed, in the mind of the experimenter. But if the mind is likewise describable quantum mechanically {at least to some degree, as it must be in any coherent ontological interpretation of quan tum mechanics) then the detectormind system for any given experiment is likewise properly understood as constitutive of a global system,
As such, the ' choice' of any particular measurement context for any particular actual occasion in the global system cannot simply be derived in the classical sense of an experimenter choosing a particular device. The most one can say is that every quantum actual occasion has its own particular local context, which is constitutive of itself. Indeed, to the ex tent that quantum mechanical predication is generative of novel facts, and thus novel totalities (i.e., with every novel fact, a novel j'l') ), it n1ust also be seen as generative of novel local contexts. The problem of self reference with respect to predication of a totality will likewise rear its head if one attempts to simply derive a particular local measurement con.. text from some other local context. This 'selfdetermination' of an actual occasion's subjective stand.. . sics metaphy I point local context is a signature feature of Whiteheadian But it is also the case in both Whiteheadian metaphysics and quantum mechanics that the local measurement context of a novel actual occasion.. inprocess, though not externally determined, is nevertheless internal�Y conditioned by virtue of its internal relatedness to its dative world. In quantum mechanics, this is evinced by the fact that the presupposed global logical structure is defined by a Boolean localization scheme,
LOGICAL CAUSALITY IN QUANTUM MECHANICS
165
where compatible local Boolean contexts overlap, and the indexical local measurement context must b e part of this overlap.27 In other words, po tential relations among the data of
I ljl;,
1 ¢), · and
je),
v i a their individual
local contexts, presuppose a partial compatibility among these local con texts in the expression
I'I')
= a
l lfl t)
I ¢ t)
je t) + f3 l lf/ J) I ¢ .t) je .J,).
This
internal relational compatibility can be expressed mereotopologically as a covering system of local Boolean algebras, heuristically representable
in classical topology as a localization system of open covers, for exam
ple, where each open cover represents a local Boolean context?8 Though the local indexical measurement context (i.e., the particular orthonotmal measurement basis of the detector) cannot simply be derived from the Boolean overlap, it m ust be compatible with this overlap
i .e., compati
ble for integration with the scheme of local contexts constitutive of the induced global context. Once actualized, the quantum actual occasion thus becomes a novel datum constitutive of a novel global totality, with its local context inte grated into the internalrelational, mereotopological B o olean covering scheme. Whitehead writes: The atomic actualities individually express the gen eti c un ity of the uni
verse. The world expands through recurrent unifications of itself, each,
by the addition of itself, automatically recreating the multiplicity anew. 29
In this way, every quantum actual occasioninprocess is both [a] subj e ctive in that its local context,
ternally conditioned by
internally selfdetermined,
is also
in
the global facts to which it is internally related;
and [b] objective in its actualization as a datum that is logically relatable to subsequent quantum occasionsinprocess internally related to it (i.e.,
subsequent measurement interactions). As noted in chapter 2. 8, and as
will b e discussed further i n chapter
5 , 'subsequent' here does not neces
sarily mean 'temporally subsequent,' but rather logically subsequent in the m ereot opological hierarchy of internal relations. It will b e argued that any metri cal, spatiotempo ral expression of subsequence i s a specialized
CHAPTER 4
1 66
case of, and dependent upon, a more fundamental mereotopological ex pression of logical subsequence. For any ontological interpretation of quantum mechanics, then, [a] and [b] above are evinced by the fact that any measurement outcome must itself be measured
i.e., 'related' as a
datum to a subsequent actual occasioninprocess. Of the subjective aspect of quantum actual occasions, Whitehead writes: An entity is actual when it has significance for itself. By this it is meant that an actual entity functions in respect to its own determination . . . It is selfcreative; and in its process of creation transforms its diversity of
roles into one coherent role . . . This selffunctioning is the real internal constitution of an actual entity. An actual entity is called the 'subject' of its own immediacy. 30
An actual entity, by functioning in respect to itself, plays diverse roles
in selfformation without losing its selfidentity. It is selfcreative; and
in its process of creation transforn1s its diversity of roles into one co
herent role. Thus 'becoming' is the transfonnation of incoherence into coherence, and in each particular instance ceases with this attainment.31
Of the objective features of the actual occasion, and its function in relation to the systematic totality of occasions constitutive of its dative world (i.e., !'¥)), Whitehead writes: to ' function' means to contribute detennination to the actual entities in the nexus of some actual world. Thus the determinateness and self identity of one entity cannot be abstracted from the community of di verse functionings of all entities. 32 The real potentialities relative to all standpoints are coordinated as di verse determinations of one extensive continuum. This extensive con
tinuum is one relational complex in which all potential objectifications fmd their niche . . . All actual entities are related according to the de ... tern1inations of this continuum; and all possible actual entities in the fu ture must exemplify these determinations in their relations within an al ready actual world. 33
LOGICAL CAUSALITY IN QUANTUM MECHANICS
1 67
In quantum mechanics, as in Whiteheadian metaphysics, quantum actual occasions are irrelevant to the world apart from their relational function as data (i.e., the 'facts of the world' ) in a subsequent actualiza tion
I concrescence. For Whitehead, the actualization of an actual occa
sionin�process (its 'satisfaction') entails "the notion of the 'entity as .
concrete' abstracted from the 'process of concrescence' ; it i s the outcome separated fro m the process, thereby losing the [dipolar] actuality of the 34 atomic entity, which is both process and outcome." Thus, the probabil ity valuations of quantum mechanics describe probabilities that a given potential outcome state will be actual
implying a sub
upon evaluation
sequent evolution and an intenninable evolution of such evolutions. Eve
1)' fact or system of facts in quantum mechanics, then, subsumes and im
initial state ofpotential relations with its dative world, and afinal state of actual relations with its dative world via its incorporation, plies both an
I predicative fact, into that world. In other words, there can be no state specification of a system S without reference, implicit or explicit, to S initial and S final· This is reflected in Whitehead's scheme by as novel datum
referring to the quantum actual occasioninprocess as the 'subj ect superject,' where both subj ective and objective features are mutually im plicative aspects of every quantum occasion. The 'satisfaction' is the 'superject' rather than the 'substance' or the ' subject.' It closes up the entity; and yet is the superject adding its
character to the creativity whereby there is a becoming of entities su 35 perseding the one in question. An actual entity is to be conceived as both a subj ect presiding over its own immediacy of becoming, and a superject which is the atomic crea 36 ture exercising its function of obj ective immortality It is a subject •
•
.
sup erject, and neither half of this description can for a moment be lost 7 f sight o [The superject is that which] adds a determinate condition to the settlement for the future beyond itself.38 .
.
•
Thus, the process of the actualization of a quantum m easurement outco methe evolution of potential relations to probab le relations via
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decoherence is never terminated by actualization, but only punctuated by it. The many facts constitutive of 1'¥) and their associated potential relations to the actual occasioninprocess, become one novel predicative fact a predication of the global totality and are thus increased, histori cally, by one. "The oneness of the universe, and the oneness of each ele ment in the universe, repeat themselves to the crack of doom in the crea tive advance from creature to creature, each creature including in itself the whole of history and exemplifying the selfidentity of things and their 39 mutual diversities."
4.5
Quantum Mechanics Presupposes Logically Related Actual O ccasions
In both the decoherencebased interpretations of quantum mechanics and the relational realist philosophical cosmology, with its foundations in Whiteheadian metaphysics, the world is characterized not as a fixed to tality, b ut rather as a global mereotopological process generative of in ternally related and logically structured facts. Both attempt to describe the relational forrns of these presupposed facts; they do not attempt to explain the existence of these facts as in other interpretations of quantum mechanics e.g., the various quantum cosmologies discussed in chapter 2, as well as those interpretations of quantum mechanics that posit a physical dynamical mechanism (stochastic field fluctuations, etc.) as 40 'causative' of wave packet collapse to a unique actual state. In other words, neither the decoherencebased interpretations nor the relation al realist cosmology proposes a mechanism that ' accounts for' the existence of quantum events, the 'objective facts' of reality. Unlike other ontologt.. cal interpretations of quantum mechanics that consider this a deficien cy or a problem to be solved, the decoherencebased interpretations, wh eth.. er implicitly or explicitly, acknowledge that facts are necessarily pres upsci the by posed by quantum mechanics and indeed as argued earlier entific method in general. Focus is instead placed upon the forms of •
•
LOGICAL CAUSALITY IN QUANTUM MECHANICS
1 69
relations among quantum events the logically conditioned evolution of potential relations to probable relations and the conception of novel quantum events as predicative facts generated by these relations. Beyond the necessary presupposition of facts in quantum mechanics, then, the decoherencebased interpretations of quantum mechanics and the relational realist philosophy rest upon an equally fundamental pre supposition of relation among facts. In the same way that the concept of relation necessarily presupposes object relata (even when these objects are, themselves, relations), it is also the case that in quantum mechanics, the fundamental objectsquantum events as res vera or 'final real things' presuppose relation as a generative process. Furtherinore, as will be explored in the next chapter, although the quantum actual occasions themselves are discrete, their potential rela tions are continuous and therefore metrically describable in tenns of their extensive features. Thus, in the same Aristotelian sense that potentia al ways presuppose actualities, the continuous metrical descriptions of ex tension deriving from these potential relations presuppose a discrete, mereotopological extensive order of actual facts. But at the same time, in the relational realist philosophical scheme it is also true that actualities ahvays presuppose potentia, since potential relations are always genera tive of novel actualities viz., the quantum mechanical evolution of po tential fact to probab le fact to novel actual fact In this regard, the various attempts by the physical sciences to depict physical reality as either fun dam entally discrete or fundamentally continuous (reflected, for example, by the tension between quantum mechanics and general relativity) ne glect the fact that quantum actual occasions cannot be abstracted from, or even defined without reference to, their actual and potential relations, both logical I mereotopological and extensive I metrical. Potentiality and actuality are thus mutually implicative in the rela tional realist philosophy, whose fundamental objects are quantum me chan ical units of Iogicophysical relation rather tha:n simply units of . h P. YSi cai relata. Objects are therefore always understood as relata, and likewi se relatio ns are always understood obje ct iv ely .
CHAPTER 4
1 70
4.6
Summary
Both the decoherencebased ontological interpretations of quantum mechanics and the relational realist philosophical cosmology, the latter with its roots in Whiteheadian philosophy, describe a relational process productive of predicative quantum actual occasions I measurement out comes in three stages: [ 1 ] An initial phase consisting of the potentialization of the global totality of facts !'!') relative to a particular, indexical potential quantum measurement outcome I quantum actualizationinprocess. In terms of the standard quantum forrnalism, this phase is represented by the expresSlOn: •
where I¢ ) represents the state of the detector according to its particular local Boolean contextualization, defined by its particular orthonorrnal measurement basis, and / If' ) and I e ) represent the state of the measured system and environment, respectively, relative to the particular contextu alization given in I¢ ) . Onto logically, this expression represents the internal relation of the indexical actualizationinprocess to the dative global totality i.e., the global lattice of quantum events conditioned by presupposed logical first principles: the Principle of Identity (PI), the Principle of Non Contradiction (PNC), the Principle of the Excluded Middle (PEM), and the Boolean relational forms of conjunction, disjunction, implication, complement, and exclusive disjunction by which PI, PNC, and PEM are defined. These requirements are satisfied via the presupposition of a Boolean compatibility condition and localization scheme, by which the underly ing, implicit Boolean structure of the global pure state !'¥)i.e., impl icit in virtue of the presupposition that each and every one of its constituent
LOGICAL CAUSALITY IN QUANTUM MECHANICS
171
local contexts is Boolean and thus representable as a Boolean subalge bra is rendered
explicit
via its definition as an ov·erlap of compatible
local Boolean contexts, expressible as an equivalence class of Boolean subalgebras. Potential internal relations of the quantum actual occasion
I
measurement eventinprocess to the dative content of these overlapping local contexts are always indexed to the local context (Boolean subalge bra) of the fanner
i.e., such that it is understood as an indexical event,
which in quantum mechanics is always associated with the detector. Thus, a quantum actual occasioninprocess entails the evaluation of a general Boolean algebra to a twovalued (T,F) Boolean algebra that is defined by the locally contextualized indexical quantum event, classical ly represented by the detector. This is exemplified in the conventional Hilbert space fonnalism by its requirement of an orthononnal measure ment basis by which the local indexical B oolean context is defined, and the fact that quantum mechanical measurement outcomes are 1 4 tualized as contextualized by this basis. [2]
A szpplementary phase,
always
ac
whereby the coherent superposition of
potential internal relations among the data contextualized by this Boole an localization scheme are integrated into equivalence classes, each class indexed to a potential outcome state defined by the local Boolean context of the actual occasion
I measurement eventinprocess. In the spin Yz sys
tem discussed earlier, this is reflected in the expression:
1'¥) = a I {jl t> I ¢ t> I e t> + /3 1 {jl �,> I¢ 1> Ie t> Thus, in the supplementary phase, global potential internal relations
in the initial phase are restricted by the local indexical context; but at the same time, the local indexical context is necessarily contained within the overlap of ail compatible Boolean contexts constitutive of the global to tality. Potential internal relations incapable of integration within this Boolean logical structure (those that violate PNC) are eliminated via neg ative selection. This is represented in the decoherencebased interpre
tations of quantum mechanics as a traceover of environmental degrees of freedom and elimination of offdiagonal tenns in the density matrix. The
CHAPTER 4
1 72
result is a decoherent reduced density matrix of mutually exclusive and exhaustive, logical integrations of potential internal relations
i.e., a re
duced matrix p r of probable predicative facts I measurement outcomes.42 TrE 1'¥>�1
= =
Li (ei !'l')(l¥1 e; )
I a 12 I {jl t>< lfl t II ¢ t>< ¢ t I + 1/J 12 I {jl .�>< VI .!II ¢ .J>< ¢ J. l
[3] The presupposed and anticipated actualization of one of these predicative facts I measurement outcomes I a 12 I T.fl t)( {jl ti l ¢ t)( ¢ t I or 1/3 12 l lf/ .!)( ljl J.ll ¢ L)( ¢ 1 l according to the probability valuations a and fJ qualifying each. This anticipated actualization reflects a presupposition
of PNC and PEM, justified by the fact that as probability valuations,
! a 12 + 1,8 12 = 1 . By PEM, at least one outcome must be actualized. And by PNC, at most one outcome must be actualized. In the most general terms, then, these three stages together depict fundamental substance as quantum 'becomings' (Whiteheadian 'actual occasions') whose actualization ('concrescence') is predicative via inter nal relations with ('prehensions' of) a totality of antecedently settled be comings
i.e., 'concrete facts'
the global data of the settled world. In
ternal relations to these data, as a totality, are perpetually repotentialized with each novel quantum actual occasioninprocess and its internal rela tion to that totality. These relations are both causalphysical and logicalconceptual in that their causalphysical features are logically integrated or ' objectified' in the evolution from potentiality to probability; thus each novel quantum predicative fact when considered as a substantial 'thing initself is fun damentally a discrete unit of relational evolution
from the facts of I'¥)
to potential internal relations to j'P), to probable internal relations to 1\f), to concrete actual internal relation to j'P), and thereby inclusion within it as a novel fact constitutive of a novel totality. The internal relations inte grated in this evolution are thus both physically and logically significant, such that every quantum actual occasion I predicative fact is properly
understood as dipolar; that is, its physical and logical features, as well its objective (i.e., dative) and subjective (i.e., contextual) features,
as
are
LOGICAL CAUSALITY IN QUANTUM MECHANICS
173
understood as mutually implicative aspects of every quantum actual oc casion I predicative fact. The relational realist scheme of internal relation among dipolar quan tum actual occasions thus reflects a correlation of the order of logical implication and the order of causal relation what Whitehead terms, re spectively, the 'genetic division' and the 'coordinate division' of the pre dicative fact I actual occasion. The history of modern physics has re vealed with abundant clarity that the proper relation of the casual and logical orders as mutually implicative is crucial to the coherent integra tion of fundamental physical theories and their associated models e.g., quantum theory, relativity theory, the standard cosmological model, etc. For example, it is by the physicological dipolarity of a quantum actual occasion's internal relation to its dative world that the inability to causal ly order spacelike separated occasions per the restrictions of relativity theory i.e., in terms of a total orderdoes not in any way imply that spacelike separated occasions likewise lack a logical order. In relativity theory, for example, this notion of a logical order is clearly evinced in the partial ordering among events constitutive of individual spacetime intervals. The challenge of reconciling quantum theory and general rela tivity is deeply rooted in this issue, and after nearly a century of investi gation, a satisfactory integration has yet to be realized. To this end, the relational realist ontological interpretation of quantum mechanics sug gests an alternative pathway fon.vard that is grounded in the mutual im plication of logic and causality, providing both a conceptual philosophi cal and fonnal mathematical framework that elucidates how individual, local partial orders, defined on a continuum, are connectible logically and physically within a unified hierarchy of discrete, internally related, predicative facts, each bijectively related to its global totality in the hier archy.43
1 74
CHAPTER 4
Notes 1.
Alfred North Whitehead, Process and Reality: An Essay in Cosmology.,
Corrected Edition, ed . D. Griffin and D. Sherburne (New York: Free Press, 1 978), 28393 . S . Walborn et al . , "Doubleslit Quantum Eraser," Physical Review A 65, no. 3 (2002): 0338 1 8 . 2. 3.
See, for example: Patrick B arry, "What's done is done . " New Scien .
.
tist 1 9 1 , no. 257 1 (2006): 36 . 4.
.
See, for example: Daniel Sheehan., ed., Frontiers of Time: Retrocausa
tion  Experiment and Theory (Proceedings of the Pacific Division of the Amer ican Association for the Advancement of S cience, American Institute of Physics, San Diego, California, June 2022, 2006). 5.
Correlated S and P detection events are registered via a coincidence
counter 1 inking both S and P detectors
the same method of correlating detec
tion events at the separate detectors in a typical EPR experiment. 6.
Introduced in chapter 2 . 1 .
7.
Simon Kochen and Ernst Specker, "The Problem of Hidden V ariables
in Quantum Mechanics," Journal of Mathematics and Mechanics 1 7 ( 1 967): 59 87 . 8.
For an introduction to algebraic topology and sheaf theory, see:
David Eisenbud, Com1nutative Algebra: With a View Toward Algebraic GeoJne
try. Vol. 1 5 0 (New York: Springer, 1 995); Sergei Gelfand and Yuri Manin, Methods of Homological A lgebra, 2nd edition (New York: Springer, 2003); Saunders MacLane and Ieke Moerdijk, Sheaves in Geometry and Logic: A First
Introduction to Topos Theory (New York: Springer, 1 992); Saunders MacLane, Categories for the Working Mathematician (Graduate Texts in Mathematics), 2nd ed . (New York: Springer, 1 998) . 9.
See, for example:
Wojciech Zurek, "Decoherence, Einselection, and
the Quantum Origins of the Classical," Reviews of Modern Physics 75, no. 3 (2003): 7 1 575. See also: Maximilian Schlosshauer, "Decoherence, the Me as urement Problem, and Interpretations of Quantum Mechanics," Review s of Mod
ern Physics 76, no. 4 (2005): 1 267; and Maximil ian Schlosshauer, Decohe rence and the QuantumtoClassical Transition (New York: Springer, 2007).
1 0 . S . Bertaina et aL, ''Quantum oscillations in a molecular magnet," Na
ture 453 (May 2008): 2036; S . Takahashi et al . , "Decoherence in Crystals of Quantum Molecular Magnets," Nature 476 (July, 20 1 1 ) : 7679.
LOGICAL C AUSALITY IN QUANTUM :MECHANICS I I.
1 75
Pritiraj Mohanty, E. M. Q. J ari wal a, and R. A. Webb, "Intrinsic Deco
herence in Mesoscopic Systems," Physical Review Letters 78, no. 1 7 ( 1 997):
3366; P.C.E. Stamp, ''The Decoherence Puzzle," Studies in History and Ph ilos
ophy of Modern Physics 37 (2006): 490. 1 2 . See, for example: O limpia Lombardi, S . Fortin, and M. Castagnino, "T he Problem of Identifying the System and the Environment in the Phenome non of Decoherence," The European Philosophy of Science Association Pro
ceedings: Antsterdam 2009, ed. H. W. de Regt, S . Hartmann, and S. Okasha (Berlin: Springer, 20 1 2), 1 6 174; Wojciech H. Zurek, "Decoherence, Einselec
tion and· the Existential Interpretation (the Rough Guide)," Philosophical Trans
actions of the Royal Society A: Mathematical, Physical and Engineering Scienc es 356, no. 1 743 ( 1 998): 1 820. 1 3 . See, for example: Robert Griffiths, "Consistent Histories and the Inter pretation of Quantum Mechanics," Journal of Statistical Physics 36, no. 1 ( 1984): 2 1 972; Roland Omnes., "Logical Reformulation of Quantum Mechanics I. IV;'' Journal of Statistical Physics 53, nos . 34 ( 1 988): 893957; Murray Gell Mann and James Hartle, ''Quantum Mechanics in the Light of Quantum Cos mology," Proceedings of the 3rd International Symposium on the Foundations
of Quantum Mechanics in the Light of New Technology, Tokyo, Japan (August 1 989): 32 1 43 . I 4 . Robert Griffiths, "Consistent Histories and the Interpretation of Quan tum Mechanics," Journal of Statistical Physics 36, no . 1 ( 1 984): 2 1 972.
1 5 . Griffiths, "Consistent Histories and the Interpretation of Quantum Me
chanics,"' 233 .
1 6 . See chapter 3 . II.
1 7. Introduced i n chapters 2 and 3 and formalized mathematically in part 1 8 . As discussed in chapter 2, per the KochenSpecker Theorem, the partial
Boolean algebra of projection operators characteristic of quantum mechanics cannot, in general, be embedded into a Bool ean algebra. .
1 9 . Werner Heisenberg,
Physics and Philosophy (New York: Harper
Torchbooks, 1 9 5 8 ) , 1 43 .
20. Wojciech Zurek, "Letters," Physics Today 46, no. 4 ( 1 993): 84. 2 1 . Zurek, "Decoherence and the Transition from the Quantum to the ClasSical," 3644 . •
2 2. Whitehead, Process and Reality, 1 0 1 .
1 76
CHAPTER 4
23. Whitehead, Process and Reality, 254. 24. Whitehead, Process and Reality, 22627. 25. Whitehead, Process and Reality, 254. 26. Whitehead, Process and Reality, 25 1 . 27. Elias Zafiris, "Boolean Coverings of Quantum Observable Structure: A Setting for an Abstract Differential Geometric Mechanism," Journal of GeoJne
try and Physics 50, no. 99 (2004). 28. This classical topological covering scheme is heuristic representation only. A proper mathematical representation in terms of Grothendieck topology wil l be discussed in detail in part II of this volume. 29. Whitehead, Process and Reality, 286. 30. Whitehead, Process and Reality, 25. 3 1 . Whitehead, Process and Reality, 25. 32. Whitehead, Process and Reality, 25. 33. Whitehead, Process and Reality, 66 (italics added). 34 Whitehead, Process and Reality, 84. .
35. Whitehead, Process and Reality, 84. 36. Whitehead, Process and Reality., 45. 37. Whitehead, Process and Reality, 29. 3 8 . Whitehead, Process and Reality, 1 50. 39. Whitehead, Process and Reality, 228 . .
40. For example, the Spontaneous Localization theory of Ghirardi, Rimini, and Weber. See, for example: G. C. Ghirardi, A. Rimini, and T. Weber, "Unified dynamics for microscopic and macroscopic systems," Physical Review D 34 ( 1 986): 4709 1 , and G. C . Ghirardi, Sneaking a Look at God's Cards: Unravel
ing the Mysteries of Quantum Mechanics (Princeton: Princeton University Press, 2004), 406. 4 1 . As discussed earlier, the conventional Copenhagen interpretation with
its Hilbert space formalism gives no reason why this should be so.
42. Zurek, "Decoherence and the Transition from the Quantum to the Clas sical," 39. 43. See chapter 1 1 .6; see also: A. Mallios and E. Zafiris, "The Homologi cal KahlerDe Rham Differential Mechanism Part I: Application in the General Theory of Relativity," Advances in Mathematical Physics, 20 1 1
(201 1 ),
doi: I 0. 1 155/20 1 1 / 1 9 1 083, and A. Mal lios and E. Zafiris, "The Homolog ical Kahl erde Rham Differential Mechanism Part II: S heafTheoretic Localization
LOGICAL CAUSALITY IN QUANTUM 1v1ECHANICS of Quantum Dynamics," doi: I 0.1
1 55/20 1 1 / 1 8980 1 .
1 77
Advances in Mathe1natical Physics, 20 1 1 (20 1 1 ),
CHAPTER S
Integrating Logical Relation and Extensive Relation : Mereotopology and Quantum Mechanics
The · internal relational framework by which the discrete, logical, 'genet ic' relations among quantum events are correlated with their continuous physical 'coordinate' relations is presented by Whitehead in part IV of Process and Reality: It is his mereotopological scheme of 'extensive connection,' whose fundamental features are the relations among locally defined actual occasions and their internally related global regions. In earlier works, this was a settheoretic mereological scheme, whose fun damenta] units were 'extensive wholes' and 'extensive parts' rather than the internal relation morphisms connecting actual occasions to their re gions, and their regions to other regions via internal relation to the global totality. "This defect of startingpoint," wrote Whitehead, "revenged it self in the fact that the 'method of extensive abstraction' developed in those works was unable to define a 'point' without the intervention of the 1 theory of 'duration. "' His earlier works, in other words, .defined 'point' as the discretization of an 'actual' continuum. But defining a point as an extensive element of the continuous real line implies that the point, too, must be continuously divisible extensively (i.e., in tenns of its coordinate analysis); thus the actual occasion, when represented coordinately as a point, loses its quantum character.
CHAPTERs
180
By contrast, Whitehead's later ar
.
gum ent m Process and Reality is more firmly anchored to his comm itrn �nt to the Aristotelian notion of "infinitum actu non datur": There is n 8
relational realist scheme, for exampl e
er
metrical abstraction derived from t hese
.
potential relations are infinite on tol o tential relation y ie ld s a novel actual
among actual occasions. In the
iy Understood as a higher order,
.
.
und erly1ng dtscrete relations. The . that the actualization of any po
e e l number line, a finite eprer � a
sentation of the infinite, wherein the t otahty . . 1mphes augmentation by either infini te e
.
Likewise, recall the mathematical
0f
. reIat1ons among numbers . . or Interpolation. xtr apo1 ation
e set of real numbers a contin . uum an d thus uncountable), Q (the set of r atwnaI numbers discrete and th us countable), and 7l (the set of inte e s u g r .also discrete and countable).
classical intuition, we SUali Y take the 'foundational' set to . . . . be the continuum �; and in extending t his rnath emat1cal Intuition to na. . tu re more broadly, w e likewise cons·Ide an '
According to
.
r
fundamental sp at io temporal background . twns, including quantum events, mi ht
g
extensive continuum' as a
. g a amst wh.tch all physical rela
g rep resentative of such relations

A
Universality and Equivalence
The definition of a category of algebraic objects of some kind with arrows being homomorphisms (structurepreserving morphisms) between them may be thought as an abstraction of the behavior of functions closed under the associative operation of composition. More precisely, the notion of a function is generalized to the notion of a homomorphism, whereas the associative operation of composition becomes an operation on sets of homomorphisms between algebraic objects of the same kind satisfying the same properties that functions and compositions satisfy. Notice that the composition of two functions/and g, denoted as f o g , is defined only in the case that the codomain of g is the domain of f Moreover, the composition of a function f with the identity of either its doma in or codomain gives/again. In a nutshell, the notion of a category of algebraic objects of some kind is a conception based on the behavior offunctions closed under the associative operation of composition, abstracted in terms of homomorphisms, which in turn, have been idealized as algebraic 'generalized elements' (or their duals) determining completely the algebraic obj ects themselves. Because there exists an obvious duality between incoming and outgoing homomorphisms with respect to an algebraic object, this is built into the definition of a category so that the
228
CHAPTER 6
operation of arrow reversal leaves invariant the concept of a category, meaning that this operation gives again a category being in dual or opposite relation in comparison to the given one. A consequence of this fact is that all categorical constructions come in dual pairs corresponding to the dual viewpoints of considering incoming or outgoing arrows with 1 1 respect to a constituted algebraic object. The foundational significance of category theory for our purposes stems from the fact that it provides a precise mathematical framework to express the basic Whiteheadian structure of the relational realist philosophical scheme. In particular, the two most fundamental concepts epitomizing the· philosophical function of the categorical framework in relation to our objectives are the concepts of universality and
equivalence. More concretely, category theory provides a framework of identification of universals in mathematical terms that is, the instances of a property which exemplify the property in such a paradigmatic way that all other instances have this property by virtue of factorizing uniquely through the corresponding universal. In this sense, objects are specified categorically via some universality property and only up to equivalence (canonical isomorphism). The universal for a property represents the essential characteristic of a property in the abstractive interpretational sense of the Aristotelian aphairein. For example, the categorical notion of the inductive limit is a universal, viz., it is characterized by a universal mapping property, which depicts it uniquely up to equivalence. It is instructive to think about the categorical notion of inductive limit as a universal process which exemplifies algebraically Whitehead's method of extensive abstraction. We note that the essence of the latter was its forn1ulation of a mathematical procedure by which the approximation to an ideal limit is consistently achieved depending on the properties of the relation of extension. The precise tenn coined by Whitehead in order to describe universals of this categorical nature is "eternal object" or "pure potential for the specific determination of fact.'' An eternal object is always a potentiality for actual entities, and thus has a metaphysical status whi ch is distinct from actuality, although it cannot exist separately from it. In
NOTION OF LOCALIZATION PROCESSES
229
particular, each eternal object I pure potential is characterized by its mode of ingression into some concrete actual occasion. Thus its functioning as a potentiality for actuality reveals its relational essence. Following Whitehead's description: A member of this species can only function relationally: by a necessity
of its nature it is . introducing one actuality, or nexus, into the real internal constitution of another actual entity. Its sole avocation is to be
an
agent in objectification. It can never be an element in the
definiteness of a subjective fonn. The solidarity of the world rests upon 12 the incurable objectivity of this species of eternal obj ects.
The crucial semantic convergence between the categorytheoretic notion of a universal with Whitehead's notion of an eternal object comes from the realization that both of them act as agents in the objectification of a multiplicity of actual occasions as a unified relational structure. For Whitehead, this is a categorical feature of relations among actual occasions, referred to as 'transmutation. ' 1 3 In categorytheoretic terms the operation of the category of transmutation is subsumed by the action of pairs of adjoint functors forming adjunctions. This is the case because all categorical universals may be thought of as defined up to canonical isomorphism by the existence of pairs of adjointfunctors between appropriate categories. In a welldefined sense adjoint functors should be understood as generalized conceptual inverses to each other. For example, the conceptual inverse of an 'extension functor' from one algebraic category to another i s called a 'restriction functor' pointing in the inverse direction. Likewise, an adj unction between two categories gives rise to a family of universal morphisms, one for each object in the first category and one for each object in the second. In this way, each object in the first category induces a certain property in the second category· and the universal morphism carries the object to the universal for that property; that is, it transmutes it to an agent of objectification in the second category exemplifying this
CHAPTER 6
230
property in a paradigmatic way. Every adjunction extends to an adjoint equivalence of certain subcategories of the initially correlated categories. In general, the equivalence of two categories � and Ql is defmed as
follows: An equivalence of two categories 1) and 2t. is defined by means
of a pair of opposite directing functors; F : 1) � 2( , G : 2t � i1 and a pair of natural isomorphisms; r : 1 1) � G F , p : 1 m � F o G where r o
is a natural isomorphism of the identityfunctor on � , and p is a natural isomorphism of the identity functor on 2l . In this case, the functorial
pro_c ess F : 1) 7 2l is called strictly inverse to the functorial process
G : 2( 7 1) If the pair of opposite directing functors is adjoint, then the 
.
equivalence is called an adjoint equivalence. The notion of equivalence of categories thus transcribes the general concept of congruence in a categorical/functorial context. Now we make the observation that given any category 2l , the
morphisms in 2£ , or equivalently the morphisms in
2l op
, can be defined
as the elements in the values of the Hom 21  bifunctor:
Hom 21 ( , ) = y �:? 
from the product category because 2( and
2l op

2!. op
x
= 2top X 2l 7 Sets
ill
to the category of sets. This is
are considered to have the same objects and
reversed morphisms. The Hom21 bifunctor is such that:
i.
By fixing an object B in
Q( op ,
y 13 : 2( � Sets is the covariant
representable functor, represented by B , and defined as follows: [ 1 ] For all objects X in 2l , y 8 (X) := HomfJJ. (B, X) . [2] For all homomorphisms f : X j Y in 2t ,
y s (f) : Hom21 (B, X) 7 Hom91. (B, Y) is defined as postcomposition with/, viz.,
y B (f)(g) := f o g .
23 1
NOTION OF LOCALIZATION PROCES SES
ii.
Correspondingly by fixing an object A i n 2i ' y A : 2t op
7
Sets is
the contravariant representable functor, represented by A , and defined as follows: A
[ 1 ] For all objects X i n 2l op , y (X) := Hom21up (X, A) .
[2] For all homomorphisms f : Y 7 X in 2l op , y
A
(f) : Hom�1op (X, A) 7 Hom2to" (Y, A) A
is defined as precomposition with/, viz., y (f)(g) := g o f . The fundamental fact is that an object A in 2t is entirely retrievable up to equivalence (canonical isomorhism) from knowledge of the A 2t p (or equivalently representable functor from y : u 7 Sets y A : 2l
�
Sets ). This fact, a consequence of a result known as the
Yoneda Lemma, 14 can be expressed this way:
Let .A , l3 be objects in a category 2( . Suppose we are given an
isomorphism of their associated functors: y
A
=
y
8
.
Then there is a
unique isomorphism of the objects themselves, that i s A = 13 , which gives rise to this isomorphism of functors. The conceptual significance of this result is that it has the following relational processtheoretic interpretation: An object A of a category 2t is determined uniquely up to equivalence by the network of all internal relations that the object A
has with all the other objects in 2t . Guerino Mazzola puts it in the fol lowing way: The revolutionary idea of ��understan ding by changing perspective" was introduced . . . In its common sense rendering, it states that i n order to understand an object, you just have to walk round the object. This seemingly trivial insight was put into a rigorous mathematical shape by Nobuo Yoneda [Yoneda 1 954]. His fam ous Yoneda lemma states that a mathematical object can be classified up to isomorphisms by its so called functor; the latter is precisely the system of all "views" or ��perspectives,' of the given object from all other obj ects of the same
232
CHAPTER 6
structure type (category). This statement even allows to construct objects via their functors. 1 5
6.4
The Methodology of Uniforiil Fibrations : Variable S et Presheaves
From the preceding it is clear that a localization scheme can be precisely conceived as a functorial generalization of the notion of functional dependence. In the trivial case, the only locus is a point serving as a unique idealized measure of localization, and moreover the only kind of reference frame is the one attached to a point. Thus, in mathematical terms, the localization process should be understood as an of some category of local or partial reference contexts on a set theoretic global structure of physical events. The latter is thus partitioned action
parameterized by the objects of the category of contexts. In this sense, the functioning of a localization scheme can be represented by means of a fib red construct, understood geometrical ly as a variable set over the base category of local reference contexts. Analogous to the case of the action of a group on a set of points, the fibers of this construct may be thought of as the 'generalized orbits' of the action of the category of local contexts. The notion of functional dependence incorporated in this action forces the partially ordered structure of physical events to fiber into sorts
.
over the base category of local reference contexts. From a physical perspective, the meaningful representation of a global ordered structure of events as a fibred construct, expressed in terms of an action of some localization scheme as depicted above, should also incorporate the requirement of uniformity. B y uniformity we mean that for any two events observed over the same domain of measurement, the structure of all reference frames that relate to the first cannot be distinguished in any possible way from the structure of frames relating to the second. According to this principle, all the localized events within any particular reference context of a localization scheme should be un iformly equivalent
to each other. The compatibility of the localization
NOTION OF LOCALIZATION PROCESSES
233
process with the requirement of uniformity demands that the relation of (partial) order in a global settheoretic universe of events is induced by appropriately
lifting a structured family of arrows from the base category
of local reference contexts to the fibers. In technical terms, the representation of a global ordered structure of events as a fibred construct via the action of some localization scheme incorporating the requirement of uniformity is modeled by the concept of a presheaj, and in particular by the category of its elements1 6 as it will be precisely fonnalized later in Part II. The meaning of uniformity with respect to the above i s depicted nicely by Nicholas Rescher in the following passage: With con creta and existence in a world, this feature of unifonnity and homogeneity
must
come
to
terms
with
differentiation
and
distinctiveness. Here every constituent substance must indeed look out upon exactly the same overall scene
exactly the same world
but it
now does so from its own distinctively characteristic point of view. Like a line or plane, there is a complete uniformity and homogeneity, but it is not the uniformity of undifferentiated sameness but rather that of synoptic hannonization. And it is the feature of unifonnity and homogeneity of coordinating overall all of those different points of view that is critical. For just this cosmic feature of reciprocal adjustment, of [Leibniz's] harrn onie universelle is one of the definitive factors for this world's perfectio n. 17
6.5
The Localization Role of Topology: Covering Sieves and Sites
Having established the concept of a local reference context, defined
according
to
the
operational
requirements
of
a
corresp onding
homologous and unifonn physical procedure of measurement, we can now
proceed
to
describe
the
mechanism
by
which
observable
infonnation, defined with respect to overlapping local reference contexts,
234
CHAPTER 6
can be glued together by appropriate means. The gluing procedure is the topological manifestation of Whitehead' s notion of extensive connection: The "extensive" scheme is nothing else than the generic morphology of the internal relations which bind the actual occasions into a nexus, and which bind the prehensions of any one actual occasion into a unity, coordinately divisible
.
.
. The primary relationship
of physical
occasions is extensive connection. 1 8
The topological character of the gluing procedure representing the process of extensive connection justifies its priority over the metrical notions of space and time. Likewise, for Whitehead: In this general description of the states of extension, nothing has been said about physical time or physical space, or of the more general notion of creative advance. These are notions which presuppose the more general relationship of extension. They express additional facts about the actual occasions. The extensiveness of space is really the spatialization of extension; and the extensiveness of time is really the temporalization of extension. 19
Mathematically, the requirement of a consistent gluing procedure is implemented by the methodology of completion of a presheaf, or 20 equivalently, its sheafification. In this way, the structure of a sheaf arises by imposing upon the corresponding presheaf the following two requirements: [i] Compatibility of observable information under restriction from the global to the local level, and [ii] Compatibility of observable information under extension from the local to the global
take together the requirements enforcing a representation of a global partially ordered structure of physical events as a uniform fibred construct over a base category of local reference contexts, localization schemes of the former are precisely modeled in the syntactical terms of sheaves. In this perspective, the evolution in the semantics of physic al level. If w e
events from a settheoretic description to a sheaftheoretic one lS completely justified, as will become clear throughout the remainder of •
NOTION OF LOCALIZATION PROCESSES
235
part II. Moreover, the technical categorical notion of a topological sheaf captures mathematically
Whitehead's conception
of an extensive
continuum as given in the passage quoted earli er: The extensive continuum is a complex of entities united by the various allied relationships of whole to part, and of overlapping so as to possess common parts, and of contact, and of other relationships derived from these primary relationships . . . It is the first detennination of order. . . The properties of this continuum are very few and d o not include the relationships of metrical geometry . . . These extensive relationships are more fundamental relationships
.
.
than .
their more special
Extension,
apart
temporal ization, is that general scheme
from
spatial its
and temporal
spatialization
of relationships
and
providing the
capacity that many objects can be welded into the real un ity of one •
expenence.
21
Up to now, we have qualified reference contexts in the base category as ' local' in a rather informal way in order to convey the intuitve nature of this qualification. In order to further j ustify the latter and clarify the precise functionality of a l ocalization scheme, it i s necessary to define a proper notion of topology on the base category of reference contexts. Then, the meaning of local, as well as the mean i ng of the transition from the local level to the global level acquires a precise connotation. 22 on The notion of a categorical or Grothendieck topology a base category of reference contexts B is a categorical generalization of a system of settheoretic covers on a topol ogy T, where a cover for U E T IS a set {Ui : uj E T, i E /} such that the union uu, u . The •
=
generalization is achieved by noting that the topology ordered by inclusion is a poset (partially ordered set) category and that any cover corresponds to a collection of inclusion arrows U,
> )
U . The notion of a
Grothendieck topology on a base category B , consisting of reference
contexts B, can thus be presented in tenns of appropriate covering devices admitting a functorial interpretation. The concept of a categorical topology requires, first of all, the abstraction of the constitutive properties of localization i n appropriate
CHAPTER 6
23 6
categorical tertns, and then, the effectuation of these properties for the definition of localization schemes. Thus, the concept of a categorical topology epitomizes the meaning of a localization scheme. Regarding these obj ectives, the requisite abstraction is being implemented by means of covering devices on the base category of reference contexts, called in categorical terminology
covering sieves. The constitutive properties of
localization being abstracted categorically in tenns of sieves, qualified as
covering sieves are the following: [i] The covering sieves should be covariant under pullback operations, viz., they should be stable under change of a base reference context; [ii] The covering sieves should be
transitive. The notion of covering sieves generalizes topologically Whitehead's
covering relations formulated in tenns of abstractive sets as discussed in chapter 5 . From a physical perspective, it is instructive to think of covering sieves as generalized topological measures of localization in the continuum. Philosophically, they express the
generic morphology of the mereotopological internal relations constituting the processtheoretic scheme of extensive connection in the continuum. The operation assigning to each reference context of the base category a collection of covering sieves satisfying the closure conditions, stated previously, gives rise to the notion of a Grothendieck topology on the base category of reference contexts. In application of these notions to quantum theory, we think of the base category of reference contexts as a category of Boolean algebraic contexts related to typical quantum measurement situations?3 It is a physical fact that any quantum measurement s ituation involves the preparation of a Boolean algebraic reference context (conceived locally in a proper way) with respect to which a measurement value can be obtained operationally by the use of some measurement device. In this setting a fundamental admonition is given in the KochenSpecker theorem,24 according to which the complete description of a quantum mechanical system is impossible to produce by way of a single system of Boolean devices extended globally. By contrast, in every concrete quantum m easurement context, the set of logical events that can be
NOTION OF LOCALIZATION PROCESSES
237
that context fonns a Boolean algebra. This fact motivates the assertion that a Boolean algebra within the partially ordered set of quantum logical events plays the role of a local logical reference frame relative to which a measurement result is coordinatized. Thus, in the actualized in
words of Arthur Eddington: In Einstein ' s theory of relativity the observer is a man who sets out in quest of
truth
armed with a measuringrod [a metrical concept]. In 5 ? quantum theory he sets out with a sieve [a topo l o gi cal concept]
The construction of a suitable Grothendieck topology on the base category o f contexts is significant for the following reasons: First, it explicitly elucidates, with great precision, the conceptions of local and global in a categorical measurement environment, such that these
detachedfrom their restricted spatial connotation in terms of geometric pointspaces the latter being wholly absent in the conceptions become case
of quantum theory. Instead, these conceptions are
depicted
relational observable information. Secondly, it permits the gluing of local observable information terms into global ones exclusively in terms of
by utilization of the notion of a sheaf for a suitable Grothendieck topology. Thi s is most easily demonstrated by first exploring the general notion of sieves, introduced earlier, and then proceeding to focus on the notion of covering sieves. I n preface, it is instructive to note at this stage that in the usual definition of a localization scheme induced by a topological space
X
we use the
open neighborhoods
neighbo rhoods are actually inclusions U >
�
U of a point in
X;
such
X The neighborhoods U .
in topological spaces can be replaced by morphisms of reference contexts
C ? B , not necessarily inclusions, and this can be done in any comp lete
category. In effect, a covering of a topological space by open sets can be replaced by a new notion of covering, provided by a fami ly of morphisms targeting some object in a categorical environm ent, and sati sfying the above conditions [i] and [ii], which abstract the decisive features of a localization process.
238
CHAPTER 6 A Bsieve with respect to a reference context B in the base category
!3 is a family S of B morphisms targeting B, such that if C ) B
belongs to S and D � C is any B morphism, then the composite D
�
C
�B
belongs to S. We may think algebraically of a Bsieve as a
right Bideal. We notice that in the case of O(X) , since O(X) morphisms are inclusions of open loci, a right Uideal is identical with a
downwards closed Usubset. We notice that if S is a Bsieve and h : C � B is any arrow to the ref�rence context B, then: h (S) = {f / cod(f) = C, (h o j) E S} is a C ..
sieve, referred to as the pullback of S along h , or the restriction of S
along h where cod(f) denotes the codomain off. We notice that for a '
context B in B , the set of all arrows into B is a Bsieve, called the
maximal sieve on B, and denoted by, t(B) := tB .
As we proceed to the next stage of development, the key conceptual issue to b e settled is the following: How is it possible to restrict or
reduce the set of all Bsieves for each reference context B in B , denoted by K(B) , such that each Bsieve of the restricted set can acquire the interpretation of a covering Bsieve with respect to a generalized covering system? Equivalently stated, we wish to impose the satisfaction of appropriate conditions on the set of Bsieves for each context B in B such that the subset of Bsieves obtained, denoted by
,
Kx (B) ,
implements the constitutive properties of a localization process. In this sense, the Bsieves of Kx (B) for each locus B in !3 , to be thought as covering Bsieves, can be legitimately used for the implementation of localization processes. The appropriate conditions depicting the covering B sieves from the set of all Bsieves, for each reference context B in 13 , are the following: [1] We interpret an arrow C __, B , where C,B are contexts in !3 , as a figure of B, and thus we interpret B as an extension of C in B . It is a natural requirement that the set of all figures of B should belong
1n •
K x (B) for each context B in B . [2] The covering sieves should be stable under pullback operations. This requirement means, in particular, that the intersection of covering
NOTION OF LOCALIZATION PROCESSES .
239
sieves should also be a covering sieve, for each reference context B, in the base category B .
(3] Finally, it would be desirable to impose: [i] a .transitivity
requirement on the specification of the covering sieves, such that, intuitively stated, covering sieves of figures of a context in covering sieves of this context, should also be c·overing sieves of the context themselves, and [ii] a requirement of common refinement of covering s1eves. •
If we take into account the above requirements we can define a generalized covering system, called a Grothendieck topology, in the environment of the base category B as follows: A Grothendieck topology on B is an operation J , which assigns to each reference context B in B , a collection J(B) of Bsieves, called covering Bsieves, such that the following three conditions are satisfied: [ 1 ] For every reference context B in
{g : cod(g)
==
B,
the maximal Bsieve
B} belongs to J(B) (maximality condition).
[2] If S belongs to J(B) and h : C � B is a figure of B, then h * (S) = {/ : C � B, (h o f) E S} belongs to J(C) (stability condition).
[3] If S belongs to J(B) , and if for each figure h : Ch * B in S, there is a sieve Rh belonging to J(Ch) , then the set of all composites
h o g , with h E S , and g E Rh , belongs to J(B) (transitivity condition).
As a consequence of the definition and conditions above, we can easily verify that any two Bcovering sieves have a common refinement, that is: if S,R belong to J (B) , then S n R belongs to J (B) . As a first application we may consider the partially ordered set of open subsets of a topological space X, viewed as the base category of open reference contexts, O(X) . Then we specify that S is a covering U Sieve if and only if U is contained in the union of open sets in S. The above specification fulfills the requirements of covering sieves posed above, and consequently, defines a Grothendieck topology on O(X) . •
A category of reference contexts 13 together with a Grothendieck topology J , is called a site, denoted by (13, J) . The notion of a site generalizes the notion of a topological measurement state space in cate gorical tenns and constitutes the relational variable topological
240
CHAPTER 6
background for the effectuation of a localization scheme for filtering or coarsegraining or grading the information contained in a global structure of partially ordered physical events. This filtering occurs via localizing structural frames determined by a homologous operational physical procedure of measurement. As will be demonstrated throughout the remainder of Part II, this conceptual framework is uniquely suited to the coherent and consistent description of localization processes in quantum theory. The basic idea is to associate the functioning of a localization scheme in a global quantum event continuum with covering sieves of local Boolean contexts of quantum measurement. Before applying the machinery of sites to quantum theory, however, it is instructive to discuss in detail the important, simplest case of a localization scheme induced by a topology on a space.
Notes 1.
Roland Omnes, The Interpretation of Quantum Mechanics (Princeton: . Princeton University Press, 1 994). 2. H. Poincare, The Foundations ofScience: Science and Hypothesis, The. Value of Science and Methods (New York: The Science Press, 1 92 1 ), 52. 3 . Alfred North Whitehead, Process and Reality: An Essay in Cosmology, Corrected Edition, ed. D. Griffin and D. Sherburne (New York: Free Press, 1 978), 63 . 4. Whitehead, Process and Reality, 288. 5. Whitehead, Process and Reality, 66. 6 . Whitehead, Process and Reality, 67. 7. Whitehead, Process and Reality, 288. 8. S. Awodey, Category Theory, Oxford Logic Guides (Oxford: Oxford University Press, 2006). 9. Elias Zafiris, "Probing Quantum Structure Through Boolean Localiza tion Systems,'' International Journal of Theoretical Physics 39, no. 1 2 (2000); Elias Zafrris, "Boolean Coverings of Quantum Observable Structure: A Setting for an Abstract Differential Geometric Mechanism," Journal of Geometry and
NOTION OF LOCALIZATION PROCESSES
Physics
24 1
50, no. 99 (2004); Elias Zafrris, "Interpreting Observables in a Quantum
World from the Categorial Standpoint," International Journal of Theoretical Physics
43, no. 1 (2004).
1 0 . J. L. Bell, "From Absolute to Local Mathematics," Synthese 69 (1 986);
J. L. Bell, "Categories, Toposes and Sets," Synthese
5 1 , no. 3 ( 1 982).
1 1 . We note that an interesting analysis of the general notion of duality
from a processtheoretic standpoint has been presented in T. E. Eastman, "Duali ty without Dualism" in Physics and Wh itehead, ed. T. Eastman and H. Keeton (Albany: State University of New York Press, 2004).
1 2. Whitehead, Process and Reality, 29 1 . 1 3 . Whitehead, Process and Reality, 292. 14. Awodey, Category Theory; S. Mac Lane and I. Moerdijk, Sheaves in Geometry and Logic (New York: SpringerVerlag,
1 992).
1 5. Guerino Mazzola, "Towards Big Science: Geometric Logic of Music and Its Technology" (paper presented at KlangArtKongress 1 995, Universitat Osnabrock).
1 6 . Mac Lane and Moerdijk, Sheaves in Geometry and Logic. 17. N. Rescher, Studies in Leibniz 's Cosmology (Berlin: OntosVerlag,
2006), 86. 1 8. Whitehead, Process and Reality, 288. 1 9 . Whitehead, Process and Reality, 289. 20. Mac Lane and Moerdijk, Sheaves in Geometry and Logic. 2 1 . Whitehead, Process and Reality, 66. 22. Mac Lane and Moerdijk, Sheaves in Geometry and Logic. 23. Elias Zafiris, "Probing Quantum Structure Through Boolean Localiza tion Systems," International Journal of Theoretical Physics 39, no. 1 2 (2000); Elias Zafiris, "Boolean Coverings of Quantum Observable Structure:
A Setting
for an Abstract Differential Geometric Mechanism," Journal of Geometry and Physics
50, no. 99 (2004); Elias Zafiris, "Interpreting Observables in a Quantum
World from the Categorial Standpoint," International Journal of Theoretical Physics
43, no. 1 (2004).
24. Simon Kochen and Ernst Specker, "The problem of hidden variables in quantum mechanics," Journal of Mathematics and Mechanics 1 7 (1 967): 5987.
25. A. S. Eddington, The Theory of Groups in The World of Mathematics, Vol. 3, ed. J. R. Newman (New York: Dover, 2003).
CHAPTER 7
Sheaves of Germs: The Topological Case
7.1
Localization over a Topological Space
The topological case refers to a localization scheme on a global partial order of physical events. These events are defined as taking place over a base category of reference contexts 0(X) , consisting of open sets U of a topological measurement space X, the arrows between them being inclusions. In this case, the reference contexts of the operational environment employed for observation are all the open sets U of X, partially ordered by inclusion. Equivalently, the open set inclusions U > � X are considered as varying base reference frames of open loci over which a global partial order of events fibers. We may use the suggestive term ' local observer' to refer to an eventregistering device associated with a reference context U of the base category O(X) . Note that the meaning of ' local' here is understood with respect to the topology of X, such that a 'local observer' in a measurement situation taking place over a reference context U individuates events by means of local realvalued observables, being continuous maps s : U � JR . Thus, the 'local observers' do not have a global 'perception' of continuous functions f : X � IR , but rather always register events as localized over the associated reference contexts in tenns of local observables. Of
CHAPTER 7
244
course, appropriate conditions are further needed for gluing their findings together; as will be explained presently, these conditions are the necessary and sufficient conditions for a topological sheaftheoretic structure.
7.2
Uniform Localization of Observables
In order to clarify the functioning of a topological localization
process, we will describe in detail the important case of localization of a commutative, unital lR algebra of observables of some system over a base localizing category O(X) . S ince observables are thought of as
global functions on the lR coordinatized statespace of this system, the process of localization forces the replacement of the algebra of global observables A by an algebraic structure which will give us all local and
global junctional information together. All these functional elements should interlock compatibly together in an appropriate manner, which is characterized by the property that the combined structure respects the
extension from local to global, as well as the restriction from global to local implied by the localization process. This structure is precisely fonnalized by the notion of a sheaf ofgerms of a commutative, unital � algebra of observables, denoted by A , which incorporates all compatib le local and global infor1nation together. Let us first introduce precisely the general notion of a sheaf on a topological space, and then examine its applicability in the current situation. For this purpose, we consider the category of open sets O(X) in a topological space, partially ordered by inclusion. If V(X)op is th e .
opposite category of O(X) , and Sets denotes the category of sets, we define: A presheaf of sets on O(X) is a contravariant setvalued functor on V(X) , denoted by P : O(X) op � Sets . For each base open set U of V(X) , P ( U) is a set, and for each arrow F : V � U , P (F) : P(U) ? P (V) is a setfunction. If P is a presheaf on O(X) and
p E P (U) , the value P (F)(p) for an arrow F : V � U in V(X) is
SHEi\VES OF GERMS: THE TOPOLOGICAL CASE
called the
A
245
restriction of p along F and is denoted b y P( F)(p) := p . F
presheaf
P may be understood as a right action of 0 (X) on a set.
This set is partitioned into sorts parameterized b y the obj ects of
0 (X) ,
F : V 7 U i s an inclusion arrow in p i s an element of P of sort U , then p F i s specified as an P of sort V . Such an action P is referred to as an 0 (X)
and has the following property: If
0 (X)
.
and
·
element of
variable set. A variable set of this form is entirely determined by its category of elements.
category of elements of a presheaf P , denoted b y J(P,O (X)) , is
The
described as fol l ows: The objects of
U
J(P,O (X))
are all pairs
(U, p) ,
O (X ) and p E P(U) . The arrows of j(P,O (X)) , that is, (U', p') 7 (U, p) , are those morphisms Z : U � 7 U i n O (X ) , such that p' = P(Z)(p) := p · Z . Notice that the arrows in f(P, O (X)) are those morphisms Z : U' � U in the base category 0 (X) that pull a chosen element p E P(U) back into p' E P(U') . The category of elements J(P,O (X)) of a presheaf P , together with the projection functor f P : J(P,O (X)) 70 (X) , i s called the split discrete fibration induced by P 1, where 0 (X) is the base category of the with
in
fibration. We note that the fibers are categories in which the only arrows are identity arrows. inverse image of
If U
U
is an open reference context of
under
JP
0 (X)
,
the
is simply the set P (U) , although its
elements are written as pairs so as to form a
disjoint union.
From a physical viewpoint, the purpose of introducing the notion of
0 (X) i s the following: We identify an element of P is p E P(U) , with a local observable, which can
a presheaf P on sort
U,
that
of be
observed by means of a measurement procedure over the reference context
U,
being an open set of a topological space
X. Th is
identification
forces the interrelations of local observables, over all reference contexts of the base category
0 (X) ,
to fulfill the requirements of a uniform and
hom ologo us fibred categorical structure. The l atter are to be understood acc ording to the following two requirements: First, the reference contexts used
for
morphisms,
observational
purposes,
together
should form a mathematical
with
category.
their
structural
The notion of
uniformity implies that for any two local observables, being amenable to
CHAPTER 7
246
a measurement procedure over the same open domain of measurement U, the structure of all reference contexts that relate to the first cannot be distinguished, in any possible way, from the structure of contexts relating to the second. According to this, all the localized observab les within any particular reference context should be uniformly equivalent to each other. The split discrete fibration induced by P , where 0 ( X ) is the base category of the fibration, provides a welldefined notion of a uniform homologous fibred structure of local observables in the following two ways; [ 1 ] By the arrows specification defined in the category of elements of P , any local observable p , determined over the reference context U , is homologically related with any other local observable p/ over the reference context U ' , and so on, by variation over all the reference contexts of the base category; [2] All the local observables p of P of ,
the same sort U , viz., determined over the same reference context U , are uniformly equivalent to each other; this is because all the arrows in f(P,O (X)) an� induced by lifting arrows from the base category O (X ) , being formed by partially ordering the reference contexts. We conclude that the topological localization process is consistent with the physical requirement of uniformity.
7.3
Gluing S ections and LocaltoGlobal Compatibility
The next crucial step of the construction aims at the satisfaction of a second physical requirement: Since we have assumed the existence of reference contexts (open observational domains) locally, according to the operational requirements of a corresponding physical procedure of measurement, the information gathered about local observables in different measurement situations should be collated together by · appropriate means. Mathematically, this requirement is implemented via the completion of the presheaf P , or equivalently, sheafification of P .2
247
SHEAVES OF GERMS: THE TOPOLOGICAL CASE
A sheaf is characterized as a presheaf P that satisfies the fol lowing condi tion: If U = U a Ua ,
a
Ua
in V(X) , and elements Pa E
E I : index set, are such that for arbitrary
where
uab
:=
ua
n
ub
'
and the sym bo I I
a, b
P (Ua ) ,
E I , it holds:
denotes the operation of
restriction on the corresponding open reference context, then there exists a unique element p E P(U) , such that p I Ua = Pa for each a in I . Then an element of P(U) is called a section of the sheaf P over the open context U . The sheaf condition means that sections can be glued together uniquely over the reference contexts of the base category 0( X) . In particular, the sheaftheoretic qualification of a unifonn and homologous fibred structure of observables, as above, also makes the latter
coherent
in tenns of localglobal
compatibility
of the information
content it carries, under the inverse operations of restriction and extension. Thus, we form the following conclusion: The structure of a sheaf arises by imposing the following two requirements upon the unifonn and homologous fibred structure of elements of the corresponding presheaf:
Compatibility of observable information under restriction from the global to the local level, and [ii] Compatibility of observable information under extension from the local to the global level. According to the first of the above requirements, a sheaf constitutes a separated presheaf of [i]
local observables over a global topological space, meaning that two observables are conceived as being identical globally if and only if they are identical locally. In turn, according to the second requirement, locally compatible observables can be glued together within some global observable,
which
is also uniquely defined because
of the first
requ irement. Furthermore, it is obvious that each set of sort U , P(U) , can be endo wed with the structure of an
1R

algebra
under pointwise sum,
p ro duct, and scalar m ultiplication, denoted correspondingly by
A(U) ; in
CHAPTER 7
248
that case, the morphisms
A(U) + A(V) stand for
�
..
Jinear morphisms
of JR algebras.
7.4
C ontextuality: Germs and Stalks of Observable S heaves
Now we shall introduce the physically important notions of stalks and germs of a sheaf. For this purpose it is necessary to explain the construction of the inductive limit (categorical co limit) of sets (or lR algebras) of observables
A(U) , denoted by Colim[ A(U)]
.
Let us
consider that x is a point of the topological measurement space X Moreover, let K be a set consisting of open subsets of X, containing x, such that the following condition holds: For any two open reference contexts U , V , containing x, there exists an open reference context contained in the intersection u n v . we may say that K wEK '
constitutes a basis for the system of open reference contexts around x. We form the disjoint union of all
A(U) , denoted by:
D(x) := Il ueK A(U) Then, we can define an equivalence relation in D(x) by requiring that p r'..1 q for p E A(U) q E A(V) provided that they have the same ,
,
restriction to a smaller open set contained in K . Then we define:
ColimK[A(U)] := D(x)/
rv
K
Notice that if we denote the inclusion mapping of V into U by:
iv u : V > � U ,
and also the restriction morphism of sets from
U to V by:
SHEAVES OF GERMS: THE TOPOLOGICAL CASE
249
Pu,v : A(U) )> A(V) we can introduce welldefined notions of addition and multiplication on the set
Colimx [A(U)] making it an R algebra.
Now, if we consider that
K and
open reference contexts around canonical isomorphisms between
x
A are 1:\vo bases for the system of
E X , we can show that there are
Colimx[A(U)]
ColimA[A(U)] .
and
particular, we may take all the open subsets of X containing
x :
In
Indeed,
K is arbitrary and A i s the set of all Then A ::) K induces a morphism:
we consider first the case when open subsets containing
x
.
Colimx [A(U)] )> ColimA [A(U)] which is an isomorphism, because whenever V containing
x
,
there exists an open subset
U
in
is an open subset
K contained in V . Since
we can repeat that procedure for all bases of the system of open sets domains around
x
E X , the initial claim fol lows immediately.
stalk of A at the point x E X , denoted by A x , is defined inductive limit of sets (or IR algebras) of observables A(U) :
Then, the as the
ColimK [A(U)] := lluex A(U)I where and
K
� K
rv
K
is a basis for the system of open reference contexts around
x,
denotes the equivalence relation of restriction within an open set
in K. Note that this definition is
an open reference context morphism of
A(W)
W
independent
of the chosen basis
containing the point
into the stalk at the point
x :
iw,x : A(W) � A x For an element
p E A(W)
its image:
iw,x (p) :== Pr
=
germxp
x,
K. For
we obtain an
250
CHAPTER 7
is called the germ of p at the point x. The fibred structure that corresponds to a sheaf of sets (or JR algebras) of observables A is a
topological bundle defined by the continuous mapping rp : A > X ,
where:
A = IIxex Ax
rp1 (x) = A x = Colim{xeu} [A(U)] 3 The mapping rp is locally a homeomorphism of topological spaces.
The topology in A is defined as follows: for each p E A(U) , the set ·
{px, x E U} is open, and moreover, an arbitrary open set is a union of
sets of this form . In the physical state of affairs, we have identified
an
element of A of sort U that is a local section of A , with a local observable
p
,
which can be observed via a measurement procedure over
the reference context U. Then the equivalence relation used in the defmition of the stalk A x at the point x E X is interpreted as follows: Two local observables p E A(U) and q E A(V) induce the same
contextual information at x in X provided that they have the same restriction to a smaller open context contained in the basis K. Then the stalk A x is the set containing all contextual information at x , that is, the set of all equivalence classes. Moreover, the image of a local observable p E A(U) at the stalk A x , that is, the equivalence class of this local observable p , is precisely the gertn of p at the point x. Next, if we consider a local observable p E A(U) , it determines a function: p : x r7 germxp •
whose domain is the open locus U and its codomain is the stalk A x for each x E U . Obviously, we may consider instead the disjoint union A = Ilxex Ax as the codomain of the function p . In this sense, evert local observable p E A(U) gives rise to some partialfunction:
SHEAVES OF GERMS: THE TOPOLOGICAL CASE
251
U c X . Hence, all local admit a functional representation, established by
which is defined on the open reference context observables
p E A(U)
means of the following correspondence: 11(U) : p
H p
Stated equivalently, each local observable p
E
A(U) can be legitimately
considered as a partial function:
p : U )> A defined over the open reference locus U, the value of which, at a point
x
contextual observable information induced at x by the local observable p Further1nore, such a partial function P : U ) A is identified with a cross section of the topological bundle of germs, defined by the continuous mapping rp : A � X such that: E
U , viz., germxp ,
is the
.
,
q71 (x) == A x = Notice that the mapping
Colim{xeu}[A(U)]
qJ is locally a homeomorphism of topological
display bundle (called equivalently an etale bundle). Now, as a consequence of the equivalence between sheaves on a topological space X and display topological bundles over X, every sheaf can be considered as a sheaf of cross sections ofthe equivalent display topological bundle .4 spaces, and thus the bundle is a topological
252
7.5
CHAPTER 7
Completion and Functionalization : Display Bundles
It is also instructive to notice that the previous arguments can help us to understand the process of completion (or sheafification, or 5 germification) of a presheaf. For this purpose, we realize that the notions of germ, stalk and display bundle make sense for a general presheaf. More precisely, the germ at a point stands for an equivalence class of elements of the presheaf corresponding to open reference contexts around that point, under the equivalence relation of having the same germ. The stalk over this point is the set of all germs at this point. The display bundle is the disjoint union of all stalks. The first crucial observation is that by the definition of a topology on the display bundle, as described previously, it is legitimate to consider continuous sections of the display bundle. Stated equivalently, this procedure amounts to transforming the elements of the presheaf into partial continuous functions (continuous sections) valued into the display space. Hence, we manage to functionalize the initial presheaf, by defining a new presheaf, called the presheaf of sections of the initial presheaf as follows: It is the presheaf, which associates to each open locus of the base topological space the set of continuous sections from that open locus into the display space. Now, there is an obvious morphism from the initial presheaf to its presheaf of sections a morphism that maps each element of the category of elements of the initial presheaf to the continuous section, thus sending each point in an open reference context of the base space to the gerrn of this element at that point. The second crucial observation is that the associated functionalized presheaf of sections of a presheaf is actually also localized ( l oc ally determined), viz., it is a sheaf, identified as the sheaf of cross sections of the corresponding topological display bundle. Thus, the latter sheaf is called the sheaf associated with the initial presheaf Moreover, the process of completion of a presheaf into the sheaf of cross sections of the
SHEAVES OF GERMS: THE TOPOLOGICAL CASE corresponding topological display bundle is
functorial,
253
meaning that
there exists a functor sending each presheaf to its completion, viz., to its
sheafification functor. As a corollary, we conclude that a presheaf is a sheaf, viz., a complete presheaf, if and only ifthe morphism to its associatedfunctional presheaf of sections is an isomorphism. Thus, the process of completion of a presheaf is equivalent to the combined processes ofjunctionalization and localization of its elements. Consequently, the associated sheaf of associated sheaf of sections, called the
sections of a corresponding presheaf contains, by its construction, the totality of local
contextual information compatible with that given in the
initial presheaf via its restriction property. In this sense, the sheaf constitutes the completion of the presheaf.
7o6
Events: From SetTheoretic to SheafTheoretic Semantics Now, let us consider a sheaf of
R algebras of local observables,
identified as a sheaf of realvalued continuous crosssections of the corresponding display bundle. Then, the set of germs of all these sections at a point, viz., the stalk at this point, i s also an •
Important, the stalk at this point is a local a
unique maximal ideal.
lR algebra. Most
R algebra, meaning that it has
In turn, this maximal ideal consists of all germs
vanishing at the considered point. The quotient of the stalk by this maximal ideal is isomorphic to the field of real numbers. Equivalently, this means that the morphism evaluating a germ of the stalk at a point to the real numbers (viz., providing a real value at the corresponding non vanishing equivalence class
of sections
at the considered base point) is a
surjective morphism of � algebras having for a kernel the maximal ideal of the stalk at this point:
254
CHAPTER 7
germxp M evx(germxp) = p(x) Thus, the evaluation morphism of a germ of the stalk at a point of the base space is an R valued measurement of this observable gem1, interpreted
as
an observed event of the corresponding system, and
subsequently encoded by means of an JR state of its topological state space. Proceeding to the next stage of the development of this framework, th� sheaf of gern1s of realvalued continuous functions on a topological space X is an object in the functor category of sheaves Sh(X) on varying reference contexts U, being open sets of X, partially ordered by inclusion. The morphisms in Sh(X) are all natural transfortnations 6 between sheaves. It is instructive to notice that a sheaf makes sense only if the base category of reference contexts is specified, which is equivalent to the deter1nination of a topology on the space X. The functor category of sheaves Sh(X) provides an exemplary case of a construct known as topos. 7 A topos can be conceived as a local
mathematical framework corresponding to a generalized model of set theory, or as a generalized algebraic space, corresponding to a categorical universe of variable observable infonnation sets over the multiplicity of the reference contexts of the base category. We recall that fotmally a topos is a category, which has a tenninal object, pullbacks, exponentials, and a subobject classifier, which is understood as an object of generalized truth values. The particular significance of the sheaf of realvalued continuous functions on X is due to the following isomorphism: The sheaf ofgerms of continuous realvaluedfunctions on
X is isomorphic to the object of Dedekind real numbers in the topos of sheaves Sb(X) .8 This isomorphism validates the physical intuition of considering a local observable as a continuously variable real number over its context of definition. The transition in the semantics of the 'physical event continuum' from the topos of Sets to the topos of sheaves Sh(X) is an instance of the basic idea of sheaftheoretic localization of physical observability referring to the interpretation of observed events. We initially notice that
SHEAVES OF GERMS : THE TOPOLOGICAL CASE
255
in the former case observables are identified with (continuous) functions determined completely by their values at points. In the latter case observables are identified with local continuous sections of the display space determined completely by their germs. In order to analyze in more detail the transition in the semantics, vve from a base
note that in the former case a continuous function topological space
X to
the topological space R can b e considered as a
continuous section from
X
to the product space
XxR
. This product
space i s isomorphic settheoretically to a space having a copy of each point, being the inverse image of the proj ection from base
X.
X xR
R at to the
The value that is taken at a point is the value taken by the
function. Thus, this type of modeling
is
only
l atter case we strive to capture
local
of an
observable
appropriate in capturing its point properties.
In contradistinction, in the properties of observables. This environ ment, we associate
is because in the sheaftheoretic local
not the value that a section takes at a point of·
the base space but its germ. In this sense, instead of the product total space
X xR
, we have the topological display space, such that the
•
Inverse image of each point of the base space is not a copy of
R , but the
stalk at that point. This essentially means that the transition of semantics from the topos of sets
Sets
to the topes of sheaves
Sh(X)
amounts to a
shift of focus from pointwise descriptions of observables to local descriptions of observables. Obviously the topological display space i s a much richer and larger sp ace than the rigid space informatio n about the
X xR
,
since the display space provides
local behavior of observables around each point of
the base space in terms of germs, instead of merely pointwise behavior of observables in terms of their values in the real numbers. Thus,
observed events are not determined by the values of continuous functions (observables) at points of the base space, but by the evaluation rnorphisms of observable genns at those points, according to our previ ous remarks.
We conclude that the meaning of the idea of sheaftheoretic
loc alization
of physical observability referring to the interpretation of
CHAPTER 7
256
observed events, effectuated by the transition from the topes of sets to the topos of sheaves Sh(X) , amounts to a with respect to the
local behavior of
Sets topological relativization
physical observables as opposed to
their point behavior. Let us now further elaborate the sheaftheoretic semantics of observed events from a processtheoretic standpoint. We argue that each event is a
novel actualizedfact and
respects the selection constraints of
the local context with respect to which it can be individuated. Thus events are essentially individuated and actualized with respect to local reference contexts U in V(X) . It is crucial to notice that an event is not specified sheaftheoretically by the evaluation of an observable, but rather by the evaluation of a corresponding observable germ; that is, event is specified in a global sense by the
compatible
an
equivalence class of all
local reference contexts conceived in all different local levels
nested within each other with respect to which observable information can be glued.. Thus an observable germ is precisely the semantic information carrier of a
seed of extension
in the ontological fonnation of the
continuum; it is, in other words, the germ of extensive connection from the local to the global via the topological gluing procedure. Notice also that the notion of a germ is
not
defined in abstraction from its local
context, since its very defmition makes sense only with respect to such a local context, where local sections agree. Moreover
in the conception of
considered apart from the lo cal information content which is contextualized. It is thus useful to think of a germ, a local context is
internal constitution of actual occasions tn concrescence, since they i ntegrate compatible
germs as representing the their
process
of
never
•
information at higher and higher local levels (reference contexts) by the
formation of equivalence classes. In this way, it is via the concept of the be can germ that an actual occasion's objective global relevance
. bal lo analyzed that is, via the semantic transition from the local to the g e h t ed In Whiteheadian philosophy, an actual occasion is consider
starting point of its own process of concrescence, and this pro cess 15 analyzable ' genetically.' In terms of the sheaf theoretic fram ework •
SHEAVES OF GERMS:
1HE
TOPOLOGICAL CASE
257
presented herein, the genetic division constitutive of an actual occasion is perfectly represented via the concept of the ger1n. Thus an actual occasion determines its germ of local observables or local sections. This, in turn, involves the determination of an appropriate local context with respect to which the genn is initially defined and eventually evaluated or actualized. The actualization or 'satisfaction' of the actual occasion's process of concrescence, in other words, can be understood in the context of quantum m easurement as the evaluation
I actualization of this genn
as
a quantum event.
7.7
Covering Sieves as Representable Functors
Before explaining the applicability of sheaftheoretic localization of physical observability to the concept of a ' quantum event continuum,' it is important to first revisit and clarify the notions of sieves and covering sieves introduced in Chatper
6 as they p ertain to the topological
localization process discussed above. A reference context
U
U sieve
with respect to a
in V(X) , is defined as a family
S of V(X)
V + U belongs to S and D � V is any O(X) morphism, then the nested composite inclusions (inte rnal relations among local reference contexts) D + V 4 U belongs to S . Now, since all O(X) morphisms are inclusions, a U sieve with resp ect to U is actually a downwards closed U subset. morphisms with codomain
U,
such that if
If we consider the contravariant representable functor of U in
O(X) , vi z. , the network of all internal relations that the reference
U has with all the other contexts in V(X) , denoted by Y[U] := Homocx) ( , U) , then it is easy to realize that a U sieve is equivalent to a subfunctor S > ' y[ U] in Setsv cx)op . context
In detail, given a
U sieve S , we define:
S(V ) == {g I g : V � U, g E S} � y [ U](V)
CHAPTER 7
258
This definition yields a functor S in Sets V(x)op , which is obviously a subfunctor of y[U] . Conversely, given a subfunctor S > > y[U] in
vc Sets x)op , the set:
S = {g l g : V ) U, g e S (V)} for some reference context V in C?(X) , is a U sieve. Thus, we conclude:
( U sieve: S ) = ( Subfunctor of y[U] : S > ; y[U] ) We notice that if S is a U sieve and h : V � U is any inclusion to the reference context U , then:
h * (S) = {/ I cod(f) = V, (h o f) E S} is a V sieve, called the pullback of S along h . Consequently, we may define a presheaf functor K in Sets ocx)op , such that its action on reference contexts U in V(X) , is given by:
K(U) = {S I S : U  sieve} and on arrows h : V � U , by h'" ( ) : K(U) 4 K(V) , given by:
h* (S) = {f I cod(f) = V, (h o f) E S} We notice that for a reference context . U in V(X) , the set of all inclusion arrows into U, called the maximal sieve on U, and denoted by t(U) := tu , is a U sieve. Moreover, if we consider the partially ordered set of open subsets of a topological space X, viewed as the base category of open reference contexts, V(X) as above, then a U sieve S (where U is an open reference context) is a covering U sieve if and only if U is
contained in the union of open sets in S. This fulfills the requirements of covering sieves, and consequently, defines a Grothendieck topology J on
SHEAVES OF GERM:S: THE TOPOLOGICAL CASE
259
V(X) . A Grothendieck topology J exists as a presheaf functor
Sets0(X )op ,
such that . by
gives· the
set
whereas
by
of
acting
all on
Kx in acting on reference contexts U in V(X) , J covering U s i ev es, denoted by K z (U) ; figures h : V 4 U it gives a morphism 
,
h. () : ·K x (U) � Kx (V) , expressed as: h
•
(S)
=
{f I cod (f)
=
V, (h f) E S} , for S E K x (U) . o
Notes 1. S. Mac Lane and I. Moerdijk, Sheaves in Geometry and Logic (New York: SpringerVerlag, 1 992). 2. Mac Lane and Moerdijk, Sheaves in Geometry and Logic. See also: A. Mallios, Geometry of Vector Sheaves: An Axiomatic Approach to Differential Geometry, Vol. 1 (Kluwer Academic Publishers, Dordrecht, 1 99 8). 3. To each a in A there exists an open set V, with a e V � A , such that rp(V) is open in X and fP 1 V is a homeomorphism (continuous function that has a continuous inverse) V � cp(V) . 4. Mac Lane and Moerdijk, Sheaves in Geometry and Logic. See also: Mallios, Geometry of Vector Sheaves, and A. Mallios, "On Localizing Topological Algebras," Contemporary Mathematics 341, no. 79 (2004). 5. Mallios, "On Localizing Topological Algebras." 6. Mac Lane and Moerdijk, Sheaves in Geometry and Logic. 7. S. Awodey, Category Theory, Oxford Logic Guides (Oxford: Oxford University Press, 2006). See also: Mac Lane and Moerdijk, Sheaves in Geometry and Logic.
8.
Mac Lane and Moerdijk, Sheaves
in Geometry and Logic.
Sheaves of Boolean Germ s : The
8.1
u antum Topological C ase
Quantum Logical Event Algebras and Observables
The quantum case refers to a localization scheme on a global partial order of quantum physical events L taking place over a base category of reference contexts
B
.
This base category consists of Boolean
algebras B
associated with the operational procedure of quantum measurements, the arrows behveen them being Boolean algebra homomorphisms. In this case, the reference contexts of the operational environment employed for observation are all the Boolean algebras not inclusions but
all Boolean
B, whereas their morphisms are
homomorphisms. Equivalently, the arrows
B � L are considered as varying base reference frames of Boolean algeb ras over which a global partial order of quantum events L fibers. Consider now the algebra L of
logical events
associated with the measurement of a quantum
logical event algebra
propositions system . A quantum or
L .in .C is a partially ordered set of quantum
logical events, endowed with a maximal element 1 , and with an operation of orthocomplementation []• : L � L , which satisfy, for all
l E L , the following conditions:
262
CHAPTER S
[a] l � 1 [bJ z··
=
z
[c] l v t· = 1
[e] l .l l' => l v l' E L [±] for l, l' E L, l � l' implies that l and !' are compatible, where 0 := 1 , l j_ l' := l ::;.; l' · , and the operations of meet 1\ and join v ..
are defined as usuaL Recall that l,l' E L are compatible if the sublattice generated by
{!, /* , l ', l' * }
is a Boolean algebra,
namely, if it is a Boolean sublattice. In order to have a well defined theory of observables over L , we also impose a a
completeness condition, namely that the join of countable families of pairwise orthogonal events exists. It is important to notice here that a quantum logical event algebra L is not a Boolean algebra. It is technically called an orthomodular cr orthoposet. We can now construct a locally small cocomplete category, denoted by £ , which is called the category of quantum logical event algebras. The objects of £ are the quantum logical event algebras L , whereas the arrows of £ are quantum algebraic homomorphisms, defined as follows: A quantum logical algebraic homomorphism in .C is a morphism
H : K � L , which satisfies, for all k E K , the following conditions: [a] H( l ) = 1 [b] H(k · ) = [H(k)]* [c) k � k' :::> H(k) � H(k')
THE QUANTUM TOPOLOGICAL CASE [d )
263
k j_ k' => H(k v k') � H(k) v H(k')
quantum observable S from the Borel algebra of the algebra L , A
is defined to be an algebraic morphism real line
Bar(�)
to the quantum
event
B : Bor(JR) � L such that: [a]
3(0) = 0 , S(R) = l
[b]
EflF = 0 � S(E) j_ B(F) , for E, F E Bor(JR)
[c]
3(Un En ) = v n3(En ) , where E1 , Ez , . . . is a sequence of mutually disjoint Borel sets of the real line.
Addition and m ultiplication over observables the structure of a
ffi. induce on the set of quantum
partial commutative algebra
over � . In
most of the cases the stronger assumption of a noncommutative algebra of quantum observables is adopted. Thus, we may construct a category, denoted by VQ , which is called
category of quantum observables. Its objects are quantum observ ables S : Bor(JR) � L and its arrows S j e are commutative
the
triangles,
or
equivalently
the
quantum
algebraic
homomorphisms
H : L � K in .C , preserving by definition the join of countable families of pairwise orthogonal events, such that e == H o B in the following
diagram is again a quantum observable.
Bor(.R)
L
H
K
264
CHAPTER S Correspondingly, we may construct a category, denoted by
Os ,
category of Boolean observables. Its objects are the Boolean observables � : Bor(R) � B and its arrows are the Boolean algebraic homomorphisms h : B j> C in B such that B h q in the which is called the
=
,
o
following diagram is again a Boolean observable.
Bor(R)
h
B
c
L is isomorphic with the orthocomplemented lattice of orthogonal projections on a complex Hilbert space, then from von Neumann's spectral theorem the quantum observables are in bijective If
correspondence with the hypermaximal Her1nitian operators on the Hilbert space.1 It is important to note, here, that the original quantum logical formulation of quantum theory depends
in an essential way on the
identification of propositions with projection operators on a complex Hilbert space. A nonclassical, nonBoolean logical structure is thereby induced which has its origins in quantum theory. More accurately, the Hilbert space
quantum
logic has been
initially axiomatized as a
complete, atomic, orthomodular lattice.2 Equivalently, it could be cast as isomorphic to the
partial Boolean algebra of closed subspaces
of the
Hilbert space associated with the quantum system, or alternatively the
partial Boolean algebra of projection operators
of the system? B y
contrast, the propositional logic of classical mechanics is
Boolean logic;
that is, for the propositions of classical mechanics, the class of models over which validity and associated semantic notions are defined is the class of Boolean logic structures. In this setting a fundamental result is provided by the Kochen Specker
theorem,
according
to
which
there are no twovalued
THE QUANTUM TOPOLOGICAL CASE
265
homomorphisms on a quantum logical event algebra L globally. Thus, a quantum event algebra cannot be embedded into a Boolean algebra. Despite this admonition, however, and as stressed in chapter 2, in every concrete quantum m easurement context, the set of logical events that can
always fonns a Boolean event algebra. This fact motivates the assertion that a Boolean algebra within the lattice of quantum logical events plays the topological role of a local logical reference frame relative to which a measurement result is always be actualized in this context
coordinatized. Likewise, together with a logical event structure, there always exists a corresponding probabilistic
structure,
defined by means of convex sets
of measures on that logic. In this sense, the probabilistic structure of a classical system is described by convex sets of probability measures on the Boolean algebra of events of this system; whereas the probabilistic structure of a quantum system is described by convex sets of probability 4 measures on the quantum logical event structure of that system. More accurately, in the case of quantum systems, if the quantum event algebra is denoted by
L,
each
quantum probability measure,
or
quantum
probabilistic state, i s defined by a mapping: p : L + [0, I ] such
that
the
following
p(x v y) = p(x) + p(y) ,
if
conditions
x .l y ,
are
where
satisfied:
x, y
E
L.
p( 1 ) = 1
and
In the Hilbert
space formulation of quantum theory, L denotes the Hilbert space quantum event algebra, whereas a quantum state is defined by the Hilbert
space inner product:
(rp, P xrp) where
x
e
L,
rp i s a normalized vector in the Hilbert space, and
the orthogonal projection operator corresponding to
x
E
L.
Px is
266
CHAPTER 8
8.2
The Topological Significance of Boolean Contexts
The settheoretic axiomatizations of quantum event algebras
the intrinsic topological significance
hides
of Boolean localizing contexts in
the formation of these structures. On the other hand, the operational procedures followed
in typical quantum measurement situations are
based explicitly in the preparation and employment of appropriate
Boolean contexts.
That is to say, even if according to the Kochen
does not exist a global twovalued truthfunctional assignment pertaining to the global event structure of a quantum system, there always exists a local twovalued truthfunctional assignment with respect to a complete Boolean algebra of projection operators on the Hilbert space of a quantum system, identified with a complete Boolean subalgebra of the global nonBoolean event algebra of a quantum system. More precisely, each selfadjoint operator representing an observable has associated with it a Boolean subalgebra Specker theorem there
which is identified with the Boolean algebra of projection operators belonging
to
its
spectral decomposition.
Hence,
given
a
set of
observables of a quantum system, there always exists a complete Boolean algebra of projection operators, viz., a
local Boolean subalgebra
of the global nonBoolean event algebra of a quantum system with respect to which a local twovalued truthfunctional assignment is meaningful, if and only if the given observables are
measurable.
simultaneously
Consequently, the possibility of local twovalued truth
functional assignments of the global nonBoolean event algebra of a
complete Boolean algebras play the topological role of local Boolean logical frames for contextual true/false value assignments. quantum system points to the conclusion that
B ecause of this, we propose a shift in the semantics of quantum events from the settheoretic level to the sheaftheoretic, topologi cal level.
In particular,
the
epistemic path proposed
in this volume
implements the intuitively clear idea of probing the structure of a
THE QUANTUM TOPOLOGICAL CASE
267
quantum algebra of events in terms of localizing Boolean contexts, admitting an unquestionably operational interpretation. quantumtheoretic
localization
process
we
In
describe
this regard, the involves
the
following: First, the introduction of a localization scheme consisting of (local or partial information) Boolean algebras completely covering a quantum
algebra
of quantum events
by
means of coordinatizing
morphisms. These morphisms from the Boolean localizing reference contexts capture, in essence, separate, complementary potential relations, thus providing a structural decomposition or classification of a quantum event algebra i n the descriptive terms of local B oolean reference contexts. These contexts thus provide potentiality windows for the actualization of concrete events via the evaluation or measurement of the observables contextualized. Second, the coherent realization of the quantumtheoretic
localization
process demands the
satisfaction of
partial compatibility between overlapping l ocal Boolean covers. This guarantees
an
efficient
gluing
procedure
between
different
coordinatizations of a quantum algebra of events via the measurement of observables. Third, the qualitative content incorporated in local Boolean reference c ontexts should be integrated globally, such that it respects the requirement of compatibility under both extension from the local level to the global level, and restriction from the global level to the local level.
8.3
Logical Internal Relation : Coherent LocaltoGlobal Ontological Formation
The above three constituent characteristics capture the essence of the sheaftheoretic semantics of a quantum event algebra induced by a localization scheme of B o olean reference contexts. Thus, every local
observable (potential fact) is internally related, via the congruence and compatibility conditions induced by the localization scheme, to a global quantum event structure of actualities. We will now proceed to explain
268
CHAPTER S
how these relations are expressed in terms of covering sieves of quantum event algebras. The mutually implicative internal relation between the local Boolean .
quantum level and the global, partially Boolean quantum level, is formulated m athematically via a sheaftheoretic semantics in tern1s of
covering sieves of a quantum event algebra. This mereotopological, internal relational structure is the mechanism by which local, intra contextual logical implication is both restricted and extended globally, intercontextually. Before defining precisely this concept of covering sieves of a quantum event algebra, it is important to stress the consequences referring to the interpretation of a ' quantum event continuum' via its sheaftheoretic conceptualization. As emphasized earlier, a quantum event continuum is not given as a completed, already
extant settheoretic structure; rather, it is a mereotopological process of continuous ontological formation that unfolds via the punctuated actualization of potential facts with respect to their local Boolean contexts. Most significantly, this process of fortnation is coherent in the sense of respecting the rules of transition from the local or partial to the global and conversely. Moreover, the actualization of any potential fact is an objective augmentation of the already formed global event structure.
The
functional
dependence
inherent
in sheaftheoretic
localization thus relativizes the presupposed rigid relations between quantum events with respect to variable local Boolean contexts
conditioning the actualization of events. In this way, each new actualized event creates a novelly integrated whole, and this is due to the fact that its relational integration to the previously established totality is possible only via gluing and compatibility. It is elucidative to quote Alfred North Whitehead in this respect: The ultimate metaphysical principle is the advance from disjunction to conjunction, creating a novel entity other than the entities given in disjunction. The novel entity is at once the togetherness of the "many" which it fmds, and also it is one among the disjunctive "many" which it leaves; it is a novel entity, disjunctively among the many entities which
THE QUANTUM TOPOLOGICAL CASE
269
it synthesizes. The many become one and are increased by one. In their natures, entities are disjunctively "many" in process of passage to conjunctive unity . . . Thus the production of "novel togetherness" is 5 the ultimate notion embodied in the tenn "concrescence."
Thus, when Whitehead says that the "many become one and are increased by one" this can be interpreted from a sheaftheoretic perspective as follows: The many become one by compatible interconnection or gluing of their relational infonnation content (encompassing the infortnation of the already actualized events in local partiallycompatible contexts), and this process is generative of a novel quantum event; thus, the many are increased by one, because the newly integrated totality now includes this novel event. Together with the compatible local context of this event's actualization, the novel totality, in turn, imposes further compatibility constraints on new local contexts (specified by the requirements of the conjunctive gluing procedure) for the integration of new observable information, and so on. The defining conditions characterizing a sheaf incorporate the formal requirements of this process, wherein every local contextual actualization of a potential fact is internally related to a unique global totality of already actualized facts (events). It is necessary to emphasize that the sheaftheoretic localization of quantum observability is thus conceived as an ontological process and not as a mere epistemic restructuring of a fixed, perpetually extant global totality of quantum events. In this sense it provides a conceptual avenue for a further categorytheoretic investigation of the already established relevance and suitability of Whitehead's process philosophy for the interpretation of quantum 6 m echani cs. For example, a global quantum event algebra, although hypothesized to exist in a way corresponding to reality, is not given as a compl eted whole initially, but has to be formed via actualization of local potential facts with respect to Boolean contexts adding precisely factual content to the global. Furthennore, the bidirectional form of consistent Intern al relation depicted via sheaftheoretic localization reflects the fact that every potential quantum event, actualized with respect to a local •
CHAPTER S
270
Boolean context, is always logically correlated (by means of an equivalence relation) to any other potential quantum event actualized
with respect to any other compatible local Boolean context. Globally,
this means that quantum observables are not determined by their measured values, but by their Boolean observable germs, viz., equivalence classes of compatible Boolean observables forming an inductive limit. Concomitantly, global quantum events are detennined by evaluations of Boolean observable germs.
8o4
Functor of Boolean Reference Frames A
Boolean shaping functor or functor of local Boolean coefficients
of a quantum categorical event structure, event algebras in
M : J3 � .C ,
assigns to Boolean
B (constitutive of a model coordinatizing category) the
underlying quantum event algebras from £ , and likewise assigns to Boolean
homomorphisms
the
underlying
quantum
algebraic
homomorphisms. Throughout the remainder of the discussion, for reasons of simplicity in the notation, the Boolean shaping functor will not appear explicitly in the fo1n1ulas, although it will be always implicitly assumed.
B , then Sets8op denotes the
If Bop is the opposite category of
functor category of presheaves on Boolean event algebras, with objects all functors P : B op � Sets , and morphisms all natural transfo11nations
P in this category is a contravariant setvalued functor on B , called a presheaf on B For each Boolean event algebra B of B , . P (B) is a set, and for each arrow f : C � B , P(j) : P(B) � P (C) is a setfunction. If P is a presheaf on B and p E P(B) , the value P(f)(p) for an arrow f : C � B in B is called the
between such functors. Each object
.
restriction of x along f and is denoted by P(/)(p) p f . The category of elements of a presheaf P , denoted by f(P, B) has as its objects all pairs (B, p) , and morphisms (B',p') � (B, p) are those morphisms u : B' � B of B for which p u p' . =
·
=
·
271
CASE TOPOLOGICAL THE QUANTUM .
f,
Projection on the second coordinate of f(P,B) , defines a functor : J(P, B) � B . f(P, B) together with the projection functor f" is
defined as the split discrete fibration induced by •
P , where
!3 is the base
category of the fibration as in the diagram below. J(P: ,Y.f)
Jp p �>
Sets
We note that the fibers are categories in which the only arrows are identity arrows. If B is an object of B the inverse image under J of B ,
p
is simply the set P(B) , although its elements are written as pairs so as to fonn a disj oint union. The representation or realization functor of the category of quantum event algebras .C into the category of presheaves of Boolean event algebras Sets 80P is defined by:
R : [, � Sets8op The functor of Boolean reference frames of a quantum event algebra L in .C is the image of the representation functor R , evaluated at L , . � Into the category of presheaves of Boolean events algebras Sets13 that ,
IS: •
R(L) := Rr : Bop + Sets Notice that the representation functor of .C is completely determined by the action of the functor of Boolean reference frames, for each quantum event algebra L in .C , on the objects and arrows of the category of Boolean event algebras B , specified as follows: Its action on an object B in
B
is given by
CHAPTER S
272
R(L)(B) := RL (B) = Home (B,L) whereas its action on a morphism x : D � B in
B
,
for v : B � L is
given by
R(L)(x) : Homc (B, L) 7 Homc (D, L) R(L)(x)(v) = v o x It is important to stress that the functor of Boolean reference frames of
a
quantum
event
algebra
L
in
£,
is
a
presheaf
R(L) := RL : Bop � Sets . Thus, we can legitimately consider the category of elements J(R L , E) , together with the projection functor fRL : f (R L , B) � B , viz., the split discrete fibration induced by the functor of Boolean frames of L , where B is the base category of Boolean reference contexts of the fibration. Hence, the functor of Boolean frames of a quantum event algebra induces a uniform and
hor11ologous fibered representation of quantum events in terms of Boolet:fn referenceframes for the measurement of observables. Thus, in mathematical te1n1s, the quantum localization process in the descriptive tertns of Boolean reference frames is understood by means of an action of the category of (local) Boolean event algebras on a set ..
theoretic global structure of quantum events. A global quantum event
algebra is then partitioned into sorts parameterized by the Boolean frames of the base category of local Boolean contexts. In this way, the functioning of a Boolean localization scheme on a global structure of
quantum events is represented by means of a fibered constrUct, understood geometrically, as a locally variable set over the base category of local Boolean reference contexts. The notion of functional dependence incorporated i n this action forces the partially ordered structure of
quantum events to fiber over the base category of local Boolean reference contexts.
It is important to emphasize that the functor of Boolean reference
frames of a quantum event algebra L , viz., the network of relationships
THE QUANTUM TOPOLOGICAL CASE that
L
273
B , formalized as a presheaf, of uniformity among events. By
has with all Boolean contexts
incorporate s the physical requirement
this we mean that for any two quantum events observed over the same Boolean domain of measurement, the structure of all Boolean logical reference frames that relate to the first cannot be distinguished in any possible way from the structure of Boolean frames relating to the second. According to the principle of unifom1ity, in other words, all the localized quantum events within any particular Boolean reference context should be
uniformly equivalent to
each other. The compatibility of the Boolean
localization process of a quantum event algebra with the requirement of uniformity entails that the partial order of relations in a global structure of quantum events is induced by lifting an appropriate family of morphisms from the base category of local Boolean reference contexts to
the partial order of relations among quantum events is induced by corresponding relations among their localizing Boolean reference contexts. the fibers. Equivalently,
8 .5
Functorial BooleanQuantum
Internal Relation The network of relationships defined by a quantum event algebra with Boolean logical frames, formalized categorically by the notion of a presh eaf functor of Boolean frames inducing a Boolean localization sch eme, is the semantic inforn1ation carrier o f a mutually implicative
znternal telation between the •
local Boolean level and the global quantum
leve l . This . dipolar mutually implicative internal relation is formulated in
the category theoretic syntax in tenns of a pair of adjoint functors between the category of presheaves of B oolean event algebras and the category of quantum
adjunctio n.
event algebras, thus
forming a
categorical
This categorical adjunction formalizes the processtheoretic
operation of the category of
transmutation
by relating internally and
274
CHAPTER 8
bidirectionally the local Boolean and global quantum levels of the event 7 structure. More precisely, we forn1ulate the following proposition:
There exists a pair ofadjointfunctors L 1 R asfollows: L : Sets8op
�.> .
£:R
The Boolean framesquantum adj_unction consists of the functors and
R,
L
called left and right adj oints with respect to each other

respectively, as well as the natural b ijection:
Nat(P, R(L)) =: Homc (LP, L) The above bijective correspondence, interpreted functorially, says that the structure
Boolean realization functor
of a quantum categorical event
£ , realized for each quantum event algebra L in £ by its
functor ofBooleanframes, viz., by
R(L) : B � Homc (B, L) has a
left adjoint
L : Sets13op + £ , which is defined for each algebras P in Sets13op as the colimit ( in du ctive
functor
presheaf of Boolean limit):
L(P) = Colim{f(P,B) 4 B � .C} Thus, the fo llowing diagram commutes:
(,_ 2; t'7J
y .,
,,.. ?JI
Ser. B} by noticing that it is naturally endowed with a quantum event algebra structure as follows: [I] The orthocomplementation is defined as:
Q(=ll(lf/s,q)lr= IIClfls,q·) 1
[2] The unit element is defmed as: 1 =11 ({j/s,l) II. [ 3] The partial order structure on the quotient set Y(RL)/t>
S
there
such that the latter biline ar f =g
factorization
linear exists a
such that given any
or
.
Consequently,
factorization via the tensor product of two complex linear spaces H 1 '
H 2 , viz., H I ® H 2
,
should be understood as the universal way to
linearize any bilinear morphism form H 1 linear space
S
.
x
H 2 to any other co mplex
Nate that, since the tensor product construct ion
ts •
defined by a universal mapping property, it is unique up to unique isomorphism.
In
the Hilbert space H = H 1 ® H 2 there exists a special class of st ate
vectors, called product states, which have the product form 'I'
=
'¥ [l] ® \}' l2J
corresponding to the cartesian product of the state vectors of the two subsystems.
But
the
tensor
product
Hilbert
space
H
=
HI @ H 2
FUNCTOruAL ENTANGLEMENT
291
additionally contains all linear combinations of such product states. M ore precisely, if we choose orthonormal bases �(IJa and '¥r2Jb in H1 and H 2 correspondingly, a general vector state of the tensor product Hilbert space H
=
H1 ®
H 2 is written in the following form:
� = L)7ah'f'[l]a @'f'[Z]b ab where the state vector '¥ represents a pure state of the total system composed of subsystems [1] and [2] . We observe that in general, a pure state of this total system is not
red uced to the product of the state vectors of its two subsystems. Thus, it constitutes a correlated or entangl ed state, meaning that each subsystem does not possess a separable state within the composite system. Conceptually, this means that each one of the subsystems of the composite system does not have an individual, separable and definite state independent of the state of the composite system, and most significantly, this is the case irresp ective of the spatial distance between the subsystems. This form of correlation, in other words, is not of any dynamical nature and constitutes a consequence of the universal property
of the tensor product Hilbert space H H 1 ® Hz as a means of linearizing the bilinear morphisms from the cartesian product H 1 x Ii 2 As introduced in chapter 2.8, quantum entanglement in this regard is well =
•
exemplified in experimental EPR correlations, and these will be further analyzed in section 9.4 of the present chapter. The essential aspect of entanglement phenomena is that the behavior of the whole system is not reducible to the behavior of its constitutive subsystems i.e., the whole is more than the sum of its parts; 1 more specifically, the parts do not assume an individuation or localization independent of the whole. Thus there exists a mutually imp licativ e
bidir ectional r elation between the parts and the whole . The observant
reader may have already realized that the general fortnulation of entanglement phenomena lies at the heart of the proposed sheaftheoretic ap proach; and by contrast, the particular case of these phenomena as
292
CH APTE R9
explicated by the nature of the tensor product Hilbert space of states H
=
H 1 ® H 2 constitutes only an
instance
of this general framework of
functorial entanglement, which will be explained later. At this stage, it is instructive to examine the possibility of assigning a notion of
partial state
to each of the subsystems
[1]
and
[2],
even
though neither of these . possesses an individual, separable state. This notion
of
partial
information
about
state
would
thus
encompass
all
the
statistical
Ht that the density operator of the composite system
P12 incorporates. In order to be able to define such a notion of partial state for each of the subsystems
[1]
and
[2]
each one of
and
[2].
By a local action of subsystem
[1]
it is necessary to consider
local actions of [I], for example,
we mean a measurement which can be performed by an observable of subsystem
[1].
This is an operation which is represented by Hermitian
operators of the form
H1
corresponding
A {IJ ® 1 r21, where A[IJ is a Hertnitian operator in
to
the
equivalent to employing a operators
belonging to
chosen observable. Notice
local Boolean frame the
consisting of projection
spectral decomposition of the
observable. Similarly, a local action of subsystem Hetn1itian operators of the fortn 1PJ ® B £21 of the subsystems
[1]
and
that this is
[2]
.
[2]
chosen
is represented by.
We stress the fact that none
have access to all of the observables
(Boolean frames) of the composite system. More concretely, the algebras of observables of the subsystems can be obtained by the operation of
restriction or localization
of the algebra of observables of the composite
system to each one of them. Thus, the individual subsystems subsume the state P12
of
the
only partially. We define the partial state of subsystem [1] as the reduced density operator Pt = Trr.1JP12 obtained by partial tracing over subsystem [2] (and analogously for subsystem (2]) by the composite system
following requirements:
FUNCT ORIAL ENTANGLEMENT
293
Thus, for all observables APJ of subsystem [1], and all observables Bf 2J of subsystem (2], the reduced density operators Pt and p2 correspondingly constitute restrictions of P12 to the respective subsystems. We note that many different states P12 of the composite system may have the same restrictions on the algebras of observables of the two subsystems. Hence, from the point of view of subsystems [1] and [2], many different states of the composite system have identical
restrictions to each subsystem. According to the above requirements, the reduced density operator P1, for example, reproduces the same statistical distribution for an event caused by a local action of subsystem [1] as P1z does, in the sense that we could either apply the operation A Pl ® 1 rzJ on the composite system (thus leaving subsystem [2] unaffected) or apply the operation APJ directly on subsystem [1]. Note that the assumption of considering an event caused by a local action of subsystem [1] leaving subsystem [2] unaffected respects the requirement of Einstein locality in spacetime if the two subsystems are sufficiently separated; in other words, the probability of an event at subsystem [I] is independent of subsystem [2] if the regions associated with these subsystems are space/ike separated. However, it is important to realize that the reduced density operators Pt and P2 are not sufficient to detennine the probabilities of pairs of correlated events between the two subsystems. These pairs of correlated events do not have any dynamical origin but are implied by the entanglement of the states of the composite system if we consider compatible local actions of the subsystems i.e., measurements which can be performed by compatible observables of subsystems [1] and [2]. Equivalently, correlations between events constitutive of the subsystems can be observed with coincidence measurements perfonned between compatible local Boolean frames within some Boolean localization system of the composite system i.e., Boolean frames representing the local measurement contexts of the compatible, correlated observables. The condition of local Boolean frame compatibility between observables of the subsystems [1] and [2] means that the reduced den sity operators p1 and p2 constitute restrictions of some pure state of
294
CHAPTER9
the composite system only if their eigenvalues are identical with respect to these compatible Boolean frames. Equivalently, a vector state of the tensor product Hilbert space
H
=
H1 ® H 2
reflecting the condition of
local Boolean frames compatibility, is written in the following form:
'¥ 2:77 j'¥[1]} (8) 'f'[2] j =
1
where the state vector '¥ represents a pure state of the composite 2 system; \}J[lJ 1, 'f'£ J 1 are orthonorn1al bases of the Hilbert spaces H1 and H2
of the subsystems [1] and [2], respectively, corresponding to the spectral decompositions of P1 and P2 with respect to compatible
Boolean frames of [1] and [2] (or compatible local actions of the two
subsystems); and 1J 1 are the identical eigenvalues of [1] and [2] with . respect to these bases. In the physical state of affairs the correlated pairs of events usually refer to some co nserved physical quantity like charge, energy, ·
momentum or spin orientation of the subsystems (corresponding to some specified observable of the combined system) and persist irrespective of the metrical distance between the subsystems. It is important for the understanding of these entanglement correlations to emphasize the
significance of an event ontology, together with the crucial role that the compatibility betw een lo cal Boo lean fram es (with respect to which events occur by measurement of corresponding observables) plays, in
Boolean localization systems. This is the case because entanglement correlations canno t be reduced to correlations between assumed pre existing states assigned to the subsystems before the occurrence of the events (with respect to their corresponding local Boolean frames). Thi s •
conclusion reaffirms the significance of Whitehead's event ontology tn the relational realist understanding of entanglement correlations rn quantum theory. •
F UNCT ORIAL ENT ANGLE MEN T
92
295
Functorial Entanglement The ontological significance of events in interpreting entanglement
phenomena forces a careful rethinking of the notion of a subsystem of a composite system as exemplified by the concept of a partial state, or reduced density operator pertaining to its description. Since a partial state of a subsystem is used for the evaluation of probabilities of the events referring to this subsystem exclusively, irrespective of any correlations of these events with events referring to any other subsystem, it becomes clear that:
not fundamental and retains meaning only insofar as a complete Boolean frame is designated. This [i] The notion of a subsystem is
frame corresponds to the measurement of some observable via the registration of some corresponding fact interpreted as an observed event. Hence, the notion of a subsystem before the existence of some observed events remains only as a
potentiality expressed by its partial state
description. This potentiality, under the designation of some Boolean frame, acquires the interpretation of a
probability function for the
evaluation of eventprobabilities when the subsystem is definable as a reference linkage among observed events referring to the corresponding observable. [ii] The separation of a composite system into subsystems is an
idealization; it does not correspond to a 'partition' of the system into subsystems in tern1s of the density operators by which the subsystems are described. Rather, it is properly understood as the
algebraic operation of restriction or localization of the algebra of observables of the composite system into appropriate subalgebras of observables corresponding to potential subsystems which can be realized only after the designation of local Boolean frames. Intuitively, these subalgebras represent only the observables subsumed by the potential subsystems, distinguished in this Way only after
the
generation of
concrete
measurement events.
Furthermore, this observablesinduced distinguishability of subsystems Within a composite system, for example of the subsystems [1] and [2] according to the preceding, is effectuated by considering observables of
296
CH APTER 9
the form A [IJ ® 1 r21 and 1 Pl ® B £21 within the algebra of observables of the total system. [iii]
The
observablesinduced
distinguishability
of
potential
subsystems within a composite system allows for an understanding of entanglement correlations between these subsystems under the condition of
compatibility
betvveen their corresponding local Boolean frames
within the Boolean localization system of a composite system. For example, in the case of two potential subsystems, the condition of compatibility means that the reduced density operators
Pt and P2
constitute restrictions of some pure state of the composite system only if their eigenvalues are identical with respect to these compatible Boolean frames. Reflecting on the above, we conclude that the notion of entanglement or nonseparability pertaining to the description of a composite quantum system in tertns of its potential parts
intrinsic relativity with compatible local Boolean frames distinguishing the
terms of the· system as a whole respect to the
subsystems
and the description of the parts in implies an
and their correspondingly compatible observables. In this
way, it becomes clear that the same pure state of a total system may. entail completely different entanglement correlations depending on the
choice
of different sets of local Boolean frames. Thus, it is important to
formulate the notions of entanglement and nonseparability functorially. This means that we need a functorial framework to properly expres s entanglement correlations among potential subsystems of a composite system which are
observableinduced
and
choices of subsystems. For this purpose
fibration
do not depend on artificial the sheaftheoretic uniform
partitioning a general quantum event algebra into observable
sorts, indexed by local Boolean frames and thus for1ning Boole an localization systems, is indispensable. As the discussion proceeds, we will show that the sheaftheoretic
inductive limit
construction of
a
quantum event algebra with respect to some Boolean localization syst em
tensor product decomposition, providing a general functorial formulation of entanglement phenome}za from the sheaftheoretic perspective of our approach. can be expressed in terms of a functorial
297
FUNCT ORIAL ENT ANGLEM ENT
It was shown in chapter 8.7 that a general quantum event algebra
L
isomorphically by the inductive limit taken in the category of local Boolean frames of the sheaf R L with respect to a Boolean is represented
localization system:
L = Colim{f(RL,B)� B} := ColimRL = LRr The functorial tensor product decomposition is obtained by expressing categorically the above colimit (inductive limit) as a
coequalizer of a
coproduct. For this purpose, we consider the colimit of any functor X: I+.£ from some index category I to £. Let fLi : X(i) * lljX(i), i E I, be the injections into the coproduct. A morphism from this coproduct, x: lljX(i)+ £ is deterxnined uniquely by the set of its components xi = XJli These components x' fonn a cocone over X to the quantum event algebra vertex L only when for all arrows v : i � j of the index category I the following conditions are satisfied: ,
.
X(i) J.l;
U X(i)
X
·
· ·· · · · ·
· ··· · · ·
·)
L
X(j) (XJ.LJ )X(v) = XJ.L; So we consider all X(domv) for all arrows v with its injections p.., and obtain their coproduct Ilv +1X(domv). Next we construct two arrows ( J
298
CH APTER 9
and 17, defined
in terms of the injections
f.Li, for each
P,v and
v:
i 4 j
by the conditions:
together with their coequalizer
X:
X(i)
X(dornv)
•
..
• •
f..Li
•
•
•
•
•
·· XP.i .
.
•
•
•
•
• • • •
•
s
'
17
�
The form a
•
� >
� UX(i)······· ···
. .
.
•
::J
�
L
coequalizer condition xs = X'TJ inforins us that the arrows XJL; cocone over X to the quantum event algebra vertex £ We .
further note that since
x
is the coequalizer of the arrows ( and 7] this
colimiting cocone for the functor X: I + £ from some index category I to £. Hence the co limit of the functor X can be constructed as a coeq ualizer of coproduct according to the following cocone is the
diagram:
UXU)
�
'
X

>Colin1X
In our case the index category is the category of elements of the presheaf of Boolean algebras
M J(P, B) o
P, that is
plays the role of the functor
f(P,B),
X: I+£.
and the functor In the diagram
FUNCTORIAL ENTANGLEMENT
above, the second coproduct is over all the objects
299
(B,p) with p E P(B)
of the category of elements, while the first coproduct is over all the maps
v: (B', p') � (B, p) of that category, so that v: B' � B and the condition p v = p' is satisfied. We conclude that the colimit L M (P) can be ·
equivalently presented as the following coequalizer of coproduct:
s
J t
. .. 
.,_.,
:) )
The preceding is referred to as the
functorial tensor product
decomposition of the colimit (inductive limit) in the category of elements of
P
induced by the shaping functor of local Boolean frames
M of a
quantum categorical event structure. In order to understand the induced tensor product decomposition semantics in functorial terms, we ignore for the moment the quantum algebraic structure of the category £, and we simply take ,C = Sets
. Then the coproduct liPM(B} is a coproduct of sets, which is equivalent to the product P(B) x M(B) for B E B. The coequalizer is thus the definition of the tensor product P @B M of the set valued functors:
P :Bop� Sets,
M:B �sets
p E P(B) , v: B' 4 B and q' E M(B') the following equations hold, symmetric in P and M:
According to the above diagram for elements
((p,v, q') = (p . v, q'), Hence the elements of the set
r;(p, v,q') = (p, v(q'))
P ® 8 M are all of the form z(p, q) ,
which can be equivalently written as:
X(p, q) = p ® q,
p E P(B), q E M(B)
CHAPTER 9
300
Thus if we take into account the defmitions of s and
7J above, we
obtain:
p·v ® q'= p ® v(q'), pEP(B),q'EM(B'),v : B' � B P ® s M is actually the quotient of the set equivalence relation generated by the above
We conclude that the set
U8P(B)xM(B)
by the
equations. Furthermore if we define the arrows
ls:P(B) � Homc(M(B),L) they are related under the Boolean framesquantum adjunction by:
BEB,pEP(B), qEM(B)
ks(p,q) = ls(p)(q), k as a function ks:P(B)xM(B) � L satisfying
Here we consider
on
Il8P(B)xM(B)
with components
ks'(P·v, q') = ks(p,v(q')) in agreement with the equivalence relation defined above. Now we replace the category algebras
Sets
by the category of quantum event
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INDEX Abstract
(Modern)
Differential
Geometry (ADG), 3 8 1 84 actualities/actualization:
metrical
relations,
8085; of
universe, 1 1
Boolean
actual occasions: quantum mechan
logic and quantum mechanics
ics and, 16368, 2029; topo
theory
logical localization and genetic
and, 435 1 ;
category
and, 1 1 932; compatibility con
analysis, 3 3334
dition and, 5863, 14856; EPR
adjoint factors : Boolean topological
and decoherence, 1 06 1 0; im
s ignificance, 26667; category
plicate order of, 9; internal lo
theory and, 22932; functorial
caltoglobal
for
Booleanquantum internal rela
internal
tion, 27477; localization theo
mation,
ontological
26970;
relation and, 525 8, 1 40 47; lo cal to
global
transformation,
6368; logically related actual
ries, 36264 adjunction: category theory, 223; partial congruence and, 32830
occasions, 1 6 869; mutual im
AharonovBohm effect, 2 1 5 1 6
plicative relata and, 78, 242 6,
algebra:
decoherence
analysis.,
1 6368; of physical state, 1 5
34045 ; differential extensive
1 6, 3 337; of potentia, 3435;
connection, 37884; functorial
potentialtoprobable evolution,
entanglement, 295303 ; White
15763 ; quantum events inter
head's discussion of, 1 2032
pretation,
3057;
measurements,
quantum
xvixviii,
37
angular momentum, EPR and quantum nonlocality, 7 1 80
3 8 ; quantum nonlocal ity and,
aphairein (Aristotle), 22832
7 1 80; relational realism and,
Aristotle, 5, 8687, 1 80, 33334
8695, 133, 2029, 34752; self
arithmetization, localization theo
reference prob I em, 1 1 3 1 5 ; set theory/sheaf theory semantics and,
25557; topological
vs.
ries, 21316 arrowtheoretic formulation: arrow reversaL. 228; category theory, 222
INDEX
400 assimilation: fa1 1acy of misplaced concreteness and, 1 32 1 ; mutu
pretation, 3037 Boolean germs, 1 94; decoherence
ally exclusive relata and, 1 2 asymmetrical relationships:
300303; quantum events inter
com
33745 ;
and,
entanglement,
patibility condition for logical
EPR correlations, 3 1 1  1 3 ; ex
causality, 5 863; internal rela
tensive connection theory and,
tions
in
37276;
and,
14047;
quantum
mechanics of
philosophy
mathematics and, 1 1 92 1 , 1 3032;
quantum
mechanics
and
localization systems,
2798 1; local quantum events and,
2069;
events
classification,
mereotopology
Boolean logic and, 44 5 1 atomic topology, category theory
measurement and,
32326; 1 8790;
quantum events interpretation, 3 047; quantum logical event
and, 22 122
algebras and observables, 26 1 Bacon, Francis, 30
65; relational realism and, 349
base categories, localization topol
52; topological relations, 26184; truth valuation, Boolean lo
ogy and, 23540
calization system, 32 1 �23
B erry phase, 215 1 6 bipolar dualism: mutually exclusive
B o olean localization system: clas sical
ism and, 327; scientific meth
3303 2; decoherence and, 334
od and, 1 012
. 45;
to
transition,
relata and, 51 0 ; relational real
quantum
epimorphic
family
for
B ohm, David, 81 0
mation, 2798 1 ; truth valuation,
B ohmHiley nonlocal hidden vari
3 1 823
ables, quantum mechanics and, 9 1 0
B oolean logic: categorysheaf theo ry and, 200209; compatibility
.
Bohm's correlations, entanglement,
condition for Io gical causality and, 5963, 14956; composite
307 1 3 Bohr, Niels, 1 1 1  1 5, 34647; com
system entanglement, 28894;
plementarity principle of, 57
dipolar duality and, 23; dipolar
Boolean algebra, 26 165, 32728 Boolean cover, physical contexts,
quantum units, 1 6368; functo rial entanglement, 295303;
quantum localization, 32728
functor of Boolean reference
Boolean framesquantum adjunc
frames, 27073; global induc
.
tion:
functorial
entanglement,
tion from local conditions, 6368; internal relations and, 52
INDEX
40 1
58, 1 40 47; local Boolean ref
Bub, Jeffrey, 1 06
erence frames, gluing isomor
B uraliForti paradox, 1 17 1 9
phism,
2 8 1 84;
local ization,
2 141 6, 2798 1 ; objective local
candidate probability, decoherence,
contextuality and, 3943; poten tialityprobability evolution and,
33945 canonical inj ections, category theo
1 5 863; quantum event classifi
ry, 226 .
cation, 3 1 3 1 7 ; quantum locali
Cartesian
coordinates,
quantum
zation, sheaf of Boolean refer
mechanics and B oolean logic
ence frames, 27779; quantum
and, 475 1
mechanics and, 435 1 ; refer ence frame, sheaf localization, 27779; relational realism and,
Cartesian dualism, relational real ism and, 5 categorical topology:
localization
9295, 34652; self reference in
and, 23540; quantum observa
quantum mechanics and, 1 1 1
bles, 26365
1 5 ; separation of science from,
categories, properties of, 223
3239; topological localization,
categorysheaf theory, 6468; EPR
23640; truth valuation, locali
experiments and, 99n46; exten
zation systems, 3 1 823; White
sive relations and, 1 9294; mer
head's philosophy of mathemat
eotopology and, 1 8590; phi
ics and, 1 2632
losophy of mathematics and,
Boolean
measurement
context:
1 2632;
quantum
mechanics
EPR and decoherence and, 1 07
and spacetime and, 8385; rela
1 0; fallacy of misplaced con
tional realism and, 1 99209
creteness and, 1 52 1 ; predica
category
theory:
conceptual
tion in quantum mechanics and,
framework for, 22032; exten
1 034;
sive
quantum
theory
and,
•
XVIXX
Boolean realization functor, 27477
connection
theory
and,
1 8590; mutual relations and transformations, 22022; partial congruence
and
adjunction,
Borel algebra, 26365
32830; principles of, 12732,
Born's rule: compatibility condition
22227; process
metaphysics,
for logical causality and, 6063;
356; terminology, 22227; uni
quantum mechanics and Boole
versality and equivalence in,
an logic and, 435 1
22732
B oyle, Robert, 30
Cauchy sequence, 1 8084
INDEX
402 causalphysical pole, 1 1 920, 1 3 1 32
commutativity: decoherence, 34045 ;
causal relations: decoherence and, 6870; EPR and quantum non
quantum
mechanics
and
Boolean logic and, 455 1 compatibility condition for logical
locality, 7580; oneway effi
causality:
entanglement,
ciency in, 1 98 n l 3 ; predication
correlations, 309 1 3 ; functorial
EPR
and,
entanglement, 296303; internal
1 045; relational localization,
localtoglobal ontological for
36672
mation, 26770; quantum me
in
quantum
Classical
mechanics
Differential
Geometry
(CDG), 3 8 184
complementarity: fallacy of mis
classical physics: decoherence and, 3 3545 ;
localization
theories
and, 2 1 3 1 6; quantum mechan ics and, 35660; quantum theo ry
and,
xivxx;
reference
frames, 33032 germ
placed concreteness and, 1 32 1 ; mutually exclusive relata and, 68 composite systems, entanglement and, 28794 conceptual inverses, category theo
classification: measurement events, Boolean
chanics and, 5863, 1 4856
ry and, 22932
classification,
concrescence: philosophy of math
32326; quantum events, 3 1 3
ematics and, 1 3 334; potentiali
1 7 ; truth valuation, Boolean lo
typrobability
calization system, 3 1 823
1 5763; relational realism and,
coarsegraining: decoherence, 33545; relational realism, 3 5 1 52 c·ocones, category theory, 225 coequalizer
condition,
functorial
8995, 35052� set theory/sheaf theory semantics and, 25557 system entanglement, 28994 congruence: internal localtoglobal
coherence, dipolar duality and, 2327
ontological formation, 26770; partial
coincidence measurement, entan glement, EPR correlations, 3 1 013
congruence,
32830;
topological localization and ge netic analysis, 33334 consistent sets, 33945 ; decoher
category
theory,
226;
functorial entanglement, 298303
and,
conditional probability, composite
entanglement, 297303
co limits:
evolution
ence and, 34045 contextual
dependency:
internal
relations in quantum mechanics, 1 4347;
measurement events,
403
INDEX B oolean
germ
classification,
decoherence: Boolean localization
3 2426 ; sheaf germs and stalks,
and, 3 34 45; causal relation and
2485 1
logical
integration,
6870;
contextualized measurement: inter
compatibility condition for logi
nal relations and quantum me
cal causality and, 1 5 1 56; histo
chanics and, 5458 ; quantum
ries, 1 9; localization theory and,
mechanics and Boolean logic
2 1 5 1 6; potentialityprobability
and, 475 1 ; relational realism
evolution and, 1 5 963; predica
and, 9295
tion in quantum mechanics and, 1 05 1 0; relational realism, 3 5 1 
continuity, in quantum theory, xiv xx
52 .
coordinate division, 1 9697
Dedekind real numbers, set theo
coordination, localization theories,
ry/sheaf theory semantics, 254
2 1 3 1 6
57
Copenhagen Interpretation, 1 1 21 6 correlation events:
density matrix: decoherence and,
entanglement,
1 6062, 334 45; offdiagonal
EPR correlations, 308 1 3 ; topo
terms in, 98n34, 1 1 0, 1 52, 1 59,
logical localization and genetic
1 7 1 72; PNC violations and,
analysis, 3 3334
98n34, 1 0 l n.65, 1 07
cosmology: bipolar dualism and,
density operator, composite system entanglement, 28794
1 0 1 2; dipolar duality and, 2427; fallacy of misplaced con
De
Rham's
algebraictopological
creteness and, 142 1 ; relational
theory,
realism
connection, 37884
and,
8695;
White
representational
extensive
Descartes, Rene, 5
head's essay on, 23 covariant
differential
factor,
category theory, 23032
detectors: compatibility conditions and, 14856; Copenhagen for
covering sieve: B oolean germs and
malism in,
1 1 4; dipolar unit
extensive connection, 37576;
quantum events, 1 6368; dou
localization topology, 23540;
bleslit
mereotopology
and,
1 8789,
95n4,
experiments� 14445,
3334,
1 4547; envi
1 9394; relational localization,
ronmental relations, 6970; in
36972; representable functors
dexical eventuality in, 1 5 863 ;
as, 25759
local relations, 606 1 ; logically
covering sites, localization topolo gy, 23340
related actual occasions, 1 6873 ; nonlocal relations� 62, 7 1 
INDEX
404 80; objective local contextuali ty, 3 940; orthonormal basis for,
1 9293 ; predication and,
eigenvalues/eigenstates,
quantum
measurement and, 1 34n 1 Eilenberg, Samuel, 1 27, 1 8284
. 1 09, 1 33, 1 42; quantum meas
Einstein, Albert: field equations,
urements, 3 335 ; relational re
3 65; theories of, xiv, 1 97n4
alism and, 8 895; self reference
Einstein,
Podolsky
and
Rosen
in quantum systems and, 11 1 ;
(EPR) correlations: compatibil
topological
ity condition for logical causali
vs.
metrical rela
tions, 8285
ty and, 6263; experimental ar
diagrams, category theory, 225
rangements
for,
99n44;
differential extensive connection,
functorial entanglement, 3071 3 ; internal relations in quan
37684 dipolar duality: functorial Boolean
tum mechanics and, 55, 1 44 47;
quantum internal relation, 273
predication in quantum mechan
77� mutually implicative relata
ics and, 1 05  1 0; quantum non
and, 2227; predication and,
l ocality
1 1 932; relational realism and,
99n44;
35 152
35760; relational realism and,
discreteness, in quantum theory,
and,
7 1 80,
quantum
98n40,
theory
and,
99n46; spin systems, 2049 Eleatic School, 8 1 0
•
XIVXX
disjoint relations: Boolean germs
elementary objects: quantum me
and extensive connection, 372
chanics and spacetime and, 8 1
76; EPR and quantum nonlocal
85 ; unifonn localization of ob
ity, 77 80; quantum mechanics,
servables, 244 46; Whitehead's
525 8 ; sheaf germs and stalks,
philosophy of mathematics and,
2495 1; uniform localization of
1 25
observables, 24546
empirical adequacy, dipolar duality
dissipative energy transfer, compat ibility condition for logical cau sality and, 15 156 doubleslit
experiments,
empirical
3334,
dua.lity, quantum events interpreta
empiricism,
dipolar
mutually
exclusive
relata and, 1 2 entanglement: composite systems and, 28794; EPR correlations, 307 1 3 ;
Eddington, Arthur, 23740
applicability,
duality and, 2327
95n4, 1 4547 tion, 3057
and, 2327
functorial
entangle
ment, 295303; quantum events
405
INDEX interpretation, 3037; quantum
extensive connection theory, 1 8590; B oolean germs and, 37276;
theory and, 35760
See
classical to quantum trans ition,
also systemenvironment rela
332; localization topology and,
tions: B oolean localization and,
234 40;
33545 ; compatibility condition
1 9094; quantum gravity appli
for logical causality and, 1 5 1
cations, 37684; relational lo
56
calization,
decoherence.
environmental
Boolean
family
formation:
localization
3 6772;
and,
relational
realism and, 1 9496, 34952
Epimenides paradox, 2 1 ., 3 1 epimorphic
mereotopology
systems
external objects, category theory and, 22832
and germs, 2798 1 ; gluing iso morphism, local Boolean refer
fibration: functor of Boolean refer
ence frames, 28 184; reference
ence frames, 27273 ; split dis
frame, sheaf localization, 277
crete fibration, 24546; uniform
79
methodology, 23233
equalizers, category theory, 22627
finegraining, decoherence, 33 845
equivalence: category theory, 227
formalism, limitations of, 1 2032
entanglement,
functions: category theory, 22732;
3 00303; quantum events inter
uniform fibration methodology,
32;
functorial
pretation,
3057;
uniform
equivalence, fibration method
2323 3 functorial tensor product composi tion, 299303, 3 1 0 1 3
o logy, 23233 erasure procedure, doubleslit ex
functors: Booleanquantum internal
periments, 1 4547
relation, 27377; Boolean refer
Euclidean space, 37784
ence frames, 27073, 27779;
Everett, Hugh, 8, 42
composite system entanglement,
Excluded Middle, Principle of. See
2 9 1 94;
covering
sieves
as,
Principle of the Excluded Mid
25759; entanglement in, 295
dle (PEM)
303� quantum events interpreta
exclusive disjunction: Boolean log ic and, 48, I 35n 1 1 ; outcome
tion, 3037; subobject functor, 3 1 4 1 7
states, 4 1 , 5 1 extensive abstraction theory, 17980;
categories
23540
and,
22832,
Gelfand topological representation theorem, 3 3745 generalized records, 3 3 945
INDEX
406 genetic analysis: coordinate divi
internal localtoglobal ontolog
sion and, 1 9697, 208; internal
ical formation, 26970; isomor
relations and, 5258, 1 7374,
phism, local Boolean reference
1 7984; mereotopological ex
frames, 2 8 1 84; local Boolean
tensive relations and, 1 9295;
reference frames, 2 8 1 84; local
philosophy of mathematics and,
ization theories and, 2 1 5 1 6;
1 202 1 , 1 3 1 , 1 39; topological
localization topology and, 234
localization and, 33334
40; mereotopology and, 2039;
global relations: compatibility con
process
metaphysics, 35556;
dition for logical causality and,
relational localization, 3 6972
6063 , 1 4856; dipolar quan
Godel, Kurt, incompleteness theo
tum units and, 1 636 8 ; global tolocal
compatibility,
gluing
operations, 24648; internal re
rems of, 1 8 1 9, 3 1 , 1 24 Griffiths, Robert, 1 5356 Grothendieck
topology,
6468;
localization
systems
lations and quantum mechanics
Boolean
and, 545 8 ; local contextuality
and germs,
and, 6368, 14347; mereoto
sieves,
pology and, 1 8790; potentiali
33745; differential extensive
typrobability
and,
connection, 3 8084; functorial
1 5 863 ; predication in quantum
Booleanquantum internal rela
mechanics and, 1 045; self ref
tion, 27677; gluing isomor
erence in quantum mechanics
phism, local Boolean reference
and, 1 1 2 1 5 ; sheaf theory and,
frames,
34852; uniform localization of
and, 23540; local topological
observables, 244 46
region and, 20 19; quantum lo
evolution
2798 1 ;
25859;
2 8 1 84;
covered
decoherence,
localization
globaltolocal transformation: ac
calization, sheaf of Boolean ref
tualities, 6368; genetic analy
erence frames, 27779; quan
sis and, 3 3334; gluing opera
tum mechanics and spacetime
tions, 24648; internal relations,
and,
26970;
sheaf localization, 27779; rela
quantum nonlocality,
7 178 ; relational realism, 35 1
8 185; reference frame,
tional realism and, 9095
52 gluing axiom,
6768 ;
category
sheaf theory, 1 94; classical to quantum transition, 332; global tolocal compatibility, 24648;
Hartle, James, 1 5 Hausdorff topological spaces, 3057 Hawking, Stephen, 1 5
INDEX Heisenberg, Werner, 1 3 3 , 1 3 7n52, 1 60
407 mathematics
idempotency:
and,
12932; relational localization,
Heisenberg uncertainty relations,
36672 identity, mathematics and, 1 2932
3 6572 Henry, Granville, 12627, 129
implicative
relations:
EPR
Heraclitus, 56, 22
quantum
nonlocality,
hidden variables theory, quantum
quantum mechanics, 525 8
and
7780 ;
incompleteness, Goders theorems
mechanics and, 9, 104
of, 1 8 1 9 , 3 1 , 124
Hilbert, David, 47 Hilbert space formalism: compati
inductive limit: Boolean local iza
bility condition for logical cau
tion systems and germs, 279
sality and, 1 4956; composite
81;
system entanglement, 28794;
296303 ; globaltolocal com
objective
contextuality
patibility, 6468 ; partial con
and, 3943; quantum mechanics
gruence and adjunction, 3 30;
and Boolean logic and, 465 1 ;
sheaf germs and stalks, 2485 1 ;
quantum observables, 26465;
truth valuation, Boolean locali
relational realism and, 1 9496
zation system, 3 1 823
local
histories: of actual occasions, 2526, 35, 1 6468, 1 8794; deco herence, 33745; of decoher ence, 1 9, 1 5256; of facts, 7475,
1 33,
15962; predication
and, 1 1 5; of quantum events,
entanglement,
infinitesimal differentiability, 3 8 1 84 infinitum actu non datur (Aristo tle), 1 80 information carriers, relational lo calization, 36972 information classification, partial
2068 homomorphisms: category theory, 22732;
functorial
functorial
ment, 3013;
entangle
quantum event
classification, 3 1 417; quantum
congruence
and
adjunction,
32830 ingression, category theory and, 22832
logical event algebras and ob
interference fringe/effect: decoher
servables, 26 165; sheaf germs
ence, 33545 ; quantum super
and stalks, 2505 1
position and, 3 339 internal relations: category theory
idealization,
functorial
ment, 295303
entangle
and, 12732; covering sieves as representable functors, 25759; elemental
units
of,
1 1 920,
INDEX
408 EPR
Kaehler's theory of generation, dif
correlations, 3 1 0 1 3 ; functorial
ferential extensive connection,
Booleanquantum internal rela
37884
1 3234;
entanglement,
tion, 27377; global induction
Kant, Immanuel, 1 2
from local and, 636 8 ; localiza
Kauffman, S tuart, 93
tion schemes and, 2 1 9 ; localto
KochenSpecker theorem, 5658,
formation,
64 6 8, 1 34n3; localization to
26770; logical asymmetry in,
pology and, 23640; predication
1 98nl3 ;
in
global
ontological
mereotopology
and,
quantum
mechanics
quantum
and,
1 8590; potentialityprobability
1 034;
localization,
evolution and, 1 5763 ; quantum
3 6364; quantum observables,
mechanics and, 5258, 1 4047;
26465; relational realism and,
relational realism and, 9295
2029
intrinsic relativity: B oolean germs and extensive connection, 373
Leibniz, Karl, 59
76;
Leonard, Henry, 9 193, 1 20
functorial
entanglement,
Lewis, David, 4243
296303 isomorphisms:
canonical isomor
phisms, 22829, 249; functorial
local
B oolean
frames,
28 1 84;
quantum theory and, 35764; .
entanglement, 296303; gluing,
relational realism and, 34752
local B oolean reference frames,
localization: Boolean covers and
28 184; natural isomorphisms,
physical
224, 2303 1 ; partial congruence
Boolean
systems
and gern1s,
and adjunction, 32930; quan
2798 1 ;
Boolean
topological
tum topology, 27577; relation
significance, 26667; category
al realism and, 34852; set the
theory and, 22032; classical to
ory/sheaf
quantum
theory
semantics,
25357; sheafification, 253
contexts,
32728;
transition,
33032;
decoherence, Boolean localiza tion and, 3 34 45; differential
joint probability distribution, com posite
system
entanglement,
extensive connection and, 37784;
functorial
295303; genetic analysis, topo
28794
logical Kaehlerde
entanglement,
Rharm
homological
mechanism, 37884
localization,
33334;
measurement events; Boolean germ
classification,
32426;
partial congruence and adjunc
409
INDEX tion, 32830; in physical theo
EPR and quantum nonlocality,
ries, 2 1 31 6; quantum events
7 180; logically related actual
3067;
occasions, 1 6869; mereotopol
quantum mechanics and, 360
ogy and, 1 8590; potentiality to
64; relational sheafbased theo
probability evolution,
ries, 36472; schemes for, 2 1 6
predication and, 1 05; quantum
1 9; sheaf of B oolean reference
logical event algebras and ob
frames, 27779; sheaftheoretic
servables, 2 6 1 65; in quantum
quantum
mechanics, 5863, 1 3 972; re
3037,
interpretation,
relational
realism,
34552; topological space, 24344; topology and, 23340; truth valuations in, 3 1 823 ; uniform fibration methodology, 2323 3 ; uniform o bservables
localiza
tion, 244 46 tion for logical causality and, of, and,
1 4856;
3943;
lational localization, 36672 logicalconceptual
pole,
1 1 920,
1 3 132 logical
integration,
decoherence
and, 6 870 logical structure, dipolar duality
local relations: compatibility condi 6063,
1 5763;
contextuality
compatibi lity,
l ogical types, theory of: philosophy of mathematics and,
I 1 932;
conditions
quantum mechanics and, 1 I 6
globaltolocal
19; settheoretic framework for,
global
6368 ;
and, 2327
gluing
opera
1 8284
tions, 24648; mereo to polo gy and, 1 8790; uniform localiza
Mac Lane, Saunders, 127, 1 8284
tion of observables, 244 46
macroscopic superposition, 3239;
localtoglobal transformation: ac
decoherence, 33545
tualities, 6368; genetic analy
Mallios, Anastasios, 3 8 1 84
sis and, 33334; gluing opera
Many
Worlds
Interpretation
tions, 24648; internal relations,
( MWI), objective superposition
26970; quantum nonlocality,
of states and, 89, 3943
7 1 78; relational realism, 35 152 local topological region, defined, 200209 causality:
Founda tions of Mechanics (von
Neumann), 1 1 2 1 5 mathematics: mereotopology and,
Locke, John, 5 , 1 2, 59 logical
Mathematical Quantum
1 7984; philosophy of, 1 82 1 , compatibility
condition for, 5863, 1 4856;
1 1 932;
process
and, 35456
metaphysics
INDEX
410 ''Mathematics
and
the
Good"
mutually exclusive relata: bipolar dualism and, 5 1 0 ; cosmology
(Whitehead), 1 20, 1 22
1 0 12; fallacy of mis
maximal sieves, 25859
and,
Mazzola, Guerino, 23 132
placed concreteness and, 1 32 1
measurement: Boolean germ event classification, 32326; localiza tion
topology
and,
23640;
mutually implicative relata: com posite
system
2 9 1 94;
entanglement,
dipolar duality
and,
quantum actual occasions, 170
2227; dipolar quantum units,
73; quantum mechanics and _ B oolean logic and, 455 1 ; in
1 6368;
correlations, 308 1 3 ; functorial
quantum theory, xiiixx, 1 34n 1
B ooleanquantum internal rela
mereotopology: compatibility con
entanglement,
EPR
tion, 27377; internal localto
dition for logical causality and,
global
1 4856; extensive relations in,
26870; relational realism and,
1 9094; global induction from
209
ontological
formation,
local and, 6568; internal rela tion and logical implication in, 1 8590; logicalextensive rela tion
integration
quantum
in,
1 7996;
mechanics
and
spacetime and, 8285 metrical
relations:
quantum
to
33032;
EPR and quantum nonlocality,
isomorphisms,
category
theory, 22324, 23032 natural philosophy, EPR and quan tum nonlocality, 7 680 natural
classical
transition,
natural
transformation,
category
theory, 22227 Nature Uournal), 3234 negative selection, 8 889, 1 079;
7580; quantum mechanics and
integration
spacetime and, 8085; relational
1 2 829; internal relations, 1 7 1 
realism and, 8995
7 3 ; logical causality and, 1 5 1
microscopic observables, decoher ence, 33645
and,
5 3 ; potential relations and, 1 6 1 62;
misplaced concreteness, fallacy of,
of relations
transmutation
mechanism
and, 1 6263
.
1 32 1 mixed state, composite system en tanglement, 28894
nested composite inclusions, cover ing sieves as representable func tors, 25759
Mobius strip, 6768
New Organon (Bacon), 30
momentum, bipolar dualism and,
nondissipative decoherence, 152
67
56
41 1
INDEX See
nonlocality.
quantum
non
locality: quantum events inter
open neighborhoods,
topology and, 23740 operational
pretation, 3047 nonseparability, EPR correlations, 307 1 3
local ization
procedures,
category
theory, 22 122 orthogonal
projections,
quantum
observables, 26465 objective indeterminacy, 3943
overlapping
relations:
EPR and
objective local contextuality, 3 943
quantum
objective superposition of states,
quantum mechanics, 525 8 ; re
4043
nonlocality,
7780;
lational localization, 3 6972
objects and relations, quantum the ory and, xivxx
Parmenides, 56, 89, 22
observables: decoherence, 33545; entanglement, EPR correlations, 308 1 3 ; ment,
functorial 295303;
entangle localization
theories, 2 1 3 1 6; quantum logi
partial Boolean al gebra, 26165 partial
states:
composite system
entanglement., 29294; functori al entanglement, 295303 partitioning:
functor of Boolean
cal event· algebras and observa
reference frames, 27273; uni
bles, 26 165; quantum mechan
form
ics
23233
and,
35860;
relational
localization, 36572; set theo ry/sheaf theory semantics and, 25457;
uniform
localization,
244 46
fibration
phenomenon,
methodology,
relational
and, 34652 physical context, Boolean covers, quantum local ization, 32728
"Of the Excellency and Grounds of
physical continuum: category theo22022;
localization
the Corpuscular or Mechanical
ry,
Philosophy" (Boyle), 30
schemes and, 2 1 6 1 9
Omnes, Roland, 3843, 9095 onedimensional projectors, com posite
system
entanglement,
28 894 "On Mathematical Concepts of the Material World'� (Whitehead), 1 25 On the Plurality of Worlds (Lewis), 4243
realism
physics, localization theories, 2 1 316 Plato, 5, 1 7 1 8 ; Protagoran doc trine and, 303 1 Platonic dualism, relational realism and, 5 Podolsky, B . See
Einstein, Po
dolsky and Rosen (EPR) corre lations
INDEX
41 2
Poincare, Henry, 2 1 6
40; mereotopology and, 1 89
pointer basis, 335
94; relational localization, 369
positivism, relational realism and,
72; uniform fibrations method ology, 23233; uniform locali
9 1 95 potentia: category theory and, 22832; causal relation and logical integration,
6870; EPR and
decoherence and, 1 071 0 ; evo lution to probability, global
induction
15763 ;
fro m
local
conditions, 636 8 ; Heisenberg's
zation of observables, 244 46 preSocratic philosophy, mutually exclusive relata and, 81 0 Principia
Mathematica
(Russell
and Whitehead), 9095, 1 172 1 , 130 Principle of Identity (PI), 303 1 ;
1 37n52; logically
category theory and, I 27; quan
related actual occasions, 1 68
tum actual occasions, 1 7073;
concept of, quantum
69;
mechanics
and
Boolean logic and, 475 1 , 359
relational realism and, 9295 Principle
of
NonContradiction
60; quantum theory and, x vi
(PNC), 2527, 3 1 ; Boolean log
xx ; relational realism and quan
ic and, 3239 ; causal relation
tum mechanics and, 8 695
and logical integration, 6870;
potential outcome states, quantum superposition and, 3339
compatibility condition for logi cal causality and, 6063, 1 5 1
potential simultaneous observabil
56; EPR and decoherence, 1 051 0 ; EPR and quantum nonlocal
ity, 35960 predication: EPR and decoherence
ity, 7380; exclusive disjunc
and, 1 051 0; logical types theo
tion and, 4 1 , 5 1 , 135n l l ; inter
ry and, 1 1 6 1 9 ; in quantum me
nal
chanics, 1 0334; self reference
mechanics and, 5758 ; objec
in
tive superposition of states and,
quantum
1 1 01 5 ;
mechanics
Theory
of
and,
Logical
Types and, 1 1 932 presheaf
sets:
display
relations
40 43 ;
and
quantum
potentialityprobability
evolution and, 1 5963; quantum bundles,
actual occasions, 1 7073 ; quan
completion and functionaliza
tum mechanics
tion, 2525 3 ; functor of Boole
logic and, 435 1 , 1 39; relational
an reference frames, 27073;
realism and, 8 895, 1 0 l n65
globaltolocal
and Boolean
compatibility,
Principle of the Excluded · Middle
gluing operations, 24648 ; lo
(PEM), 3 1 ; EPR and decoher
calization topology and, 234
ence, 1 05 1 0; EPR and quan
413
INDEX domain,
36064;
tum nonlocality, 7380; exclu
quantum
sive disjunction and, 4 1, 5 1,
quantum theory and, 35660;
135n l l ; internal relations and
relational local ization, 36472
quantum mechanics and, 575 8 ; internal relations in quantum
product states, composite system entanglement, 29094
mechanics and, 14247 ; objec
projection operator: entanglement,
tive superposition of states and,
EPR correlations, 3 1 0 1 3 ; lo
4043 ;
calization theories, 36264
potentialityprobability
evolution and, 15963; quantum
propertyindicating facts, quantum
actual occasions, 17073; quan
event classification, 3 1 317
tum mechanics
and
Boolean
logic and, 435 1 ; quantum su perposition and, 3 839; rela realism
tional
and,
8 895,
Protagoras, 22, 303 1 pullback:
category
theory,
227;
covering sieves as representable functors,
25859;
localization
topology and, 23 840; quantum
1 0 l n65 probability: compatibility condition
event classification, 3 1 7; quan
for logical causality and, 6063;
tum events interpretation, 305
potentiality evolution to, 1 57
7; truth valuation, Boolean lo
63;
quantum
mechanics
and
calization system, 3 1 823
455 1 ;
pure state: composite system en
quantum theory and, xvixx,
tanglement, 28 894; entangle
3739; quantum topology, 264
ment, EPR correlations, 30813
Boolean
logic
and,
Pythagorean theorem, 2 1 , 48
65 Process and Reality (Whitehead),
2327, 8795; extensive con
quantum gravity, differential exten
nection theory in, 1 8792; lo
sive connection and, 37684
calization schemes and, 2 1 7 1 9 ;
quantum
logical
event
algebra:
mereotopology in, 1 7984; phi
Boolean germs and, 26 165;
losophy of mathematics and,
classification, 3 1 317; internal
1 1 92 1 , I 23, 1 25, 13 0
localtoglobal ontological for mation,
26870;
cepts, 35356� differential ex
events
interpretation,
tensive
connection,
quantum
truth valuation, Boolean locali
gravity
applications,
37684;
zation system, 3 1 823
process
metaphysics:
basic con
germs and extensive connec tion,
37276;
localization
in
quantum 3037;
quantum mechanics: Boolean logic, 435 1 ;
category
theory
and,
INDEX
414 1 2732; compatibility condition
quantum
nonlocality,
xiiixx;
for logical causality and, 1 48
decoherence and, 1 091 0 ; EPR
56; cosmology and, l 0  1 2, 15
correlations and, 7 1 80, 1 09l 0
20; decoherence and, 6870;
quantum
superposition,
3239;
3037;
composite system entanglement,
historic interpretation, xvxviii;
2 8894; internal relations and,
internal
5258 ,
1 4547; objective superposition
1 4047; interpretive problems
of states and, 4043 ; potentiali
in, xiii�xx; localization theories
typrobability
and, 2 1 3 1 6; local topological
1 60
events
interpretation, relations
in,
evolution
and,
region and events in, 20 19; causality
logical
in,
5 863,
1 3 972� logicalextensive rela
rationalist
philosophy,
mutually
exclusive relata and, 1 2
tion integration in, 1 7996; log
real numbers: localization theories,
ically related actual occasions,
2 1 3 1 6 ; relational localization,
1 6869; logical types theory
36672
and, 1 1 6  1 9 ; objective indeter minacy and, 3943; objective local contextuality and, 3 943 ; objective states,
superposition 40 43 ;
of
potentiality
recoherence, Boolean localization, 3 3645 reduction:
fallacy
of misplaced
concreteness and, 1 3 2 1 ; mutu ally exclusive relata and, 1 2
probability evolution and, 1 5 8 
reductivedeductive epistemology,
63; potentiality to probability
fallacy of misplaced concrete
evolution in, 1 5 763; predica
ness and, 1 62 1
tion in, 1 0334; process meta physics and, 35356; reference frames, 33032; relational lo calization,
36472;
reference
contexts,
localization
topology and, 23940 reference frames: Boolean functors,
relational
270�73 ; classical to quantum
1 6368,
transition, 33032; gluing iso
34552; self reference problem
morphism, 2 8 1 84; sheaf local
and,
ization, 27779
realism and, 1 1 0 1 5 ;
Boolean
logic
8695,
separation from,
of
3239;
relata, relations as, 1 1 932; logical
sheaf theory and, 34552, 356
ly related actual occasions, 1 68
60� substance and logic in, 29
69;
95; topological vs. metrical rela
1 7 984
tions in, 8085
quantum mechanics
and,
415
INDEX
relational decomposition, quantum event cl assification, 3 1 3 1 7
losophy
relational localization, 3 6472 relational
realism:
Russell's paradox, 1 8 , I I 6 19; phi of mathematics
and,
1 3032
categorysheaf
theory and, 1 99209; category
Schrodinger's Cat: EPR and deco
theory and, 22832; dipolar du
herence, 1 06 1 0 ; objective su
and
perposition of states and, 41 43 ;
7 1 80,
quantum mechanics and Boole
in
an logic and, 435 1 ; quantum
quantum mechanics and, 1 39
superposition and, 3339; quan
72; mereotopology and,
tum theory and, xvixx
ality
and,
quantum 99n46;
2627;
EPR
nonlocal ity, logical
causality
1 94
96; partial congruence and ad
scientific method: bipolar dualism
junction, 32830; potential ity
and, 1 0 1 2 ; Boolean logic sepa
probability evolution and, 157
ration from, 3239, 1 4647; fal
63 ;
lacy of misplaced concreteness
quantum
1 6368;
dipolar
quantum
events,
mechanics
and spacetime and, 8485, 35960; quantum theory and, x vi xx,
xxn3 ;
sheaf theory
and,
34552; speculative philosophy and, 327; Whitehead's cosmol
and, 1 32 1 seed of extension, set theory/sheaf theory semantics, 25657 selfdeterm ination, of actual occa sions, 1 6368 self reference: quantum mechanics and, 1 1 0 1 5 ; relational realism
ogy and, 8 695 relativistically restricted data, 1 1 9
and, 2089 semantic
20, 1 3 132 relativity theory, 1 97n4; quantum
transition,
decoherence,
3 4045 set theory, 1 36n3 1 ; category theory
theory and, x ivxx
and, 1 3 1 32; localization theo
Rescher, Nicholas, 233 globalto
ries and, 2 1 3 1 6 ; relational lo
local compatibility, gluing op
cal ization, 36572; topological
erations, 24748
relations and, 25357
restriction
operations,
rotational invariance, entanglement,
sheaf theory:
EPR correlations, 309 1 3 Russell,
B ertrand,
1 8284;
Theory
Types, 1 1 932
1 8, of
sheaf theory. See
also
category
Boolean
germs
1 1 6,
and extensive connection, 372
Logical
76; classical to quantum transi
91,
tion, 3 3 2 ; decoherence, Boolean localization, 33745; differen
INDEX
416 tial extensive connection, 379
40; relational realism and, 202
84; display bundles, completion
9; in thermodynamics, 1 9 8n l 3 ;
and functionalization, 25253 ;
topological
entanglement, EPR correlations,
tions in, 8085
307 1 3 ;
functorial
entangle
spectral
vs.
metrical rela
decomposition:
Boolean
ment, 296303; globaltolocal
topological significance, 266
compatibility,
67; composite system entan
gluing
opera
tions, 2464 8 ; gluing axiom in, 6768 ;
internal
relations
in,
1 9 192; ·localization topology
glement, 28894 spectrum holes, relational localiza tion, 37072
and, 234 40, 36064; overlap
speculative philosophy: mathemat
ping structures, 1 505 1 ; partial
ics and, 1 2032; relational real
congruence
and
adjunction,
ism and, 327
32830; process metaphysics,
Spinoza, B aruch, 12, 5 9
35556; quantum events and,
spin particles: entanglement, EPR
1 9 920 8 ; quantum localization,
correlations, 307 1 3 ; EPR and
sheaf
quantum
of
Boolean
reference
nonlocality,
7 1 80,
frames, 27779; quantum me
9 8 n40, 99n4 1 ; internal relations
chanics and, 35660; quantum
and,
relational realism and, 34552;
events and, 2049; properties
relational localization, 3 6472;
of, 99n41
set theory semantics and, 253
1 4547;
split discrete
local
fibration,
quantum
24546;
57; sheaf of germs, contextuali
functor  of Boolean reference
ty, 2485 1 ; sheaf of germs, uni
frames, 27073
form localization of observa bles,
244 46;
topology
and,
singlet pure state, entanglement, EPR correlations, 308 1 3 classical
7, 33745 Stone space, 3057
spacetime continuum (spatiotem extension):
ment, 28794 Stone representation theorem, 305
1 82, 1 86
poral
state, composite system entangle
to
quantum transition, 3 3032; dif ferential extensive connection and, 37784; dipolar predica tion and, 1 1 920, 1 3 1 32; lo calization topology and, 234
structurepreservtng
mapptngs:
•
•
category theory, 222; process metaphysics, 35456 subjectsuperject concept, White head's actual occasion and, 209 subobject
functor:
measurement
events, Boolean germ classifica
INDEX
417
tion, 32326; partial congruence
as representable functors, 257
and adjunction, 330; quantum
59; decoherence analysis, 340
event classification, 3 1 4 1 7
45; differential extensive con
substance, relational realism and quantum mechanics and, 8695 subsystems: EPR correlations, 30713;
functorial
entanglement,
295303
nection, 37784; display bun dles, completion and functional 2525 3 ;
ization,
genetic
analysis, 3 3334; gluing sec tions and globaltolocal com
superluminal
energy
transfer,
99n48
patibility, 24648; internal lo ontological
caltoglobal
systemenvironment
relations:
formation, 26770; localization
compatibility condition for logi
theories and, 2 1 5 1 6, 23340,
cal causality and, 1 5 156; po
3 6064; local topological re
tentialityprobability
gion, 200209; process meta
evolution
and, 1 5 963
physics, events
temporal
antecedence, EPR and
· quantum nonlocality, 7380
35456;
quantum
interpretation,
3057;
quantum mechanics and, 1 8284; space localization, 243 44;
tensor product, 28794
spacetime in quantum mechan
terminal obj ect, category theory,
ics and, 8085 topos structures, set theory/sheaf
226 Theaetetus (Plato), 1 7 1 8
theory semantics and, 25457
Theory of Extension (Whitehead), 8995
total spin conservation, entangle ment, EPR correlations, 309 1 3
Theory of Logical Types. See logi cal types, theory of
trace function, 98n34 transcendental
Theory of Prehension (Whitehead),
philosophy,
com
plementarity and, 1 2 transformations, classical to quan
8995 topological relations: asymmetrical internal structure, 1 37n49, 1 5056; basic principles,
1 00n50;
Boolean
26667;
contexts,
tum transition, 3 3032 transitivity, localization topology and, 23840 translational
coding,
functorial
Boolean germs, 26184; catego
Booleanquanter internal rela
rysheaf theory and,
tion, 27577
1 2732;
contextuality, sheaf germs and
transmutation mechanism: concres
stalks, 2485 1 ; covering sieves
cence and, 16263 � functorial
INDEX
418 Booleanquantum internal rela tion, 27377; relational realism
Von Neumann universe (set theo ry), 1 36n3 1 Von Neuman's spectral theorem,
and, 35 1 52 Treatise on Universal Algebra, A
quantum observables, 26465
(Whitehead), 12023 , 1 26, 1 29 truth valuation: B o o lean localiza tion system, 3 1 823 ; localiza 36364; meas
tion theories,
urement events, Boolean germ classification,
32426;
partial
congruence and adj unction, 330
wavefunction mechanics, fallacy of misplaced
concreteness
and,
152 1 waveparticle complementarity, 67 "The Wave Function of the Uni verse" (Hawking and Hartle), 1 5
methodology:
Whitehead, Alfred North: category
functorial entanglement, 296
theory and, 22732; extensive
303; localization of observables,
connection theory of, 1 8590,
24546; variable set presheaves,
234 40, 332, 35052, 37276;
23233
fallacy of misplaced concrete
uniform
fibration
unit of relation, dipolar duality and, 2527 universality, category theory, 22732
ness and, 1 32 1 ; genetic analy sis concept of, 33334; internal localtoglobal ontological for mation,
26970;
localization
schemes and, 2 1 6 1 9 ; mereoto Valenza, Robert, 12627, 1 29
pology theory of, 1 7984; phi
variable references, category theo
losophy of mathematics and,
ry, 22022
1 1 934; process theory of, 1 99
vector sheaves, 3 8 184
209, 3 5 860; quantum actual
Von Neumann, John: bipolar dual
occasions of, 1 6368, 2029;
ism and, 5 ; internal relations
quantum theory and work of,
and quantum mechanics and,
xvixx; relational realism and
545 8 ; projection postulate of,
philosophy of, 8695 ; on specu
xviiixx; quantum superposition
lative philosophy, 3 ; Theory of
and, 3 73 9; self reference in
Logical Types, 1 1 920; topo
quantum mechanics and, 1 1 1 
logical localization and, 33334
15 Von Neumann chain, 1 6468
Yoneda Lemma, 23 132 Young, Thomas, 95n4
INDEX
Zafris , Elias,
64, 6768 , 8 185 ;
quantum theory and, x viiixx ZermeloFraenkel (ZFC) set theory,
1 36n3 1 Zurek, Woj ciech, 1 6063
419
ABOUT THE AUTHORS .
Michael Epperson did his doctoral work in philosophy of science and philoso
phy of religion at The University of Chicago, and earned his Ph.D. there in 2003. His dissertation, Quantum Mechanics and the Philosophy of Alfred North
Whitehead, was written under the direction of philosopher David Tracy and physicist Peter Hodgson, Head of the Nuclear Physics Theoretical Group at the University of Oxford. It was published the following year by Fordham Universi ty Press, and rereleased in paperback by Oxford University Press in 20 12. He is currently the founding director of the Center for Philosophy and the Natural Sciences in the College of Natural Sciences and Mathematics at Califor nia State University, Sacramento, where he is a Research Professor and Princi pal Investigator. Elias Zafiris holds an M.Sc. (Distinction) in Quantum Fields and Fundamental
Forces from Imperial College at the University of London, and a Ph.D. in theoretical physics from Imperial College. He has published numerous papers on categorytheoretic methods in quantum physics and complex systems theories, topological localization and modern differential geometry in quantum field theo ry and . quantum gravity, generalized spacetime quantum theory, decoherence, and many other topics in the foundations of physics. He is a research professor in theoretical and mathematical physics at the In stitute of Mathematics at the University of Athens, and is currently a visiting professor in the Department of Logic, Institute of Philosophy, Eotvos Lorand University in Budapest. He is also a senior research fellow and Principal Inves tigator at the Center for Philosophy and the Natural Sciences in the College of Natural Sciences and Mathematics at California State University, Sacramento.