New scientist 8 october 2016

WORRYING TIMES

The truth about the anxiety epidemic

LOST WORDS

The birth and death of a unique language

NUCLEAR POWER PLAY

Time to get serious about North Korea’s bomb

WEEKLY 8 October 2016

130 NOT OUT What’s the upper limit of longevity?

the reaction that will change the world Crack it and we can burn fossil fuels forever

ISSN 0 2 6 2 - 4 0 7 9 4 0 No3094 £3.95 US/CAN$5.95

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DELIGHT OF THE BUMBLEBEE Insects get emotional

Contents

Volume 232 No 3094

This issue online newscientist.com/issue/3094

Leaders

News

5

8

News

Kids walk after DNA therapy

6 UPFRONT

Key species score a conservation victory.

Rosetta’s final act. Nobel prize round-up 8 THIS WEEK Hidden ice found inside Hawaiian volcano.

Bees can be optimistic and happy. The limits of human lifespan. China wants a space plane for tourists. Men get violent if outnumbered by women. Artificial killer cells mimic simple ecosystem 14 IN BRIEF

Budgies always swerve right. Cannibal galaxy. Bendy, bouncy 3D-printed bones

zephyr/science photo library

Drug breakthrough gives hope for treating neurological diseases

The loss of a language is not always a disaster. A hard line on crime can backfire

On the cover

28

32 Worrying times The anxiety epidemic 36 Lost words Language birth and death 18 Nuclear power play Time to get serious about North Korea’s bomb 10 130 not out The limits of longevity 9 Delight of the bumblebee Insects get emotional

The reaction that will change the world Crack it and we can burn fossil fuels forever

Cover image John Randall

Analysis 18 North Korea’s nukes Is it time to start worrying about Kim Jong-un’s nuclear plans?

20 comment

For an optimum Brexit deal, take your time.

What should we do if insects have feelings?

21 insight Elon Musk’s vision alone won’t get us to Mars

Technology 22 Artificial intelligence gets common sense.

3D printing on the move. Material morphs to its own molecular clock

Aperture

Features

32

26 The crimson beauty of industrial waste

Worrying times

28 The reaction that will change the world (see above left) 32 Worrying times (see left) 36 Lost words The birth and death of a unique language 40 PEOPLE The Comte de Buffon’s cold Earth model

Russell Johnson/EyeEm/Getty

The truth about the anxiety epidemic

Features

Culture

Coming next week…

Running on empty

Why do we feel tired all the time?

Predicting history

The computer that holds the secrets of the past

42 E-paradise lost Rethinking the internet 43 Missing picture We can’t talk about gene editing without calling for tough regulations 44 Furry friends, not What cats are really like

Regulars 52 letters More perverse biofuel incentives 56 Feedback Using trickery to do good 57 The Last Word Seal meal

8 October 2016 | NewScientist | 3

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by Williams Gibbons (Wolverhampton)

Unspoken assumptions The loss of a language is not always an unmitigated disaster DOES it matter if a language dies out? The orthodox answer is that it does, because every language is a repository of ideas and culture and embodies a unique way of looking at the world. The planet only has about 7000 languages; the extinction of even one diminishes the sum total of human knowledge.

But in some cases, extinction can be seen in a more positive light. Take Al-Sayyid Bedouin Sign Language (ABSL), restricted to about 1000 users in a small Israeli village with a high level of congenital deafness. The language seems doomed by the spread of Israeli sign language (see page 36).

The instinctive reaction is regret, and from a linguistic

perspective the loss of ABSL is a genuine shame. It is a fascinating language that has kept linguists busy since it came to their attention around 15 years ago.

But for the deaf villagers, Israeli sign language is an upgrade: it allows them to speak to tens of thousands of people rather than a few hundred, and enables them to work and marry outside the village. It is hard to see that as anything other than progress.

The same is sometimes true for other endangered languages: they die out because people abandon them in favour of ones that serve their needs better.

Technology also softens the blow, as endangered languages can now be captured in detail –

Tough on the causes...

ONE of the worst spectacles of the US presidential election has been the resurgence of racially charged politics. Donald Trump is stoking fears of an explosion of violent crime in inner cities – a tactic widely seen as a racist dog whistle.

Unlike lots of Trump’s “facts”, there is a grain of truth in this one.

There has been a recent rise in violent crime in some major cities. Solving this, and dispelling

racial tensions, should be high on the political agenda.

Conservatives and liberals will disagree on the causes, but now researchers have uncovered a counter-intuitive factor: areas with more women than men have higher levels of violent and sexual crime (see page 12).

In the US, skewed sex ratios are common in African-American communities, where high levels of

which also means they could eventually be brought back from the dead, much as the language of the Israelites was in the 19th century. Hebrew is now the first language of 9 million people.

Linguists instinctively decry the loss of language much as conservationist biologists once mourned the loss of every single species. But conservation is in the midst of a paradigm shift, moving towards acceptance that not all species can be saved, that invasive species are not always bad and that human-engineered ecosystems are not necessarily inferior to natural ones. Perhaps our attitudes to language extinction are due for a similar heretical change. n

male mortality and incarceration mean there are nine or fewer adult males for every 10 women.

Census data reveals the depth of the problem. The vast majority of white and Hispanic people live in communities with roughly equal sex ratios. More than 90 per cent of black people do not.

Sex ratios are clearly not the only factor in play. But those who advocate tough-on-crime policies with high levels of incarceration may be unwittingly fuelling the fire they are trying to put out. n 8 October 2016 | NewScientist | 5

ESA/ROSETTA/MPS FOR OSIRIS TEAM MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

UPFRONT

Rosetta’s final bow GOODBYE, Rosetta. On 30 September,

Rosetta launched in 2004 and

the European Space Agency probe landed on comet 67P/ChuryumovGerasimenko, in a spectacular finish to its two years spent in orbit around the space rock.

Rosetta, never designed to land, was probably badly damaged on impact, despite coming in at a speed of just 1 metre per second. Its last signal, transmitted at the moment of landing, reached Earth at 12:19 BST. We will never hear from it again.

The mission team hugged, clapped

spent 10 years catching up with 67P. It reached the comet in August 2014 and beamed back images of an alien landscape waiting to be explored.

In November that year, Rosetta’s companion lander, Philae, made a bumpy touchdown and survived for a few days on the comet before being lost – though Rosetta did eventually find it again.

As comet 67P moved away from the sun, Rosetta’s solar panels delivered less and less power,

and cried as Rosetta’s final moments were confirmed. “I can announce full success of this historic descent towards 67P,” said Rosetta mission manager Patrick Martin. “Farewell Rosetta, you’ve done the job. That was space science at its best.”

meaning the mission would always have to end now.

“Everybody is very sad. On the other hand, the mission end had to come, and this is a spectacular way to do it,” said Paolo Ferri, head of ESA mission operations.

Wildlife wins

African grey parrots, all species of pangolins, and Barbary macaques.

“Most of the decisions favour protection of animals for the long term, so overall it’s been a very strong pro-conservation agenda,” says Kelvin Alie from the International Fund for Animal Welfare.

Several species of sharks and rays were also newly listed under the convention, and countries voted to defeat a controversial proposal by Swaziland to permit sales of white rhino horn. But a motion to expand protection to all African elephants failed.

–One of Rosetta’s final shots–

Nobels unveiled

Haldane said he “was very surprised and very gratified” to receive the award.

Many had expected the discovery of gravitational waves to win, but the LIGO team’s announcement just missed the Nobel cut-off date of 31 January.

The prize in physiology or medicine went to Yoshinori Ohsumi at the Tokyo Institute of Technology for his work on autophagy, the process by which cells recycle and repair themselves. His discoveries are vital for understanding how cells respond to stress and infection.

PRETZELS and recycling featured in this year’s Nobels as New Scientist went to press.

The physics prize went to three British scientists, David Thouless at the University of Washington,

Duncan Haldane at Princeton University and Michael Kosterlitz at Brown University. They looked at superconductors and other unusual states of matter using topology, the mathematical description of shapes.

Topologically, a bagel is different from a pretzel because one has one hole while the other has two.

Thouless and Kosterlitz used topology to show how superconductivity can appear in extremely thin materials.

Haldane used the same ideas to explain the magnetic properties of some materials.

The work could lead to breakthroughs in electronics.

6 | NewScientist | 8 October 2016

CYRIL MLINAR

“ Topology helped to show how superconductivity can appear in extremely thin materials”

IT HAS been a red-letter week for many of the world’s most iconic and threatened species. The only tinge of disappointment was a failure to win complete protection for elephants and lions.

Overall, the meeting of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, in Johannesburg, South Africa, voted en masse to back outright bans on the wildlife trade. These cover the parts and tissues of a whole host of threatened species, including

Baby dragons IT WAS touch and go for a while.

But the elusive pink aquatic salamanders that hatched inside Slovenia’s Postojna Cave about four months ago have survived the most difficult stage of their lives, reaching adolescence.

“These are the only baby dragons in the world known to humanity,” says Sašo Weldt, a member of the conservation team taking care of the creatures, –Pretty in pink– called olms.

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

Frog beats fungus

They were once only known from specimens washed out of caves by flooding and legend had it they were baby dragons – a nickname that stuck. They can live to be 100 years old and only lay eggs once or twice a decade.

So it was remarkable to see 64 eggs laid by a single individual earlier this year. They were placed in an aquarium within the cave. In total, 22 eggs hatched, and all are still alive and developing better than expected, says Weldt. Small populations and water pollution in its habitat in the Dinaric Alps in the Western Balkans means the species is classed as vulnerable.

FOR decades a deadly fungus has been killing amphibians around the world, driving many to the brink of extinction, or worse.

But now one frog’s recovery shows that, with a little luck and habitat preservation, some may evolve resistance after all.

The Sierra Nevada yellowlegged frog from the mountains of California has been declining for more than 100 years, due to non-native predatory trout and the deadly chytrid fungus.

“By the early 2000s, it had disappeared from 93 per cent of

60 Seconds

its historical localities,” says Roland Knapp at the University of California’s Sierra Nevada Aquatic Research Laboratory.

But its numbers are recovering by an average of 11 per cent per year, according to Knapp’s team, who analysed 7000 population surveys from the past 20 years in Yosemite National Park (PNAS, doi. org/brch).

There are fewer non-native fish.

And, the frogs have developed some resistance to the fungus.

“This shows there is hope that at least some species can recover, given the time and the habitat in which to do it,” Knapp says.

Hurricane Matthew batters Haiti

Rocket escape drill

NOAA

SPACE flight firm Blue Origin HAITI has been pummelled by hurricane Matthew, which brought was preparing for its most flooding and violent winds when it dramatic trial yet as New Scientist hit on Tuesday. One person had been went to press: a test of an in-flight killed as New Scientist went to press. escape system, designed to carry One of the strongest Atlantic future space tourists to safety in storms for nearly a decade, the an emergency. hurricane could dump up to a metre The company has already of rain and generate winds of 230 flown its reusable New Shepard kilometres an hour, raising fears rocket four times, launching about flash floods and mudslides in its uncrewed capsule into space the western hemisphere’s poorest and then returning the rocket country. safely to the West Texas desert.

Thousands have been evacuated The escape system is designed from parts of neighbouring to separate the capsule from Dominican Republic, and heavy the rocket. For the test flight, rain and wind has hit Jamaica, it will jettison the capsule 45 with flooding blocking roads in the seconds after launch, when capital, Kingston. the rocket has climbed nearly Rural areas in south-west Haiti are 5000 metres.

The capsule, with room for six, will blast its motor for less than 2 seconds, enough to carry it away to safety. But in doing so, the motor will knock the rocket back with a force of more than 300,000 newtons, likely inflicting severe damage on it.

As the capsule parachutes back to Earth, the rocket will most probably plummet to the ground.

Still filled with unused fuel, its landing will be decidedly explosive rather than soft.

If New Shepard somehow manages to survive, the company –Not just another storm– says it will put it in a museum.

forecast to see the heaviest rain and most punishing winds.

“Wherever that centre passes close to would see the worst winds and that’s what’s projected to happen for the western tip of Haiti,” says John Cangialosi at NOAA’S National Hurricane Center in Miami, Florida.

Rain is also a major concern, he adds.

The Category 4 hurricane is forecast to move north over eastern Cuba and then the Bahamas, before striking the US east coast later this week. Florida and parts of North Carolina have already declared states of emergency.

Matthew briefly reached the top classification, Category 5, becoming the strongest hurricane in the region since Felix in 2007.

SpaceX investigation SpaceX has launched an inquiry into how its Falcon 9 rocket blew up during a routine test a month ago.

According to the Washington Post, this means SpaceX has not ruled out the possibility of sabotage, although that remains unlikely. Congressman Mike Coffman has urged government agencies to take over the case, to protect future NASA crews slated to fly with SpaceX to the ISS.

The ugly truth Unattractive friends may make you look more fanciable, tests with volunteers suggest. They had to rate pictures of different faces for attractiveness, viewing them singly at first, then again with images of less attractive people alongside. The original faces scored more highly the second time around (Psychological Science, doi.org/brbn).

Bees on their knees Bees have appeared on the US endangered-species list for the first time. All native to Hawaii, the seven species of yellow-faced bees are threatened by non-native animals and by development. The bees pollinate some of Hawaii’s indigenous plant species, many of which are themselves threatened.

Poles’ pro-choice strike Thousands of women in Poland went on strike on Monday to protest a plan to ban abortions. The proposal, from an anti-abortion grassroots campaign, is being examined by a parliamentary commission and would make all abortions illegal, even in cases of rape or when the woman’s life is at risk.

A titan’s footprints One of the largest ever dinosaur footprints has been unearthed in the Gobi desert. The well-preserved fossil is 106 centimetres long and 77 centimetres wide, and is thought to have been made by a titanosaur – a long-necked herbivore that may have been 20 metres tall.

8 October 2016 | NewScientist | 7

This week

Children walk after drug breakthrough it doesn’t last long, let alone get into cells. So biologists have spent decades trying to create synthetic forms that can survive in the body. They have strengthened the DNA backbone, for example, to help it bind more strongly to RNA. They have also made tweaks that help it enter nerve cells.

Nusinersen is one such modified antisense drug. Reports of its success have created great excitement among parents of children with spinal muscular atrophy, but we need to be cautious about individual reports, says neuroscientist James Sleigh at the University of Oxford.

Even if the final results show nusinersen doesn’t work as well as hoped, there is still cause for optimism. Animal studies, and postmortems of children who died despite being given

“TO SEE children who would have been dead sitting and standing is something I never thought I would see.”

Francesco Muntoni, at University College London, is talking about videos of children given an experimental drug for treating spinal muscular atrophy.

This genetic disorder involves the deterioration of nerves connecting the brain and spinal cord to the body’s muscles.

Children with the severest form can’t sit upright and seldom survive past the age of 2. Yet a few parents have posted videos online showing children given the drug, called nusinersen, who appear to be sitting and even walking with assistance.

The trial of nusinersen was stopped in August when it became clear it was effective, making it unethical not to give the real drug to those on the placebo.

The full results haven’t yet been published, but what has been revealed so far of this “antisense” therapy suggests we have overcome the biggest obstacle – how to deliver such therapies – at least in disorders that affect the nervous system. The breakthrough could open the floodgates for similar treatments for neurological conditions such as Huntington’s, motor neurone disease and possibly even Alzheimer’s.

Antisense drugs are essentially pieces of DNA that bind to specific RNAs – the recipe that cells use to make proteins. By binding to RNAs, they can block the production of proteins, or alter their form.

These drugs have the potential to prevent or cure many diseases.

But there’s been a huge snag: if naked DNA is injected into people, 8 | NewScientist | 8 October 2016

Zephyr/SPL

Michael Le Page

nusinersen, show widespread distribution of the antisense molecule in the brain and spinal cord, says Muntoni, who has helped develop and test therapies such as nusinersen.

These findings, and others, show it is possible to get antisense molecules into nerve cells, meaning improved versions should soon become available.

“I think it will happen surprisingly quickly,” says Edward Wild at the National Hospital for Neurology and Neurosurgery in

Wild’s team is trialling has passed initial safety tests with flying colours.

Such therapies could be used to treat a range of disorders, possibly including Alzheimer’s. There is no single mutation that causes Alzheimer’s, says Wild, but we know of several gene variations that increase the risk of the disease. In theory, blocking the production of proteins encoded by these genes could delay or prevent people becoming ill.

The downside of antisense treatments is that repeat doses “ It became clear that are required at least every few the drug was effective, months, and often for life. The meaning it was unethical drugs have to be injected directly to keep giving the placebo” into the cerebrospinal fluid, which flows around the brain and London, who is part of a team spine. This procedure, called a testing an antisense drug for lumbar puncture, can cause side Huntington’s disease. effects including headaches and This inherited condition back pain. remains untreatable despite But Muntoni and colleagues decades of attempts to develop may have found a way to modify therapies. With the delivery the antisense molecules so they problem seemingly cracked, Wild can cross the blood-brain barrier, thinks that will soon change. The meaning they can be injected into Huntington’s antisense drug that the bloodstream. Animal studies published last month suggest this approach works well, Sleigh says, but it has not yet been tested in people.

The advent of therapies for genetic conditions considered untreatable could change the way we approach them. If treatments become available for childhood disorders such as spinal muscular atrophy, it will mean children should be tested for the condition at birth so they can begin therapy as soon as possible.

It could also change the way adults approach genetic sequencing of their own genes.

At present, most people who have their genome sequenced opt not to find out if they have inherited diseases such as Huntington’s, preferring not to know their fate.

But if it becomes treatable and perhaps even preventable, they may wish to start therapies early.

“As soon as we have something that works, people will want to get –Next on the list: Huntington’s– tested,” says Wild. n

In this section n The limits of human lifespan, page 10 n Is it time to worry about North Korea’s nuclear plans?, page 18 n Artificial intelligence gets common sense, page 22

FIELD NOTES Mauna Kea, Hawaii

ice patch still exists.

Schörghofer buried some temperature sensors here in 2013, and when we get to the third of these, a metre deep in the centre of Woodcock’s old surveying area, he lets out a whoop of excitement.

The temperature here is freezing.

To investigate further, Leopold spaces out 20 steel electrodes, each the size of a tent peg, across the survey area. These generate an electric field that can find frozen ground up to 50 metres deep by measuring resistivity. Unlike drilling, it preserves the landscape that local people hold sacred.

The readings show that the ice is still there, but its horizontal

THEY are both breathtaking, in quite different ways: the thin air 4200 metres up, and the majestically rugged, alien landscape at my feet.

I am on the summit of Mauna Kea, the highest point in Hawaii.

The red-brown basalt and barren surface of the dormant volcano conjure up images of Mars.

It was in the Pu’u Wekiu crater, in 1969, that the geophysicist Alfred Woodcock dug beneath the rocky exterior and discovered a hidden ice world. But when Norbert Schörghofer, an astronomer at the University of Hawaii at Manoa, stumbled across Woodcock’s papers decades later, “ Sadly, time is running out for a precious window on he was baffled. How could ice how and why buried ice persist in an area where the forms on the Red Planet” average temperature is 4 °C? To try to solve this puzzle, Schörghofer has enlisted the help extent has shrunk from 600 to of geophysicist and permafrost 200 square metres, and its depth expert Matthias Leopold at the halved to just 5 metres. Global University of Western Australia in warming may have played a part Perth. The goal of the expedition in this, but it’s hard to tell without I have come on is to find out long-term data. whether the subterranean The team will now combine

Bees seem to have an upbeat outlook on life DON’T worry, bee happy. Bumblebees may experience something like happiness after getting a treat, making them take a more positive view of things.

Clint Perry at Queen Mary University of London and his team trained 24 bumblebees to associate two locations in the lab, each of a particular colour, with sugar water or

plain water. They then measured the time it took them to explore a new site located midway between the two, and with an intermediate colour chosen to make the bees unsure whether it contained a sweet reward or not.

Half of the bumblebees received a sugar treat before the test, and these entered the ambiguous middle station more quickly than those that didn’t. It wasn’t simply that these were more active because of the energy boost: the effects seem to be down to the neurochemical dopamine, which plays a role in the reward system in humans.

When the bees’ dopamine receptors

–Alien terrain, but not off-world–

buried ice towards the equator.

Just like with Pu’u Wekiu, these spots lie in shadow inside the steep craters that punctuate the planet’s surface.

Not much is known about ice away from Mars’s poles, so Mauna Kea’s ice is a precious window on how and why it forms. But sadly, its time is running out. With climate change, Schörghofer believes the Mauna Kea ice will disappear over the next 50 years.

As we drive back down, the only visible hint of where we have been is the volcanic ash on our faces.

But hopefully, this won't be my last trip to Mars. n

geological and meteorological data to come up with a theory of why the buried ice persists. The most plausible explanation is that it forms at night, when temperatures drop below zero and icy air can swirl down the steep crater and seep into the porous, rocky ground. Any ice formed would normally melt in the daytime heat, but this patch sits in a dark crater.

Mauna Kea is one of the best models on Earth for studying ice within the tropics of Mars, says Schörghofer. Most of the Red Planet’s ice is at the poles, but photos have identified signs of Education Images/UIG/Getty

Alice Klein

Grant Kaye/Getty

The volcano that hides ice like Mars

were blocked, the effect was gone.

The treat also helped bees return to feeding more quickly after a simulated

predator attack (Science, doi.org/ brbc). This suggests that bumblebees carry out behaviours that go along with feelings, says Perry.

It’s exciting to see a clear demonstration of something like emotions in bumblebees, says Eirik Søvik at Volda University College in Norway – although he isn’t surprised.

“They have brains that function in pretty much the same ways as ours,” he says. “The hard part is –Sunny disposition– demonstrating it.” Emily Benson n 8 October 2016 | NewScientist | 9

Monashee Frantz/plainpicture

This week

Is our maximum lifespan 115?

Clare Wilson

OUR life expectancy has been climbing for decades – but how much further can we push it?

The maximum lifespan for most people may be around 115, because of the innate limits of the human body, according to new research. The few who have gone beyond this age are rare outliers, says Jan Vijg of the Albert Einstein College of Medicine in New York.

By analysing demographic records, Vijg’s team has found

China’s giant spaceplane fits in 20 tourists EVEN China can’t resist the lure of space tourism. A state-backed firm is developing a gigantic craft that may one day fly 20 passengers to the edge of space.

The China Academy of Launch Vehicle Technology in Beijing has designed a spaceplane that can be scaled up to carry a large number of people, academy rocket scientist Lui Haiquang told the International Astronautical Congress in Guadalajara, Mexico, last week.

10 | NewScientist | 8 October 2016

that maximum lifespan has not been rising in step with the average lifespan. The record for the oldest living person climbed to around 115 in the 1990s, after which it has broadly plateaued.

Although Jeanne Calment, a French supercentenarian who has the longest confirmed human lifespan on record, reached 122 before she died in 1997, her record has gone unbroken for nearly two decades. It shows we are not seeing increasing numbers breaking the 115 barrier, says Vijg.

There is stiff competition. Big names include Virgin Galactic, whose SpaceShipTwo spaceplane will offer six passengers trips to near-space, and XCOR, whose proposed Lynx vehicle will fly a single passenger next to a pilot. But academy team leader Han Pengxin and his colleagues believe there will be enough consumer demand to build a higher capacity spacecraft.

Han’s team has designed two versions of a spaceplane that takes off vertically under its own rocket power.

The first has a mass of 10 tonnes and a wingspan of 6 metres. This one, he says, should be able to fly five people to an altitude of 100 kilometres – where space officially begins – at

been repeatedly broken. “It is disheartening how many times the same mistake can be made,” he says.

At the start of the 20th century, average lifespan in the West was in the mid-40s, and has risen to about 80 today. Much of the initial rise came from fewer child deaths. Around the 1970s onward, further increases in life expectancy have been driven by older people dying later.

This is mainly thanks to better –Spring chickens– healthcare, such as widespread use of medicines to lower blood “115 is like a borderline – you can’t pressure and cholesterol levels. cross that unless you’re an Tom Kirkwood of Newcastle exceptional individual.”

University, UK, disagrees with the The team analysed more than idea of a limit to human lifespan: a century’s worth of records from “The idea does not really fit what the four countries with the largest we already know about the documented number of people biology of the ageing process. aged 110 or over – the UK, US, There is no set programme for France and Japan. ageing – the process is driven by They found that the rise in the build-up of faults and damage average lifespan is mostly caused in the cells and organs of the body, by people dying later at ages which is malleable.” below about 110. For people older Richard Faragher of the than that, improvements in University of Brighton, UK, thinks survival fall off sharply (Nature, innate limits on lifespan are DOI: 10.1038/nature19793). “plausible” – yet the findings don’t But James Vaupel of the Max necessarily mean we can’t extend Planck Institute for Demographic our lifespan further in future.

Research in Rostock, Germany, “I am positive that the human says many predictions about maximum lifespan could be raised limits to lifespan have been beyond 122 using technologies proven wrong, as records have that exist now,” he says. n

speeds up to Mach 6, giving 2 minutes

from a commercial spaceport, with

of weightlessness.

But a scaled-up, 100-tonne version, with a 12-metre wingspan, could fly 20 people to 130 kilometres at Mach 8, with 4 minutes of weightlessness.

The larger spacecraft is fast enough to help deliver small satellites into orbit, with the help of a small rocket stage add-on that would sit on top of the vehicle. They also intend to make it reusable, so each plane should be good for up to 50 flights.

He imagines flights will take off

payload launches in 2020. The plane will carry people when it is considered safe enough. Han predicts that a ride will cost between $200,000 and $250,000.

Some remain sceptical, however.

“The fact that they think they can test fly in the next 2 years is remarkable,” says Roger Launius at the Smithsonian Institution’s National Air and Space Museum in Washington DC, who was concerned by the lack of technical details. So the onus is on the academy to prove this is more than a paper spaceplane, he says. “It is always easier to draw illustrations and talk possibilities than to build and fly spacecraft.” Paul Marks n

“ A 100-tonne version, with a 12-metre wingspan, could fly 20 people to 130 kilometres at Mach 8”

This week

Men get violent if women are aplenty

Artificial cells mimic life and obliterate prey CELL-LIKE structures have been designed to kill another population of artificial protocells, mimicking a crucial step in the evolution of life: creatures eating one another.

The hope is that they could one day be custom made to deliver drugs. And they might just help us understand how complex cellular communities first evolved.

We think protocells were the microscopic precursors to living cells.

Building artificial protocells from substances such as fatty acids and proteins allows us to study how life might have originated. Stephen Mann 12 | NewScientist | 8 October 2016

men in a county correlated with fewer crimes – even when accounting for other potential contributing factors such as poverty. The results suggest that current policies aimed at defusing

Andrew Testa/Panos

MORE men inevitably means more testosterone-fuelled violence, right? Wrong, according to an analysis exploring how ratios of men to women affect crime rates across the US. In areas where men outnumber women, there were lower rates of murders and assaults as well as fewer sex-related crimes, including rapes, sex offences and prostitution. Conversely, higher rates of these crimes occurred in areas where there were more women than men.

Ryan Schacht at the University of Utah in Salt Lake City and his colleagues analysed sex-ratio data from 3082 US counties, provided by the US Census Bureau in 2010.

They compared this with crime data for the same year, issued by the US Federal Bureau of Investigation. They only included information about women and men of reproductive age.

For all five types of offence analysed, rising proportions of

violence and crime by reducing the amount of men in maledominated areas may backfire (Human Nature, doi.org/brbb).

When women are in short supply, men perceive them as being a more valuable resource, says Schacht. Consequently, men must be more dutiful to win and retain a female partner. In an abundance of women, men are spoilt for choice and adopt promiscuous behaviour that

brings them into conflict with other men, and makes them more likely to commit sex-related offences.

“Work in animals also shows quite similar findings to ours, that when females are abundant and males rare, males are more violently competitive, more promiscuous and less likely to invest in offspring,” says Schacht.

“Schacht’s findings are in line with ‘mating-market theory’,” says David Buss of the University of Texas at Austin. The results tally with his own work, which shows that when women outnumber men, there are more short-term relationships, divorce rates increase and men become more reluctant to commit to one partner.

The upshot, says Schacht, is that men alter their behaviour to suit conditions of supply and demand. “In some situations they will be much better behaved, and in others they will be much more prone to nasty behaviour,” he says.

The work also has implications for crime prevention, he says: “We are overly focused on male excess when we should reorient to places with more women.”

–More women, more fights– Andy Coghlan n

at the University of Bristol, UK, and his team made a community of these cells to find out if they would display the classic ecological setup of predatory

another, that you might expect to see from living, interacting beings. But because they aren’t actually alive – they can’t replicate on their own and

of artificial cells, all interacting and exchanging information. This could be used in medicine and materials science, Mann says. “Ultimately,

behaviour.

They designed a death match between two protocell populations.

The predator cells were positively charged droplets containing a protein-degrading enzyme. Their prey were negatively charged capsules of protein encircling a bit of DNA. The cells were attracted by their opposing charges, and the enzyme from the predator cells “drilled” through the protein membrane of their victims, obliterating them in under an hour and sucking up DNA in the process (Nature Chemistry, DOI: 10.1038/nchem.2617).

These protocells display habits,

they don’t evolve – their behaviour highlights how easily we might be deceived in our search for extraterrestrial life, says Steven Benner at the Foundation for Applied Molecular Evolution in Alachua, Florida. “If you were to see that in a

our vision is to think about protocell ecosystems,” he says.

Although the protocells aren’t alive, their predatory interactions suggest that competition is possible between non-living things, says Neal Devaraj at the University of California, San Diego.

That brings the field one step closer to perhaps someday demonstrating protocell evolution and even artificial life, he says.

In the meantime, Devaraj says it would be interesting to see if the predator protocells could recognise a biological signature. Such killer protocells could then be used to battle particular disease-causing bacteria.

Emily Benson n

such as moving and eating one

“ If you were to see this type of behaviour in a sample from Mars, people would mistake it for a life form” sample from Mars, people would be writing PhD dissertations about this being a life form,” he says.

Eventually, Mann’s team hopes to build a community of even more types

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IN BRIEF Stars’ spin turns weather weird

Boobs devour themselves when breastfeeding is over WHEN a woman stops breastfeeding, her breasts go from milk-producing factories to regular appendages. Now a

doesn’t typically happen when breastfeeding ceases.

Instead, it seems that epithelial cells eat their dead neighbours. Nasreen Akhtar at the University of Sheffield, UK, wondered if a protein called Rac1 is involved. She found that mice lacking the gene for Rac1 weren’t able to feed pups beyond their first litter. Without Rac1, dead

switch has been found that controls this transformation, and it could have implications for treating breast cancer.

During pregnancy, epithelial cells in the breasts proliferate and form structures that make milk. Once breastfeeding stops, these structures self-destruct. But how does the body remove all that debris? Usually, immune cells would do that job, gobbling up the dead

cells and milk flooded the breast when lactation had finished, triggering inflammation and impairing tissue regeneration (Developmental Cell, doi.org/bq8q).

Although prolonged breastfeeding reduces overall cancer risk, women have an increased risk of developing breast cancer for 5 to 10 years following pregnancy. One theory is that inflammation after breastfeeding may fuel

cells. Yet with that amount of material, you’d expect significant pain and inflammation – something that

cancer growth. Given Rac1 suppresses this inflammation, it may be a new target for cancer therapies.

Giant lurkers may explain lonely planets LONELY planets can blame big bullies. Giant planets may evict most of their smaller brethren from orbits, partly explaining why the Kepler space telescope saw so many single-planet systems.

Up to 80 per cent of the planetary systems Kepler has discovered appear as single planets passing in front of their stars. The rest feature as many as seven planets – a distinction 14 | NewScientist | 8 October 2016

dubbed the Kepler dichotomy.

What’s more, multi-planet systems tend to have circular orbits all in the same plane, and singletons’ orbits tend to be elliptical and tilted.

Now, a pair of computer simulations suggest that hidden giants may lurk in these single systems. They show that gravitational interactions involving giants in outer orbits

can eject smaller planets from the system, nudge them into their stars, or send them crashing into each other. The giants pull the few remaining inner planets into more elliptical and inclined orbits – the same kind seen in many of the single systems Kepler has spotted (arxiv.org/abs/1609.08110).

But bullying giants can only account for about 18 per cent of Kepler’s singles (arxiv.org/ abs/1609.08058), so something else must be at work as well.

LIKE a movie on fast-forward, planets orbiting rapidly spinning stars might whip through their seasons in double time.

Earth’s tilt gives our planet its seasons. But hot, massive “earlytype” stars can spin almost 100 times faster than the sun, creating a midriff bulge. The gas around the star’s equator is then further from its centre, so it cools more than other parts of the star’s surface, while the poles remain hot and dense.

John Ahlers at the University of Idaho in Moscow wondered how this might change the seasons on an orbiting planet. If its orbit is angled, it would be directly over the star’s chilled equator twice in each orbit, and would have two summers and two winters a year.

Ahlers found that difference could mean the planet’s surface would oscillate rapidly between a boiling hellscape and a frozen tundra (arxiv.org/abs/1609.07106).

Bee fossil reveals early human abode A FOSSILISED bees’ nest might tell us a lot about a key early human. The skull of an apelike Australopithecus discovered in South Africa in 1924 – known as the Taung Child – overturned our view of human origins. It suggested humans evolved in Africa, not Eurasia.

Now Philip Hopley at Birkbeck, University of London and his colleagues are studying a bees’ nest found at the same site. The bees would have nested on open ground, so the rocks around were probably formed in an arid habitat full of flowering plants – and aren’t cave rocks as previously thought. This means there may be more fossils beyond the small site previously believed to have been a cave (PLoS One, doi.org/bq8j).

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

A BOUNCY, bendy, 3D-printed bone could revolutionise implants for facial deformities and reconstruction.

Current implants are often brittle and so break easily and can’t be remodelled during surgery. Now, an ink has been developed that can be used to 3D print bone implants in any size, shape and form – from leg bones to entire skulls. And because the implants are flexible, they can be cut into the perfect shape in the operating theatre.

The ink is made from hydroxyapatite, a mineral found naturally in bone, and PLGA, a polymer that binds the mineral particles together and gives the implants their elasticity.

“We were very surprised to find when we squeezed an implant, it bounced back to its original shape,” says Ramille Shah at Northwestern University in Chicago.

Once in place, the implants are rapidly infiltrated by blood vessels and gradually turn into natural bone (Science Translational Medicine,

JAKUS ET AL

doi.org/bq8r). This offers a cheap and versatile way to repair an injury.

Shah’s team calls the implant material “hyperelastic bone” and says it could be used for many treatments, from dealing with fractures and spine repairs to implants to rebuild faces after injury or chemotherapy.

Milky Way’s baby brother copies its star-shredding habit THE Milky Way’s brightest satellite galaxy stands accused of the same crime as itself: tearing apart a celestial object that wandered too close.

The Large Magellanic Cloud is the brightest of more than 50 galaxies that orbit our own.

Big spiral galaxies like the Milky Way are known to tear up and devour their neighbours, including some of the Large Magellanic Cloud’s brethren.

But the satellite galaxies themselves have never been observed doing the same.

Now Nicolas Martin of the University of Strasbourg in France and his colleagues have spotted what looks like a globular cluster – a tightly packed group of stars – in distress. The cluster is on the outskirts of the Large Magellanic Cloud, about 42,000 light years from its centre.

The team found the star cluster in March as part of a search called the Survey of the Magellanic Stellar History (SMASH), so they named the cluster SMASH 1. And it does indeed seem headed for a smash-up. It is elongated, and its

long axis points right at the Large Magellanic Cloud, suggesting that the galaxy’s gravity is yanking it apart.

Still, if the star cluster has been orbiting the galaxy for a long time, it is strange that the destruction is occurring only now.

The cluster may have originally circled the nearby Small Magellanic Cloud, whose weaker gravity didn’t have the same effect. Only recently did the Large Magellanic Cloud snatch the cluster and begin shredding it (arxiv.org/abs/1609.05918).

ROLAND SEITRE/MINDEN PICTURES

3D-printed bone offers flexible fix

Sound blasting to scare off whales WARNING signals to deter minke whales from wind farm construction sites are being tested in Iceland. The deterrents involve a series of amplified electronic pulses projected into the water, and were originally developed to stop seals from stealing farmed fish.

A 40-day trial run by the Carbon Trust is looking at whether they might also help ward off whales during noisy pile-driving activity in the North Sea. The deterrent pulses, while annoying to whales, aren’t harmful.

“Noise pollution threatens whales because it interrupts their normal behaviour and can drive them away from important breeding and feeding areas,” says Danny Groves from the charity Whale and Dolphin Conservation.

“Excessive noise levels underwater can also cause injury and, in some cases, death.”

Minkes are thought to be abundant in many of the areas earmarked for wind farm development, which can be noisy for days on end.

The hope is that the pulses could make whales avoid the area during construction. The results are expected early next year.

Here’s how budgies avoid collisions HOW do birds avoid crashing into each other when approaching head-on? They have an inbuilt preference for veering right.

the rare occasions that one swerved left (PLoS One, doi.org/bq8h).

Group hierarchy may dictate which bird opts to fly above the other.

Mandyam Srinivasan at the University of Queensland, Australia, and his colleagues uncovered the simple trick when filming pairs of budgerigars flying towards each other in a narrow tunnel.

During more than 100 tests, the birds moved to each other’s left side in 84 per cent of cases, and never crashed. They also tended to fly past each other at different heights, which prevented mid-air collisions on

“It looks like the dominant birds prefer to go lower,” Srinivasan says.

“Maybe it’s more energy efficient and easier to go lower than higher, so the non-dominant bird is forced to gain altitude.”

These crash-avoidance strategies have evolved over 150 million years in birds and may inspire anti-collision systems in drones, “especially now that drones are being built in large numbers”, says Srinivasan.

8 October 2016 | NewScientist | 15

The secret science in your home

Fabric care: the secret revolution Fabric care used to be just about stain removal. Now clever chemistry can also keep clothes looking newer for longer YOU’RE probably familiar with the life cycle of a T-shirt. At first, you wear it with pride, perhaps washing it reluctantly to preserve its newness.

But as the lustre fades, you demote it to house wear before eventually consigning its faded glory to the back of the wardrobe.

Washing plays a key role in this life cycle.

Improper washing may cause colours to fade, fabrics to stretch and seams to break. It’s easy to feel that your cherished outfits deserve better. Why should washing new clothes provoke such anxiety?

The answer is that it needn’t. The technology to keep clothes looking new for longer is already in the detergents and fabric conditioners developed by scientists at P&G, one of the world’s leading consumer goods companies.

In a leafy campus in Brussels, some 600 scientists and engineers from 40 countries are developing and testing a new generation of fabric care products that are changing the way people think about their clothes and how they care for them.

At the heart of this is the smart chemistry in P&G’s detergents, like that in the Ariel Pod (above). These contain surfactants, long stringy molecules that bind to water at one end and oily substances at the other. Aided by agitation during a wash, these help to break up fatty

“ The new generation of detergents is improving the world, one wash at a time”

stains, lift them off fabric and lock them in the water ready to be rinsed away.

But other types of stains are more stubborn, some foods and body fluids for example. So detergents also include enzymes, biomolecules that can attack the offending grime. They include proteases that break down proteins, lipases that fragment fats and oils, as well as amylases that carve up carbohydrates.

Water is crucial for hydration but it can also hinder the cleaning process. Hard water, full of metal ions, can neutralise surfactants, so detergents usually contain water softeners, known as builders and chelating agents, which take metal ions out of circulation. Finally, special polymers keep dirt suspended during the wash cycle, helping to prevent redeposition and the greying of clothes this can cause.

Cool chemistry P&G’s detergents also contain “optical enhancers” that are deposited on fabrics making them look whiter and brighter.

Dr Neil Lant, a research fellow at P&G’s Newcastle Innovation Centre in the UK and his colleagues are on a mission to challenge what’s possible by designing detergents that deliver powerful stain removal and keep that T-shirt looking good too. “Detergents need to clean and keep clothes looking newer for longer,” he says. The team search for ways to make key ingredients work better in colder and quicker washes. For example, they have created an amylase which works at 15 °C. This involved P&G partnering with Danish biotech company Novozymes to redesign an existing enzyme that preferred higher temperatures.

ADVERTISING FEATURE

AGE PROTECTION The fabric conditioner Lenor makes clothes softer and smell fresher. But it has another crucial role, says Dr Renae Fossum, principal scientist at P&G’s Cincinnati Fabric and Home Care Innovation Center in Ohio. It protects garments against aging.

Lenor is relatively simple chemically.

It has a water-loving head atop a long, fatty tail. When dispersed in water, these molecules form spherical vesicles with the heads on the outside and the fatty tails inside.

“When the vesicles touch a fibre, they break and spread out to form a lubricating layer,” says Fossum.

This has multiple benefits. “It reduces the friction between fibres so they can return to their original positions more easily,” says Fossum.

This process helps garments keep their shape. It also stops fibres, especially cottons, from splitting and creating fuzz. And it maintains the colour vibrancy. That’s because much of the colour fade from washing isn’t the result of dye loss but increased scattering of light reflected from damaged and disordered fibres. This causes the fabric to look duller and lose its sheen.

Lenor combats this by helping to keep fibres smoother and aligned, so that light reflects uniformly from them.

This helps keep the colours bright and vivid. And it helps keep clothes looking new for longer.

COLOUR BOOSTER

Frederic Chapentier/GETTY

Unconditioned fibres reflect light haphazardly making colours dull

Smoother, conditioned fibres reflect light cleanly making colours more vibrant

The job of P&G’s researchers is complicated by trends in the fashion industry to use more synthetic fabrics. Since 1990, polyester has been replacing cotton as the most common clothing fibre because of its low cost and durability. More recently, the trend for figurehugging and sporty-looking casual clothes “athleisure” wear - has introduced more elastane, or Lycra®, into clothing.

“The big problem with these synthetics is that they are magnets for grime and bad odours,” says Lant. Anything oily sticks strongly to synthetic fibres, including the 20 grams of greasy sebum that an adult’s skin produces every day.

Elastane fibres are also prone to damage from limescale encrustations leading to a loss of “stretchiness”. Ariel’s advanced liquid formulas, with chelant technology, are designed to help prevent hard water mineral damage, a key cause of sagging.

It’s a wrap All this smart chemistry has to be carefully packaged. The latest of P&G’s detergents is the Ariel 3-in-1 pod, which delivers just 28 millilitres of detergent per wash, half the standard dose.

It took 8 years to create, yielded 50 patents and was tested on 8 tonnes of washing.

The pod is made of polyvinyl alcohol film, which is soluble in water. This must be strong enough to survive shipping, stable enough to survive months in storage and yet quick to dissolve in a washing machine. “That meant we needed a detergent with a low water content,” says Annick Vandeputte, senior scientist at P&G’s Brussels Innovation Center. “Less than 10 per cent of what’s in there is water.” The pod keeps ingredients apart in three chambers until the moment they combine in the wash.

The pods are a hit with consumers who want clothes to look new for longer and are easier for the less experienced, such as students, and for the elderly and visually impaired who may have trouble measuring out quantities.

There are other advantages too. An important goal for P&G is sustainability – a super compact pod uses less detergent for each wash and colder, quicker washes are better for your clothes and use less energy too.

For Lant, Vandeputte and their colleagues, that’s important: their new generation of detergents is improving the world, one wash at a time. And keeping your T-shirts looking newer for longer. n More at: www.pg.co.uk

ANALYSIS NORTH KOREA

Ready for launch?

IT HAS been a record year for “It is very likely that North North Korea’s nuclear ambitions.

Korea has a nuclear weapon that The secretive nation tested its could hit South Korea or Japan,” fifth nuclear device last month, says Joe Cirincione of the the second test this year and the Ploughshares Foundation, a US largest so far. Remote monitoring think tank. It may soon even be put the underground explosion at able to hit the continental US, 10 to 15 kilotons, about the size of making North Korea a top priority the Hiroshima bomb. Days later, it for the incoming US president. conducted its biggest-ever test of a How can we tell the North’s true long-range rocket booster. capabilities, given its secrecy?

“The threat has now reached a dimension altogether different “It is very likely that North Korea has a nuclear from what has transpired until weapon that could hit now,” Japanese prime minister South Korea or Japan” Shinzo Abe told the UN after the nuclear test. “We must thwart North Korea’s plans.”

While seismographs record the But how? The North has several explosive power of a bomb, there times agreed to limit its nuclear is no way to confirm its physical plans in return for aid or security size, but we do have clues. guarantees, but these deals have First, we can look to history. always fallen apart. Now the fear is The nation is at a significant point it won’t give up its nukes – unless in its nuclear development, says it collapses, which could be worse. Jeffrey Lewis at the Middlebury Before Kim Jong-un became Institute of International Studies leader in 2011, the nation’s nuclear in Monterey, California. The US, threat seemed constrained. “It UK, China, Russia and France had had limited fissile materials and all shrunk their warheads by their nuclear tests,” says Siegfried fifth tests. North Korea should Hecker at Stanford University in have made similar progress.

California, and no way to launch.

The nuclear material used Kim accelerated development can also hint at its size. Outside (see timeline, below) and the observers think the last two tests country now claims it can fit were fission bombs boosted by nuclear warheads on missiles. hydrogen isotopes. These release

neutrons in a thermonuclear reaction that produces more explosive force per kilogram of fissile material, usually enriched uranium or plutonium. Satellite images confirm that a plant visited in earlier inspections, which could be used to make the required isotopes, is now finished.

The North’s early tests released radioisotopes that could be detected remotely. These showed they were plutonium devices.

Hecker, who has visited North Korea’s main nuclear facility in Yongbyon, says it probably has enough plutonium for six to eight bombs and produces another bomb’s worth per year.

North Korea also has uranium.

Based on satellite images and a 2010 visit to its enrichment plant, Hecker calculates that it has 400 kilograms of highly enriched uranium (HEU), 16 bombs’ worth, and can add six bombs per year.

Smaller warheads The recent underground tests vented no material, so we don’t know what the devices were made of. But descriptions of a warhead released by the country in March suggest it is using nested shells of plutonium, HEU and hydrogen

JEON HEON-KYUN / EPA/CAMERA PRESS

How much should we worry about Kim Jong-un’s nuclear plans and what can we do to stop them, asks Debora MacKenzie

isotopes, says Lewis. “Britain used just such a design in its fifth nuclear test,” he says.

This design allows for smaller warheads, and hence more of them. David Albright at the Institute for Science and International Security in Washington DC calculates that Kim now has 12 to 20 nuclear weapons at his disposal. By 2020, North Korea could have 50 to 100, he says, and could field a crude thermonuclear weapon with a yield approaching 100 kilotons.

Who could it target? This year saw tests of conventional missiles launched from land and submarine that reached Japanese

North Korea’s nuclear path The nation’s nuclear programme has developed over the past three decades, but has recently accelerated to make 2016 a record year

Failed Known missile tests (incomplete) Nuclear tests (kilotons) Satellite launch 18 | NewScientist | 8 October 2016

US relations break down. Ejects inspectors and resumes plutonium production

<1 kt Failed

UN Security Council expands sanctions

2 kt Failed

Talks cancelled when US president George W. Bush calls it an outpost of tyranny

2010

UN Security Council imposes limited sanctions. Talks resume with US and others

2000

Leaves Nuclear Non-Proliferation Treaty

1990

Agreed Framework signed with US

1980

Nuclear facility built at Yongbyon

6-7 kt 2 Failed

4-6 kt 10-15 kt Success

Kim Jong-un takes over

For daily news stories, visit newscientist.com/news

waters – and could fly further.

These short-range missiles could carry warheads that weigh between 700 kilograms and a ton.

To hit the US, it needs a lighter warhead, a way to slow it down in flight and heat shields for reentry. Photos released by North Korea in March showed tests of a heat shield and in April it showed off a stationary test of the KN-08, a copy of a Soviet intercontinental ballistic missile (ICBM). This could launch a 500 kg warhead as far as Washington DC, says John Schilling of Aerospace Corporation in California. Flight tests might be only a year away.

But North Korea is unlikely to nuke the US, given the chances of a devastating response. Lewis says it only wants ICBMs to deter the US from striking first, as the mobile KN-08 would survive to retaliate.

The North is more likely to aim shorter-range weapons at the ports and airports needed to bring in US troops to defend South Korea, he says: “The goal for the leadership is survival, and if troops move in they have nothing to lose.” South Korea has missile defence, but it is only partial.

ultimately failed.” enforcement of sanctions is In 1994, North Korea and the US crucial – and it is unlikely to hurt signed the Agreed Framework.

North Korea enough to force The North pledged to give up its concessions, for fear the regime spent fuel, accept inspectors and might collapse. stop plutonium production in “Beijing doesn’t like a nuclear return for nuclear power plants North Korea on its border,” says that make less plutonium. The US Lewis. “But it certainly doesn’t promised no nuclear strikes and want a collapsed nuclear state.” to phase out sanctions.

So what can be done? It might “It’s the best deal we could have help if Pyongyang felt less gotten, and we lost it,” says Lewis, threatened, an approach that as George W. Bush took a tougher line. Sanctions remained, the new “There must be talks. power plants were delayed, and in They may not work, but what we have now is 2002 the US accused North Korea guaranteed to fail” of secretly enriching uranium.

The year after, North Korea left the agreement, and the Nuclear helped South Africa give up its Non-Proliferation Treaty. nukes in 1989. Last month, North Since then talks have repeatedly Korea’s foreign minister Ri Yong restarted only to be scuppered by Ho said they had “no other choice the North’s reactions to perceived but to go nuclear”, given annual aggression, including satellite US and South Korean military –Stop the bomb- launches condemned by the UN exercises “aimed at... the as banned missile tests (see occupation of Pyongyang”.

How do we stop all this? “There “Missile to the moon”, below).

It’s not just paranoia. South must be talks,” says Joel Wit at Now the US will talk only if Korea uses a mock-up of Kim JongColumbia University in New York. North Korea agrees to freeze its un’s palace for target practice, “They may not work, but what we programme. The North refuses. and the US has flown a nuclearhave now is guaranteed to fail.”

That leaves just trade sanctions capable bomber near its border.

Talks almost worked before. to put pressure on the nation.

Confronting North Korea in “There have been several efforts Both Donald Trump and Hillary this way is more likely to make that have successfully delayed Clinton want to tighten these. But a conflict go nuclear, says Van North Korea’s nuclear progress,” nearly all North Korea’s foreign Jackson at the Asia Pacific Centre says Albright. “But they business goes via China, whose for Security Studies in Honolulu.

Instead, the US and others should de-emphasise nukes in their MISSILE TO THE MOON deterrence, giving North Korea’s North Korea’s declaration in August But now, he says, space and leadership greater security. that it intends to put its flag on the missile development have parted That will be impossible if South moon was greeted with derision. ways. North Korea’s Unha-3 launcher Korea or Japan get their own Experts say their rocket could get has upper stages with small engines nuclear weapons. Domestic there, but a lander is beyond their perfect for putting a satellite in orbit, pressure to do that is growing, current technology. but too weak for an intercontinental and Trump backs a nuclear Japan.

Still, the nation looks determined, ballistic missile (ICBM).

Philip Jun of the Ploughshares attempting satellite launches despite Foundation fears that a military accusations that they are a front for COVERT OPS miscalculation – say a North missile development.

Yet the North’s space ambitions can Korean missile test wildly off Are they? Every nation with a also further its military ones. To make course – could make the heavily space programme once used a nuclear ICBM, the country needs a armed peninsula explode. launchers that doubled as missiles, heat shield to protect the warhead on Despite their spotted history, and China still does, says John re-entry. They could test one talks seem the only option. “No Schilling of Aerospace Corporation covertly, suggests Schilling, by flying country has ever been coerced in California. He thinks North Korea’s it on a “satellite” which falls to Earth. into giving up nuclear weapons, space programme taught it about We could soon see. North Korea but many have been convinced the multi-stage rockets it needs for just tested a larger booster engine to,” says Cirincione. None of them, long-range nuclear weapons. that may launch later this year. however, were rogue states that already had nukes. n 8 October 2016 | NewScientist | 19

comment

Going out on a limb When it comes to a Brexit deal, the science of strategic thinking suggests delay is the UK’s strongest hand, says Petros Sekeris PRIME Minister Theresa May has said she will trigger Article 50 of the European Constitution by next April to begin the UK’s exit from the European Union. This will set a two-year clock ticking for talks to finalise withdrawal.

Has she made the right decision? While we can try to answer that in many ways, game theory is science’s best bet. This mathematical construction of behaviour tries to predict how opposing sides in strategic settings will act to maximise the chance of achieving their goals.

It relies on three key inputs: who’s playing, their goals and when decisions can be made.

As far as the who goes, this is not just about the UK interacting with a single European block.

Instead, politicians from all 28 EU nations are motivated by domestic concerns. UK elections are due in May 2020. Across the

English Channel, 27 governments will influence talks to varying degrees, but France and Germany are the dominant powers.

The UK has conflicting goals: restricting movement of people while keeping trade open. The Brexit campaign’s immigration focus means May’s mission is to get a face-saving agreement on this while keeping trade tarifffree. The votes of Bremainers may be vital for her re-election hopes in 2020, many working in sectors at risk if trade barriers go up.

For the EU, free trade without freedom of movement has been a red line, and it also wants to deter more nations from quitting by ensuring an economic cost to Brexit. Plug these factors into the equation and it looks like an insoluble stand-off.

What about the when factor?

Game theorists have long known delaying tactics can be potent in

Sting in the tail If insects have feelings, do we need more humane fly spray, wonders Peter Singer YOU might want to think twice next time you reach for the fly spray. A willingness to draw parallels between mammals and insects is raising significant ethical questions about how we ought to treat them.

In May, researchers in Sydney, Australia, suggested that the main part of the insect nervous system 20 | NewScientist | 8 October 2016

works in a similar way to a mammal’s midbrain, and might provide the capacity for the most basic form of consciousness, subjective experience.

Now a group in London says that bumblebees appear to show “positive emotion-like states” (see page 9). Their study cites other papers from the past five

years that indicate a growing acceptance that invertebrates may show basic forms of emotion.

This is not so surprising, given evidence of intelligence in cephalopods such as the octopus.

But to grant insects emotions opens a whole new can of worms.

The authors say that emotional states in bees are not necessarily conscious, but could be. In ethical terms, consciousness – and hence the capacity to suffer – is crucial.

Rules to protect lab animals are

“If insects share the capacity for suffering, they too should be covered by lab animal regulations”

typically limited to vertebrates because there is little doubt that they can suffer. In the UK, the common octopus won protection in 1993, and later the EU included all cephalopods. If insects, or at least some, share a capacity for suffering, that would mean they too should be covered.

This would raise questions about the ethics of bee research. In one experiment, “aversive stimuli” were used: bees were temporarily trapped in a device to mimic being caught by a spider. If bees are capable of feeling fear, then presumably this was distressing – in which case, was the finding important enough to justify that?

For more opinion articles, visit newscientist.com/opinion

Petros Sekeris is a game theorist at Montpellier Business School, France

But if bees do have this type of consciousness, that might not mean that all insects do. We may hope that mosquitoes, flies and ants don’t, so we can get rid of them without worrying about inflicting pain.

And being capable of suffering would not grant insects a right to life. What it would mean is that we should reconsider how we stop them biting us or contaminating food, so we minimise any pain we may cause. n Peter Singer is professor of bioethics at Princeton University. Ethics in the Real World, a selection of his essays, is out now (Princeton University Press)

INSIGHT Colonising Mars

Bloomberg via Getty Images

the right circumstances, and everything suggests that this is the right approach here. Invoking Article 50 immediately would have put the UK in a weak position, because Europe needs to be tough in the face of the threat of rising right-wing extremism.

So when is the optimum date to trigger Article 50? In mid-2019, EU parliamentary elections will take place and EU budgets will be decided by the Commission.

While in the EU, the UK has a veto over the budget, and 10 per cent of the European Parliament’s MEPs. Still being “in” Europe then would win the UK added leverage.

There is also the chance that positions in France and Germany will soften after elections – in spring and early autumn 2017 – as the need to impress voters who want to see Brexit punished fades.

Invoking Article 50 should ideally be done no earlier than May 2017 to retain influence in EU elections and budget-setting and to be close enough to German and French elections to minimise their influence.

Will declaring Article 50 sooner, as Theresa May pledged, hit hopes of an optimal UK deal? All will be revealed by spring 2019. n

–Musk’s mission improbable–

SpaceX Mars plan is clever but unconvincing Lisa Grossman

His only mention of growing food on Mars assumed that we had already terraformed the planet. He was vague on how the settlers would generate energy. He said nothing about Martian dust, which covers solar panels and could harm astronauts.

When asked about health risks in transit, Musk suggested they would be minor. That runs counter to data from the Curiosity rover, which found that a round trip to Mars would expose astronauts to seven times the radiation dose they would get during six months on the International Space Station – well over NASA’s safety limits.

ELON MUSK has unveiled a spectacular plan to send humans to Mars, but I am not convinced he can really pull it off.

Last week at the International Astronautical Congress in Guadalajara, Mexico, the SpaceX founder laid out his vision for building the largest rocket ever, to launch a 100-person spaceship on an 80-day trip to Mars.

Once at the Red Planet, the spaceship will land on its feet using retro-rockets, and the astronauts will emerge on to a cold, dusty world.

Meanwhile, the spaceship will make its own methane fuel for a return journey to pick up more settlers. Musk “Spend your life savings on a one-way cruise, followed also plans to send supplies to Mars by a lifetime of physical every two years, starting in 2018. labour? Sign me up” Much of this strikes me as clever and innovative, but it may not be enough. Musk wants to send the first It may be that none of these issues humans in roughly 2024, although he are showstoppers for SpaceX. But was “intentionally a bit fuzzy about equally they seem not to be the first this timeline”. That only gives SpaceX problems on Musk’s list. And that’s odd, three chances to launch enough kit. considering his Mars colony is meant This is where the plan breaks down. to be humanity’s back-up plan.

Musk seems to think his job stops once “The thing that Mars really people reach Mars, and that keeping represents is life insurance, ensuring them alive is someone else’s problem. that the light of consciousness is not

extinguished, backing up the biosphere,” he said. “It’s not about everybody moving to Mars, it’s about becoming multiplanetary.”

So who will found this brave new world? The rich. Musk hopes to get the cost of a ticket to Mars down to around $200,000 and described the trip as a luxury cruise, with restaurants, movies and zero-G games.

But life on the Red Planet will be much less cushy: “Mars will have a labour shortage for a long time so jobs will not be in short supply,” he said.

So, you spend your life savings on a one-way Musk cruise, followed by a lifetime of physical labour on a cold, airless desert? Sign me up.

That’s not Musk’s vision, of course.

SpaceX’s video of the plan ends with Mars quickly growing more blue and lush, as if by magic. But if we are going to assume future magical terraforming powers, I would rather we apply them to the one planet we can already live on, and keep Earth habitable.

And who will pay for all of this?

Musk said the initial mission will cost around $10 billion, and wants backers for a public-private partnership.

Still, even talking about sending humans to Mars in a semi-realistic way is thrilling. Musk is highly driven and while vague, his plan is not impossible.

I doubt he will keep to that 2024 timeline, though. Musk himself admits that staying on schedule is not his forte. Even his talk started half an hour late. n 8 October 2016 | NewScientist | 21

Technology

It’s just common sense PONG is a gloriously simple video game: you control one paddle, aiming to bounce the ball past your opponent’s paddle. Artificial intelligence has learned to play it so well that it can easily beat human players. But try to get the same AI to play Breakout, a very similar paddle-based game, and it is utterly stumped. It can’t reuse what it has learned about paddles and balls from Pong, and has to learn to play from scratch.

This problem dogs modern artificial intelligence. Computers can learn without our guidance, but the knowledge they acquire is

“ A computer is like a child who learns to drink from a bottle but cannot imagine how to drink from a cup” meaningless beyond the problem they are set. They are like a child who, having learned to drink from a bottle, cannot even begin to imagine how to drink from a cup.

At Imperial College London, Murray Shanahan and colleagues are working on a way around this problem using an old, unfashionable technique called symbolic AI. “Basically this meant an engineer labelled everything for the AI,” says Shanahan. His idea is to combine this with modern machine learning.

Symbolic AI never took off, because manually describing everything quickly proved overwhelming. Modern AI has overcome that problem by using neural networks, which learn their own representations of the world around them. “They decide what is salient,” says Marta Garnelo, also at Imperial College.

Neural networks have delivered 22 | NewScientist | 8 October 2016

the big AI advances of recent times, but the representations they use are incomprehensible to humans and can’t be transferred to other neural nets. So for each fresh task, neural networks must build new ones. They learn slowly, relying on big data to chew on and plenty of processing power.

Shanahan’s work aims to tie symbolic AI to the autonomous learning of neural networks, allowing some knowledge to transfer between tasks. The prize is learning that is quick and requires less data about the world.

As Andrej Karpathy, a machine learning researcher with the firm Open AI, put it in a recent blog post: “I don’t have to actually experience crashing my car into a wall a few hundred times before I slowly start avoiding to do so.”

Symbolic AI also helps us understand how machines make decisions, something we often can’t do. “Neural networks don’t convert the reality around them into the kinds of symbols that we use,” says Joanna Bryson, an AI researcher at the University of

Bath, UK. By “symbols”, Bryson and other AI researchers mean any kind of reusable concepts or labels, such as words or phrases.

Shanahan and Garnelo’s hybrid architecture retains neural networks’ ability to interpret the world independently. However, the researchers combine that with some basic assumptions that reflect the way we understand the world: things don’t usually wink out of existence for no reason; objects tend to have certain attributes like colour and shape.

This allows the hybrid to build rudimentary common sense. “Our little system very quickly learns a set of rules,” says Shanahan. These let it handle unseen situations that are beyond a purely neuralnetwork-based system.

The team tested the hybrid’s abilities on a simple board game.

A mix between tic-tac-toe and Pacman, it features a cursor moving around a board littered with noughts and crosses. Hitting a 0 or × scores or loses a point respectively. Crucially, the distribution of the symbols is

conversational skills You’d be forgiven for thinking computers have language all figured

what you’re telling it. That’s a much higher-order problem, says Joanna

out. Google can translate between tens of tongues, and natural language processing lets us speak to software agents like Siri and Amazon’s Alexa.

But as Siri’s many noted missteps attest, a computer really has no idea what you’re talking about. It breaks your speech down, gloms on to keywords and makes a good guess at what you’re asking.

For a machine to carry on a real conversation, it must understand

Bryson at the University of Bath, UK, requiring an ability to understand symbols and meanings.

The power to fluidly describe, understand and interact with the world would bring us close to artificial general intelligence, something broadly acknowledged to be a distant prospect. Hybrid systems like the one being developed at Imperial College London may point to a way forward (see main story).

SM/AIUEO/Getty

To build a truly adaptable artificial intelligence, we first need to let it know how our world works, says Sally Adee

different every time, and the hybrid AI had to work out what actions were associated with reward. “If I go get that 0, that’s good. If I go get that ×, it’s bad,” says Shanahan.

When pitted against “Deep Q-Network” (DQN), an algorithm created by Google’s subsidiary DeepMind, the AI did extremely well, beating its score on randomly generated boards that neither architecture had seen before (arxiv.org/abs/1609.05518).

Crucially, the hybrid was able to transfer what it had learned across games. After 1000 training sessions, DQN managed a positive score on half of its games. But it took the hybrid only 200 sessions to arrive at a strategy that earned a positive score on 70 per cent of its games. Shanahan puts it down to it being able to port a rudimentary strategy across different games.

“I don’t want to hype this up

For more technology stories, visit newscientist.com/technology

Mobile 3D printer lets you make on the go YOU know the feeling: you look around and the one thing you urgently need seems to have vanished. Maybe it’s a key, or an earring back, or a specific spanner.

Whatever it is, a new project aims to help. With a mobile app and a pocket-sized 3D printer, this personal fabrication kit lets you quickly print what you need on the go.

For several years, 3D printing has

that could make these objects.

The most successful was a modified extruder pen, a kind of handheld printer that spits out a stream of plastic. An app lets you look up the object you want to make, then shows the pattern you need to trace on top of your phone screen to create it. In tests, the team printed a button for a shirt as well as a hex key to fit a loose bolt on a bike accessory.

been heralded as the next big thing in manufacturing. But Thijs Roumen, a graduate student at the Hasso Plattner Institute in Potsdam, Germany, wondered why it has yet to catch on for individuals.

He likens his vision for 3D printing to the rise of personal computing, where computers evolved from enormous machines into easy-to-use

The project will be presented at the User Interface Software and

handheld devices.

“We were curious why 3D printing never really made that transition,” he says. “What would the real world –It’s good to learn on the job– look like if we made things on the go, rather than in a controlled office

wouldn’t need to be learned.

In driverless cars, the symbolbased transparency of such a hybrid is also crucial. “Symbols are a really important aspect of how we explain ourselves and communicate with other people,” says Bryson. Coming legislation in Germany will require algorithms to explain decisions they take in driverless cars. By 2018, European Union citizens may have the right to ask any automated system to account for its decisions.

However, the most startling consequence of a workable hybrid architecture, Bryson points out, is that it could enable machines to convert their representations into reusable symbols – analogous to language or words (see “Conversational skills”, opposite).

“This experiment barely scratches the surface of what we believe is possible with this architecture,” Shanahan says. n

environment?”

First, Roumen and his colleagues crowdsourced a list of objects people wanted to be able to make when they were out and about, such as a karabiner to fix a broken strap or earplugs if someone were snoring beside them on the bus. Then the team built prototype mobile printers

B Christopher / Alamy Stock Photo

too much,” says Shanahan. “It is just a prototype. The game is simple, and the hybrid beat an old version of DQN.” Still, the implications of transferable learning are fairly significant. “Being able to pick up regularities at different levels is an important component of humanlike intelligence,” says Bryson.

This kind of hybrid learning is important for robotics. Powerful learning that involves many layers of neural networks is hard to apply there because of the volume of data needed, says Coline Devin, a computer scientist at the University of California, Berkeley.

Devin sees hybrid architectures as having a particular advantage for driverless cars. “They could use deep learning to process camera images,” she says, while accessing a library of preset rules – like stopping at red lights and carrying on when they are green – which

“This approach, where the human and the machine both do some stuff, can get a better result” Technology Symposium this month in Tokyo, Japan.

“I like this idea of moving entirely from the mechanised and automatic 3D printer to using a pen,” says Daniel Ashbrook at Rochester Institute of Technology in New York. The machine can balance human imprecision, while our motor skills offset the machine’s slow speed, he says.

“This kind of hybrid approach, where the human is doing some stuff and the machine is doing some stuff, can get a better result – especially when you’re not trying to be perfect, you’re just trying to get something done.” Aviva Rutkin n

–Parts when you really need them– 8 October 2016 | NewScientist | 23

Technology

ONE PER CENT

Plastic flower blossoms Material morphs to its own beat, finds Sandrine Ceurstemont

Sheiko et al. Nature Communications

State University in Pullman, who also develops transformable materials.

To create the material, Sheiko’s team tweaked the molecular structure of a conventional soft polymer. A small proportion of links between molecules in a polymer are permanent, allowing the material to act like a spring, snapping back to its original form when stretched and released, like a piece of rubber.

But most of the bonds are shape-shifting, breaking and rearranging themselves over time. It’s these that the team targeted: modifying the rate of shape-shifting let them control how the material changes over the course of several hours (Nature Communications, doi.org/bq8k).

“Most bonds snap in a split second, so our goal was to extend their lifetime,” says Sheiko.

Although the material can morph without an external trigger, the team found that tweaking pH and temperature gave them additional control to speed up or slow down the transformation.

Designing complex shapes proved difficult, so the team broke intricate designs into building blocks that could each be programmed to change at different times.

Programming the material to change at a constant rate was easy. But the team struggled to introduce a dormant period or to accelerate change at certain times.

Their best solution was to give an object an extra water-soluble “skin”. By tweaking its thickness based on the desired time delay, an additional clock could be added to the system when it was dropped into water.

“We plan to explore this –Let’s do the time warp again– further,” says Sheiko. n

24 | NewScientist | 8 October 2016

See dog-bot bounce Fancy a robot pet? Minitaur, the robotic dog, can climb stairs and chain-link fences, cross obstaclestrewn terrain and even reach up to open doors. Made by Philadelphia-based start-up Ghost Robotics, its motors act as both sensors and a spring system so Minitaur is bouncy, although its legs are rigid. The current version weighs 6 kilograms and has a maximum speed of 2 metres a second.

“We want to ban these small, virtual animals” The Dutch resort of Kijkduin makes its position clear as it takes the creators of Pokemon Go to court in an attempt to keep Pokemon players off protected beaches.

Electric tongue Move over sommeliers. An electronic tongue has been developed that can determine the age, type and quality of wine. Made by Xavier Ceto and colleagues at the University of South Australia, the device measures the electrochemical signals of compounds present in a wine, then converts them into a unique fingerprint for each. The goal is to use the device to test the quality of wines on an industrial scale.

Ghost Robotics

IT’S blooming marvellous. An permissible or are ineffective,” artificial flower can blossom when says Sheiko. “You simply want you want, thanks to petals made an object to change shape at a out of a material that contains its given moment.” own version of a biological clock.

So Sheiko and his colleagues “Nobody has ever done this have created a type of putty with before,” says Sergei Sheiko at the an internal clock that allows it to University of North Carolina at transform over time. They made Chapel Hill. the flower out of individually Morphing materials are “Morphing materials could interesting because they allow be used to create medical objects to change shape, and implants that change thus function. They have been mooted as a way to create medical shape inside the body” implants that are folded up for insertion into the body then programmed petals to change shape once inside. But demonstrate the concept, they typically need a trigger to alongside a box that opened on start the process, like a change in one side at a scheduled time. light levels, temperature or pH. “It has great potential for a “In certain situations, like range of applications, especially inside your body or in space, in biomedical engineering,” says external triggers are not Michael Kessler at Washington

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Aperture

26 | NewScientist | 8 00October Month 2016

Beautiful sludge SINUOUS red streams of aluminium-processing waste and bright green vegetation light up this aerial view of an industrial reservoir on the lower Mississippi river, about 50 kilometres south of Baton Rouge. At first glance, the vivid colours suggest beauty, but the image is meant to cause alarm, says photographer J. Henry Fair.

Producing aluminium from bauxite ore generates a toxic sludge called “red mud” that is visible around the edges of the football-fieldsized area pictured here. When a similar reservoir containing the substance burst in Hungary in 2010, four people were killed and there was catastrophic ecological damage.

Fair wants to get us to think about what we choose to buy and throw away, as well as the environmental impact of something as simple as failing to recycle an aluminium can.

“The pictures are an effort to show these things to people in a way that makes them question, and hopefully think about, the impact,” he says.

The photograph below is another bird’s-eye view, this time of a field in Germany. The shadows cast by surrounding trees have stopped some of the rapeseed plants from flowering.

Both images are part of a series taken over 15 years from a small plane and collected in the book Industrial Scars, published by Papadakis this week. Emily Benson

Photographer J. Henry Fair jhenryfair.com/aerial

8 00 October Month 2016 | NewScientist | 27

COVER STORY

Going clean Crack a simple chemical reaction and we don’t have to kick our addiction to fossil fuels, says Jon Cartwright

Jack hudson

S

CARRED landscapes, billowing smoke, seabirds writhing in liquorice gloop: there’s no denying fossil fuels have an image problem. That’s before we even start to factor in the grave risk continuing to burn them poses to Earth’s climate. But what’s the alternative? Nuclear is expensive, renewables are unreliable, and we are a long way from making batteries that could power our fuelhungry lifestyles. Realistically, we are going to be reliant on fossil fuels for a while yet.

What we need is a way to exploit them without emitting any planet-warming carbon dioxide. Alberto Abánades thinks he has the answer. He isn’t a PR man for the fossil fuel industry, and nor does he have anything to do with various schemes to capture and bury carbon emissions after the event. He and his research team think they have cracked the problem using chemistry alone. By simply changing the way we liberate the energy trapped inside natural gas molecules, we can have all the benefits of fossil fuels – and none of the guilt. Too good to be true?

It’s easy to see why we love fossil fuels.

For a start, they are cheap and abundant.

Discoveries of new resources and extraction techniques such as fracking mean reports of “peak oil” always seem exaggerated. They are reliable, too – you can shovel coal or pipe gas into a power station when the sky is cloudy or the wind’s not blowing. And they can be portable – simply fill a car tank with petrol and you are good to go.

28 | NewScientist | 8 October 2016

We have tried to kick our fossil addiction before. During the oil crisis of the 1970s, all the talk was of hydrogen. The gas ticks a lot of boxes as a fuel: it is non-toxic and the most abundant element in the universe. It is clean, burning in air to create water vapour that falls harmlessly back to Earth as rain. It is energy-dense – you could drive the 600-odd kilometres from London to Edinburgh, or San Francisco to Los Angeles on a single tank.

And it can be burned in power plants, even competing cost-wise with fossil fuels once carbon taxes are taken into account.

“ It’s easy to see why we love fossil fuels – they’re cheap, abundant and reliable” In practice, things aren’t so simple. Being light and tiny, hydrogen has an annoying ability to wiggle through any material designed to contain it. Like petrol, it is flammable, yet burns with a near-invisible flame. Above all, it isn’t abundant where and how we want it.

On Earth, hydrogen isn’t a free agent. It is only found bound up in compounds such as water. Pure hydrogen can be generated by splitting water molecules using electrolysis, but that takes a lot of energy. Or you can extract hydrogen from coal or natural gas by heating them with steam, but that generates copious amounts of carbon dioxide.

So it came as little surprise when, in 2009, then US energy secretary Steven Chu, a Nobel prizewinning physicist, ditched funding for research into hydrogen-powered vehicles.

Last year, Elon Musk, CEO of electric-vehicle manufacturer Tesla, summed up many sceptical opinions when he labelled hydrogen an “incredibly dumb” alternative fuel.

Perhaps, though, we haven’t been thinking about it in the right way. Natural gas is essentially methane, a molecule of one carbon atom and four hydrogen atoms. Rather than reacting natural gas with steam to liberate the hydrogen, Abánades, who is now at the Technical University of Madrid, and his team developed a deceptively simple plan.

You “crack” the methane into its constituent atoms – pure, clean hydrogen, plus inert atomic carbon, or soot.

If it were that simple, it would already have been done. Breaking carbon-hydrogen bonds takes a lot of energy. They only start to crack spontaneously at temperatures above 550 °C or so; normally, temperatures over 800 °C are needed. But there is a bigger problem: the soot. This scuppered an early attempt to make methane cracking industrially viable: it coated the nickel-iron-cobalt catalyst used by chemists at the petroleum company Universal Oil Products to improve the reaction rate at lower temperatures. Their solution was to burn off the carbon – making carbon dioxide.

It’s been the same lament with methane cracking ever since. Soot clogs things up and >

8 October 2016 | NewScientist | 29

Booze cruise It is inherently difficult to compress flighty hydrogen

gas. It is much easier to create by combining hydrogen

There are other options. In 2014, scientists at the Swiss

gas into a fuel tank. The problem evaporates if you first convert it into a liquid alcohol, such as methanol.

Aside from being easy to store, methanol can be used in regular internal combustion engines – where it can even perform better than petrol.

Compared with methane, methanol contains just an extra oxygen atom, but it is tricky to make from natural

with carbon dioxide. The combustion of methanol in an engine releases carbon dioxide into the atmosphere, but if you use atmospheric carbon dioxide in the first place, the overall process is carbon-neutral. Eric Croiset at the University of Waterloo in Canada is hoping to work with a company to build a proto-plant that generates methanol in this way.

Federal Institute of Technology in Lausanne reported a straightforward process for converting hydrogen into formic acid that can be fed into fuel cells, the battery-like power systems that drive hydrogen vehicles.

The process is also reversible, so formic acid could be an alternative way to squirrel away hydrogen when regular storage is impractical.

the whole process grinds to a standstill. It’s inevitable: the carbon has to go somewhere.

In his 20 years as an engineer, Abánades has worked on various types of energy generation, including nuclear and solar. His old group leader, Carlo Rubbia, first put him on to methane cracking in 2008. Rubbia had shared the Nobel prize for physics in 1984 for his part in finding the particles that govern nuclear decay, but, in his late seventies, he had long since turned his focus to energy innovation.

“Professor Rubbia has always said to me, don’t do what others do,” says Abánades.

a vessel about the height and diameter of a hockey stick lined with quartz glass and stainless steel and filled with molten tin. Its external foil insulation made it look rather like a domestic hot water tank but it worked: they bubbled methane in at the bottom while raising the temperature of the tin up to 1000 °C, until hydrogen gas spouted continuously from the top.

But the real test was what it looked like inside. After two weeks, Abánades and colleagues switched off the reactor and peered in. Soot had indeed formed, but it had all floated neatly to the tin’s surface, where it could be scraped away like the slag in an ore refinery. “We could even have operated the reactor for a couple more days,” says Abánades.

Last year, repeating the experiment at 1200 °C,

Bubble bath

30 | NewScientist | 8 October 2016

Clean hydrogen could transform our energy and crop production

Nicolas Loran/Getty

Trawling back through the literature, they soon found something someone hadn’t done.

Back in 1999, Meyer Steinberg, a chemical engineer at Brookhaven National Laboratory in New York, and a veteran of the Manhattan Project to make a nuclear fission bomb, had proposed performing methane cracking in a heat bath made of molten metal. The idea, apparently never acted upon, was that the molten metal would improve heat transfer and allow the soot to float to the surface, avoiding clogging.

Abánades and Rubbia were then based at the Institute for Advanced Sustainability Studies in Potsdam, Germany. On the other side of the country, at the Karlsruhe Institute of Technology, was perhaps the best molten metal laboratory in Europe. By 2012 the two groups were collaborating on a 30-month fast-track project to see whether they could, well, crack methane cracking.

After two years of trial and error, they had what they thought was a viable reactor design:

the team managed to convert nearly 80 per cent of the methane they pumped in into hydrogen (International Journal of Hydrogen Energy, vol 41, p 8159).

The notion that hydrogen can be continuously generated from methane, without directly producing any greenhouse gases, is enough to turn the heads of those in the field. “These are serious people,” says Eric Croiset, a chemical engineer at the University of Waterloo in Canada, who performed a review of the state of methane cracking five years ago. “I wouldn’t distrust their results.”

We haven’t reached the promised land yet, though. To heat their reactor, Abánades’s team resorted to electricity from the wall socket – not necessarily the green option. A renewable source of heat, such as a solar concentrator, might do the trick, says Stéphane Abanades (no relation) at the French solar innovation lab PROMES, although there’s a risk that when the sun sets or goes behind a cloud, the molten tin could solidify, damaging the reactor.

“Supplying solar energy to such a reactor may not be an easy task,” he says.

Alberto Abánades hopes that a future reactor could simply burn a little of the hydrogen it generates, perhaps 15 per cent of the total yield. This approach would generate similar low levels of carbon dioxide as hydrogen produced by wind-powered electrolysis of water, but would be cheaper, more reliable and more scalable, according to his team’s preliminary analysis, performed in collaboration with RWTH Aachen University in Germany.

That still leaves the question of the soot.

Scaling up methane cracking to terawatt-scale production – a reasonable extrapolation for a global hydrogen economy – would create a mountain of soot several cubic kilometres in volume every year. That is far less problematic than the carbon dioxide generated by directly burning fossil fuels, but still not an amount you can brush under the carpet.

“ Other bits of the hydrogen puzzle seem to be coming together too” Abánades is confident a cheap and abundant supply of pure black carbon will find its uses, given the element is already in demand for nanotechnology, steel production and as a filling for car tyres. “A new market could be opened up,” he says. But first the carbon produced has to be of a higher quality.

The methane cracking team believes its carbon is about 90 per cent pure, and could be improved either by tinkering with the reactor’s chemistry or by purifying the carbon further down the line.

Is it full steam ahead for the hydrogen economy? Perhaps, especially as other bits of the puzzle seem to be coming together.

For example, chemists are tinkering with ways to convert hydrogen into fuels that are easier to handle, such as methanol (see “Booze cruise” left). That might sound convoluted, but Abánades points out that oil is just as useless when freshly drilled from the ground. “Do we actually use crude oil? No, we transform it into gasoline.

Hydrogen could be similar,” he says.

Spurred on by cheaper hydrogen technology and the current range limitations of batteries, Toyota, Hyundai and Honda have all recently put cars powered by hydrogen fuel cells back on sale. Last year the European Union launched the Hydrogen Mobility Europe project, aiming to create a network of hydrogen refuelling stations across Europe. The UK government is providing small subsidies for fleets of hydrogen-powered vehicles. Croiset believes electric and hydrogen cars could address different markets, perhaps electric for inner city travel and hydrogen for longer distance commuting. “You will buy the vehicle that suits your needs,” he says.

Others are less keen on the incentives that producing hydrogen-based fuels from natural gas create. The technology could commit us to

The reaction that feeds the world Should the futuristic hydrogen economy fail to materialise (see main story), hydrogen from methane cracking has a market ready and waiting: ammonium fertiliser. The Haber-Bosch process, which converts hydrogen and nitrogen into ammonia, generates most of the ammonium fertiliser used in agriculture.

The reaction has been credited with fuelling the 20th century’s population boom. It is so ubiquitous that it is part of you: over 80 per cent of the nitrogen that finds its way into the average person’s tissue is thought to be as a result of the Haber-Bosch process.

Currently over 95 per cent of hydrogen production comes from traditional fossil-fuelled processes, mostly blasting natural gas with steam. In 2007 alone, the fertiliser industry generated a little short of 500 million tonnes of carbon dioxide, nearly 1 per cent of total global emissions. Re-supplying the HaberBosch process with methane-cracked hydrogen could drastically shrink this carbon footprint. With the world population expected to exceed 10 billion by the end of this century, that would be a significant step on its own.

more fossil-fuel infrastructure in the future, distracting from efforts to pursue renewable alternatives, warns climate scientist Ilissa Ocko from the Environmental Defense Fund, a New York-based non-profit that campaigns on global warming. What’s more, the pipelines used to transport natural gas are known to leak a considerable amount of methane, a far more potent greenhouse gas than carbon dioxide. “Unless these leaks are plugged, it’s possible that the warming from leaked methane will offset the climate benefits from methane cracking in the near-term,” she says.

Abánades agrees that climate impact should be the deciding factor on which technologies to pursue. But in energy innovation, he says, it is tempting to view those working on different technologies as enemies, and it is easy to become tarnished by an association with fossil fuels. In the absence of a renewable silverbullet, anything that limits the impact of fossil fuels has to be a good thing, he says.

“Emissions should be stopped now, and that could be done through methane cracking.

If they aren’t, when it comes to controlling global warming, we will be too late.” n Jon Cartwright is a freelance journalist based in Bristol, UK 8 October 2016 | NewScientist | 31

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Are we really in the midst of an anxiety epidemic, asks Linda Geddes

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32 | NewScientist | 8 October 2016

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RUSSELL JOHNSON / EYEEM/GETTY

ost of us are familiar with the dry mouth, racing heart and knotted stomach that are the hallmarks of feeling anxious. Usually this is a fleeting response to danger and uncertainty. In some people, however, the state of high alert won’t switch off. Their anxiety becomes so draining it is impossible to leave the house or function in daily life.

One woman feels agitated and lightheaded each morning when she wakes.

She worries about the accidents that might befall her if she travels to work, but also about what would happen if she had nothing planned for the day. Another avoids work, friends or even walking her dog in case it triggers another panic attack. One man finds it difficult to pick up the phone for fear he will mash his words and be misunderstood.

These are real cases of people who have sought help for their anxiety. Their experiences aren’t unusual. Anxiety disorders – including generalised anxiety, panic attacks, social anxiety and phobias – are the most prevalent mental health problem in the US and Europe, and a growing number of reports from other regions suggest they could be a global concern. In the West, they cost healthcare systems more than $40 billion each year. On average 1 in 6 of us will contend with an anxiety disorder at some stage in our lives – women more than men.

The damage is real. Anxiety disorders have been linked to depression and increased substance abuse, particularly of alcohol. A recent study found that men who have anxiety disorders are twice as likely to die from cancer as men who don’t, even when factors such as drinking and smoking are taken into account.

So what is the cause of all this anxiety? Is there more of it about, and what is the best way to tackle it?

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HOW MUCH ANXIETY IS NORMAL?

ARE WE MORE ANXIOUS THAN WE USED TO BE?

Anxiety is a natural response that evolved over millions of years to make us more vigilant and prime our bodies to flee danger.

But feeling anxious because you heard a noise on a dark street isn’t the same thing as having an anxiety disorder. “The key thing we look for in the clinic is whether anxiety is interfering with a person’s day-to-day life, or causing them a lot of distress,” says Nick Grey of King’s College London.

To clinical psychologists like Grey, “maladaptive beliefs” are a hallmark of anxiety disorders and are often used to diagnose the type of anxiety someone has. In social anxiety disorder, the most common anxiety disorder, you might believe that blushing will result in people laughing at or shunning you. People with this type of disorder experience persistent and overwhelming fear before, during and after social events.

If you have panic disorder, you might assume that you are having a heart attack if your heart starts to race. The physical symptoms of anxiety – a pounding heart, difficulty breathing, feeling dizzy or flushed – will then come on in a rush. Everyone can experience such panic attacks from time to time, but in panic disorder the attacks are regular and become a source of anxiety themselves.

Other maladaptive beliefs are less specific.

Generalised anxiety disorder is characterised by chronic worrying about a range of different events or activities, for at least six months. If you have this condition, the belief driving your anxiety could, for example, be the feeling it’s your job to take care of other people, or that you have responsibilities that you must meet at all cost. To decide who to refer for further treatment, doctors might use a tool called the GAD7 test (see “Test your anxiety levels”, page 35).

The Greek philosopher Cicero was among the first to define anxiety as an illness, in the 1st century BC. Our current medical definition dates to 1980, when the American Psychological Association estimated that between 2 and 4 per cent of people in the US had an anxiety disorder. Today, some studies suggest it’s more like 18 per cent in the US and 14 per cent in Europe.

Such figures have led some to conclude we are in the midst of an anxiety epidemic, fuelled by factors such as economic anxiety, social media and the rise of the 24-hour society. The reality is more complex. The apparent increase is probably due to changes in diagnostics over the years, which make long-term comparisons difficult. “I think we are becoming more stressed and that has to do with having a lot of demands on our time,” says Jennifer Wild of the Oxford Centre for Anxiety Disorder and Trauma in the UK. “But if you’re looking at the prevalence of anxiety disorders, they haven’t gone up.”

There is tentative evidence to support this conclusion. For instance, Olivia Remes and her colleagues at the University of Cambridge found little overall change in the number of people around the world affected by anxiety disorders between 1990 and 2010. Their metaanalysis, published earlier this year, found that roughly 1 in 10 people experience anxiety at any given time, and about 17 per cent are likely to experience it at some stage in their lives.

Remes found that adults under the age of 35 were disproportionately affected by anxiety. Similarly, Borwin Bandelow and Sophie Michaelis at the University Medical Centre in Göttingen, Germany, found evidence that the prevalence of most anxiety disorders peaks in 18 to 34-year-olds before dropping off again. Specific phobias were the exception, peaking in 35 to 50-year-olds.

Even if the overall prevalence of anxiety disorders hasn’t increased, anecdotal evidence suggests that the type of anxiety people are experiencing is changing. When Nicky Lidbetter, chief executive of Anxiety UK, joined the charity 20 years ago, the majority of queries they received were from people with panic disorder or agoraphobia, an extreme fear of open spaces. “Nowadays it is health anxiety [hypochondria] and social anxiety,” she says. >

“ANXIETY DISORDERS ARE THE MOST PREVALENT MENTAL HEALTH PROBLEM IN THE WEST”

8 October 2016 | NewScientist | 33

ARE SOME PEOPLE NATURALLY MORE ANXIOUS THAN OTHERS?

Although we are still a long way from fully understanding what is going on in an anxious brain, recent studies offer some insights into why anxiety seems to take over in some people. Central to it all is the amygdala, a brain region that processes our emotions and triggers the release of the hormones responsible for the fight-or-flight response.

The amygdala is linked to parts of the prefrontal and anterior cingulate cortex that process social information and help us make decisions (see diagram, opposite). During bouts of everyday anxiety, this brain circuit switches on and then off again – but Oliver Robinson at University College London and his colleagues have shown that in people with anxiety disorders it seems to get stuck in the on position. “We think it might be amplifying negative information in your surroundings to make sure you pay attention to it, and triggering a fight-or-flight response so you’ll run away,” says Robinson.

Studies suggest that fear memories stored in the amygdala prime us to respond to threats we have previously experienced. This response is normally kept in check by a parallel circuit: in healthy people, inputs from the prefrontal cortex can temper our learned response and even overwrite it with new memories. Occasionally the system fails, however. Psychiatrists have found that war veterans with post-traumatic stress disorder – a kind of anxiety disorder – have abnormally low levels of activity in their prefrontal cortex, and unusually high levels in their amygdala.

Ultimately, an overactive amygdala appears to hype up the familiar symptoms of the fightor-flight response by stimulating a network of hormonal glands and brain regions called the “HPA axis” – causing rapid heart rate and breathing, a dry mouth, shaking and tense muscles. The fight-or-flight response also has less obvious effects, like slowing digestion and making us more susceptible to pain.

Understanding these interactions will help design better treatments. For instance, Robinson’s circuit switches on when levels of the neurotransmitter serotonin are low, which could explain why a class of antidepressants known as SSRIs can reduce anxiety levels: they increase the availability of serotonin in the brain. “Maybe serotonin is applying the brakes to this particular circuitry,” says Robinson.

Do you calmly navigate life’s bumps or agonise at every turn? Psychologists have long argued that people have innate dispositions that explain how we act, one of which is neuroticism – or proneness to anxiety.

A recent study of more than 106,000 people identified nine regions of the genome that seem to correlate with neuroticism. Some of these contain genes previously linked to anxious behaviour, such as CRHR1, which regulates release of the stress hormone cortisol. The same gene has also been associated with anxiety-related behaviour in mice, and panic disorder in humans.

Some people are therefore naturally more prone to anxiety. But even if you are a naturalborn neurotic, this doesn’t mean you will develop an anxiety disorder. “Having a high level of dispositional anxiety is a risk factor for developing an anxiety disorder, but you can be

34 | NewScientist | 8 October 2016

highly anxious and completely healthy,” says Marcus Munafo, a behavioural neuroscientist at the University of Bristol, UK. Your age (see “Are we more anxious than we used to be”, page 33) and sex are factors at play. Population studies show that women are about twice as likely to develop an anxiety disorder as men. In part, this may be down to hormones and their influence on the brain. The surges in oestrogen and progesterone that occur during pregnancy, for instance, have been linked to obsessive compulsive disorder, an anxiety-related condition. Remes points out that there may be other explanations too, such as the fact that women tend to cope with stressful situations differently. “They worry a lot more about what’s going to happen, which can increase their anxiety,” she says. “Men tend to take a more problem-focused approach.”

PHILIPPE LESPRIT/PICTURETANK

WHAT CAUSES THE SYMPTOMS OF ANXIETY?

“BEING A NATURAL-BORN NEUROTIC DOESN’T MEAN YOU’LL DEVELOP ANXIETY DISORDER”

WHAT’S THE BEST WAY TO TACKLE AN ANXIETY DISORDER? TEST YOUR ANXIETY LEVELS Doctors use the GAD-7 test to help them decide whether a person is experiencing pathological levels of anxiety. For each of the questions here, answer “not at all”, “several days”, “more than half the days” or “nearly every day”, giving yourself a score of 0, 1, 2, or 3 respectively.

See * below to interpret your total score.

Over the last two weeks, how often have you been bothered by any of the following problems: 1. Feeling nervous, anxious or on edge?

2. Not being able to stop or control worrying?

3. Worrying too much about different things?

4. Trouble relaxing?

5. Being so restless that it is hard to sit still?

6. Becoming easily annoyed or irritable?

7. Feeling afraid as if something awful might happen?

If you have an anxiety disorder, cognitive behavioural therapy (CBT) is likely to be the first recommended treatment. Considered the gold standard in treatment, it aims to address the maladaptive beliefs that drive your anxiety. Once they have been identified, CBT helps you challenge them. “If someone is worried about blushing, we might put blusher all over their face and make them have conversations with people to see that they generally don’t even notice,” says Wild. “For panic disorder, you might get someone to run up and down the stairs, to show them that even if they do an extreme behaviour, they aren’t going to have a heart attack.”

A shortage of therapists has spurred the development of online delivery of CBT. In a pilot study of 11 people with social anxiety disorder, Wild found that nine of them responded to online CBT and seven achieved remission,

The anxious anxious brain brain The The amygdala amygdala is is responsible responsible for for initiating initiating the the fight-or-flight fight-or-flight response. response. Two The Two circuits circuits feed feed into into it, it, one that enhances its activity and one that dampens it.

In people with anxiety disorders one that enhances its activity and one that dampens it. In people with anxiety disorders the the normal workings workings of of these these circuits circuits are are disturbed, disturbed, and and the the amygdala amygdala is is hyperactive normal hyperactive

PREFRONTAL PREFRONTAL CORTEX CORTEX Centre Centre for for rational, rational, logical logical thought. thought. It It is is involved in laying down new memories involved in laying down new memories and and tempering tempering learned learned fear fear responses responses

_ _ Tempers + Tempers anxiety anxiety Enhances anxiety anxiety + Enhances

PREFRONTAL PREFRONTAL AND AND ANTERIOR ANTERIOR CINGULATE CINGULATE CORTEX CORTEX Amplifies Amplifies negative negative information information in in your your surroundings and makes you pay surroundings and makes you pay attention attention to to it it

AMYGDALA AMYGDALA Emotional memories memories and Emotional and our our learned learned reactions reactions to to them them are are stored stored here. here. When When active, active, it it triggers triggers the the release release of of hormones hormones responsible for the fight-or-flight response responsible for the fight-or-flight response

_ _

+ +

Fight-or-flight Fight-or-flight response response (sweaty (sweaty palms, palms, racing racing heart heart etc) etc)

* SCORING THE GAD-7 TEST Scores of 5 to 9, 10 to 14, and 15 to 21 indicate mild, moderate and severe anxiety, respectively.

Doctors recommend further evaluation if your score is 10 or greater. This test is best suited to highlighting generalised anxiety disorder but may also help pick up panic disorder, social anxiety disorder and post-traumatic stress disorder.

COPY COPY SUB SUB

although it is too early to say if this is better or worse than face-to-face therapy.

Therapy isn’t for everyone, however. Some people don’t respond well to therapists or analysing their own behaviour. In this case, a second line of attack is drugs, which can redress chemical imbalances in the brain.

Several studies have shown that people with panic disorder and generalised anxiety disorder tend to have lower levels of a neurotransmitter called GABA, which is thought to help the amygdala filter out unthreatening stimuli. Blocking GABA production in rats has been shown to trigger anxiety-like symptoms.

Benzodiazepines, a class of common anti-anxiety drugs which includes Valium, work on this system but are highly addictive.

Doctors may feel more comfortable prescribing antidepressants, says Lidbetter.

These can help with the physiology of anxiety as well as the secondary symptoms, which often include depression. However, Lidbetter believes that this is a field that needs to move on. “We need a new benzodiazepine-type drug – something which isn’t addictive,” she says.

Exercise can help with day-to-day anxiety and is a helpful additional strategy for people with anxiety disorders. It triggers the release of mood-boosting endorphins, and forces you to concentrate on something other than your own thoughts. Then there’s diet. A team led by Phil Burnet at the University of Oxford has found that taking a fibre-rich supplement to encourage the growth of beneficial gut bacteria for three weeks caused people to pay more attention to positive words on a computer screen and less attention to negative ones. Upon waking each morning, the volunteers also had lower levels of the stress hormone cortisol in their blood.

“We saw a small but significant effect on the underlying psychological mechanisms that contribute to anxiety,” says Burnet.

Modern life may be packed with events outside your control, seemingly designed to foster anxiety and self-doubt. The important thing is to recognise the symptoms and do something about them. n Linda Geddes is a consultant for New Scientist. For links to the studies mentioned, see bit.ly/NSAnxiety 8 October 2016 | NewScientist | 35

All photos by Dave Sinai for New Scientist

The birth and death P of a language In a dusty village in the Negev desert, linguists are racing to decode a remarkable new language before it vanishes forever. Shira Rubin reports

36 | NewScientist | 8 October 2016

AST the glimmering industrial developments and fast food chains of the northern Negev desert in Israel, I pull off the dusty highway into the quiet village of Al-Sayyid. A family of 22 awaits me outside their home, greeting me with sage tea. The children introduce me to the family pets: a horse, a brood of chickens and a camel. Meanwhile, the head of the household, Ishak al-Sayyid, recounts his family’s history, shifting between Arabic, Hebrew and a language I don’t understand.

Ishak’s family have lived here for generations. They are members of the Al-Sayyid Bedouin tribe, founded 200 years ago by an Egyptian peasant who moved here after a family feud then married several local women. Shaykh al-Sayyid’s children married among themselves after being rejected as outsiders by neighbouring tribes. What they did not know was that two of them carried a recessive gene for congenital deafness.

Intermarriage became the norm in the village, and the gene spread. The first deaf

children were born in the 1930s. At first it was just one family, with four deaf siblings among many hearing ones. But soon other families started having deaf children too. Today the village has the highest known rate of congenital deafness in the world. Around 150 of 4000 residents were born deaf, 50 times the global average. Three of Ishak’s own children are deaf.

Deafness also accounts for what really puts Al-Sayyid on the map. Over the past 75 years, the villagers have created an entirely new and unique language, Al-Sayyid Bedouin Sign Language (ABSL). The seeds emerged spontaneously among the first deaf residents and, three generations later, it has flowered into a complex language capable of expressing anything a spoken one can.

Since its discovery by linguists in 2000, ABSL has captivated researchers driven by two fundamental questions: how did language emerge, and what can that tell us about the nature of the human mind?

More than 15 years and hundreds of hours of video footage later, those researchers have documented a remarkable language that casts serious doubts on some long-standing linguistic theories. But even as they decipher ABSL’s secrets, it is in danger of dying out.

fully fledged languages, with a rich vocabulary and formal grammar.

This is probably how most of the world’s 140 or so major sign languages started life.

The beauty of ABSL is that it is emerging right now, in front of linguists’ eyes. “We can literally see it unfold,” says Wendy Sandler at the University of Haifa, Israel, who launched the ABSL study.

ABSL has other features that make it especially appealing. Unlike other village signs studied so far, it apparently emerged uninfluenced by the other languages used in the village today – modern Arabic, the local Bedouin dialect, Hebrew and Israeli Sign

Forbidden experiment The origins of language have always fascinated us. Around 3000 years ago, the Egyptian pharaoh Psammetichus was said to have plucked twin infants from their mother and turned them over to be raised in isolation by a shepherd who was forbidden from speaking in their presence. The idea was that whatever words the babies produced would reveal the original, primal form of human language.

Linguists refer to this as the “forbidden experiment”. Obviously they cannot replicate it, but sign languages like ABSL offer something very similar.

ABSL is classed as a “village sign”, a type of language that often emerges in isolated communities with large numbers of deaf people. One of the earliest known arose in the 18th century on Martha’s Vineyard, an island off Cape Cod, Massachusetts. The language was widely shared by both deaf and hearing people, but rose and fell without being formally documented.

Today at least 24 village sign languages exist across the globe. They usually start life as a “home sign” – a set of rudimentary gestures invented by two or three people in the same household. But in the hands of a community of deaf people, they can rapidly evolve into

Salah al-Sayyid tells a story using the signs “man”, “soldier” and “papers”

Language. That makes it possibly the purest sign language ever recorded – a pristine expression of the human instinct to converse.

In addition, the deafness gene does not cause any physical or mental disabilities and deafness is not stigmatised in Al-Sayyid, so deaf people are fully integrated into society.

Both deaf and hearing members of the community are fluent signers. During my visit, I spoke with a group of boys playing soccer on a dusty courtyard. The hearing kids immediately translated into ABSL so that all could participate in the conversation.

ABSL thus offers a unique opportunity to test a theory that has dominated linguistics since the 1950s. Put forth by Noam Chomsky, it claims that language is an innate and uniquely human trait, programmed into our genes.

Children are born with a “language instinct” that compels them to effortlessly acquire whatever language (or languages) they are immersed in as toddlers.

Chomsky also proposed the idea of a “universal grammar” shared by all languages.

He said that a Martian visitor to Earth would find that, apart from their mutually unintelligible vocabularies, “Earthlings speak a single language.” Thus began the search for deep structures common to human languages across cultures.

That is what makes village signs like ABSL so fascinating. If Chomsky is right, their spontaneous emergence and evolution ought to reveal the language instinct at work, as home signers invent a rudimentary language from scratch and their children and children’s children convert it into a fullblown language.

As predicted, ABSL started to evolve a grammar in its second generation of signers.

In 2005 Sandler’s team reported that one of the most important organising principles of any language – the word order in a sentence – appeared to be settling on a rule called subject-object-verb (S-O-V; “I ball kick”).

That was a tantalising result. For one thing, Arabic and Hebrew use a different word order (S-V-O; “I kick ball”), bolstering the case for ABSL’s linguistic independence (though Israeli Sign Language uses S-O-V very occasionally, which muddies the water a bit).

More importantly, S-O-V has an important place in universal grammar. The majority of the world’s spoken languages use that rule and Chomskyan theory sees it as being the purest expression of innate grammar.

But as the ABSL study has progressed, that early result has not played out as expected.

Despite passing through four generations, > 8 October 2016 | NewScientist | 37

Multiple signs Another intriguing feature of ABSL is its sprawling vocabulary. As is often the case in emerging languages, signers invent new signs by combining existing ones. “Pray” and “house” combine to mean “mosque”; “cold” and “large rectangle” to mean “refrigerator”.

But unexpectedly, these compounds do not appear to be converging onto agreed conventions. Even common nouns can have multiple signs, some used by just one household. For example, there are three different signs for “cat” – whiskers, footprints and the licking of paws.

This phenomenon alerted the researchers’ to a neglected factor in sign language development: social interaction. Urban deaf communities, which tend to be more segregated from hearing society, often encounter strangers and need to make themselves understood. The deaf people of Al-Sayyid, by contrast, all know one another, so are under less pressure to conventionalise.

All in all, research on ABSL is playing into an emerging consensus in linguistics – that Chomskyan theory is a busted flush.

That view is probably best expressed in an influential 2009 article “The myth of language universals”, by Nicholas Evans at the Australian National University and Stephen Levinson at the Max Planck Institute for Psycholinguistics. In it they wrote: “The claims of Universal Grammar… are either empirically false, unfalsifiable, or misleading in that they refer to tendencies rather than 38 | NewScientist | 8 October 2016

Dave Sinai

ABSL’s grammar remains simple, inconsistent and, at best, a work in progress.

When he first began studying ABSL in 2000, Mark Aronoff at Stony Brook University in New York expected it to support Chomskyan theory. But after watching the language evolve unpredictably, with vocabulary developing quickly but grammar more slowly and inconsistently, Aronoff has changed his mind. He now thinks that although we do have an innate capacity for language, it is not uniquely human but rooted in deeper biological properties shared across species.

Another challenge to conventional wisdom is that despite its simple grammar, ABSL can still convey complex ideas. I witnessed villagers fluently describing their dreams and ambitions, gossiping about weddings or births and discussing topics such as national insurance plans and construction projects.

How ABSL achieves this without complex grammar is largely a mystery.

strict universals. Structural differences [between languages] should instead be accepted for what they are, and integrated into a new approach to language and cognition that places diversity at centre stage.”

They argued that only once researchers accepted that diversity, not uniformity, is what makes language remarkable could they begin to truly understand how humans process language, and to what extent its emergence is influenced by a combination of biological and sociocultural forces (Behavioral and Brain

Unspoken word The village of Al-Sayyid in Israel is a natural laboratory for studying the origins of language

WEST BANK

Mediterranean Sea

Jerusalem ISRAEL Dead Sea

GAZA STRIP Be’er Sheva

Al-Sayyid

JORDAN

25 km

Sciences, vol 32, p 429).

That is essentially what has happened with ABSL. When researchers stopped focusing on grammatical structures, they were able to see that while the urge to create the language does appear to be biological, it is also cultural and social, stemming from the villagers’ heritage, identity and social conditions.

But even as ABSL helps to undermine the dominant linguistic theory of the 20th century, it is itself being threatened by forces beyond its control.

Unsurprisingly given their fragile origins and small pool of speakers, village sign languages are at high risk of extinction – usually at the hands of an education system that teaches the official national sign language.

That is increasingly happening in Al-Sayyid.

In 2004, the village was officially recognised by the Israeli government, granting it the right to municipal services. Children were bussed off to deaf schools in other towns where they were exposed to Israeli Sign Language, the country’s dominant sign language with an estimated 10,000 speakers. Then, in 2007, the village launched its own deaf education programme. Teachers were brought in from outside the village, and Israeli Sign Language was the language of instruction.

The effects were soon felt. Where the village once boasted a robust signing community, made up of both hearing and deaf people who learned ABSL early in life, today the hearing and deaf communities are becoming increasingly estranged.

Salah al-Sayyid, a principal at a local school

Left to right: Ishak and his daughters; boys using sign language; Salah and Kawkeb

and the son of one of the village’s first signers, says that the changes have driven a wedge between ABSL-signing parents and their children. Residents under 30, he says, have a greater command of Israeli Sign Language because of exposure in school and on television, and as their social networks expand beyond the village. This trend is expected to grow as more young people find work outside the village, and, with the help of apps like Skype, find it easier to socialise with deaf people from other parts of the country. Kawkeb, one of Salah’s own deaf daughters, married a Bedouin man from elsewhere and talks with him in Israeli Sign Language.

“As we lose ABSL we’re losing everything that comes with it,” he says. “The culture of our ancestors, their values of hospitality, their slow-paced life. We believe that this is

the beginning of the end for the language.”

For now ABSL seems to be uninfluenced

by Israeli Sign Language, but Sandler’s team expects it to undergo a creolisation process, in which the two merge into a hybrid language, or creole. In that case ABSL is likely to be

“ If we lose our sign language, we’re losing everything that comes with it” the junior partner. Israeli Sign Language is perceived as the more prestigious and more practical of the two, and is likely to overwrite ABSL’s vocabulary and grammar.

That would not end linguists’ interest in ABSL. They would shift their attention to the creolisation process, another Like most hearing villagers, Ishak is fluent

useful window on the emergence of structure in language. But the loss of this unique opportunity to study the birth of a language uninfluenced by others will nevertheless be keenly felt.

While there’s still time, researchers are scrambling to collect as much pristine ABSL as they can. In 2014, the team created a dictionary, including a comprehensive history of the language and its many surprising developments over four generations of users. Even once it disappears, the study will go on. The team has recorded enough video footage of the language to keep the Sign Languages Lab at the University of Haifa busy for years.

It is, of course, difficult to decry social transformations that bring deaf children greater access to education and job prospects.

And while some villagers are frustrated by the changes, others have praised the shift towards integration into Israeli society. Even those who regret the inevitable consignment of ABSL to the ranks of historical languages can see the positive side.

“Language is a tool for communication, so it needs to be constantly undergoing revival and renewal,” says Salah al-Sayyid, unsentimentally, as he sips coffee in his front yard. “Just as you may like to look at a picture of your grandfather’s car, you wouldn’t want to drive that car because it wouldn’t hold up to the standards of today. We can’t preserve everything.” n Shira Rubin is a freelance journalist based in Tel Aviv, Israel 8 October 2016 | NewScientist | 39

RMN-Grand Palais / Gérard Blot

The Comte de Buffon’s lively writing transformed our ideas of Earth’s fauna and fired the public imagination. But his insights on climate were impressively wide of the mark, find Mat Zalasiewicz and Jan Zalasiewicz

Joseph Wright of Derby/Getty

PEOPLE

Earth will freeze if we don’t step in H

OW long did it take for the once-molten Earth to cool to its modern temperature?

The question nagged at Georges-Louis Leclerc, the Comte de Buffon. To work it out, he heated iron balls of different sizes and measured how long it took them to cool enough to touch. It is said he asked only women to help him with this experiment – their hands being more sensitive, naturally, for measuring.

With his timescale calibrated, he scaled up to Earth size. He knew the error margins were large; his private notes show estimates ranging from 75,000 to 3 million years. The year was 1778. Even the lower estimate, which he went on to publish, smashed the Biblical timescale of a mere few thousand years.

This result could have been received poorly by the religious authorities of the day, represented by France’s powerful theological college at the Sorbonne. So in his book, Les Époques de la Nature (The Epochs of Nature), Buffon first did some explaining. He wrote a discourse at the front of the book, arguing that the Biblical timescale was metaphorical rather than literal, and that in any case his “purely hypothetical” ideas could in no way harm the “unchanging axioms” of the sacred word.

There were grumbles in high clerical circles, but the stratagem worked. He was left to get on with his science, as he had for half a century.

Buffon’s was an unlikely scientific career.

His father was a lawyer and tax-collector in the village of Montbard in Burgundy and the 40 | NewScientist | 8 October 2016

young Georges-Louis was destined to become a dignitary in local government. After the death of his uncle, the inheritance was used to buy the lord’s rights to the nearby castle of Buffon. Georges-Louis was sent to study law, but his fascination with the natural world made him determined to study science. His father was aghast – the profession of scientist then barely existed, and certainly carried no social standing. But the young man got his way, and soon after won yet another battle with his father, over the rights to the castle.

Bed be damned Gaining wealth and a title fuelled Buffon’s ambition. The first problem the self-confessed sloth had to deal with was getting up in the morning. He employed a servant to physically drag him out of bed at dawn so he could commence the disciplined 12 to 14-hour working days that he would maintain for the rest of his life. The solid graft paid off. He first made his reputation with mathematics, held a position at the French Academy of Sciences and was put in charge of Louis XV’s botanic gardens and later the royal collections of scientific objects.

But Buffon’s prodigious working hours were largely aimed at developing his view of the world: of minerals, plants and animals, including humans. Published over his lifetime in 36 volumes, his Histoire Naturelle put him

on a par with Voltaire and Jean-Jacques Rousseau as a leading thinker of his day; one that often ruffled feathers, even overseas.

He once conjectured that the mammals of the Americas were enfeebled latecomers, developing in cooler, less life-friendly times.

This idea stung a young Thomas Jefferson – a gifted natural historian who later became US president. Jefferson gathered evidence of the splendour of native American mammals and went so far as to send Buffon a crate containing the skin and bones of a large moose as demonstration. They arrived decayed and smelly, probably defeating the point.

After dealing so comprehensively with the natural world, Buffon widened his sights. He decided to reconstruct all of Earth’s history, from its fiery beginnings to an anticipated freezing oblivion, in a single volume – Les Époques. It was arguably the first sciencebased history of Earth, and Buffon’s lively prose generated the kind of atmosphere that Jules Verne would later evoke. He designed “burning mirrors” that could melt rock, and dug deep shafts in search of fossils. His writing style made this groundbreaking research accessible to the public, something many of his peers disapproved of, or perhaps envied.

A fellow savant, Jean-Étienne Guettard, wrote to him: “Yet more Buffonades… A fine adventure story… to be devoured by the maidservant and amuse the lackey.”

Hugely ambitious, Les Époques tried to tell

BnF, Dist. RMN-Grand Palais / image BnF

Vesuvius offered Buffon a window into Earth’s fiery past, but he thought the future would suit animals built for cold climes

MNHN, RMN-Grand Palais /bibliothèque centrale

Earth’s story as an interconnected whole, despite the inevitable chasms in the scientific knowledge of the day. For example, he attempted to explain the sun’s light and heat via forces exerted by the bodies orbiting around it. Absurd? Well, we now know that gravitational forces drive the volcanism on Jupiter’s moon, Io, so at a time when nuclear fusion could not yet be dreamed of, Buffon’s answer was at least thoughtfully wrong.

But it’s what he got right that amazes.

His Earth narrative includes some prescient deductions: that the fossils found deep in rock strata represent organisms now extinct, for instance. Buffon said it would be useful to study these systematically and compare them with living organisms, foreseeing the discipline of palaeontology. Some of his

insights into ancient environments were stunning, as when he wrote that coal was formed in ancient conditions akin to those of the tropical swamps of Guyana – an interpretation still valid today.

He saw that there was a more shallowly buried – and hence more recent – history too. At the time, bones from elephants, rhinoceroses and hippopotamuses were showing up a little below the ground’s surface in Siberia, for example. This fit his model of an Earth whose overall temperature was heading towards a final deep freeze. The far north, he reasoned, must have once been as hot as Africa is today – an early stab at palaeoclimatology.

The seventh and last epoch described in Les Époques was that of humankind. It had a telling subtitle: “When the power of man assisted To avoid conflict, Buffon harmonised scientific and religious views, as in this image from Histoire Naturelle

that of Nature”. Buffon thought global climate was still cooling. After all, Alpine glaciers had been known to overwhelm villages, suggesting an encroaching freeze.

But he thought human action could delay Earth’s frigid doom – by burning wood and coal, among other measures. It was an optimistic first take on the Anthropocene concept, though ironic in the light of today’s climate woes.

Buffon ended Les Époques by looking forward to humanity progressing through the peaceful use of science. The book was admired by some – it is said Catherine the Great of Russia was captivated by it – but disparaged by others for its “Buffonades”. Such criticism did not unduly trouble Buffon: his position on style was always clear. “Only those works which are well-written will pass to posterity,” he wrote. “The amount of knowledge, the uniqueness of the facts, even the novelty of the discoveries are no guarantees of immortality... These things are exterior to a man but style is the man himself.”

“ A fine adventure story, to be devoured by the maidservant and amuse the lackey” Despite his confidence, the perception of Buffon as a phrasemonger did not help his later reputation, nor did his dismissal of Carl Linnaeus’s newfangled but ultimately enduring scientific naming system. He died of natural causes in 1788, aged 80. It was the year before the French Revolution, which swept away the Ancien Régime, of which Buffon had been a part. His timely death spared him a date with the guillotine (his son was not so lucky).

The new wave of scientists had their own careers to burnish, and their stars came to eclipse Buffon’s. Yet his breathtaking ambition in reconstructing an evidence-based, holistic account of Earth and its inhabitants should not be forgotten. Buffon brought real science to the people with his vivid writing. And that’s something to be celebrated in any era. n Father and son Jan and Mat Zalasiewicz are involved in the first complete English translation of Les Époques de la Nature, to be published next year 8 October 2016 | NewScientist | 41

culture

E-paradise lost?

Could the internet have been other than it is, wonders Sally Adee

DOES anyone remember what the internet was supposed to be?

I have hazy memories of a limitless prospect, complete with author William Gibson’s consensual hallucinations. Before we knew how connecting the world would play out, there was a low-res, mythical quality to our cyberspace future.

Two decades on, and Nicholas Carr’s Utopia is Creepy reveals the reality into which these promises have crystallised. Curated from his blog posts over the past 10 years, the book is full of wry vignettes and articles lampooning the motivated enthusiasm and game-changing promises of Silicon Valley’s tech bro elite.

Carr’s targets of “disruption” range from music and cars to breakfast and bras. And what have we reaped after 20 years of this disruption? Well, it’s not utopia.

Then again, Carr has never been much of an enthusiast.

He’s probably best known for The Shallows, a 2011 Pulitzer finalist, in which he discussed how access to an infinitely broad but infinitely shallow information landscape has changed our brains. Not for the better, he fears. As Microsoft’s smart bra suggests, instead of utopia, our petty oppressions have just been projected into a new dimension. The bra monitors emotions and heart rate. Why? Buy! Buy! Buy! Twenty years on, the internet is a loud marketplace 42 | NewScientist | 8 October 2016

To detect stress and stop Facebook, Twitter or Instagram to emotional eating, of course. ensure our self-representation is It’s all a far cry from Donna polished and generating clicks.

Haraway’s “A Cyborg Manifesto”, Carr broadens the context: an essay celebrating technology’s disguising unpaid labour as potential to free us from the “fun! content! web 2.0!” lets constraints of gender roles. Carr’s Silicon Valley shift its overheads book isn’t a polemic, but a mosaic to “customers” and clutter up with individual tiles, by turns their lives. It also allows the cute, funny or chilling. And it’s amateur to be monetised, as the more than the sum of its parts, efforts of volunteers are turned as two big themes emerge. into “the raw material for profitThe first concerns the steady making companies”. drumbeat of criticism for web A quieter theme is the fear of 2.0 and user-generated #content. “ Disguising unpaid labour The book’s 10-year span shows as ‘fun! content! web 2.0!’ the transition from promise to lets Silicon Valley shift its millstone. Content has become overheads to ‘customers’ ” like a second job – we update

Laurence Dutton/Getty

Utopia is Creepy and Other Provocations by Nicholas Carr, W. W. Norton, $26.95

freedom. A memorable takedown

by Carr features Facebook’s first TV ad in 2012. Called “The Things That Connect Us”, it’s a montage of cosy objects and welling music, ending with a childlike voice-over: “The universe. It is vast and dark.

And it makes us wonder if we are alone. So maybe the reason we make all of these things is to remind us that we are not.”

Perhaps this explains our drive to taxonomise things to death because we fear just experiencing them. In a telling example, Carr pokes fun at a famous critic’s notion that the internet improved poetry by “disrupting” its elitist allusions. The critic cites T. S. Eliot, who had to append notes to The Waste Land to allow readers to keep up with its many allusions.

Today, he writes, “no poet could outwit a reader who has an internet connection”.

You can hear Carr’s heavy sigh. The more you Google the poem, he says, the less you hear it: “Much of what’s most subtle and valuable in culture... is too blurry to be read by machines.”

This is an uncompromising portrait of the internet as a vulgar, cramped, unpleasant marketplace run by marketers, surveillance states and people shouting at you. But Carr acknowledges its upside: in 2014, the Pew Research Center showed 90 per cent of US citizens thought the internet was a force for good. Another statistic had the internet population spending $83,000 on Amazon per minute. Utopia perhaps, but an extraordinarily narrow vision of it.

Swallow the book in a few gulps and you sense we had the chance to create something new but that we let marketers and advertisers move in. Paradise lost indeed. n

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

Editorial omissions Where’s the moral vision behind gene editing, wonders Matthew Cobb

by John Parrington, Oxford University Press, £22.99

At last December’s international summit meeting in Washington DC on the ethics of using CRISPR on humans, it was agreed to maintain a moratorium on germline manipulations that would be transmitted to future generations.

The reader deserves a description of this decision, and a brief exploration of why it is a line that should not be crossed.

Ethical considerations seem to be added as an afterthought, rather than being interwoven with the excited descriptions of the latest technical developments.

This is particularly clear in the coverage of “gene drives”.

Scientists have developed a

THERE is a revolution going on in the life sciences, one that has already transformed scientific discovery and will soon change medicine. It could even see us altering the ecosystem in a precise, targeted way. This revolution has a name – CRISPR – and the key part of John Parrington’s Redesigning Life is a good summary of the gene“Procedures that would editing technique that lies have seemed impossible behind the acronym. only five years ago are Like any major technological now widely available” change, CRISPR raises profound ethical questions. Through technique to get a mutant gene its ease of use and technical to copy itself onto both copies simplicity, this tool enables us of a given chromosome in an to manipulate genes in almost animal or plant. This procedure any organism. Procedures that has been made much simpler by would have seemed impossible the application of CRISPR. Gene only five years ago are now drives enable a gene to spread widely available. rapidly through a population; Parrington intends his book to be a “useful starting point” for our there are plans to use them to combat mosquito-borne diseases ethical discussions about these by making the flies sterile or possibilities. But to come to a unsuitable as hosts for various conclusion about whether we viruses and parasites. should be “redesigning life”, we On the surface, this may not only need to understand the science; we also need to be shown seem like an excellent idea.

The trouble is, a gene drive is the potential consequences of its effectively a biological bomb application, for both good and ill. that, once released, will When dealing with this vital explode with potentially question, the book stumbles. unknown consequences.

We are told, for instance, Parrington briefly states that that human cloning raises there are ecological concerns, major ethical issues, but are but does not address the obvious given not one hint of what these question of who should decide are, who might raise them, or whether a particular gene how legitimate they might be.

Mark Joste/Millenium Images,UK

Redesigning Life: How genome editing will transform the world

drive should be released.

Communities affected by Zika virus or malaria should obviously have a say, but the ease with which vectors are transported around the world – a factor that led to Zika’s recent arrival in the Americas – shows that what is decided in one place could have an effect in another.

Many scientists involved in this research are extremely worried about the dangers. Some have suggested that we should prepare a “reset button” in case it all goes wrong – a second gene drive, returning the genome of the altered species to its original form. Although this might help to halt inadvertent change, it would not do anything to restore the

New model army: what will editing the genome do to human variety?

ecosystem to its original state.

The issue of regulation is at the heart of the new genetic technology, and an international regulatory authority, like those that control potentially lethal activities such as atomic energy or civil aviation, could be set up.

Even a brief mention of such a possibility, and the reasons why it might or might not be created, would have made Redesigning Life much more useful. n Matthew Cobb is a zoologist at the University of Manchester, UK. His latest book is Life’s Greatest Secret: The race to crack the genetic code 8 October 2016 | NewScientist | 43

culture

Furry friend or mass killer?

Let’s see our cats as they really are, finds Adrian Barnett

THE idea of curfews on domestic cats in a bid to protect native species is a hot topic in Australia.

But it’s just the latest salvo in a long-standing battle over how to live with the domestic cat in the modern world. Doubtless the truth about cats’ toll on wildlife will turn out to be more nuanced as the science emerges, but meanwhile there are sides.

On the one side, there’s Moggie the Mass Murderer, which sees cats as directly responsible for the extinction of many species of mammal, bird and reptile (63, according to a recent PNAS paper).

Then there is Kitty the Dilettante Eviscerator. This side argues that domestic cats are not efficient killers, and that since the animals preyed on are often underweight or sick and would die soon anyway, cats are sweeping up Darwinian surpluses that would otherwise have us kneedeep in goldcrests in a decade.

These arguments underpin two very different books, Cat Wars

by Peter Marra, director of the Smithsonian Migratory Bird Center, and writer Chris Santella; and The Trainable Cat by biologist John Bradshaw and animal psychologist Sarah Ellis.

Bradshaw has had success with his previous books Dog Sense and Cat Sense. This time he has teamed up with Ellis to explain Ostensibly friendly felines are killing billions of other animals 44 | NewScientist | 8 October 2016

why cats do what they do and how healthy lives than cats walked to (gently) modify their behaviour on leashes or kept indoors. The to make life better for everyone. change just requires training and Training an animal that is a human willingness to play with byword for independence may them. This may also be a wise seem like an oxymoron. But, after move if cat sanctions catch on pointing out that cats are social globally, since it would make and learn interactively, Bradshaw indoor life more interesting. and Ellis provide insights into Cat Wars has a broader, more how to ensure training plays to ecological focus, documenting the the all-important cat principle: global impact of cats on wildlife, pleasure. Based on the power of “ Cats that range freely cat-owner affection and food outdoors live shorter, more treats, their training should curb violent lives than cats on killing instincts and make cats leashes or kept indoors” less stressed in the un-catlike environment we foist on them.

Preying on wildlife aside, the both by preying on animals and writers point out that cats allowed by transmitting diseases. As we all to range freely outdoors live know from the dead “presents” shorter, more violent and less our cats bring us, most cats hunt.

Duygu Yilmaz/EyeEm/Getty

The Trainable Cat: How to make life happier for you and your cat by John Bradshaw and Sarah Ellis, Allen Lane, £20; Cat Wars: The devastating consequences of a cuddly killer by Peter P. Marra and Chris Santella, Princeton University Press, $24.95

But, argue the writers, all those little saucers of food that cats also devour push their densities way above what’s natural for carnivores of their size. Hence the collective impact of even occasional preying is huge, with domestic cats killing some 14 billion small birds and mammals a year in the US alone.

Worse, many bird species are migratory, so one death-by-cat in Venice, California, also means one less bird in the Costa Rican bush.

The problem has a deep history.

Starting with the Stephens Island wren, wiped out in less than a year

by Tibbles, a lighthouse keeper’s cat, Marra and Santella detail a series of cat-caused massacres. In response to Bradshaw and Ellis’s view that cats only take up the ecological slack, they argue that in a time of climate change, cats provide an extra (and avoidable) source of mortality.

Then there are cat-borne diseases. The most worrying, toxoplasmosis, has caused declines in sea otters, beluga whales and the critically endangered Hawaiian monk seal, among others. It also causes birth defects in humans.

Marra and Santella explore the solutions (keeping cats indoors, catios – an enclosed area outside the home – and killing strays), and show how the culling option has met with huge resistance from “animal lovers” despite the harm to wildlife cats cause. While the US-centric focus and birding history diversions may tire some readers, this is an important and eye-opening book that clearly says: “keep Tiddles a house cat’’. n Adrian Barnett is a rainforest ecologist at Brazil’s National Institute of Amazonian Research, Manaus

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LETTERS editor’s pick

More perverse biofuel incentives From Peter Eastwood Michael Le Page doesn’t describe all the problems with biomass energy in the UK (24 September, p 20). The government’s Renewable Heat Incentive pays businesses to get their heat from renewable sources. We have a half-megawatt, woodchip-burning boiler, which cost about £250,000.

We received no capital grant towards the boiler, but are paid 5.2 pence per kilowatt-hour of heat we use – slightly more than the cost of the woodchip fuel. Businesses that joined the scheme earlier get paid up to twice as much. The payment is index-linked and guaranteed for 20 years.

In the past we were constrained in how much fuel we used by the cost of the oil. Now that is no longer the case, there is no incentive to burn less fuel. The scheme is not helping to reduce carbon emissions in the UK. The best way to cut them must be to cut energy use, not to get paid more to use more energy.

Ditchling, East Sussex, UK From Perry Bebbington To get an overall view of the effect of reducing CO2 emissions, just take a look at the “Keeling curve” of concentrations in the atmosphere measured at Mauna Loa in Hawaii.

If you look carefully you should be able to see where the curve starts to turn down as we reduce our emissions. Can’t see where that happens? No, neither can I. Kimberley, Nottinghamshire, UK 52 | NewScientist | 8 October 2016

letters@newscientist.com

Reasons not to play Russian roulette From Carl Zetie You mention the “Quantum Russian roulette” test for the many-worlds interpretation of quantum theory, in which the spin of a photon determines whether an experimenter gets a bullet or a blank fired at them (3 September, p 36). If still alive after 50 rounds, they can assume they live in a multiverse.

But this repeats an error that occurs in much “reasoning” about multiverses. It may seem that the outcome is the result of many trials. In fact, this is an attempt to reason probabilistically about a sample size of just one – because we observe the results only in one universe. In fairness, the nature of randomness is deeply confusing.

The flaw is clearer if we strip away the dramatic set-dressing of the researcher and the gun, and consider only the photons. Of the approximately 1015 possible sequences of 50 shots, exactly one must occur, though any given sequence is highly improbable.

One-in-a-billion chances happen all the time, because one of them has to.

And the experiment fails to clear the hurdle of falsifiability. If the colleagues of an experimenter who gets a bullet aren’t justified in concluding that there is no multiverse – and I doubt anybody would argue that they are – then the experiment proves nothing.

Waterford, Connecticut, US

Cold fusion creates cold comfort From Ron Dippold The major takeaway I had from this report was how similar “cold fusion” is to New Age quackery.

You discuss sincere people who believe that with just a little more work and funding we can make some real breakthroughs; but

there are also people who at least behave like classic hucksters.

Regular readers of your Feedback column may find it all very familiar. I firmly support other people’s money being spent on this, and may you become fabulously wealthy, but I won’t be holding my breath.

San Diego, California, US From Herman D’Hondt I read with interest that the US Naval Research Lab and the US House Committee on Armed Services are interested in cold fusion. The US armed forces have form on interesting notions. I’ll skip lightly over Ronald Reagan’s Star Wars, and instead mention Project Stargate. This was the US Army’s 1980s psychic warfare project under the command of Major General Albert Stubblebine.

It was immortalised in the film The Men Who Stare at Goats starring George Clooney, based on a book by Jon Ronson.

Newtown, New South Wales, Australia

Other paths for blood bacteria From Stephanie Woodcock Debora MacKenzie reports two routes of entry for bacteria into the bloodstream: the gut and the gums (17 September, p 8). Longterm covert bacterial infection can enter the body in other ways, for example, through the genital tract, through injured skin or via insect bites.

Most bacterial conditions are treatable, but in many it is impossible to guarantee a complete cure. Someone unfortunate enough to acquire systemic MRSA infection may always carry a low level of it.

Both syphilis and the Borrelia bacteria that cause Lyme disease are known to be capable of making a reappearance even after treatment was deemed adequate.

Many different types of bacteria

@newscientist

newscientist

can hide in the body, with the potential for low levels to leak into the bloodstream. It may be necessary to cast the net more widely than just gut bacteria to fully study the effect of these possibly not-so-dormant bacteria.

Penryn, Cornwall, UK

In medicine only aphorisms survive From Andrew Sanderson Your article on reversals in medical practice struck a chord (27 August, p 34). In the late 1960s I was taught by Henry Miller, then professor of neurology at Newcastle University. His aphorism, confirmed throughout my medical career, was: medical facts (things we know to be true) have a half-life of five years Spennymoor, County Durham, UK From Peter Haydon Dumping ineffective medical treatments is nothing new. Hence the expression, “Yesterday’s heresy is today’s orthodoxy, is tomorrow’s fallacy.”

London, UK

Why gods keep on coming back at us From Malcolm Shute Maybe one of the reasons that the concept of God, or gods, keeps entering into your scientific discussions (3 September, p 28) is because she/he/it/they really do exist, by our own definition.

When we first learn maths at school we are taught that “5 takeaway 7” “can’t be done”. Later, the minus sign is introduced as a sort of error message. Putting a magnitude on the error opened the way for us to do mathematics with negative numbers. Later we are taught that 5 divided by 0 is erroneous; but introducing an infinity sign led to the notions of countable and uncountable

“ I used to have bat fish in a saltwater tank… I never thought to listen!” icky is intrigued by our report of bat fish recorded V singing dawn choruses with others (1 October, p 16)

infinities and more, and some ability to manipulate those quantities.

Maybe the concept of God or gods is just our natural way of symbolising all that is beyond our reasoning, and thus a tag with which we can then start to reason about it all.

La Tour d’Aigues, France From Donald Windsor Like Schrödinger’s famous cat, God simultaneously exists and does not exist until the observer (each of us) opens the box. The elegant beauty of metaphysics is that it presents us with this divine box and then challenges us to figure out a way to open it.

Norwich, New York, US From Phil Stracchino Graham Lawton states: “The only coherent and rational position is agnosticism.” He has neglected ignosticism, defined formally as the theological position that all other theological positions – including agnosticism – make too many unquestioned assumptions about the nature of godhood.

You cannot have a fully rational Tom Gauld

discussion about any subject without first establishing an agreement as to what the terms you’re using actually mean. And when you ask that question, you rapidly learn that most people can’t actually answer.

Gilford, New Hampshire, US

From Heikki Ketola The New York Times reported in 2011 on the Tsunami Stones, some 600 years old, in the Sendai area of Japan. They warn people not to build anything below them lest it be destroyed by a tsunami.

Malibu, California, US

Grave messages for What about them future readers Minoans, then?

From Richard Horton Jonathon Keats, reviewing Time Travel: A history, states that “only since the 20th century have we sought ways to communicate with the future” (10 September, p 42). Those of us who survey churchyards and record memorial inscriptions know that this desire goes back much further. Here, for example, is part of an inscription in St John’s Kirkheaton, West Yorkshire, clearly addressed to future readers: “… Also of Sarah daughter of the above named Mark and Ann Fisher… What we are now so you must be, therefore prepare to follow me.”

Whixley, North Yorkshire, UK

From Mick Morris Was the Indus civilisation as unique as Andrew Robinson suggests (17 September, p 30)?

Parts of his article could have been describing the Minoan society of prehistoric Crete, extant at about the same time.

There is little evidence of warfare in Minoan society; no memorials of battles or powerful leaders; nor are there examples of weaponry beyond the symbolic.

The Minoans traded exquisite carved seal or gem stones around the eastern Mediterranean.

Their housing showed little in the way of hierarchy, with most living in 5-roomed dwellings.

They appear to have kept stores of food, olive oil and wine that we think were used to feed the population in leaner periods.

Women were as frequently portrayed as men in the images we have discovered, and appear to be taking at least an equal part in the ceremonies shown.

Waterlooville, Hampshire, UK

Cocky pundits trumping reason From Jörg Michael James Hoggan says of the rhetoric of US presidential candidate Donald Trump that “People are mainlining… a cocktail of absolute certainty, strong opinion and talk of control… People turn to such versions of reality because it’s mentally more comfortable than dealing with uncertainty and anxiety” (16 July, p 18). We have been here before.

In the aftermath of the 2008 banking crisis you reported research showing that people prefer advice from a confident source, even forgiving a poor track record (6 June 2009, p 15).

Hanover, Germany

For the record n It was John van Aardenne from the European Environment Agency who observed that “In theory, if a forest is felled for biofuel, it should be reported in the EU’s greenhouse gas inventory” (24 September, p 20). n Elephants can make 200-litre puddles, but only with multiple footprints (3 September, p 12).

Letters should be sent to: Letters to the Editor, New Scientist, 110 High Holborn, London WC1V 6EU Email: letters@newscientist.com 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.

8 October 2016 | NewScientist | 53

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FEEDBACK

IN THIS post-truth era, Feedback is delighted to discover one company using trickery for the powers of good.

New Scientist has often mused on the mystery of how bicycles stay upright (5 September 2015, p 32). Dutch cycle makers VanMoof found themselves wondering the same, after customers received bikes that had been damaged by boisterous handling during the delivery process. Then they devised a novel solution.

Realising that its boxes were about the same size as a very large television, the company started printing a picture of one of those on the side of each box instead of a bicycle – a move it claims has since cut shipping damage by 70 per cent.

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Bohannon’s actions received far greater coverage as the story started to focus on whether performing a fictitious study to draw attention to lax journalistic practices was any more ethical than doing so to sell chocolate.

German authorities have now decided it is not – and sanctioned Gunter Frank, the doctor who took blood samples from people in the study, none of whom were aware they were participating in a bogus trial. Frank was fined €500 for failure to obtain full consent or arrange an ethics committee.

A final bitter aftertaste in the chocolate chicanery?

Paul McDevitt

MORE fakery: to dodgy studies and

LAST year, journalist John Bohannon announced he had “fooled millions” with a bogus study on 16 people that claimed to show eating chocolate could help you lose weight. The study was press released into the world, and picked up by such august journals as Bild, the Daily Star and “both the German and Indian site of The Huffington Post”.

bogus journals, we can now add a tool for generating fake peer reviews.

Noting that “commercial publishers may find… excellent opportunities for profit, even in the form of journals with little or no scrutiny”, Alberto Bartoli and his colleagues have thrown a lit match into the tinderbox of predatory publishing with a software program that can produce plausible-looking reviews on demand.

Jeff Dickens is intrigued by an email from travel company Booking.com that included the sage advice: “Plan ahead for the best trip yet. Minimise stress by completing your trip before you set off.”

56 | NewScientist | 8 October 2016

In 25 per cent of cases, the machine-generated reviews were good enough to fool experienced readers into agreeing with them while rejecting a genuine review.

the environmental group. Has anyone calculated the carbon footprint of this war of words over fracking?

Feedback is left wondering if we can believe anything we read – even papers on how to publish fake scientific papers.

IMPORTANT news for those in a bind: the Journal of Acute Medicine has published a case report of man who arrived at the emergency department of Kuang Tien General Hospital in Taiwan with his badly swollen scrotum “incarcerated” in nine galvanised iron rings.

Unsuccessful attempts were made to remove the rings with lubricants, ring cutters, pliers and orthopaedic bone cutters, until finally the doctors

MEANWHILE, presidential candidate Donald Trump’s weak grasp of reality appears to be catching. During the recent televised debate, the Republican nominee denied ever claiming that global warming was a hoax.

Feedback readers will recall Trump has done just that on Twitter, on several occasions (13 August). Rumours circulated that his team had quickly deleted the offending messages, a claim that itself turned out to be untrue.

To paraphrase another Donald, (Rumsfeld this time) “There are true untruths, and there are untrue untruths...”

borrowed a hydraulic bolt cutter from the nearby fire department, and freed the man from his predicament.

The authors note drily that such emergency challenges require “resourcefulness and a multidisciplinary approach”.

FINALLY, a claim we hope is true.

Hannah Hazlehurst discovers that Marmax Products, a company that sells recycled

WHO will rid us of these troublesome untruths? Environmental campaign group Friends of the Earth has been accused of misleading the public about the dangers posed by fracking.

A flyer received by Reverend Michael Roberts last year implied that Grasmere in the Lake District was threatened by shale gas extraction.

The retired geologist noted on his blog that “this scare story is so laughable as the rocks on surface are Ordovician Borrowdale volcanics” – so the rock beneath has no organic material to tap.

The Advertising Standards Authority (ASA) has now agreed, adding that claims about poisoned water supplies and plunging house prices could also not be substantiated.

MEANWHILE, the same body reversed a ruling passed in May on a Greenpeace anti‑fracking flyer, which claimed that “experts agree – it won’t cut our energy bills”. Having originally sided with the complainant, Lord David Lipsey, the ASA rescinded the verdict on the basis of new evidence and found in favour of

plastic furniture to schools, claims it has “saved enough plastic milk containers to do 2 orbits around the space station”.

Feedback certainly doesn’t remember seeing that bit of craftwork on Blue Peter – do Elon Musk or Jeff Bezos know about the impressive propulsion of these bottle rockets?

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THE LAST WORD Seal meal We hear that polar bears are under threat from climate change and may starve as the world’s ice melts. This is because it is difficult for them to venture onto thinning sea ice to find their preferred food – seals. But presumably the seals will still breed somewhere. Where is that, and will it be accessible to polar bears?

are rare and would not provide sufficient food for many bears.

Antony David London, UK

Silencing them for military reconnaissance proved effective.

During the Vietnam war, for example, the Lockheed YO-3 was practically inaudible at an altitude of 300 metres. But muffling the engine, especially the air intake and exhaust, is costly in terms of weight and affects performance: the efficiency of internal combustion engines is sensitive to how easily they can be fed air and how well they “breathe”.

However, silencing engines proves less demanding than silencing propellers, for which

n That the seals will still breed somewhere is more of a presumption than you might think. Polar bears feed mainly on seal species that prefer thick sea ice and, of these, the ringed seal is probably the most important.

This species is also the most specialised for breeding in sea-ice caves, so if these become scarce, it could be a serious problem for them – and therefore for the bears.

The bears are not limited to solely eating seals: they can find other food, ranging from crabs to walrus. But they are reliant on a particular annual feeding pattern.

They depend on finding a glut of fat-rich marine mammals on sea ice during the springtime, then trying to survive the seasonal summer famine by relying opportunistically on less suitable food such as fish or reindeer, or on scavenging and scraps.

Such titbits improve their chances of survival, but are an insufficient diet in themselves.

A bear that locates a seal that is not dependent on ice, or a sea lion rookery on a beach, can no doubt make do, but these finds

n The biggest problem polar bears face with their prey is catching it. A bear would get nowhere chasing a seal in the water, and while the bear is faster on land, seals stay close enough to the water for this to be of little use.

Polar bears have therefore adopted a particular hunting strategy. Seals swim under the ice to catch fish, but must come up for air from time to time. The bears lie motionless beside holes “ In the Vietnam war, the Lockheed YO-3 was in the ice and make a quick grab practically inaudible at an when a seal surfaces. Without ice altitude of 300 metres” strong enough to hold the bears’ weight, seals might be numerous but the bears won’t catch them. blade width, length, shape, Guy Cox rotation rate, choice of material St Albans, New South Wales, (wood, metal or synthetics) and Australia number of blades are all factors to consider. Each of these also affects cost, weight, performance and safety. In the competitive Aerial drone business of small-aircraft Why do light aircraft with piston manufacture, noise abatement engines make so much noise, even and sophistication are when they are far away? They can be understandably lower priorities very intrusive, especially in secluded than cost and proven design. landscapes such as Dartmoor National But as the number of airfields Park. Are they fitted with silencers like and light aircraft in population road vehicles are? And if not, why not? centres increases, the demand for sound abatement is intensifying. n Designers traditionally gave As a result, muffled engines and little thought to noise in small cheap, efficient scimitar-shaped aircraft, concentrating instead on blades, which are quieter than lightness, simplicity, payload and other types, can be expected in performance. Research has shown new standard designs. that the engines and propellers Jon Richfield make most of the noise.

Somerset West, South Africa

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n I can suggest a number of reasons why light aircraft make so much noise. The first is that they are predominantly flown as a hobby, so cost is a major factor.

Therefore light aircraft need to be just that: light. The heavier a small plane is, the bigger the wings and engine need to be, all other things being equal, and the more expensive to run.

Adding silencers incurs undesirable cost, as well as complexity and weight. For that reason, most light aircraft don’t have them.

Silencers also reduce engine power and, because light aircraft tend to be built with the smallest and least powerful engines possible, anything that reduces power is highly unwelcome.

Finally, small planes tend to fly slowly, relatively close to the ground and below the clouds.

This means the noise is louder and more persistent at ground level than it would be if the plane were flying higher and above a muffling cloud layer.

Manek Dubash Lewes, East Sussex, UK

This week’s question On the farm

It always seems that, in any wind farm, at least one of the cluster of turbines isn’t turning. What is the reason for this? Is it undergoing repair or are there other, more interesting, factors at work?

Pierre Aurigny Toulouse, France

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