May 14 - 20, 2016 New Scientist

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INFINITY MACHINE If this computer stops, 150 years of math is wrong

EMOTIONAL CONTAGION Other people’s feelings are playing on your mind

PARADISE LOST How Antarctica went from lush forest to frozen waste WEEKLY May 14 -20, 2016

FACE LIFT Can plastic skin really make you look younger?

WHAT IS INFORMATION? Everything is made of it – but we’re only just figuring out what it is

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Science and technology news www.newscientist.com US jobs in science

GRAVE GOODS The 10 most important human burials

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Professor Dame Carol Robinson 2015 Laureate for United Kingdom

By Brigitte Lacombe

Science needs women L’ORÉAL UNESCO AWARDS

Dame Carol Robinson, Professor of Chemistry at Oxford University, invented a ground-breaking method for studying how membrane proteins function, which play a critical role in the human body. hroughout the world, exceptional women are at the heart of major scientiic advances. For 17 years, L’Oréal has been running the L’Oréal-UNESCO For Women In Science programme, honouring exceptional women from around the world. Over 2000 women from over 100 countries have received our support to continue to move science forward and inspire future generations. JOIN US ON FACEBOOK.COM/FORWOMENINSCIENCE

CONTENTS

Volume 230 No 3073

This issue online newscientist.com/issue/3073

Leaders

News 5

8 An invisible polymer claims to make people look younger

News 6

UPFRONT New map of Mercury. Canada’s raging wildfire. Pacific islands sunk by rising seas. Smoggy? Still worth walking 8 THIS WEEK Turing machine could break the math if it stops. Goopy dark matter slowed universe. Season the seas to save corals. How lush Anarctica turned to ice 15 IN BRIEF Stripped super-Earths. Robot surgery. Men sleep less than women. $2 superbug test

CULTURA RM EXCLUSIVE/LIAM NORRIS/GETTY

Smart skin rids you of wrinkles

Driverless cars are here – utopia or dystopia? Let’s take the empathy crisis seriously

On the cover

Analysis

28

9

Infinity machine If this computer stops, we’ve got math all wrong 32 Emotional contagion Beware how others feel 13 Paradise lost Antarctica, from forest to frozen wasteland 8 Face lift Plastic skin to undo ageing 36 Grave goods Our most amazing burials

What is information? Everything is made of it – but we’re only just figuring out what it is

18 The new philanthropists Silicon Valley cash is flooding into science – but is it useful? 20 COMMENT Embryo research limits must reflect facts What to make of autism’s new “cure” 21 INSIGHT Why finding bitcoin’s founder still matters

Technology

Cover image No shadow, Makoto Tojiki

22 Fleets of driverless cars roll out around the world. Your emails shed light on your darkest secrets

Features

26 The romance of amateur stargazers

Aperture

36

Features 28 What is information? (see above left) 32 Emotional contagion Other people’s feelings tug on your heartstrings 36 Grave goods (see left) 40 PEOPLE John Matherly exposes every vulnerable device on the web

The 10 most important human burials

PER-ANDRE HOFFMANN/AURORA PHOTOS

Grave goods

Culture 44 Shadows on the wall Why did early humans cover caves with vivid images? 45 Don’t fence us in Hedgerows turn out to be an education in natural sciences

Coming next week… Ripe for life The solar system that’s friendlier than our own

Real life King Kong

Regulars 52 LETTERS Dark dimples in baby galaxies 56 FEEDBACK Quantum leap masterclass 57 THE LAST WORD Dino DNA

Meet the greatest of all great apes

14 May 2016 | NewScientist | 3

Entries for $250,000 Ryman Prize now open The Ryman Prize is a unique international award aimed at encouraging the best and the brightest thinkers in the world to focus on ways to improve the health of older people. The world’s ageing population means that in some parts of the globe – including most of the Western world – the population aged 75+ is set to triple in the next 30 years. In order to stimulate fresh efforts in the field, the Ryman Foundation is offering a NZ$250,000 (US$165,000) annual prize for the world’s best

discovery, development, advance or achievement that enhances quality of life for older people. The inaugural Ryman Prize was won by Gabi Hollows for her pioneering work to provide affordable eye surgery for people in developing countries. The Hollows Foundation has restored sight to more than 1 million people – an amazing achievement that has transformed lives. If you have a great idea, or have achieved something remarkable like Gabi, we’d love to hear from you!

Go to www.rymanprize.com for more information

Gabi Hollows and Nobel Laureate Dr Erwin Neher at the presentation of the inaugural Ryman Prize

www.rymanprize.com

ELLIOTT ERWITT/MAGNUM PHOTOS

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Driving blind again We need to plan ahead for the autonomous car revolution

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AUTONOMOUS cars are just around the corner. Cities across the world are rolling out pilots of driverless vehicles, and soon motorists in Germany will be able to relax on the autobahn as their cars drive them from Munich to Berlin (see page 22). In other words, we are on the brink of a transport revolution as potentially radical as the one that began in 1908 with the Model T Ford. By 1931 the automobile’s transformative power was so clear that Aldous Huxley imagined the people of his Brave New World worshipping Henry Ford as the creator of their dystopian society. Huxley was on to something. The Ford revolution changed Western society. It fuelled urban

sprawl and led to the remodelling of cities to prioritise the motorist; urban freeways and motorways carved up the suburbs. Car worship, as we know, has also led to rampant air pollution and gridlock. It almost singlehandedly created the oil industry: before mass car ownership, petroleum was a worthless byproduct of kerosene lamp oil. Now it feeds vast amounts of carbon dioxide into the atmosphere. Highways are a death trap: an estimated 1.25 million people die every year in vehicle accidents, the vast majority a result of human error. But this was and is considered a price worth paying. Cars equate to personal freedom and

Hooked on a feeling THIS may have passed you by, but the world is in the midst of an empathy crisis. Psychologists first drew attention to it in 2009 with research finding a far lower degree of empathy among university students than in their 1970s counterparts. That research lit the blue touch paper on what is becoming an industry. Exhortations are rolling in to teach empathy in schools, to

pupils and teachers alike. The Pope says we should build a global culture of empathy. Even the Wall Street Journal, the house journal of hard-headed capitalism, published a how-to guide. It is easy to dismiss such notions as psychobabble. But there is evidence that our responses to human distress are malfunctioning. Emotive media coverage puts us at risk of

convenience, and keep the economy moving. Today we have a chance to rid ourselves of the bad while keeping the good. Autonomous cars could be everything that human-controlled cars are not: safe, smart, cheap and clean. How will our cities and society change as a result? It seems unlikely that driverless cars will produce a transformation on the same scale: they are still just cars after all. But who knows. The Model T Ford was “just” a horse-drawn carriage without a horse. By 2031, we may be living in another brave new world. Whether it is a dystopia is something we should be thinking about now. ■

“empathy burnout”, blunting our ability to feel other people’s suffering (see page 32). In our media-saturated world, that is food for thought. But we also need to clarify what we mean by empathy. Can you really measure it? Is it possible, or necessary, to distinguish it from compassion and altruism? The terms are often used loosely, and interchangeably. Before we rush headlong into solving a crisis of feeling, we first need to solve one of meaning. ■ 14 May 2016 | NewScientist | 5

JAMES MORGAN/PANOS

UPFRONT

Rising seas sink 5 islands GOING, going, gone. Five of the Solomon Islands have been swallowed whole by rising sea levels, offering a glimpse into the future of other low-lying nations. Sea levels in the Solomon Islands have been climbing by 7 millimetres per year over the last two decades, due to a double whammy of global warming and stronger trade winds. “It’s a perfect storm,” says

in the Solomons. Five islands present in 1947, ranging in size from 1 to 5 hectares, had disappeared by 2014 (Environmental Research Letters, doi.org/bg54). Another six had shrunk by 20 to 62 per cent, confirming reports of locals. The most populated of these, Nuatambu Island, is home to 25 families, who have witnessed 11 houses wash into the sea since 2011. The global rate of sea level rise

Simon Albert at the University of Queensland in Australia. “There’s the background level of global sea level rise, and then the added pressure of a natural trade wind cycle that has been physically pushing water into the Western Pacific.” Albert and his colleagues analysed aerial and satellite images from 1947 to 2014, focusing on 33 reef islands

is 3 mm per year, but is likely to accelerate to 7 mm by the end of the century, as rising temperatures melt ice sheets and cause thermal expansion of the oceans, Albert says. “All the projections show that in the second half of the century, the rest of the globe will reach the rate of sea level rise that the Solomon Islands is currently experiencing,” he says.

–The islands are vanishing –

Walking to work SHOULD you walk or get the bus? The healthiest option depends on which city you live in – but the more active option is almost always best. We are often encouraged to drive less and walk more, but many cities – like London – have troubling air pollution statistics that can leave people wondering which of their commuting options is really best for their health. Now a study has weighed up these factors. Taking breathing

“Even in Delhi, you’d have to cycle 5 hours a week for the smog to negate the benefit of the exercise” rates into account, James Woodcock at the University of Cambridge and his team combined data on the effects of exercise on life expectancy with pollution readings from cities all over the world. They have concluded that walking and cycling are almost always the better options for a 6 | NewScientist | 14 May 2016

person’s health. This is the case in London and most other cities, where it is always better to be active than to take a more sedentary option like a bus, train or driving a car (Preventative Medicine, doi.org/bg8x). The exceptions are some of the most polluted cities – including Delhi in India, Karachi in Pakistan and Doha in Qatar. But the team found that even in Delhi – the most air-polluted city in the world – people would need to cycle for more than 5 hours a week before the harm from the smog outweighed the health benefits of the activity. However, people with long commutes, or who work as bicycle couriers, are likely to cross this line. Woodcock says we still need to take urgent steps to reduce pollution levels. “Pollution causes thousands of deaths a year. You’re breathing all this in whether you’re exercising or not,” he says. If more people switch to walking or cycling instead of driving for the sake of their health, this will also bring down the amount of air pollution says Woodcock. “That’s a big win-win.”

Mercury mapped READY for a close-up? The team behind NASA’s Messenger mission to Mercury has released the first global topographic map of the solar system’s innermost planet. It came just in time for the little planet’s big show. Messenger orbited Mercury from 2011 until 2015, and took 300,000 images and millions of spectra. It measured the heights of hills and depths of craters with a laser, but because the spacecraft had an eccentric orbit, it didn’t do

this for the southern hemisphere. Now, the team has combined more than 100,000 images to create a model of the whole planet. It includes the highest point – 4.48 kilometres above average elevation, south of the equator in some of Mercury’s oldest terrain – and the lowest point – 5.38 kilometres below average elevation, in the volcanic Rachmaninoff basin. The map was released just days before Mercury crossed in front of the sun from the perspective of Earth, on 9 May.

Journey to the ocean’s bottom THE expedition has only just begun and already it is producing stunning footage of Earth’s deepest abyss. NOAA’s Okeanos research ship will spend the next two months cruising the seas above the Mariana trench, using sonar systems and a remotely operated vehicle (ROV) to explore the little known parts of the trench and its surroundings. Footage from the daily dives is being live-streamed, with highlights posted on the expedition website.

The trench is famous for being the deepest in the world, but the ROV will not be going 11 kilometres down to the very bottom, as James Cameron did in 2012. It can only reach down to 6 kilometres, where it has been exploring hydrothermal chimneys and life around them. The cameras snapped pricklefish at nearly 5 km, Crossota jellyfish (pictured) at a depth of nearly 4 km, as well as various bits of rubbish, including a beer can at 3780 metres.

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

Facebook legal row

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60 SECONDS

No marten can stop it Not even furry animals can hinder the world’s biggest experiment. The Large Hadron Collider is back in action for its 2016 run, after a short delay when a beech marten knocked out the power. This is the collider’s second year of gathering data at higher energy levels .

STOP that tag! A judge ruled last week that a US class-action lawsuit arguing that Facebook’s use of facial recognition tech violates Illinois law will go ahead, despite the company’s attempts to dismiss it.

“The company is effectively creating ‘faceprints’ – digital scans that identify individuals”

Like owner, like dog?

NOAA OFFICE OF OCEAN EXPLORATION AND RESEARCH, 2016

Last year, a group of Facebook users in Illinois filed a civil complaint, claiming that the way Facebook’s AI can auto-tag photos violated the state’s Biometric Record evacuation Information Privacy Act. BIPA IT IS the largest evacuation of prevents companies from collecting biometric data without its kind in the country’s history. obtaining and retaining a person’s Close to 90,000 Canadians have consent, among other guidelines. been forced to leave their homes around the city of Fort McMurray Photos don’t typically fall into over the past week due to a the category of biometric data. huge wildfire. But the plaintiffs argue that The fire has burned through an Facebook is effectively creating area covering at least 1570 square “faceprints” – digital scans that kilometres, prompting a state of identify individuals – which emergency in Alberta. Though should fall under BIPA’s purview. rain and cooler temperatures Facebook tried to dismiss the began to slow the fire’s spread on case, countering that its terms of service bound it only to California “We may be turning a and federal laws – not those of corner but it’s too early Illinois. But on 5 May, a judge to celebrate. This beast threw out that argument. is a difficult problem” If Facebook loses it could have big implications for the industry, which is exploring many different Sunday – a week after it started – applications for facial recognition. it is still raging and may take months to extinguish. “We may be turning a corner, but it’s too early to celebrate,” said Ralph Goodale, the country’s minister of public safety. “This beast is an extraordinarily difficult problem.” Recent hot and dry weather probably kick-started the fire. More broadly, climate change seems to have had an effect, too, leading to longer fire seasons. “It’s unusual to see an earlyseason fire get this severe,” says Merritt Turetsky of the University of Guelph in Ontario. This higher and more prolonged –Rolling in the deep– risk of fires could be the new

–Alberta ablaze–

normal for Canada, she says. Though some 2400 buildings were lost, 85 per cent of the city remains intact. There is no set timeline for returning the evacuees. The fire will incur up to CA$9 billion (£4.8 bn) in damage, according to one estimate, which if correct would make it the most expensive natural disaster in Canada’s history.

Troubled plants PLANT habitats are changing and more than 20 per cent of all terrestrial plant species are now at risk of extinction. That’s according to the first global assessment of plants, by the Royal Botanic Gardens, Kew, in London. The team used data from global conservation monitor the IUCN to estimate the number of threatened plants, and assessed land cover using satellite images taken between 2001 and 2012. Mangroves saw the greatest change, with more than a quarter of their area transformed over the decade – often to shrimp farms or golf courses. While human activity was the main driver, climate change is having a large impact, says Kathy Willis, Kew’s director of science. “We really need to stop and think what we’re doing about land planning on a global scale.”

No wonder Labradors are so fat: they have mutations in a gene linked to hunger in humans. More than 300 Labradors had their weight and desire for food studied, and nearly a quarter carried a mutant form of the POMC gene (Cell Metabolism, doi. org/bg8w). Each mutant copy of the gene made a dog 1.9 kilograms heavier on average.

Zika caught in action The Brazilian strain of the Zika virus has been shown to cross the placenta in mice, and restrict fetal growth, including signs of microcephaly (Nature, DOI: 10.1038/nature18296). It is the first experimental evidence that Zika can cause birth defects – though there has been a strong association for some time now.

Armchair ecology Photos of animals taken by amateur photographers could replace traditional research methods. After looking at nearly 5000 Google images of black bears, barn owls and other animals, researchers found they could map their colour variations just as accurately as they could through fieldwork (Methods in Ecology and Evolution, DOI: 10.1111/2041-210X.12562).

Go with your gut Put down the yogurt. A review of studies on probiotic products suggests that in healthy people, there is little evidence they have any effect on the mix of gut bacteria, as measured by analysing faecal samples (Genome Medicine, doi.org/bg82).

14 May 2016 | NewScientist | 7

THIS WEEK

Paste on beauty that’s skin deep HAD enough of those bags under your eyes? Try some polymer skin. A new invisible wearable polymer called Second Skin seems to act like a younger-looking layer on top of your face. It lasts for days, and, over time, may even reshape your face, according to the team that developed it. “This would be Spanx for your face,” says Anne Lynn Chang, a dermatologist at Stanford University in California who was not involved in the research. But many are sceptical, and say they cannot judge whether the

“No wonder it took nine years. They really took the time to look at all the parameters of skin” material really does reduce sagging and swelling without seeing more evidence. The polymer skin is the latest in a slew of scientific approaches to make people look younger. But compared with efforts to tinker with our metabolism and cellular structure, simply pasting new skin over your old could almost seem old fashioned. The polysiloxane polymer was developed by Robert Langer at the Massachusetts Institute of Technology and his team, working with spin-off company Olivo. It is designed to mimic the properties of youthful skin – including its elasticity and ability to reflect and scatter light beneath its surface to give a youthful glow. “No wonder it took nine years,” says Adam Perriman, who works on biomaterials at the University of Bristol, UK. “They really took 8 | NewScientist | 14 May 2016

the time to look at all the parameters of skin.” First, you layer a silicone polymer cream onto your face, then a platinum catalyst that crosslinks the molecules in the cream. The resulting skin is reportedly breathable and locks in moisture. A 25-person pilot study has found that it can be worn for more than 24 hours without discomfort (Nature Materials, doi.org/bg75). “You don’t realise it’s on you,” says Langer. Second Skin is more contractile than the real thing, lifting up the skin it is painted on. When applied onto the bags under a person’s eyes, the skin seems to tighten, and the wrinkles around it appear reduced. “From their photos, the skin looks five to 10 years younger,” says Christopher Griffiths, a dermatologist at the University of Manchester, UK. However, it is hard to tell from the team’s low-resolution photos what the polymer does to the skin, says Griffiths. It could be pushing the fat under the eyes back, or

CULTURA RM EXCLUSIVE/LIAM NORRIS/GETTY

A polymer skin has been developed to cover wrinkles and lines. Sally Adee investigates

–Pasting back the years–

suppressing fluid-based swelling. “I’m not sure what’s being improved,” he says. The skin is a departure from the general trend in cosmetic science, which is moving towards trying to change the skin from within, rather than masking the surface. Some creams are designed to

QUEST FOR COLLAGEN Collagen holds our bodies together. But we produce less of this connective tissue as we age, leading to sagging jowls and eye bags. Collagen creams, designed to replace the protein by smearing it on the skin surface, are popular. But Christopher Griffiths, a dermatologist at the University of Manchester, UK, says these are unlikely to work, because they can’t penetrate to the right layers of the skin.

There are also collagen pills and supplements. But no robust studies have shown that eating or drinking concentrated collagen works, says Griffiths – stomach acid would break it down before it can get to your skin. How about injecting it? Again, Griffiths thinks the collagen probably gets broken down. So for now, despite the hype, no product seems capable of replacing our lost collagen.

help older skin reflect more light by hydrating the outer layer of dead skin cells, but they can only do so much – the physical differences between young and old skin go deeper. Collagen and elastin fibres in the lower dermis layer are what give skin its elastic recoil and firmness, but after our teenage years, we lose about 1.5 per cent of our collagen a year – a process that is accelerated by sun damage and smoking. There is now a growing industry in ingestible collagen (see “Quest for collagen”, left), but there is doubt over whether any available products give you any benefit, says Griffiths. Other projects aim to attack skin ageing at a cellular level. Insilico Medicine in Baltimore, Maryland, is using machine learning to identify compounds

In this section ■ Goopy dark matter slowed universe, page 10 ■ How lush Antarctica turned to ice, page 13 ■ Fleets of driverless cars roll out around the world, page 22

to combat ageing. The company has assembled some of the largest databases of drugs and gene expression in the world, says CEO Alex Zhavoronkov, and is scouring these for clues with machinelearning algorithms. Insilico Medicine is now developing a sunscreen. “Some of our major collaborators are cosmetics companies,” says Zhavoronkov. Later this year, the company plans to launch a line of nutritional supplements that purportedly protect against some of the cellular processes of ageing.

Turing machines test foundations of maths ONE hundred and fifty years of mathematics will be proved wrong if a new computer program stops running. Thankfully, it’s unlikely to happen, but the code behind it is testing the limits of the mathematical realm. The program is a simulated Turing machine, a mathematical model of computation created by codebreaker Alan Turing. In 1936, he showed that the actions of any computer algorithm can be mimicked by a simple machine that reads and writes 0s and 1s on an infinitely long tape by working through a set of states, or instructions. The more complex the algorithm, the more states the machine requires. Now Adam Yedidia and Scott Aaronson of the Massachusetts Institute of Technology have created three simulated Turing machines with behaviour that is entwined in deep questions of mathematics. This includes the proof of the 150-year-old Riemann hypothesis – thought to govern the patterns of prime numbers. Turing’s machines have their origins in a series of philosophical revelations that rocked the mathematical world in the 1930s. First, Kurt Gödel proved that some mathematical statements can never be proved true or false – they are

In one area – slowing or stopping ageing – cosmetic approaches are overlapping with medicine and some drugs are already showing potential. The diabetes drug metformin, and rapamycin – derivatives of which are used to suppress the immune system and for cancer therapy – both seem to extend lifespan. Even Google is planning to take on ageing through its longevity research spin-off, Calico. But for some, a skin-deep approach might be preferable. The fact that Second Skin doesn’t enter the body or attempt to stop ageing may be part of its appeal, says Perriman. Langer even says that Second Skin may improve the structure of a person’s underlying skin after repeated use, but he is reluctant to go into details until he has conducted more studies. It’s not that implausible, says Perriman. “Heavily hydrating like this over time could really make the skin start to look better,” he says. “The forces exerted will realign collagen fibres and improve elasticity.” For now there is something we can be certain about. Everyone ages and a huge proportion of the globe is interested in trying to slow that process. Allowing people to hold back the years is, and will continue to be, big business. ■

DANIELLE DONDERS/GETTY

Ageing business

undecidable. He essentially created a mathematical version of the sentence “This sentence is false”: a logical brain-twister that contradicts itself. Gödel’s assertion has a get-out clause. If you change the base assumptions on which proofs are built – the axioms – you can render a problem decidable. But this comes at the cost of making other problems undecidable. That means there are no axioms that let you prove everything. Following Gödel’s arguments, Turing proved that there must be some Turing machines whose behaviour cannot be predicted under the standard axioms – snappily known as ZFC – underpinning most of mathematics. But we didn’t know how complex they would have to be. Now, Yedidia and Aaronson have created a Turing machine with 7918 states that has this property. And they’ve named it “Z”. “We tried to make it concrete, and say how many states does it take before you get into this abyss of unprovability?” says Aaronson. Z is designed to loop through its 7918 instructions forever, but if it did eventually stop, it would prove ZFC inconsistent. Mathematicians wouldn’t be too panicked, though – they could simply shift to a slightly

stronger set of axioms. The pair have also created two machines that will stop only if two famous mathematical problems, long believed to be true, are actually false. These are Goldbach’s conjecture, which states that every even number greater than 2 is the sum of two prime numbers, and the Riemann hypothesis, which says that all prime numbers follow a certain pattern. The latter forms the basis

“How many states does it take before you get into this abyss of unprovability?” for parts of modern number theory, and disproving it would be a major, and unlikely, upset. Expressing mathematical problems as Turing machines also has a practical benefit: it helps to work out how complex they are. The Goldbach machine has 4888 states, the Riemann one has 5372, while Z has 7918, suggesting the ZFC problem is the most complex of the three. Yedidia and Aaronson want to see if Z can run with fewer instructions – something Gödel and Turing are likely to have wanted to know. “They might have said ‘that’s nice, but can you get 800 states? What about 80 states?’” Aaronson says. “I would like to know if there is a 10-state machine whose behaviour is independent of ZFC.” Jacob Aron ■

–Theories could fall like dominoes– 14 May 2016 | NewScientist | 9

THIS WEEK

Goopy dark matter slows the universe would affect the early universe. Cosmologists’ favourite view of the universe’s earliest moments involves it going through an exponential growth spurt in the first slivers of a second after the big bang. This expansion, called

A GOOPY form of the dark stuff that makes up the majority of the universe’s matter could have had a weird effect on its early evolution – and make ripples from the big bang easier to spot. Dark matter is the mysterious substance that makes up 80 per cent of the universe’s matter, yet it only interacts with ordinary matter through gravity. The most popular candidate for this stuff is the WIMP, or weakly interacting massive particle, but searches for it have come up empty. There are other candidates. Paul Shapiro at the University of Texas at Austin and his colleagues have looked at an alternative idea of dark matter made from particles called bosons. Unlike WIMPs and ordinary matter, bosons can share the same quantum state – a property that also lets them clump together in a Bose-Einstein condensate (BEC). This strange, goopy state of matter allows all the particles to move in lock-step as a single quantum object. Now, Shapiro and his graduate student Bouha Li have worked out how this form of dark matter

Adding minerals to oceans could cut acidification BETWEEN a rock and a hard place? A last-ditch approach to slow ocean acidification may involve spreading a mineral along coasts to suck acidifying protons out of the water. Earth’s oceans are now 25 per cent more acidic than they were before the industrial revolution, due to excess carbon dioxide in the air dissolving to form carbonic acid. This acidification is 10 | NewScientist | 14 May 2016

ESA/PLANCK COLLABORATION

Lisa Grossman

threatening a wide range of marine organisms, including corals, because it makes it harder for them to build their skeletons and shells. Francesc Montserrat of the Royal Netherlands Institute for Sea Research and his colleagues say a natural mineral could mop up acid in seawater. Olivine, a magnesium silicate mineral, gradually swaps its magnesium ions for protons in the water, helping to remove acidity. Montserrat and his colleagues studied this effect in small seawater tanks, which were designed to mimic the marine ecosystem. When a

inflation, would send relativistic ripples through space-time called primordial gravitational waves. Physicists thought they had seen evidence of these waves using the BICEP2 telescope in 2013, but it turned out to be a mistake. Earlier this year, though, the LIGO experiment saw gravitational waves from colliding black holes, proving that such waves really exist. In the standard picture, primordial gravitational waves

would be so small that LIGO would never be able to see them. In the new model, it has a chance. Although goopy dark matter behaves exactly the same as WIMPs in modern times, Shapiro and Li’s calculations suggest that in an earlier phase, the goop changed from acting like matter to behaving like radiation. Go back even further, and the dark matter stiffens, behaving even more strangely. “There’s a pressure associated with trying to disturb it,” Shapiro says. “When you clump it, it wants to push back. It’s like we filled the universe with a fluid.” That stiffness of this strange, goopy dark matter would have held back the expansion rate of the universe at that time, so it would have slowed its expansion more quickly. But primordial gravitational waves would shoot through the infant universe at the same speed as before. That means they would show up more easily against the background, making them easier to spot. In a talk at the American Physical Society meeting in Salt Lake City, Utah, last month, the pair claimed that such dark matter could suppress expansion enough for primordial gravitational waves to be visible to LIGO. “Our model says there’s still –Background noise– hope,” says Li. ■

1.5-centimetre layer of ground up mineral was applied over a base of natural sediment, the pH of the seawater fell by the desired amount, with no adverse effects on life. However, when a 3-centimetre layer was used, organisms in the sediment died. “This goes to show that it is a sensitive process that we have to work out,” says Montserrat, who presented the work at the

“The fact we’re starting to see changes in our oceans suggests we need these tools in our arsenal”

International Symposium on the Ocean in a High-CO2 World in Hobart, Australia, last week. He is now in talks with the Dutch government about testing the safety and efficacy of this method in a real-world coastal setting. “The fact that we’re already starting to see detectable changes in our oceans suggests that we certainly need these sorts of tools in our arsenal,” says Andrew Lenton at CSIRO, Australia’s national research body. One key issue to address is whether the effects of olivine could be reversed if it began to harm the environment, Lenton says. Alice Klein ■

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THIS WEEK

From lush to slush in 40 million years Andy Coghlan

ANTARCTICA was once covered with tropical forests. Now researchers have fully charted the slow transition from tropical paradise to icy wasteland, thanks to a single marine sediment core. It shows for the first time that temperate forests were a key transitional stage before falling temperatures turned the continent into a white wasteland. The core was taken from the sea floor off Wilkes Land in East Antarctica as part of the Integrated Ocean Drilling Programme. Pollen grains found inside show how vegetation on the continent changed between the early Eocene, around 54 million years ago, and into the Miocene, 12 million years ago. “The core from Wilkes Land is the first to give the entire story from the Eocene all the way through,” says Ulrich Salzmann of Northumbria University in Newcastle upon Tyne, UK, who presented preliminary results at the European Geosciences Union meeting in Vienna last month. “It seems that vegetation had disappeared completely by 12 million years ago.”

The core’s story starts in much warmer climes, around 16 °C, in the early Eocene. Back then, the climate was subtropical, the verdant landscape dominated by palms and trees such the monkey puzzle. By the early Oligocene, around 31 to 33 million years ago, the palms and monkey puzzles had disappeared. They gave way to more temperate species, including

“Lush, green Antarctica finally gives way to ice some 12 million years ago, as temperatures drop” Huon pines, trees known as living fossils that still thrive in New Zealand and Tasmania. For trees, the transition from the Oligocene to the Miocene 23 million years back was the beginning of the end. Podocarpus trees and southern beeches remained, but their territory was increasingly being invaded by mosses and other plants that are the hallmarks of tundra. The temperatures dropped to around 6 °C by this period. “Tundra starts to take over,” says Salzmann. “The vegetation moves down to the lowlands and

–Seabed cores store history-

the tundra becomes dominant. The landscape became very similar to that seen today in Tierra del Fuego in Patagonia.” But the end for all greenery came around 12 million years ago, when even the tundra disappeared. “Then, the glaciers took over and turned Antarctica into a white desert,” says Salzmann. “Wilkes Land must have been the last refuge of woody vegetation.” “It’s a super-exciting find, and opens the door to this new look at Earth’s history in the Antarctic,” says Jörg Pross at the

University of Heidelberg in Germany. “This is particularly important in light of anthropogenic climate change, with Antarctica warming up quickly and its ice sheets becoming potentially unstable.” But he says that even though Saltzmann’s core is a great start, it is like trying to use a single core from Europe to say what the entire continent’s climate was like, from southern Spain up to Norway. “To get a grip of what happened, more drill cores around Antarctica are needed.” ■

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A career in science, it’s not always what you think From movie advisor to science festival director, where will your science career take you?

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IN BRIEF

Dancing electrons make radar bounce

Sea slugs march north, hinting at US climate shift WARM waters in the Pacific Ocean are encouraging dozens of species of nudibranch sea slugs to head north at a surprising pace. They seem to have made the journey in just a year. This could signal the beginning of a major climate shift in the region, says marine biologist Jeffrey Goddard at the University of California, Santa Barbara. His team tracked the northernmost sightings of 30 nudibranch species along the US coast during 2014, when a large portion of the eastern Pacific Ocean was unusually warm – a phenomenon that came to be known as “the blob”. Nine species were found further north than

they had ever been seen, such as Okenia rosacea, pictured – which usually lives south of San Francisco but was seen as far north as Oregon. The rest were spotted at or near the most northerly longitudes they have been seen at (Bulletin of the Southern California Academy of Sciences, doi.org/bgd3). Nudibranchs are excellent indicators of shifts in ocean temperatures and currents, says Goddard. He thinks their movement may be an early indication of a big shift in the Pacific Decadal Oscillation (PDO), a long-term pattern of climate variability. The last PDO shift was in 1977. It caused warmer temperatures in the north-west US, fewer storms in the south-east, and reduced precipitation in the west – conditions that persisted for about a decade.

Superbug detection for just $2 a pop DETECT, control and contain. We now have a way to rapidly detect whether a patient has picked up a bacterial infection in hospital. The device could help doctors quickly treat infections, and slow the rise of deadly superbugs like MRSA. It takes between three and five days to get the results from standard tests for bacterial infections. This gives time for the bacteria to spread and for the

patient’s condition to worsen. Now Hakho Lee of Harvard Medical School and his team have developed a portable device that can detect five of the most common infections in hospitals – including E. coli. The device can also tell if any Staphylococcus aureus present is the drug-resistant strain MRSA. More than 50,000 people die from drug-resistant infections

in Europe and the US every year. The device can analyse a sample of mucus or other fluid in hours, sending the results straight to a physician’s phone. It works by reading the genetic sequences of bacteria, determining which species are present in a sample – and it costs just $2 a time. When tested on nine patients who were showing signs of infection, the device was as accurate as standard tests (Science Advances, doi.org/bgrz).

IT’S an invisible wall. For 50 years, physicists have puzzled over why some radar signals sent skywards bounce back 150 kilometres above the ground. It now seems it is down to vibrating electrons. The bounceback was first seen in 1962. It appears daily and is stronger during solar flares and weaker during solar eclipses. To investigate it, Yakov Dimant and Meers Oppenheim at Boston University modelled how ultraviolet light from the sun strips electrons from oxygen and nitrogen molecules in the upper atmosphere. The loose electrons vibrate, generating waves that ripple through the electrons and the oxygen and nitrogen ions. They aren’t strong waves, says Oppenheim. “They are more like the froth on the top of water, when a heavy wind blows over it.” But they are strong enough to reflect radar beams (Geophysical Research Letters, doi.org/bgfh).

Stars strip the air from super-Earths SOME worlds get stripped by their stars. Skirting too close can cause them to shrink when their puffy atmospheres get ripped away. Super-Earths are rocky worlds between Earth and Neptune in size. All seem to orbit far from their host stars, but no one could explain why. Now Mia Lundkvist at Aarhus University in Denmark and her colleagues have measured the diameters of 102 stars, to better gauge the size of their planets. They confirmed a lack of superEarths close in, which they think is because intense radiation has boiled away their atmospheres (arxiv.org/abs/1604.05220). The planets lost so much of their bulk that they appear Earthsized – no longer “super” at all. 14 May 2016 | NewScientist | 15

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

IN BRIEF

Dragonfly wings Robot surgeon stitches up solo after operation can track radiation IT’S at the cutting edge. For the colleagues overcame this by robot, which a surgeon controls.

ROSS HODDINOTT/NATUREPL

16 | NewScientist | 14 May 2016

first time, a robot has successfully operated on live soft tissue without human intervention. The surgeons who developed it hope that in three years it will be ready to perform routine surgeries such as removing an inflamed appendix or blocked gall bladder. Operating on the bowel and internal organs is tricky because soft tissues move and slide around, making it hard for a robot to track their position. Peter Kim at the Children’s National Medical Center in Washington DC and

giving their robot a 3D camera and near-infrared vision. “The robot can see more than humans can,” says Kim. When the team coated a pig’s guts in fluorescent tags, the robot used near-infrared light to home in on its target by monitoring the tags’ positions. That meant it could stitch together tissue after it had been surgically cut. Once the robot had operated on four pigs, the team compared its handiwork with that of a real surgeon as well as the da Vinci

They say their robot performed better on several measures, including evenness of the suture spacing and repairing the guts in a way that lowers the likelihood of leakage (Science Translational Medicine, doi.org/bgrq). “The risk of a patient dying after an operation goes up by five to 10-fold if the gut leaks, so this could potentially prevent complications,” says Kim. But the robot is much slower than a surgeon, something the team now hopes to improve on. ELLIOTT ERWITT/MAGNUM

HUMBLE insects may be called to bear witness to the next nuclear accident. Shining UV light on their wings can tell us how much radiation they have absorbed. Staff at nuclear plants carry instruments that track exposure to radiation. But most of us don’t have these devices. Testing materials in fingernails or the glass of a cellphone is useful, should we have the misfortune to be near a leak. But insects can also do the job, says Nikolaos Kazakis of the Athena Research Centre in Xanthi, Greece. To prove the concept, he and his colleagues exposed the wings of dragonflies and houseflies to different doses of radiation, which ejects electrons from atoms in the wings. Each electron leaves behind a “hole”, which acts as particles in its own right. As electrons and holes move, they may recombine, emitting a flash of light. Shining UV light on the wings nudges them to recombine. By recording the flashes, Kazakis and colleagues could measure radiation doses (Radiation Measurements, doi.org/bgd4). There’s some concern that sunlight could make the electrons and holes recombine early. But Kazakis has his eye on insects that keep their wings under cover: cockroaches.

Earth’s air was once thin on the ground CLIMBING Mount Everest is a bit like travelling back in time. Earth’s atmospheric pressure 2.7 billion years ago may only have been a quarter of what it is now – equivalent to conditions 2000 metres above the 8848metre summit of Everest. The finding challenges the traditional view that a thick atmosphere helped keep Earth warmer than today, at a time when the sun was less active. Sanjoy Som, now at the NASA Ames Research Center, and his team used holes in frothy lavas deposited 2.7 million years ago to estimate the air pressure at the time. Their results show it was up to half of what we measure today, with 23 per cent being the most likely value (Nature Geoscience, DOI: 10.1038/NGEO2713). Som thinks early life sucked nitrogen from the air, locking it up in sediments. Only once oxygen became abundant 2.4 billion years ago did life started oxidising ammonium, releasing nitrogen and bulking up the atmosphere. If so, greenhouse gases must have kept Earth warm in the interim, when the sun was only 80 per cent as bright as today.

App gives low-down on global sleep DID you sleep well? The answer may depend on your age, location, gender and exposure to light. Daniel Forger at the University of Michigan in Ann Arbor and his team looked at the sleep patterns of 5000 people worldwide. The team obtained their huge data set via Entrain, a smartphone sleep-tracking app. The data covered users’ bedtime, waking time, time zone and daytime light exposure. The team found that middle-aged men sleep the least, while women under the age of 25 sleep the most. Women as a whole appear to sleep

for 30 minutes longer on average than men, going to bed slightly earlier and waking up slightly later. The time when people woke up was the factor most strongly linked to total sleep time, suggesting that a job requiring an early start every day can reduce sleep. Daylight exposure was linked with increased sleep – perhaps because outdoor jobs are more tiring. Where people lived mattered too. People in Singapore, for example, sleep for an average of 7.5 hours a night, while Australians get 8.1 hours (Science Advances, doi.org/bgrp).

INTRODUCING THE SECOND IN A NEW SERIES OF WHITE PAPERS FROM NEW SCIENTIST What’s the future of business? We at New Scientist decided to take a look at how three of the key drivers of business – energy, money and automation – might change over the next decade. To do that, we’ve asked three writers with deep understanding of these areas to tell us how they think the future could unfold, and how it might confound our initial expectations. The author of our second GameChangers report in the series is Steven Cherry, who for 15 years covered the work sector for IEEE Spectrum, and now directs TTI/Vanguard, a members-only forum that explores the impact and implications of future technologies for senior business leaders. In his report, Cherry examines the arguments for and against the idea that automation will ultimately outsource every human job, and explores the paradoxes inherent in both. If cognitively complex jobs are the only ones that are safe, why is there still such high demand for cashiers? If automation generates new jobs, why is GDP slowing? And when can you expect the robots to take your job? To find out, register to download your free copy of GameChangers: Automation and Artificial Intelligence today.

Sally Adee Editor, GameChangers

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ABOUT THE AUTHOR Steven Cherry is the Director of TTI/Vanguard, a membership forum based in New York that explores future technologies. Previously he was a journalist and editor at IEEE Spectrum, the magazine of the Institute of Electrical and Electronics Engineers. Prior to that he was an editor at the Association for Computing Machinery (ACM). He founded and co-hosts the award-winning podcast series, Techwise Conversations, which covers technology news, careers and education, and the engineering lifestyle.

GAME CHANGERS AUTOMATION AND ARTIFICIAL INTELLIGENCE IN THIS EXCLUSIVE NEW REPORT FIND OUT:

] Why every technological breakthrough takes twice as long as we expected, but we’re still not prepared for its arrival ]Why GDP is an increasingly limited tool for measuring productivity, and what that means for jobs and automation ] Which jobs might be safe – and which won’t

ANALYSIS BILLIONAIRE SCIENCE

The new philanthropists Silicon Valley bigwigs are falling over themselves to donate to science – as long as they can call the shots. Is this the best way forward, asks Jacob Aron HACK cancer. Visit the stars. Cure all diseases. Land on Mars. In 2016, it seems as if every other week a billionaire announces they have stumped up the cash to tackle a long-standing challenge that mere mortal scientists have failed to crack. Science gets a handsome injection of funds and the donor secures their legacy. But should we welcome the rich stepping up or question the motives behind research backed by the 1 per cent? Wealthy patronage of science took off in the 19th century but these days things are a little different. Rather than writing a

hopes will get drugs to patients faster and fund PICI in the future. Not to be outdone, Facebook founder Mark Zuckerberg has said he and his wife Priscilla Chan will donate 99 per cent of their shares in the company to the Chan Zuckerberg Initiative, which will “advance human potential”, including a goal to “cure all diseases by the end of this century”. Such immense donations are to be welcomed, especially when the alternative is to blow the cash on yachts, private jets and other trappings of a billionaire’s lifestyle. But their influence doesn’t necessarily make for plain sailing. Lacking the wider view of government funding agencies, the wealthy can end up weighting research towards their own interests, in a way that might not deliver the best results, says Fiona Murray at the Massachusetts Institute of Technology. Months

“Slick PR can make it seem like there is a wondrous future, if only government would get out of the way”

18 | NewScientist | 14 May 2016

SILICON VALLEY HEAVYWEIGHTS

SAUL LOEB/AFP/GETTY

NET WORTH $44.6 billion SOURCE Facebook DONATIONS 99 per cent of Facebook shares over his lifetime to the Chan Zuckerberg Initiative, which aims to cure all diseases, improve education and fight climate change

YURI MILNER

BILL GATES

JEMAL COUNTESS/GETTY

MARK ZUCKERBERG M.BENITEZ/REX/SHUTTERSTOCK

cheque and getting their name on a building, like the Rockefellers and Carnegies of old, today’s tycoons practise “venture philanthropy”, modelled after the venture capital that funds Silicon Valley tech firms. “The time horizons are much shorter, the outcomes are well defined, and often the philanthropists are heavily involved in the process,” says Benjamin Soskis at George Mason University in Virginia. Take Sean Parker, Napster founder and Facebook’s first president. Last month, inspired by his own experience with allergies and autoimmune disease, he pledged $250 million to set up the Parker Institute for Cancer Immunotherapy (PICI), bringing researchers from 40 US labs to work on cancer treatments that “reawaken” the immune system. PICI will be in charge of managing all intellectual property created by the researchers, which Parker

before Parker’s announcement, the US government revealed its own Cancer Moonshot 2020. “Do we need that many things about cancer?” says Murray. “Maybe we need to focus on other diseases, Alzheimer’s, Parkinson’s. Are we focusing enough on woman’s health issues, which often don’t get the same amount of time and attention?” The lack of high-profile cash for women’s health reflects the fact that billionaire donors are a fairly homogenous bunch: white men. “It’s a major problem. Medical funding is almost entirely devoted to first world diseases,” says Soskis, though there are exceptions – the Bill and Melinda Gates Foundation has channelled billions into global development, for example. And these men like to stick together. “People like that tend to back well-known scientists, so you worry these mechanisms don’t

NET WORTH $75 billion SOURCE Microsoft DONATIONS $28 billion to the Bill and Melinda Gates Foundation, which funds global health and development projects, including tackling malaria

NET WORTH $2.8 billion SOURCE Investments in Facebook, Twitter, Whatsapp, Spotify DONATIONS $200 million for Breakthrough Initiatives, a collection of research efforts looking for alien life

help you get diversity of ideas or approaches,” says Murray. That said, billionaires do back ideas that can’t get money elsewhere. This includes rare diseases that governments or drug firms are unable or reluctant to fund, such as the tropical diseases that the Gates Foundation targets, but also more esoteric pursuits that taxpayers wouldn’t stomach.

Set for the stars The hunt for intelligent aliens has long been privately bankrolled by Silicon Valley – the SETI Institute in California has received cash from some of the founders of Hewlett Packard, Microsoft and Intel. Entrepreneur Yuri Milner recently pledged $200 million to the cause. Half will go towards searching for alien signals, the rest to exploring the possibility of getting uncrewed spacecraft to Alpha Centauri, our nearest star. Sending probes to the stars is a lifelong dream, says Milner. “This idea never went away from the time I was a child, but it’s only in the last few years because of some lucky investments that I was able to think about it practically.” But is it really a good use of resources? “Milner’s spending decisions seem driven by personal interests, more than the public’s interests,” says Linda Billings of George Washington University. Milner is, of course, free to spend his money how he pleases. But there’s a danger that Silicon Valley’s slick PR machines skew public perception of the feasibility of such projects, making it seem like a wondrous future is around the corner, if only the state would get out of the way. “They all adhere to this neo-liberal ideology:

An audience with the rich and famous

KEVIN MAZUR/GETTY IMAGES FOR PARKER MEDIA

Sumit Paul-Choudhury, the Vatican

SEAN PARKER NET WORTH $2.4 billion SOURCE Facebook DONATIONS $600 million to the Parker Foundation, $250 million of which will fund the Parker Institute for Cancer Immunotherapy

the government should leave us alone; technological progress is inevitable, necessary and always beneficial,” says Billings. “Science projects funded privately can sometimes take more risks than those paid for by taxpayers,” says Mark McCaughrean at the European Space Agency.“The problem comes when private initiatives amp up the hype to a point where they give the misleading impression that they’re unconstrained by technical and financial practicalities – or even the laws of physics,” he says. “That can make taxpayer-accountable research appear mundane by comparison, risking dwindling public support.” And these ambitious plans don’t always work out. In 2013, billionaire Dennis Tito announced

IT WAS one hell of a double act, if you’ll pardon the phrase: a keynote address given by the vice president of the United States – followed by a speech from Pope Francis. Their remarks were addressed to a small crowd, by the standards of the Vatican’s audience chamber, but a distinguished one: pioneering researchers, visionary technologists, dignified patients – and deep-pocketed philanthropists. They were assembled for a glitzy three-day conference on regenerative medicine orchestrated by the New York-based Stem for Life Foundation and the Pontifical Council for Culture, –Proud founder of a cancer institute - intended to catalyse funding and “reduce human suffering throughout funding for a crewed fly-by of the world”. Its centrepiece, the papal audience, epitomised how the new Mars by 2018, stating the project wave of precision medicine sits at the could be achieved provided we nexus of science, society and money. were willing to take greater risks The science was cutting-edge. than those allowed by NASA Delegates heard about bold advances bureaucracy. In the end, Tito in the use of stem cells to treat rare asked NASA to partner in the diseases. There was also time mission. It rejected the offer. dedicated to new cancer treatments Now another billionaire, SpaceX CEO Elon Musk, is forging and to organ repair. It was difficult not to be moved by stirring accounts of his own path to Mars, last month announcing he intends to land an miraculous cures, and talk of how the uncrewed vessel on the surface by convergence of big data, gene editing 2018. Rather than funding research and targeted therapies will create an “inflection point” for medicine. through philanthropy, Musk But the programme didn’t touch all founded SpaceX as a business, with aspects of this unfolding revolution. the long-term goal of colonising There was little mention of the the Red Planet. But its major devastating failure of some early gene customer to date is NASA, which has given SpaceX billions towards therapy trials, and certainly not of the the development of its spacecraft, repeated scandals that have dogged stem cell research – exacerbated by and will provide support for the huge financial pressure to deliver Mars mission. This suggests the results, in the view of some delegates state still has a role to play. I spoke to. That sort of bad publicity Ultimately, both governments tends to spook funders. and philanthropists need to get Nor was there so much as a whisper better at spending money, says about using stem cells from human Murray, perhaps by combining embryos, which the Catholic church Silicon Valley experimentation staunchly opposes. And the emphasis with research on funding itself. on curing children – the Vatican line “We need to examine how we being that it is unconscionable to turn allocate funding, and the degree away from “innocents’ pain” – wasn’t to which we make good or bad mirrored by discussion of genetic choices,” she says. ■

screening, whose likely consequence, abortion, is also anathema. While there wasn’t much overt religiosity in evidence during the two days I attended, nor did there seem to me to be much deep engagement with ethical and social questions. So is this just a well-heeled talking shop, or do deals get done? “You definitely want outcomes,” was how one fundraiser put it bluntly to me. That’s why US vice president Joe Biden was there: to drum up support for his $1 billion Cancer Moonshot. His forceful address called for a global coalition to address the “constant emergency” of cancer, but his project is likely to be spurned by Republicans back home. That leaves Biden looking for private-sector support. Fortunately for him, funds are pouring into this area. Sean Parker, who made his fortune from Facebook, was on hand to explain why he set up an eponymous Institute to encourage knowledge-sharing among cancer researchers, bankrolled with his own cash. “Many of us in Silicon Valley have got bored of making consumer-focused products, mostly for teenagers,” he said. So he had looked for a way to use his skills in the services of a more profound effort. The mix of boosterism, worthy

“Pope Francis addressed a distinguished crowd, including deep-pocketed philanthropists” causes and peerless bragging rights made for a well-crafted appeal to plump wallets, particularly those of Catholics. For those who are neither wealthy nor religious, it’s hard to argue with megabucks for medical research: it’s less nakedly selfaggrandising than many other pet projects of billionaires. But I was still left wondering how usefully the money raised would be spent – and about the prospects for research that might not tug at the heartstrings – and the wallets – of the rich and famous. ■ 14 May 2016 | NewScientist | 19

COMMENT

Don’t toss out the biology The 14-day limit on embryo research is a political one. Any rethink should not ignore the scientific facts, says Jane Maienschein HOW long should we let human embryos be grown in the lab? Until now that question has been largely academic. Survival beyond seven days was very rare, with nine days the longest achieved. Now two studies have managed 12 to 13 days before destroying theembryos, suggesting it might be technically possible to go past the 14-day limit that many countries have. Magdalena Zernicka-Goetz at the University of Cambridge, who led one of the studies, told a press conference that we may learn much of value by studying embryos past 14 days. But she stressed that this is a matter for society at large, and that she was not calling for the limit to be extended. “I have no view on that right now,” she told New Scientist. Even if researchers are not yet calling for this, the latest work will no doubt raise arguments about

personhood and the sanctity of life – all of which will distract from serious discussion of how embryo research might improve our understanding of developing life. How did we get here? The UK’s 1984 Warnock report reinforced talk of a 14-day limit by pointing to the appearance of an alignment of cells around that time known as the primitive streak, described as early organisation that will lead eventually to the nervous system. This stage is also the point beyond which twinning is impossible, so some argue that it marks the start of a new individual. Definitions of personhood are socially negotiated. Facts about development are not. The identification of 14 days as crucial was socially constructed and is not biologically definitive. Embryos develop at varying rates, depending on factors such as temperature. One embryo might

Give and take? I fear brain stimulation may diminish my “autistic advantage”, says John Elder Robison MANIPULATING your brain with magnetic fields sounds like science fiction. But transcranial magnetic stimulation (TMS) is already approved as a therapy for depression in the US and UK. More controversially, it is being studied as a way to treat classic symptoms of autism. With interest and hopes rising, it’s 20 | NewScientist | 14 May 2016

I had always been blind to. That sounds great, so why the controversy? Relieving depression isn’t controversial; it causes great suffering. I too felt I suffered – from emotional disconnection. But altering “emotional intelligence” to ease that is close to changing the essence of how autistic people think. Emerging brain therapies like TMS have great potential. Several of my fellow volunteers emerged with new self-awareness and

under the spotlight at this week’s International Meeting for Autism Research in Baltimore, Maryland. I can bear witness to the power of TMS. As someone with Asperger’s, I tried it for “Altering ‘emotional medical research, describing its intelligence’ is close to impact in my book Switched On. changing the essence of After TMS, I could see emotional how autistic people think ” cues in other people – signals

lasting changes. I think some of us have a degree of emotional insight that we didn’t have before. Initially I would have had TMS again. But doubts have now crept in. At first I thought only of easing disability. Now I find myself speculating about what might be lost in the process. The parts of my brain blind to emotional cues were doing other things – like giving me my instinctive understanding of machines. Might TMS, while apparently altering social cognition, interfere with such abilities? Science has no answer yet. Socially disadvantaged as I may have been, my insight into

For more opinion articles, visit newscientist.com/opinion

Jane Maienschein directs Arizona State University’s Center for Biology and Society and is a fellow of the Marine Biological Laboratory in Massachusetts. Additional reporting by Michael Le Page at New Scientist

machines made me a success. I wouldn’t trade it for anything. There will be autistic adults who choose TMS to try to improve social connectivity. Fine. They can choose freely. My concerns are for children. I can look back on my life and see how autism shaped me for good and bad. A teenager or parent may only see the disability. I’m concerned that they may choose TMS without knowing what they might be giving up. TMS raises many ethical issues. Let’s start talking about them. ■ John Elder Robison is author of books about autism including Look Me in the Eye and Switched On (Random House)

INSIGHT Bitcoin

KRISTINA UFFE

be much further developed at 14 days than another. So, whether we look at 12, 13, 14, or more days doesn’t matter. The question is: what is the embryo at that point? In a glass dish, it is largely undifferentiated, has no neural structure and is not viable. Unless and until implanted, it cannot live on its own. The critical point is that an embryo in a dish is a bunch of cells in a dish. When implanted, it is a growing and differentiating collection of cells in a uterus, increasingly connected with and dependent upon that uterus for the exchange of nutrients and waste products. Implantation is vital; mothers are vital. Only at about eight weeks does the embryo become a fetus with essential organs at least roughly mapped out. The nervous system develops much later, and only much, much later does the fetus have the capacity to feel pain. A primitive streak is not a nervous system. A bunch of cells is not an organised human in any robust biological sense. A number of days does not define life. ■

–Wright all along–

TherealSatoshicould makeorbreakbitcoin AN AUSTRALIAN entrepreneur called with investigative journalists so far Craig Wright has spent the past few fingering a Japanese mathematician, a Finnish sociologist, and the creator months trying to prove that he is of Silk Road – the online black market. someone hitherto known as Satoshi There are at least two reasons why Nakamoto. Last week he abandoned this matters. The less important one his quest, but it is still important to reveal who Satoshi really is. is that the inventor of the currency Satoshi Nakamoto is the would have been generating (“mining”) pseudonym of the presumed creator bitcoin back when it was very easy to of bitcoin, a digital currency that is earn what would now be thousands of dollars in a few seconds. As a result, essentially a form of virtual cash. Satoshi is estimated to hold a million Wright hired a PR firm to sell himself bitcoins – worth around $450 million to the BBC, the Economist and GQ as today, and amounting to roughly oneSatoshi, and set up an elaborate proof demonstration in a London hotel room. He also wrote a blog post setting out “Ultimately, the episode tells us little about Satoshi his claim. or bitcoin, but a lot about Within minutes of his story going how trust works online” live, Wright’s proof was torn apart by encryption experts and the bitcoin community. Patrick McKenzie, a widely twelfth of all bitcoins now in existence. This translates into huge influence respected programmer, posted his over the bitcoin market. attempt to verify the proof, showing The more important reason is that that it failed. Security researcher Dan Satoshi would have the loudest voice Kaminsky posted evidence that the in debates over how bitcoin ought to digital signature which Wright said be run. And the community is currently proved he is Satoshi was actually embroiled in its biggest one yet. copied from a web page of the public record of bitcoin transactions. What makes bitcoin so special is its Speculation over the identity of incorruptibility. Every transaction is bitcoin’s creator has gone on for years, automatically and indelibly recorded

in a public ledger, shared across thousands of computers on the bitcoin network. Transactions are gathered into what is known as a “block” and added to the ledger. The blocks are mined by setting computers hard mathematical problems, with a new block created only when one is solved. The community is split over the size of these blocks – and thus the number of transactions that can be added in one go. So called “little-blockians” want block sizes to stay small so that anyone with a computer can work with the currency. “Big-blockians” want bitcoin to be universal, handling transactions on the scale of banks. The problem with boosting the block size accordingly is that ordinary computers would no longer be able to help mine the currency. Having Satoshi come down on one side of the argument or the other would tip the balance. Ultimately, the Wright episode tells us little about Satoshi or bitcoin, but a lot about how trust works in the online age. Having other humans vouch for you is not enough. To prove his claim, all Wright had to do was to encrypt text with a private key that we know Satoshi used, and publish this online for anyone to verify. But he didn’t do it. “I broke,” Wright wrote on his blog after taking down his debunked proof. “I do not have the courage.” When it comes to bitcoin, courage has nothing to do with proof. Hal Hodson ■ 14 May 2016 | NewScientist | 21

TECHNOLOGY

I am your guardian angel This year fleets of driverless cars will roll out on public roads in cities around the world for the first time. Hal Hodson sits back and enjoys the view THE French Riviera is lovely at this time of year. I’m zipping along the coast in an old Honda Civic. The steering wheel spins to take the car round a bend – but my hands stay in my lap. And since there’s no need to keep my eyes on the road, I’m free to enjoy the beachfront view. An oddly pixelated man with a two-dimensional windsurfer under his arm gives me the eye. Sadly, my Riviera is being projected on a large wrap-around screen in a room-sized simulator

Coventry and Bristol will lead the way. Similar projects are happening in other cities around the world, including Singapore; Austin, Texas; Mountain View in California; and Ann Arbor in Michigan. One of the things driverless cars need is highly detailed maps,

INTERIOR DESIGN Cars that are essentially chauffeurs (see main story) are the vision of self-driving cars we are most familiar with from sci-fi films. They are also the vehicles that will change our relationship with cars the most. These vehicles don’t need a steering wheel. They find their own way. Passengers can even ignore the outside world if they choose. “If you look at what a full autonomous experience would be, it offers many more possibilities of what a car’s interior can be,” says Dominique Taffin at Yanfeng Automotive Interiors, one the world’s leading suppliers of car interiors, such as the panelling and instruments that adorn the inside of a vehicle. “You would have a radically

22 | NewScientist | 14 May 2016

MERCEDES BENZ

“Guardian angels will never fully take control but will instead jump in to stop you doing something stupid” in Wokingham, UK. As the car navigates the windy road, Nick Reed at the Transport Research Lab sits next to me and talks about the plan to deploy driverless cars in Greenwich, London, by the end of the year. The Gateway project will see London become one of the first cities in the world to have driverless vehicles. The number and exact routes they will take have still to be decided, but a few months from now you will be able to jump into an autonomous pod (see picture, top right) and be ferried to your destination along public roads. “It’ll be the first chance the public has had to experience driverless cars,” says Reed. “Not just the people on board, but the people sharing the space with them.” This is the beginning of a revolution in transport, as the cars roll out slowly in small pilots in urban areas. In the UK, Greenwich, Milton Keynes,

and these are being developed for each of the pilot cities. The islands of precision mapping will then fan outwards from urban hubs along primary roads. Mapping firm TomTom says it has already covered 28,000 kilometres of roads in Germany with sufficient resolution for driverless

different approach to how people behave in a vehicle. The size and shape can be different, seating could be different,” he says. It is not yet clear whether people would prefer to sit or stand, for example. “You could compare it to a hotel or a house where the interior design is going to be tailored to what people want from their experience – leisure, professional or tourist,” he says. Safety will be ultimately constrain the interiors of cars. If autonomous software can be made so trustworthy that seat belts and airbags are no longer needed, the possibilities open up even further. “Sofas, beds, whatever,” says Taffin. But time will tell. “We will discover how our behaviour changes when we have autonomous vehicles on the road.”

cars – 4 per cent of all the roads in the country. “Things like the Gateway project – where we’re going to have fully driverless cars, but operating only in certain environments – can happen quite quickly,” says Reed, as we drive over the cobbles of a small French town. “The environments in which the vehicles work will gradually become broader and more complex.” Reed’s vision involves just one of two very different kinds of autonomous car that will hit our roads in the next year or so. The Toyota Research Institute, led by Gill Pratt, calls these two types “guardian angel” and “chauffeur”. The autonomous passengerferrying pods we will see in cities are chauffeurs. Guardian angels, on the other hand, are cars that will never fully wrest control from a human but will jump in to stop you doing something stupid.

Sensors and software

Every car in Toyota’s 2017 fl et – from the most basic model up – will have the sensors and software required to run in guardian angel mode. Sensors will enable automatic emergency braking, for example, allowing the car to stop itself if it detects an imminent collision. Even the cheapest Corolla will not smash into the car in front, says Pratt. Data from the sensors in all of its cars will be fed into Toyota’s central data centre in Plano, Texas. Toyota’s artificial intelligence researchers will then use this to train their AIs how to drive on a wider variety of roads than are –Are you sitting comfortably?– being considered in pilot

GATEWAY PROJECT

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–My pod or yours–

schemes like the Gateway project. Ultimately, data gathered from guardian angel systems will help build cars that can drive as chauffeurs on any road. “Our cars drive a trillion miles a year, which is a lot of data,” says Pratt. Both types of self-driving car should save lives. In the UK alone, 17,000 people are killed every year on the roads. Globally, the number is 1.25 million. “That’s seen as acceptable and we’ve kind

of tailored our lives around that being OK,” says Reed. “But I don’t think it is OK.” Driverless cars could also have large social benefits, helping less mobile people get around. “It’s one of the reasons that Greenwich as a local authority is so keen to look at ways it can meet the needs of a growing population and an ageing population,” says Reed. In places like Greenwich, the demographic poised to increase

the most over the next 20 years involves people over 65. One problem governments want to address is how older people can be cared for at home for longer. Using autonomous vehicles to drive them around could be a big help. “It would be a kind of super dial-a-ride, basically,” says Reed. In general, however, consumer expectations will dictate the way we use driverless cars, says Reed (see “Interior design”, left). “If

UBER URBAN NETWORKING For all the hype about self-driving cars, they are just one part of a larger revolution in urban transport. Instead of focusing on making cars autonomous, increased automation behind public transport services is easing our movement through the world in other ways. Both transitions are happening at the same time. Last month, popular transport routing app CityMapper launched a feature that knits together Uber

pickups and the public transit network. CityMapper will send an Uber car to pick you up at just the right time to catch the train you need several kilometres away. Pick your destination, press a button, and simply follow the instructions to make your way across a city without having to think about it. As large systems like Uber and Transport for London link up, getting a person from A to B starts to look like

sending data across the internet. That might prompt some of the same questions about fairness raised by the “net neutrality” debate, which is concerned that all online traffic be treated equally. “If I’m a big executive and I need to get to my meeting across London in 15 minutes, can I pay a superpremium price that will change all the traffic lights and ensure I get freedom of my route?” says Reed.

people in cars want to work or relax or watch films, then engineers can find ways to make the cars safe enough.” If the pods in Greenwich are anything to go by, the size and shape of vehicles may change too. Yet the width of roads and aerodynamics will still constrain what is possible. “You can imagine completely different forms, but you probably can’t have a car 4 metres wide and 1 metre long,” says Dominique Taffin at Yanfeng Automotive Interiors, Cologne, Germany. “Cars are rather unique things,” says Pratt. “They’re an isolation chamber that you sit in for 1 or 2 hours a day.” That’s a very odd thing to do, he says. When we no longer need to drive them ourselves, we are free to reimagine completely what we want to do with that time and space. “How can you turn driving from a dreadful experience to a wonderful experience that you would look forward to?” ■ 14 May 2016 | NewScientist | 23

ONE PER CENT

TECHNOLOGY secret-keepers tended to be more socially active than expected – they were “hypervigilant”, says Tausczik. “A lot of the previous literature would have suggested social withdrawal.” raising suspicion.” To get round In particular, they took great this, the team decided to look at care to maintain relationships people’s emails. with those they wanted to keep Most participants had secrets in the dark, sending them more that were romantic or sexual in emails per month after they had nature – involving adultery or a secret than before. undisclosed homosexuality, The study also looked at for example. Some were hiding people’s relationships with those medical problems. Others had who knew their secret. Secretsecrets that they felt would destroy keepers tended to mirror the their school or work lives if known. language of their confidants Even so, all agreed to give the much more, suggesting closeness. The team will present the work at “They took great care to the International Conference on maintain relationships Web and Social Media in Cologne, with those they wanted Germany, this month. to keep in the dark” David Markowitz at Stanford University thinks the team has researchers access to their email found a clever way to get at accounts. After scrubbing the hidden information. “Email emails of identifying information, is an important platform for the researchers combed through understanding deception because the language used in more than it bridges social and professional 59,000 messages. Using software worlds for many people,” he says. to analyse the text revealed that The study shows how secretkeepers attempt to hide the fact they have a secret by trying to act normally. But liars often miss the target when trying to act like someone telling the truth, he says. Markowitz found this when he looked at research papers that had been retracted due to scientific misconduct. These tended to have more references than papers describing legitimate results. This kind of research could pave the way for systems that detect deception automatically, says Norah Dunbar at the University of California, Santa Barbara. At the moment, we are still trying to figure out if there are recognisable linguistic patterns at all. “But I think the long-term goal for a lot of people in this area is to be predictive,” she says. It is tempting to think that an algorithm can detect something fishy, says Markowitz. But to spot secrets automatically we need to monitor more than just language –Nothing to hide?- use, he says. Aviva Rutkin ■

Got a secret? Watch what you say in emails

24 | NewScientist | 14 May 2016

Desert rain Dubai has no shortage of sky-high structures but it may be planning its biggest construction project yet: an artificial mountain. Roelof Bruintjes at the US National Center for Atmospheric Research told website Arabian Business last week that his team is being funded by the United Arab Emirates government to look into the optimal size and location of a mountain to encourage rainfall. The team’s initial report is due in a few months.

272 m The number of stolen email

passwords that Wisconsin-based firm Holden Security persuaded a Russian hacker they dubbed “The Collector” to hand over in exchange for social media “likes”

Robot swot No cheating! A robot made by Lin Hui and colleagues at an artificial intelligence company in Chengdu, China, is reportedly being trained to sit the 2017 entrance exams for China’s top universities. The robot will take three exams – in maths, Mandarin and a combined humanities paper, including history, politics and geography – and hand in its answers on paper via a printer.

GERALD DONOVAN/ARABIAN EYE

DEAN BELCHER/GETTY

IT SOUNDS like the plot of a good soap: unknown to her family, a woman is running a phone-sex business from home. Only her best friend knows the truth. But she is one of 61 participants in a study looking at the way we cover up secrets in our emails. The results suggest we aren’t as good at hiding them as we think. Yla Tausczik at the University of Maryland in College Park and her colleagues recruited people who said they had kept an “enormous secret” in the last seven years. They posted flyers in major cities, sent out emails and posted ads online. The response was pretty high: 1133 people completed an initial questionnaire. Of these, 61 ultimately took part. Studying secrets is tough, says Tausczik. “You can’t bring people with secrets into the lab, you can’t bring in their friends without

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APERTURE

26 | NewScientist | 14 May 2016

The backyard stargazer IN A garden shed in Arcen, the Netherlands, amateur astronomer Harrie Rutten awaits the moment when an asteroid is due to pass in front of a star. At the appointed time, the star disappears, reappears… then winks out again. It turns out the asteroid was part of a binary pair. “By doing this observation himself, focusing on one point in the sky, he proved the hypothesis of a Brazilian astronomer,” says Nick van Tiem, who spent a year photographing amateur stargazers in haunts ranging from garden sheds to swamps to snowy fields. In a new book, The Star Disappeared, he tries to show why five of them go to the lengths they do. In some ways, the amateurs are more in touch with their subject than the pros. Over the past century or so, professional astronomy has moved from the observatory into the computer lab. Observations are made and processed by machines, and many of the most prolific telescopes are in orbit, with no eyepiece that a human can look through. But the amateurs have stuck it out, converting their sheds into observatories equipped with red lights to preserve night vision (pictured left). And they still make valuable contributions to science. They help track potentially dangerous space rocks (NASA uses their data to move its satellites to safety), discover new asteroids and comets, track the varying brightness of supernovae, and are often among the first to notice when something odd happens – like the star disappearing twice. But van Tiem thinks that’s changing. As technology advances, amateurs are less and less necessary. The community is also ageing, and fewer observers now have the skills or patience to take useful data. His photos are partly a way to preserve this moment as the group fades, and also to encourage it to keep going. Van Tiem’s book includes 26 pages of infographics and charts – a how-to guide for stargazers of the future. “People are still watching the sky, are buying telescopes, are interested,” he says. “That will stay.” Lisa Grossman

Photographer Nick van Tiem nickvantiem.nl

14 May 2016 | NewScientist | 27

COVER STORY

The

unseen agent

Information perplexed us for decades, but we’re inally unpicking its role in reality. Stephen Battersby reports

W

E LIVE in the age of information. We are surrounded by it, and more of it year by year. It is the currency of human understanding, our indispensable guide to navigating a complex world. But what, actually, is information? As we have wrestled with the question over the years, we have slowly begun to realise it is more than an abstraction, the intangible concept embodying anything that can be expressed in strings of 1s and 0s. Information is a real, physical thing that seems to play a part in everything from how machines work to how living creatures function. Recently came the most startling demonstration yet: a tiny machine powered purely by information, which chilled metal through the power of its knowledge. This seemingly magical device could put us on the road to new, more efficient nanoscale machines, a better understanding of the workings of life, and a more complete picture of perhaps our most fundamental theory of the physical world. For at its heart, information is a mystery bound up with thermodynamics. This set of iron rules explains how heat is converted to and from other forms of energy, and governs a huge variety of processes. Thermodynamics makes a vital distinction between heat – a melee of random motions of atoms and molecules – and work, energy directed towards a purpose, such as the action of an engine pushing a car along. Perhaps the most cast-iron of the thermodynamic rules is the second law, which 28 | NewScientist | 14 May 2016

says that heat will not flow from a cool object to a warmer one unless you put in some work. Otherwise we could exploit this heat flow to do work and produce a perpetual motion machine. But is it so cut and dried? The idea that there could be exceptions to the second law dates from 1867, when James Clerk Maxwell concocted a thought experiment. He imagined a “very intelligent and exceedingly

“Heat flowing without work being done? That’s a brazen violation of physical law” quick” entity able to see the motions of air molecules. Given a box of hot air and another of cold air connected by a frictionless door, it could use this knowledge alone to allow fast moving molecules to pass one way and slower ones the other, making the hot box hotter and the cold box colder. Heat would flow without work being done – a brazen violation of the second law (see diagram, page 30). This being soon came to be known as Maxwell’s demon, an apt name because it presents us with a hellish problem. Thermodynamics is a monumentally robust theory, surviving intact even after many ideas were swept aside by quantum theory and relativity in the 20th century. Yet the demon demands an explanation thermodynamics can’t supply. Something was missing. A clue to what that might be came when

physicist Leo Szilard imagined a pared-down version of the demon in 1929. In this scenario, a single molecule is trapped in a box, and the demon can see which end the molecule is in at any given moment. The demon slides a partition into the middle of the box and lets the bouncing molecule push it up to one end, against a little resistance. That means it is doing work. The demon’s knowledge amounts to one bit of information, equivalent to a 0 or 1, and Szilard worked out how much work the demon can extract with its one bit. At room temperature it turns out to be about 3 x 10-21 joules of work, or enough to lift a bacterium about a nanometre. It was a hint that information might be the missing piece of thermodynamics. Others realised that the demon’s trick depends on its knowledge of the molecules but Szilard’s breakthrough was to quantify the information the demon needed. In 1961, Rolf Landauer, a researcher at IBM in New York, took things further, showing that erasing a computer’s memory requires work. His colleague Charles Bennett applied this result to the demon, reasoning its knowledge must be stored in some sort of finite memory that would sooner or later have to be erased for it to keep running. He calculated that the demon would have to expend at least as much work on this task as can be gained from the boxes of gas it is meddling with. Accounting for the cost of deleting information restored some balance to the demon’s thermodynamic world, but it was a little unsatisfactory. The demon still gets >

‘NO SHADOW’ BY MAKOTO TOJIKI

14 May 2016 | NewScientist | 29

Maxwell’s demon This is a thought experiment involving a “being” that can see the motion of the gas particles in two boxes. The faster the particles move, the hotter the box

Hot

Cold

If there is a frictionless door connecting the boxes, the demon can open it to allow the relatively fast molecules from a cold box into a hot box

The hot box gets hotter without the demon doing any work — a lagrant violation of thermodynamics Hotter

Colder

30 | NewScientist | 14 May 2016

blank memory could simply be a paper tape bearing a long string of zeros, although to do anything meaningful you would need a lot of them: 300 billion billion zeros allow the demon to lift an apple by 1 metre. Such a bizarre idea demands proper testing. And that meant summoning a real demon, a feat that’s proved difficult. Maxwell’s original thought experiment involved a demon with a complex mind, with inner depths that are impossible to fathom. That is no good for a physics experiment. In 2010, Shoichi Toyabe then as at Chuo University in Tokyo and his colleagues built a working demon using a tiny

“The demon can bend the second law for a while until its head gets too full” plastic rotor, a camera and a computer. This was a step away from human-like intelligence, but it still involved large-scale paraphernalia, so it was impossible to show exactly what was happening inside the demon. Better would be a very small and simple demon – really more of an imp – in which the flows of heat, work and information could be clearly traced. That’s just what was conjured up in Finland last year. Jukka Pekola and his team at Aalto University in Espoo created a microscopic demon of chilling and powerful simplicity. Their set-up, originally suggested by Massimiliano Esposito at the University of Luxembourg and his colleagues, is based on two quantum dots, devices that can briefly trap single electrons. One is known as the system, the other is the demon. The demon usually holds an electron, loosely. When an electron reaches the system, it repels and ejects the demon’s electron electrostatically. This process robs the system electron of some potential energy, which means that when it leaves the quantum dot it must use up some of its thermal energy to do so. The result is that it arrives in the wires cooler than when it left (see diagram, right). Once unleashed, this unholy set-up works fast. Within a second millions of chilled electrons arrive in the wires, reducing their temperature by about one-thousandth of a kelvin. Meanwhile, the demon’s temperature rises. “It is challenging to get everything to work,” says Pekola. “But as soon as the demon is tuned to the right position you don’t have to do anything: it is autonomous.” Crucially, the demon electron is on such a hair trigger that the electrostatic repulsion forcing it to leave is doing essentially no work, certainly not enough to lower the other electron’s energy by the extent seen. With no work being done, how can the system cool while the demon gets hotter? The

‘NO SHADOW’ BY MAKOTO TOJIKI

away with bending the second law for a while – until its head gets too full. And there our understanding stuck, until a flurry of new insights emerged over the past decade. A crucial result came in 2008, from Takahiro Sagawa and Masahito Ueda at the Tokyo Institute of Technology. They worked out that you can salvage the second law by adding an extra term called mutual information (Physical Review Letters, vol 100, p 080403). This is a measure of how much the demon knows about whatever system it is looking at. “You can think of the measurement as a correlation between the system and an apparatus or memory,” says Juan Parrondo, who studies the thermodynamics of information at the Complutense University of Madrid, Spain. Sagawa and Ueda’s updated second law shows how much work you can extract from a system for a given amount of demonic knowledge. It doesn’t hold only when memory is erased. “You can apply it to more general situations,” says Parrondo. “The consequences are quite peculiar.” One consequence is that blank memory can be a kind of fuel, an idea described in 2012 by Chris Jarzynski and Dibyendu Mandal at the University of Maryland, College Park. If Maxwell’s demon receives new empty memory, it can write information to it and do useful work as a consequence – Jarzynski and Mandal’s example is lifting a weight. That

feat seems impossible until we incorporate Sagawa and Ueda’s mutual information. Pekola’s team have shown that the cooling works exactly as predicted if mutual information is balancing the books. “It is exchanging information that results in a change in temperature,” says Sebastian Deffner at the Los Alamos National Laboratory in New Mexico.

Energy catalyst If information alone can have a physical effect, then it is a physical thing. So what kind of thing is it? There are two ways of looking at it. One is to consider information as a form of entropy, the quantity in thermodynamics that expresses disorder. In Maxwell’s thought experiment, that equates to how mixed up the molecules are. The more disordered they are, the more information the demon must have to do its job. Another way to think of information is as a kind of energy catalyst: it enables you to convert the chaotic energy of heat to the useful energy of work. So when people say information is power, they’re not far wrong. Yet this is hardly the last word on the nature of information. For one thing, although Pekola’s demon involves single electrons, they are constrained to behave mostly like classical particles that don’t exhibit the strangest features of the quantum world. Quantum

cost of repeatedly wiping its memory, which requires work. But demons can still perform special tasks for us. “They could be useful to move heat somewhere that is not so critical in your circuit,” says Pekola. In other words, demons could act as local refrigerators in nanoelectronics, especially important for the powerful quantum computers of the future.

Meet your demon

particles can show superposition, being in two places simultaneously. And two or more particles can be entangled, correlated with one another in such a way that measuring one affects the properties of the other. “In quantum systems the situation is much more complicated,” says Deffner. “Some energy and some information is encoded in the correlations but we have to better understand where to put this in the equations.” Pekola plans to create a truly quantum demon, one that operates on qubits, the quantum mechanical equivalent of a bit, which can be both 0 and 1 simultaneously.

The most likely option is to make one out of a superconducting electronic circuit, which would emit a single photon when it changes state. To peer into the mind of the quantum demon he will need a new type of singlephoton detector, which several teams around the world are working towards. But now we’re arming ourselves with a firmer understanding of information, what does it all mean? Well, Pekola’s demon is not going to bring us perpetual motion. It is still governed by the restrictions Landauer hit upon: it can create a temperature difference that could be used to do work, but only at the

The real deal A new experiment creates a version of Maxwell’s demon that chills a wire without requiring work, an apparent violation of thermodynamics 1

A device has two quantum dots that can hold one electron each. To begin with, only one dot is illed

2

WIRES

An electron lowing into the empty dot repels the other electron, expelling it from its dot ELECTROSTATIC REPULSION

3

This involves almost zero work, yet the loss of the repulsive force lowers the potential energy of the irst electron

4

The electron eventually lows away, but it can only do this by using up thermal energy. This cools the wire

These ideas could also have implications for our understanding of biology. “Organisms sensing their environment have to expend energy, with fundamental limitations based on information,” says Jordan Horowitz at the Massachusetts Institute of Technology. And according to the mutualinformation tweak of the second law, acquiring information requires a minimum energy outlay. By studying how E. coli bacteria sense the concentration of certain chemicals, Horowitz and his colleagues worked out that they use only about twice the theoretical minimum. So maybe the fundamental cost of processing information is a significant burden cells have had to learn to cope with. Like bacteria, humans are on one level information-processing machines, so did the fundamental cost of information processing shape us? Parrondo has analysed the proofreading process in DNA transcription, where enzymes pause, go back and cut out erroneously placed base pairs. He concluded that this activity is designed to optimise a three-way trade-off between speed, accuracy and energy use. The situation is more complex than Maxwell’s demon, and the maths he used is different. So it’s not yet clear whether the fundamental energy requirements of processing information really have affected the evolution of error-checking. “We would like to have the same framework for all types of problem. We don’t have it yet,” says Parrondo. Some even think there may be demons within us. Kinesins are motor proteins that clamber around our cells, transporting other proteins and whatnot. According to Martin Bier at East Carolina University in Greenville, North Carolina, kinesins may use a form of position-sensing feedback, akin to Maxwell’s demon, to move more efficiently. Parrondo is not convinced, however. “This is very speculative,” he says. There’s more to learn about the role demons might play inside us or the computer minds of the future. But one of their kind has already opened the door of knowledge, just a crack, to reveal a glimpse of information’s true nature. ■ Stephen Battersby is a consultant for New Scientist 14 May 2016 | NewScientist | 31

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Empathy is a healthy emotion – but could there be too much of a good thing, asks Emma Young

I feel your pain

SIMON PRADES

T

ANIA SINGER wasn’t the first person to put a Buddhist monk in an fMRI machine. But the neuroscientists who had scanned supposedly caring, sharing brains before did it to find out where empathy comes from. Singer was looking for ways to avoid it. Few people would argue that the world is cursed with an excess of empathy. But we are starting to discover that our capacity to share other’s emotions and take their perspective comes with a sting in its tail. Overdosing on the misfortunes of others is not just a problem for those in high-exposure professions such as nursing. All of us are vulnerable to catching the pain of others, making us angrier, unhappier, and possibly even sicker. Fortunately, work on locating the root of empathy in the brain has also led to the discovery that with the right training, we might be able to tune how much we let others’ emotions affect us. This could allow us the best of both worlds – to care, without letting it consume us. Empathy is undeniably a good thing. Understanding how others are feeling is a bonding mechanism that we are finding in an increasing number of animals, including dolphins and rats. In humans, primatologist Frans de Waal of Emory University in Atlanta, Georgia, has suggested that being affected by another’s emotional state was the earliest step in our evolution as a collaborative species. But the pitfalls will be apparent to anyone who has been in a room full of babies. If one starts crying, pretty soon, they’re all at it. Babies don’t understand the difference between their own emotions and those being felt by others, and so what one feels, they all

feel. Negative and positive emotions alike spread like a virus. As our sense of self develops, we learn to distinguish other people’s emotions from our own, although a variety of experiments, most recently studying our behaviour in online social networks, indicate we are not entirely free of the risk of emotional contagion (see “Socially contagious”, below). That’s because the distinction between what we and others feel isn’t terribly clear to our brains. Singer, then at University College London (UCL), and her colleagues demonstrated this in 2004 when they put

SOCIALLY CONTAGIOUS Social networks such as Facebook and Twitter provide for many of us a very public window on our emotions – and seem to indicate just how sensitive those emotions are to outside influence. In 2014 Facebook caused a furore when the company revealed it had secretly been experimenting with the feelings of half a million users. By tweaking the algorithms that determine whether the stories people see are more positive or negative in tenor, the researchers claimed they had shown that emotional states could be transferred via social network. In September 2015, researchers at the University of Southern California followed up with their own study on Twitter, demonstrating increases in negative posts after people saw a Twitter timeline that had been tweaked to be more negative than usual.

16 romantic couples into an MRI scanner. When they gave the volunteers a painful electrical shock, this elicited activity in brain regions known to respond to physical pain and also in regions tuned to emotional pain. But when volunteers saw their loved one get a shock, no activity registered in their physical pain centres – while the emotion regions lit up like fireworks. Notable among these was the anterior insula, where a lot of the coordination between brain and body takes place. Since then, many other studies have confirmed that this “empathy for pain” network exists, and that it doesn’t distinguish whether the pain you’re observing is physical or psychological. “The basic principle is the same,” says Singer, who is now at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany. What’s more, over the past few years it has become apparent that we don’t just catch pain from those we are intimate with. The first hints came from people in care-giving professions who often see the stress and pain of others, such as hospice staff, nurses, psychotherapists and paediatricians. Since the early 1990s, a kind of empathy burnout has increasingly been documented – given names including “secondary traumatic stress” and “vicarious traumatisation”. Symptoms include lowered ability to feel empathy and sympathy, increased anger and anxiety, and more absenteeism (see “The hurt locker”, page 34). Various studies link these symptoms with an indifferent attitude to patients, depersonalisation and poorer care. It’s perhaps unsurprising that empathy burnout can affect people frequently > 14 May 2016 | NewScientist | 33

“Empathy, once a benefit, may become a liability in an anonymous, crowded modern world”

34 | NewScientist | 14 May 2016

One location this is likely to happen is the workplace: we spend 8 or 9 hours a day with our colleagues, creating relationships that help us empathise with and catch their distress. Recently some companies, such as Ochsner Health System, which owns and operates hospitals and clinics in Louisiana, have begun to institute stress-free zones to limit contagion. “Venting is not productive,” says Missy Hopson Sparks, a vice-president at Ochsner. So the company designated zones, including hospital floors, where sharp conversations, even whispered, were off limits. Morale in clinics rose. The policy is now company-wide. Singer’s research indicates that for some people the physical effects of emotional contagion apply even when they observe a person they don’t know suffering distress (see “Stranger danger”, left). That is backed up by experiments in which, for example, people who watched a 15-minute TV newscast reported increased anxiety afterwards, with their anxiety only decreasing after an extended relaxation exercise. For those less prone to experiencing “empathic distress”, it might be tempting to dismiss it as someone else’s problem. That’s shortsighted, says Olga Klimecki at the University of Geneva in Switzerland. People who experience more empathic distress in their daily lives are more likely to become aggressive when provoked, “even towards an innocent person”, she says. That’s backed up by work published by Michael Poulin at the State University of New York at Buffalo published research last year, indicating that empathy can lead us to act aggressively, specifically when we see someone we value being mistreated. “Experiencing a suffering person’s distress as if it were your own is highly aversive and unpleasant,” he says. The irony is that the effects of empathy overload might undercut the very things for which empathy evolved in us – mutually beneficial cooperation and collaboration. “Even in the short-term distress transmitted via empathy leads just as much to a desire to escape a helping situation as it does to a desire

The hurt locker Some jobs give you a much higher chance of getting ill because of work-related stress, anxiety and depression than others, in part because of how frequently you witness the pain of others 3000

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5-minute speech, and once that’s done, you are quizzed for 5 minutes on increasingly difficult arithmetic. All the while, the judges watch impassively. For most people, the test results in a flood of the stress hormone cortisol, clammy hands and a rapid heartbeat. In Singer’s experiment as one member of each pair was tested, their partner merely watched, either through a one-way mirror, or via a television. To remove any fear that the observer would be tested next, they had written guarantees that they wouldn’t go through it themselves. Even so, some 10 per cent of volunteers experienced cortisol flooding simply from watching the stranger’s stress – even when that stress was merely on a screen. “To find such a significant hormonal response in someone who is merely passively observing another person getting stressed on TV, even when it was a stranger, was quite a surprise,” says Singer.

Empathy overload

to help,” says Poulin. Empathy, so beneficial when we lived as hunter-gatherers, can be a liability in a modern world characterised by anonymous, crowded cities and emotionladen media content. If that’s true, can we do anything about it? Perhaps, says Christian Keysers of the Netherlands Institute for Neuroscience in Amsterdam. “Just like some people are better at regulating their own emotions, some are better at regulating empathy,” he says. His work suggests we’re not stuck with the amount of empathy we are born with, but can adopt the strategies of others. In 2014, Keysers and his colleagues looked at how people diagnosed with psychopathy, who are commonly thought to lack all capacity for empathy, react when they see images of people in pain. At first, the team presented images without any instructions as to what to feel. The volunteers’ brains showed, predictably, less activity in areas associated with empathy for sensations, and in the insula, than the brains of healthy people. But then Keysers asked his psychopathic volunteers to consciously empathise, and something very different happened: their brain responses were identical to the control

People in UK signed off sick per 100,000

How much do you have to care about someone to be infected by their stress? For some of us, not very much. That at least is the conclusion of Tania Singer at the Max Planck Institute for Human Cognitive and Brain Studies in Leipzig, Germany. She paired volunteers either with a loved one or a stranger and subjected one member of each pair to the Trier social stress test, a standard protocol to induce stress. In front of a panel of judges, you get 3 minutes to prepare a

surrounded by other people’s pain. But a recent spate of experiments suggests that the dark side of empathy spells trouble for everyone. You can “catch” stress any time you understand someone else’s pain and share in it, activating your empathy for pain network.

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STRANGER DANGER

ASHLEY GILBERTSON / VII

Stress can be contagious even if we feel it remotely

group’s (Trends in Cognitive Science, vol 18, p 163). In other words, even if your default empathy state is “off”, you can turn it on when desired. That was an eye-opener, says Keysers: it seemed clear that a spectrum of empathy could exist in all individuals. Hence why Tania Singer found herself putting Matthieu Ricard, a molecular biologist turned Buddhist monk, into an fMRI machine. Experiments have shown that the training Buddhists monks undergo give them a heightened ability to manipulate their neural circuitry of empathy. One of the first such studies was done by Richard Davidson at the University of Wisconsin, Madison. Monk volunteers were asked to lie in fMRI machines as they heard sounds such as women screaming in pain. As they listened, Davidson asked them to engage in a form of compassion meditation known as loving kindness meditation, in which you are encouraged to gradually extend warmth and care out from yourself to others. Davidson found that this process changed the firing of the monks’ neural circuitry. It suppressed activity in the anterior insula, the brain region implicated in Singer’s earlier experiments on empathy, and also in the amygdala, a region involved

in threat detection but recruited during empathic responses. In her latest experiments with Ricard, Singer asked him to empathise with suffering instead of engaging in compassion as he had been trained to do. When she did so, his empathy for pain network lit up, and almost immediately, he begged her to stop the experiment, calling the feeling “unbearable”.

Your inner psycho This hints that looking on other people with compassion rather than empathy might be a way to sharpen the distinction between you and someone else and avoid empathy burnout. “Compassion is feeling for and not with the other,” says Ricard. With Klimecki and others, Singer has started to test the idea on regular people. After putting subjects through compassion training, their brains responded to negative videos much like the monks’ brains (Social Cognitive and Affective Neuroscience, vol 9, p 873). This was reflected in increased well-being. Singer’s work in this area is fascinating, says Antonia Hamilton at the Institute of Cognitive Neuroscience at UCL, “especially

the distinction between compassion and empathy”. Recently, Singer and her team completed the first major project that turned this research into practice. Her group recruited 300 people, some whose jobs put them at higher risk of empathy burnout, and trained them in alternatives to empathy, including compassion. One participant was Irina Schroen, a nurse in the neonatal unit at the Charité University Clinic in Berlin, Germany, whose experiences had come to affect her so severely that she was ready to give up her career. Singer’s training, she says, saved her professional life. “My colleagues are once again happy to work with me,” she says. “They say, ‘It’s incredible how relaxed you are now’.” The results will not be published until later this year, but they were impressive enough that Singer is now setting up a centre to deliver this kind of training to anyone, and 60 people are already signed up. She hopes it will pull more people like Schroen back from the brink of burnout, and more broadly help people and communities deal with social conflict – including problems resulting from war and the arrival of refugees. Others in high-stress, high-performance professions might benefit from sliding more towards the “psychopath” end of the scale, says Del Paulhus, who studies personality traits at the University of British Columbia in Canada. “Too much empathy would undermine success as a surgeon, an athlete in violent sports, a lawyer, soldier,” he says. It’s a point worth bearing in mind now that empathy is firmly on the political agenda. US president Barack Obama has identified an “empathy deficit” as a pressing problem. How to increase it is a hot topic; a recent study by Stanford University researchers appeared to link empathy training for teachers with fewer disciplinary problems in students. Education researchers and business leaders in the US and the UK have called for empathy to be taught in schools. Appropriately dosed, empathy is undoubtedly a good thing, but we need to consider the side effects before we start prescribing it wholesale. “It’s not at all clear the world needs more empathy if that means experiencing another person’s suffering as your own,” says Poulin. “Doing that may simply double the world’s suffering”. ■ Emma Young is a writer in Sheffield, UK 14 May 2016 | NewScientist | 35

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Dead giveaway Max Green digs out the 10 best gravesites to ind out what they reveal about our evolution

36 | NewScientist | 14 May 2016

N

O OTHER animal buries its dead. It is a peculiarly human thing to do, and we’ve been doing it for a long time. Last year, it emerged that our ancestors may have laid their dead to rest as far back as 3 million years ago. This raises intriguing questions about the evolution of the human mind. To understand the idea of death, you need empathy and intuition. To feel your own mortality and to create rituals that recognise the mortality of others, you must be capable of symbolic thinking – which also underpins language, art and religion. What’s more, burials reflect the cultural concerns and practices of the people who created them. Graves, therefore, hold clues about human curiosity, the dawning of spirituality, ancestor cults, global domination, trade, technological ingenuity and more. In search of these, we’ve unearthed 10 of the most significant gravesites:

but if Sima del los Huesos and Rising Star cave are gravesites, that would make them among the most exciting ever discovered. 160,000 YEARS AGO

CURIOUS SKULLS Three skulls unearthed in Herto Bouri, Ethiopia, in 1997 hint at an early interest in meddling with the remains of the dead. The skulls, from two adults and a 7-year-old child, belong to a subspecies of Homo sapiens that lived nearly 160,000 years ago. There are no other hominin fossils nearby, suggesting that they were carried there from some distance. And they were manipulated before burial. Both adult skulls have a series of scratches etched into them. Whoever did this probably worked with a razor-sharp obsidian flake, using it to separate skin and tissue from bone. The child’s skull appears to have received special attention: it has deep incisions at its base that don’t appear on the adult bones; portions of the cranium were polished with great care; and the lower jaw has been removed. Cut marks and polishing on bones are hallmarks of cannibalism, which was surprisingly common among various populations of our ancestors. Had this been the fate of the Herto three, however, their skulls would have been smashed open, not handled with such care. The transportation, precise defleshing, carving and polishing suggest that whoever was responsible attached a sense of meaning or symbolism to their actions. If nothing else, the state of the remains indicates that our ancestors, even before they were fully human, had an innate curiosity about the dead. >

2-3 MILLION YEARS AGO

THE FIRST BURIALS?

Not cannibalism, but what do the cut marks on this skull signify?

(C) 2001 DAVID L. BRILL, HUMANORIGINSPHOTOS.COM

The ancient remains discovered deep inside the Rising Star cave in South Africa were in a place so inaccessible that petite climbers had to be hired to get them out. Last year, the bones were identified as belonging to a previously unknown species of human, Homo naledi, dating from between 2 and 3 million years ago. But how and why they ended up in such an inaccessible cave system remains a mystery. One idea is that they were laid there after death. If so, the first burials were much earlier than we thought. Until Rising Star, the best contender for the oldest gravesite was the Sima de los Huesos, or “pit of bones”, in Spain. It lies at the end of a steep 13-metre shaft in a system of caves in the Atapuerca Mountains. It contains a treasure trove of remains of members of the human family – hominins – dating from between 450,000 and 400,000 year ago, which new research shows to be from early Neanderthals. The presence of some 30 individuals suggests they didn’t get there by accident. Then there’s “Excalibur”, a biface Acheulean hand axe made of red quartzite, found alongside the fossils, which has been interpreted as a graveside offering. Even the idea that our ancestors were burying their dead 400,000 years ago is contentious. It is not only a sign of early intelligence but of a capacity to think symbolically. And it implies an awareness of the self that separates our ancestors from other animals. We’ll probably never know for sure when these giant cognitive leaps occurred –

14 May 2016 | NewScientist | 37

X marks the spots These 10 key burial sites hint at when, where and how our minds and culture have evolved

120,000 YEARS AGO

Germ warfare

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RED IS FOR RITUAL The irst burials?

Humans living in what is now Israel up to 120,000 years ago may not have had language, but they were no strangers to symbolism. Graves found at Skhul, near Lower Galilee, contained 10 individuals, some with their arms folded across their chests and legs bent. Others were buried with grave goods including seashells fashioned into beads. One man lay on his back with the mandible of a wild boar wrapped in his arms. Another clutched the skull of a bovid. A nearby gravesite at Qafzeh, on the slopes of Mount Carmel, also contains strong evidence for the emergence of symbolic thought. Here, 90,000 years ago, a small boy was buried with the antlers of a fallow deer resting across his neck and his hand propped up on the deer’s skull by his side. Another grave contained a young adult, thought to be female, with an infant lying across her legs. Archaeologists excavating the graves at Qafzeh have found 71 pieces of red ochre – a clay pigment associated with a variety of Palaeolithic ritualistic practices. The Skhul graves also contain ochre, some of which seems to have been heated to obtain a specific red hue. The careful arrangement of remains suggests intentional burial, but cannot by itself be interpreted as signifying symbolic thought, says Erella Hovers at the Hebrew University of Jerusalem, who was involved in the Qafzeh and Skhul excavations. “But the presence of grave goods would definitely support this view.” Add the red ochre, with its ritualistic connotations, and this indicates that, for these people, death and burial were infused with meaning and symbolism.

Spain 450,00

Red is for ritual Israel 120,000 years ago

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9000 years ago

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Michael Walker of the University of Murcia, who is part of the excavation team, thinks the cadavers were placed in the cave for protection. He suggests it may have been a practical decision. Perhaps whoever put them there was worried the bodies would attract predators, or was simply put off by the smell of decay, he says. “It may have just been good housekeeping.” However, others see the burials as evidence that Neanderthals, like early humans, were capable of symbolic thinking. Near the bodies were flake tools and artefacts made of limestone, quartzite and rock crystal, some of which must have been fashioned 25 kilometres away. There are also several severed panther paws. If the paws and other Palaeolithic artefacts held a special meaning for those Neanderthals, it seems unlikely that they were simply tidying up their dead. 15,000 YEARS AGO

Once humans adopted a sedentary lifestyle, the practice of burying the dead seems to have flourished. This particular grave, found in the Hilazon Tachtit cave site in northern Israel, exhibits several characteristics that would later become common behaviour in funerary practices worldwide. An elderly woman was buried with a basalt bowl, which suggests there was a graveside ritual, and turtle bones found nearby look like the remains of a funeral feast. But other grave goods indicate something more extraordinary. There are 50 tortoise shells, bones from various animals including a cow, a leopard and an eagle – and an extra human foot. “We interpret it as a shaman burial,” says Leore Grosman at the Hebrew University of Jerusalem, who excavated the Hilazon cave. “[If so] it means that by this point in time the Natufian needed a spiritual leader to help them deal with the kinds of cultural stresses they were going through.”

GETTING SPIRITUAL 43,000 YEARS AGO

A STACK OF BONES A century ago, a team of iron ore miners blasted a 20-metre-long tunnel into a hillside in Murcia, Spain, and came across a complex cavern now called Sima de las Palomas. They didn’t know it, but they may have been the first people there in 43,000 years. The site, although extensively damaged, has since yielded some intriguing Neanderthal remains, including three entire skeletons stacked one on top of the other and covered in rocks, which appear to have been placed deliberately. Two of them, a woman and a child, had their arms bent so that their hands rested against their foreheads. 38 | NewScientist | 14 May 2016

For most of prehistory, our ancestors were foraging nomads. We don’t know why they made the transition to become homesteading farmers, but we do know that it first occurred in a fertile area east of the Mediterranean. The Natufian people were among the pioneers. One of their burials, dating from between 15,000 and 11,500 years ago, holds clues about how they coped with the dramatic shift.

“The grave, containing 50 tortoise shells and an extra human foot, looks like a shaman burial”

12,600 YEARS AGO

AN ALL-AMERICAN BOY Exactly when and how humans colonised the Americas is hotly contested. The pioneers were probably Stone Age explorers who migrated from Asia about 16,000 years ago. Some went on to develop the Clovis culture renowned for its sophisticated tools, which have been found all over the western US. All that is known about Clovis burial practices can be traced to a single grave discovered in an underground cavern in Montana in 1968. It dates from around 12,600 years ago and contained the remains of a 3-year-old boy and an enormous cache of goods, including various flint and bone tools, covered in red ochre.

The direct ancestors of native Americans buried these tools

9000 YEARS AGO

AP PHOTO/MATT VOLZ

SLEEPING WITH THE DEAD

DR. FRANCESCO COSCHINO, DIVISIONE DI PALEOPATOLOGIA, UNIVERSITÀ DI PISA

“What the Clovis people left behind here were things that would have been important to them in terms of ritualistic significance and for their survival,” says Michael Waters of Texas A&M University in College Station. Most intriguing is an heirloom bone tool approximately 150 years old when it was buried, which he interprets as an “offering”. The size and significance of the cache suggest the Clovis boy was the son of someone special. “Whoever his parents were, their genetic material lives on,” Waters says. In 2014, the child became the earliest ancient American to have his genome sequenced. This showed that genes he carried are now found in most tribes in Central and South America and probably the US too. Nobody had expected one grave to reveal so much about the legacy of the Clovis people. “They’re the direct ancestors of basically everyone living south of Montana,” says Waters. “It’s an incredible thing to wrap your head around.”

Would you sleep soundly knowing that the remains of your loved ones lay just inches below your bed? That’s what the residents of Çatalhöyük did 9000 years ago. Occupants of what may have been the world’s first city, situated in modern Turkey, would place dead family members inside raised-earth platforms or in pits dug into the floor of their homes. Once tucked into their holes in a fetal position, a clay cap or reed mat was placed over the grave, which was then used as a bed. Sometimes, graves were reopened and additional bodies squeezed in. When the family moved house, they dug up the remains and took them too. Not all bodies were buried at home, though. Archaeologists have also found what look like shrines – one holding more than 60 skeletons in its floor. These buildings were often embellished with sculptures, murals and animal horns, and would have required significant upkeep. Caring for the dead, and keeping them close, seems to have been a central tenet of life and culture in Çatalhöyük. So much so, that it has been called an “ancestor cult”.

contain clues about their ingenuity. One burial mound at Utyevka in Russia is 100 metres long. Status weapons including a copper dagger and a cast copper shaft-hole axe signify it was the tomb of an elite warrior. The grave also contained a pestle, probably used for grinding food or pigments, and a pair of gold earrings. Yamnaya graves rarely contain gold and the earrings are particularly significant because the gold is made using an advanced technique called granulation.

“These were innovative people and their graves contain clues about their ingenuity” “These objects are indicators of foreign trade, long-distance communication with the Aegean civilisations of the era in the Middle East,” says David Anthony at Hartwick College in Oneonta, New York. The metalwork also shows the Yamnaya’s desire to innovate. “It’s very early in the evolution of metallurgy and they’re doing these weird experiments putting copper and iron together long before other people worked out how to,” he says.

5500 YEARS AGO

THE PAST 1000 YEARS

CULTURAL SMELTING POT

GERM WARFARE

A mysterious group of cattle herders, living on the Eurasian steppe some 5500 years ago, has recently emerged as one of the founders of Western civilisation. The Yamnaya spoke Proto-Indo-European – from which most modern European languages originate – rode horses, used wheels and traded widely. These were innovative people and their graves

If a grave can tell us a lot, what might we learn from a thousand-year-old cemetery? Monks began burying people in the Badia Pozzeveri churchyard in Altopascio, Italy, in the 11th century, and these human remains, together with records of climate and socio-economic conditions, provide a remarkable timeline of human health and disease. Of particular interest are the mass graves dating from the 1300s and 1800s, when the Black Death and then cholera struck the region. Along with human remains, researchers are finding microscopic remnants of the bacteria that caused these diseases. A team is now looking for DNA from the pathogens, which they will use to find out how they have changed over time, when they acquired resistance to drug treatments and which modern strains they most closely resemble. If the work is a success, these disease organisms may turn out to be more valuable than even the most precious grave goods. They will provide crucial information to help us fight future epidemics. ■

Buried encased in lime in the mid-1800s, this woman’s body may still contain traces of the cholera bacterium

Max Green is a science writer based in Chicago 14 May 2016 | NewScientist | 39

PEOPLE

The internet of unprotected things My search engine reveals every vulnerable device on the internet, from baby monitors to nuclear plants, but that’s not why I created it, says John Matherly

The internet is bigger than people think, isn’t it?

Why create such a search engine?

MOST EXPOSED

Many people think that the web is the internet. They see the Googles, the Facebooks, the Reddits… but the web is something built on top of the internet and so only the tip of the iceberg. The iceberg is composed of webcams, power plants, printers… billions of devices.

My original idea was to make a tool for market intelligence. I thought that I could use it to tell firms who was using their software and whether customers were regularly updating it, for example. Or I could tell them which countries prefer their product over a competitor’s. The idea was not about security.

Conservative estimates of insecure industrial control systems

As Shodan began to uncover online devices, which ones surprised you?

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When did this first strike you?

When I started out, I thought of the internet as very much a black box, but I always had the idea that it was huge. I didn’t think that I could actually survey everything connected to it, but I figured that nobody else was doing that so I could at least start collecting the data. It turned out you can crawl the whole internet, so I developed a tool to do that. And it was only when I released it as a search engine called Shodan that lots of people started finding non-websites: printers, databases, industrial control systems, cellphones, cars – a huge breadth of internet-accessible devices. How does Shodan work?

There are about 4 billion possible public addresses that a device could have on the internet. Shodan randomly picks an IP address, goes there and then asks if it is running software that can be accessed online. If the device responds and essentially says “yes I am”, Shodan notes that and moves on to the next random IP address. It’s a scattershot approach, but it can find everything connected to the internet in just a few hours.

40 | NewScientist | 14 May 2016

54,501 China

To me it was definitely the control systems. I come from a biology and computer science background and I really never imagined that anybody would find the system controlling a nuclear power plant on the internet, but there it was. It was taken offline very quickly after being discovered. There were also weird things like car washes and crematoria – I had no idea that these things had become so advanced. Can anyone connect to these systems and meddle with them?

No. There’s a big difference between being able to connect and being able to cause damage – that’s only usually possible if you have a good understanding of how they operate. If you don’t work with control systems for, say, big turbines, you probably don’t know how these things work. Still, there’s no good justification for having power plants accessible like this in the first place. Why is such critical infrastructure online at all?

PROFILE John Matherly is a Texas-based software engineer and the creator of Shodan, a search engine launched in 2009 for the internet of things

US

Let’s say you run a wind farm with many wind turbines. If you want to fix a software bug, you don’t want to send a technician to every location. That is a complete nightmare, and

Canada

6498 Italy

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expensive. Being able to access the turbines over the internet is an obvious solution. Still, why would they be so openly accessible?

These control systems often don’t have any authentication. The software they run is usually proprietary and very often was designed 15 to 20 years ago. As such, it doesn’t include user authentication or security because it was only designed to be accessible locally. When you see such systems on the internet, it often means you have complete administrative access.

At least now there’s a way for the good guys to get some visibility into the internet too. Does the growing internet of things worry you?

I’m concerned about the direction that it is taking, because security in general is an afterthought. Everything from smart TVs to lawn sprinklers and light bulbs are all getting connected and controlled via the internet. And people often don’t appreciate that these devices now contain full-on computers – they aren’t dumb any more. How are you going to deal with infectious malware inside your light bulbs? Another danger is criticality in numbers. If you can only compromise a few hundred smart refrigerators, it’s probably not a big deal. But what if you can compromise all the refrigerators on a continent? Or all the airconditioning units in Texas during summer? These are devices that we don’t tend to replace for a long time and if you don’t get the security right early on, fixing it later is very difficult. Is the public is aware of the vulnerability of their gadgets?

To some extent. Earlier this year the Ars Technica website published a story on how webcams have terrible security – it made a reference to hackers watching other people’s sleeping babies. Understandably, it elicited a very emotional response. You can find webcams that are accessible using Shodan, but it’s worth noting that there are fewer than 10,000 of them, the majority being cheap knock-offs bought from China.

PHOTOGRAPHED FOR NEW SCIENTIST BY JEFF WILSON

How can everyday users protect themselves?

Have you ever called someone up in the middle of the night to warn them that something important was online?

There have been a few instances. I’ve found some large databases full of personal user information exposed, for example. But I don’t usually call the companies who are responsible: they may shoot the messenger. I go to government agencies whose sole objective is to react to computer intrusion – any sort of dangerous or malicious activity. You can report vulnerabilities to them and they will follow up with the organisation.

Could hackers use Shodan maliciously?

In many ways, Google is a tool that you could use for malicious purposes. At the end of the day Shodan is a tool too – a different type, for a different audience. We take as many steps as we can to limit abuse. For example, we don’t let users download the whole data set unless we have an enterprise agreement with their company. And we take steps to prevent people accessing Shodan anonymously. But even before Shodan there were ways for people to find such information – using malware, for example.

The simplest lesson is, if you can access your device over the internet with your smartphone or computer, make sure it has authentication/passwords enabled. If it doesn’t, the chances are anybody else on the internet can also access it. The second lesson is to buy products that automatically update their own software. Do you think we’ll see more serious cyberattacks on connected devices in future?

I’d be surprised if we didn’t. Just looking at some of the key products being released today, anything outside of smartphones, PCs and servers have poorer security than people might expect, and some have very serious security problems. Then there are industrial control systems. People assume that they have many layers of security, yet the majority of industrial protocols don’t even have the capacity for authentication, meaning the software doesn’t even support setting a password. These are mistakes that we just shouldn’t be making any more, which is why I suspect the problem will get exponentially bigger. ■ Interview by Chris Baraniuk 14 May 2016 | NewScientist | 41

Welcome to New Scientist Live, a four-day festival of ideas and discovery. Here, you’ll find the best, latest and most provocative science, guaranteed to touch all aspects of human life

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WHERE Excel London WHEN 22 – 25 September 2016 WHAT Talks, debates, exhibits, demonstrations. Interact with the latest technology and engage with 100 of the world’s most original thinkers

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CITY TRAVEL GETS A LIFT One vision of future road transport in our towns and cities does away completely with private cars in favour of self-driving, electric vehicles for hire. Such a shift should cut traffic congestion, pollution and accidents while giving added freedom to the young, old and anyone who doesn’t drive. For the plan to work, the vehicles would have to go everywhere, including pavements and shopping centres. Enter the LUTZ Pathfinders, self-driving “pods” that are roaming pedestrianised areas of Milton Keynes to test the feasibility of this idea. They are loaded with sensors – including stereo cameras, laser scanners and radar – and computers capable of reacting to the data and plotting a course. For now, the pods are being driven by humans while the sensors build a map of the

environment. But the computers are set to take over. The trial, overseen by the Transport Systems Catapult, has started with three pods but the aim is to expand this to 40 as part of the UK Autodrive project. Innovate UK, the national innovation agency, will be hosting the LUTZ Pathfinder at New Scientist Live along with several other nascent technologies. Come glimpse the future!

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Freya Harrison

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A potent weapon in the fight against superbugs has been found in, of all places, a 9th-century Anglo-Saxon text (pictured above). All that’s needed is some garlic, wine and a soupçon of cow’s bile. Microbiologist Freya Harrison from the University of Warwick, discusses the remedy, its discovery and the work of Ancientbiotics, a group of researchers scouring ancient texts to see what lessons we can learn for modern medicine.

If civilisation vanished tomorrow, how would you cope? Would you even know where to start in rebuilding our world? Astrobiologist Lewis Dartnell from the University of Leicester has studied everything from making fire and drugs to purifying water, restarting agriculture and generating power. Discover the must-know information to survive the apocalypse as he reveals the principles that have underpinned society for centuries.

As climate change takes hold, the need for clean energy has never been greater. Meet Steve Cowley, who wants to harness fusion – the process that powers the sun – down here on Earth. He heads the Culham Centre for Fusion Energy near Oxford, which is spearheading efforts to harness fusion as a large-scale energy source. Hear about the latest advances and find out when fusion energy will be appearing at an electricity socket near you.

They are the biggest questions in science: where did the universe come from and how will it all end? David Tong, theoretical physicist at the University of Cambridge, tries to answer these questions for a living. Join him on a multi-billion-year journey from the unparalleled cataclysm of the big bang to the eventual fate of the cosmos.

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CULTURE

The shadows on the wall Watching a great mind decode cave art is a rare joy, finds Steven Mithen

JEAN CLOTTES has been looking at and thinking about the cave paintings of ice age Europe for almost half a century. I can’t imagine anyone has a greater knowledge about the paintings, carvings, sculptures and their associated archaeology than this great prehistorian. It’s not just greater knowledge, but an emotional response: I’ve seen tears come into his eyes as he was describing a painting that he must have seen and talked about many times before, and that still tugged at his heart as much as his brain. Clottes’s enormous depth of learning and affection emanate from every page of this book, originally published as Pourquoi l’art préhistorique? The presumably deliberate mistranslation of the French title by the publishers into What is Paleolithic Art? is misleading to the reader and does Clottes a disservice. Within the first few pages Clottes is quite clear that his intention is to address the “why” not the “what” about cave art. Indeed, the book assumes that the reader already has a grasp of what the art is about. Without any preliminary description of the art, Clottes immediately steps into the 44 | NewScientist | 14 May 2016

multitude of interpretations that have been proposed since the first engraved objects were discovered 150 years ago. He does so partly because he is adamant that there can be no description untouched by theory: what one believes influences what one sees, whether on the cave wall or in the ground. Clottes swiftly takes the reader through the many ways of interpreting and decoding the art. There’s the art for art’s sake idea, the totemic, hunting, fertility, sympathetic or destructive magic approaches, and the structuralist one. His favourite is the shamanic theory, one that he eventually shows to embrace elements of all the other interpretations. After reflecting on the risks and contributions of ethnography – the study of peoples and customs from the point of view of those being studied – Clottes leads us on a journey to rock art sites in the Americas, Australia, Africa and Asia. This embraces not just the art but also the indigenous people

A single theory may explain fertility images (below) and bison (above)

JEAN CLOTTES

What is Paleolithic Art? Cave paintings and the dawn of human creativity by Jean Clottes, translated by Oliver Y. Martin and Robert D. Martin, University of Chicago Press, $18

who maintain the traditional knowledge about and ways of behaving around it. Emphasising the need to see the art first-hand and in its landscape setting, Clottes recounts his own journeys to the sites and his encounters, surprises and shocks en route. We follow as he develops his understanding, not just about the rock art but about the commonalities of the mindset of the hunter-gatherers who create it. He finishes this journey with the lovely understatement that his “rich and multiple experiences had a far from negligible influence” on his way of thinking about ice age art in Europe. Then, about midway, Clottes’s book takes us to his home territory – the caves of France and Spain – to look at the paintings through the mindset of a huntergatherer. That mindset, he argues, has four major components that cannot be easily separated: the “interconnection of species”; the “fluidity of the living world” (animals can transform into humans and vice versa); the

unequivocal acceptance of the “complexity” of the world (for example, the Sami have 600 words relating to reindeer, referring to a particular age, sex, colour, antlers, fur and so on); and “permeability”, the constant intervention of spirits and supernatural forces in the world. It is this mindset, so very different from Western mindsets but traces of which, he claims, can be found across the globe with specific cultural variations, that will allow us to better understand the people of the Palaeolithic. As Clottes takes us into the painted caves, he explains how that mindset helps us understand not only what was painted and engraved, but why certain caves and walls were selected and others ignored, why the natural relief, cracks and crevices were of such importance, and the true significance of many facets which have often been seen as merely incidental. For instance, we are all familiar with hand stencils in which pigment is blown over a hand placed on the rock face, which Clottes interprets as a means to create contact with the spirit

world. But we are less familiar with the meandering finger traces and the signs of people touching the wall – practices that Clottes saw all over the world and interpreted as a way to connect with the power contained within. For him, they are as informative

“The experience of viewing cave art in situ would have been quite different to seeing glossy pictures” as spectacular images of bison and horse. Similarly, many caves have fragments of bone and animal teeth inserted into crevices and the ground, which Clottes compares not only to gestures made by recent huntergatherers to contact the spirit world but with how Orthodox Jews deposit rolled pieces of paper into gaps between the stones of the Wailing Wall in Jerusalem. Throughout the book, and no doubt his life, Clottes wrestles with the frustration of not knowing the myths that must have lain behind the paintings: how and where can one draw the limits of acceptable scientific interpretation?

He provides three examples for which it might be possible to, as he says, “detect the transposition of a myth in which the broad strokes become apparent, even if the details will forever remain beyond our grasp”. The first is a composite image of a woman and a bison, painted on a tapering hanging rock in Chauvet cave. Then there is the Lascaux painting of a spindly bird-headed man, falling backwards with an erect penis, faced with a charging bison whose guts are spilling from its wounded belly, with what appears to be a broken barbed spear and a stick on which a bird is perched. Last is a young ibex giving birth, turning its head to peer at a bird perched on its hindquarters, a theme repeated in several carvings from the French Pyrenees. For each, Clottes provides intriguing interpretations, drawing not just on the imagery but on their locations, which would have made the experience of viewing these images in situ quite different from seeing them as glossy pictures in a book – as most of us do today. He brings his fascinating book to a close by explaining how the clues within the paintings, engravings, carvings and caves point to a shamanic type of religion, one with similarities to those that he found among more recent hunter-gatherers across the world. This is an inclusive theory, one that pulls together elements of the earlier theories. It rests on almost half a century of looking and learning by Clottes and concludes with the modesty only great minds possess: “At the end of the day, if we have only very few certainties, by exercising caution and building on what is known and what is probable, I feel that we are able to approach these distant hunters of the Paleolithic with somewhat greater success.” ■

Don’t fence me in An obsessive natural history will change how you look at hedges, says Bob Holmes

FOR most people, hedges are part of the furniture of the British countryside: present but unremarkable bits of set dressing. John Wright would like to change that. In A Natural History of the Hedgerow, he brings hedges firmly into focus. Whether that’s too much of a good thing depends on how fond you are of fine detail. Wright, a naturalist who has written several books about foraging, devotes the first part of this one to a hedge-centric view of the history of rural Britain, from the Stone Age, through the rapid expansion of hedging that occurred as common fields were divided into private holdings from the 13th to 19th centuries, to the removal and neglect of hedges in the past few decades. The detail

here is fascinating or stultifying, depending on your point of view. Wright has clearly spent many, many hours measuring hedges on aerial photographs. The middle part of the book switches focus as Wright looks at the major tree species used in hedges, and some of the most prominent plants and animals that live there. Again, Wright’s eccentric, obsessive side comes through clearly, especially in his inordinate fondness for insect pests and fungal diseases. If you want to know about gall-forming insects, leaf miners and rust fungi, he’s your man. The final section considers the hedging process itself, with personal anecdotes from days spent “laying” – that is, building – hedges, and a lengthy exploration of regional styles of hedges and drystone walls. Mind you, anyone who reads this book is likely to have a harder time ignoring the next hedge they encounter, and if they pause a moment for a closer look, Wright will have accomplished his goal. ■

Corridors of power: the hedgerow was a Stone Age invention

Bob Holmes is a consultant for New Scientist

A Natural History of the Hedgerow: and ditches, dykes and dry stone walls by John Wright, Profile Books, £16.99

DAVID NOTON PHOTOGRAPHY / ALAMY STOCK PHOTO

ALBERTO PAREDES

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

Steven Mithen is professor of archaeology at the University of Reading, UK 14 May 2016 | NewScientist | 45

[email protected]

LETTERS EDITOR’S PICK

Dark dimples in baby galaxies From Ronald Diel The issues with dark matter that Stuart Clark describes got me thinking (2 April, p 30). Gravity results from the warping of space-time caused by mass. Aside from the effect of mass, however, is it possible that space-time itself did not start out smooth but instead incorporated persistent warping in the form of dimples and wrinkles? These distortions would have the effect of gravity without needing corresponding matter. They could explain the observed excess gravitation towards matter observed in galaxies and large structures without recourse to dark matter. Under this model, the early galaxies would have coalesced in the dimples, which themselves would have been aligned by the wrinkles to form large-scale structures – filaments and walls. As well as the excess of gravity, this could account for the rapid formation of galaxies and the observations of structures that are larger than expected. If, however, dark matter were the explanation, you would still have to explain how it coalesced so quickly and at such large scales. Little in nature is formed in a perfectly uniform state, so why should space-time be different? New York, US

To read more letters, visit newscientist.com/letters 52 | NewScientist | 14 May 2016

Something fishy about that fact From Chris Hughes In your interview with Timothy Leighton, he says “if you buy a farmed salmon today from North America, chances are it will have eaten a greater weight of antibiotics during its life than its own body weight” (26 March, p 32). The inherent improbability of this, given the efficacy of antibiotics and standard ratios of drug dose to organism weight, not to mention the relative costs of salmon and antibiotics, is stark. Luton, Bedfordshire, UK The editor writes: ■ Leighton based this on public statements by the UK’s Chief Medical Officer, which have been widely reproduced. We asked the Department of Health, which says: “The Chief Medical Officer’s original comment in 2014 was based on information that was supplied to her verbally, and we now understand that this information may be unreliable.”

When predicting the world fails From Jamie Carnie Anil Ananthaswamy describes the hypothesis that perception is founded on prediction (9 April, p 42). This is supported by my own experience that brain injury can cause perceptual disturbance in two ways. It can leave the processing of sensory data intact, but still disrupt the generation of predictive perceptual models. And it can disrupt the confident recall of memories needed to fluently generate these models. The result of these twin effects is a confusing state in which the processing of incoming sound and light signals functions perfectly but cognition becomes defective at precipitating out

perceptions of objects and their states. For example, I remember early in my rehabilitation having to examine domestic switches and controls for an inordinate length of time, despite their being visually fully apparent to me, to determine whether they were “on” or “off”. Bath, Avon, UK

Evolution in word selection From Andrea Stevenson Evolution is contested by those who know no better (26 March, p 5). But most of the population of the world is unlikely to grasp the basic process of evolution until science commentators regularly use language that describes its function. Currently, too many reports of evolution – more elsewhere than in New Scientist – tell of a species “choosing” to adapt or “deciding” to grow this feature or discard that. Maybe it is more cumbersome to say that a population is descended only from those whose forebears had the feature in question, or that those with this feature failed to breed. However, as long as people see the language of “choosing”, they will continue to ask: “Will the next generation have smaller fingers, ’cos, like, everybody uses mobile phones?” Benalla, Victoria, Australia

Is overeating making corals sick? From Neil Doherty Ruth Gates mentions corals expelling their microalgae colonies because of the increase in temperature from global warming (9 April, p 26). Perhaps the corals are “vomiting” because of accidental overindulgence, rather than actively ejecting the microalgae. Might the increase in food due to raised temperatures

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be the real coral killer? Barnsley, South Yorkshire, UK Ruth Gates writes: ■ The “vomiting” is not related

to an abundance of food. Under normal conditions, corals carefully regulate the number of symbionts or microalgae in their tissue. The microalgae live inside the corals’ cells, so they are ejected into the stomach, then bundled in a mucus ball, which is essentially vomited from the coral’s mouth when it contracts. This happens more rapidly when the animal suffers environmental stress.

A natural history of other morality From Donald Lang Michael Tomasello’s book A Natural History of Human Morality is definitely a must-read for all ages, but especially for educators (12 March, p 42). But it raises an obvious question: is there non-human morality? Victoria, British Columbia, Canada

The real roots of monogamy From Guy Cox David Barash is right to debunk the proposal that sexually transmitted infections explain monogamy (23 April, p 20). But he falls into another trap when he says that polygyny – men having more than one female partner – is a default human mating system. It seems to me that polygyny is the product of the development of agriculture, which enabled some men to become rich and afford more than one “wife”. Battles over land killed many young men, leaving a surplus of women who would otherwise get no partner. Hunter-gatherer societies weren’t like that. The most widespread such societies to survive into modern times are

“You will always be yourself as long as there are people to remember who you were” Claire Davies on the play Elegy, which explores the loss of the self (newscientist.com/article/2086643)

those of Indigenous Australians: in these societies, marriage was monogamous, and men couldn’t become rich because all wealth was shared. Sydney, Australia

Your android is not paranoid enough From Malcolm Drury Aviva Rutkin reports machines teaching themselves to grapple with the real world (19 March, p 20). Impressive though progress is, I don’t believe an artificially intelligent entity will be judged quasi-human until it professes to feeling very depressed, in spite of having a brain the size of a planet. Ottawa, Ontario, Canada

Wide-eyed and very far away From Tim Stevenson You report Mike Brown saying that from the distance of the Oort cloud “the sun appears so small TOM GAULD

that you could completely block it out with the head of a pin” (19 March, p 30). Since in such dim light the iris of the eye would be larger than a pinhead, a pin could not block out even a point source. Prestwood, Buckinghamshire, UK

Trust no one when it comes to free will From John Hastings Alun Anderson’s review of The Mind Club by Daniel Wegner and Kurt Gray was fascinating, almost persuading me to buy the book (23 April, p 44). Then it occurred to me that their ideas applied to themselves: their interpretation of evidence depends on the “roiling, preconscious electrical activity” of their brains. How do we know that this produced sound conclusions? In 1927, J. B. S. Haldane wrote that “If my mental processes are determined wholly by the motions of atoms in my brain, I have no reason to suppose that my beliefs are true. They may be sound chemically, but that does

not make them sound logically.” Neuroscience has progressed since Haldane’s time, but surely we cannot trust the conclusion that we have no free will when it is made by people who selfconfessedly have no free will and are therefore not free to come to any other conclusion. Whittlesey, Cambridgeshire, UK

Interstellar probes work both ways From Ian Payne Billionaire Yuri Milner and physicist Stephen Hawking suggest that sending a probe to Alpha Centauri is practical, and it will take only 20 years to get there (16 April, p 9). If true, this would mean that the likelihood of intelligent life elsewhere in the galaxy is very much diminished. It would lead me to expect our own solar system to be full of tiny alien probes sending messages back to their own systems, which we would doubtless be able to intercept. London, UK

Costs and benefits of HIV prevention From Volkart Wildermuth You compare the cost of Truvada, used as a prophylactic against HIV, with that of treating people who are HIV-positive (2 April, p 5): “it costs £380,000 to treat an HIVpositive person for life, versus £4700 to supply Truvada for a year, so you’d have to take the drug for 80 years before it became more expensive”. This is only true if everyone taking Truvada would otherwise become HIV positive. Even in high risk populations the risk of infection is not 100 per cent. Berlin, Germany The editor writes: ■ That was a first approximation. One model compares the cost of this drug with the saving made through treating fewer HIV infections. It shows an overall saving when the drug is given to men who have sex with men if 5 per cent of them get HIV a year (The Lancet, doi.org/bfn5). This is roughly similar to the proportion of new HIV cases in gay men attending STI clinics who have had condomless sex as receptive partners in the past year.

For the record ■ The US Centers for Disease Control and Prevention in fact estimates that 25.3 million adults in the US suffer from daily (chronic) pain (Letters, 23 April). ■ The person developing a device to distinguish types of infections is called Ravi Verma (30 April, p 16).

Letters should be sent to: Letters to the Editor, New Scientist, 110 High Holborn, London WC1V 6EU Email: [email protected] Include your full postal address and telephone number, and a reference (issue, page number, title) to articles. We reserve the right to edit letters. Reed Business Information reserves the right to use any submissions sent to the letters column of New Scientist magazine, in any other format.

14 May 2016 | NewScientist | 53

For more feedback, visit newscientist.com/feedback

FEEDBACK

PAUL MCDEVITT

JOHN WARD is keeping one eye on the skies after receiving an email from the travel planning site Orbitz that told him “Flights to San Diego are dropping”. “Should I dig an underground shelter?” worries John. “I know I won’t be flying into or out of San Diego airport until this situation is remedied.” However, Feedback thinks that boarding a flight that never dropped might prove tricky.

READERS of a certain age will recall the televised adventures of Dr Sam Beckett, a physicist forced to hop through time “to put right what once went wrong” in the series Quantum Leap. Fans will be thrilled to hear that US mystic Burt Goldman is offering a master class in Quantum Jumping, a similar technique that offers students “a universe of infinite possibilities”. Quantum Jumping gives you the chance to put right what once went wrong in your own life, by tapping into the accumulated wisdom of the many alternative versions of yourself living in the multiverse. Goldman says this wisdom rests in your subconscious, so there’s no need to run the risk of climbing into a malfunctioning time machine like Beckett did. Feedback can’t help but wonder if there really were infinite versions of us “wanting to connect”, it could be to ask advice instead of offer it. What if we are already living in the best of all possible worlds? Oh boy.

CHRIS SMITH finds food for thought in a block of Anchor mature cheddar. On the one hand, the packaging’s boast that it is “Slowly Matured / Since 1886” may be more than he bargained for. Yet the packet also provides a zip-seal to “lock in the freshness”. Chris wonders “what criteria are used to decide when it is mature enough for sale, but hasn’t lost its freshness?” RESIDENTS of Bristol, UK, are kicking up a stink over the city council’s decision to use vinegar to control weeds, reports John Pidgeon. The pungent herbicide was selected after environmentalists campaigned against the use of glyphosate and other such “chemical” weedkillers. But a trial run of the alternative has prompted complaints that corners of the city now smell like a fish and chip shop. The delicious smell of success?

While searching for information about sleep apnoea, Jeffrey Noel Ethridge discovered eminently qualified expert Dr Farkas in New York – first name Gaspar 56 | NewScientist | 14 May 2016

PREVIOUSLY the Helen as a unit of beauty was recalled by Andrew Harper, with the more practical subunit of the milli-Helen, defined as the amount of beauty necessary to launch a single ship (23 April). Brennan Wilson writes that the expression dates back to at least 1958. When his sister Helen was christened, his grandfather Malcolm “cracked – or repeated – the joke that a milli-Helen was all that could be wished for in any individual case.” Brennan adds that “my own sister has undoubtedly lived up to expectations, as she has competed in the Irish national dinghy sailing team, and has thus launched a number of ships or boats.”

MEANWHILE, Richard Mellish is more concerned with the correct use of the unit. “Although it is obviously not an SI unit, the same conventions should apply, so it should be helen, not Helen” he attests. This however throws up the problem of competing standards, “with H already being used for henry, the unit of inductance”. How about Hn, offers Richard, “given the precedent of a few SI units already having more than one letter?” “WITH a small sense of shame and no little cringing embarrassment,” writes Bryn Glover, “I have to confess that we schoolboys in the late 1950s did indeed use the milli-Helen as the unit of choice to rate the desirability of members of the opposite sex.” “Shame on us,” admits Glover, “but we were only spotty adolescents”.

IN FACT, the phrase appears to have provenance in our own magazine, as Stuart Butler notes, where a similar discussion occurred on the letters pages almost 60 years ago (27 November 1958, p 1400). Feedback apologises to any long-term subscribers left feeling short-changed by this recycling of content. And finally, we must credit David Morgan-Mar’s 2005 observation that while it crops up with some frequency, the milli-Helen is an irregular unit, with David arguing “you can’t mix metric prefixes with Troy units like that.” ALUN ANDERSON’S review of The Mind Club recounts the anecdote of Descartes having a mechanical copy of his deceased daughter made, only to see her thrown overboard by the crew during a sea voyage (April 23, p 44). Craig Gaston wonders if the philosopher was prompted to exclaim “She sinks, therefore she is not”.

PREVIOUSLY Feedback wondered about the capacity of a 750 ML wine bottle – that is, 750 megalitres (19 March). Having done the maths, Charles Daniels says this “turns out to be almost the size of the Empire State Building, whose shape is a bit like a wine bottle. Perhaps Godzilla could be the sommelier?”

You can send stories to Feedback by email at [email protected]. Please include your home address. This week’s and past Feedbacks can be seen on our website.

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THE LAST WORD

ago, which is when Tyrannosaurus rex and most other well-known dinosaurs lived, making their coexistence with blood-sucking insects highly likely. The conclusion that these organisms fed on other animals’ blood came from analyses of their abdominal contents. The work identified iron-containing haem – the main component of blood, which carries oxygen and gives red cells their colour. The blood meal would have contained mainly red blood cells and some white cells. In mammals, red cells lack a nucleus

provide the genetic instructions containing DNA. All other for the new organism. vertebrates have red blood What happens then? A frog is cells with a nucleus, each one an amphibian and does not make containing the whole genome. hard-shelled eggs, so would the So the DNA content would be transplanted dinosaur nucleus much higher in a blood meal develop? Who knows? from a dinosaur than in one The Jurassic Park movies may from a mammal. have brought back to life the most However, the high level of degradation meant that no whole amazing animals that ever walked blood cells were identifiable in the the Earth, but I wouldn’t recommend trying it at home. recovered fossil material. Both Alena Pance digestion of the blood and Wellcome Trust Sanger Institute fossilisation of the insect would Genome Campus almost certainly have destroyed Cambridge, UK any DNA. In addition, DNA has a half-life of approximately 500 years, and would be too broken to contain Mystery measure any information after about Why do some imperial tape measures 1.5 million years. So finding a have a mark at 16, 32 and 48 inches, complete, intact genome in a and so on? dinosaur fossil or in an insect that fed on it is highly unlikely. ■ The extra marks found at 16Let us imagine, however, inch intervals are simply the that somehow an insect was standard spacing for joists and embedded in amber just after studs in carpentry. sucking blood from a dinosaur, Joists are the horizontal beams and preserved in super-ideal that support wooden floors, and conditions. The owner of the studs are the wooden bars that extracted DNA could only be make up the frame for a hollow, pinpointed by sequencing it non-load-bearing wall that is and matching it to a reference genome. But we have no reference faced with plasterboard or other similar sheet material. Having the genome for a dinosaur, so there would be no option but to try it “Having the interval marked and see what comes out. on tape measures saves For that, we would need a the carpenter from having whole, undamaged nucleus to transplant by injecting it into, say, to learn the 16 times table” an unfertilised frog egg with its intervals marked like this saves own nucleus removed. The frog the carpenter from having to egg would provide everything know the 16 times table. necessary for development, and Prompted by this question, the transplanted nucleus would

The writers of answers that are published in the magazine will receive a cheque for £25 (or US$ equivalent). Answers should be concise. We reserve the right to edit items for clarity and style. Please include a daytime telephone number and an email address if you have one. New Scientist retains total editorial control over the published content. Reed Business Information Ltd reserves all rights to reuse all question and answer material that has been

submitted by readers in any medium or in any format and at any time in the future. Send questions and answers to The Last Word, New Scientist, 110 High Holborn, London WC1V 6EU, UK, by email to [email protected] or visit www.newscientist.com/topic/lastword (please include a postal address in order to receive payment for answers). Unanswered questions can also be found at this URL.

Dino DNA I recently watched the movie Jurassic Park and its sequels, in which DNA from the stomachs of mosquitoes stuck in amber was used to recreate the dinosaurs. Could you do this in real life?

■ Insects appeared on Earth together with plants around 480 million years ago, but the earliest record of blood-feeding insects is much more recent. A mosquito found encased in rock in Montana is reckoned to have lived 46 million years ago, and another blood-feeding bug discovered in China predates that mosquito by 30 million years. This falls within the early Cretaceous, between 142 and 64 million years

“Finding a complete, intact genome in a fossil or an insect that fed on a dinosaur is highly unlikely”

I checked the spacings of the joists in the floors of my Victorian house, and they are at about 18 inches. Perhaps the Victorians could afford thicker floorboards that needed less support. Interestingly, I have a metriconly tape measure which doesn’t have marks at 40-and-a-bit centimetres (the metric equivalent of 16 inches). David Jackson Liverpool, UK

This week’s questions MORNING COMPOST

I routinely add coffee grounds and tea bags to the compost that I put in my wormery. What effect, if any, would residual caffeine have on earthworms and other invertebrates? Olwen Williams Cambridge, UK TIDE AND TIME

We know that the moon used to be much closer to Earth. What kind of tides might there have been back then? Patrick Casement London, UK NATURAL COLOUR?

Is it possible for a light source to be anything other than white or a colour in the spectrum? For example, can one shine a brown light, or a pink one? Neil Croll Allestree, Derbyshire, UK

Question Everything The latest book of science questions: unpredictable and entertaining. Expect the unexpected Available from booksellers and at newscientist.com/questioneverything

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