New Scientist July 20 2019

Citation preview

SIBLING RIVALRY

How birth order shapes your health and personality

GUILT-FREE FLIGHTS

Does carbon offsetting work?

SUPER FLY

Rubbish-eating bug that could save the world WEEKLY 20 July 2019

THE GREAT METAMORPHOSIS A mind-blowing new theory on the fate of the universe

No3239 £4.95 CAN$7.99

2 9

PLUS AN AI TRIUMPHS AT POKER / TERRAFORMING MARS / THE GENETICS OF ANOREXIA / MEGA WIND FARMS

9 770262 407312

#Space Twitter

Smart technology does more than take selfies. From helping pilots avoid turbulence to making cars more intuitive to reinventing retail, IBM is working behind the scenes to change the way the world works. Find out how at ibm.com/smart/uk

This week’s issue

On the cover

Coming next week

42 Sibling rivalry How birth order shapes your health and personality 20 Guilt-free flights Does carbon offsetting work?

34 The great metamorphosis A mind-blowing new theory on the fate of the universe

38 Super fly Rubbish-eating bug that could save the world Outsmart yourself A scientific guide to gaming your mind and achieving your goals 16 An AI triumphs at poker 14 Terraforming Mars 8 The genetics of anorexia 10 Mega wind farms Vol 243 No 3239 Cover image: Karan Singh

News

Features

9 Cosmic mystery Our understanding of the universe is fatally flawed

34 The great metamorphosis Our universe was supposed to last forever. Now a cosmic transformation looms

News

12 Genetic healthcare Are we really ready to know what our genes say about our health?

38 Super fly Meet the edible insect that could solve our food waste crisis

16 AI poker champion Artificial intelligence masters Texas Hold ’Em at last

42 Sibling rivalry How much does birth order really shape our lives?

Views

The back pages PAUL LANGROCK/ZENIT/GREENPEACE

23 Comment Don’t use fitness trackers to self-screen for heart conditions, argues Margaret McCartney 24 The columnist Graham Lawton on the first ever National Park City

51 Maker Use electronics to find out if your plant is happy 52 Puzzles The crossword, a snail-paced puzzle and a quick quiz

10 Artificial islands The plan to build mega wind farms in the North Sea 26 Letters Understanding the ninth wonder of the brain 28 Culture Our pick of the best summer reading and listening 30 Aperture Colourful delights of trees

34 Features

“The universe may be destined to evolve into a state we don’t even have the language to describe”

53 Feedback Grave consequences and quantum queues 54 Almost the last word Galactic distance and menthol cold 56 Me and my telescope Vivian Li is building a mini bowel to fight cancer

20 July 2019 | New Scientist | 3

The Human Body is

Remarkable. It inspires our mission to discover, develop and deliver innovative medicines that help patients prevail over serious diseases. www.bms.com/gb

Jobcode: NOUK1900519-02 Date of Prep: June 2019

The leader

Resetting offsetting

AVIATION-IMAGES.COM/UNIVERSAL IMAGES GROUP VIA GETTY

Properly done, carbon offsetting really can benefit the climate GREENWASH? The question may loom large as your hand hovers over the “offset emissions” button on an airline website. Can you really negate the environmental damage of a flight or other polluting activity by paying to plant an extra tree here, or investing in a solar panel there? Or is carbon offsetting just a fig leaf to disguise our embarrassingly tiny efforts to combat climate change? Yes and no. Carbon offsetting is no substitute for effective action to reduce greenhouse gas emissions, but well-designed schemes can be a stopgap while we seek ways to avoid emitting in the first place (page 20). Flying is particularly tricky because, as yet, there are few credible alternatives to fossil-fuelled flight. Let’s be clear. Jetting across the world is a privilege, not a right, and the best way to limit its

Tackling greenhouse gas emissions from flights is tricky

impact is to do it less. There can be no excuse any more that the importance of what we do somehow trumps a shared duty to take action. Governments, companies, NGOs, scientists and everyone else must at all levels embrace technology and actively work to reduce globetrotting face-to-face meetings. No one wants to ban flying altogether, but there are measures we can all take. Choose airlines with newer, more efficient aircraft. Cut out short-haul

flights: most aircraft emissions are associated with take-off and landing, and ground-based alternatives are more readily available for those distances. On long-haul ones, fly direct where possible. Shun business class, where emissions per passenger are substantially higher. For what’s left, there is offsetting – as a supplement to, not a substitute for, reducing emissions. However, the current plethora of often conflicting offsetting standards is doing the sector no favours. There needs to be more transparency and third-party monitoring of what counts as credible offsetting. Airlines, travel companies and others promoting offsetting schemes must also do due diligence on what they are offering. That way, we can all press the right buttons to help make a difference. ❚

PUBLISHING & COMMERCIAL

MANAGEMENT

EDITORIAL

Display advertising Tel +44 (0)20 7611 1291 Email [email protected] Commercial director Chris Martin Display sales manager Justin Viljoen Lynne Garcia, Henry Vowden, (ANZ) Richard Holliman Recruitment advertising Tel +44 (0)20 7611 1204 Email [email protected] Recruitment sales manager Mike Black Nicola Cubeddu, Viren Vadgama, (US) Jeanne Shapiro New Scientist Live Tel +44 (0)20 7611 1206 Email [email protected] Events director Adrian Newton Creative director Valerie Jamieson Sales director Jacqui McCarron Exhibition sales manager Charles Mostyn Event manager Henry Gomm Marketing Head of campaign marketing James Nicholson Poppy Lepora, Chloe Thompson Head of customer experience Emma Robinson Email/CRM Manager Rachna Sheth Head of data analytics Tom Tiner Web development Maria Moreno Garrido, Tom McQuillan, Amardeep Sian

Chief executive Nina Wright Finance director Jenni Prince Chief technology officer Chris Corderoy Marketing director Jo Adams Human resources Shirley Spencer HR coordinator Serena Robinson Facilities manager Ricci Welch Executive assistant Lorraine Lodge Receptionist Alice Catling

Editor Emily Wilson Executive editor Richard Webb Creative director Craig Mackie News News editor Penny Sarchet Editors Jacob Aron, Timothy Revell Reporters (UK) Jessica Hamzelou, Michael Le Page, Donna Lu, Adam Vaughan, Clare Wilson (US) Leah Crane, Chelsea Whyte (Aus) Alice Klein, Ruby Prosser Scully Digital Digital editor Conrad Quilty-Harper Web team Lilian Anekwe, Anne Marie Conlon, David Stock, Sam Wong Features Head of features Catherine de Lange (parental leave) and Rowan Hooper Acting head of features Tiffany O’Callaghan Editors Gilead Amit, Julia Brown, Kate Douglas, Alison George, Joshua Howgego Feature writers Daniel Cossins, Graham Lawton Culture and Community Editors Liz Else, Mike Holderness, Simon Ings Subeditors Chief subeditor Eleanor Parsons Bethan Ackerley, Tom Campbell, Chris Simms, Jon White Design Art editor Kathryn Brazier Joe Hetzel, Dave Johnston, Ryan Wills Picture desk Chief picture editor Adam Goff Kirstin Kidd Production Production manager Alan Blagrove Robin Burton, Melanie Green

© 2019 New Scientist Ltd, England. New Scientist is published weekly by New Scientist Ltd. ISSN 0262 4079. New Scientist (Online) ISSN 2059 5387. Registered at the Post Office as a newspaper and printed in England by Precision Colour Printing Ltd

Non-exec chair Bernard Gray Senior non-exec director Louise Rogers

CONTACT US newscientist.com/contact General & media enquiries Tel+44 (0)20 7611 1202 UK Tel+44 (0)20 7611 1200 25 Bedford Street, London WC2E 9ES Australia PO Box 2315, Strawberry Hills, NSW 2012 US Tel +1 617 283 3213 210 Broadway #201, Cambridge, MA 02139 UK Newsstand Marketforce UK Ltd Tel +44 (0)20 3787 9001 Syndication Tribune Content Agency Tel +44 (0)20 7588 7588 Email [email protected] Subscriptions newscientist.com/subscribe Tel +44 (0)330 333 9470 Email [email protected] Post New Scientist, Rockwood House, Perrymount Road, Haywards Heath, West Sussex RH16 3DH

20 July 2019 | New Scientist | 5

YEMEN EMERGENCY

No home, no food and no medical care. Who will help them? There is no escape for families in Yemen who are fleeing their homes because of war. Thousands of children have nothing – no home, no clean water, no food, and no hospital to go to when they are ill or injured. Many have no choice but to live on the streets and beg for food. Will you help them?

£75

© UNHCR/Mohammed Hamoud

The people of Yemen are in urgent need. Please help them today. COULD HELP DISPLACED FAMILIES BUY FOOD AND RECEIVE LIFE-SAVING MEDICAL TREATMENT, CLEAN WATER, SAFE SHELTER AND OTHER ESSENTIAL ITEMS

Give online at: unhcr.org/helpyemen or call us on 0800 029 3883



Or post urgently to: Freepost UNHCR. You do not need a stamp. Please accept my gift of:

Please debit my: Card no. Valid from / Signature

£150 Visa

£225 MasterCard

Other £ First name

Maestro Maestro only

Expiry date /

Last name Address

Issue number Maestro only Date

/

/

I enclose a cheque or postal order made payable to UNHCR Please tell us if you are happy to hear about U NHCR’s work:

By email By phone We will use your details to process your donation and to keep you up to date with our work, fundraising activities and other events. You can read more about how we use your data in our Privacy Policy www.unhcr.org/uk/privacy-policy. You can opt out of any communications at any time by emailing [email protected] or by calling 0800 029 3883.

Postcode Email Phone Your donation will support UNHCR’s emergency work in Yemen and where refugees and internally displaced people are in need.

NSCPAYE19A

£75

News Anorexia genes The condition may have a metabolic component p8

Fast radio bursts Space explosions can’t explain the mystery p10

Terraforming Mars A silica blanket could let plants thrive on the Red Planet p14

Online videos Streaming is to blame for nearly 1 per cent of global emissions p15

Healthy living Lifestyle choices may stave off dementia in those at risk p16

Infectious disease

Virus outbreak reaches big city

ISRO HANDOUT PHOTOGRAPHS HANDOUT/EPA-EFE/SHUTTERSTOCK

A CASE of Ebola has been confirmed in Goma, the first in a major city since the outbreak that has killed 1700 people began in the Democratic Republic of Congo (DRC) last year. That is despite efforts to contain the virus, including giving around 160,000 people a vaccine made by Merck that seems to be 97 per cent effective. But the Wellcome Trust, a health charity, warned supplies of this could run out. It urged the use of a second vaccine, made by Johnson & Johnson. DRC health minister Oly Ilunga responded by saying there is no need for another vaccine. ❚ Michael Le Page

India’s moonshot on hold The nation wants to land a rover near the lunar south pole but the mission hit a snag minutes before lift-off, says Leah Crane INDIA’S attempt to land on the moon is facing a setback. The launch of its Chandrayaan 2 mission was scheduled for 14 July, but was halted less than an hour before lift-off because “a technical snag” was observed in the launch vehicle system, said the Indian Space Research Organisation. The mission is the successor to Chandrayaan 1, which blasted off in 2008 and consisted of a lunar orbiter and an impactor that slammed into the surface of the moon. The resulting collision released a cloud of debris, including water vapour that confirmed the presence of this substance on the moon. Chandrayaan 2 will also have an orbiter to relay data back to Earth,

as well as a lander called Vikram and a small rover called Pragyan. Between these three craft, the mission will have a total of 14 scientific instruments, including cameras and spectrometers for studying the moon’s surface, radar for probing deeper and a seismometer that can detect moonquakes. The lander should touch down near the lunar south pole in September. Pragyan’s six wheels will allow it to trundle at about 1 centimetre per second across the moon’s surface and study the chemical make-up of dust there. Vikram and Pragyan are designed to last for one lunar day – about 14 Earth days – before the intense cold of the lunar night means they

won’t be able to work anymore. In recent years, orbiters have spotted water ice in craters at the south pole, which remain cool because they are perpetually in shadow. That makes this part of the moon particularly interesting for human exploration, and many space programmes are targeting it for further study. If all goes well after the eventual launch of Chandrayaan 2, it will make India the first nation to land near the south pole and just the fourth to land softly on the moon, following controlled touchdowns by the US, USSR and China. As New Scientist went to press, a new launch date for the Chandrayaan 2 mission hadn’t yet been announced. ❚

Neuroscience

Women as aroused by sexual images WOMEN’S brains react to sexual images just as much as men’s, challenging the belief that men are more turned on by visual stimuli. There is wide variation in behaviour among both sexes, but men are assumed to be more interested in sexual images, an idea seemingly confirmed by brain scans. But such studies have been criticised for drawing conclusions from small differences that could have arisen by chance. Now, a review of 61 brain scanning studies found no difference between men and women’s response to sexual images (PNAS, doi.org/c8cf). ❚ Clare Wilson 20 July 2019 | New Scientist | 7

News Genetics

Anorexia may be a metabolic disorder Jessica Hamzelou

“There’s no medication for anorexia – probably because we don’t understand its causes” because we don’t understand the underlying causes.” Previous research has found that genetic factors, as well as environmental ones, can increase a person’s risk of anorexia. To investigate, Bulik and her colleagues compared the genomes of just under 17,000 people with anorexia with those of 55,500 people who didn’t have the condition. They pinpointed eight locations across the genome that seem to

play a role in anorexia. But this is likely to represent only a tiny fraction of all the genetic factors involved in the condition, says Bulik. “It’s a complex trait, so we expect lots of genes to each have a small to moderate effect,” she says. The researchers compared their results with similar genetic studies of other traits, ranging from other psychiatric conditions to personality. They found that anorexia seems to be correlated with obsessive compulsive disorder and depression, suggesting that these all share genetic factors. This makes sense, says Bulik, as people with these conditions often show similar symptoms. The team also found a genetic correlation between anorexia and high physical activity. “We know that people with anorexia have a really hard time sitting still,” says Bulik. Doctors have tended to think this is a psychological symptom – an effort to lose weight. But this study suggests there is some genetic drive to move, says Bulik. The team also uncovered correlations with factors such

Genes linked to anorexia may also be involved in depression and body fat

NICOLAS/GETTY

A GENETIC study of more than 72,000 people suggests that anorexia nervosa isn’t just a psychiatric condition – it is a metabolic one, too. Anorexia affects between 0.9 and 4 per cent of women and 0.3 per cent of men, but is still poorly understood. “Anorexia has the highest mortality rate of any psychiatric disorder,” says Cynthia Bulik at the University of North Carolina at Chapel Hill. “There’s no medication, and that’s probably

as body fat, body mass index and resistance to the blood-sugar regulating hormone insulin (Nature Genetics, doi.org/c8cg). This seems to suggest anorexia nervosa can have a metabolic component, says Gerome Breen at King’s College London, who worked with Bulik on the study. “It’s a very exciting advance in our understanding of the genetics of the disorder,” says Dolores Malaspina at the Icahn School of Medicine at Mount Sinai in New

York. “It may suggest other ways beyond psychological ones to help people gain weight.” But Malaspina cautions that the latest genetic clues are only a small part of the puzzle of anorexia. Given the complexity of the condition, there are likely to be varying subtypes – some people may have more of a psychiatric condition while others might have more of a metabolic condition, says Bulik. She hopes that genetic tests will one day diagnose subtypes and help tailor treatment. Bulik also hopes that the findings will help to reduce the stigma and misunderstanding of anorexia. Family doctors can still blame the parents of someone with the condition, or accuse girls with anorexia of being vain, she says. And even today, boys and men are told they can’t have anorexia, because it is a “girl’s disorder”, she says. “I hope this changes the way people think about this illness,” says Bulik. ❚

Ecology

ELEPHANTS do a lot of damage to plants as they stomp around the jungle, but, counterintuitively, this activity increases the biomass of the forest, letting it store more carbon. Fabio Berzaghi at the Laboratory of Climate and Environmental Sciences in Gif-sur-Yvette, France, and his colleagues wondered if elephants’ destructive habits might 8 | New Scientist | 20 July 2019

allow surviving trees to grow larger by eliminating their competition. They built a mathematical model of plant diversity and simulated the impact of elephants by increasing the mortality of smaller plants. The model showed that elephants reduce the density of stems in the forest, but increase the average tree diameter and the total biomass. Overall, they favour slow-growing trees that live longer and store more carbon in their trunks (Nature Geoscience, doi.org/c8cd).

The model results fit with data from sites in the Congo basin in central Africa where elephants live and comparable areas that are undisturbed by the animals. These effects may also explain Elephants are destructive in a good way

GETTY

Destructive elephants help forests store carbon

differences between African and Amazonian rainforest. The Amazon, which has no large herbivores, has more trees per hectare, but they tend to be smaller and hold less biomass in total. Elephant populations have crashed since the early 19th century. The study estimates that, in due course, the loss will reduce the biomass of African forests by about 3 gigatonnes of carbon. That is equivalent to 14 years’ worth of carbon emissions from the UK. ❚ Sam Wong

Quantum and gravity newscientistlive.com/ big-physics Cosmology

A mystery of the cosmos Our understanding of the universe is fatally flawed and new measurements only seem to make it worse, finds Leah Crane

Gravitational lensing bends and amplifies the light from a quasar

The distance ladder method has consistently resulted in an expansion rate more than 9 per cent higher than the CMB method, causing much consternation among astronomers. “If you have two measurements that don’t agree, there is always a chance that one of them or both of them are wrong,” says Simon Birrer at the University of California, Los Angeles. Now, Birrer and his colleagues have used a third method, based on gravitational lensing, a phenomenon where light from a distant object is bent by the gravity of a closer galaxy on its way to our telescopes. By analysing how this happens, it is possible to measure distances and, when combined with other measurements, the Hubble constant too. The researchers went through this process for three quasars, which are some of the brightest

EUROPEAN SPACE AGENCY, NASA, KEREN SHARON (TEL-AVIV UNIVERSITY) AND ERAN OFEK (CALTECH)

SOMETHING is badly wrong with the expansion of the universe. Nearby galaxies seem to be moving away from one another too fast, we don’t know why and every new set of data just seems to make the problem worse. We have two basic ways to measure the expansion of the universe, which is described by a number called the Hubble constant. The two methods have always returned clashing results, and many researchers hoped that one of them was simply wrong. But two new measurements seem to have made matters worse. One of them solidifies the disagreement between the measurements, making it seem like both could be correct. The other muddies the water even further by disagreeing with all the measurements so far. The results could mean we need a major reworking of our understanding of the universe. One of the traditional ways to measure the Hubble constant is with the cosmic microwave background (CMB), the remains of the first light to stream across the cosmos after the big bang. Patterns in that light show how fast the universe was expanding then, and researchers use models of how it has evolved since to tell us how fast it ought to be expanding now. The other main way is using what is known as the “distance ladder”, which involves measuring the distance to stars called Cepheid variables, linking those distances to nearby supernovae and then using those supernovae to determine how fast relatively nearby galaxies are moving away from us.

objects in the universe and reside at the centres of some galaxies. Their measurements matched the results from the distance ladder method. With this independent confirmation, they say it is increasingly likely that both the conflicting measurements of the universe’s expansion are correct. This is because of the boost the

“The results could mean we need a major reworking of our understanding of the universe” new result gives to the distance ladder method, which is based on more complex and less established physics than the CMB measurement, making it easier for cosmologists to disbelieve. The tension has now reached a confidence level of 5 sigma, meaning that if the seemingly incompatible measurements

aren’t both correct then the odds are just one in 3.5 million that the results could be produced by random chance (arxiv.org/ abs/1907.02533). In some areas of physics, this confidence level constitutes a true “discovery” instead of just an intriguing piece of data. But it may not all be so simple. Within a few days of the lensing measurement, Wendy Freedman at the University of Chicago and her team released yet another independent measurement of the Hubble constant. They used a different group of stars, called the tip of the red giant branch, to build a new distance ladder. What they found was surprising: a value of the Hubble constant right between the CMB measurement and the original distance ladder (arxiv.org/ abs/1907.05922). This is more evidence that we really don’t understand what the value of the Hubble constant is, and that we need much more precise studies before we can claim that there must be some new type of exotic physics, says Freedman. “The mystery heightens,” she says. There is no current theory that can explain all the measurements so far. So either we need to reconsider the measurements or reconsider our understanding of the physics. “The Hubble constant is the biggest problem in cosmology that we have access to right now,” says Daniel Scolnic at Duke University in North Carolina. “The hope is that this crack in our understanding is going to lead us to some even bigger cracks like dark energy and dark matter. We just have to chase the crack.” ❚

To explain the universe, think weirder, page 34 20 July 2019 | New Scientist | 9

News Renewable energy

Mega wind farms in the North Sea Adam Vaughan

PAUL D HUNTER PHOTOGRAPHY/ALAMY

more than 12 million UK homes. By comparison, the biggest offshore wind farm being built in the North Sea today will have a capacity of just over 1 GW. The project would only benefit from economies of scale if the hubs were 10 to 15 GW, while making them any bigger would see longer construction times and more financial risk, says Muller. The wind farms could utilise turbines much bigger than the largest in UK waters today. Currently, the biggest being

Wind hub islands A consortium wants to build a series of artificial islands in the North Sea, surrounded by wind farms, which would send electricity supplies back to the UK and continental Europe. Below is one proposed configuration Island hub Electricity connection point Electricity connection NORWAY

DENMARK UK

NETHERLANDS

GERMANY

SOURCE: NORTH SEA WIND POWER HUB

RADICAL plans for artificial islands connecting a series of vast wind farms in the North Sea have inched closer to reality after an initial assessment concluded that the idea is technically feasible. The scheme’s backers say the project is needed because offshore wind farms are being built in Europe too slowly to deliver the goals of the Paris climate agreement, and space is running short near coastlines to cheaply install turbines. The North Sea Wind Power Hub, backed by a consortium including Dutch energy network firm TenneT, previously envisaged the scheme as one big sand island acting as a hub for wind farms radiating off it. But Michiel Muller of TenneT says the consortium’s research suggests a series of smaller islands would be better. “We believe that the concept we present is both technically feasible and economically feasible,” says Muller. The first of up to eight island hubs could be built by the early 2030s. The islands would contain equipment for transmitting power efficiently to shore. The aim is for each island to connect a series of wind farms with a collective capacity of up to 15 gigawatts, enough to power

installed are around 8 megawatts and taller than London’s 180-metre-high “Gherkin” skyscraper, but 12 MW ones have already been unveiled by turbine-makers and 15 MW ones are expected by 2030. The island hubs could be linked to Germany, the Netherlands and the UK, as well as Norway and Denmark (see “Wind hub islands”, left). However, as the first three of these countries have the furthest to go in decarbonising their energy supplies, they would probably be the initial focus, the consortium says. At a later stage, electricity from the hubs could be used to produce hydrogen – seen as crucial for decarbonising sectors such as industry – onshore, and then offshore too, using desalinisation. As well as sand, each island could be a steel structure or a gravitybased platform, like those often

Space is running out for cheap coastal wind farms in the North Sea

they occur, and compared that rate to the rates of cataclysmic events in our region of the universe. “The rate of FRBs appears to be higher than the rate of anything we can really think of that can make them,” says Ravi. That means that a single type of explosion or collision cannot account for all the FRBs we have seen even if there aren’t many of them (Nature Astronomy, doi.org/c8cj).

“We have suspected and have some evidence that there are multiple classes of FRBs, and what fraction belong to each class is unknown,” says Victoria Kaspi at McGill University in Montreal. Because none of our theoretical models thus far quite fits, she says it is also possible the FRBs are formed by events we have never seen or considered before. ❚ Leah Crane

used by oil rigs. Sand is the cheapest in most scenarios, says Muller, but it would take up to eight years to construct an island using it. Several possible locations for the island hubs were examined in the region of Dogger Bank, a submerged sandbank that is a relic of Doggerland, thought to have once connected the UK to continental Europe. The scheme’s success will hinge on whether it gets enough support from governments, says Kees van der Leun at the Dutch office of global consultancy firm Navigant, which contributed to the research. While the hubs might seem far off, there is an urgency to begin, he says. “For this kind of major infrastructure, lead times are long, and 2030 is around the corner.” ❚

Astronomy

Space explosions are too rare to explain fast radio bursts BRIGHT and weird phenomena in space often come from explosions or collisions. But this is unlikely to be the case for fast radio bursts (FRBs), one of the most mysterious space signals we have seen. FRBs are milliseconds-long bursts 10 | New Scientist | 20 July 2019

of powerful radio waves that come from the depths of space. They have been attributed to many different sources, from merging neutron stars to alien spaceships. So far, however, no explanations have proved completely satisfactory. Now, Vikram Ravi at the California Institute of Technology has used a few of the FRBs we have seen relatively close to Earth to calculate a lower limit on how often

Talks spotlight The immune therapy revolution Immunologist Daniel Davis explores the future of immune therapy. Find out how harnessing natural defences to create immune therapies will help XVĆJKWFDQFHUGLDEHWHVDUWKULWLVDQG many age-related diseases.

AI in ophthalmology Find out why Pearse KennEHOLHYHV WKDWRSKWKDOPRORJ\FRXOGEHWKHĆUVW EUDQFKRIPHGLFLQHWREHUHLQYHQWHG through the application of AI.

The power and beauty of mini organs Join Crick Institute Group Leader Vivian Li as she explains how miniRUJDQVRURUJDQRLGVKDYHWKHSRZHU WRUHYROXWLRQLVHRXUXQGHUVWDQGLQJ RIVWHPFHOOELRORJ\DQGSDYHWKHZD\ for personalised medicine.

The operating theatre of the future

Everyone knows someone living with cancer, heart disease, dementia, diabetes or another devastating condition. The good news is that research is making huge progress. What’s more new technologies such as ÆŐŞċƏâċÆġċĨŞìġġċĂìĨâìʭħìèċâÆġċħÆĂċĨĂʭʒ&ōŐċĨŞċĨĂÆĨè genetics are coming together to diagnose illnesses faster and provide personalised treatments.

Sign up to our newsletter get ʐʏ̍Įƌ Standard and All-Access tickets*

Buy tickets at NewScientistLive.com

*terms and conditions apply

SPONSORS AND PARTNERS

0$'9(57,6(6+877(5672&.

Healthcare of the future

Showcasing some of the groundEUHDNLQJZRUNE\.LQJV&ROOHJH London’s school of Biomedical (QJLQHHULQJDQG,PDJH6FLHQFHV take a look at the technologies that will FKDQJHWKHIXWXUHRIVXUJHU\IRUHYHU VXFKDVURERWLFVLPDJHDFTXLVLWLRQ 'SULQWLQJDQGDUWLĆFLDOLQWHOOLJHQFHLQ our Operating Theatre of the Future.

News

Future of healthcare newscientistlive.com/ future-health

Genetics

DNA testing on the NHS Offering genetic tests for predicting risk of common diseases to everyone could have negative effects on health, reports Adam Vaughan

UK health secretary Matt Hancock has championed genetic testing 12 | New Scientist | 20 July 2019

echoed those fears in its submission to the committee. “Knowledge of an increased risk for an untreatable disease, where there are no changes of lifestyle that may be beneficial, may cause a consumer only stress and anxiety,” it said. “In this case, the knowledge of this risk may therefore not be able to be considered a benefit to the consumer’s overall health.” For these reasons, it is important that genetic testing also involves a psychological assessment, says Saskia Sanderson at University College London. “Many of the potential harms of genomic testing are psychosocial or behavioural in nature.” These include anxiety or stress in response to high-risk results, or false reassurance in response to low-risk ones. “The same is true of the potential benefits too,” she says. Hancock revealed in March STEVE BACK/SHUTTERSTOCK

THE National Health Service (NHS) in England is set to offer genetic testing to help determine people’s risk of developing common diseases such as cancer and Alzheimer’s. However, some influential groups have warned that the move could have negative effects, including causing anxiety when people receive the results. UK health secretary Matt Hancock said the DNA tests would be available through the NHS, but it would be a paid-for service. Those taking the tests would have to agree to share their genetic data in an anonymised way with researchers, in the hope that a nationwide database could be used to benefit everyone. The Department of Health is expected to publish a green paper this week outlining the plans. Direct-to-consumer DNA testing companies such as 23andme have expanded their services over recent years to offer risk scores for conditions such as type 2 diabetes as well as providing people with data for family trees. In March, members of parliament on the UK Science and Technology Select Committee launched an inquiry on the benefits and risks of genetic testing for individuals and the NHS. In written evidence to the committee, the UK Research and Innovation (UKRI) funding body said that while tests offer potential health benefits, the results can also cause people to overestimate their risk of developing a disease. “This may in turn have negative impacts on the emotional wellbeing of that individual and their family,” it said. Stress and anxiety from results may even have a net negative health impact, it said. The UK Biochemical Society

that genetic testing by a private firm suggested he was at higher risk than most men of prostate cancer and he would be visiting his doctor to discuss the finding. However, the UKRI said genetic tests can’t accurately predict risk of prostate cancer yet, as they look at genetic variants “that are only

“Many of the potential harms of genomic testing are psychosocial, such as anxiety and stress” weakly associated with the disease or are of unclear significance.” Critics have also suggested that Hancock risks overburdening the NHS by encouraging others with DNA results to see their doctor unnecessarily. It isn’t yet clear how many people are going to their doctors for advice after receiving genetic test results. But Nicki Taverner

of the Association of Genetic Nurses and Counsellors says: “We have personal experience of patients who have received ‘worrying’ test results, who were not able to obtain the appropriate information or support direct from the company, who then ask for an NHS referral to genetics services to pick up the pieces.” A way to avoid misinterpretation is for results to be presented and explained by a genetic counsellor. “For example, if an individual is informed that their risk of cancer has doubled, without adequate counselling, this is likely to have adverse effects on their mental health,” wrote the Biochemical Society. “However, whilst ‘doubled’ could mean a risk increased from 25 per cent to 50 per cent, it could equally refer to 0.00001 per cent to 0.00002 per cent.” There are questions over whether the NHS has enough counsellors. One NHS source told New Scientist that there are about 200 genetic counsellors in England. To reduce the burden on the NHS, the Biochemical Society has suggested making firms release test results only through a registered clinical geneticist to give people the opportunity for advice and counselling at the time. The society also warned that laws may be needed to prevent DNA testing firms from passing data to health insurance firms, which could then use the results as a factor for determining insurance premiums. One survey by Genomics England found that 95 per cent of the UK public oppose the sharing of their genetic data with the insurance industry. The Department of Health said it couldn’t comment ahead of its green paper. ❚ Screening by fitness tracker could have unintended consequences, see page 23

Goodbye fishbowl helmet The next generation of astronauts will be wearing a zip-uppable “space hoodie”

Keep up with tomorrow’s tech today with New Scientist Sign up to a subscription today and you’ll also receive a free copy of New Scientist The Collection: The Quest for Space, featuring over 100 pages of in-depth articles on space exploration and the wonders of the solar system

For easy sign-up, visit

newscientist.com/13440 Or call 0330 333 9470, quoting reference 13440

News Solar system

Brexit

We could terraform Mars using a strange silica blanket

UK readying environment watchdog for no deal

Leah Crane

Adam Vaughan

NURTURING life on Mars may be as simple as bringing a thin blanket of superlight silica. Aerogel, a lightweight material made mostly of air, could be used to heat up the ground and protect it from harmful radiation while allowing enough light through for plants to grow. Mars poses two huge problems for life: it is very cold, with

THE UK government has begun preparations to have its planned environmental watchdog up and running within a month of a no-deal Brexit, a source close to the process has told New Scientist. In a sign of how seriously the government is taking the prospect of the UK exiting the EU without a deal on 31 October, work is under way to allow a version of the Office for Environmental Protection (OEP) to be rapidly set up to avoid a major hiatus in environmental protection. Government staff are already in place. “Plans are afoot to react to the political situation,” the source said, speaking on condition of anonymity. Environment secretary Michael Gove has said the independent watchdog, designed to take on the powers of European institutions over post-Brexit environmental breaches such as illegal levels of air pollution, will ensure a “green Brexit”. The OEP was originally planned to be ready by the end of the two-year

night-time temperatures plunging below -100°C in some areas, and it has no thick atmosphere to block damaging UV radiation. Robin Wordsworth at Harvard University and his colleagues have come up with a potential workaround using silica aerogel, which is one of the best thermal insulators we know of. They found that shining Mars-like levels of sunlight at an aerogel panel just 2 centimetres thick could warm the area below by more than 50°C. The material also blocked more than 60 per cent of UV radiation and more than 99.5 per cent of the most harmful type, UVC, while letting through the visible light necessary for photosynthesis (Nature Astronomy, doi.org/c8br). On Mars, the silica aerogel would probably have to be interwoven with other materials to build structures. It could be used to melt subsurface water down to depths of several metres, potentially starting a water cycle. “It has the advantage [over other terraforming proposals] that we could actually do it in the next few decades rather than much further in the future,” says Wordsworth. ❚ 14 | New Scientist | 20 July 2019

STEVE PARKINS/ALAMY LIVE NEWS

NASA

Making the Red Planet habitable might be easier than we thought

transition period if the UK-EU withdrawal agreement is passed by parliament. But there is an increasing prospect of the UK leaving the EU with no deal, as both Conservative party leadership contenders – one of whom will become prime minister – have indicated they are willing to do so. That would leave no enforcement bodies in place,

“Without a body to ensure compliance, we’ll end up with zombie legislation that doesn’t work” which Gove has said would be “suboptimal”. Ministers have suggested an interim secretariat could provide a holding role in the event of a no-deal Brexit. But a source with knowledge of the process now says a version of the OEP, not the interim body, would be ready within a month of no deal. “There is a plan in place to allow the requirements of the OEP to be delivered as quickly as possible as we exit,” they said. The urgency of establishing

the watchdog is to avoid the prospect of EU environmental laws being transposed to British law but – in the absence of an authority such as the European Court of Justice – without an enforcement body to back them up. “Without a body to ensure compliance and the regular updating of our laws, we’ll end up with zombie legislation that simply doesn’t work,” says Caroline Lucas, a Green party member of parliament. “It’s essential that preparations are massively accelerated to ensure the watchdog is ready and raring to go as soon as it’s needed, and that its powers are enhanced.” The Department for Environment, Food and Rural Affairs told New Scientist: “In a no-deal scenario, we will work to ensure that the OEP is in place as soon as possible, subject to the approval of parliament and the Environment Act receiving royal assent.” Establishing the OEP would require the government to publish its environment bill and pass it through parliament, potentially in October. While difficult, that is feasible, the source said. “The next prime minister must urgently bring forward an ambitious environment bill that can restore nature and tackle air pollution,” says Ruth Chambers of environmental coalition Greener UK. “To tackle the environmental crisis, the bill needs to establish legally binding targets and a strong new independent body to enforce them.” ❚ A new watchdog could help monitor breaches of air pollution limits

Palaeontology

A dinosaur’s dinner Unknown lizard species found in gliding raptor’s stomach

A NEARLY complete fossil of a lizard has been found in the stomach of a microraptor, a kind of feathered dinosaur that lived 100 million years ago. The unlucky animal must have been swallowed whole shortly before the dinosaur died and was fossilised. It was consumed head first, in the same way that many living birds and reptiles eat prey. The lizard is a previously unknown species and has been named Indrasaurus wangi by Jingmai O’Connor at the Institute of Vertebrate Palaeontology and Palaeoanthropology in Beijing and her team. The first part of its name refers to a Vedic legend in which a dragon swallowed the god Indra (Current Biology, doi.org/c77b). Microraptors had four wings thanks to feathers on their legs as well as their arms. They were capable of gliding and maybe even powered flight, says O’Connor. ❚

JINGMAI O’CONNOR

Michael Le Page

Energy use

Online video has a big carbon footprint TRANSMITTING and viewing online video results in 300 million tonnes of carbon dioxide being released a year, or nearly 1 per cent of global emissions. On-demand video services such as Netflix account for a third of this, with online pornographic footage generating a third too. This means online video has a carbon footprint equivalent to that of Spain. The findings come from French think tank The Shift Project. Earlier this year, it estimated that the production of all digital technologies and the power to run them was responsible for 4 per cent of greenhouse gas emissions and that this figure could soar to

8 per cent by 2025. Now it has estimated the CO2 emissions due to online videos alone. These accounted for 60 per cent of global data flows in 2018, its report states, or 1 zettabyte of data (1000 billion billion bytes). The definition of online video that it used doesn’t include live video streaming, such as Skype video calls or telemedicine, which accounts for another 20 per cent of global data flows. The move to ever higher resolution video will raise emissions further. So too could the launch of new game streaming services, such as Google’s Stadia, but the analysis didn’t try to estimate their impact.

The authors call for measures to limit the emissions from online videos, such as preventing them from autoplaying on web pages and only transmitting them in high definition when required. The estimates are broadly in line with others, says Chris Preist

60% Proportion of internet traffic that online video is responsible for

of the University of Bristol, UK, who studies the sustainability of technology. “This once again demonstrates the need for the designers of digital services to think carefully

about the overall impact of the services they provide,” he says. “For individuals, upgrading our devices less often, owning less devices and not demanding mobile, high-quality internet connection everywhere are probably the most important actions we can take.” To limit climate change, we need to reduce energy consumption as well as switch to renewables, says Maxime Efoui, one of the report’s authors. Limiting consumption is vital because building new energy infrastructure creates emissions, even if the electricity produced is eventually renewable, he says. ❚ Michael Le Page 20 July 2019 | New Scientist | 15

News Machine Learning

AI rakes in poker winnings A machine has beaten some of the world’s best poker players Donna Lu

We don’t know if there is a mathematically best poker strategy

Part of what makes poker so hard for AI to master is the huge number of possible moves, says Tristan Cazenave at Paris Dauphine University in France. There are more moves than there are atoms in the universe. Poker also involves hidden information, because a player has access only to the cards that they

20,000 An AI beat 15 top poker players over this many hands

see. This means an AI has to take into account how it would act with different cards so it doesn’t behave too obviously when it has a good hand. “If you look at real-world interactions, most of them involve hidden information, multiple participants or both,” says Brown. Pluribus learned to master the game by playing against five copies of itself. It started as a poker novice with no knowledge of the game, learning the rules over trillions of hands and improving

its strategy by reviewing the decisions it made every round. In games against five human professionals, Pluribus won by an average of 48 milli-big blinds per game – a measure of how many initial stakes were won on average per thousand hands of poker (Science, doi.org/c766). “You really want to push the AI, try everything you can to find a weakness,” says Jason Les, a professional poker player who was involved in the tournament. “Obviously we weren’t able to.” Although Pluribus beat human poker players, according to a game theory principle called the Nash equilibrium, there was no theoretical guarantee it would win, says Cazenave. A Nash equilibrium occurs when each player can’t improve on their performance by changing strategy. While there is an unbeatable Nash equilibrium strategy for Heads-Up Texas Hold ’Em, we still have no way of finding one for the six-player variant. “This is actually why the AI community finds this [victory] so surprising,” says Brown. ❚

classed as favourable, intermediate or unfavourable. Someone was considered to live favourably if they didn’t smoke, exercised for more than 150 minutes a week, had no more than one alcoholic drink a day for women and two for men, and ate a healthy diet. The team discovered that people with a high genetic risk of dementia had a 32 per cent lower chance of developing the condition if they

maintained a “favourable” lifestyle compared with an “unfavourable” one (JAMA, doi.org/c8bk). David Curtis at University College London points out that the study considered only cases of dementia diagnosed through hospital admissions and deaths. Llewellyn’s team admits some cases of dementia may have been missed because of this. Another limitation is that the genetic research was based exclusively on people of European ancestry, so the findings may apply only to this group. ❚ Adam Vaughan

CHARLIE RIEDEL/AP/SHUTTERSTOCK

ARTIFICIAL intelligence has finally cracked the biggest challenge in poker: beating top professionals at six-player, no-limit Texas Hold ’Em, the most popular variant of the game. Over 20,000 hands of online poker, the AI beat 15 of the world’s top poker players, each of whom has won more than $1 million playing professionally. The AI, called Pluribus, was tested in 10,000 games against five professionals, as well as in 10,000 rounds where five copies of Pluribus played against one professional – and did better than the pros in both. Pluribus was developed by Noam Brown of Facebook AI Research and Tuomas Sandholm at Carnegie Mellon University in Pennsylvania. It is an improvement on their previous poker-playing AI, called Libratus, which in 2017 outplayed professionals at Heads-Up Texas Hold ’Em, a variant that pits two players head to head.

Health

Healthy living lowers dementia risk regardless of genes PURSUING a healthy lifestyle may reduce your chance of developing dementia even if your genes make you more likely than other people to get the condition. The finding should encourage people not to be fatalistic if they have a family history of dementia. “One of the concerns is if you tell people to live healthily to reduce your risk of dementia, some people think they will probably develop 16 | New Scientist | 20 July 2019

dementia anyway because of their genetics,” says David Llewellyn at the University of Exeter, UK. Llewellyn and his colleagues followed about 196,000 people aged 60 and over with genetic data in the UK Biobank for eight years, during which time 1769 of them developed dementia. The team grouped everyone into three levels of genetic risk for dementia – low, intermediate and high – using previous work on associations between genetic variants and Alzheimer’s disease, a type of dementia. The people’s lifestyles were

“The finding should encourage people not to be fatalistic if they have a family history of dementia”

Marine biology

Analysis Drugs

Purple fairy wrasse discovered on ‘twilight zone’ reef

Most new drugs are no better than existing ones Healthcare systems need to do more to identify which therapies are worth paying for, finds Clare Wilson

Ruby Prosser Scully

LUIZ ROCHA/CALIFORNIA ACADEMY OF SCIENCES

Sometimes it can be hard to choose between similar drugs

PEOPLE IMAGES/GETTY

SCUBA divers have discovered a new fish – a vibrant purple fairy wrasse. They have named it Cirrhilabrus wakanda, after the fictional African kingdom Wakanda in Marvel’s Black Panther movie. The 6-centimetre-long fish (pictured below) has dazzling, deep purple fins and a yellow head. Luiz Rocha at the California Academy of Sciences and his colleagues found the fairy wrasse more than 60 metres under the ocean surface, swimming around in the coral reefs of eastern Zanzibar, Tanzania. The purple-streaked fish’s common name, the vibranium fairy wrasse, is a nod to the powerful, fictional, purple metal found in Wakanda and woven into the Black Panther character’s outfit. Just like the secretive nation of Wakanda, the fish were hidden somewhere in Africa isolated and unexplored – in this case Tanzanian reefs that are too deep for most recreational divers to explore. This meant the team had to use special equipment to reach the dimly lit “twilight zone” reefs where the fish were found. Several other species of fairy wrasse are known to live in stretches of water in the Indian and Pacific oceans, but DNA and morphology analysis confirmed that this one is a distinct species (ZooKeys, doi.org/c769). ❚

WHEN it comes to healthcare, new isn’t necessarily better. An analysis of 216 medicines launched in Germany since 2011 has found that only a quarter brought significant benefits over existing treatments, according to the available evidence. The rest had only minor or no benefits, or the impact of the medicine was unknown. Most of these drugs would have been available throughout Europe. Medical regulators expect firms to show that their products are safe and do what they are supposed to do. The standard way to do this is through a randomised controlled trial. However, pharma companies aren’t required to put prospective drugs up against the best possible treatment on the market. Instead, they may test them against placebo pills. Even when a new therapy is tested against an existing one, the old medicine may be given at too low a dose for a fair comparison. “That’s a problem, not only for pricing decisions but if a patient has to decide between one and the other,” says Beate Wieseler at the Institute for Quality and Efficiency in Health Care in

Germany, an author of the study (BMJ, doi.org/c77z). In cases where a new drug is truly better than existing ones, the benefit may be very small. This is particularly true for cancer treatments: a separate study of 72 cancer drugs launched in the US over 12 years found that, on average, they extended life by only two months. Richard Torbett at the Association of the British Pharmaceutical Industry disputes Wieseler’s findings. “Often, we find that studies making similar claims invariably take a very narrow view of what constitutes ‘value’ that ignores issues that are important to patients,” he says. To be fair, the pharma industry has delivered great benefits to health, including in the past few decades. Only 15 years after HIV was identified as the cause of AIDS in the 1980s, the industry had developed triple-drug regimens that give a nearly normal lifespan. We have recently seen an even more impressive turnaround with

a potentially deadly virus that causes hepatitis C. This infection can now be cured with a three-month course of treatment. So pharma firms are producing genuinely life-changing therapies mixed in with a larger number of also-rans. This is a big problem because all Western countries, whether their healthcare systems are funded by taxes or insurance, face rising medical costs, with a significant fraction of that due to increasing drug prices. This is why, in 1999, the UK set up the National Institute for Health and Care Excellence (NICE) to assess whether drugs are cost-effective, not just medically effective. Its decisions are sometimes unpopular, and politicians have even overruled them. In 2011, for instance, the government set up a special fund to pay for new cancer treatments rejected by NICE, which some argue was a waste of money. But the problem of ever-more expensive new medicines isn’t going away. Drug firms are increasingly painting regulators as barriers to life-saving treatments. They lobby for their products to be assessed under “accelerated approval” schemes, where less robust trial evidence is needed. A solution may be for politicians to take a firmer line, and work with regulators to demand better evidence before healthcare systems pay for new drugs. “Unless we address this, we are afraid the problem will become larger and larger,” says Wieseler. ❚

Read more online We may never know if a drug prevents Alzheimer’s newscientist.com/new-medicines 20 July 2019 | New Scientist | 17

News In brief Extinction crisis

Insect apocalypse may be unfolding in the US too

ROB LIPTAK, OHIO LEPIDOPTERISTS

BUTTERFLY numbers have dropped by a third in the past two decades in the US, echoing worrying declines seen in Europe. This raises fears for the health of insects more generally, because butterflies face similar environmental changes to this group of animals and are used as a proxy for studying them. To examine the fate of butterflies in the US, Tyson Wepprich of Oregon State University and his colleagues turned to the work of volunteers at the Ohio Lepidopterists. Members of this society have been collecting weekly data on sightings across the state over the past two decades. This is one of the most extensive insect monitoring programmes in North America. Overall, their records show the number of butterflies has fallen by 33 per cent. As temperatures increased over Chemistry

SOME of the innermost workings of molecules are being revealed for the first time. When they gain an electric charge, molecules can change structure, and now we can track these transformations. Shadi Fatayer and Leo Gross at IBM in Zurich, Switzerland, and their colleagues examined four substances using an atomic force microscope, which uses a tiny probe to build a detailed picture of a molecule’s atoms and bonds. To charge each substance, they ran a small voltage across the probe and the surface the molecule sat on, allowing the probe to transfer electrons to the molecule one at a time. The entire experiment was done in a very cold vacuum chamber to make sure the molecule was still and undisturbed by outside forces. “When we add or remove single electrons, we see how that changes 18 | New Scientist | 20 July 2019

Communication

the structure of the molecule,” says Gross. “We already knew that it happened, but not how the structure changes exactly.” In one compound often used in molecular machines, azobenzene, the work revealed that the whole molecule twisted. In another, pentacene, some areas of the molecule became more reactive. Tetracyanoquinodimethane changed the types of bonds holding its atoms together and moved on the surface it was placed on. In porphine, bond lengths and types changed (Science, DOI: 10.1126/science.aax5895). “Porphine is related to chlorophyll and haemoglobin so it’s very important in biology,” says Gross. “These molecules charging is what happens when haemoglobin transports oxygen in your body or when chlorophyll converts light into energy.” Understanding these effects could help us use such molecules more effectively, for example in nanomaterials. Leah Crane

Baad day? Goats can tell another’s lament A BLEAT may be just a bleat to us, but goats seem to recognise when one of their herd-mates is cheerful or down from their calls alone. When goats hear bleats that change in emotional tone, they look towards the source and their heart-rate readings show they are emotionally swayed by the noises. Luigi Baciadonna at Queen Mary University of London and colleagues recorded goats bleating

LINAS TOLEIKIS/GETTY

Mighty morphing atomic structures

the past 20 years, Wepprich and his team found that species from the south moved north into Ohio and were growing in number, while the number of northern species shrunk (PLoS One, doi.org/c75h). These changes suggest that some species are responding to ongoing climate change, says Wepprich. It wasn’t only rare and vulnerable species among the 81 covered by the study that were suffering. Wepprich says he was surprised that some common species that are adapted to live in humandominated habitat, like agricultural or urban areas, were declining. The researchers believe that habitat loss or fragmentation and changing agricultural practices have also probably made it harder for butterflies to survive. Ruby Prosser Scully

in different emotional states. To elicit positive sounds, they used goats that could see someone with a bucket of food. To get negative ones, they let a goat see another being fed while not getting any food themselves, or kept one in isolation for five minutes. Then, to a different goat, the team played a bleat every 20 seconds: nine positive followed by three negative or vice versa. At the start, the animal looked towards the noise, but this tailed off. When bleat emotion switched, the goat was more likely to look again – but only with the second of these calls. The team also tried to see how the listening goats felt, by looking at variation in time between each heartbeat. In people, a high value for this is linked to positive mood, while low values correlate with feeling depressed or stressed. Sure enough, when goats heard happy bleats, their heart-rate variability was higher than when they heard sad ones (Frontiers in Zoology, doi.org/c76r). Clare Wilson

New Scientist Daily Get the latest scientific discoveries in your inbox newscientist.com/sign-up Locomotion

Really brief

Jogging with straight arms is just as good

PLAINPICTURE

EVER tried running with your arms down? Most people find it hard, so it is a surprise to learn that it doesn’t require more energy than running with bent arms. Andrew Yegian and his colleagues at Harvard University recruited eight students to walk and run on a treadmill with their arms straight and bent. Six of the subjects also had their oxygen consumption measured. As you might expect, walking

Salt intake in China is one of the highest People in China consume 10 grams of salt a day on average, twice the World Health Organization limit (Journal of the American Heart Association, doi.org/ c77x). Too much salt can lead to high blood pressure. Over the past four decades, adults in China have had among the highest sodium consumption in the world.

with bent arms proved to be more energetically demanding than with straight arms, increasing oxygen consumption by 11 per cent. But, surprisingly, running with bent arms doesn’t appear to be more efficient than running with straight arms. The way we hold our arms is influenced by a trade-off between energy spent at the shoulder and the elbow, says Yegian. Bending the arms uses more energy at the elbow to resist gravity, but should save energy at the shoulder since it effectively makes the arm shorter, reducing the force needed to swing

Infants

Blue planet

How fish make leap from female to male

AI teaches doctors to spot viruses Artificial intelligence can spot previously unknown signs of cancer-related viruses. The new AI system can analyse images of tissue samples and identify signs of HPV, which can lead to cancer, with 89 per cent accuracy. It can also produce images that help doctors see signs of HPV (bioRxiv, doi.org/c773).

DALY AND NEWTON/GETTY

Whales whisper to their calves Southern right whale mothers and calves communicate using quiet moo-like calls to avoid attracting predators. Mia Nielsen at Aarhus University in Denmark and her colleagues found this by recording whales in Australia’s Flinders Bay (Journal of Experimental Biology, doi.org/c772).

the arms. The results for walking indicate that with bent arms, we spend more energy at the elbow than we save at the shoulder. As there was no difference in oxygen consumption while running, this suggests the tradeoff between shoulder and elbow energy is balanced (Journal of Experimental Biology, doi.org/ c76s). The study only tested running fairly slowly, so perhaps the benefit of bending our arms is only apparent at a higher speed. Running style might have links to the evolution of shorter arms in humans, says Yegian. Sam Wong

Mystery of pointing babies may have finally been solved BABIES in all cultures begin to point between the ages of 9 and 14 months, but the origin of this gesture has long been a puzzle. Some experts have suggested that pointing begins with reaching to grasp something. But there is good evidence that this is unlikely, says Cathal O’Madagain at the École Normale Supérieure in Paris. Instead, O’Madagain and his team suggest pointing comes from trying to touch with a fingertip. They say three experiments they carried out with groups aged 18 months to adulthood back up this idea. The first two tests revealed that all groups don’t necessarily angle

a pointing finger in a way that will direct another observer’s attention towards the object being pointed at. Rather, they appear to be reaching out to touch with a fingertip. The team’s third test explored how people interpret someone else’s pointing gesture. It showed that 18-month-olds and 3-yearolds – but not 9-year-olds and adults – understand pointing to be an attempt to touch an object (Science Advances, doi.org/c75j). “This allows us to put together a very different account of the origin of pointing – which is that pointing comes out of exploratory touch,” says O’Madagain. Adam Vaughan

CHANGING sex is part of life for many fish. For the first time, we have found out how one species, the bluehead wrasse, does it. Erica Todd at the University of Otago in New Zealand and her colleagues removed some male bluehead wrasse from reef sites off Key Largo, Florida. This triggers some females to change sex. They then caught changing females at regular intervals and looked at what was going on in their bodies. They found that the loss of males stresses some females. They become more aggressive and start performing male courtship behaviours. In individuals that become dominant in a social group, the genes associated with female hormones shut down in a day or two, and their colours begin to change – females are yellow and brown, males are green and blue. At the same time, the eggproducing tissues in their ovaries start to shrink and begin to be replaced by sperm-making tissues. In just eight to 10 days, the ovaries are transformed into testes, and the fish can mate with females and sire offspring. After about 20 days, they have full male colours and the process is complete (Science Advances, doi.org/c76t). Michael Le Page 20 July 2019 | New Scientist | 19

News Insight Climate change

Offsetting on your holidays About to jet off for a trip abroad? If you are planning to pay for carbon offsetting, buyer beware, says Adam Vaughan

20 | New Scientist | 20 July 2019

Flights are a major source of greenhouse gas emissions

JOCHEN KNOBLOCH/PLAINPICTURE

GRETA THUNBERG’S recent speech to the UK parliament was memorable not just for her oratorical firepower, but for how she got there: by taking trains from Stockholm to London, not a plane. The climate striker isn’t alone, as Swedes have driven the flygskam (flight shame) campaign. About 2000 people in the UK have pledged not to fly, while academics are being urged to fly less. But what if we still want or need to take the plane for work, holidays or meeting loved ones? The main option to assuage your guilt is carbon offsetting, where the amount of carbon you emit from an activity is negated by an equivalent reduction of carbon emissions elsewhere, through reforestation, renewable energy or other projects. Countries are also trying to decide what role offsetting plays in a post-Paris climate deal world, and many airlines will soon be required to offset any emissions growth. But does offsetting have a legitimate role to play in tackling climate change, given that it does nothing about our past emissions or cutting our ongoing footprint? Many observers say offsetting still serves a purpose. “I like to start with what we need to do,” says Niklas Hagelberg at the United Nations Environment Programme. The UN’s Intergovernmental Panel on Climate Change says that if temperature rises are to be limited to 1.5°C, emissions must nearly halve by 2030 and decrease almost entirely by 2050. Offsets can balance activities with few alternatives, says Hagelberg – in his case, flights from Nairobi to see family in other countries. But he says they are only useful if you also halve your carbon footprint in the next 11 years, so he is cutting

emissions using solar heating and electricity at home. Benjamin Sovacool at the University of Sussex, UK, says if people are going to fly, it is good to offset, but better still would be not flying, or taking the train. What we really need to do is change our behaviour, but Sovacool’s research has shown

“Offsetting risks the rebound effect: people feel they can eat meat or drive a petrol-guzzling car” that people are unlikely to do so unless politicians force them. Offsetting also carries the risk of the rebound effect, in which people feel that because they offset, they can eat more meat or drive a petrol-guzzling car, he says. The truth is, most of us aren’t doing anything about our emissions at all. The amount

of voluntary offsetting, such as the sort you might take out for a flight, is surprisingly small. Since 2005, the world has voluntarily offset just 430 million tonnes of carbon dioxide, equivalent to Australia’s energy-related emissions in 2016. Only about 1 per cent of passengers offset their flights through airlines’ voluntary schemes, according to the International Air Transport Association (IATA). A recent report found that half of the big airlines don’t even offer such a scheme. The aviation industry is keen to stress that offsetting is a stopgap until it can bring in new engine technologies and lower-carbon fuels, which it expects in the 2040s (see “Green skies ahead”, right). “Carbon offsetting for us has always been conceived as a temporary measure,” says Michael Gill of the IATA. From 2021, many airlines will have to offset any

growth in emissions – although not their existing emissions – as part of a UN-brokered deal. But if you are going to offset, what should you look for when you want to neutralise a flight, or even your entire lifestyle? How do you know what is effective? “That’s where it gets much more murky. There are boundless different schemes,” says Hagelberg. He recommends that people use ones that have been certified by a third party such as Gold Standard, a Switzerland-based foundation. It excludes high-risk project types that might not deliver real negative emissions, such as large-scale hydropower, and favours those that are monitored, independently verified and engage local people. One key issue is “additionality”: whether a project would have happened regardless, without offsets, which is notoriously hard to prove. For example, Gold Standard is considering limiting eligibility for some renewable energy projects in high and middle-income countries. That is because while a wind farm in India in the past may not have been built without money from offsetting, today they are financially viable, says Sarah Leugers at Gold Standard. Kathrin Dellantonio of Swiss offsetting company MyClimate says third-party certification and monitoring schemes can make offsets more expensive, but are worthwhile. “Unfortunately, high-quality carbon offset projects according to strict standards can be confused with low-quality CO2 offsets,” she says. It may be worth choosing an airline with newer, more efficient

Working hypothesis

More Insight online Your guide to a rapidly changing world newscientist.com/insight

be misused by people who want to misuse them, and therein lies the danger,” he says. Kevin Anderson at the Tyndall Centre for Climate Research in Manchester, UK, is more damning. He says he would never offset, because it doesn’t address past emissions and, in the long term,

430m The tonnes of carbon dioxide voluntarily offset since 2005

the carbon may not stay offset. “In the end, offsetting typically contributes to locking in a highcarbon infrastructure,” he says. The evidence is mixed for whether offsetting delivers the carbon balancing it promises, says Sovacool. It is dependent on the design of the programme, the scale

AIRBUS

Green skies ahead There is no such thing as a green flight, yet. Yes, a tiny battery-powered plane (pictured right) has crossed the English channel and a solarpowered one has flown around the world. But the energy density and weight of the thousands of lithium-ion batteries needed to achieve flight mean that most aviation experts think that electric planes are still decades away. The UK government’s climate change advisers think passenger planes using a hybrid of oil and batteries won’t materialise until the 2040s, with the first “fully zero-carbon plane” coming post-2050. The air industry is pinning most of its hopes on sustainable fuel alternatives, such as ones from crops or plant waste.

Yet there have been some recent green shoots for electric planes. During the Paris Air Show last month, UK-based firm Rolls-Royce, which has a concept electric vertical take-off and landing vehicle, bought Siemens’ electric aircraft business. Regional US airline Cape Air said it would order “double-digit” numbers of a nine-seater electric plane made by Israeli firm Eviation, which is reportedly capable of flying more than 1000 kilometres. There are now 170 electrically propelled aircraft in development globally, up 50 per cent on last year. But long haul, high volume electric planes are still a long way from taking off.

and location, he says. For example, some are concerned about tree planting, saying there is no guarantee of the trees’ longevity. If they are cut down, the carbon locked inside could be released. That is one reason why forestry projects make up only a small proportion of offsetting projects. The UN’s Clean Development Mechanism (CDM), the world’s biggest offsetting scheme, is considered one of the most thorough in terms of monitoring, reporting, verification and transparency. But even that has been found to be flawed. A 2016 report by the Institute for Applied Ecology in Germany claimed that 85 per cent of the CDM projects it looked at had a “low likelihood” of delivering a real reduction in emissions. For now, the scale of the climate change challenge means there is still a need for offsetting alongside emissions reductions, says David Abbas at UN Climate Change, which runs the CDM. “We need more mechanisms like the CDM, not fewer,” he says. But the window of opportunity is closing. All countries need to have reduced emissions to net zero by 2050 to avoid dangerous warming, so although there will be offsetting between sectors within national borders, there will be little scope for offsetting in poorer countries as there is today. Depending on how sensitive the climate is to greenhouse gases and how accurately we have modelled carbon budgets, that date might even be earlier. Meanwhile, as technology advances, it is already becoming harder to find projects where additionality can be proved, as Gold Standard’s proposal for wind and solar shows. Mason puts it simply: “We are heading to the end of the road for offsets.”  ❚

▲ Break the mould A paper titled “Fantastic yeasts and where to find them” forced us to accept that punning study titles can (occasionally) be good. ▲ Mind over matter Wimbledon men’s singles champion Novak Djokovic convinced himself the crowd was cheering his name not that of his opponent. Nice job Roger! ▼ It’s fine A $5 billion fine for privacy-related bad behaviour is such small change for Facebook that its stock price actually went up after the news. ▼ #StormArea51 Half a million people have signed up to storm Area 51 in September. It will be a tough task because the base contains [REDACTED]. BOTTOM: ESA-P.CARRIL TOP: GETTY

planes where possible. For example, offsetting a return flight from London to New York costs £44 via MyClimate’s own website, based on industry averages, while a scheme it runs for German airline Lufthansa will offset the same flight for £12, because the firm has a more modern fleet than the industry average. “I think that there are some really brilliant carbon offset schemes that do amazing things, many of which go well beyond carbon,” says Mike Mason, founder of UK offsetting company ClimateCare. “The problem is there is an awful lot of crap out there [too].” He sold his firm to J. P. Morgan in 2008, partly because the market was flooded with cheaper, inferior schemes, he says. One of Mason’s other concerns is that offsetting is often used as an excuse for polluting as usual, a long-standing criticism. “They can

Sorting the week’s supernovae from the absolute zeros

▼ Sat-naff Some smartphones in Europe will have to rely on Chinese, Russian or US satellites after a fault with the European system Galileo. Magnifico.

20 July 2019 | New Scientist | 21

SOUVENIR ISSUE

MOON LANDING 5OTH ANNIVERSARY 1969-2O19

THE QUEST FOR SPACE

Don’t miss a special souvenir issue from New Scientist celebrating the 50th anniversary of the moon landings. Explore the past, present and future of space exploration with over 100 pages of in-depth articles on the wonders of the solar system, plus 20 pages of newly resurfaced historical content from New Scientist’s archive detailing the original space race as it happened

Available from all good magazine retailers, digitally in the New Scientist app or direct from

newscientist.com/thecollection

Views The columnist Graham Lawton on the first ever National Park City p24

Letters Understanding the ninth wonder of the brain p26

Culture Our pick of the best summer reading and listening p28

Aperture The colourful delights of a tree exhibition in Paris p30

Culture columnist Chelsea Whyte is starry-eyed for real Apollo tales p33

Comment

Heart on your sleeve Fitness trackers that let you self-screen for heart conditions risk doing more harm than good, argues Margaret McCartney

JOSIE FORD

S

ELF-EMPOWERED, selfmotivated, self-aware: we have got used to the idea that more knowledge about our health is good for us. This ethos has fuelled an explosion in wearable technologies – fitness trackers, step counters and other gizmos – that give us real-time feedback on key physiological stats such as heart rate. Recently, the makers of the bestselling fitness tracker, the Apple Watch, began to roll out a new feature: the ability to monitor heart rhythm, and specifically to detect atrial fibrillation. Atrial fibrillation is a relatively common heart condition in which the two atria of the heart – the

upper chambers – don’t contract regularly. It can be constant, or intermittent, and becomes more common with age. It increases the risk of blood clots forming and causing a stroke. Those with the condition may need medication to thin their blood and allow their hearts to work efficiently. So why wouldn’t you want to know if you had it? Certainly, some doctors I have spoken to welcome the diagnostic possibilities that wearables bring; many are enthusiastic users themselves. The problem is that this is mass screening via the back door, with all the associated positives and negatives. At its best, screening finds diseases at an early stage so

that adverse consequences can be avoided. At its worst, it causes far more damage than the disease itself through false positives and unnecessary worry and treatment. In the UK, the National Health Service follows evidence-based recommendations made by the National Screening Committee. Its current advice is clear: don’t screen for atrial fibrillation. That is because we have evidence that treatment works for people with symptoms, or those found to have the condition while being assessed for another condition. There is no evidence that treatment benefits outweigh the risks for a wider, asymptomatic population.

A recent US paper suggests that 10,000 asymptomatic older people would have to be screened to detect 50 people with atrial fibrillation, and all those 50 would have to be treated to prevent one stroke. Meanwhile preliminary results of one study, funded by Apple, find that diagnoses of atrial fibrillation could be confirmed by a subsequent electrocardiogram only in about a third of cases. All this matters because the side effects of the blood thinners used to treat atrial fibrillation can be severe, ranging up to bleeding into the brain or gut. Such treatment would of course only be prescribed after consultation with a doctor. But if you are already finding it difficult to get a doctor’s appointment, think of the impact of a lot of false positives landing on their desk. In the UK, the SAFER (Screening for Atrial Fibrillation with ECG to Reduce stroke) study is getting under way to test whether mass screening for atrial fibrillation is useful, with ethics committee oversight and informed consent. In the meantime, if you have symptoms – breathlessness, chest pain – you should see a doctor. If you want to be screened, enter a trial. Just because early detection sounds sensible doesn’t mean it is good for us. ❚

Margaret McCartney is a GP and commentator based in Glasgow @mgtmccartney 20 July 2019 | New Scientist | 23

Views Columnist No planet B

All hail the urban jungle Cities should take their rightful place in the pantheon of places valued for their ecosystems and biodiversity, writes Graham Lawton

I

Graham Lawton is a staff writer at New Scientist and author of The Origin of (Almost) Everything. You can follow him @grahamlawton

Graham’s week What I’m reading I’ll be on holiday when this is published. I’ll take an improving book but will probably end up with a trashy novel. What I’m watching Something or other on Netflix. Probably also trashy.

This column will appear monthly. Up next week: Annalee Newitz 24 | New Scientist | 20 July 2019

NICOLASMCCOMBER/GETTY

What I’m working on My tan.

’VE lived in cities all my life and have always felt that the urban environment is my natural habitat. I never imagined I’d end up living in a national park. It turns out that I was wrong. Well, sort of. No, I’m not moving to the country. It is moving to me. On 22 July, London will become the world’s first National Park City. When I moved here nearly 30 years ago, I discovered that Londoners are given to boasting that their city is the greenest in the world. If you amalgamated all the green spaces – parks, squares, gardens, woods, allotments, sports pitches, marshes and churchyards – it is said that they would add up to about half of the city. That isn’t quite true. Figures compiled by the World Cities Culture Forum show that public green space actually covers 33 per cent of London, a middling figure bettered by Sydney, Stockholm, Oslo, Vienna, Singapore and even Los Angeles. But it isn’t to be sniffed at: Istanbul manages just 2.2 per cent and Tokyo 7.5 per cent. The declaration of National Park City status is an achievement for those who have campaigned for it for years. But it doesn’t carry much official weight. London hasn’t been added to the UK’s 15 official national parks. There was no public inquiry or order from the environment secretary, as is required to create one. London has effectively bestowed the status upon itself. But movements have to start somewhere, and the city’s elected leaders have committed to deeds as well as words, including a pledge to plant more trees and create more green spaces. The city’s biggest car-free day yet will happen on 22 September. Residents of the UK’s actual national parks may look down their noses on London as a vulgar

urban gatecrasher to their refined country club. But magnificent as parks like the Lake District and South Downs are, the truth is that they are often managed more for people than for wildlife. The Lake District, for example, has been called a “sheepwrecked wasteland” and a “monument to subsidised overgrazing and ecological destruction”. Three-quarters of its supposedly protected nature areas are in poor condition. In comparison, the UK’s cities are biodiversity hotspots and home to vibrant ecosystems. The fact that they are largely artificial ecosystems doesn’t

“I’m not moving to the country, it is moving to me when London becomes the world’s first National Park City”

matter. So are the rainforests on most tropical islands. Visit the Seychelles or Hawaii and what looks like native forest is actually a hotchpotch of mostly invasive and introduced species. London’s parks and gardens are full of exotic plants, its waterways teem with Chinese mitten crabs and its skies are full of parakeets from the foothills of the Himalayas. Native species are faring well too; if you want to see a wild fox in the UK, I’d recommend a safari to my local kebab shop rather than a trip to the countryside. From the perspective of biodiversity and ecosystem services – the economic value

of nature – the fact that you have a lot of non-native species matters little. Increasingly ecologists say there is no such thing as a pristine ecosystem; what matters is its functioning as a whole. Yes, some invasive species are a threat to native biodiversity – mitten crabs, for example – but most aren’t. London can also be compared to what ecologists call “cultural landscapes” – human-created wild spaces such as the Côa valley in Portugal. These are mosaic landscapes with a mixture of  woods, open spaces and waterways, rich in biodiversity but dependent on humans to keep them that way. Rewilding projects often aim to maintain these landscapes that would otherwise be lost if they were actually left to run wild. That should be London’s goal – to create and manage a mosaic urban ecosystem that makes good on its boast to be the greenest city in the world. Let’s call it urban rewilding. Of course, big cities have environmental problems. London’s include a transport system that is often reliant on fossil fuels, dreadful air pollution and a built environment that still relies too heavily on concrete, steel and glass. The proposed third runway for Heathrow airport would make a mockery of any green aspirations. If National Park City status is to mean anything, it must create impetus and authority to confront those problems. In an increasingly urbanised world – more than half of people now live in cities – the urban environment is vital to creating a sustainable future. It is easy to be cynical about London’s selfdeclared status, but I’m proud to live in the world’s first National Park City, and urge other big cities around the world to join us. ❚

RESERVE YOUR FREE TICKET AT: tiny.cc/17ti9y

Small Talk

WHAT SHOULD WE EAT TO SAVE THE PLANET? Monday 22 July 2019 3pm Regents Place NW1 3BG London

Join us for a free talk on the future of food, with exotic samples. will we eat locusts for breakfast? the meat you can include in a sustainable diet tips for a planet-saving lifestyle

SPEAKER: Ursula Arens nutritionist, writer and member of the British Dietetic Association

Part of the London Green Film Festival 17-26 July, screenings daily 12:30 & 6pm More at: www.regentsplace.com/greenfilmfest

Views Your letters

Understanding the ninth wonder of the brain 22 June, p 34 From David Werdegar, Naperville, Illinois, US You describe eight wonders of the human brain. There is a ninth, without which the other eight would be trivial: our absolute dependency on the signs and symbols of language. Our internalisation of the world around us, substituting symbols for reality using rules adopted by each culture, has become so taken for granted that we may not realise it is impossible for us to think without language. So dependent are humans on this to get through the day, from waking to sleeping, that linguists and ethnologists have long argued that animals lacking language skills can’t truly conceptualise as we do. Much work is needed for us to understand how we seamlessly link the language areas in our brain with our intent areas. If I want to have a drink with breakfast (and that choice is itself language-dependent), how do my brain’s action centres access my language centre to decide whether it will be coffee or tea? Defining this pathway in great detail is the holy grail for understanding the mechanism of our mind.

Safety dies in the crossfire of privacy and security 29 June, p 14 From Daniel Dresner, Manchester, UK Donna Lu is right to raise concerns about privacy in the security industry. She went to the IFSEC security conference in London: such exhibitions are where the new and shiny reign. A colleague of mine also attended IFSEC and carried out a straw poll of vendors on the internal security of their internet-connected devices. He found only one product for which basic security practices, such as the ability to update when 26 | New Scientist | 20 July 2019

inevitable software flaws create vulnerabilities, appeared to have been accounted for. I took part in a panel discussion where the audience descended into group therapy, as it became apparent that only the converted had stayed on. I was shocked by one self-confessed entrepreneur whose attitude was that security is for someone else to worry about in the “next generation”. For him, the opportunity is to sell the product now, however flawed it is. Perhaps we should learn from the languages in which “safety” and “security” are the same word.

Camouflage may deceive more than one enemy 29 June, p 9 From David Aldred, Brough, East Riding of Yorkshire, UK A recent article mentions that the US Navy may wish to convince enemy forces that, for example, a Honda Civic car is a tank, or vice versa. To me, this sounds like an ideal excuse for any player with malign intent to blow up absolutely anything they want. They can then declare: “Our AI assured us the target was a

military installation, though it was later established to have been a basket of kittens.”

Sunshine exports are limited by water supply 8 June, p 20 From Chris deSilva, Perth, Western Australia James Mitchell Crow suggests that Australia can stay competitive only if the country becomes a hydrogen producer and exporter. But production of hydrogen by electrolysis requires large quantities of electricity and fresh water. Australia’s sunshine and wide open spaces do have the potential to produce electricity from solar and wind power, but the availability of fresh water is another matter. The regions of Australia best suited to solar and wind power generation are desert. The rest of the continent is susceptible to prolonged droughts. Even when there is no drought, water is in short supply. I live in Perth, where annual rainfall has declined over the past 50 years and the catchment dams are usually well below capacity, even at the end of

winter. The city’s water supply and, indeed, its survival depend on a dwindling groundwater resource and desalination. Exporting hydrogen is, in effect, exporting water – something the nation can ill afford to do.

There are more creatures that make milk-like stuff 8 December 2018, p 20 From Gerald Legg, Hurstpierpoint, West Sussex, UK I was interested to read your report on spiders that produce nutritious milk-like fluids, which said “milk secretion is exclusive to mammals”. I work on pseudoscorpions, which, like spiders, are arachnids. They don’t lay eggs but possess sophisticated reproductive strategies that involve embryos and larvae being attached to the mother’s genital aperture in a brood sac. She feeds them with nutritive fluid, that is to say, “milk”. This is necessary because the yolk of pseudoscorpion eggs has a deficiency that needs to be made up. This is accomplished by the ovary, which cycles through four phrases: resting, preparatory,

secretory and renovation. In the secretory phase, it produces a nutritive fluid containing proteins and phospholipids, which is extruded into the brood sac and ingested by the developing embryos and larvae. In the first of its two moults, an embryo develops a pumping organ, which enables it to absorb nutritive fluid and later forms the mouth region. This is analogous to the mammalian teat, but instead of being on the mother, each embryo has its own.

Have your inconvenience now and avoid it later 22 June, p 20 From Krista Nelson, Hobart, Tasmania, Australia Chelsea Whyte mentions that many people resented the disruption that the Extinction Rebellion protests created because they “felt the inconvenience didn’t justify the cause”. I think this sums up the global attitude to action on climate change. Maybe people need to be reminded of the inconveniences that global warming will cause. Instead of stopping trains, perhaps future protests should cordon off low-lying coastal areas and hand out flippers and snorkels to those who want to enter? Any complaints can be met with a polite reminder that this will soon become a permanent inconvenience.

What citizens’ bodies can decide on carbon taxes? Letters, 15 June From Simon Goodman, Griesheim, Germany Paul Whiteley claims the reason for the anger of the gilets jaunes protesters in France was the “incompetent and arbitrary” imposition of fuel taxes by

president Emmanuel Macron. I, too, hate taxes, but they will support progress against climate change, which is hardly a “nebulous concept”. Fuel taxes have been shown to be a necessary and potentially egalitarian way to influence climate change. Whiteley also wants “Citizen Councils”. That evokes the history of soviets (workers’ councils) in Stalin’s Russia and similar systems in Mao’s China. They are not to be confused with necessary consultative public involvement. It is bizarre to claim that ordinary people, whoever they might be, are in the best position to judge what is morally acceptable to them. Until 2015, opinion polls showed that the UK public saw judicial murder by hanging as desirable, yet parliament abolished it in 1965 as it had no effect on murder rates. From Chris Sheppard, Ulladulla, New South Wales, Australia Calls to replace politicians selected by the people with informed benevolent dictatorship (as in the Citizen Councils that Whiteley says Extinction Rebellion wants) have been made before by those with simple solutions to complex problems. The Russian Revolution comes to mind. The editor writes: Extinction Rebellion in fact demands a “citizens’ assembly” that would make proposals to the elected government.

The prospects for methane in our atmosphere Letters, 15 June From Guy Cox, St Albans, New South Wales, Australia Bryn Glover says that because humanity has only a couple of decades to get its act in order, we need to pay much more attention

Want to get in touch? Send letters to New Scientist, 25 Bedford Street, London WC2E 9ES or [email protected]; see terms at newscientist.com/letters

to the short-term effects of methane emissions. We do have around 20 years to avoid reaching a tipping point that is followed by runaway climate change. But that doesn’t mean the polar ice caps will melt in two decades’ time. It means that we will have put enough carbon dioxide into the atmosphere to ensure that this will happen within the next few centuries. Methane has a higher greenhouse effect than carbon dioxide in the short term, but it is converted to CO2 and water in the atmosphere, so its long-term effects are exactly the same. From Roland Crothers, Somerton, Somerset, UK Glover says tackling methane emissions should be a priority. Can a reader tell me if there is any possibility that methane released from melting permafrost could be harvested and used as an energy source? This would also unburden the atmosphere of a potent greenhouse gas.

Find a wad, give it back, hope for a reward 29 June, p 17 From Georgina Skipper, Weymouth, Dorset, UK So people are more likely to return a wallet with about £70 in it than about £10. I fear this is more easily explained by considerations other than altruism and moral probity. When my brother returned a wallet he found containing £100, which was a fabulous sum to a small boy in 1970, he rather expected to be offered a small reward. None was forthcoming, but even today, I imagine people would hope to receive about 10 per cent… and 10 per cent of £10 is only £1. Hardly worth the bother.

as an athlete, bemoaned the lack of fitness among his students”. But Plato recorded in the Symposium that it was at the gymnasium that Alcibiades tried to seduce Socrates, saying: “he trained and wrestled with me”. Being athletic, even if you were celebrated for philosophy rather than for winning laurel crowns at the Olympics, was important to Greeks of his era and class.

Drug tests are biased on age and complexity too 15 June, p 23 From Annette Lane, Anse, France I agree with Caroline Criado-Perez that women are often not included in clinical trials and obviously have different reactions from men. Furthermore, most drugs are tested only on those under 70 who have just one medical condition. Many drugs for diabetes and heart conditions, for example, are taken together, by people over 70 whose immune systems aren’t functioning as well and whose livers are generally less able to cope with drug elimination. Has anybody looked into this?

Sorry, you have no choice but to read this 15 June, p 30 From Larry Blood, Wellington, New Zealand Hannah Critchlow’s book The Science of Fate argues for the absence of free will. I presume that her genes, environment and circumstances made it inevitable that she would write a book. It would also be inevitable that such a book would deny the existence of free will, that I would be doomed to write this letter to point that out and that you would be compelled to publish it. ❚

The philosopher Socrates was no couch potato

For the record

15 June, p 34 From Leslie Wilson, Reading, Berkshire, UK Herman Pontzer writes that “even Socrates, not remembered

❚ The striatum is a collection of brain structures, including the basal ganglia, and the primary motor cortex is nearer the front than we showed it (29 June, p 38). 20 July 2019 | New Scientist | 27

Views Culture

Serious, sublime and... skin Why are squid eyes so big? What is Caesar’s novel? Can von Humboldt go graphic? New Scientist picks the best summer reading and listening

Psychology

How To Do Nothing: Resisting the attention economy THERE is no shortage of books about digital culture and its deleterious effects. The same goes for publications on healing our addicted and distracted minds or that recommend contemplating nature as a mental salve. How To Do Nothing is different. Author Jenny Odell calls it “an activist book disguised as a selfhelp book” and explains why “in an environment completely geared toward capitalist appropriation of even our smallest thoughts… doing nothing is hard”. The attention economy is well served by technology but isn’t driven by it. As Odell reminds us, around 306 BC, the Greek sage Epicurus set up his philosophical school on the outskirts of Athens to avoid the centre’s opportunism, corruption, machinations and military bravado. From a couple of millennia later, she quotes Scottish writer Robert Louis Stevenson, who called busyness a “symptom of deficient vitality”, and observed “a sort of dead-alive, hackneyed people about, who are scarcely conscious of living except in the exercise of some conventional occupation”. What to do? Groups resisting a prevailing cult of urgency quickly become their own little fiefdoms, ruled over by their own little philosopher-kings. Individual acts of resistance, on the other hand, rarely achieve scale. We admire the polite obstructionism of the clerk in Herman Melville’s short story Bartleby, the Scrivener. But the poor devil still ends up dead in jail. 28 | New Scientist | 20 July 2019

PLAINPICTURE/ANDRÉ SCHUSTER

Jenny Odell Melville House

Odell argues that turning our backs on social media to engage with our immediate environment and its plight may offer us a third, more effective line of resistance. Stirring stuff. Simon Ings Evolutionary biology

Good Enough: The tolerance for mediocrity in nature and society Daniel S. Milo Harvard University Press

The eyes of giant and colossal squid grow up to 40 centimetres in diameter, the largest in nature. Why? No adaptive advantage has been found for such huge, expensive jellies. And what about the giraffe? “It could be that giraffes evolved long necks to outdo other browsers,” argues philosopher Daniel Milo, “but there is no reason... giraffes should rise two meters above their tallest competitor, the African elephant.”

Good Enough wonders why evolutionary biologists shun the scientific thinking called the null hypothesis. This states, says Milo, that “every relationship between phenomena is, by default, the fruit of chance”. If you think the squid needs big eyes, or the giraffe a long neck, prove it. If you can’t, then chance is a sufficient explanation. “Most of what survives was not selected but is just not bad enough to be eliminated,” Milo observes. Some of nature’s wonders might be happy accidents, rather than masterpieces of adaptation. The human brain is one such. For most of our history we have been an endangered species – the only

“Most of what survives was not selected but is just not bad enough to be eliminated”

one that gives birth two months later than we physically should, to infants that are “neurologically half-cooked”. The intellectual gifts our brains provided were barely enough to drag us, 70,000 years ago, through a population bottleneck that may have seen human numbers fall to 10,000. Today, coddled in a warm bath of culture, our brains are no longer useful, says Milo: they just are. “The skills our ancestors cultivated for the purpose of survival no longer serve that purpose,” he writes, from the perspective of 21st-century plenty, “yet the skills remain.” The “antiboredom project” we call culture, thrives not because it is selected for through struggle, “but because there is no struggle”. It is a charming argument, suited to lazy, sunny afternoons: “Why should we struggle and strain when we are all good enough?” SI

Don’t miss

Medicine

The Remarkable Life of the Skin: An intimate journey across our surface Monty Lyman Bantam Press

“When you look closely at the back of your hand, it is as if you are in a passenger aircraft peering down at the world from 30,00 feet,” writes dermatologist Monty Lyman in one of the few books to tackle skin, our largest, most visible organ. And somehow you know exactly what he means. Liz Else Science thriller

Eight Lives Graphic novel

The Adventures of Alexander von Humboldt Andrea Wulf and Lillian Melcher Pantheon Books

Alexander von Humboldt was one of the greatest scientists of all time, a polymath and explorer who paved the way for Darwin and foresaw climate change and environmental destruction more than 200 years ago. Andrea Wulf won an award for her biography of him; now she has teamed up with artist Lillian Melcher to create a wonderful, rich graphic novel of Humboldt’s incredible life. “I fear that one day man will travel to distant planets,” wrote Humboldt. “And then he’ll take his lethal mixture of vice, greed, violence and ignorance to those planets too – turning them barren and ravaged as we are already doing with Earth.” Humboldt saw nature as a living whole, a “wonderful web of organic life”,

Susan Hurley Affirm Press

An Australian science thriller that centres on an immigrant doctor and a clinical trial that goes horribly wrong. This has its origins in the real-life horror story of the 2006 UK clinical trial of autoimmune drug TGN1412. Donna Lu Synthetic biology

The Age of Living Machines: How biology will build the next technology revolution

Climate science

Watch

Vanishing Ice: Glaciers, ice sheets, and rising seas

The Current War, in UK cinemas from 26 July, stars Benedict Cumberbatch as Thomas Edison and Michael Shannon as George Westinghouse in a story about the 19th-century race to electrify the US.

Vivien Gornitz Columbia University Press

The world is melting. We are on a terrifying path towards the eventual loss of the cryosphere, that part of our world made of ice and snow. Geologist Vivien Gornitz describes all aspects of the science of the thawing world, and of the ecological, climatic, social and economic consequences. Read it, and act before it is too late. RH Sci-fi

Semiosis Sue Burke Macmillan

Catch up with the first of two connected novels before the next, Interference, in late autumn. Imagine Kim Stanley Robinson’s Mars Trilogy – but with sentient alien plants. Gripping and strong on biology and consciousness. Ruby Prosser Scully Puzzles: Code and ciphers

Read

The Future of Immortality: Remaking life and death in contemporary Russia by Anya Bernstein (Princeton University Press) explores the lively present and deep past of some futuristic Russian research.

Conundrum: Crack the ultimate cipher challenge! Brian Clegg Icon Books

Just the thing for a very, very long train journey: a book of fiendish cryptic puzzles and ciphers. Start with Caeser’s novel and end with Enigma variation. Good luck! LE

Susan Hockfield W W Norton

Podcast

Visit

Science Vs

Want to learn how to build a better battery with viruses? How plants are being re-engineered to produce more food? Or how computers will interface with our brains? Your amazing guide to the future of biology is the former president of the Aladdin’s cave that is the Massachusetts Institute of Technology. RH

Gimlet Media

Sean Lynch: A murmur, repeated opens at the John Hansard Gallery in Southampton on 20 July. Lynch’s delirious installation imagines the reactions of a 17thcentury poet to a world of mobile phones, plastic and identikit motels.

The Science Vs team aims to put us right by sorting out what is fact, what isn’t and what is in-between for faddish topics. Hosted by Wendy Zuckerman, the team tackles DNA kits, alcohol and fasting diets. Great fun, offering episode transcripts often featuring more than 100 citations.

20 July 2019 | New Scientist | 29

SEAN LYNCH, A MURMUR, REPEATED, 2018–19. VIDEO STILL. COURTESY RONCHINI, LONDON

describing it without resorting to God. After Wulf’s mission to elevate Humboldt to his rightful place, this beautiful book should bring him to a new audience. Rowan Hooper

LUIZ ZERBINI, COISAS DO MUNDO, 2018, ACRYLIC ON CANVAS, 250 × 361 CM, ARTIST’S COLLECTION, RIO DE JANEIRO, BRAZIL © LUIZ ZERBINI PHOTO © PAT KILGORE

Views Aperture

Luis Zerbini, Coisas do Mundo, 2018

30 | New Scientist | 20 July 2019

Root and branch Exhibition

Trees Fondation Cartier, Paris Until 10 November

“IT’S very chaotic,” says artist Luiz Zerbini, gesturing at this huge, colourful and joyful canvas, on show at the Trees exhibition in Paris. Crammed with the leaves, fruit and trunks of trees native to his home, Brazil, at first glance it seems to celebrate the riots of nature, free of people. But closer inspection of his canvases reveals humanity’s fingerprints, from a digger lifting a palm tree to plastic bottles on sticks. “I think it’s a reflection of the place I live. Rio de Janeiro has a huge forest just inside of the city. Everything is mixed. It’s an urban landscape, but it’s really full of nature,” says Zerbini. Unsurprisingly for a selfprofessed lover of plants, Zerbini despairs at the accelerating deforestation of the Brazilian Amazon under President Jair Bolsonaro: “We are living in a terrible time.” Bolsonaro’s plan to grow the economy by clearing forest to grow soya beans is “very stupid”, he argues, because Brazil’s riches are in its natural world. Our very different relationships with trees are at the heart of this exhibition. Some pieces are humorous, like Sebastian Mejia’s photographs, which show the strange ways we fit trees into our cities. In one, a tree emerges through the roof of a petrol station in Chile. Some of the artworks are by people with scientific credibility, such as biologist and botanist Francis Hallé, whose pencil and ink drawings have a Japanese flavour (see page 32, bottom right). Others use a more naive style, like that of Iranian artist Salim Karami, whose job as a weaver clearly informs his drawings (see page 32, main image). Or fellow Iranian > 20 July 2019 | New Scientist | 31

Views Aperture

SALIM KARAMI, UNTITLED, 2009, INK ON PAPER, 50 × 70 CM, COURTESY OF GALERIE POLYSÉMIE, MARSEILLE, FRANCE

Mahmoud Khan (see below left), who draws mainly trees and animals from his village. The show reflects more than 30 years of growing research and understanding about the kind of intelligence trees possess, and of their importance to the world as climate regulators. “The moment we are destroying most of the forest and planet is the moment we have the real knowledge of plants and trees,” says curator Bruce Albert. He hopes the exhibition will help change how we think about trees, which explains the emphasis on thought-provoking questions and the celebratory tone, rather than doom-laden. “Crying about deforestation won’t change much,” says Albert. Even so, the exhibition doesn’t shy away from the magnitude of humanity’s impact. Take Exit by architects Diller Scofidio + Renfro, which uses visualisations of disappearing forest maps layered with immersive audio of forest birds and falling trees to great effect. And then there are Nilson Pimenta’s felled Brazilian trees, painted to be eerily reminiscent of human bodies. Another gem is a collaboration by botanist Stefano Mancuso and artist Thijs Biersteker in the gallery’s garden. There, sensors track the exposure of two trees – a horse chestnut and Turkey oak – to air pollution and noise pollution, visualising it in real time as pulsing waves and dots on adjacent screens. The contrary relationships we can have with trees is unpacked in Claudine Nougaret and Raymond Depardon’s Mon Arbre, a beautifully shot video of French citizens and “their” trees. One recounts delight at moving to live near a plane tree – only to discover the bark it sheds is a pain. “We discovered they know trees’ Latin names. It makes us realise we all have relationships with trees without being a scientist or botanist,” says Nougaret. ❚

FRANCIS HALLÉ, MOABI, BAILLONELLA TOXISPERMA, SAPOTACEAE (LANGOUÉ, GABON), 2012

MAHMOUD KHAN, UNTITLED, 2019, COURTESY OF THE ARTIST AND GALERIE POLYSÉMIE, MARSEILLE, FRANCE

Salim Karami, Untitled, 2009

Mahmoud Khan, Untitled, 2019 32 | New Scientist | 20 July 2019

Francis Hallé, Moabi, 2012

Adam Vaughan

Views Culture The TV column

Shooting for the moon What was it really like inside NASA’s space programmes? The Smithsonian Channel’s Apollo’s Moon Shot lovingly retells the true stories of the people who created the galaxy’s wildest ride, says Chelsea Whyte

NASA

NASA’s Lunar Landing Research Vehicle on a test flight

“THE Eagle has landed.” Apollo 11 astronaut Neil Armstrong’s words to NASA as the craft landed on the moon 50 years ago became part of the mission’s legend. But few of us remember the response: “Roger, Tranquility, we copy you on the ground. You’ve got a bunch of guys about to turn blue. We’re breathing again.” Even though I know how the story goes, I still hold my breath like those NASA engineers did half a century ago whenever I relive the moon landing on TV or at the movies. It was the moment that the whole world stood still to watch history in action – and its 50th anniversary is creating moon fever everywhere. I have a bad case of it, but then, I always have done. Luckily, there is no shortage of great shows about Apollo to enjoy. Take Apollo’s Moon Shot, a six-parter from the Smithsonian Channel. It covers Project Mercury (1958 to 1963) and Project Gemini (1962 to 1966) in its first two episodes, with the rest focusing on Apollo (1961 to 1972) – understandably, since those teams lived through the highest and

lowest moments of that era of space exploration. The series uses rare archival footage to tell the story of the early days of the US space programme. It also calls on historians from the Smithsonian’s National Air and Space Museum to help explain artefacts from the Mercury, Gemini and Apollo programmes.

“Scouting out a landing spot, the lunar module tumbles out of control. You hear the fear in Eugene Cernan’s voice” The footage is so beautifully restored that, at times, it is hard to believe it is 50 years old. And viewers are given a peek at how NASA’s early astronauts proved they had what it takes. In one scene, a trainee astronaut in a cage is lifted about 15 metres in the air and suddenly dropped to the ground. In another, one of the Mercury astronauts lies back in a chair and is shaken vigorously, as if he is experiencing his own personal earthquake.

Shots from the “Vomit Comet”, the C-131 Samaritan military transport plane used to mimic weightlessness on parabolic flights, are narrated by a reporter who accompanied the astronauts on a training trip. His voice is strained and uncomfortable, but the Mercury astronauts seem to be having the time of their lives – grinning, spinning around in the air and walking upside down on their hands. A few kittens that were taken up for tests looked decidedly less happy. Archival interviews with Alan Shepard, the first American in space, reveal how the astronauts felt and what characters they were. At one point, Shepard describes John F. Kennedy giving him a medal and refers to the president’s much-parodied voice as “his damn Yankee accent”. The show goes behind the glossy, triumphant newsreels to see the real risk of the endeavour. During the Apollo 10 flight, in which Eugene Cernan, John Young and Thomas Stafford scouted out the historic landing spot for Armstrong and Buzz Aldrin, the lunar module starts tumbling out of control. You can see the moon’s surface flash past the window as the module flips, and you hear the fear and frustration in Cernan’s voice as he says: “We’re in trouble”. They regain control of the craft and, with the bravado typical of astronauts, Cernan sums up the experience: “That was wild”. It was – just like the idea to go to the moon, the scramble to build the technology and the pilots who agreed to sit on top of a rocket and hope it blew up in the right direction. Apollo’s Moon Shot captures the wildness of it all.  ❚

Chelsea Whyte is a reporter for New Scientist, based in Boston, Massachusetts. Follow her on Twitter @chelswhyte

TV

Apollo’s Moon Shot Exec. Producer Tim Evans Smithsonian Channel

Chelsea also recommends… Movie

First Man Dir. Damien Chazelle

This brooding biopic reveals the flipside of astroglory: the pressure on Neil Armstrong and his family. It is a full picture of the first person to stand on the moon. Bookazine

The Quest for Space New Scientist Collection

Delve into missions past and present that took humanity to the moon – plus, a tour of the solar system celebrates space exploration.

20 July 2019 | New Scientist | 33

DARREN HOPES

34 | New Scientist | 20 July 2019

Features Cover story

Cosmic countdown Our universe was supposed to last forever. Now a radical metamorphosis looms, reports Anil Ananthaswamy

T

RILLIONS of years from now, long after the sun grows to engulf Earth and then shrinks into a dim remnant of its former self, the universe will enter a quiet retirement. Thanks to its continued expansion, clusters of once-neighbouring galaxies will begin zooming away from each other so fast that even light won’t be able to bridge the gap. Stars will burn out and die. Darkness will fall across the cosmos. At least, that is the most popular scenario. The cold, lonely immortality of this “big freeze” is a direct consequence of the standard model of cosmology, our best description of the universe. It depends on all manner of assumptions, not least that dark energy, the mysterious force thought to be causing the expansion of the cosmos to accelerate, will always have the same unvarying strength. But some cosmologists think that instead of dark energy remaining forever constant, it might diminish over time, causing the universe to collapse in on itself in a big crunch, a reverse of the big bang. Others think dark energy could be growing in potency, heralding a future where the universe could expand so far so fast that the fabric of spacetime starts to tear itself apart. This outcome is called the big rip. Freeze, crunch or rip? Or none of the above? That fourth possibility is the startling conclusion of the latest attempt to divine the fate of the universe. By invoking other mysterious spectres that haunt the cosmos

besides dark energy, it suggests a far weirder turn of events: that the universe may be destined not exactly to end, but to evolve into a state we don’t even currently have the language to describe. Dark energy is the most important discovery in modern cosmology. In the late 1990s, astronomers found that the expansion of our universe, rather than slowing down with age, is  accelerating. Their first instinct was to attribute this to the energy of the vacuum of space-time itself, potentially the result of particles spontaneously appearing and disappearing in otherwise empty space. But when this vacuum energy is calculated using the principles of quantum physics, it turns out to be impossibly large. “The vacuum energy would have accelerated the universe to such large scales that the first stars and galaxies wouldn’t have formed,” says Catherine Heymans, an observational cosmologist at the University of Edinburgh, UK. To avoid this problem, physicists thought that they could dream up quantum processes to cancel each other out, leading to a vacuum energy of zero. In theoretical physics, says Heymans, “it’s relatively easy to set something to zero”. But dark energy, and by extension vacuum energy, turned out not to be zero. Most observations suggest that the vacuum energy for some given volume of space-time in our universe – the dark energy density – is constant over time. This is often called the cosmological constant, and is taken to

represent the strength of dark energy. However, explaining its near zero but positive value proved extremely difficult. These turbulent waters were ideal territory for another attempt to describe the underlying nature of the universe: string theory. Originally conceived as a way of explaining the forces inside atomic nuclei, it soon morphed into a framework for quantum gravity. Theories of quantum gravity seek to gain new insights into the universe by unifying general relativity, which describes gravity and the physics of the very big, and quantum mechanics, which governs the physics of the very small.

Knotty problems By the 1990s, string theory had become one  of the leading contenders for such a theory of everything. Instead of a universe made of fundamental particles, string theory describes one built from unimaginably tiny strings that vibrate in 10 dimensions, nine of space and one of time. To make the theory tally with the three spatial dimensions and one of time that we observe in the universe, the extra spatial dimensions of space have to be “compactified”, curled up so small as to be undetectable. Each method of compactification leads to a different universe. The big challenge was to find the unique solution that describes our particular space-time. This effort ran into a problem. The universe that we appear to live in, with dark energy > 20 July 2019 | New Scientist | 35

represented by a small, positive cosmological constant, is known as a de Sitter space-time. And for all its promise, physicists struggled to use string theory to build such a universe using the simplest ways of compactifying extra dimensions. Then, in 2003, Shamit Kachru, Renata Kallosh, Andrei Linde and Sandip Trivedi (together nicknamed KKLT) came up with a complicated way to construct our sort of space-time from string theory. Their work was hailed as a triumph for the theory, but it came at a huge cost. String theory works at high energies, of the kind that existed moments after the big bang. To describe some particular space-time at today’s lower energies, string theory must be used to find a so-called effective field theory. The exact space-time you get using the KKLT construction depends on precisely how the extra dimensions are compactified and how magnetic and electric fluxes are threaded through these geometries. And by 2005, string theorists showed that this could be done in at least 10500 ways, each giving us a different viable de Sitter space-time. The result was a sprawling landscape of potential universes, a multiverse in which every conceivable spacetime can exist. Although KKLT proposed a way to build an effective field theory that describes a de Sitter space-time, it couldn’t deliver an exact theory for our own.

Enter the Swampland This fact troubled Cumrun Vafa, a string theorist at Harvard University. Not because he found the landscape problematic: “I didn’t have any allergic reaction to that,” he says. Rather, he was unhappy with the KKLT construction itself. Besides not producing the desired result, he says that the KKLT proposal was too mathematically complex to verify: others had to take it on trust that the method worked. Vafa began to look at the question the other way round, asking whether all possible effective field theories can emerge from string

theory, or whether string theory forbids certain varieties, and hence certain types of universes. He realised that, if string theory wanted to remain in contention as a theory of everything, it should outlaw effective field theories that fail to accurately describe our universe once gravity is introduced, a common failing. Such variants should be instantly relegated to a forbidden patch of the string landscape. Vafa christened this patch the Swampland, a slushy bog of untenable ideas. The Swampland idea lay dormant for a decade, says string theorist Eran Palti at the Max Planck Institute for Physics in Munich, Germany. Then, in March 2014, cosmologists using a telescope at the South Pole called BICEP2 unintentionally brought it back into focus. They claimed to have seen evidence of primordial gravitational waves generated by inflation, the exponential expansion of space-time thought to have happened in the first fractions of a second after the big bang. This would have represented the first sighting of ripples in the fabric of space-time, a prediction of Einstein’s general relativity. Cosmologists celebrated. But string theorists were stymied. Their theory couldn’t generate such gravitational waves. In particular, string theory models capable of explaining BICEP2’s gravitational waves had the seeming side effect of stopping inflation prematurely. “Primordial gravitational waves of this magnitude are in strong tension with string theory,” says Palti. In other words, the effective field theories that predict them may reside in the forbidden Swampland. Then, in January 2015, the BICEP2 researchers retracted their claim. The signals they thought were due to gravitational waves were the result of dust in the Milky Way that they hadn’t properly accounted for. The fiasco, however, was good news for some string theorists. It showed that their theory had been right to call such results impossible. Vafa’s Swampland conjecture had passed a big test. “This led to a revival of his idea,” says Palti. Then Vafa proposed something that gave the conjecture yet another shot in the arm.

“We may end up with a new universe that can’t be described in the language of our current universe” 36 | New Scientist | 20 July 2019

“What happened last summer was kind of amazing,” says Andrei Linde of Stanford University in California. After nearly two decades of string theorists failing to construct any simple models of de Sitter space-time, Vafa wondered whether such a thing might actually be impossible. In what he calls the de Sitter conjecture, he and his collaborators boldly speculated that all effective field theories capable of describing a universe where dark energy is a cosmological constant belong to the Swampland. A de Sitter universe can’t be a solution to the equations of string theory. For Linde, the de Sitter conjecture is just that, a conjecture, an unproven explanation. Until it is shown to be correct, he is standing by the KKLT construction and its promise that a universe with a cosmological constant can be described by string theory. “It’s a complicated story,” he says. “One should not, on the basis of arguments which are not proven, suddenly abandon what was done before.” The de Sitter conjecture “may or may not be

more problems than it can solve,” he says. Except the universe may be moving in that direction. Over the past few years, hints have emerged that a changing density of dark energy may actually solve a surprising cosmological conflict. The conflict arises from two different ways of measuring the present-day expansion of the universe, a factor known as the Hubble constant, H0. One method involves measuring it directly by studying stars and supernovae in nearby galaxies. The other involves examining the cosmic microwave background, the universe’s first light that was emitted about 380,000 years after the big bang, and then extrapolating from that data to the presentday universe. The two methods generate significantly different results.

The big twist

correct”, agrees Vafa. “We’ll find out when we study it more.” If proved correct, it has major implications for the standard model of cosmology. Not least among these, according to Vafa and others, is that it suggests a dark energy density that instead of being, to a first approximation, constant, is slowly decreasing with time. If so, that would have profound consequences, says string theorist Timm Wrase at the Vienna University of Technology in Austria: “It certainly has huge implications for the fate of the universe.” Over the coming tens of billions of years, dark energy may go to zero, or even become negative. “And then maybe the universe would end in a big crunch, instead of expanding forever.” Such a form of changing dark energy is called quintessence. The idea was quite popular before the cosmological constant became the flavour du jour. Linde was one of the first to work on models of quintessence, but he is unconvinced. “Quintessence is possible, but it brings

While the discrepancy could be due to experimental error, it could also be resolved by letting dark energy change with time, treating it as a form of quintessence. You might expect string theorists following Vafa’s ideas to be rejoicing at the news. But they aren’t. “The tension in H0 and the de Sitter Swampland conjecture go in opposite directions,” says Wrase. Whereas the de Sitter conjecture requires the dark energy density to get smaller with time, the Hubble constant problem is resolved only if this density increases. As for the fate of the universe, an increasing dark energy density suggests that a big rip, rather than a big crunch, lies in store. “That’s the horror-show version,” says Adam Riess at Johns Hopkins University in Maryland, a leader of one of the teams studying the Hubble constant. Eventually, there would be so much dark energy in each bit of space-time that its repulsive force would shred everything: galaxies, planets, molecules, atoms and, eventually, space-time itself. “Resisting dark energy would be futile,” he says. So we are back to square one, seemingly, with conflicting ideas suggesting dark energy is decreasing, staying constant or increasing with time, and the fate of the universe on the line. And that is where Vafa believes there might be a way of reconciling the Swampland conjecture with the H0 discrepancy. Alongside dark energy, another invisible component of the universe is dark matter, a substance whose gravity is thought to be holding galaxies and clusters of galaxies together. If dark energy is losing strength, says Vafa, this will have an impact on dark matter.

“String theory tells you that there should be an interaction.” He and his colleagues have found that the interaction causes the mass of dark matter particles to decrease over time. And this changes the extrapolated value of the Hubble constant, causing the discrepancy to shrink. “We were not trying to resolve the H0 tension, but it reduced it nevertheless,” he says. “That’s quite a non-trivial thing.” Does this mean we are heading for a big freeze after all, rather than a big crunch or a big rip? Not quite. Look closer, and the consequences of Vafa’s ideas make all other scenarios look tame. It implies that, tens of billions of years from now, the universe will be radically transformed. “What that typically means in string theory is that a new dimension opens up. So it’s a completely new universe, which is not describable in terms of the language of our current universe,” he says. “We now live in three space dimensions. In this new theory, it might be four spatial dimensions, for example.” Any such new spatial dimension would be the result of one of string theory’s extra dimensions suddenly springing free from its  compactification. The universe resulting from this big twist would be nothing like our own. “A completely new phase takes over,” says Vafa. So, while the universe continues to exist, it is unclear what properties it will have and what its subsequent trajectory will be. “More details need to be known to say what may happen,” says Vafa. “We have no way of knowing accurately what this new phase may look like.” A slew of proposed experiments may help resolve the debate, by tightening the bounds on the nature of dark energy. String theorists will be watching closely. After decades of being accused of not making any testable predictions, they could be close to coming up with some, if only in broad brushstrokes. For example, if string theorists can prove the de Sitter conjecture, it would lead to a prediction that the sort of space-time favoured by conventional cosmology can’t possibly exist. But then if experiments find indisputable evidence supporting the cosmological constant and a de Sitter vacuum for our universe, says Palti, “we can say string theory is wrong”. Whatever happens, the universe’s future looks anything but boring. ❚

Anil Ananthaswamy is a New Scientist consultant based in Berkeley, California. Follow him on twitter @anilananth 20 July 2019 | New Scientist | 37

Features

Super fly! B

SHUTTERSTOCK

Meet the edible insect that can also be used to make biofuel, plastics and cosmetics – and could even solve the food waste crisis. David Adam samples its vast potential

38 | New Scientist | 20 July 2019

ZZZZZZZ. Most people would find working next to the noise of thousands of flies a little irritating, and perhaps reach for a rolled-up newspaper. But to Keiran Whitaker, it is the soundtrack of a more sustainable future. That, and the promise of hard cash: Whitaker’s company Entocycle is farming the flies in a specialised lab a short walk from Tower Bridge in central London. Within a year, he wants to be shipping them around the country. As food. These are no ordinary insects. They are bigger than the average housefly but far more sluggish. They don’t eat anything, so they don’t need mouths or digestive systems, which means they can’t bite. They aren’t pests and they can’t carry disease. And as flies go, they don’t even fly that much. When they do, it is like they can’t really be bothered.

It is easy to reach out and just grab one. They are black soldier flies. And if they sound amazing – which they are – then wait until you meet the kids. The larvae of these flies are the next big thing in sustainability. They can be dried and fed to pets. They can replace fishmeal in the diet of farmed fish and animals, and so help protect the oceans from over-exploitation. They can be swapped for the mountain of soya used in animal feed, so saving the rainforests. They can digest all manner of human wastes without generating a lot of greenhouse gases. They can be processed into a kind of plastic. They have been baked into bread and biscuits and mixed into ice cream. They taste, if you were wondering, a bit like peanuts. “These are the most hipster insects in the

world,” says Whitaker, referring to their diet, as he shows me around. As larvae, his flies dine on only the finest leftovers from a local microbrewery and the neighbouring coffee shops. While trains rumble in and out of London Bridge station overhead, the insects are busy in a computer-controlled environment that counts them and works out how much food they need. Which, as it happens, is an awful lot. You might have seen a viral video of a scrum of maggots devouring a pizza – it is quite something. Those are black soldier fly larvae, doing what they do best, eating what we throw away. And they do so in a fascinating, if admittedly grotesque, way by forming a living fountain in which those larvae that have temporarily had their fill are pushed up and away by hungry replacements. Because the adult flies don’t eat, the larvae need to stock up on food before they pupate, an intermediate stage to their final form. That means, after less than two solid weeks of munching, each larva has grown to 2.5 centimetres long and weighs more than 200 milligrams. Almost a third of that is fat and more than 40 per cent is protein. That makes them a valuable commodity. “I think we are going to see insect farming on a massive scale,” says Åsa Berggren of the

Swedish University of Agricultural Sciences in Uppsala. “It has lots of things going for it compared with how we get protein today.” Global demand for protein is soaring and could double by 2050. Yet much of what we produce at the moment we don’t eat, at least not directly. We feed it to farmed animals instead. By weight, about a quarter of all wild fish caught globally are made into fishmeal. For soya – a crop long blamed for driving deforestation in the tropics – some 80 per cent

“These are the most hipster insects in the world” goes to animal feed. Most protein for animal food is sourced from the cheapest providers internationally. That means the farmed salmon you buy in a UK or US supermarket probably ate soya grown in Brazil, while the chickens were raised on ground-up anchovies hoovered from the seas off Peru.

“Food production is the most destructive industry ever invented,” says Whitaker. “And most people have two ways to make change: who you vote for and what you buy.” Pet owners are among the first to have an insect-based choice. In January this year, UK start-up Yora started to mix black soldier fly larvae into its dry dog food. It can do so because regulations on pet food are fairly loose. It is a different story for feeding animals destined for human consumption, especially in places like Europe where the BSE scandal of the 1980s focused attention on what protein animals were eating. Insect protein was caught in the subsequent bans, but those laws are starting to change. In 2017, the European Union said fish farmers could use insect protein, and by 2020 it is expected to allow it in food for chickens and pigs. The US is moving too: late last year, the Food and Drug Administration signalled its approval for the use of insects in chicken feed. There are no restrictions on the use of fat from insects, which is already mixed into pig food made by a company called Protix in the Netherlands – which also supplies black soldier fly protein for Yora dog food. Elaine Fitches, an applied entomologist at Durham University, UK, who wrote a report >

20 July 2019 | New Scientist | 39

ON THE FLY Black soldier flies have a range of uses beyond food.

Plastics Take the protein of the larvae, add glycerol to make it more flexible and you get a substance that can be compressed into sheets of a rigid plastic substitute. A team in Sweden did this by feeding the larvae dog food and human faeces. The material, they suggest, could be used for electrical switch covers or a nice lamp shade. Just don’t get it wet – the result would be a soggy mess. Sewage The fly larvae aren’t fussy eaters. Feed them heavily polluted wastes, including industrial sewage in China loaded with heavy metals including lead, cadmium and mercury, and they barely flinch. Cosmetics Take away the protein and fat from the larvae and what’s left? Chitin, a useful long-chain polysaccharide that has stabilising properties in a range of products. It’s already obtained from other sources such as crab shells and used in your toothpaste, shampoo and expensive anti-ageing cream, but the flies can provide more.

DAVID STOCK FOR NEW SCIENTIST

Biofuel The energy-rich fat from soldier fly maggots can be squeezed out, chemically modified and blended with standard diesel. Tests show that diesel engines can cope with fuel that is 20 per cent fly, which can improve performance and reduce emissions.

on insect protein sources for the EU in 2016, says companies are queuing up to take advantage of the revised laws. “Everywhere you look, there are investments in this area,” she says. “It is now moving from start-up to transition to commercial scale.” US firm EnviroFlight opened a large-scale black soldier fly farm in Kentucky in November. And South Africa-based AgriProtein, which farms maggots reared on food waste, raised $100 million last year to fund expansion. France has already said it wants to be a world leader in the production of protein by 2030, and sees massive insect farms as one way to achieve that. And it isn’t just focusing on the black soldier fly. French firm Ynsect is building a factory in Amiens that it says will rear enough mealworm beetles to produce 20,000 tonnes of larval protein a year, mostly for fish farming. “That is a hell of a lot of little maggots,” Fitches says. Is it all as good as it sounds? Berggren says would-be insect farmers should remember

they are often using non-native species. The black soldier fly, for example, isn’t yet settled in the UK. It is probably too cold for any that escape. Entocycle’s London lab is kept at 30°C. But Berggren says species tend to find a way. “We really don’t know enough to be sure what would happen.” The picture is clearer when it comes to sustainability. Alexander Mathys at the Swiss Federal Institute of Technology in Zurich has just finished a full life-cycle assessment of the environmental impact of Protix’s pilot plant in Dongen, the Netherlands, which grows its black soldier fly larvae on waste from the food industry. By measuring land and water use, energy demand and greenhouse gas production, he found that insect fats and proteins for both animal fodder and human consumption were more sustainable than animal-based sources, and that, while vegetable fodder still scored better overall, insect farming had the edge when it came to water and land use. One way to make insect fat and protein a

“To use flies to turn excrement into food would require quite a shift in our thinking” 40 | New Scientist | 20 July 2019

Keiran Whitaker of Entocycle loves his hipster soldier flies

more sustainable food ingredient is for us to eat more of it directly – instead of feeding it first to fish, chickens and pigs. “I tried to convince the Swiss chocolate industry to replace palm oil with oil made from black soldier fly larvae,” says Mathys. “They didn’t like it.” (One South African company, Gourmet Grubb, has taken the plunge and uses fat from the insects in its ice cream.) Despite the strict rules on what animals in the human food chain eat, there are few controls on using protein from insects in food we eat directly, and insect-based snacks are appearing on supermarket shelves. Food scientists have baked insect flour from black soldier fly larvae, mealworms and even cockroaches into bread. The results, they say, can be dense and a bit chewy – and some give off an unpleasant smell during baking – but taste pretty similar to a regular loaf. Already, a Finnish bakery in Helsinki has started to sell bread made with flour from ground-up crickets. Customers say they don’t notice the difference, although each loaf is about 50 per cent more expensive. Whitaker says Entocycle is aiming beyond animal feed too: “I didn’t start this to feed animals. I started it to feed people.” He is a vegan, but is happy to tuck into a shared plate of his dried whole larvae. It is ethical, he says, because insects don’t have feelings. His business plan is to license farmers to install rows of hundreds of automated trays to fatten

up the larvae, which he would then reclaim, separate into protein and fat, and sell as premium ingredients. Several farmers, keen to diversify their production to stay in business, are already on the waiting list, he says. Just don’t use the M-word. “We don’t like to use the word maggot. We call it a larva. We call it what it is.” It might sound yucky to some, but then most of us – including vegetarians and vegans – unknowingly eat fats and proteins from insects all the time, because the animals are collected when crops are harvested. Under FDA rules, frozen broccoli can include up to 60 whole aphids or mites per 100g and the same amount of chocolate is allowed to contain up to 60 insect fragments. An average can of tinned tomatoes? One fruit fly maggot allowed.

Food for maggots Fitches says the easiest way to make foods processed with insect ingredients more sustainable is to expand what the larvae themselves are allowed to eat. If destined for farm animals, regulations in many developed countries restrict the menu to what is called pre-consumer waste – the byproducts of existing food production – and no meat. That is why Whitaker’s black soldier flies get the brewing and coffee leftovers. There is only so much of that to go around, though, so truly sustainable insect farming on a massive scale

requires finding something else to feed them. Something like that pizza in the video, perhaps. Colossal amounts of food are thrown away every day – which wastes valuable resources and generates the powerful greenhouse gas methane as it rots in compost and landfill sites. By some estimates, if food waste were a country, it would be the world’s third biggest carbon emitter, behind only the US and China. Black soldier flies and other insects have already proved themselves adept at breaking down everything from dead fish (another hit video worthy of your time) and surplus fruit and vegetables from supermarkets, to the mess left behind by Ugandan bootleggers who make a gin-like drink called waragi by distilling ingredients including molasses. And the larvae do so without producing methane – they convert the carbon in the feedstock into the proteins and oils of their wriggly bodies, with some released as carbon dioxide. An assessment by Swiss scientists late last year showed that, when disposing of organic matter, black soldier flies produce greenhouse gas emissions 47 times lower than composting does. Organic matter doesn’t have to mean food waste, though. “To me using manure [to farm insects] is a no-brainer,” says Fitches. “Some people don’t like the idea but we buy farmed mushrooms and they’re covered in manure.” To use flies to turn excrement into fat and protein for our food would require quite a shift in thinking in many societies – and significant changes to regulations. But even if the work of the flies doesn’t ultimately produce food, it could still steer us to a more sustainable future. At one end of the life cycle of what we consume, these insects can help us dispose of what we throw away with less impact on the environment – the Swiss analysis was of a dedicated insect-biowaste treatment plant in Indonesia. At the other, the protein and especially the fat they contain can be put to good use elsewhere (see “On the fly”, page 40). As studies show that insects are disappearing from the natural world, it could be that we realise we need them more than ever. “This is a really exciting time to work in this science as the results are immediately relevant to industry and that’s really cool,” says Mathys. “The topic is really flying.” ]

David Adam is a science writer based in Hertford, UK. His most recent book is The Genius Within (Picador) 20 July 2019 | New Scientist | 41

Features

Last but not least

SALLY ANSCOMBE/GETTY

How much does birth order really affect our lives, asks Helen Thomson, a fun-loving, not-at-all attention-seeking, youngest child

42 | New Scientist | 20 July 2019

M

Y oldest sister is a typical firstborn: responsible, conscientious, the teacher when we played school, the director for our Christmas plays. My middle sister hung out with the cool crowd, always had a lot of friends, was a bit of a wild child. I defy all stereotypes of the attention-seeking, spoiled youngest child and epitomise a sweet, funny, good-natured human. Obviously. For centuries, psychologists, philosophers and pretty much anyone with a family has argued that birth order shapes personality. It goes something like this: firstborns are reliable and hard-working. Middle children are rebellious but friendly. Last-borns are more outgoing and doted on. Only-children are wiser than their years, perfectionists and spoiled. I can almost hear the cries of indignation. If this doesn’t square with what you know about yourself, or in fact most people, you aren’t alone. Despite their popularity,

there has been almost no solid evidence to support these stereotypes. That isn’t for lack of trying. Psychologists have long sought insights into the way birth order shapes us, but recent research has shown the studies to be so flawed that they are almost meaningless. Now, though, the largest birth order analysis yet aims to set the record straight. Meanwhile, there is an urgent reason to turn our attention to birth order: we are starting to appreciate how it may influence physical and mental health – not least because some cells in our bodies harbour our older siblings’ DNA rather than our own. Regardless of the stereotypes, birth order has profound effects. So how much of our personality, success and health can we blame on being an oldest, youngest, middle or only child? It was 19th-century polymath Francis Galton, the youngest of nine siblings, who first suggested that birth order might matter,

Are youngest children really the most attentionseeking?

after discovering that firstborns were overrepresented among English scientists. He theorised that oldest sons get more parental attention and thrive on it. Fifty years later, Austrian psychotherapist Alfred Adler, the second of six children, suggested that older siblings were more privileged, but also “powerhungry conservatives” prone to feelings of excessive responsibility and anxiety. He also suggested that middle children were expert negotiators and considered youngest children to be pampered, irresponsible and lazy, due to being overindulged by their parents. In 1995, Frank Sulloway, now at the University of California, Berkeley, revitalised the debate by proposing his “family niche” theory for birth order effects: this says that siblings’ personalities vary because they each take on a different role within the family dynamic, which reduces competition and facilitates cooperation. For example, in childhood, simply by being older, the firstborn tends to be physically bigger, so might become more aggressive or use their size to their advantage. They are also able to please adults by acting as a surrogate parent to their siblings, which increases their conscientiousness. Later-born children can’t, or have no need to, fill the same niches, so look for alternatives. This may require them to develop greater imagination than older siblings, but makes them more self-conscious as a result. In this way, says Sulloway, birth order isn’t a direct cause of, but a proxy for, the family dynamics that mould your personality. There was only one problem with his proposal: nobody could prove it was right. Over the next two decades, many studies that tried to elucidate exactly which personality traits were driven by birth order found contradictory results. “The literature was a huge mess,” says Julia Rohrer at the University of Leipzig, Germany. “So many of the associations that were found were cherry-picked.” The studies didn’t account for the huge amount of confounding factors, like the fact that an older child is likely to be more conscientious purely because this trait increases with age. On the other hand, later-born children exist only in larger families, and parents who choose to have lots of kids are inherently different to those who have just one. Many studies didn’t account for socioeconomic factors, the age gap between children or how old the parents were when they had them. And when associations were found, they would hold only within very specific circumstances – for older brothers, or for three-child families or for people with

younger sisters exactly two years apart. “Basically if you analyse data in enough ways, you’ll find something,” says Rohrer, “but these are just false positives there by random chance.” To clear up the confusion, in 2015 Rohrer and her colleagues analysed data from 20,000 children across the UK, US and Germany – the biggest data set used up until then. After taking into account all of the confounding factors that had plagued previous studies, they found that birth order had almost no influence on personality whatsoever. The only genuine effect they could find was an association with birth order and intellect – and even that was tiny, equating to a drop in IQ of about 1 to 2.5 points between the oldest and youngest child. That is nothing, says Rohrer. It is about the same difference that you would expect to get if you took an identical IQ test on different days. “It’s interesting that we reliably see this

“Birth order studies have been so flawed that they are almost meaningless” association, but it’s not something that you can detect in everyday life,” she says. This would have been the final nail in the coffin for the birth order effect, had Sulloway not spent the best part of the past two decades trying to take the field one step further. To address the doubts swirling around earlier research, he created three new personality surveys that would allow him to better control for confounding factors. He saw four major issues to address. First, people’s perception of their own personality differs depending on who they think about themselves in relation to. You may see yourself as deferential to your parents, but domineering compared with younger siblings, for instance. So in all three questionnaires, he asked participants to also rate another person, such as a sibling, romantic partner or friend, to help tease these complexities apart. Second and third: people don’t always answer honestly on quizzes, and also tend to acquiesce to questions – so they might say they are both talkative and quiet, for instance, when answering different questions. Research shows that people give more realistic answers if they have previously had to think about moral > 20 July 2019 | New Scientist | 43

conundrums. So Sulloway’s team began one survey with 40 questions about participants’ moral attitudes. They also rated people on acquiescence and accounted for this in the final analysis. Finally, you need a lot of data. “And that’s why it took 18 years to complete,” says Sulloway. This year, after collecting almost 500,000 responses from participants in six English-speaking countries, he was able to analyse the results, which will be submitted for publication later this year. Like Rohrer, Sulloway’s team found a consistent, if small, increase in intelligence in firstborns compared with younger siblings. But unlike her work, his latest analysis suggests that there are real, identifiable effects of birth order on personality. Previous research has confirmed that genetics explain up to 50 per cent of the variation between our personalities. Sulloway and his colleagues found that age and gender contribute 5.5 and 10 per cent, respectively. Birth order, on the other hand, was more modest, accounting for about 4.1 per cent of the variation between personalities. “This is still a pretty impressive effect,” says Sulloway. “Especially where the importance of birth order has long been doubted.” The effect size is smaller than that found by previous, disputed studies, but the new study identified many of the same trends: oldest kids are more likely than their siblings to have an assertive personality and high self-esteem, but also score highly on being moody and tense. Youngest children tend to like making people laugh and are more likely to be extroverts, but can also be self-conscious and get nervous

“The youngest child typically has six months’ less education and earns less than the oldest sibling” easily. Middle children have the most agreeable traits, such as being trusting and cooperative, but are the least likely to be assertive or talkative. An only child tends to be more neurotic, but with relatively high self-esteem. How much stock should we put in these latest findings? Sulloway concedes that siblings can express the same broad traits for different underlying reasons. But he argues that it is important to try to understand what’s going on because birth order carries a lot of psychological weight. “People use birth order to rationalise why they are different from their siblings. They magnify its influence but it’s important to know that some of that influence is real,” he says. Rohrer believes that Sulloway’s family niche theory is elegant, but says even his latest analysis still resembles a study in which you “interact everything with everything and see what sticks”. It may be easier to pin down how birth order affects other areas of life, such as education, career and income. Last year, economist

The siblings within We carry cells from our mother and our older siblings inside us. These might have significant effects on our health

Stem cells

A mother can pass cells on to her children and have fetal cells from her children in her body

44 | New Scientist | 20 July 2019

Stem cell transplants from younger siblings may be more beneficial because their immune systems have already been exposed to older siblings’ cells

Younger siblings have both their mother’s and older siblings’ cells

Sandra Black at the University of Texas, Austin, and her colleagues analysed data on 1.4 million children in Norway and found that as the size of a family increases, the youngest children suffer educationally and economically. In a three-child family, the youngest child typically has about six months’ less education and earns 2.8 per cent less over their lifetime than their oldest sibling. “We don’t know exactly why it occurs, but it might be to do with the first child having more attention and alone time with the parents,” says Black. If that is the case, there may be a way to mitigate against it. In one small study, Douglas Downey at Ohio State University found that Mormon families tend not to see such large birth-order effects, possibly because they have more support from their community. This buffers against any negative effects as resources are diluted with increasing family size. Beyond soaking up more than a fair share of your parents’ attention, older siblings can have an effect on you even before you are born. In 1992, Ray Blanchard at the University of Toronto, Canada, discovered that the more older brothers a boy has, the more likely he is to be gay. “There’s been overwhelming evidence showing the same association since then; I think the finding is pretty much beyond doubt now,” he says. Increasing levels of antibodies in the mother’s immune system may be the answer. Antibodies protect us against foreign molecules, but can also be produced against fetal cells. Last year, Blanchard’s team found that women who are pregnant with boys produce an antibody that targets a protein only found in male fetuses. Mothers who had gay sons with older brothers had the highest level of this antibody, followed by mothers of gay sons without older brothers, then mothers who had heterosexual sons. The protein targeted by these antibodies sits on the surface of brain cells and is involved in how they communicate with one another. It may be possible that these antibodies build up in the mother’s body and at high concentrations have an effect on brain development, influencing sexual orientation. If you assume a causal relationship between having an older brother and being gay, says Blanchard, then the proportion of gay men who can attribute their sexual orientation to their birth order is between 15 and 29 per cent. Birth order may influence our health simply by affecting our exposure to certain hormones or microbes. For instance, some cancers are less common among younger siblings,

THOMAS BARWICK/GETTY

Older siblings can have an effect on you even before you are born

possibly because there are greater oestrogen levels in the umbilical cord in first pregnancies. For firstborns, being exposed to more oestrogen in the uterus could contribute to greater risk of cancer at a later date.

Health risks On the other hand, later-borns are at increased risk of schizophrenia because viral infections associated with the condition are frequently introduced into families by young, snotty toddlers. So a pregnant woman who has young children around is at higher risk of these infections and their adverse effect on her fetus. Our siblings can influence our health in other surprising ways too. Those of us with older brothers and sisters actually have their cells floating around inside us. We now know that fetal cells can circulate in the mother’s blood for decades after they give birth, because the cells travel across the placenta and into the mother during pregnancy. Likewise, a mother’s own cells float into her child. This is called microchimerism. These donor cells act like stem cells, incorporating themselves into every tissue so far studied, including the spleen, liver, heart and brain, where they can stay for the remainder of our lives. Because these cells travel in both directions, we can be colonised by cells originating from older siblings and even from aunts, uncles and

grandmothers. We are all, in other words, human chimeras. The presence of our siblings’ cells may mark the start of the first battle for our parents’ undivided attention. David Haig at Harvard University suggests that these tiny aliens move from fetus to mother to prevent the rapid conception of another child. This would enhance the fitness of the first child, by decreasing competition for maternal care. Fetal cells are found in higher numbers in the lining of the uterus and in breast tissue of recently pregnant women. Haig suggests that the cells may prevent a new conception by boosting lactation and thereby suppressing a woman’s menstrual cycle, as well as by interfering with ovulation and implantation of an embryo. Each fetus modulates the mother’s immune system, and she then passes these modifications onto future children via microchimerism, influencing their immune systems, says Lee Nelson at the Fred Hutchinson Cancer Research Centre in Seattle. The effect can be life-altering. Recently, it was found that people who needed a blood stem cell transplant as a treatment for blood cancer had better survival rates and a reduced rate of relapse if they were a firstborn child who received a transplant from a younger sibling. Simply put, the younger siblings’ immune systems have already encountered the

firstborn’s cells either directly through microchimerism, or indirectly because the older child’s cells have already modified the mother’s immune system, and these changes are passed on in future pregnancies (see “The siblings within”, left). Essentially, the transplanted cells that the older sibling receives are more similar to their own native cells and this confers some benefit. A better understanding of birth order’s influence could even lead to therapies for deadly diseases. The presence of microchimeric cells in blood has been associated with decreased risk for breast cancer, for instance, and increased risk for colon cancer. It may also influence survival in certain kinds of brain tumour. “There are more positive reasons for microchimerism than negative,” says Nelson. She says that if we understood the biological effects of birth order better, we may be able to target inherited cells that cause harm, or improve immune therapies based on observations of the protective effects of birth order. “People haven’t realised how important birth order and the biology associated with it is,” she says, “until now.” ❚

Helen Thomson is a consultant for New Scientist and author of Unthinkable: An extraordinary journey through the world’s strangest brains 20 July 2019 | New Scientist | 45

Recruitment

newscientistjobs.com Recruitment advertising Tel +44 (0)20 7611 1204 Email [email protected]

Bring your career to life Sign up, create your own job alerts and discover the latest opportunities in life sciences at

newscientistjobs.com

Join Gore & Change Gore is a materials science company focused on improving lives through discovery, product innovation and rewarding careers for our Associates. Gore’s pioneering contributions to the science of comfort and protection create fabrics for a range of activities and conditions.

For our plant in Livingston we are looking for a skilled:

Durability Field Testing Engineering / Scientist (f/m/d) - 191462

to be part of a R&D team who are focused on understanding product performance through the combination of in-field and labbased testing. We are seeking someone with a solid technical background, hands-on ability, good troubleshooting/problem solving skills and strong experience in managing projects.

You want to make a difference? Please apply online via:

gore.com/change-life Our Talent Acquisition Team will be pleased to answer your questions on +49 (0)89 4612 2800 or toll free on +800 4612 2800. © 2017 W. L. Gore & Associates GmbH. CROSSTECH, ELIXIR, GORE, GORE-TEX, HELEX, TAG and designs are trademarks of W. L. Gore & Associates.

@science_jobs

46 | New Scientist | 20 July 2019

#sciencejobs

newscientistjobs.com

What’s next? We’re looking for future research leaders in science, technology and engineering to decide.

www.tyndall.ie/researchleaders

48 | New Scientist | 20 July 2019

newscientistjobs.com

Chief Technology Officer – Methane Conversion Market Leader Significant six-figure package

Wilton, Teesside, UK

A key, strategic technology management role with Calysta.

This dynamic, senior level role involves acting as site and global technology lead for Calysta’s Teesside pilot and laboratory facility, as a member of their executive team. Your key accountability will be to achieve strategic objectives through the management of global engineering and technology resources. Responsible for all administration and process innovation, you’ll also secure funding, whilst maintaining strong supplier relations and an excellent Health and Safety record.

Key responsibilities include: • compliance • reporting • high-level networking • driving organisational growth Educated to degree level in engineering, you must have a significant general management track record in engineering and operations within the process (bio-) sector. Your astute strategic acumen complements first-class project management, technology transfer and

influencing skills. Process Development and a proven track record of scaling up industrial/chemical processes is essential. Strong on staff attraction and engagement, with an excellent customer focus, you can manage a multidisciplinary team of scientists and engineers, with a robust results focus. You will provide figurehead presence for interaction with government agencies, business associations and local industry. To find out more about Calysta, visit our website at: calysta.com

To APPLY for this Chief Technology Officer role, you must be an EU citizen or be eligible to work in the UK without sponsorship To apply please email your CV / Covering letter to : [email protected]

Chief Technology Officer Ref: CAL0847

PROJECT MANAGER

DATA SCIENCE, ANALYTICS, SOFTWARE We are looking for Project Managers to join our successful and expanding consultancy. 7HVVHOODSURYLGHVGDWDVFLHQFHDQDO\WLFVDQGVFLHQWL¿FVRIWZDUHVHUYLFHVWRVROYHFRPSOH[ R&D challenges for our clients. Applicants should have a background in science, engineering RUWHFKQRORJ\DQGH[SHULHQFHRIPDQDJLQJDQGGHOLYHULQJVRIWZDUHGHYHORSPHQWSURMHFWV 2XUZRUNUDQJHVIURPVROYLQJUHDOZRUOGFRPSXWDWLRQDOFKDOOHQJHVWKURXJKWRPRGHOOLQJ VLPXODWLRQDQGFRQVXOWDQF\