October 27– November 2, 2018 
New Scientist

  • 0 0 0
  • Like this paper and download? You can publish your own PDF file online for free in a few minutes! Sign Up
File loading please wait...
Citation preview


Atomic tricks for a computing revolution


Regular baths help combat depression


Bit of Grand Canyon found in Tasmania WEEKLY October 27– November 2, 2018


What are memories really for? Why do we forget? Can I trust my memories? Is technology making us forgetful? Is my memory normal? PLUS: Top tips to boost

your memory

No3201 US$6.99 CAN$6.99 4 3



72440 30690



More ideas... more discoveries... and now even more value SAVE 77% AND GET A FREE BOOK WORTH $35

“A beautifully produced book which gives an excellent overview of just what makes us tick”

Subscribe today PRINT + APP + WEB Weekly magazine delivered to your door + full digital access to the app and web Only $3.33 per week (Print or digital only packages also available)


HOW TO BE HUMAN Take a tour around the human body and brain in the ultimate guide to your amazing existence. Find witty essays and beautiful illustrations in this 270 page hard back edition.

To subscribe visit newscientist.com/11380 or call 1-888-822-3242 and quote 11380

Prices are for delivery in the USA and Canada only. International prices apply. Free book How to Be Human is only available with annual App + Web or Print + App + Web subscription purchases where delivery is in the USA or Canada.





Publishing and commercial


Executive chairman Bernard Gray Chief executive Nina Wright Finance director Jenni Prince Chief technology officer Chris Corderoy Marketing director Jo Adams Human resources Shirley Spencer Non-executive director Louise Rogers

Customer services manager Gavin Power HR co-ordinator Serena Robinson Facilities manager Ricci Welch Executive assistant Sarah Gauld Receptionist Alice Catling

Display advertising Tel +1 617 283 3213 Email [email protected] Commercial director Chris Martin Richard Holliman, Justin Viljoen, Henry Vowden, Helen Williams

Volume 240 No 3201

This Week Can new technology beat a chemical attack? 4

Recruitment advertising

On the cover


Tel +1 617 283 3213 Email [email protected] Recruitment sales manager Mike Black Key account manager Viren Vadgama US sales manager Jeanne Shapiro

42 Quantum supremacy Atomic tricks for a computing revolution


The world can ill afford a new arms race. It is time to think seriously about banning cars from cities

Marketing Head of marketing Lucy Dunwell David Hunt, Chloe Thompson

Web development Maria Moreno Garrido, Tom McQuillan, Amardeep Sian

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 Conference producer Natalie Gorohova Marketing executive Sasha Marks

US Newsstand Tel +1 212 237 7987 Distributed by Time/Warner Retail, Sales and Marketing, 260 Cherry Hill Road, Parsippany, NJ 07054

Syndication Tribune Content Agency Tel 1 800 637 4082 Email [email protected]

Subscriptions newscientist.com/subscribe Tel 1 888 822 3242 or +1 636 736 4901 Email [email protected] Post New Scientist, PO Box 3806, Chesterfield MO 63006-9953

14 Soak it away Regular baths help combat depression 7

News 4

THIS WEEK Inside the EU’s nerve agent attack simulation. World’s largest sea bridge. US to pull out of nuclear treaty?


NEWS & TECHNOLOGY Moral machines. Supercomputers made from cell skeletons. Oxygen on Mars. Tasmania’s chunk of Grand Canyon. Seven explanations for mysterious fast radio bursts. WHO calls for ban on virginity testing. Reimagining Super Mario. AI to detect cyberbullies. Honeybees drum at night. Can hot baths help treat mild depression? Gravitational waves could be tractor beams

Quite a trek Bit of Grand Canyon found in Tasmania

31 Special issue: Memory The exquisite illusion that creates our sense of self Plus Car-free cities (22). Fast radio bursts (8). Oxygen on Mars (7). Genes and university (25). Animals in unexpected places (28)

17 IN BRIEF Ugly birds sing better. Largest object ever seen in the universe. Human neurons are special. The mantis shrimp punch

Analysis 22 INSIGHT Why it makes sense for cities to go car-free 24 COMMENT We must live differently to tackle climate change. Overwork in the tech sector 25 ANALYSIS It’s no surprise that genes are linked to university

Features 28 Animals in unexpected places Why predators are straying far from home 31 The memory illusion Our memories make us who we are, but what are they for? 42 Quantum supremacy Michelle Simmons is making the potential of quantum computers a reality

Culture 44 Keep calm and evolve Why Darwin’s tree metaphor still works 45 Craft work Science isn’t just useful, it’s a craft of its own PLUS: this week’s cultural picks 46 The scandal of scholarship Expect righteous anger as a new film reveals an unexpected con

Regulars 26 APERTURE Spirit of the rainforest 52 LETTERS The lab going nowhere at speed 55 MAKE Haunt your own house 56 FEEDBACK City perfume 57 THE LAST WORD Blow out

27 October 2018 | NewScientist | 1

CIVILISATION Discover how our species built a global civilisation, how we gained and lost by doing so, and what might happen next. %X\\RXUFRS\IURPDOOJRRG PDJD]LQHUHWDLOHUV


Editorial Editor Emily Wilson Managing editor Rowan Hooper Art editor Craig Mackie

News News editor Penny Sarchet Editors Jacob Aron, Timothy Revell Reporters (UK) Jessica Hamzelou Michael Le Page, Clare Wilson, Sam Wong (US) Leah Crane, Chelsea Whyte (Aus) Alice Klein


Chief features editor Richard Webb Editors Catherine de Lange, Gilead Amit, Julia Brown, Daniel Cossins, Kate Douglas, Alison George, Joshua Howgego, Tiffany O’Callaghan Feature writer Graham Lawton

Culture and Community Editors Liz Else, Mike Holderness, Simon Ings, Frank Swain

Subeditors Chief subeditor Eleanor Parsons Tom Campbell, Chris Simms, Jon White

End of an agreement The world can ill afford a debilitating new arms race

Design Kathryn Brazier, Joe Hetzel, Dave Johnston, Ryan Wills

Picture desk Chief picture editor Adam Goff Kirstin Kidd, David Stock

Production Alan Blagrove, Anne Marie Conlon, Melanie Green

Contact us newscientist.com/contact General & media enquiries [email protected] US 210 Broadway #201 Cambridge, MA 02139 Tel +1 617 283 3213 UK 25 Bedford Street, London, WC2E 9ES Tel +44 (0)20 7611 1200 AUSTRALIA PO Box 2315, Strawberry Hills, NSW 2012

ON 20 October, Donald Trump announced that the US intends to leave the Intermediate-Range Nuclear Forces Treaty (see page 5). The treaty, signed by Mikhail Gorbachev and Ronald Reagan in 1987, pictured above, destroyed a whole class of smallish groundlaunched nuclear missiles, in many ways the most destabilising and dangerous of the lot. Just as the world requires a massive rechannelling of resources towards reinventing industry, agriculture and energy to combat climate change, a new, expensive arms race looms. The US’s complaints – that Russia has (probably) broken the

treaty by building the things, and that China has a few hundred of them too – may be justified. But the US can easily defend against either threat with similar missiles launched from air or sea. Hopes for a diplomatic resolution are thin. A diminished Russia, seeing in the treaty a symbol of its cold war defeat, is only too glad to see the US get the blame for ripping it up. US National Security advisor John Bolton is fanatically opposed to arms treaties that restrict the freedom of the US to act unilaterally. Results could be far-reaching. If the treaty goes, the remaining

Are cars the new tobacco? © 2018 New Scientist Ltd, England. New Scientist ISSN 0262 4079 is published weekly except for the last week in December by New Scientist Ltd, England. New Scientist (Online) ISSN 2059 5387 New Scientist Limited, 387 Park Avenue South, New York, NY 10016 Periodicals postage paid at New York, NY and other mailing offices Postmaster: Send address changes to New Scientist, PO Box 3806, Chesterfield, MO 63006-9953, USA. Registered at the Post Office as a newspaper and printed in USA by Fry Communications Inc, Mechanicsburg, PA 17055

CARS have become so embedded in our cityscapes that we rarely stop to question whether they need to be there. But as congestion soars and the huge effects of air pollution on our health become clear, it is time to think radically: should we ban cars from our cities? Several places are already moving in this direction. Madrid

will ban most private cars from its centre from November. Oslo has been steadily weeding them out by removing on-street parking and turning roads into pedestrian and cycle paths (see page 22) . Not all cars can go – they are still essential for people with mobility problems, emergency services and in rural areas. But for most people in cities with

big nuclear treaties that limit global proliferation could go too. That would end all international weapons inspections and free other countries, including Saudi Arabia and Iran, to weapon up. And if nuclear weapons, why not chemical and biological weapons, too (see page 4)? On nukes, Trump calls on everyone to “get smart” and not develop these “horrible weapons” in the same breath as pledging $1.4 trillion to developing new ones. His actions seem to stem from the ideology that we will only all be safe when everyone has a gun, writ large. Anything but a smart move. ■

well-connected public transport systems, the unthinkable is thinkable. The collateral benefits are huge: more space for greenery and community events, making it easier to exercise and socialise, and for children to play freely. Just a few years ago, banning smoking in public places for health reasons would have been out of the question. No fundamental liberties will be infringed by starting to think the same way about urban driving. ■ 27 October 2018 | NewScientist | 3


Technology versus nerve agents Could a suite of new tools help contain future Novichok or sarin attacks? Giving a “casualty” a wash in a decontamination tent–

physical similarities with nerve agents on the skin and clothes of casualties. “Anything that would improve the ability to have detection happen at the site would change the way we prepare and add to our resilience significantly,” says Amesh Adalja of the Johns Hopkins Center for Health Security in Maryland, who isn’t involved in the project.


Instant analysis

Sam Wong in Tatoi, Greece

SEVERAL people have collapsed at an airport terminal, showing signs of nerve agent poisoning. Responders in hazmat suits arrive and must urgently determine what chemical people have been exposed to and prevent further casualties. Thankfully, this wasn’t a real attack, but a test of a suite of new tools for responding to chemical, biological, radioactive and nuclear events (CBRN) near Athens in Greece last week. Following the Novichok attack in Salisbury, UK, this year, experts gathered at the Hellenic Air Force Academy in Tatoi to test the latest advances in diagnostic and tracking technology. The field trial is part of the European Commission’s TOXI-Triage project, and it was the first time so many unproven 4 | NewScientist | 27 October 2018

technologies have been tested in a simulated CBRN event. Tools ranged from miniature chemical analysers to social media trackers. The scenario was a simulation of a sarin attack, the nerve agent that killed 12 people in a terrorist attack in Tokyo, Japan, in 1995. The “casualties” – played by 50 Greek air force cadets – held cards describing their symptoms, including loss of sight, inability to walk and convulsions, while a specialist Greek military unit used the tools to try to contain the hypothetical attack. One such device was an ion-mobility spectrometer. This ionises chemicals and assesses how quickly they move in an electric field, enabling the identification of the substances. Ion-mobility spectrometers were Electronic wrist tags make it easier to keep track of each patient

first described in the 19th century, but only now are detectors small and sensitive enough to be held in a hand or embedded into detectors that work like smoke alarms. In the simulation, responders used handheld versions to detect a harmless chemical that shares some

The responders also tested an electronic tagging system for tracking each casualty’s status, location and treatment. This would be very useful, says Ralf Trapp, a chemical and biological weapons consultant in France, who also isn’t involved in the project. “It would free medicalresponse personnel in the field from admin tasks, so they can focus on dealing with victims.” As the simulation continued, the team analysed the breath of the two most severely affected casualties using a tabletop machine. In 40 seconds, the device

For new stories every day, visit newscientist.com/news

“Preparation for chemical attacks has been neglected recently, but the threat may be increasing” from alcohol, date rape drugs or pesticides, for example. The tools worked well on the day, but there were problems. One of the main lessons from the trial is that the tools need to be easier to use when wearing protective equipment. “You’re sweltering hot. You have sweat running down your face. Your gas mask is fogging up – you need better ways of enabling them to use that kind of kit,” says Thomas. The TOXI-Triage team is now analysing the data collected during the exercise to calculate how best to deal with real casualties in such a scenario. Preparation for biological and chemical attacks got a lot of attention after 9/11, but has been neglected recently, says Adalja. “I think the threat is still there and maybe even getting larger.” ■

Scientists call for Brexit cooperation LEADING scientists from across Europe have written to UK and EU leaders, urging them to agree a Brexit deal that preserves scientific cooperation. The letter was signed by 29


can detect the metabolites our bodies produce if we ingest certain substances, including sarin or, in this case, capsules of peppermint oil. It then automatically updates the electronic tag on the tested person’s wrist. Chemical detectors were used to ensure decontamination showers were effective, while an overhead drone used ion-mobility spectrometry to map how far the chemical had spread. A social media tracking tool pulled together relevant posts from tweeting participants. “You’ve got eyes and ears on the ground at extraordinary detail that has never been available to incident commanders before,” says Paul Thomas, lead scientist on TOXI-Triage, and at Loughborough University, UK. All the technologies developed by the project have been designed to have other uses too, otherwise they would seldom be used. The breath-analysis kit could be used in hospitals to detect intoxication

World’s longest sea bridge CHINA’S new mega-bridge was officially opened on 23 October by President Xi Jinping. The 55-kilometre-long structure

The structure is supported by pillars embedded in the sea floor, cables hanging from giant towers, and two artificial islands.

is the longest over-sea bridge in the world and took nine years to build. It crosses the Pearl River estuary to connect the Chinese mainland to Hong Kong and Macau, and is 20 times the length of San Francisco’s Golden Gate Bridge. The bridge becomes an underwater tunnel for a 7-kilometre section so ships can cross and planes can take off from the nearby airport in Hong Kong. About 400,000 tonnes of steel

According to its engineers, it should be able to withstand a magnitude-8 earthquake, a super typhoon or a collision with a 300,000-tonne ship. The project has been criticised for the deaths of 10 workers and feared impacts on local white dolphins. Only 47 of them are still in the area, down from 188 in 2003.

were used in the project, equivalent to eight times the amount used to build the Sydney Harbour Bridge.

US to pull out of nuclear treaty?

China is also home to the world’s longest bridge of any kind, the 164-kilometre-long Danyang– Kunshan Grand Bridge, which crosses land and water between Shanghai and Nanjing.

kilometres. It is one of only two remaining treaties imposing verified limits on US and Russian nuclear forces, which together hold 92 per

PRESIDENT Donald Trump told reporters this week that the US will pull out of the Intermediate-Range Nuclear Forces (INF) Treaty, saying that both Russia and China possess the missiles it bans. While Russia is part of the treaty,

cent of all nukes. Experts fear that if

China isn’t. The latter’s small but growing nuclear armoury consists entirely of intermediate-range missiles, however, and Trump may be trying to force three-way talks. The INF Treaty bans US or Russian

in turn charges that US armed drones

ground-launched nuclear missiles with ranges between 480 and 5500

with inspections, but raised tensions

this treaty goes, the New START treaty, which limits big, long-range nuclear weapons, could go too. Since 2008, the US has charged that a Russian prototype cruise missile violates the INF Treaty. Russia do, as do missile-defence launchers installed in Romania, which could launch medium-range Tomahawk missiles offensively. These issues could be resolved could now make that difficult.

Nobel laureates, including Venki Ramakrishnan, president of the Royal Society, and six winners of the Fields medal, the biggest prize in maths. According to the society, the UK received €8.8 billion out of a total of €107 billion of EU research grants between 2007 and 2013. Many of the largest grants are given to consortia that span countries. “Creating new barriers to such ease of collaboration will inhibit progress, to the detriment of us all,” the letter says. The Francis Crick Institute, a medical research centre in London, revealed this week that 78 per cent of the EU scientists working there said they would be less likely to stay in the UK after Brexit.

Taking the scenic route to Mercury THE BepiColombo spacecraft is on its way to Mercury after a successful launch from French Guiana on 20 October. The joint mission by the European Space Agency and the Japan Aerospace Exploration Agency aims to probe some of Mercury’s mysteries, such as its odd magnetic field, weird pools of ice and hollows unlike anything we have seen on other planets. But before BepiColombo can do that, it has to get to Mercury, a Herculean task because of the sun’s powerful gravity. To avoid flying right past Mercury and falling into the sun, the craft will take the scenic route. It will loop back around Earth once, Venus twice and Mercury six times to get the energy it needs to get into orbit around Mercury. If all goes well, BepiColombo will reach its final destination in December 2025. 27 October 2018 | NewScientist | 5


In a crash, whose life would you spare?

of a preference to spare the young over the old, or to spare those with high status. Decisions to save humans ahead of cats and dogs were less pronounced in a Southern cluster, which included Central and South America, and countries with French influence. The preference there was to spare women and fit people. Many technology researchers and ethicists told New Scientist they thought the results shouldn’t be used to set policy or design

A SELF-DRIVING car is travelling along a two-lane road when its brakes fail. Should it stay in lane and hit a pregnant woman, a doctor and a criminal on a pedestrian crossing, or swerve and hit a barrier, killing the family of four in the vehicle? This derivative of the classic Trolley Problem is the kind of scenario that makes up the Moral Machine experiment, an ethics survey of millions of people from 233 countries and territories around the world. Participants were asked to consider different scenarios in which those who might be saved could be, say, fit or fat, young or old, pets, criminals or those with highstatus jobs. In all, 40 million decisions were collected. Overall, people preferred to spare humans over animals and younger over older people, and tried to save the most lives. The characters that people opted to save least were dogs, followed by criminals and then cats (Nature, DOI: 10.1038/ s41586-018-0637-6). Edmond Awad at the Massachusetts Institute of Technology and his colleagues think these findings can inform

policy-makers and the experts they may rely on as they devise regulations for driverless cars. “This is one way to deliver what the public wants,” he says. The team found that people in regional clusters made similar decisions. In an Eastern cluster, which included Islamic countries and eastern Asian nations that belong to the Confucianist cultural group, there was less

Computers made from cell skeletons

the protein-based scaffolds that give cells their shape.

computers, called logic gates. Adamatzky and his colleagues

Cytoskeletons are constructed from several different elements, including 25-nanometre-wide tubules made from a protein called tubulin and 6-nanometre-wide filaments made from a protein called actin. These structures also distribute information in the form of patterns of atoms, electrons and ions, allowing communication between parts of cells. By forcing these patterns to combine in various ways, it may be possible to perform simple computations. This would essentially reproduce the basic units of digital

have pulled all this together into an overall concept for the first time (arxiv.org/abs/1810.04981).

BUILDING a computer from the skeleton that holds our cells together could allow us to make machines that are smaller and far more energy efficient. To encourage the development of such computers, Andrew Adamatzky at the University of the West of England, UK, and his colleagues have developed a theoretical foundation for computing with cytoskeletons, 6 | NewScientist | 27 October 2018


Driverless cars may soon have to make life-and-death decisions

They argue that cytoskeleton devices would have an advantage over ones made from DNA, another form of biological calculator that some people think could supercharge computing. DNA is good at storage, but poor at processing signals, says

“Cytoskeleton devices could be a more promising way to supercharge computing than those made of DNA”

autonomous vehicles because that would simply perpetuate cultural biases that may not reflect moral decisions. “The fact that there are some cultural patterns should not surprise us, but that has nothing to do with the fact that something is right or wrong,” says ethicist H. Peter Steeves at DePaul University in Chicago. The instinct to save women and children, for example, is rooted in patriarchal views of these groups having less autonomy and therefore being deserving of rescue, he says. We end up having these debates because we anthropomorphise AI, but ethics related to transport isn’t just about self-driving cars, says Joanna Bryson at the University of Bath, UK. We already make decisions and trade-offs about road use that don’t always result in the highest safety for the greatest number of people. “SUVs are twice as likely to kill anybody you hit, and yet we’ve accepted that into our culture,” she says. Programming morality into an algorithm may be impossible, especially if coders and the general public don’t act ethically on the whole, says Steeves. “Then the dream of finding the right moral algorithm is just as absurd as finding the right comedic parabola, or the right colour of dance, or the right frequency for spaghetti.” Chelsea Whyte ■

Adamatzky. Tubulin and actin are also less complex than DNA, making them easier materials to work with. But Ross King at the University of Manchester, UK, who has worked on DNA computers, is sceptical. He thinks it may be difficult to get the signalling mechanisms of cytoskeleton computers to perform digital computation at the atomic level. He agrees with Adamatzky that silicon’s days are numbered, however. We have reached the point where a single supercomputer consumes the same amount of energy as thousands of households, says King. “That’s not scalable.” Douglas Heaven ■

For daily news stories, visit newscientist.com/news

Salty Martian water may hold oxygen for life THE atmosphere of Mars may not contain much oxygen, but that doesn’t necessarily mean the planet itself lacks the stuff. A calculation of how much oxygen could be dissolved in salty Martian groundwater shows that the dusty world may be hiding an abundance of oxygen under its surface – potentially enough to support life. DANIEL VIÑÉ GARCIA/GETTY

We know Mars has oxygen on its surface, which is why it looks red: iron in Martian dust mixes with oxygen to create rust. Vlada Stamenkovic´ at NASA’s Jet Propulsion Laboratory in California and his colleagues calculated how much oxygen could be dissolved in brines just under the planet’s surface. They found that, under particularly cold conditions, certain types of brines could hold just as much oxygen as seawater does on Earth. This would be enough for microbes

western United States,” he says. Beyond extending the Grand Canyon’s reach across the Pacific and into the southern hemisphere, uniting the Tasmanian rocks with those in North America helps to solve an ancient geological jigsaw puzzle. About a billion years ago, all of Earth’s continental plates formed a single supercontinent

Australia’s Grand Canyon connection

and even simple animals like sponges doi.org/cv2v). But we aren’t entirely certain there are liquid brines on Mars. Despite clues, such as recurring slope lineae – dark lines flowing down hills that appear to be liquid – there is no definitive proof on which all researchers can agree. “There have been various different claims for where we may or may not have seen evidence for these brines existing,” says Kirsten Siebach at Rice University in Texas. “Small amounts of brines would be possible, but we aren’t sure that they’re really there.” Even if Mars does have oxygen-rich brine, that’s no guarantee of life, says Robin Wordsworth at Harvard University. “It’s two sides of the coin in a way,” he says. “If you want respiration, oxygen is good, but too much oxidation can be bad for life.” Compounds like hydrogen peroxide can damage cells, which may be

Lucas Joel

THE Grand Canyon in Arizona has a bizarre Antipodean link. A chunk of the rock sequence that has been sliced through to form this natural wonder of the world now sits thousands of kilometres away in Tasmania, Australia. To peer into the Grand Canyon is to behold, in its rock layers, a record of Earth’s distant past. The oldest layers at the bottom date back more than 1.5 billion years. It is some of the most ancient layers in the sequence that interest Jack Mulder, a geologist at Australia’s Monash University. He thinks these rocks – which are between about 1.1 and 1.2 billion years old – look just like similarly ancient rocks in Tasmania. The Tasmanian rocks in question have always seemed a bit out of place, he says. “They

particularly bad for primitive life forms that don’t have that many cells to begin with. Leah Crane ■

These Tasmanian rocks were once part of the Grand Canyon (top)

didn’t look a lot like similarly aged rocks nearby.” Mulder and his colleagues have now found that the rocks contain minerals with the same “geochemical fingerprint” as those in the Grand Canyon (Geology, doi.org/cv24). “We concluded that although it’s now on the opposite side of the planet, Tasmania must have been attached to the

“We concluded that Tasmania must have been attached to the western United States”


to survive (Nature Geoscience,

called Rodinia. But working out exactly how today’s continents would once have fitted together to form Rodinia is no simple task given how long ago it existed. The Tasmanian discovery provides a clue because it is clear evidence that North America and Australia were linked together at the time. “Jack’s paper shows that Tasmania holds the key to tying together the tectonic geography of the time,” says Alan Collins at the University of Adelaide, Australia. “It’s really a good link and tie that allows us to build full plate models of the ancient Earth.” ■ 27 October 2018 | NewScientist | 7


Bid to explain radio bursts from space Chelsea Whyte

STRANGE flashes of radio waves have been a mystery ever since the first one was detected in 2007. It is tough to say what is causing these fast radio bursts (FRBs) because most are here and gone in a moment – only one has ever been seen to repeat – which makes it tricky to gather much data about any of them. But astronomers do have ideas about where they might come from, ranging from the mundane to the exotic, such as alien craft powered by beams of light. A project now aims to gather all the most likely explanations and whittle them down (arxiv.org/abs/1810.05836). “When we started the catalogue at the beginning of the year, we had more theories than we had observations, but we now have more observations,” says Emma Platts at the University


Might colliding neutron stars be the cause of fast radio bursts?–

8 | NewScientist | 27 October 2018

of Cape Town in South Africa. Platts and her colleagues have grouped the explanations in the following seven categories. Smash-ups Mergers between two large astronomical objects could cause radio waves. For instance, when the magnetic field of a superdense neutron star meets that of a white dwarf star – or a supernova ejecting its mass, or even a black hole – the fields might create streams of particles that result in radio waves. The same thing could occur if two neutron stars collided, or a black hole collided with another black hole. Collapses As large celestial objects collapse, radiation can escape in the form of radio waves. An FRB could be a result of a neutron star collapsing into a black hole or a quark star: a hypothetical star at such high pressure and temperature that its subatomic quarks are stripped from the neutrons that make up

its matter. Some ideas suggest that dark matter, the mysterious substance thought to make up 85 per cent of matter in the universe, could be sucked into a neutron star and cause a collapse that would spew out FRBs. Giant bubbles and pulses Rapidly rotating pulsars have been suggested as an FRB source because their magnetic fields could accelerate clumps of particles that can then give off radio waves. Or a pulsar in a cloud of dust could create a wind bubble as it spins, triggering an FRB that travels through the nebula it sits inside. Neutron stars with extremely powerful magnetic fields, known as magnetars, could produce a similar bubble. Active galactic nuclei When an enormous black hole sits at the centre of a galaxy gobbling up gas and dust, some of the matter can gain speed due to the extreme physical conditions and shoot out as a jet before it is swallowed. These jets shine brightly under the forces of heat and friction, shooting out from an active galactic nucleus (AGN). Some ideas about the origins of FRBs suggest that objects or particles may be

interacting with AGNs to produce the characteristic radio waves. Close encounters A pulsar traversing an asteroid belt could strip away charged particles from an asteroid’s surface and produce radio waves characteristic of an FRB. Or a comet captured by a neutron star could break apart and emit radio waves as it is sucked into the star. Axion interactions One candidate for dark matter is a hypothetical subatomic particle called the axion. Groups of these could clump up and collapse or collide with a highly magnetised object such as a black hole or neutron star. The resulting interactions could produce FRBs. Weird stuff Maybe FRBs are created in exploding white holes, mirror opposites to black holes that spew matter instead of sucking it in. Or maybe they come from lightning produced on the surface of a pulsar. String theorists suggest FRBs could occur when the cosmic strings they suppose make up our universe oscillate or collide. “Some of these theories are more likely than others,” says Shriharsh Tendulkar at McGill University in Canada, who works on the project. “That’s why we set up a discussion board, so scientists can discuss the pros and cons of all the theories.” For any of these ideas to be correct, it has to account for several oddities among the 60 or so FRBs found so far. The recorded signals are all high in frequency, suggesting they come from something compact. But they have little else in common. Some FRBs emit polarised light, while others don’t, for instance. What’s more, we have only been able to pin down a few FRBs to their home galaxy, so we aren’t even sure if certain environments produce FRBs more often than others. ■





NEWS & TECHNOLOGY Machines make the next Super Mario YOUR plucky blue box bounds over gaps and hops onto platforms, the pulsating red wall never more than half a screen behind. If it catches you, it is game over. Then the wall falls into a hole, you bounce on it and it is gone. This is Super Mario reimagined by


artificial intelligence. Matthew Guzdial and Mark Riedl at the Georgia Institute of Technology in Atlanta have created a machinelearning system that has taught itself the basics of video game design by watching videos of people playing

WHO calls for end to virginity testing Debora MacKenzie

hymens of women who had or hadn’t had penetrative intercourse were insignificant. Another study found that hymen inspection accurately identified less than 10 per cent of the women who had experienced penetration. Yet in Indonesia, a woman wanting to join the military must have a “virginal” hymen. Virginity tests are also used to humiliate women in prisons, including demonstrators in Egypt’s 2011 Arab Spring. In South Africa, girls who fail virginity tests

DOCTORS, police and employers should be banned from using so-called virginity tests on women and girls, and those who continue to use them should be prosecuted, the World Health Organization has declared. Such tests are used around the world in rape investigations and even in hiring women for certain professions. The WHO is calling on governments to ban these practices, and to educate doctors, police and others that these tests don’t indicate past sexual activity. “Virginity tests are used to humiliate women in prison, For centuries, many people including demonstrators in have believed that the hymen – Egypt’s 2011 Arab Spring” a fringe of tissue inside most vaginas – can be used as a sign of virginity. But there is no may be ostracised, and some evidence that the hymen can employers have held policies of reveal if a woman has had sex, only hiring women who pass. as underscored by a review of Women who fail virginity available research co-authored tests – regardless of whether they by the WHO’s Claudia Garciahave ever had sex – suffer socially Moreno last year. and psychologically, says the In one study, doctors found WHO. Some attempt suicide; that the differences between the others are killed by their families. 10 | NewScientist | 27 October 2018

A demonstration against virginity tests in New Delhi, India, in 2009

classic games, such as Super Mario, Kirby and Mega Man. This allows the AI to learn about the interactions between characters and objects: what happens when this

Virginity tests don’t stop at the hymen. In rape cases in India and neighbouring countries, medical or police examiners insert two fingers into the vagina, to assess the “laxity” of the vaginal muscles, thought to reflect whether a woman has become “habituated” to sex. But vaginal muscle tone reflects no such thing, says the WHO. Nevertheless, in court a diagnosis of past sexual activity can weigh against an unmarried woman who has been raped. Aruna Kashyap of Human Rights Watch says that doctors in India “obsess about vaginal evidence”, even though rape often leaves no vaginal injuries. India’s most recent guidelines on how to treat women who report being raped no longer include the “two-finger test”. But the guidelines have only been adopted in nine of India’s 36 states and territories. “A lot needs to be done,” says Kashyap. While virginity tests are most common in parts of Africa, the Middle East and Asia, the WHO says they also occur in immigrant communities in rich nations, including the UK. ■

thing goes over there, what happens when this thing touches that thing. It then takes the patterns it has identified in individual games and remixes them into new ones. “Some are good, some are bad,” says Guzdial. The above game, nicknamed Death Wall, was one success. Another, called Killer Bounce, has the player jumping across blocks that disappear when you touch them, forcing you to keep bouncing. It was the result of the system taking the Super Mario rule that you dispatch enemies by bouncing on them and then making everything in the game an enemy (arxiv.org/abs/1809.02232). At the moment, Guzdial’s system produces very abstract, blocky games, but he would like to add more recognisable character designs and backdrops. These could also be machine-generated. Guzdial has previously used AI to generate new Pokémon, for example. Eventually, he would like anyone to be able to use such systems. “People often say they want a game that’s a bit like one thing and a bit like another,” says Guzdial. “Wouldn’t it be great if you could show the AI Fortnite and Minecraft and it spat out something new you could play?” Douglas Heaven ■


Cutting-edge Japan: from Tokyo to Okinawa Explore the diverse faces of Japan. Journey from buzzing Tokyo to snow-capped mountains; from hot springs to subtropical coral reefs DEPARTURE:

4 NOVEMBER 2018 TOK YO g HAKONE g K YOTO g OKINAWA 11 d a y s f r o m £ 4 9 9 5 p e r p e r s o n


TECHNOLOGY AND INNOVATION Begin your adventure in futuristic Tokyo. Visit the University of Tokyo and enjoy a talk from a robotics designer on campus. Experience the awe-inspiring Miraikan, Japan’s Museum of Emerging Science and Innovation, before heading for the stunning scenery around Hakone.


OUTSTANDING NATURAL BEAUTY In the shadow of Mount Fuji, visit the volcanic Owakudani valley and walk between steam vents and hot springs. Then catch the bullet train to Kyoto and explore its peaceful temples and lavish gardens where bamboo thickets crowd the skyline.


TAKE PART IN RESEARCH Round off your trip with three days on the subtropical island of Okinawa. Get stuck in at the Okinawa Institute of Science and Technology where you’ll take part in environmental research, learn about sustainable living and how coral is being restored.

SPE A K T O OUR SPE C I A L IS T T E A M AT S T E PPE S T R AV E L T O F IND OU T MORE Visit newscientist.com/travel/Japan or call +44 (0)1285 600 129

Humanity will need the equivalent of 2 Earths to support itself by 2030.

People lying down solve anagrams in 10% less time than people standing up.

About 6 in 100 babies (mostly boys) are born with an extra nipple.

60% of us experience ‘inner speech’ where everyday thoughts take a back-and-forth conversational style. We spend 50% of our lives daydreaming.

AVAILABLE NOW newscientist.com/howtobehuman


For daily news stories, visit newscientist.com/news

Alice Klein

CYBERBULLYING has become a scourge of social media. Artificial intelligence could help: it is learning to detect and filter out bullying posts before they reach users. About one-third of teenagers have been bullied online, according to surveys. Some victims have taken their own lives, prompting governments to introduce harsher penalties for perpetrators. However, these measures fail to prevent exposure to cyberbullying in the first place. Gilles Jacobs at Ghent University in Belgium and his colleagues wondered if they could train a machine-learning algorithm to spot bullying content on social media, which might allow it to be removed before it can inflict damage. They asked linguists to read almost 200,000 posts on the social media platform ASKfm and pick out examples of cyberbullying. Then they trained an algorithm to identify words and phrases in this data that the linguists associated with bullying. When the researchers tested the

Mystery of why old bees drum at night SOMETIMES a honeybee hive isn’t quite buzzing, and the workers need a signal to get busy. Older honeybees use a drumming sound to order their colleagues to get to work. But extensive monitoring of beehives suggests the signal is given most often at night – which is odd given that bees only forage during the day. We have known about this signal,

algorithm on posts from ASKfm it hadn’t seen before, they found it could detect over two-thirds of threats, insults and instances of sexual harassment (PLoS One, doi.org/gfdg6g). The attacks it missed tended to be more subtle and contain fewer obvious slurs, says Jacobs. “It’s really difficult to get 100 per cent detection accuracy because there are so many different ways you can bully someone,” he says. Moreover, the system sometimes failed to distinguish malicious comments from friendly sarcasm, such as “You might want to do some sports ahah x”. Nevertheless, the algorithm should become better at detecting the difference between subtle bullying and harmless jokes as it is exposed to more examples, says Jacobs. Social media sites are already rolling out their own versions of systems like this. Instagram, for instance, announced earlier this month that it had started using a machine-learning algorithm to spot signs of bullying in photos and captions. Once a post is flagged, it is sent to human moderators to review.


AI may protect kids from cyberbullies

AI should make it easier for platforms to moderate vast swathes of content, says Thomas Davidson at Cornell University in New York. “It is simply infeasible to rely on human moderators to manually scan through millions of comments every day,” he says. Instagram hasn’t revealed the accuracy of its automated detection system, but even if it isn’t perfect, it will be backed up by traditional reporting methods,

says Davidson. The platform still lets users manually lodge reports of bullying, which can then be used to refine the algorithm and train it to recognise similar content in the future, he says. Young people will only accept these systems if they do their job without becoming too intrusive, says Jacobs. Surveys of teenagers have found that they support checking posts for cyberbullying, but that “they also want to be able to express themselves freely and not feel like they’re constantly being monitored”, he says. ■

called dorso-ventral abdominal

bees that typically give the signal,

bees that don’t leave the hive and

vibration (DVAV), for about 90 years.

to activate members of the colony.

don’t experience normal circadian

Some biologists have captured

“The recipient bee seems to be

rhythms, so the DVAV signals might

video of bees producing the sound,

energised,” says Bencsik. “She gets

help coordinate their activity with the

but these earlier studies have only

on with her job with more energy,

monitored bees for short periods during the day. Now Martin Bencsik at Nottingham

as if she has had coffee or something.” The researchers’ discovery that the DVAV signal occurs most frequently at

daily cycle of foraging, say the team. The DVAV is one of numerous vibrational signals that bees are

Trent University, UK, and his

night might be related to activities like

waggle dance, which tells other bees

colleagues have analysed a year’s

food processing or brood care. These

where to forage, and the cleaning

worth of data from devices that record

activities are performed by worker

dance, which a bee performs when it

One-third of teenagers have been bullied online–

vibrations in the honeycomb inside three hives, revealing more about the function of the message (Scientific Reports, doi.org/cvx4). Earlier studies suggest it is older

“The signal is given most often at night – which is odd given bees only forage during the day”

known to make. Others include the

wants another bee to groom its wings. Bencsik’s team previously described a whooping sound that appears to be an expression of surprise. Sam Wong ■ 27 October 2018 | NewScientist | 13

NEWS & TECHNOLOGY Gravitational waves could be tractor beams THE ripples in space-time caused by the motions of massive objects could act like sci-fi tractor beams and pull things along.


We already know that a rotating beam of light can trap tiny particles and move them around – this year’s Nobel prize in physics was awarded for related research. This works because particles essentially get stuck between peaks of the light wave as it propagates forward, like a surfer riding a swell. As the rotating wave turns, it acts like

Hot baths could reduce depression Clare Wilson

that there is not enough of a brain-signalling molecule called serotonin, because antidepressants seem to boost levels of this compound. Another suspect is disturbed circadian rhythm, the physical and biochemical changes that happen to our bodies over the day. Your body temperature would normally rise in the morning, peak in the afternoon, then dip back down when you sleep, following a wave-like curve with a difference of about a 1°C between day and night.

LONG soaks in a hot bath could help with depression. A small study has found that afternoon baths just twice a week produce a moderate but persistent lift to mood. The size of the benefit was similar to that seen with physical exercise, which is a recommended therapy for mild or moderate depression. The method could work because raising body temperature in the afternoon helps restore the normal circadian rhythm of temperature, which “Afternoon baths just is often disturbed in people twice a week produce with depression. The baths also a moderate but persistent improved people’s sleep patterns. lift to mood” Depression is one of the most common mental-health issues and is usually treated with But if you have depression, the antidepressants and talking cycle may be flatter, erratic or therapy. However, the medication delayed by a few hours causing may cause side effects, and a the peak to occur later in the day. course of talking therapy can be So Johannes Naumann at expensive, sometimes with long the University of Freiburg in waiting lists in the UK National Germany and his colleagues Health Service, for instance. wondered if a timely hot bath The root cause of depression could nudge the cycle back into is unclear. The dominant view is rhythm and improve mood. 14 | NewScientist | 27 October 2018

His team looked at 45 people with depression, about half of whom were taking antidepressant medicines, which they continued with. People were randomly allocated to either twice-weekly exercise sessions or thermal therapy. The bathing involved going to a spa to soak in a pool at 40°C for up to 30 minutes, then getting out and wrapping up with blankets and hot water bottles for another 20 minutes. After two weeks, some people chose to carry on with the routine at home, while the rest continued with it at the spa. The baths raised body temperature by nearly 2°C. After eight weeks, the hot-bath treatment reduced symptoms by about 6 points on a commonly used depression scale, down from an average starting place of 21, while the exercise programme lowered it by about 3 points. The baths also started working within two weeks, unlike exercise, say the authors in their paper (bioRxiv, doi.org/cvzv). Nick Stafford, a psychiatrist at the Black Country Partnership NHS Foundation Trust, UK, says the approach makes sense given what happens to circadian rhythms in depression. “I’m not surprised they found a benefit, I’m just surprised no one has tried doing this before.” ■

a sort of whirlpool of light, trapping the particle in place. Iwo Bialynicki-Birula at the Polish Academy of Sciences and Szymon Charzynski at the University of Warsaw calculated that the same thing could happen with a rotating beam of space-time ripples, also known as gravitational waves. An object could get stuck in a swell of increased gravity, and rotation of the wave would trap it there. “When something gets trapped, it is like it is in the eye of the gravitational wave hurricane,” says Bialynicki-Birula (arxiv.org/abs/1810.02219v1). Such a gravity vortex would probably be produced when a pair of black holes or other enormous objects orbit one another, he says. All the gravitational waves we have observed came from systems like this, where orbiting black holes or neutron stars spiralled inwards and smashed together. There is just one problem, says Lionel London at Cardiff University, UK. For a tractor beam to do anything, it needs something to grab hold of, but black holes tend to sweep away or suck in surrounding matter. Neutron star systems may host additional matter that could be available to be stuck in a gravitational wave tractor beam, he says, but it isn’t certain the gravitational waves generated by a neutron star would be powerful enough to trap anything. Leah Crane ■

Reach your perfect life science candidate in print, online and on social media. Visit newscientistjobs.com and connect with thousands of life science professionals the easy way DOUGAL WATERS PHOTOGRAPHY LTD/GETTY

Contact us on 617-283-3213 or [email protected]


IN BRIEF Pretty birds just can’t carry a tune

Secret of the mantis shrimp’s mighty punch are revealed THE mantis shrimp packs a mean punch, smashing its victims’ shells with the force of a .22 calibre bullet. Now we know how it does this. It isn’t because it has particularly powerful muscles – instead of big biceps, it has arms that are naturally spring-loaded, allowing it to swing its fist-like clubs at up to 23 metres per second. The key to the shrimp’s punch is a previously identified saddle-shaped structure on the arm just above its club. It works a bit like a bow and arrow, says Ali Miserez at Nanyang Technological University in Singapore. The muscles pull on the saddle to bend it

like a bow, and when it is released, that energy transfers into the club. Miserez and his colleagues found the saddle can hold all that energy without snapping because of its two-layer structure. The top is made of a ceramic material similar to bone and the bottom mostly plastic-like biopolymers. When the saddle is bent, the top layer is compressed and the bottom is stretched. The ceramic can hold a lot of energy when compressed, but is brittle when bent and stretched. The biopolymers are stronger and stretchier, so hold the whole thing together (iScience, doi.org/cvxr). Materials designed using our knowledge of these shrimp shapes may be useful in microrobots, says Ming Dao at the Massachusetts Institute of Technology.

See Letters for more on the power of the shrimp’s punch

The trick that makes our brains superior EACH of our brain cells could work like a mini-computer, according to recordings of electrical activity in the fine branches of the cells. The work has revealed a key difference between human and mouse brain cells, or neurons, that could help explain our superior intelligence. Signals within human neurons have been recorded before, but always in the main “trunk”

of their tree-like structure. Mark Harnett at the Massachusetts Institute of Technology and his team have now used thinner electrodes to record activity in dendrites, fine branches at the end of the trunk. Compared with mice, human dendrites have fewer ion channels: the molecules in the brain cell’s membrane that let electricity flow along the dendrite.

This could give greater computing powers to each cell. In a mouse neuron, if a signal starts down a dendrite, there are so many ion channels that the signal will probably continue into the main trunk of the neuron. In a human neuron, by contrast, the set-up allows patterns of activity in dendrites, and in synapses linked to dendrites, to determine the final “decision” on whether the main branch of a brain cell should fire (Cell, doi.org/cvwp).

A MALE peacock’s call isn’t an appealing noise, but its splendid tail means that doesn’t matter. Now an analysis shows that this is a common trade-off in birds: the best lookers aren’t the greatest singers, while the best vocalists aren’t as easy on the eye. Christopher Cooney at the University of Oxford and his colleagues studied the songs of 518 bird species and their feather colours. In particular, they looked at how feathers differed between males and females of each species – a sign that plumage colour evolved to help attract a mate. They found that birds in which one sex has showier plumage than the other tend to have more monotonous songs. For species in which the males and females more closely resemble each other, the males sing longer songs and use more notes (Proceedings of the Royal Society B, doi.org/cvwk).

A condom that can self-lubricate THE next generation of condoms may lubricate itself with a polymer coating that turns slippery once it comes into contact with body fluids, and that doesn’t dry out. Most condoms are coated with silicone oil. But this, and other lubricants based on water, oil or silicone, are absorbed by the skin, so lubrication wears off. Mark Grinstaff at Boston University and his colleagues have tackled the problem by treating condoms with a “water-loving” coating called HEA/BP/PVP. This turns slippery on meeting water and body fluids and won’t wear off. Grinstaff says the coating has been used to lubricate medical devices, but will need approval for condom use (Royal Society Open Science, doi.org/cvwm). 27 October 2018 | NewScientist | 17


WOMEN’S bodies go through radical changes during pregnancy, and now it is becoming clear that there is also upheaval at the gene level. Alicia Smith at Emory University in Atlanta, Georgia, and her colleagues took blood samples from 63 women early and late in pregnancy to investigate changes in gene expression. Of the 16,000 genes they looked at, 439 altered their activity between the first and third trimester of pregnancy. Many of the changes occurred in genes involved in the immune and circulatory systems. For instance, there was increased expression of alpha-defensin genes, which help to fight disease-causing bacteria, fungi and viruses. This probably protects the fetus from microbes like listeria that can cause miscarriage and pre-term birth, says Smith. There were also changes in genes that protect the fetus from the mother’s immune system. And genes involved in oxygen transport in blood became more active. This is probably because women produce more blood when pregnant to deliver adequate oxygen to the fetus and safeguard against blood loss during delivery (PLoS One, doi.org/cvwg). Smith says knowing how gene


activity changes in the course of healthy pregnancies might allow us to develop tests that can pick up abnormal changes.

18 | NewScientist | 27 October 2018

Fossil life from nearly 4 billion years ago may just be rocks THE oldest fossils in the world might not be anything of the kind, but simply deformed rocks. In 2016, Allen Nutman at the University of Wollongong in Australia and his colleagues said they had found the oldest fossils yet, describing stromatolites – preserved mats of microbes sandwiched between layers of sediment – in 3.7-billion-year-old samples from Greenland. Most rocks that old have at some point been carried deep into the planet, where pressure and heat destroy fossils. But Nutman’s

team found a patch of material that appears to have survived this process relatively unharmed. Now Abigail Allwood at the Jet Propulsion Laboratory in California and her colleagues have reanalysed the rocks in Greenland. They say they aren’t stromatolites (Nature, doi.org/gfdb45). Allwood thought it was odd that the rock face had broken open straight through the middle of all the cone-shaped stromatolites. So she cut 10 centimetres into the rock and found that they are long ridges, with a roughly triangular

cross-section, a structure often seen in deformed rocks, she says. The chemical analysis also doesn’t stand up, says Allwood’s team. Nutman rejects the conclusions. He says that if the objects were produced by deformation, they wouldn’t all have flat bottoms – but they do, and this suggests they are stromatolites. Nutman also criticises Allwood’s team for focusing on one patch of rock, which he says is poorly preserved. However, Allwood points out that the same rocks were the centrepiece of the original paper. ESO/L. CALÇADA & OLGA CUCCIATI ET AL.

Genes change during pregnancy

For new stories every day, visit newscientist.com/news

Nicotine gives mice hyperactive pups EXPOSURE to nicotine has negative effects that echo down the generations – in mice, at least. Male mice exposed to nicotine had offspring with signs of a mouse version of attention deficit hyperactivity disorder (ADHD). To check the impact of paternal nicotine use, Pradeep Bhide at Florida State University and his colleagues put nicotine in water given to 12 male mice and, after 12 weeks, mated them with females never exposed to the chemical. The offspring were between 30 and 50 per cent more active than normal mice. They were also worse at trying to escape from a maze. Moreover, the males, but not the females, spent less time exploring new objects — an indicator of attention deficiency. The brains of the male offspring had levels of dopamine 30 per cent lower than expected and half the dopamine receptors usually present in a mouse brain. Both characteristics are associated with ADHD. No significant changes were found in the brains of female mice (PLoS Biology, doi.org/cvwq). Bhide suspects that nicotine may change gene expression in sperm. Why male offspring are worse affected isn’t known.

Early giant of the universe discovered A SURVEY of the early universe has revealed a huge structure that formed just 2 billion years after the big bang. Its existence could teach us more about how the universe developed and hints at how much dark matter was around then. The half-formed supercluster of galaxies, nicknamed Hyperion after a Titan from Greek mythology, is the largest object seen from that epoch. Hyperion’s mass at just 2 billion years old is 1 million billion times that of the sun. This puts it in the same league as the largest structures in the universe today, but those have

had many more billions of years to grow as gravity pulled them together. Pieces of the supercluster had been seen before, but astronomers hadn’t realised that they were looking at parts of a larger whole. Using the VIMOS instrument on the European Southern Observatory’s Very Large Telescope, which gives a more panoramic view of very distant regions of space, a team led by Olga Cucciati at the National Institute for Astrophysics in Bologna, Italy, were able to join the dots (Astronomy & Astrophysics, doi.org/cvwj).

Where did we come from? How did it all begin?

And where does belly-button fluff come from? Find the answers in our latest book. On sale now. Introduction by Professor Stephen Hawking

Watch 100 fascinating science talks! Watch mind-expanding talks from neurosurgeon Henry Marsh, geneticist David Reich, mathematician Hannah Fry, astronaut Tim Peake and four other inspiring scientists. Over the coming weeks we will be adding more amazing talks, exclusively available to our valued subscribers. Not a subscriber? Visit newscientist.com/12042

Hannah Fry How to be human in the age of the machine

Tim Peake To the ends of the Earth and beyond

Jess Wade Plastic electronics

David Reich The truth about us, and where we come from

Henry Marsh A life in brain surgery

Jim Al-Khalili A brief history of gravity

Tara Shears Why hasn’t the LHC found anything new? (…or has it?)

Subscribe now Save 77% + FREE book worth $35 Visit newscientist.com/12042 or call 1 888 822 3242 and quote 12042


The road reimagined Cities are starting to experiment with banning cars from their streets. It is a move that makes a lot of sense, says Alice Klein IN DOWNTOWN Madrid, the reign of cars is coming to an end. Starting next month, the city centre will be shut off to all cars, barring electric vehicles, those belonging to residents and a few other exceptions. Several other capital cities are also clamping down on cars. Oslo is eliminating on-street parking and converting roads into cycleways and pedestrian paths. Paris and Brussels have started hosting annual car-free days. Others – including Mexico City, Athens and Rome – are planning to ban diesel cars by 2025. So does this herald the end of city driving? There are good reasons for banning cars in dense urban areas. Cars and their supporting infrastructure now fill up to 60 per cent of space in cities, says Mark Nieuwenhuijsen at the Barcelona Institute for Global Health in Spain, which takes a heavy toll on our physical and mental health. “We’ve forgotten that cities are meant to be for people, not cars,” he says.

and diesel cars also produce greenhouse gases – chiefly carbon dioxide – that contribute to climate change. On top of this, road crashes injure 78 million people and kill more than 1 million others globally every year. Long Cyclists in Mexico City take full advantage of a car-free Sunday

The latest estimates suggest that vehicle pollution – which includes nitrogen oxides, soot and carbon monoxide – is responsible for at least 184,000 premature deaths globally each year, mostly due to heart and lung disease. It has also been linked with dementia, with recent research finding that people who live near major highways are 7 per cent more likely to develop the condition. Of course, petrol 22 | NewScientist | 27 October 2018


“Health benefits of going car-free would be 30 times more than from switching to electric vehicles”

commutes by car contribute to physical inactivity, one of the biggest public health problems of the 21st century. Exposure to traffic noise, meanwhile, has been linked with depression in adults and attention problems in children. In other words, cars are bad news. Now, evidence is mounting that bans can help to alleviate some of these problems.

When Paris held its fourth annual car-free day on 16 September, levels of nitrogen dioxide pollution near major roads dropped by as much as 41 per cent and noise levels fell by up to 5 per cent. In Brussels, soot levels decreased by 80 per cent when it banned cars on the same day. And after Stockholm introduced a congestion charge

For daily news stories, visit newscientist.com/news

in 2006, the drop in traffic was accompanied by fewer asthma attacks in children. Unsurprisingly, car bans also seem to reduce road accidents. The city of Pontevedra in Spain, for example, has had zero road deaths in its central zone since it was closed off to all non-essential vehicles in 1999. Additional evidence shows that car restrictions help to promote active lifestyles. In Copenhagen, which has turned many of its streets into car-free walkways and cycleways since the 1960s, over 60 per cent of residents now cycle to work, compared with 2 per cent of people in London. Similarly, more than 80 per cent of children

in Pontevedra now walk to school. For cities that are considering car restrictions, several options are available. One is to ban petrol and diesel cars but permit zero-emission electric vehicles. Another is to ban all cars. A third is to change the way the city is organised so that walking, cycling and public transport are more attractive than driving. Audrey de Nazelle at Imperial College London believes that getting rid of all cars, except for those belonging to less mobile people and essential services, is the winning option. Restricting fossil fuel cars while still allowing electric vehicles doesn’t go far enough, she says. “It will reduce air pollution, but I still think it’s short-sighted and a missed opportunity for more holistic thinking about health,” says de Nazelle. Modelling suggests that the health benefits gained by cities going car-free would be 30 times greater than those from switching to electric vehicles, because it would also reduce accidents and promote more exercise.

Radical change Taking all cars out of the equation would also let us radically reshape city landscapes and make them more people-friendly. The space freed up could be repurposed for other activities, like playgrounds, markets and community events, says de Nazelle. Given that many people would baulk at the thought of banning cars altogether, less extreme approaches may work better. Similar effects can be achieved by simply making other modes of transport more convenient, says Hanna Marcussen, the vice mayor for urban development in Oslo. Since 2015, Oslo has turned many of its roads into walkways and cycleways and removed all on-street parking from its centre to discourage car use. It has also extended its rail network, added

Cars are a very ineicient way to get around – other modes of transport are capable of moving far more people per hour in the same urban space Rail





14,000 9000

Bus Private car



extra trams to existing lines, Yes to Cars in Oslo is filled with made public transport cheaper, complaints about how the city’s and started offering subsidies for “war on cars” is infringing on electric bikes. personal freedoms, making it Few private cars still drive into unpleasant to get around in the city centre, leaving a trickle winter, reducing visitor numbers of taxis, delivery vans and and hurting local businesses. public service vehicles. A recent “Oslo has become a ghost town!” Greenpeace report found that the one post says. city now has some of the cleanest However, Marcussen says it air in Europe. is actually the car-free parts of Large, sprawling cities like Oslo that now attract the most Sydney present additional challenges because they are harder “Our grandchildren will probably look at pictures to traverse on bike or foot, says of our car-clogged cities Dorina Pojani at the University of and think we were crazy” Queensland in Australia. But she still thinks they could go car-free with well-connected public visitors – both locals and tourists. transport systems. And Nieuwenhuijsen disagrees “We need to move away from with the argument that everyone extreme individualism – wanting should have the right to drive. to have our own separate car and “We banned smoking inside detached house – and start buildings because we realised the embracing communal effects of the pollution on other consumption patterns like public people,” he says. “Now we’re transport and apartment-living,” realising the same thing with cars.” she says. Better public transport It is difficult to imagine would also reduce congestion, weaning ourselves off cars which currently traps Sydney because we have become so used motorists in their cars for an to them, says Nieuwenhuijsen. estimated three weeks per year. “We just get in a car and go from But not everyone supports these A to B without thinking about the car-free visions. The Madrid impact,” he says. But de Nazelle Association of Automobile thinks it is only a matter of time Dealers, for example, has raised before other cities follow the lead concerns about the Spanish city’s of Madrid and Oslo. imminent ban on all cars except “Change will happen because for electric models and those we’ll no longer be able to accept belonging to residents, less mobile living in places where we can’t people, delivery drivers and send our children out to play essential services. The group says because of the pollution and the it will discriminate against people danger of cars zooming past,” she who can’t afford electric cars and says. “Our grandchildren will those living further out, while also probably look at pictures of our discouraging visitors to the city. car-clogged cities in 2018 and Similarly, the Facebook page think we were crazy.” ■ 27 October 2018 | NewScientist | 23


An unpalatable truth Shying away from the realities of climate change, such as the need to eat less meat, hinders our ability to tackle it, says Adam Corner IF WE’RE to get climate change under control, the recent Intergovernmental Panel on Climate Change report makes it clear that absolutely everything must be on the table. This includes lifestyle changes such as flying less and cutting down on red meat. Yet Claire Perry, the minister in charge of the UK’s climate change strategy, doesn’t see it this way. She described the idea of government telling us what to eat on climate grounds as “the worst sort of nanny state ever”, adding: “Who would I be to sit there advising people in the country coming home after a hard day of work to not have steak and chips?” Perry’s reluctance to ask us to change also says something important about why public engagement on climate change has not been straightforward. People in wealthy, industrialised

nations such as the UK tend to see climate change as a “psychologically distant” risk: not here, and not now. As a political issue, it struggles to compete with more immediate concerns like insecure employment or immigration. Adding to the public’s sense of disconnect, warnings of apocalyptic futures have been paired with “simple and painless” behavioural changes, like reusing plastic bags and banning straws. The research my colleagues and I do is designed to address these problems. One clear lesson from this research is that it is crucial to talk about climate change in the here and now, linking shifts in the weather to tangible and meaningful actions that people can take to cut carbon. What’s more, most people find it easier to think about their own health than that of the planet, so

In overdrive Overwork shouldn’t be a fact of life in the tech sector, says Michael Cook ROCKSTAR Games, the renowned developer behind the Grand Theft Auto series, has been hard at work promoting its latest digital epic, the cowboy-simulator Red Dead Redemption 2. It is set to be one of the biggest releases of 2018, but it comes at a cost. An interview given by Rockstar co-founder Dan Houser revealed 24 | NewScientist | 27 October 2018

deadlines. In reality, it ruins lives and destroys relationships, and it has been doing so for decades. Given that tech firms hoover up some of the smartest minds on the planet, you would think they could find a better way. My research field, artificial intelligence for games, is exploding right now with just the tools to help. Ceptre, the creation of US researcher Chris Martens, is a mathematical language for automatically checking that game

staff had been working 100-hour weeks to get the game finished. He later clarified that such efforts were a “choice” made by staff. Overwork is treated as a fact of life in the tech sector. Watch a “It seems that when we can film about a plucky tech start-up make things easier, the and you will see people chugging time savings aren’t passed energy drinks and working on to the worker” through the night to meet

code works. Raluca Gaina at Queen Mary University of London is working on AI that can play any game automatically and then report back on its experience. In the 1930s, economist John Maynard Keynes predicted that increasing automation would mean a 15-hour working week by about now. In reality, it seems that when we can make things easier, the resulting time savings aren’t passed on to the worker. If we make it simpler to create the 300,000 animations in Red Dead Redemption 2, say, will Rockstar simply want 600,000 animations for the sequel? If we help designers and developers to

For more opinion articles, visit newscientist.com/opinion

Adam Corner is research director at Climate Outreach, Europe’s leading climate communication organisation

automate the process of making a game, will the companies that employ them simply lay off excess staff until those left are working 100 hours again? Researchers have to be cautious about the kind of work they are doing, and consider whether it is serving workers, or profit projections. As Rockstar Games begins to plan its next epic, we should reflect on what research can do to make sure the future of the creative industries is one that works – not overworks. ■ Michael Cook is a senior research fellow at the MetaMakers Institute at Falmouth University, UK

ANALYSIS Achievement genes


emphasising the health benefits of low-carbon activities like cycling instead of driving, or insulating draughty homes, might be a better way to go. Few of us discuss climate change with friends – perhaps that’s why many politicians underestimate concern on the topic, and the level of support for renewable energy. Getting the conversation going is the first step to meaningful action. Most important of all is connecting with public values across the political spectrum. Avoiding wastefulness in energy use, improving health outcomes, conserving green spaces, creating a sense of pride in rebuilding energy infrastructure, and fostering a sense of responsibility for future generations are all ways of talking about climate change that are more likely to resonate than guilt-laden messages about self-sacrifice. Once the public is engaged in a meaningful conversation about our responsibility to consider how we eat, travel and live in a changing climate, skipping the steak and chips might not sound such a radical proposition. ■

Can genes predict your future university? Clare Wilson

A LARGE study of twins has found links between genes and what university you end up attending, but the relationship isn’t simple. Is there an “Oxbridge gene”? Hardly. A study of 3000 pairs of UK twins has found that, like intelligence, your chance of going to a prestigious university is partly heritable. If your twin gets into the University of Oxford, say, you are more likely to join them if they are your identical twin, with whom you share all your DNA, than if they are your fraternal twin, sharing only half. The work suggests that 57 per cent of the “quality” of your university is down to your genes, says study author Ziada Ayorech of King’s College London (Scientific Reports, doi.org/cvwf). What do they mean by “quality”? The team used university league tables as a measure of quality. Some might argue that this doesn’t account for the possibility that different institutions could suit different people for reasons other than their academic prestige.

Could a genetic test tell you which university your child could get into? Fortunately not. The same team also looked at the DNA of a different 3000 people and could only identify up to 5 per cent of the genes that seemed to be linked to the university attended. That means we are a long way from being able to make genetic predictions about university acceptance. How much of a person’s intelligence is determined by their genes? Previous research suggests between 50 and 80 per cent of the variation in people’s IQ is inherited. As intelligence affects school exam results, which in turn influence university admissions, it is unsurprising that genes may be linked to university destination too. But the team tried to eliminate the effects of intelligence from the analysis by removing the impact of exam results on university entrance, using statistical techniques. When they did this, they found that genes were still behind 47 per cent of the variation in university quality, suggesting they do affect university destination in ways other than by shaping your intelligence.

So is it case closed? Not necessarily. Intelligence genes might influence what university you go to in other ways, for instance by affecting how impressive an application you write and how well you do at interview. Isn’t the whole concept of IQ falling into disrepute anyway? There is a shameful history of using IQ tests to justify racist and sexist attitudes without taking societal inequalities into account. But that doesn’t mean the tests themselves are flawed. Countless studies have found that people with higher IQ on average do better at school, get better jobs and earn more money in life. Whatever it measures, it is something interesting, says Stuart Ritchie, also of King’s College London, who wasn’t involved in the research. Does this mean our fate is determined at birth after all? Not at all. If half the variation in intelligence or university destination is down to genes, the rest must be down to environment. That could include how much encouragement children get, the wealth and education of their parents, and what school they go to. Initiatives like free preschool education can help level the playing field. And, of course, going to any university isn’t the right choice for everyone, including plenty of intelligent people. ■ 27 October 2018 | NewScientist | 25


26 | NewScientist | 27 October 2018

Spirit of the rainforest CONTRARY to appearances, this is a black bear. It is a member of a rare subspecies of the American black bear, called the Kermode bear, which is found only on the coastal islands of British Columbia in western Canada. Around 15 per cent of this subspecies have white fur. Also known as “spirit bears”, these animals are revered by First Nations peoples in the area. White fur is a genetic trait, caused by inheriting a recessive gene from both parents. These bears aren’t albinos – they still have pigmented eyes and noses, which are black. This particular bear’s repast was photographed in the Great Bear Rainforest, a pristine temperate rainforest 600 kilometres to the north-west of Vancouver. This vast area is well supplied with energy-rich salmon that swim upstream from the Pacific Ocean to spawn. Although white fur makes bears more conspicuous, it has its advantages. One study found that spirit bears are 10 per cent more successful at catching fish in the daytime than Kermode bears with black fur, perhaps because salmon can’t make them out against the bright sky overhead. This photo is one of more than 300 included in Animal: Exploring the zoological world, which will be published by Phaidon in October. Yvaine Ye

Photographer Paul Nicklen National Geographic Creative

27 October 2018 | NewScientist | 27

Home from home From sea otters and mountain lions to vultures and alligators, animals are turning up in unexpected places. Isabelle Groc finds out why


HEN Brian Silliman found himself face to face with an alligator, he thought he was seeing a ghost. It was night and he was knee deep in mud in a salt marsh in Georgia, searching for crabs and snails. Alligators are freshwater reptiles, so Silliman was not expecting to come across one, but the pair of red eyes watching him was unmistakably real. Thinking fast, he shook a cage between him and the predator to scare it away. “That freaked me out,” he says. The next morning, haunted by the encounter, Silliman, a conservation biologist at Duke University, North Carolina, couldn’t stop wondering why the alligator was in the salt marsh. Returning to the site, he spotted 28 | NewScientist | 27 October 2018

more of them – and they seemed to be right at home. Diving into the scientific literature, he discovered that alligators are not the only predators found thriving in places where they are not supposed to live. It was a light-bulb moment. “I started re-evaluating everything I had been taught about large animals,” he says. It turns out that at least 23 species of predator have been spotted living in surprising habitats. As well as alligators, the list includes otters, mountain lions, wolves and raptors. But the real revelation is that these creatures are actually returning to places they once occupied. This is giving us astonishing insights into the lives of animals we thought we knew. What’s more, these

predators could be conservationists’ best allies, because they can help improve their old stomping grounds. Sea otters in California were some of the first animals to shake our assumption that predators showing up in unexpected habitats were lost or searching for food. Hunted almost to extinction by fur traders in the 18th and 19th centuries, conservation efforts have seen sea otter numbers increase from about 50 several decades ago to some 3000 now. The recovery was initially limited to coastal areas but, after 1990, otters started turning up in Elkhorn Slough, a major estuary on California’s central coast that is covered in salt marshes and seagrass beds.



“When we first noticed that an ever larger Unsurprisingly, we tend to associate them number of sea otters were living in the slough, with mountains. But historical records show we did not immediately grasp the fact that the that in Patagonia they once lived in open slough could provide all their habitat needs,” grasslands. As sheep farming became says Lilian Carswell from the US Fish and established in South America, they were Wildlife Service. The remnant population of persecuted – along with their prey, a kind of otters had persisted exclusively on California’s llama called a guanaco. As a result, mountain coast, and conservationists had assumed this lions survived only in the remote Andes away is where they belonged, foraging in kelp beds. from humans. But in the past 20 years, sheep But the fact they were thriving in Elkhorn ranching has declined. “We started to see a Slough forced a rethink. “We wiped out these change,” says Mark Elbroch from conservation species from most of their range long before we had ecology as a science,” says Carswell. “If ecologists want to “There is so much we don’t know.” understand the present, The story of California’s sea otters is not they should look at the past” a one-off. Earlier this year, Silliman and his colleagues revealed a wider trend in a paper aptly titled “Are the ghosts of nature’s past society Panthera. “The mountain lions that haunting ecology today?”. As a result of had been removed from the open grassland conservation efforts, a variety of predators are began to come back out of the mountains at reappearing in ecosystems they were pushed the same time as the guanaco was beginning out of by hunting and development. “It is an to move back into the grassland.” exciting time for ecologists,” says Carswell, Such recolonisation is happening in “because these species are coming back to Europe too. Alejandro Martínez-Abraín at the these ecosystems from which they have University of A Coruña, Spain, was puzzled to been absent for many human generations and discover that ground-nesting Audouin’s gulls they are putting their house back in order.” were relocating from archipelagos in the Mountain lions are another example. western Mediterranean to the mainland.

It turns out that sea otters don’t need to live in the sea, nor mountain lions in the mountains

These birds were thought to be small-island specialists, so why were they abandoning their homes? His insight came when he visited Castro de Baroña, an Iron Age settlement on a rugged peninsula in Galicia. “I realised it was a terrible place to live, exposed to winter storms and difficult to cultivate. My conclusion was that the Iron Age people built a village there because they were forced to do so,” he says. Suddenly, Martínez-Abraín saw the connection with the Audouin’s gulls. He realised that human persecution had forced the birds to leave their preferred mainland habitat and eke out a living on the islands. Now, no longer threatened by humans, they are returning to their historical homes – just as the people of Castro de Baroña moved to more hospitable areas once the Roman Empire became peaceful. “We have been studying things from the wrong perspective. If ecologists want to understand the present, they should look at the past,” he says. Martínez-Abraín’s research, published in June, documents a variety of species > 27 October 2018 | NewScientist | 29

“It means there is much more habitat in which endangered species can recover”


returning to their historical habitats in southern Europe as a result of humans moving out of the countryside and decreasing persecution of wildlife. Eagles and vultures have tended to nest on cliffs to avoid humans, but are now increasingly nesting in trees as their forebears did. Likewise, conservation efforts mean that the critically endangered Mediterranean monk seal, which had retreated to caves to avoid human persecution, is returning to beaches. “Everything we see in the present is an artefact, rather than the animals’ true preferences. They are not where they want to be. They are where they can be,” he says.

This may pose challenges for conservationists. For example, the archipelagos where the Audouin’s gulls sought refuge are nature reserves, whereas their mainland homes are not always protected. But it also brings opportunities. “We pigeonholed most of these large predators as being habitat specialists: mountain lions love the mountains, sea otters are kelp bed specialists, alligators love the swamp and fresh water,” says Silliman. “This is a paradigm change. The animals are not habitat specialists, they are habitat generalists and can withstand a much wider range of physical and biological conditions.” It means there is more habitat out there in which endangered species can recover. This provides new hope for species such as the orangutan, whose numbers declined by an estimated 100,000 between 1999 and 2015. Orangutans were traditionally viewed as able to live only in undisturbed forest habitats. However, research reveals that coexisting with humans for tens of thousands of years has left them able to adapt their behaviour to survive in different areas. “Orangutans are ecologically far more flexible than we imagined,” says Erik Meijaard at the University of Queensland, Australia. This realisation presents new conservation opportunities. To take advantage of this, we need to find out what ecosystems animals used to call home. “We don’t know enough about the natural habitat range for most of these top predators,” says Brent Hughes of Sonoma State University in California. Nevertheless, ecologists may find clues outside their field. For example, historical and archaeological records indicate that sea otters used to live in large numbers in estuaries such as San Francisco Bay. What’s more, their move into Elkhorn Slough makes ecological sense because it protects them from 30 | NewScientist | 27 October 2018


Stop the pigeonholing

Alligators are returning to salt marshes and raptors are nesting in trees rather than on cliffs

shark attacks, which are a leading cause of otter death in California. The move back into historical habitats isn’t just good for the predators, though. Hughes has examined the impact of sea otters on the health of Elkhorn Slough. Seagrass meadows are declining worldwide, partly because of pollution. Yet those in the slough have been expanding. “I couldn’t figure out why the seagrass was recovering in Elkhorn Slough and I looked at every possible driver,” he says. Eventually, he discovered that the presence of some 100 otters was a crucial factor. In the highly polluted estuary, excessive nutrients from farm run-off spur the growth of algae on seagrass leaves, which kills the plants. But Hughes documented a remarkable chain reaction leading to seagrass recovery. The otters moving to the slough became the apex predator, eating many crabs. With fewer

crabs to prey on them, grazing invertebrates such as sea hares became larger and more abundant. Sea hares feed on the harmful algae growing on the seagrass, leaving the leaves healthy and clean. “The importance of sea otters to estuaries makes me think about all the efforts that people are spending to restore estuary ecosystems and wetlands,” says Carswell. “It makes me think how important it is to have the full complement of species back in those systems to enact restoration.” In Patagonia, the return of mountain lions to the grasslands is bringing benefits too. Elbroch discovered that they generate far more carrion than do grey wolves – the equivalent top predator – in Yellowstone National Park. “That carrion bolsters the health of ecosystems and creates biodiversity hotspots across the landscape,” he says. As a result, the mountain lions help support the recovery of the threatened Andean condor, which needs carrion to survive. It seems like a win-win. However, Elbroch emphasises the need to educate local people. “If we truly want mountain lions to be successful in this recolonisation of historic habitat, we need a community of people who are willing to live with them,” he says. And that applies wherever predators are returning to past haunts. “We need to think about building tolerance with people because without tolerance there will be no carnivores.” Silliman agrees. He is still haunted by his alligator encounter, but sees it as instructive. “The alligators remind us about the past so we can learn from it for the future when these animals return in larger numbers.” ■ Isabelle Groc is a writer and photographer based in Vancouver, Canada


The grand memory illusion TARA MOORE/GETTY

The truth about your memory is far more elaborate than we thought. Here’s how it really works, and how to make the most of yours

27 October 2018 | NewScientist | 31

HEN considering what makes us who we are, it is easy to think our memories are the answer. Aside from the physical traces of the passing of time on your body, your recollections are perhaps the only thing that links the you sitting here today to the many yous from every previous day of your existence. Without them, your relationships would mean nothing, not to mention your knowledge, tastes, and your many adventures. It might be no exaggeration to say your memories are the essence of you. With this in mind, it is not surprising that much of the burgeoning field of neuroscience has turned its efforts to understanding what makes a memory and how to keep hold of it. Perhaps the most intriguing idea to come from recent discoveries is a reimagining of the dark side of memory – forgetting. As cherished memories fade or when we fail to remember an important task it is easy to feel that memory is failing us. But what the latest findings show is that simply thinking of memory as either accurate or fallible is a mistake. Instead, our memories are malleable, and for good reason. Rather than existing in the filing cabinet of the brain, we conjure memories from scratch with our own style (see page 41). As we sleep, the brain meticulously crafts them into the most useful versions (see page 34). Technology too, affects how we remember and might even create whole new recollections (see page 38). As for forgetting, as infuriating as it can be, we’d be lost without it. Because memory, it turns out, is an illusion – one we create every time we recall the past and that is exquisitely designed to help you live your life.

What is memory for?

32 | NewScientist | 27 October 2018

T FIRST, it seems obvious. Memory is about the past. It is your personal database of things you have experienced. In fact, this repository has a


purpose that goes way beyond merely recalling information. Some of the best evidence of this came from studies of people with brain damage or amnesia. One iconic case was of a patient known as KC in the early 1980s. After a motorcycle accident, he was left with an impaired episodic memory: he could remember facts, but not personal experiences. The weird thing was, it also stopped him doing something else entirely. “By studying patients who have an impaired ability to recall the past, we find that they



are also impaired at imagining the future,” says Eleanor Maguire at University College London. We now know there is a strong link between being able to remember past events and being able to plan for the future. Imaging studies, for example, show that similar patterns of brain activity underlie both. The key seems to be the ability to generate images of scenes in the mind’s eye. “If you think about it, recalling the past, imagining the future, and even spatial navigation, typically involve us constructing scene imagery,” says Maguire. It could be that being able to picture the past enabled us to imagine the future, and therefore plan – one of the complex cognitive feats that stands humans

apart from many other species. If we can’t recall past events and preferences, our ability to make sound decisions crumbles too. This is because during the decision-making process, the brain uses previous choices and existing knowledge to assess options and imagine how they might turn out. The latest thinking is that memory could even have evolved to enable our species to communicate. Earlier this year, cognitive scientists Johannes Mahr and Gergely Csibra at the Central European University in Budapest, Hungary, suggested that the key difference between human memory and that of other animals is that we don’t just recall an event, we also remember how we came to know


Hang, on – you just left the house, but did you lock the door? When it comes to these habitual behaviours, your body knows what to do without the need for conscious thought. The brain no longer encodes the details of a repeated behaviour, so while you remember how to lock the door, there’s no specific memory of when you last did it. This ability to autopilot can be beneficial, freeing up attention for more important things. The danger comes when this “habit memory” takes over when it isn’t supposed to, which can lead to mistakes like forgetting to drop a child off and leaving them in the car instead. Yvaine Ye

about it. “This is different from just knowing about it,” says Mahr. “Having first-hand experience of something gives us authority, makes us more convincing and accurate.” Sending signals that are convincing is a vital part of managing our social relationships and belief systems, he argues. Without this, we would be unable to justify social entitlements and obligations, such as promises, which is often possible only by explicit reference to past events. Whether memory led to complex communication or vice versa is not yet known, but what is clear is that far from being a mere databank of the past, memory is essential for our present and future. Now that’s worth remembering. Alison George

Can I supercharge my memory? UPERHUMAN memory has a special appeal. Who could resist the idea of remembering everything they wanted to, without trying? Learning would be made easy, exams a breeze and you would never forget where you left your keys. Oh and memory-related disorders like Alzheimer’s would have met their match. So it is of little surprise that scientists have turned their attention to ways of enhancing human memory using techniques that stimulate, supplement or even mimic parts of the brain. The immediate goal is to treat memory disorders, but the idea of a memory prosthesis for everyday life is gaining ground. “We’re at the point now where on the one hand it’s very exciting, but on the other it’s controversial because we are not only treating disorders, we’re trying to enhance mental functions,” says Michal Kucewicz at the Mayo Clinic in Minnesota. One approach is deep brain stimulation (DBS), which involves zapping an affected brain area with an implanted electrode. This is already used in the treatment of Parkinson’s disease and epilepsy, among other conditions. Implanting electrodes in brain regions responsible for memory, such as the hippocampus, seems to offer a short-term memory boost too. And small studies have even suggested that DBS might reverse some of the damage seen in certain people with Alzheimer’s disease, halting the shrinking of the hippocampus and potentially encouraging it to grow bigger. DBS is still a blunt tool, however. A moreadvanced approach is to artificially recreate the same electrical activity in the brain that happens when memories form. One such “memory prosthesis” has already been shown to work in people with memory problems resulting from epilepsy. The researchers involved taught an algorithm to learn the pattern of brain activity that occurs when memories go into long-term storage using data they collected from the patients’ brains as they were learning. They then used implanted electrodes to simulate this activity, causing memories to be stored in the brain. The implant boosted memory performance by




30 per cent. A similar technique might even be used to implant memories directly, which could also help those with Alzheimer’s disease. Techniques like these involve invasive surgery, so have been reserved for people with neurological disorders for whom the benefits might outweigh the risks. But many of those behind the research envision a time when any of us could be walking around with implants quietly boosting our brain function. The projects are backed by big names and big money. The US Defense Advanced Research Projects Agency has been supporting the epilepsy memory prosthesis project since

“It’s controversial because as well as treat disorders, we are trying to enhance mental functions” 2013, as part of its Restoring Active Memory programme, which seeks to help improve memory in the injured brain. In 2016, entrepreneur Bryan Johnson invested $100 million in his company Kernel, which seeks to develop brain implants to boost intelligence. The company started by focusing on memory. Since then, Elon Musk has joined the action. The engineer and investor, who heads Tesla and SpaceX, has co-founded a venture called Neuralink. He wants his brain-machine interfaces to merge aspects of human and machine intelligence. One goal is to outsource the hard work of memory-making, whether to combat disease or put an end to worries about where we left the keys. Jessica Hamzelou 27 October 2018 | NewScientist | 33

“During slow-wave sleep, there is this release, a kind of beautiful set of interactions between different brain areas, that is specialised, and it looks different than what we see during awake periods,” says Anna Schapiro, also at Harvard Medical School. There is conversation between regions key to memory, including the hippocampus, where recent memories are stored, and the cortex, where long-term memories end up. This chatter might be allowing the cortex to pull out and save important information from new memories. We don’t need to recall everything that happened in a day, and sleep favours certain types of memory. It homes in on information that might be useful at a later date, and puts it into longer-term storage. Schapiro has found, for example, that merely telling people they will be tested on certain material helps them remember more of it after sleep. Memories with an emotional component also get preferential treatment – especially

What happens to your memories when you sleep?


“Sleep will help to preserve a really intense memory, but decrease the emotionality”

HERE is an old wives’ tale that putting your revision notes under your pillow the night before an exam will make you remember more. That might be stretching the truth, but there could be something in it – you really do learn in your sleep. You don’t need sleep to create a memory. “But sleep plays a critical role in determining what happens to these newly formed memories,” says Bob Stickgold at Harvard Medical School. Sleep determines what goes into long-term storage. It can also select which


34 | NewScientist | 27 October 2018

parts of a memory to retain. And it links new memories with established networks of remembrances. It discovers patterns and rules, says Stickgold, “and it’s doing this every night, all night long.” One of the biggest unanswered questions is how the sleeping brain knows which memories to strengthen, and which to ignore. “We don’t know either the algorithms the brain uses to make these decisions, or how they are implemented,” says Stickgold. What we do know is that sleep is special.

negative emotions. That makes sense from an evolutionary perspective if we are to remember our mistakes and so increase our chances of survival. However, there are also hints that sleep might help to modulate emotional memories. “If you have a memory that was really intense, sleep will help to preserve the memory, but decrease the emotionality,” says Schapiro. This could be crucial for our mental health. “Post traumatic stress disorder might actually be a direct consequence of failures of those sleep-dependent processes that weaken the intensity of emotional responses to memories,” says Stickgold. It could also help explain why getting too little sleep is so bad for you. Negative memories become dominant over neutral and positive ones, for a start. We end up less wise too, says Stickgold. “We remember facts and events, but don’t manage to figure out what they really mean for us and our future.” And what about advice for anyone with exams on the horizon? “It’s much better to go to sleep between studying and taking a test than to stay awake all night studying,” says Schapiro. So put those notes under your pillow and get some shut-eye. Your brain should do the rest. Catherine de Lange


Can you choose what to forget? W

Infants are constantly learning, but only a handful of people have memories from before the age of 2. That’s because parts of the brain critical for longer-term memory are still immature. So babies can form memories – a 6-month-old can recall how to do certain tasks for up to three weeks – but holding onto them is tricky. As the brain begins to mature, that neural machinery gets more efficient and memories start to stick – until the age of 7, when there’s a sudden dip. Children recall far more about earlier events in their lives when asked before they are 7 than just a year later. This sudden erasure, known as “childhood amnesia” may be down to pruning, the brain’s process of snipping away lesser-used connections to strengthen those that remain. Although the slightly older children remember fewer things, their recollections are more detailed. “What’s also developing is your ability to tell a good story,” says Patricia Bauer at Emory University in Atlanta, Georgia. “You place it in context, you tell me what you did, highlight certain events and activity. All of those things are part of what we mean by autobiographical memory.” This points to a possible strategy for hanging onto more of those early memories, or at least attempting to influence which ones stick. In cultures where family storytelling is a cherished pastime, people are more likely to retain early childhood memories. Summoning and reviewing these memories, a process known as reconsolidation, can fortify them. So if you want your child to remember a special trip to the beach, indulge in a little reminiscing, and get them to tell you the story. Tiffany O’Callaghan

E ALL have memories we would rather forget – and it is possible, if you try hard enough.

It is easy to think of memories as something you can actively strengthen, whereas forgetting is a passive process. But we have started to discover it can be intentional too. Perhaps the easiest way to forget something is simply to try to suppress a memory. Jeremy Manning at Dartmouth College, New Hampshire, has found that just telling people to “push thoughts out of their head” is enough to make them forget lists of words they have learned to associate with particular cues. “We don’t know how, but people seem to know how to do it.” This seems especially paradoxical because we also know that rehearsing memories helps to strengthen them. Suppression has been linked to decreased activity in the hippocampus, so we may be unknowingly reducing our hippocampal activity by focusing on the present, says Justin Hulbert at Bard College, New York. This won’t work for everyone. Posttraumatic stress disorder (PTSD) involves intrusive memories that keep coming back – often suddenly and unexpectedly. Studies have found that people with this condition are less able to suppress memories, even those unrelated to traumatic incidents. But other approaches for forgetting



Given the vital role of sleep in memory formation (see “What happens to your memories when you sleep?”, page 34), this is also a prime time to intercept them. Earlier this year, Katharine Simon at the University of Arizona and her colleagues found that they could train people to associate a particular sound with the instruction to forget something. They then taught the volunteers to associate other sounds with specific words. Then, as the volunteers slept, the team reactivated the memories of some of these words using their associated sounds, while also playing the “forget” sound. A week later, the volunteers were worse at remembering these words than words that hadn’t been targeted.

might help, including what are known as cognitive vaccines: interventions that can “inoculate” the brain against the onset of PTSD symptoms if administered soon after trauma. Some computer games seem to do the trick. Playing Tetris after watching an

Being able to exert some control over what you remember probably helps to bolster your resilience in the face of adversity, says Hulbert. Beware the downsides, however. Hulbert’s team found that when you try to suppress a memory, you are later less likely to remember things that happened around the time you attempted suppression. It seems that quietening your hippocampus to block a memory causes an “amnesic shadow” that more generally impairs memory formation.

upsetting film has been found to reduce flashbacks of that film, possibly because thinking about a visual task stopped the brain from processing the visual images of death and injury from the film. However, doing a non-visual task, such as playing a general knowledge game, actually increases flashbacks.

And good can come from holding on to even the most awkward of memories, Hulbert says. “For sure, bringing one to mind can be cringe-inducing, but it’s important to reflect on the good that certain embarrassing memories can bring, as learning experiences that teach us what not to do again.” Penny Sarchet 27 October 2018 | NewScientist | 35


Get active Exercising after learning will help facts stick. For best results, wait several hours before working out.

Can I trust my memories? Psychologist Elizabeth Loftus exposed false memories in historic sex abuse cases. Now there are fresh reasons not to believe your own memories, she tells Clare Wilson

Quiz yourself When it comes to revision, reviewing the material isn’t enough. You need to test yourself repeatedly too.

Take a break You’ll remember more if you take regular breathers from learning. For best results, do something totally different and absorbing.

Timing matters Teenagers remember better if they learn in the afternoon or evening, while older adults tend to have morning brains.

Try interval training There’s a “sweet spot” for when you should revise. Revisit material at a point 10 or 20 per cent of the way between the time of learning and of taking a test to improve your memory by at least 10 per cent.

Sleep on it Snoozing shortly after learning new facts or skills helps the brain reinforce its memory traces – especially if you have a test the next day.

Chew gum It can help with recall during a test. However, the effects are short-lived, so save your chewing for when you need it most. Kate Douglas 36 | NewScientist | 27 October 2018

O ONE has done more than Elizabeth Loftus to expose the fallibility of human memory. In the 1990s, amid growing panic over claims of satanic child sex abuse rings, the psychologist showed how easy it is for people to develop false memories of events that never happened. All it took was repeatedly being asked to imagine them. At the time, this was a common psychotherapy technique to recover supposedly repressed memories. Over the past three decades, Loftus, from the University of California, Irvine, has become well known for her work as an expert witness in legal cases. Her ongoing research on the fallibility of eyewitness testimony has taken on fresh importance in an era of fake news, the Me Too movement and digital image manipulation.


Why did you first start looking into false memories?

I had already been looking at how reliable eyewitness testimony was, to see if people’s memories of the details of an event could be distorted. Like if the guy running away had curly hair, not straight hair. But in t he 1990s, when there was an explosion of highly improbable satanic child abuse claims, it looked like people were developing whole memories for things that didn’t happen. We came up with the idea of trying to make people remember an event that never happened – being lost in a shopping mall when they were young. How did you do it?

We told people we were doing studies of childhood memory, and we talked to their parents to get some stories. Then we would interview adults and present them with three

true events from their childhood, and a completely made-up experience about how they got lost in a shopping mall, frightened, crying, and were ultimately rescued by an elderly person and reunited with the family. After they’d had about three interviews, we found that about a quarter of these adults fell prey to the suggestion and developed a partial or complete memory of being lost. Why was that discovery important?

At the time, people were going into therapy with depression or an eating disorder and coming out with an even bigger problem, namely memories of traumatic experiences that they thought they had repressed. Their therapists weren’t deliberately planting false memories. They believed that child abuse was the most likely explanation for their client’s problems, and they needed to recover the memory to get better. Innocent people were getting accused and families were being destroyed. What was the reaction?

I started getting hate mail and death threats. There was a letter-writing campaign to try to get me fired from my university position. I also got sued for exposing an egregious case of wrongful accusation. I spent many years fighting off that litigation. These days things have calmed down quite a bit but there’s still some hostility. The Me Too movement has led to a surge in historic claims of sexual assaults. Do you think some of these could be based on false memories?

It is possible. We have to accept that when there are two people whose versions of an

it at 60. People often don’t detect you gave them the wrong rating and they start to feel less anxious about the task. When they look back, it was less awful for them. You could do this with kids when they go to the dentist. A former student of mine did some research with kids at a dental clinic, and she got them to remember less fear and pain, and they also behaved better at the next visit. So there could be benefits to fallible memories?

If your kid has had a traumatic but minor experience,ratherthandwellingonthenegatives, it might be better instead to talk them up. To say:

“People remember voting in elections they didn’t vote in. It makes them feel better”


“You were so brave, you hardly cried.” It is generally a little easier to plant a positive memory than a negative one. We don’t know why, it just empirically seems to be the case.

event are different, the man’s version may not be the truth or, alternatively, maybe the woman’s version is not the truth. We have to look for other sources of evidence to corroborate either person. But right now, at the height of “Me Too”, people are not as interested in hearing you talk about false accusations as they might have been a year ago. The pendulum has swung too far in the direction of automatically believing the accuser. It used to be too far the other way. But we know most abuse cases are not successfully brought to trial...

I absolutely see what you’re saying. But as an expert witness on memory, I see a different subset of cases to the ones that most people see. I see the most contentious ones. I hate the idea that people will try to point to all the false memory work and use it to deny guilt when they’re truly guilty. I think that probably sometimes happens and it’s just going to be a cost. I don’t know what we can do to stop that.

What other memory problems has your research shed light on?

We have been doing some work on a phenomenon called memory blindness. Say that someone is being interviewed after witnessing a crime. They tell you that person was wearing a green jacket. Later on you tell them they told you the jacket was brown. We are exploring the extent to which people even notice you fed back a different answer from the one they actually gave. Often they don’t. We think this can be a problem in cases where the police are writing out a statement. They say “Here’s what you told me.” What if there are errors contained in it? It can happen. We are showing that people can fail to detect them and be influenced by them. Can we misremember our feelings as well as facts?

The evidence would suggest so. Another study we are doing is we take you through a difficult task and ask you to rate your anxiety. I tell you that you rated it at 40 when really you rated

Is there any evolutionary reason why memory is so unreliable?

One benefit is that when errors creep in, you can fix them and update memories with true information. Another is that some errors can make you feel better about yourself. These are called prestige-enhancing memory distortions. A common example is people remember voting in elections they didn’t vote in, because they like to think of themselves as civic-minded. Sometimes it gets people into trouble, like in “stolen valour cases”, when someone famous says they were a brave soldier on the battlefield and it turns out they were really behind a desk on that day. So most of the time it is a harmless delusion?

If these kinds of prestige-enhancing distortions aren’t caught, it does allow people to feel better about themselves. People with depression don’t have them as much as everyone else. Such people are sadder but wiser. This is just a correlation, so we don’t know if the lack of prestige-enhancing memory distortions is causing the depression. But it does suggest another possible upside to the unreliability of our memories. If there are costs, there have got to be some benefits. ■ Clare Wilson is medical news reporter at New Scientist 27 October 2018 | NewScientist | 37

Is technology making my memory worse? S AN ostrich’s eye bigger than its brain? This kind of trivia question was once a cognitive workout, but when was the last time you really pondered a question, rather than simply turning to the internet for help? Then there are phone numbers and friends’ birthdays: information we once stored in our brain is now held in the smartphone in the palm of our hand. Outsourcing memories, for instance to pad and paper, is nothing new, but it has become easier than ever to do so using external devices, leading some to wonder whether our memories are suffering as a result. Probably the largest data dump is of snapshots of events, whether it is thousands of photos posted on social media or status updates documenting our lives. You might think that taking pictures and sharing stories helps you to preserve memories of events, but the opposite is true. When Diana Tamir at Princeton University and her colleagues sent people out on tours, those encouraged to take pictures actually had



Is my memory normal? Why do some people remember what they did years ago, whereas others have no clue, but never forget a face or are masters of the trivia quiz?

38 | NewScientist | 27 October 2018

I know that I went out for dinner last month, but I can’t remember anything about the experience How much we remember of events we have experienced seems to fall on a spectrum. At one extreme, some individuals are unable to form these kinds of memories at all. “People with severely deficient autobiographical memory syndrome would report an awareness of the fact they were at the dinner, but they don’t have a feeling of re-experiencing it. It’s more of a factual memory,” says neuropsychologist Brian Levine of the Rotman Research Institute in Toronto. At the opposite end of the spectrum are those with “higher superior autobiographical memories”, who can

recall in precise detail events from decades ago. The best-known case is that of a woman called Jill Price, who can recall most days of her life from the age of 11. The majority of us fall somewhere in between. Strong autobiographical memory skills are linked to the ability to form vivid visual memories of experiences, and probably to a strong sense of your own self-awareness.

Random memories pop spontaneously into my mind all the time Known as “mind pops”, these involuntary recalls happen to all of us, on average about 20 times a day, although there is a lot of variation between individuals. “It’s a basic

“Creating a hard copy of memories in media leaves a diminished copy in our own heads”

a poorer memory of the tour at a later date. “Creating a hard copy of an experience through media leaves only a diminished copy in our own heads,” she says. People who rely on a satellite navigation system to get around are also worse at working out where they have been than those who use maps. The mere expectation of information being at our fingertips seems to have an effect. When we think something can be accessed later, regardless of whether we will be tested on it, we have lower rates of recall of the information itself and enhanced recall instead for where to access it. “These kinds of studies suggest that technology is changing our memories,” says Sam Gilbert at University College London. “We increasingly don’t need to remember content, but instead, where to find it.” In some instances, this could be useful. When people were given two lists of words and asked to memorise them each in 20 seconds, those who were allowed to save the first list on a computer rather than deleting it before moving on to the next, could remember more information from the second list at a later date. It seemed as if cognitive offloading freed up vital brain resources that allowed them to better memorise new information. But relying too heavily on devices can mess with our appreciation of how good our memory actually is. We are constantly making judgements about whether something is worth storing in mind. Will I remember this

characteristic of autobiographical memory,” says Dorthe Berntsen of Aarhus University in Denmark, who studies this phenomenon. Once they pop into your head, they soon disappear. “They’re like dreams – if you don’t write them down, you forget all about them,” Berntsen says. We tend to experience more of these spontaneous memories as we age and retrieve fewer memories consciously, perhaps because we find it harder to inhibit thoughts as we get older. Berntsen’s work shows that they tend not to spring up when we are focused on a task, but are more likely to appear in dull moments. She thinks that, far from being an unwanted distraction, they are an important component of daily functioning.

tomorrow? Does it need to be written down? Should I set a reminder? This is called metamemory, and technology seems to screw it up. For instance, people who can access the internet to help them answer general knowledge questions, such as “How does a zip work?”, overestimate how much information they think they have remembered, as well as their knowledge of unrelated topics after the test, compared with people who answered the questions without going online. You lose touch with what came from you and what came from the machine. “These are subtle biases that may not matter too much if you continue to have access to external resources,” says Gilbert. “But if those resources disappear – in an exam, inan emergency, in a technological catastrophe – we may underestimate how much we would struggle without them. Having accurate insight into how good your memory actually is, is just as important as having a good memory in the first place.” For now, technology seems to be tweaking rather than upending our capacity for memory, but if the interface between us and devices merges more in the future, “the brain will really begin to adapt in ways we can’t anticipate right now”, says Martin Conway, director of the Centre for Memory and Law at City, University of London (see “Can I supercharge my memory?”, page 33). So if you are ever again asked about an ostrich brain, try the encyclopaedia in your head before reaching for your phone. Just remember, the answer is yes. Helen Thomson

These involuntary memories are often associated with the environment we are in, and there is a high probability they have relevance to the ongoing situation, she says. “They can give you an update, reminding you that last time you were in this situation you did this or that,” she says. But they are also cheap. “They don’t require the parts of the brain that require effort – executive functioning. If they are not relevant, you don’t have to think about them,” Berntsen says.

I can remember facts, but am rubbish at faces You might come across as rude if you don’t remember people, but don’t beat yourself up about it, everybody’s

memory is different. This could be down to innate differences in brain wiring. People with prosopagnosia, or face blindness, for example, can’t easily tell faces apart, even if they belong to people they know well. At the other end of the spectrum are super-recognisers, who have an amazing memory for faces. For the rest of us, our memory skills (or lack thereof) are more likely to be due to our life experiences and strategies we’ve picked up along the way. Most of us start out with roughly the same memory ability, but “subtle differences at the beginning get amplified by experiences and interests that build on each other. It’s not intrinsic, it’s acquired,” says neurologist Barry Gordon at Johns Hopkins University


Emotion and memory go hand in hand. We secrete stress hormones, such as cortisol and adrenaline, when we are emotionally aroused, whether the result of a trauma or a fantastic concert. These hormones trigger the firing of signals in the brain, which promotes memory formation. The flip side is that when it comes to retrieving memories, stress can hamper our efforts. It can also prevent us from updating existing memories with new information. Which explains why, despite our best efforts, it is all too easy for the mind to go blank in the stressful setting of a presentation or the exam hall. YY

in Baltimore, Maryland. Expertise, prior knowledge and practice make a big difference to what we remember. Tests of chess masters, for example, show that they have a superior memory for patterns of pieces on a chessboard, but only for ones that are plausibly found in the game. Their ability to remember random positions is little better than that of novices. And studies on master memorisers who, for instance, can remember thousands of digits of the number pi, show that their superior powers of recall are due to strategies to “chunk” information into meaningful groups, not any innate talent for remembering. “They still need sticky notes on the fridge door to remember their shopping list,” says Gordon. Alison George 27 October 2018 | NewScientist | 39

What happens to memories over time? M

EMORIES fade quickly, as we all know too well. “All things being equal, it’s harder to remember things from a

long time ago compared to more recent events,” says neuroscientist Marc Howard of Boston University. But forgetting doesn’t just happen by accident. Evidence suggests that it is largely down to active processes in the brain. In the hippocampus, for instance, which plays an important role in memory, new cells are formed throughout life. It takes energy to do this, yet these cells seem to overwrite established memories and induce forgetting. Why should the brain invest energy in dismantling its own memories? The issue isn’t storage space: given the number of cells and connections in the brain, there is reason to think we could remember much more than we do. According to Blake Richards at the University of Toronto, Canada, the goal of memory isn’t to store information indefinitely, but to optimise decisionmaking in the future (see “What is memory for?”, page 32). And it seems that forgetting most of our experiences actually helps us learn important lessons. Each memory is thought to be stored in


an interconnected network of brain cells. To retrieve a memory, you need some part of its content: for example, to recall who came to your last birthday party, you might start by picturing where the party took place. Artificial intelligence researchers have built computer programs that work on the same principles, known as neural networks. They have found that when memories are distributed across interconnected units like this, there is a lot of potential for what’s called interference, in which one memory effectively impedes the recall of another. This is especially true if they share some of the same content, so you might end up confusing memories of two birthday parties that happened at the same venue. In addition, if you store memories that are no longer useful, there’s a high risk that they will hamper the storage of new memories. Having fewer memories can also make it easier to spot important patterns that help us plan for the future. By remembering instances when traffic was bad on your commute, for example, you would learn which times to avoid. Remembering every single journey would make it impossible to identify such patterns. Even so, there are less practical reasons for forgetting, especially as we age. Our

DOES CLOSING YOUR EYES WHY IS IT THAT YOU ONLY TRULY HELP YOU REMEMBER? REMEMBER SOME THINGS WHEN OTHER PEOPLE TRIGGER THE MEMORY? Yes. Vision is our dominant sense and a key source of new information. When you try to think of something, seeing the world in front of you is a major distraction. So, closing your eyes helps limit the distraction, especially when you try to retrieve a highly visual piece of information. But it’s highly individual. Some people may find it works while others don’t. YY

40 | NewScientist | 27 October 2018

We store a lot more information in the brain than we can intentionally recall. What we can retrieve depends largely on the cues given, either from other people or the environment. If memories are a pile of jigsaw puzzle pieces, cues are the picture on

bodies simply aren’t adapted to living quite as long as we do, says Aoife Kiely from UK charity the Alzheimer’s Society. Aside from some new cells in the hippocampus, “the neurons you are born with are pretty much the ones you are going to live your whole life with”, she says. “It is certainly an issue of wear and tear of the brain.” As we age, we lose many of the connections between these neurons,

the box — it activates the connections that memory fragments are attached to. But sometimes, a friendly prompt can mess with your memory. Imagine you went to a concert with a friend who later said to you: “Remember they sang suchand-such song?” Each time you recall a memory, it becomes fragile and vulnerable to change. Even though you don’t actually remember, you’ve heard of this song, your friend looked very confident and you may end up convincing yourself about this experience. And this becomes a new memory (see “Can I trust my memories?”, page 36). YY

How can two people remember the same event differently? T IS the day after a blazing row and you are determined to clear the air. But the more you talk about the argument with your partner, the more you struggle to hide your incredulity. How can their recollection be so, well, wrong? It’s as if you are reading from different scripts. In some ways, you are. To understand how people can experience the same event but recall it so differently, we need to forget our assumptions about how memories work, says Signy Sheldon at McGill University in Canada. We tend to think of memories as information stored in the filing cabinet of the brain for future use. In fact, they are only built when we retrieve them. All the information you were bombarded with during that argument – what was said, the scene, your feelings and reactions – was just sitting there gathering dust. It wasn’t until you called the event to mind the next day that you created a mental representation of what happened. And of all the details you could have picked out, you can bet you didn’t focus on the same ones as your sparring partner. One reason for this is very basic. “We are now understanding that there are strong individual differences in how people remember,” says Sheldon. What’s more, these differences are etched in our brains. Hints at what is going on come from people who have aphantasia, the inability to form mental images in the mind’s eye. Unsurprisingly, such people’s memories also lack a visual component, even though they can recall facts. Sheldon and her colleagues wondered whether this might help in understanding the different ways other people remember things. Exploring this possibility, they asked people to complete a questionnaire about how they tend to remember, before having their brain scanned. The team found that people’s memory style was reflected in their brain connectivity. Those who were better at remembering facts had more physical links between the hippocampus, and the prefrontal cortex, which is involved in reasoning. Those with richly detailed “autobiographical memories”, by contrast, had more connectivity between the hippocampus and

and immune cells in the brain can also begin to run amok. Still, factors like health and education play a large role in how our memory fares as we age, Kiely points out. And even when memories seem to have disappeared, they are often still lurking somewhere, it is just that we can’t or don’t retrieve them – until the right moment comes along. Sam Wong and Catherine de Lange

WHAT IS PHOTOGRAPHIC MEMORY? Photographic memory is the ability to recall a past scene with great accuracy. Some people have better visual memory than others, especially those with highly superior autobiographic memory (HSAM). We don’t know why, but their memory seems to work the same way, yet is somehow better organised, so they can retrieve more details. But their memory isn’t perfect – flashbacks as real and precise as photos are a myth. YY




areas involved in visual processing. “People’s brains are wired differently depending on how they naturally approach the act of retrieval,” says Sheldon. Beyond individual brain differences, there are other reasons why two people might have conflicting memories of the same event. Their emotional response to it is one.

“We now understand that there are strong individual differences in how people remember” “Emotional events can be recalled much more naturally, almost like they are stamped in our minds,” says Sheldon. It is as if we shine a spotlight on the things that really matter to us. What we remember will also be affected by whether we consider it useful. And there are benefits to that too. It can help us learn lessons and bond with others. The malleability of memory is often seen as something that’s broken, says Sheldon, “but it’s really very adaptive”. Catherine de Lange 27 October 2018 | NewScientist | 41


I’ll make quantum reign supreme Quantum computers have phenomenal potential, and Michelle Simmons is making it real, says Phil Dooley

42 | NewScientist | 27 October 2018

What did it mean to you to win Australian of the Year as an immigrant?

To be recognised by my adopted country says much more about Australia than it does about me. To celebrate someone in this way, who wasn’t born here, speaks to the forwardlooking and positive outlook of the Australian psyche. My friends in the UK were amazed. What inspired your move to Australia?

In 1998, I was working at the University of Cambridge on quantum materials made from a compound called gallium arsenide, which was really unpredictable. Then I saw a Nature paper by Bruce Kane at UNSW that said if you were building a quantum computer, silicon would be the best material. I looked at Bruce’s idea and thought, if I was going build something, that’s the way I would do it. Technologically it was completely beyond the capability of the time, but the Australian team really decided, right, we’re going to try to build that. It was by far the best move I ever made. A lot of people internationally said “yeah, that’s great but none of that has been done before – good luck to you”. I enjoyed that, because a lot of the challenges were technological ones that I thought were likely to work out. What drew you to quantum computers?

Like many scientists, I seek universal knowledge that will bring us a better understanding of the world. But I am drawn to concrete things. Building such



he describes it as “an eye opener” – the childhood moment when Michelle Simmons’s father casually underestimated her ability at chess. She won the game in question regardless, but the moment stung. That someone so close to her didn’t appreciate what she was capable of became a motivating force. These days, no one is underestimating Simmons. Her drive and determination led the English-born quantum physicist to win the Australian of the Year award in 2018, highlighting the impact made by the scientist sometimes dubbed the “quantum queen”. The quantum computers that Simmons works on hold the promise of solving problems that would leave conventional computers whirring impotently until the heat death of the universe. In an industry rife with speculation and misinformation, she has built a team at the University of New South Wales (UNSW) in Sydney that has hit goal after technological goal along the road to delivering silicon-based quantum computers. Her team made headlines when it built a transistor made of a single atom of phosphorus, embedded in silicon. The phosphorus acts as a qubit, the unit of quantum computation. Unlike digital bits, which exist only as 0s or 1s, qubits can be both at once. After recently adding a second phosphorus qubit, Simmons’s team showed that they affected each other – a step towards quantum entanglement, the key to giving quantum computers their phenomenal power.

an understanding is especially rewarding if I can make something practically useful. A quantum computer will allow us to see the world in a different way and solve a host of problems, including some we’re not even aware of yet. Our society is dependent on so many complex systems, the more powerful the computing power we can marshal, the better. How do you go about making such a precise device?

Phosphorus is next to silicon in the periodic table so, using a scanning tunnelling electron microscope in an ultra-high vacuum, you can take a silicon atom out of a crystal and put a phosphorus atom back in its place. The phosphorus sits in the same site that the silicon would have been, but it has an additional electron. We are using the spin states of that extra electron as the qubit.

We can use the electric and magnetic fields around the phosphorus to affect that electron’s spin, so we can control it in three dimensions. We can even bring in a second phosphorus atom and look at the overlap and the entanglement. How on earth do you not lose an individual phosphorus atom?

It’s a technical achievement. To keep track of it after taking it out of the microscope, we make all kinds of markers on the transistor’s surface. We also needed to encapsulate that phosphorus atom in silicon to protect it, without having it move around during that process. The industry was very much of the

“A quantum computer will allow us to address problems we aren’t even aware of yet”

opinion “this is never going to work”, so our patent for how to keep an atom in place was very exciting. What are the challenges in scaling up to chips with multiple qubits?

One challenge in the qubit world is cross-talk, which happens if you try to engineer one qubit and inadvertently affect the one next to it, because it is so close. But we have recently demonstrated atomic engineering that beautifully isolates each one. So when will quantum computers become a useful reality?

We want to demonstrate a 10-qubit system by 2022. Then we are looking for between 10 and 100 qubits, which we want to do in the five years after that. I think that’s where the first commercial applications will come, if not before.

Then we will really be addressing the question: can you control the world at the atomic scale? And, if so, will that give you the predicted spin-up in computing power – the notion of quantum supremacy? No one has shown unequivocally that it is possible yet. Will I get a quantum laptop?

I’m not sure that you will. To understand and control the quantum world, you need very low temperatures, and exquisite control of the electric and magnetic fields – every parameter. It is likely to be a cloud-based quantum server that people would access through conventional computers. I must admit that when we began, we had this idea to build a universal system that anyone could program, but I’ve realised that’s a very utopic view, that’s a long way off. Q Phil Dooley is a science writer in Canberra, Australia 27 October 2018 | NewScientist | 43


Keep calm and evolve Many writers want to update Darwin. But facts are stubborn, says Matthew Cobb from this cross-species event. Lokiarchaea, it neatly took up its Nevertheless, Quammen does place on one twig of the tree of not nail his claim that HGT, or the microbial life, rather than being origin of eukaryotes, destroys the smeared all across it. usefulness of the tree metaphor. When a microbe acquires genes There is no need to fix Darwinism through HGT, only some of them in this respect. survive. Natural selection retains It is true that tracing the those genes that provide an evolutionary relations between microbes has become much more “Darwin thought changes to an organism during its complex since we discovered the lifetime could be passed extent of HGT between microbial lineages. Some arthropod species to its offspring” have also acquired genes from symbiotic microbes, slightly advantage and purges those blurring their position on the tree that do not. While the history of life. But we can still identify of a particular gene may show microbes and their relation to complex crossings between other organisms from their different microbial lineages, the genomes. Following the recent overall relations of microbes identification of a new group, the maintain a tree-like structure.

IN JANUARY 2009, at the start of the bicentenary of Darwin’s birth and the 150th anniversary of the publication of On the Origin of Species, the cover of this magazine proclaimed: “Darwin was wrong”. This bombastic declaration related to the discovery that genes can be passed “horizontally” between distant microbial species as well as in the usual way, “vertically” down the generations of a species. “Horizontal gene transfer” (HGT) means that when we study the evolutionary relationships of microbes, we can find a thicket of connections instead of the tree-like concept developed by Darwin. The Tangled Tree, by science writer David Quammen, adds some intriguing new discoveries to that story. One is the fact that viral DNA, trapped in our genomes, can sometimes, as a result of natural selection, lead to key adaptations, such as the mammalian placenta. Above all, the appearance of eukaryotic cells around 2 billion years ago came about through the apparently chance fusion of two unrelated microbes rather than through inheritance. As a result, the branch of life represented by eukaryotes – you, mushrooms, flowers and so on – is these days depicted as emerging Identical twins are never entirely identical, due to epigenetics 44 | NewScientist | 27 October 2018


The Tangled Tree: A radical new history of life by David Quammen, William Collins Lamarck’s Revenge: How epigenetics is revolutionizing our understanding of evolution’s past and present by Peter Ward, Bloomsbury

The general validity of Darwin’s tree metaphor is even clearer when it comes to animals. The first version of the human genome spectacularly claimed that we have acquired more than 200 genes through HGT. We didn’t. No vertebrate genome contains a significant amount of microbial DNA. Our chromosome structure and our immune systems help stop this from happening. One thing that Darwin definitely did get wrong was his understanding of inheritance. Like many of his contemporaries, Darwin thought changes to an organism during its lifetime could be transmitted to its offspring, hence his claim that blacksmiths’


For more books and arts coverage, visit newscientist.com/culture

Matthew Cobb is a zoologist at the University of Manchester, UK

Craft work


A new show reminds us science isn’t just there to be useful – it’s a kind of making, finds Simon Ings

What if we used movement to manipulate the mind? That’s the premise behind choreographer Matthias Sperling’s deliriously strange performance-lecture Now That We Know, 1-2 November at the Lilian Bayliss Studio in London.

Watch Seventy-two people died when fire consumed the Grenfell Tower flats in west London last year. On 30 October, The Fires That Foretold Grenfell on BBC2 tells the haunting story of five major blazes that forewarned of the tragedy.


sons have big arms. This view is now mistakenly identified with one of his predecessors, French naturalist Jean-Baptiste Lamarck. In reality, Lamarck’s version of this conception was semi-mystical, invoking the will or desire of the young animal to change. These basic, historical facts have escaped palaeontologist Peter Ward in his deeply misguided book Lamarck’s Revenge. He claims not only that Darwin was wrong, but that Lamarck, or the idea that he thinks was Lamarck’s, is right, as shown by modern research in epigenetics – a sexy term for gene regulation. This involves organisms responding to their own developmental stage, and factors such as environmental stressors, by turning some genes on and off, often by adding temporary chemical tags to DNA. In principle, this explains much of our physiology and growth, and why identical twins are not completely identical. Some say that these regulatory changes can be transmitted through many generations, driving evolution. Ward goes even further, bizarrely including HGT as an example of epigenetics and arguing, without any evidence, that everything from the rapid expansion of the mammals after non-avian dinosaurs became extinct to the human propensity for warfare can be explained by epigenetic evolution. The key stumbling block for this guff is that, in animals, there is no evidence that epigenetic effects can be inherited for more than a few generations. For epigenetics to have a role in evolution requires a mechanism to get from changes in gene regulation in tissue to enduring changes in gametes. Darwin spent years worrying about this and came up with a completely wrong answer. Ward does not even try. ■

Marion Nestle reveals an Unsavory Truth: How food companies skew the science of what we eat (Basic),

Dawns, Mine, Crystal by Yunchul Kim, Korean Cultural Centre, London, to 3 November. Some of the work also features at FACT, Liverpool, 22 November to 3 March

NOSTALGIA was not the first word that sprung to mind when I visited a show at London’s Korean Cultural Centre by South Korean artist Yunchul Kim. At first glance, indeed, Kim’s art appears intimidatingly modern. The new pieces exhibited were inspired by his residency last year at the CERN particle physics laboratory near Geneva, Switzerland. They centre around photonic crystals, colloids and particle detectors, and are placed in the context of earlier work, featuring eviscerated hard drives, pencil sketches of fluid flows and a “chemical synthesiser” turning the electrical current flowing through a droplet of seawater into a cloud of sound. But for the scientists who are Kim’s most committed audience (and eager collaborators), there is something wonderfully oldfashioned about the way he works. Kim’s studio in Seoul is full of materials: homemade ferrofluids,

gels, metals, all kinds of reagents, acids and oils. While labs (and not a few artists’ studios) grow more sterile and digital, his workspace remains stubbornly wedded to stuff. The artist’s wry description of his practice – “touching, staring, waiting for things to dry” – captures something of science’s lost materiality. Kim’s latest work (see above) shows a contraption in three parts that turns cosmic rays into bubbles suspended in space, a copper-aluminium sludge, stirred by hidden magnetic orreries, and a shattered gelatin rainbow. What are these but the results of a strange science that is the outcome of some spectacularly purposeless noodling? The physicists at CERN loved it, and Kim soon found out why: “I make all my own machinery, and so do they,” he says. “Their love of craft is everywhere, from the colour for their cabling to the careful labelling of everything.” Kim’s art is a reminder that science isn’t just there to be useful. It is also a craft. It’s something humans do, and something that, when presented this well, we are bound to enjoy. ■

while Donald Varene explores The Science of Cookery and the Art of Eating Well (Columbia).

Listen The Outside/In Radio podcast explores the natural world and how we use it. A two-part look at overpopulation asks why this once burning issue has become something you only seem to hear about from Marvel’s Thanos and other comic book supervillains.

Watch In cinemas from 2 November, Mirai (pictured) is a poignant Japanese animation fantasy about a boy who discovers a portal to other times, and long-vanished ancestors.

27 October 2018 | NewScientist | 45


The scandal of scholarship Expect some righteous anger as a new film exposes an unexpected con, says Graham Lawton


Paywall: The business of scholarship, directed by Jason Schmitt, can be viewed at paywallthemovie.com

TWO minutes into this riveting documentary, there’s a moment of cinematic genius. Just as the story is getting into its stride, THUD – down comes a paywall and a voice says: “We are sorry, you do not have the credentials to access this documentary. Please see payment options below.” You’re going to have to shell out $39.95 to keep watching. Of course, you don’t. The paywall is fake and, after a few agonising seconds, the film rolls on. But its impact is real, a mixture of “WTF?” and “How dare they!” This is precisely the reaction film-maker Jason Schmitt is aiming for, and what academics feel when butting up against paywalls that demand money in exchange for allowing them to read the latest research in their field. This research is likely to have been paid for by all of us, but has ended up out of reach behind a barrier. The story of how this happened is the stuff of Paywall, a movie whose unpromising material is unexpectedly spun into gold as we are carried on a rising tide of astonishment and righteous anger. By the end, you will be convinced scholarly publishing is one of the greatest cons ever. It is worth billions to publishers, who charge people to read their journals through fees or subscriptions. But neither comes cheap. Take Schmitt’s example, Biomaterials, an Elsevier journal. A sub costs around $10,700 a year. Individual articles on Elsevier’s Science Direct portal generally cost $39.95. These prices drive 46 | NewScientist | 27 October 2018

margins of some 37 per cent – nice have risen faster than inflation for for shareholders and the industry. years. Publishers sell discounted These fat margins are built on “bundles” of subs to libraries, but publicly funded research and free remove content without notice. scientific labour. The research, They also ask institutions to sign paper writing, peer review and non-disclosure agreements about journal editing are done by prices, ostensibly in return for a scientists funded by taxpayers. discount, so nobody knows what Yet the resulting research papers anyone else pays and collective somehow end up the intellectual “Scientists in poor (and property of the publisher. To add insult to injury, subs and even rich) countries can’t tolls are largely paid by university get at research they need, while publishers get rich” libraries, funded by… taxpayers. It’s not as if there’s competition, either. Scientists need access to all bargaining is impossible. Many journals, making them a licence scientists in poor countries (but to print money for the publishers. sometimes also in rich ones) can’t And to advance their careers, they get access to research they need, must publish in high-impact while the publishers just get rich. journals, mostly run on the There is another model, open toll-access model. access, but 20 years of insurgency There’s worse. For no reason have failed to smash the system. other than price gouging, costs Last month, however, 13 European

Paywall shows how publicly funded research is turned into private profit

research bodies, which together hand out €18 billion a year, unveiled a radical plan: from 2020, research they fund must be published in an open access journal, making it instantly available to everyone for free. Will this finally change the game? The evolving story is told mainly through talking heads, yet, amazingly, the passion and eloquence of the interviewees plus punchy editing keeps it exciting. And the film ends with a real bang as we meet Alexandra Elbakyan, the “pirate queen” of scientific publishing, who runs Sci-Hub. This website makes around 70 million paywalled research papers freely and easily available. Elbakyan has been sued by Elsevier and others, and is a fugitive from justice so her interview was a real coup. When Schmitt asks her opinion of Elsevier (Sci-Hub’s most pirated publisher), she delivers the film’s coup de grâce with her arch reply: “I like their slogan ‘making uncommon knowledge common’ very much, but as far as I can tell, Elsevier has not mastered this job well. Sci-Hub is helping them to fulfil their mission.” If I have any criticism of the movie, it is that it fails to capture the publishers’ story – if only to let them hang themselves. It also focuses too much on Elsevier, which, says Schmitt, declined to take part. This focus unfairly demonises one company and lets others off the hook. For balance, you should know that the giant does participate in open-access publishing, and that publishers accept the problem and the need for change – in part to dodge the bullets fired by exposés such as this. ■

Position Title: Research

Associate Professor

Req # 03919

Department of Chemistry at The University of Chicago invites applications for the position of Research Associate Professor. The successful candidate will be responsible for maintaining a research program and advise graduate students in Theoretical or Computational Chemistry. The candidate is expected to collaborate with experimental and/or theoretical faculty within the department. Ideally, candidates should have demonstrated ability to raise support for their research and lead collaborative projects. *HUKPKH[LZT\Z[OH]LHKVJ[VYH[LPU*OLTPZ[Y`VYYLSH[LKÄLSK HSVUN ^P[O H[ SLHZ[ Ä]L `LHYZ VM WVZ[NYHK\H[L YLZLHYJO HUK teaching experience in Chemistry. The successful candidate will have demonstrated competence in teaching, and have experience mentoring graduate students in Chemistry. Candidates must have evidence of publication and research dissemination. Applicants must apply online at the University of Chicago’s Academic Jobs website https://tinyurl.com/yd8tkptv, and must upload a curriculum vitae and cover letter. Review of applications will begin November 15, 2018 and will JVU[PU\L\U[PS[OLWVZP[PVUPZÄSSLK ;OL