October 22 - 28, 2016 New Scientist

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CARBON CONUNDRUM Solving the universe’s existential mystery

DAM RIGHT How beavers can sort out California’s drought

BRIE ENCOUNTERS Cheese is a hotbed of bacterial evolution WEEKLY October 22 - 28, 2016

KIDS UNLIMITED Stem ceell success coulld end infertilityy

IS YOUR Somebody, somewhere is putting a price on your h head

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CONTENTS

Volume 232 No 3096

This issue online newscientist.com/issue/3096

Leaders

News 5

8 Human eggs made in the lab from skin could be just five years away

News PASCAL GOETGHELUCK/SCIENCE PHOTO LIBRARY

The end of infertility?

It’s distasteful, but we need a price on our heads. Fertility progress is good for all of us

6

UPFRONT Mars lander arrives. Hospital infections boom across Europe. Whale faeces to stop whaling 8 THIS WEEK New lakes swamp sinking islands. Strange stars as a SETI signal? Microbial parties in cheese. What you’d look like with Botox. Proxima Centauri acts like the sun. Overweight mothers have older babies 15 IN BRIEF Worms farm plants. Uranus’s new moons. Electrodes let quadraplegic man feel touch

On the cover

28

34 Carbon conundrum Universal mystery 36 Dam right How beavers can sort out California’s drought 10 Brie encounters Cheese and evolution 8 Kids unlimited Stem cell success 24 Blood from a drone Rwanda’s flying transfusions

How much is your life worth? Somebody, somewhere, is putting a price on your head

Analysis 18 Animal culling Is it ethical to sanction mass killing of animals – and does it even work? 20 COMMENT A glimmer of sanity in the war on drugs. Samsung’s meltdown may not be the last 21 INSIGHT Let women take control of their abortions

Technology 22 Mountain sensors monitor California’s water. Lasers stop drones crashing. First UK trial of driverless cars. UAVs deliver blood

Aperture Features

26 Orangutan scales dizzying heights

36

Features 28 How much is your life worth? (see above left) 34 Carbon conundrum Solving the universe’s existential mystery 36 Dam right (see left) 40 PEOPLE Chuck Hull and the invention of 3D printing

How beavers can sort out California’s drought

MICHEL ROGGO/NATUREPL.COM

Dam right

Culture

Coming next week… Our implausible universe The more we look at it, the less sense it makes

Into uncanny valley Why do some faces unsettle us?

42 Picking up the pieces The 9/11 forensic investigation is casting a long shadow 43 Live long What older men are really for 44 Art, but no artist Philippe Parreno ceded control of a huge installation to microbes

Regulars 52 LETTERS Compare a mystery and a fake 56 FEEDBACK Pet radio 57 THE LAST WORD Fly away home?

22 October 2016 | NewScientist | 3

Professor Dame Carol Robinson 2015 Laureate for United Kingdom

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Put a price on your head Valuing human life in financial terms can be the fairest option A CYNIC, said Oscar Wilde, is somebody who “knows the price of everything but the value of nothing”. If so, then some of the most cynical people on Earth are those who have to make life-anddeath decisions about road safety, medical treatment and health and safety legislation. In order to make those calls, they first need some measure of the monetary worth of a human life. That does seem a dreadfully cynical calculation, and it is unsettling to think that some faceless bureaucrat somewhere is putting a price on your head (see page 28). But in reality, it cannot be any other way. If we were to embrace the idea that life has immeasurable value, then there

would be no ceiling on how much we would be prepared to spend to reduce the chance of dying, even by an infinitesimal amount. That may seem morally right, but it is economic madness. Take the US healthcare system, where the cost of treatment is often not considered. That has contributed to rampant inflation; the US now spends a fifth of its GDP on healthcare. Contrast that with the UK, where healthcare is a public good that must be distributed fairly with cost considered. This makes a difference: basic health outcomes, such as the number of preventable deaths, are far better in the UK. The people who make those calls on behalf of the NHS often

A time like the present THE Italian government recently got into trouble over a campaign aimed at reversing the country’s falling birth rate. Adverts saying “Beauty has no age limit. Fertility has” were slammed for being insensitive to young people struggling financially, and insulting to infertile couples. Tin ear or not, the campaign highlighted some serious points. Fertility is falling; the population

is declining and ageing. That may sound good to those who see overpopulation as the root of all ills, but a crash is not a desirable way to solve the problem. And the volume of misery that infertility causes is underappreciated. It often comes about because people are trying for children later in life, relying on medicine to help. That is one reason to celebrate the latest advances in fertility

find themselves facing bad publicity. The UK’s National Institute for Health and Care Excellence (NICE) is frequently criticised for, say, refusing to pay for an expensive new cancer drug. In reality, NICE’s methods are fair and equitable. The world should embrace its formulas, not criticise them. In realms outside of healthcare, the value of a life is all over the map, often decided on a whim or according to highly subjective criteria. We should set aside our squeamishness about putting a price on a life – and also any romantic notion that to even ask that question is morally repugnant – and start to do so openly and fairly. Cynicism is sometimes the fairest way. ■

treatment. Last month, we broke the story of the first three-parent baby born using a technique that saved him from a fatal disease. The same method is helping infertile women conceive. Now, scientists have worked out a way to create fertile mouse eggs from adult skin cells (see page 8). The feat will almost certainly be replicated in humans. For those who want children, there might not be a perfect time to start a family, but advances like this will help people choose their time. ■ 22 October 2016 | NewScientist | 5

REINHARD DIRSCHER/WATERFRAME/GETTY

UPFRONT

Salvation by dung? MURKY whale waste may have a silver lining: it could be the unlikely catalyst for ending whaling. The way whale faeces helps maintain fish stocks will take centre stage this week and next at the International Whaling Commission meeting in Portoroz, Slovenia. For the first time in the IWC’s 70-year history, delegates will be invited to vote on a resolution

phytoplankton. These tiny organisms are eaten by krill, which become prey for fish. Phytoplankton also suck carbon dioxide out of the air, helping to limit global warming. Chile submitted the unprecedented resolution for member states to vote on. “This is an exciting new horizon for the IWC,” says Claire Bass of animal advocacy group Humane Society International. “It inspires

acknowledging growing evidence that whales don’t decrease fish populations – the primary excuse for continued whaling by Japan, Norway and Iceland. Whales actually have the opposite effect. Research is revealing that their dung brings nutrients to surface waters, which generates more food for fish by stimulating the growth of

us to see whales not as resources to be exploited, or as competitors for fish stocks, but as ecologically essential geoengineers.” “It means there will be an increased focus on whale conservation activities rather than concentrating on whaling all the time,” says Sharon Livermore of the International Fund for Animal Welfare.

–It’s good for the ecosystem–

UK’s dirty air case THE UK government is being hauled back into court over its failure to tackle air pollution. A group called ClientEarth is asking the High Court to order ministers to come up with a better plan for improving air quality. The case concerns levels of nitrogen dioxide, an invisible gas that mainly comes from road traffic. High levels shorten lives by raising the risk of heart attacks, strokes and respiratory disorders. A 1999 European Union directive setting legal limits for

“Court cases have helped raise public awareness of air pollution and put it on the political agenda” nitrogen dioxide levels came into force in 2010. Six years later, these limits are still being exceeded in many places across Europe, partly because a high proportion of cars run on diesel. In the UK, 37 of the 43 zones the country is divided into breach the limits. ClientEarth, a group of lawyers who use existing laws to 6 | NewScientist | 22 October 2016

protect the environment, first took the UK government to court in 2011. The case was referred to the European Court of Justice, which ruled in 2014 that national courts can and should ensure that governments act to bring air pollution below legal limits. It also ruled that governments must do this “as soon as possible”. The case then went back to the UK’s Supreme Court, which in April 2015 ordered the nation’s environment minister to take “immediate action” by preparing and consulting with the public on an air quality action plan as quickly as possible. But little has happened since then, prompting the new case. And ClientEarth is not just suing the UK government. Based on the precedent set by the European Court ruling, it has launched or helped to launch similar actions in Belgium, Poland, Germany and the Czech Republic. While these legal battles have yet to bring much concrete action, the court cases have helped raise public awareness of air pollution and put the issue on the political agenda.

Spies in the dock BRITISH spy agencies collected data illegally for more than a decade, a court has ruled. The Investigatory Powers Tribunal, which looks into complaints against GCHQ, MI5 and MI6, said on 17 October that the agencies’ secretive collection and use of bulk data from people in the UK failed to comply with human rights laws until 2015. Bulk communications data has been collected since 1998, and includes information such as the

time and location of a communication, but not the content of the message. Bulk personal data, gathered since around 2006, includes biographical details. “This information reveals a lot about you,” says Camilla Graham Wood from campaign group Privacy International, which put forward the complaints. Although the data collection was ruled to be illegal before 2015, when it was made public, the tribunal found that the agencies’ data collection is now lawful.

China’s testing month in space CHINA has sent a pair of astronauts to live on its experimental new space station for a month. Jing Haipeng, who is on his third mission, and Chen Dong were due to dock with the Tiangong-2 space station on Tuesday evening (GMT). During their 30 days on board, they will carry out 14 experiments. These include a plant cultivation study, a quantum communications experiment and using a gamma-ray burst instrument called POLAR,

which is a collaboration between Chinese, Swiss and Polish scientists. The two astronauts will also test systems and processes in preparation for the launch of the station’s core module in 2018. Two laboratory modules are scheduled to be attached in 2020 and 2022, when the Tiangong station is due to become fully operational. It is considered a stepping stone to a Chinese mission to Mars by the end of the decade.

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

Ozone saviour ban THE chemicals that saved the ozone layer, but then turned out to be an escalating threat to the climate, are facing a phase-out. Hydrofluorocarbons (HFCs) became widely used in air

ESA/ATG MEDIALAB

60 SECONDS

Fluffy ducky Rosetta’s comet is as weak as fluffy snow. Images from the probe show comet 67P is cracking under seismic stresses. That suggests its tensile strength is very low, and its distinctive duck shape will probably change in a few hundred years.

“They helped us out of a jam with ozone layer depletion. But it’s good news that they are being banned”

New depression drugs?

LI JIN/VCG VIA GETTY IMAGES

conditioning and refrigeration after 1987, when the Montreal protocol banned the use of the chlorofluorocarbons that were eating up Earth’s ozone layer. But on 15 October, a meeting in Mars rendezvous Kigali, Rwanda, of the 170 nations that signed the Montreal protocol NEXT stop, Mars. On 16 October at 1720 GMT, the twin spacecraft agreed to largely phase out use of of the ExoMars mission’s first HFCs by mid-century – because they are potent greenhouse gases. phase split in two – and if all goes to plan, one of them will be on They escape into the atmosphere the Red Planet’s surface by the during use and when equipment time you read this. is discarded. The two spacecraft, the Molecule for molecule, HFCs are 4000 times more potent than Schiaparelli lander and the Trace Gas Orbiter, separated shortly carbon dioxide. UN estimates after arriving on the outskirts of show that they were on course to Mars. The lander will head for the raise global temperatures by an surface, where it should make a additional 0.5 °C by 2100, and emissions of them were rising by “The Schiaparelli lander 7 per cent a year, faster than any will test a heat shield, other greenhouse gas. “It’s good parachute and propulsion that they are being phased out,” says Keith Shine of the University system on its way down” of Reading, UK. “But they helped smooth descent on 19 October, us out of a jam. We should give a while the TGO will slam on the vote of thanks to the HFCs.” breaks to enter into orbit. The ExoMars mission is a collaboration between the European Space Agency and Russia’s space agency Roscosmos. The long-term plan also includes a rover, which is expected to land on the Martian surface in 2020. This phase is crucial to the overall mission, because the TGO will act as a communications relay for the rover, and Schiaparelli will test some of its proposed landing gear. Schiaparelli is supposed to take 6 minutes to descend to Mars’s –See you in 30 days– Meridiani Planum. To inform

–Well on their way–

future missions, it will test a heat shield, parachute and propulsion system on its way down. Once landed, Schiaparelli will start monitoring wind speed, humidity, pressure and temperature, to help us understand Mars’s weather. “We are nervous, but excited as well,” says Francesca Ferri, a member of the Schiaparelli team.

Hospital infections NOT what the doctor ordered. The first study of infections acquired in hospitals in Europe has estimated that 2.5 million people caught one between 2011 and 2012 – that’s one in every 20 patients. “The most common were urinary tract infections, surgical site infections and pneumonia, each accounting for 20 per cent of cases,” says Alessandro Cassini of the European Centre for Disease Prevention and Control in Solna, Sweden. As well as causing an estimated 90,000 deaths, the infections also led to long-term conditions, including cognitive and physical impairment (PLoS Medicine, DOI: 10.1371/journal.pmed.1002150). The total health impact of these infections is thought to be double the combined burden of 32 contagious conditions caught outside hospitals, including flu and tuberculosis.

A class of anti-inflammatory drugs can relieve symptoms of depression, finds a review of studies of people receiving treatment for chronic inflammatory conditions (Molecular Psychiatry, doi.org/brxx). The drugs, called anti-cytokines, are used to treat rheumatoid arthritis, and may benefit people who don’t respond to standard antidepressants.

Fewer birth defects Older women who become pregnant with help from IVF or a fertility treatment called ICSI are less likely to have children with birth defects than those who conceive on their own, according to an analysis of 300,000 births (BJOG, doi.org/brxz). The team behind the study thinks this may be due to a beneficial effect of fertility drugs.

Cold truth about toms Putting tomatoes in the fridge ruins their flavour – and now we know why. Chilling stresses the tropical plant, irreversibly reducing activity of hundreds of genes, some of which are involved in giving tomatoes their aroma (PNAS, DOI: 10.1073/ pnas.1613910113).

Resupply success On Monday evening, US space firm Orbital ATK successfully launched an Antares rocket to the International Space station. The Cygnus spacecraft will berth with the ISS on 23 October and is carrying supplies and experiments. It is also bringing a lighting system designed to help keep astronauts’ body clocks in sync. The firm’s last Antares launch in 2014 exploded shortly after take-off.

22 October 2016 | NewScientist | 7

THIS WEEK

Lab-made eggs may cure infertility Jessica Hamzelou

PASCAL GOETGHELUCK/SCIENCE PHOTO LIBRARY

FERTILE, mature eggs have been created from mouse skin cells in the lab for the first time. The feat suggests that the same could soon be achieved in humans, opening up the possibility of new fertility treatments, and the potential for two men to genetically father a baby together. Katsuhiko Hayashi at Kyushu University in Fukuoka, Japan, and his team have been trying to mimic egg development in the lab. The group had some success in 2012, turning mouse skin cells into primary germ cells – a kind of immature egg cell in its early stages of development. But to finish developing, these cells had to be re-implanted into a mouse’s ovary. Now, the team has fully matured egg cells in a dish. Hayashi’s group started with mice of about 10 weeks old – some 30 years old in terms of human ageing. The team took cells from their tails and used an established technique to turn them into

8 | NewScientist | 22 October 2016

induced pluripotent stem cells, which can divide and form various types of cell. By placing these cells in a brew of specially selected compounds, the team encouraged them to become immature egg cells. But to fully mature, the cells needed help, says Hayashi – tissue taken from the ovaries of mouse fetuses. Placing a clump of fetal ovarian cells among the immature egg cells in the dish let them grow into mature eggs. In this way, the group generated more than 4000 mature eggs. To see if they were fertile, the team then fertilised some eggs with mouse sperm and implanted them in the uteruses of female mice. From the 1350 embryos they implanted, eight pups were born (Nature, doi.org/brxt). “It is a tremendous advance,” says Azim Surani at the University of Cambridge. “The idea that you can start with a skin cell and make viable eggs in culture is quite amazing.” It is likely to be only a matter of

time until the same feat is achieved with human cells. “From a technical point of view it could work,” says Hayashi. “If we could make human eggs, it could be a very powerful tool for curing infertility.” “If we can apply this to humans, we could almost eradicate infertility,” says Zev Rosenwaks at Weill Cornell Medicine in New York. “I’m extremely excited about this.” Jacob Hanna at the Weizmann Institute of Science in Rehovot, Israel, thinks this could be possible within five years.

The approach could also theoretically be used to create egg cells from men’s skin cells, raising the prospect of babies with two genetic fathers. “I get one email a day from same-sex couples asking me about this,” says Hanna. “Regulatory bodies would need to discuss this, but I fully support the idea.” Creating eggs from men’s cells is more of a challenge. Hayashi’s team has been trying to produce eggs from cells taken from the tails of male mice, but they tend to die at about the time of the crucial cell divisions that share out chromosomes in the right “I get an email a day from numbers among developing same-sex couples asking sex cells. This might be because me about babies with two having a Y chromosome – genetic fathers” the male-determining sex chromosome – disrupts this “You would have the unlimited process. But there may be ways ability to make eggs,” says Hanna, to overcome this problem, such who is part of a team that has as removing the Y chromosome, already made immature egg says Hanna. cells from human skin cells. There are other hurdles to If it works in people, the overcome before anyone can start technique could create eggs for generating human egg cells in a women who have become less dish. One issue is that Hayashi’s fertile with age or those who have team used fetal tissue in the low numbers of eggs, enabling experiment to give the egg cells them to have IVF. Women whose the final push to maturity. It is ovaries have been damaged, for possible that to do the same example by cancer treatment, with human cells, tissue from could also benefit. aborted fetuses could be used, but researchers are likely to need to develop an alternative method. It is also not clear how healthy the resulting eggs are. Only a tiny fraction of the embryos generated by Hayashi’s team made it through to live births. Of the eight pups born from skin-derived stem cells, two were eaten by their mother. There are many reasons why this might have happened, but it is possible it may have been because they were abnormal. “There are risks that we are willing to take with animals that we aren’t willing to take with humans,” says Craig Klugman, a bioethicist at DePaul University in Chicago. “I’m a man married to a man, but I’m not going to sign up to this until it’s a proven –An endless supply of eggs?– technique.” ■

In this section ■ Is it ethical to cull animals, and does it even work?, page 18 ■ First UK trial of driverless cars, page 23 ■ Wildlife Photographer of the Year winning image, page 26

SMALL island nations are at risk of severe drought as climate change causes sea levels to rise. Groundwater supplies are salinated as the sea swamps coastal areas, but there’s another problem inland, where fresh water is being pushed above ground and vanishing into thin air. As the seas rise, they not only lap higher up the beach but also raise the level of the groundwater – sometimes above low points on the surface. This can cause existing lakes to expand and new ones to form, which speeds up evaporation. “Lots of work so far has focused on coastal inundation,” says Jason Gulley at the University of South Florida in Tampa. “But there has been less focus on interior indentations that flood as sea-level rise pushes the water table higher.” Gulley’s team used computer simulations of islands similar to those in the southern Bahamas to show that such lake formation reduces groundwater resources more than twice as much as coastal inundation for a given amount of sea-level rise (Geophysical Research Letters, doi.org/brwx). “Arid regions are going to get substantial losses of fresh water,” says Gulley. Although just a small number of islands might be affected, the consequences could be severe, says Shannon Sterling at Dalhousie University in Halifax, Canada. “This is significant,” she says, “because reductions in available water are occurring in already water-limited sensitive areas, with potentially large economic and human consequences.” Gulley says the next step is to take his simulated results and figure out which real-life islands are most susceptible. But that will not be easy. “It’s more complicated than just predicting how much coastline will be flooded,” he says. “It will require deep, island-specific knowledge of topography.” Brian Owens ■

ENRICO SACCHETTI

New lakes drain drinking water as islands sink

Peter Plavchan at Missouri State University in Springfield. “There is perhaps no bolder claim that one could make in observational astrophysics than the discovery of intelligent life beyond the Earth,” says Andrew Siemion, the director of the SETI Research Center at the University of California, Berkeley. “You can’t make such definitive statements about detections unless you’ve exhausted every possible means of follow-up.” That is exactly what the Breakthrough Listen initiative – a project Siemion heads that searches for signs of intelligent life beyond Earth – will now do. The team plans to observe several –Twinkle, twinkle?– stars from Borra’s sample with the 2.4-metre Automated Planet Finder telescope at the Lick Observatory in California. Borra is excited that others are taking the reins. “Although our detailed analysis seems to IT’S a bold claim. Two which Borra says supports the indicate that it is a real signal, astronomers think they have idea that this signature is of it has to be validated with more spotted messages from not just extraterrestrial intelligent life. work,” he says. one extraterrestrial civilisation, He thinks that 234 distinct But the Breakthrough Listen but 234 of them. civilisations are beaming laser team is less enthusiastic. In a In 2012, Ermanno Borra at pulses of the same periodicity statement, they rate the detection Laval University in Quebec, towards Earth (arxiv.org/ as zero to 1, or insignificant, on Canada, suggested that an alien abs/1610.03031v1). the 10-point Rio Scale for the civilisation might use a laser for Borra and Trottier ruled out importance of SETI observations. interstellar communication. If the other possible explanations for Siemion thinks the spectral little green men flashed a laser the pattern, like rapid pulsations patterns were most likely caused towards Earth like a strobe light, by errors in calibration or data “We have to follow a we would see periodic bursts analysis. And Plavchan agrees. scientific approach, but hidden in the spectrum of their He points to several steps in the I strongly suspect that host star. Those bursts would be team’s data analysis that “scared faint and rapid, but mathematical it’s an ET signal” him” because they didn’t consider analysis could uncover them. how those steps might affect their “The kind of energy needed to in the atmospheres of the stars results – a red flag in any claim. generate this signal is not crazy,” themselves and light emitted The signal probably comes down says Borra. Laser technology from molecules in the star’s to a human error, he says. we have on Earth today could atmosphere. “We have to follow “It’s not a bad idea to look for a generate that kind of signal. a scientific approach, not an signal, it’s just that they didn’t do To check for such a signal of emotional one,” says Borra. their homework,” says Plavchan. extraterrestrial intelligence (ETI), “But intuitively – my emotion There is a ray of hope, though. Borra’s graduate student Eric speaks now – I strongly suspect The history of astronomy is Trottier combed through data that it’s an ETI signal.” chock-full of examples of an from 2.5 million stars recorded Others think Borra’s intuition unimaginable signal that led to by the Sloan Digital Sky Survey. might have run away with him. the discovery of new objects, like He found it, down to the exact “They don’t consider every pulsars, says Siemion. If it is not expected shape, in 234 stars. natural possibility and jump human error, the signal could Most of those stars are in the prematurely to the supernatural – point towards a new discovery same spectral class as the sun, so to speak – conclusion,” says in astrophysics. Shannon Hall ■

Strange signals from 234 stars could be ET – or not

22 October 2016 | NewScientist | 9

THIS WEEK

Michael Le Page

Beresford of the Teagasc Food Research Centre in Fermoy, Ireland. “But I had never thought about whether it occurs in the cheese environment.” The finding is based on genome comparisons. The team sequenced 30 bacteria they found in the rinds of traditionally aged cheeses from the US, Spain, Italy and France, although they would not say exactly which ones they sampled. They also used another team’s sequences of 135 species of bacteria found in French cheeses. Cheese-making initially relied on random colonisation by microbes from the environment. Once cheeses were matured in bulk in places such as caves, the microbes could escape from one

THAT cheese you’re so fond of is a hotbed of bacterial bestiality. The diverse microbes that cheesemakers use are swapping genes like crazy as they evolve to thrive in the new environment we have created for them. A study of 165 of the bacterial species in cheeses has found that 130 of them – 80 per cent – have shared genes with other species. Altogether nearly 5000 genes have been swapped. The process probably began when people started making cheeses, and continues to this day. And this level of sharing is probably an underestimate, according to Kevin Bonham of the University of California, San Diego, and his colleagues. Cheese “Could pathogens become more dangerous if they contains many bacterial and fungal species, so there could also steal the right genes from cheese bacteria?” be gene-swapping between fungi and bacteria, and among fungi (bioRxiv, doi.org/brwr). batch into the surroundings It is now clear that geneand then colonise new batches. swapping is much more common “They’re in the ripening room, than we thought, especially in the walls, in the air,” says among bacteria. “If you think Beresford. Bulk production has about it, it’s not that surprising,” encouraged microbes to thrive in says microbiologist Tom cheese by, for instance, picking up

Scan predicts your face after beauty therapy EVER wondered what you’d look like with your cheeks enhanced, or after Botox? A 3D-scanning technique may soon be able to show you. Michael Molton at Epiclinic, a clinic in Adelaide, Australia, began developing a 3D imaging technique after becoming frustrated with before-and-after photos. These are used to show prospective clients how 10 | NewScientist | 22 October 2016

a procedure may change their face, but the “after” shots are often enhanced with better lighting and make-up. “I wanted something that you couldn’t fudge,” says Molton – something like MRI scans. Molton used a 3D camera to take full-face scans of clients before and after they received dermal fillers, a popular injected treatment for plumping up the face. His team’s software then used the scans to generate a contour map showing which parts of the face had filled out after treatment. Molton has now tried this on

CHARLY TRIBALLEAU/AFP/GETTY IMAGES

Gene-swapping orgies… in cheese

–Ripe with iniquity–

new genes.“There’s been evolution going on for millennia,” says Paul Kindstedt of the University of Vermont in Burlington. Although the functions of most of the 5000 swapped genes are unknown, many help scavenge iron. That makes sense: one way animals try to limit bacterial growth is by depriving them of the metal. Milk contains lactoferrin, an antibacterial that mops up free iron. As a lack of iron is also what limits the growth of many disease-causing bacteria, this finding is slightly worrying. Could some microbes become

more dangerous if they stole ironscavenging genes from cheese bacteria? We don’t know yet. While the distinctive tastes of many cheeses – such as cave-aged Gruyère – depend on specialised microbes, it is possible to make cheese using microbes from just about anywhere – even your armpits. But some microbes can wreck cheeses they colonise. Beresford’s team recently found that a pink discoloration plaguing some cheese-makers is caused by Thermus thermophilus, whose usual home is hot springs. It may love being pasteurised. ■

200 people, and says it allows him to assess their treatment in a more accurate and unbiased way. This improved understanding has let his team develop an algorithm that predicts how someone will look after being injected with filler (Journal of Aesthetic and Reconstructive Surgery, doi.org/brwz). The team plans to test it with patients early next year. To predict the outcome of Botox injections, which alter how the face moves rather than its shape, the team is considering using 3D video instead. Software could analyse the

differences in how people smile, for example, before and after treatment. “Overall, I think this is positive,” says Gazi Hussain, vice-president of the Australian Society of Plastic Surgeons. However, he cautions that the technique may be used solely as a tool to attract clients, and that if people think they are being shown exactly how they will look, they may end up feeling disappointed. “We see this with rhinoplasty. Some surgeons use computer generations to show what their noses might look like, but you can’t always get that result surgically.” Alice Klein ■

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THIS WEEK

Proxima b’s star has a touch of the sun Cambridge, Massachusetts. The sun’s magnetic fields are thought to arise between two of its internal zones: an inner radiative zone and an outer convective zone. The zones rotate at different speeds, which roils the plasma at their boundary, generating a magnetic field. Every 11 years, these fields flip upside down. In between flips, the

IN AUGUST, we learned that the nearest star to our solar system is likely to have a rocky, Earth-sized planet orbiting it – and now the star, too, turns out to be more like the sun than we thought. Proxima Centauri is a red dwarf that was known to be just onetenth the size of the sun and onethousandth as bright. But it has been found to have a seven-year activity cycle, similar to the sun’s 11-year one. At times in the cycle, up to a third of its surface is pockmarked by starspots, which can produce flares. But unlike the sun’s relatively sedate flares, Proxima’s raging flares and outbursts of X-ray and ultraviolet radiation could prove deadly for any life on its planet, Proxima b. Because the star has a slightly different internal structure to the sun, it hadn’t been thought to experience the regular activity cycle of sun-like stars, says Brad Wargelin at the Smithsonian Astrophysical Observatory in

Overweight mothers have ‘older’ babies WOMEN who are overweight while pregnant are more likely to have babies who are biologically older than those born to women of a healthy weight. This could put the babies at a higher risk of developing chronic diseases later in life, and may reduce their life expectancy. Biological age is linked to the length of our telomeres – DNA that caps the ends of our chromosomes. Telomeres shrink every time our cells divide, and shorten throughout life. 12 | NewScientist | 22 October 2016

NASA/CXC/M.WEISS

Rebecca Boyle

“Short telomeres have been associated with cardiovascular disease, type 2 diabetes and atherosclerosis,” says Tim Nawrot at Hasselt University in Belgium. The length of a person’s telomeres at birth varies, and Nawrot and his team wondered if a mother’s weight might make a difference. They collected the BMI scores of 743 women who later became pregnant, and measured the length of telomeres in blood cells taken from the umbilical cord and placenta of their babies. The team found that the telomeres of babies born to overweight women were around 2.5 per cent shorter than those whose mothers were a healthy weight. And babies born to obese

sun cycles between minimum and maximum activity. At solar max, there are more solar flares and sunspots, while during the solar minimum, the sun can be so quiet that its face is spotless. But Proxima Centauri is a convective star all the way through, Wargelin says, so it shouldn’t have regular magnetic cycles. It should also constantly spew energetic particles in the form of flares, so it is known as a flare star. Those flares also make it tricky to study. As a result, previous attempts to nail down its activity have been inconclusive. To settle the question, Wargelin

and his team pieced together 15 years of data from an automated ground-based telescope network and the Swift, Chandra and XMMNewton space telescopes. As well as discovering that Proxima has a seven-year activity phase, they found that the star takes roughly 83 days to rotate (arxiv.org/ abs/1610.03447). During Proxima’s stellar maximum, one-third of its face is covered in starspots. At the sun’s maximum, by contrast, sunspots cover less than one per cent of its surface. “Flare stars are very spotty,” Wargelin says, which means the star would look dimmer to an observer on its nearby planet. Proxima’s magnetic activity drives stellar winds, plus X-ray and ultraviolet radiation, that could zap or blow away its planet’s atmosphere. Until we can peer at Proxima b directly – which may be several years away – studying the star’s activity will be our best way to understand what conditions might be like on the planet. “The stellar wind and highenergy emissions are driven by the magnetic field of the star, so you have to understand the magnetic field as a first step in understanding what’s happening to the planetary atmosphere,” –What’s going on inside?– Wargelin says. ■

women had telomeres that were 5.5 per cent shorter (BMC Medicine, DOI: 10.1186/s12916-016-0698-0). “In normal ageing, it takes 5 to 10 years to experience a shortening of 5.5 per cent,” says Nawrot. We do not know yet whether this effect could lead to shorter lives, or how maternal weight affects a baby’s

“Being a healthy weight whilst trying to conceive will have long-term benefits for a baby” telomeres. Nawrot’s team thinks excess fat might trigger inflammation, producing reactive chemicals that pass into a baby’s body via the

placenta and cause damage. But Catarina Henriques at the University of Sheffield, UK, isn’t so sure. Overweight people may already have shorter telomeres, she says, something they may pass on to their children via their genes, rather than through the placenta. If so, a father’s weight could play a role, too, although this needs to be tested, she says. In the meantime, women hoping to get pregnant may want to watch their weight. “Maintaining a healthy body weight whilst trying to conceive will have long-term benefits for the baby, giving it a head start with longer telomeres,” says Janet Lord at the University of Birmingham, UK.

Jessica Hamzelou ■

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IN BRIEF

First birds honked in dinosaur times

Frogfish turns ghostly white to match a bleached coral GOOD camouflage may require a speedy makeover, as this frogfish living on a bleached coral shows. Warty frogfish are sedentary seafloor dwellers that can change colour over a few weeks. By seamlessly blending in with their surroundings, they keep themselves invisible to prey. Since the warm waters off the Maldives abound in vibrantly coloured corals, the frogfish there typically sport matching orange or pinkish hues, says Gabriel Grimsditch of the International Union for Conservation of Nature Maldives in Malé. But rising ocean temperatures have led

to widespread coral bleaching (Coral Reefs, doi.org/brvr). Diving in North Ari atoll in May, Grimsditch and his team photographed an unusual white frogfish resting amid the bleached corals. Its dark protruding warts mimicked bits of brownish algae growing on dead parts of the coral skeletons. “It was fascinating, because we had never seen a frogfish that had changed colour to become white because of a bleaching event,” says Grimsditch. Frogfish rarely change location, so this individual had probably been in that spot for a while. It probably turned white as the corals bleached in late April or early May, when ocean temperatures were unusually high. Might it change colour again if the coral becomes overgrown with brown algae? “I would think it would – that would be my guess,” says Grimsditch.

Quadriplegic man feels with bionic hand BRAIN stimulation has made it possible for a paralysed person to experience the sensation of touch via a bionic hand for the first time. Robert Gaunt at the Center for the Neural Basis of Cognition in Pittsburgh, Pennsylvania, and his team achieved this by implanting electrodes in the brain of Nathan Copeland, a 28-year-old quadriplegic man. They were placed in the brain

region that registers touch from the hand, and linked to a robotic hand in the same room via a computer. Copeland’s brain was stimulated when the robotic hand was touched. “He feels these sensations coming from his own paralysed hand,” says Gaunt. When blindfolded, Copeland could correctly tell which of the robotic hand’s fingers Gaunt was touching 80 per cent of the time

(Science Translational Medicine, doi.org/brvz). This is the first time electrodes have been implanted in a person’s somatosensory cortex, the region that registers touch. Earlier work focused on the motor cortex, enabling paralysed people to use their thoughts to move bionic arms. But the ability to feel objects is vital for gripping and smoothly manipulating them – something Gaunt now hopes to marry with thought-controlled movement.

HONK if you’re a bird. Birds developed the unique vocal organ that enables them to sing more than 66 million years ago when dinosaurs walked the Earth, a fossil discovery shows. But the earliest syrinx, an arrangement of vibrating cartilage rings at the base of the windpipe, was still a long way from producing the lilting notes of a blackbird. Instead, the extinct duck relative that possessed the organ between 66 and 69 million years ago was only capable of honking (Nature, doi.org/brvv). All birds living today are descended from a family of dinosaurs that developed feathers and flight. The fossil suggests the syrinx is another hallmark of avian dinosaurs. “This finding helps explain why no such organ has been preserved in a non-bird dinosaur or crocodile relative,” says Julia Clarke at the University of Texas at Austin.

Toddler stars kick out their planets SINGLE-exoplanet systems may be the fault of their stars. Many stars appear to have only one planet crossing their face, and this may be their sole orbiting world. Now, Christopher Spalding and Konstantin Batygin at Caltech in Pasadena, California, argue that the rapid rotation of young stars may explain this odd setup. The spinning makes each star bulge in the middle, altering its gravitational field. That can cause it to toss most of the planets originally orbiting it out of its pen. Spalding and Batygin modelled the star Kepler-11, which has six known planets. Tilting the star and spinning it faster flung two to five of its planets into space after 1 million years (The Astrophysical Journal, doi.org/brv3). 22 October 2016 | NewScientist | 15

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IN BRIEF

ALEX HYDE / NATUREPL

THIS might not be a comforting thought. When you arrive home, the spiders can hear you. Gil Menda at Cornell University in Ithaca, New York, and his colleagues studied a type of jumping spider, Phidippus audax. It was thought to rely almost completely on sight and the vibrations it feels through objects like leaves or floorboards to sense nearby movements. But microelectrodes implanted in the spiders’ brains showed that their neurons responded to sounds such as chairs scraping and people clapping even when the noises were made between 3 and 5 metres away (Current Biology, doi.org/ brwq). “We were very surprised,” says Menda. “Our studies extended the range of auditory sensitivity to more than 3 metres – over 350 body lengths – for our spiders.” “All spiders have these hairs, so it seems likely this is something that lots of spiders can do,” says Menda’s colleague, Paul Shamble, now at Harvard University. The team has started testing other species of spider, and so far all of them seem to have a similar ability. “Spiders can hear humans talking and walking,” says Menda. “When I see spiders at my house or anywhere else, I find myself trying different tones to see if they respond, and sometimes they do.”

16 | NewScientist | 22 October 2016

Marine worms seen dabbling in gardening and farming plants WORMS have been spotted growing sprouts in their burrows, a type of cultivation never seen before in non-humans. Ragworms were thought to consume the seeds of cordgrass, an abundant plant in their coastal habitats. But the seeds have a tough husk, so it was a mystery how the worms could access the edible interior. Zhenchang Zhu at the Royal Netherlands Institute for Sea Research in Den Hoorn and his team have now discovered the worms’ surprising trick: they bury

the seeds and wait for them to germinate, later feeding on the juicy sprouting shoots. The sprouts are more nutritious than the raw seeds and are rich in protein, fats and amino acids. “The process of sprouting improves the digestibility and quality of the food,” says Zhu. To test the effects of sprout consumption, they gave 20 worms different diets. Those that ate sprouts gained more weight, growing by 25 per cent, compared with 5 per cent for those that stuck to raw seeds and

sediment (Ecology, doi.org/brvt). Ted Schultz, an entomologist at the Smithsonian Institution in Washington DC, thinks sprout cultivation could be important to the worms’ survival, and that this is a sophisticated adaptation because they must wait to harvest the food rather than consuming it immediately. “It’s the beginning of agriculture,” he says. The team suspects that earthworms are sprout-growers, too, because they are thought to supplement their diets with seeds. IMAGE SOURCE /PLAINPICTURE

Spiders can hear you walk and talk

Uranus may have two unseen moons WAVY patterns in Uranus’s rings may hold two small moons that orbit closer to the planet than any of its other satellites. The ice giant has 27 known moons – far fewer than the 67 and 62 of its neighbours Jupiter and Saturn, respectively. Its dark, narrow rings were first spotted in 1977 when they blocked the light from a distant star. Voyager 2 later discovered two moons, Cordelia and Ophelia, on either side of Epsilon, the planet’s outermost ring. The gravitational pulls of the two moons herd the ring particles into the narrow formation. Now Rob Chancia and Matthew Hedman at the University of Idaho, Moscow, have re-examined Voyager data and discovered wavy patterns in two other rings, Alpha and Beta. The team think these may arise from the gravitational tug of a tiny moon – 4 to 14 kilometres across – outside each ring (arxiv.org/abs/1610.02376). “It’s certainly a very plausible possibility,” says Mark Showalter of the SETI Institute in Mountain View, California, who has discovered moons around Saturn, Uranus, Neptune and Pluto. He hopes to use the Hubble Space Telescope to confirm the theory.

What to eat for less smelly farts IF YOU’RE feeling unpopular, try eating more bananas. A team of researchers has been experimenting with human faeces to discover which foods should make a person’s farts smell better. Chu Yao at Monash University in Melbourne, Australia, and her team found that mixing faeces with cysteine – a component of meat, dairy and other types of protein – causes a seven-fold increase in the amount of hydrogen sulphide gas – which smells like rotten eggs – that was released by the gut bacteria in the faeces.

“This explains why bodybuilders who consume lots of protein powder are known to have smelly farts,” says Yao. But resistant starch, found in potatoes, bananas, legumes and cereals, and fructans, which are found in wheat, artichokes and asparagus, reduced hydrogen sulphide by about 75 per cent. The findings, presented at a Gastroenterological Society of Australia conference in Adelaide last week, challenge conventional wisdom that people with stinky gas should eat less fibre.

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ANALYSIS ANIMAL CULLING

To kill or not to kill? Mass wildlife slaughters are routinely carried out around the world. Are they ethical and do they work, asks Alice Klein

LANGEVIN JACQUES/GETTY

BIOSPHOTO , JEAN-JACQUES ALCAL/BIOSPHOTO/FLPA JAMES WARWICK/GETTY

politicians, conservationists, farmers and animal-rights activists. Is it reasonable to kill animals if they threaten other species or are under threat themselves? There are three circumstances that justify lethal wildlife control, says Bidda Jones of animal welfare group RSPCA Australia. The first is if culling will save animals from an even worse fate. For example,

THE AGE/CRAIG SILLITOE

HIPPOS in South Africa, cats in Australia, deer in the US, badgers in the UK. Across the world, governments are announcing plans to cut back the numbers of some of our most-loved animals. The latest is a proposed cull of 250,000 Siberian reindeer – which could spread anthrax – just before Christmas. Such mass slaughter invariably sparks fierce debate between

18 | NewScientist | 22 October 2016

South Africa announced last month that it would kill some 350 hippos and buffaloes to prevent herds from suffering food shortages while the country endures a severe drought. Culling can also be necessary if other animals are harmed by a species out of control. Feral cats are culled in Australia to protect native wildlife. Kangaroos are also lethally controlled when their

numbers balloon, to prevent them from destroying vegetation that supports other species. Finally, animals that threaten livestock or human safety may need to be eliminated. In the US, overabundant deer are culled to prevent car collisions and Lyme disease transmission to humans. In the UK, badgers have been culled to slow the spread of bovine tuberculosis among cattle. And Norway has recently approved a plan to cull two-thirds of its native wolf population to reduce attacks on sheep. The ethical debate becomes murky when a decision must be made about which animals warrant greater protection, says Jones. “People have different values,” she says. Farmers value their livestock, conservationists often seek to protect overall biodiversity, which may require culling certain species, whereas many animal-rights groups believe that all killings are unjustified. Popular animals tend to attract the most vocal support, says Katherine Moseby at the University of Adelaide, Australia. The public backlash last year when the Australian government announced a plan to kill 2 million feral cats by 2020 is one example. “People love what they know – they have cats as pets and spend a lot of time around them and understand them,” she says. “But they’re not the ones out there seeing our native wildlife being slaughtered by cats every day.” Culling methods vary, from shooting in the head – seen as the most humane way because of its immediacy – to poison, traps and even specific viruses, but does the general principle actually work? Killing overabundant species seems like a logical strategy to reduce their impact, but it often backfires, says Chris Johnson, an ecologist at the University of Being popular doesn’t stop reindeer, hippos, kangaroos and badgers from being culled

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Tasmania, Australia. “In many cases, removing some animals actually increases the survival and reproduction of the ones that remain, and provides opportunities for new animals to move in,” he says.

Isn’t it ironic?

square-kilometre range. This large-scale approach prevented the camel population from rebounding, but was costly and labour-intensive. Is there a better way? Non-lethal solutions for managing wildlife are cheaper, more ethical and more effective, says Johnson. Instead of trying to minimise animal numbers, these approaches often focus on minimising their impacts. One example of this strategy is to plant more native grasses to make it harder for feral cats to catch small mammals that hide in them. In sparse, open landscapes that have been degraded by grazing and fire, 70 per cent of feral cat hunts are successful. But in thick, grass-covered areas, only 17 per cent of hunts succeed. Farmers have found that stationing guard dogs deters predators from attacking livestock. In a recent South

International hit list Animals across the globe have been, or are set to be, culled for a variety of reasons Canada 484 geese Excessive droppings

US 63 dee Combat Ly disease

UK 10,000 badgers Combat bovine TB

Norway 47 wolves Protect sheep

Russia 250,000 reindeer Reduce anthrax risk

Pakistan 700 dogs Prevent attacks on humans

This was recently demonstrated in Tasmania, when culling a third of the feral cats at four study sites led to population increases of Australia Cayman Islands between 75 and 211 per cent. 2,000,000 cats 3000 iguanas Protect native Protect native Remote cameras showed that species species as dominant cats were removed, more cats crept in from outside. Equally, a small-scale culling of Spain New Zealand South Africa ferrets on Rathlin Island in the UK 2700 mountain goats 10,000 rabbits and ferrets 350 hippos and bufaloes ended up doubling the population Protect native species Protect native species Avoid food shortages because the remaining ones had more resources, which encouraged additional breeding. measures – increasing vegetation difficult to trap or that spread Killing predators to cover, improving land conditions over large areas. protect livestock can also have and so on – can be implemented Genetic engineering techniques counterintuitive effects. A recent fairly easily,” says Moseby. “I think such as CRISPR could be used to US study found that the more culling has to stay in there as an alter sex-determining genes in wolves were culled, the more wolf “The more the wolves were option but we need to look at the invasive species so that all culled, the more attacks on broader picture.” attacks on sheep and cattle there offspring are male and sterile. sheep and cattle there were the following year. Attacks Some have suggested more This has been demonstrated in lab were the following year” on Australian cattle have also unusual ways to keep numbers mosquitoes, but hasn’t yet been been shown to be higher after down. Small studies have tested in the wild. “There are dingoes are baited. “The wolves or African study, cheetah attacks demonstrated that contraceptive obviously massive questions dingoes that move in are typically on sheep, goats and cattle implants can reduce the about whether it would be ethical solitary young males. They often stopped in 91 per cent of places reproductive rate of kangaroos, and what would happen if it got have a higher propensity to attack with guard dogs. but the approach is expensive and into areas where animals were livestock than the family groups “These sorts of indirect unsuitable for animals that are native,” says Moseby. that would be there if you just left Sophisticated non-lethal them alone,” says Johnson. control strategies may help to LETTING NATURE TAKE ITS COURSE The badger cull that began in appease our guilt over killing animals. For example, some native 2013 in the UK is on similarly shaky Now that we’ve wreaked havoc on animals, but we still don’t know native ecosystems by introducing Australian snakes have evolved ground, with no clear evidence if they will be effective or about foreign animals, there is a sense of smaller jaws since the introduction yet that it is reducing bovine their potential downsides. obligation to clean up the mess. But of poisonous cane toads in the 1930s tuberculosis cases. “Often these In the meantime, it is what if we didn’t try to remove the that reduce their ability to eat large things are done unthinkingly,” important to ensure that the invaders? toads containing lethal doses of toxin. says Johnson. “There’s very rarely control methods we use are Some ecologists believe that However, these are likely to be a proper evaluation of whether it scientific and thoroughly restoring ecosystems to their past rare cases, says George Wilson at will work and justify the cost.” evaluated. Killing wildlife is glory is impractical. Writing in Nature, the Australian National University. Lethal wildlife control can be often seen as a quick fix, but it a group of ecologists recently argued Almost 90 birds, 45 mammals and effective if it is widespread or won’t work, or it might backfire, that we should “embrace the fact of 10 reptiles have already been driven conducted on islands, so that if it is not done in the right way. to extinction by invasive predators, culled animals are not replaced by ‘novel ecosystems’ and incorporate Evidence-based non-lethal more from outside the region, says many alien species into management and the list of threatened species approaches such as landscape plans”. If a hands-off approach was continues to grow, he says. “The idea Johnson. For example, Australia modification also need to adopted, some native species could that you could just let nature run its recently successfully controlled become integral parts of wildlife evolve defence mechanisms that course is absolute nonsense – it’s its feral camel population by management plans. Not only will allow them to coexist with invasive ecological cuckoo-land.” shooting them from helicopters, this help us manage wildlife, it targeting their entire 1.3-millionwill also help us sleep at night. ■ 22 October 2016 | NewScientist | 19

COMMENT

A ban too far The US wanted to criminalise kratom, a leaf long used in traditional medicine. That would have been madness, says Marc T. Swogger WHEN the US Drug Enforcement Administration announced plans to criminalise the sale and possession of the psychoactive plant kratom, people across the country became interested in a leaf used medicinally for centuries in parts of Asia. What the DEA did not seem to know is that hundreds of thousands of people in the US were already taking it to relieve pain and as a substitute for opiates and other drugs. Kratom, related to the coffee plant, provides a caffeine-like energy boost at low doses and has opiate-like effects at higher doses, although it isn’t an opiate. In 2015, I led a study of people’s experiences with kratom. Reports were largely positive: besides pain relief and success in quitting drugs such as opiates, it gave a sense of well-being and relaxation, and increased empathy and sociability.

A minority reported negative effects, such as nausea, vomiting, dizziness, chills and sweats. About 10 per cent mentioned withdrawal symptoms, mostly relatively mild. Reviewing the literature, we read anecdotal reports of serious adverse effects coinciding with kratom use, including deaths involving use of multiple drugs. But the evidence is too sketchy to definitively link kratom with serious harm. The DEA wanted to put kratom on a fast track to criminalisation, without seeking public comment. Nonetheless, comment ensued. Thousands wrote to politicians, petitioned the White House and talked to the media about what they saw as an infringement of the right to use a plant that helps them. Researchers expressed dismay that research into kratom’s medical uses could be crippled. My colleagues and I could only

Power struggle Samsung’s exploding phones show how risky lithium-ion batteries can be, says Paul Marks EXPECTATIONS were high as the latest lightweight model hit the market – and initially all was fine. Users raved about its sleek curves, capacity and power. But then the lithium battery fires began and the brand took a knock. No, not Samsung’s Galaxy Note7 smartphone, whose blazing power cells saw the 20 | NewScientist | 22 October 2016

In January 2014, a 787 battery overheated at Tokyo’s Narita airport. Boeing’s answer was a better enclosure to contain any fire and an exhaust to jettison hot gas and smoke outside the plane. If such problems can strike an airliner, it is little surprise to see lithium battery failures in less safety-critical products. There have been a succession, in smartphones, laptops, hoverboards and e-cigarettes. One reason is that while these

product withdrawn worldwide last week. Rather, this was the Boeing 787, the carbon-fibre airliner whose launch was also dogged by burning batteries. In January 2013, a battery in an empty plane combusted at Logan “This will cost Samsung dear in the near term but Airport in Boston. A week later the knock-on effect is one caught fire in flight, leading to an emergency landing in Japan. incalculable”

batteries pack a punch in terms of power density, they can be volatile if treated badly. And “badly” can mean squeezed into more extreme spaces and shapes by the forces of fashion, as well as being bent, bashed and abused in use. Lithium-ion battery chemistry is highly sensitive to tiny structural failures: if separators keeping electrodes apart fail, a lot of heat is released quickly. This is almost certainly what happened at Samsung. In September, the firm blamed a manufacturing flaw for the Note7 fires. But a product recall and corrective action failed, so it pulled the phone entirely.

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Marc T. Swogger is associate professor in the psychiatry department of the University of Rochester, New York

This will cost Samsung dear in the near term but the knock-on effect is incalculable in its battle with Apple for customers. And so back to Boeing. Airline cabins are probably the worst place for a phone fire. In August, Boeing was granted a patent on a gas-venting fireproof briefcase into which cabin crew can drop, seal and extinguish a combusting phone, tablet, laptop or e-cigarette. If a company like Boeing is taking such a measure, that’s a sign Samsung’s meltdown is unlikely to be the last. ■ Paul Marks is a science and technology writer based in London

INSIGHT The right to choose

EMMANUEL DUNAND/AFP/GETTY IMAGES

shake our heads at the insanity of the move. In a land that jails more people than any other, with consequences that include ruined lives and children growing up without parents, we choose to criminalise this. In a country with an opiatedependence epidemic, we try to remove a tool that people successfully use to quit opiates, and one they take for pain relief instead of hard drugs. In a country that has suffered in a costly and ineffective “war on drugs”, we extend that war to a new substance and a new group of people, potentially worsening public health crises. It seemed cruel and irresponsible. Then something amazing happened. The DEA listened. It withdrew its plan, citing public opposition, and sought comment from doctors and scientists. The agency has long insisted, despite much evidence, that cannabis has no medical use. Does this uncharacteristic reversal over kratom signal it is giving a higher priority to facts? Let us all hope that it proves a positive development in the long, sad story of US drug policy. ■

–Women can handle this–

Timetoletwomen controltheirabortions Clare Wilson

abortion is illegal, with women buying the pills from online pharmacies. The advent of mail-order abortion pills means the law is becoming almost irrelevant. Not all pharmacy websites can be trusted, but one reputable site, called Women on Web, provides online medical advice along with the pills, and waives the €70 fee if someone can’t afford it. Requests for help from women in Ireland and Northern Ireland, where abortion is illegal in almost all circumstances, nearly tripled between 2010 and 2015, to 1438 a year, according to an analysis of the site’s

THROUGHOUT history, self-induced abortions have been a byword for horror, danger, even a grisly death. Many countries legalised abortion partly to eradicate them. But now we have the abortion pill. Up to the ninth week of pregnancy, women can safely have a home termination by taking two drugs over two days. The second dose of pills triggers bleeding and painful stomach cramps as the embryo is passed; this typically takes a few hours but can last several days. A few per cent of women need “For women who want to go to hospital to complete the a home termination the process. But it’s more or less like an pills should be available early miscarriage, which women can in pharmacies” usually cope with at home. The pills are also safer than many other medicines we can buy from figures this week (BJOG, doi.org/brws). pharmacies without a prescription. Despite the stress, over 99 per cent Viagra is available over the counter in of Irish and Northern Irish women said the UK, for example. So why can’t they could deal with their decision. women get abortion pills from This contradicts claims by antipharmacies and manage the process abortionists that abortions leave themselves at home if they choose? women destroyed by guilt. It might sound radical but it’s But even in countries where already widespread in countries where abortion is legal, we could copy

Women on Web to make terminations easier, simpler and quicker. In the UK, for instance, women must have two doctors sign them off and visit a clinic two or three times. That’s not always easy for those who can’t take time off work because they are in low-paid or insecure jobs, or have young children and no one to mind them. Then there are illegal immigrants, and those who must keep their abortion secret, such as women in abusive relationships. Of course some women want counselling to help them weigh up their options and this should always be on offer. But many just want to get it over with. So for those who want it, the pills should be available in pharmacies after a pharmacist has explained what to expect and what complications to watch out for. Failing that, a doctor’s prescription should suffice. At the very least we should allow clinics to give women the second dose to take home with them. This is starting to happen in many countries, and in parts of the US, but UK law says the pills must be taken in front of a doctor. UK abortion law is so archaic and bureaucratic it almost suggests we are making the process as difficult as possible to punish women for ending up in this situation. Rebecca Gomperts from Women on Web says, “It’s nothing to do with medical science, it’s about controlling women’s lives.” ■ 22 October 2016 | NewScientist | 21

TECHNOLOGY

Sierra sensing

JENNY E. ROSS/CORBIS DOCUMENTARY

Climate change has made California’s water supplies unpredictable. Covering the mountains with sensors could help, finds Hal Hodson

CALIFORNIA’S Sierra Nevada mountains used to be reliable natural water towers. Winter storms would coat them with a thick blanket of snow, which would melt as temperatures rose through spring and summer. Gravity carried meltwater down to cities for free. But climate change means water managers can no longer rely on the melt flow. Drought is the new normal, and snow falls less often and tends to come in bursts. In an attempt to take control of the state’s water cycle, a project called SierraNet is covering California’s mountains with networks of sensors. It will report snow and water conditions in unprecedented resolution, and allow monitoring of the unpredictable watersheds. The data will help California to manage its water and the hydroelectric dams that depend on it. “We’ve operated our water systems by the seat of our pants 22 | NewScientist | 22 October 2016

for the past century,” says Roger Bales, a civil engineer at the University of California, Merced, who jointly leads the project. “We’ve operated with very little information, because there was plenty of water and not that many people.” SierraNet distributes a mesh network of sensor packages that measure snow depth, humidity and air temperature, as well as solar radiation, soil temperature and soil moisture content. These sensor packs use a low-powered radio to relay the data they gather back through the mesh to a higher-powered base station. This makes sure readings get through even if one link fails, says Steven Glaser, an engineer at the University of California, Berkeley, and the other co-leader of the SierraNet scheme. “With a mesh you’re guaranteed that the data gets back.“ Glaser says he is working out

just say very, very, very low.” Over the last few months, PG&E has worked with SierraNet to carpet its Feather river watershed with sensors. It wants to use the new stream of data to help manage its dams. If the company knows how much water is sitting in the mountains, it can plan ahead and produce energy when the market most needs it. This is becoming increasingly important as California adds more solar panels and wind turbines to the grid – predictable and controllable electricity supplies are needed to fill lulls in renewable production. California’s drought and the accompanying drop in hydroelectric generation is costly –Better when it’s wetter– both for the economy and the environment, according to an a deal with Placer County Water analysis by Peter Gleick at the Agency that would fund ongoing Pacific Institute think tank in maintenance of the network, with Oakland, California. In the Placer using SierraNet’s data to four years to September 2015, help manage its water supplies. hydropower was down so much The lack of water and its that it cost Californian ratepayers unpredictable supply can play about $2 billion more over that period for their electricity, “We’ve operated our Gleick writes. “The additional water systems by the combustion of fossil fuels for seat of our pants for electric generation also led to a the past century” 10 per cent increase in the release of carbon dioxide from California havoc with hydroelectric power. power plants.” The Feather river in the Sierra Richards says gathering Nevada is usually flush with better data from watersheds is snowmelt in April and is relied a must-do for dam managers, on by hydroelectric dams. In 2015, because climate change means it was practically dry. that many of their models for flow “It was the lowest hydro no longer work. “The statistical production on record, probably,” models are having less and less says Kevin Richards, an engineer utility,” he says. at Pacific Gas and Electric, What it boils down to is that an energy company that the available water needs to be manages 360 megawatts of used more cleverly. “We need hydroelectric power on the to start managing the whole river, one of the largest hydro watershed, from headwater to projects in California. “Let’s groundwater,” says Bales. ■

BEN CAWTHRA/REX/SHUTTERSTOCK

For more technology stories, visit newscientist.com/technology

Lasers could prevent daytime drone crashes DRONES could soon be criss-crossing cities delivering pizza, cleaning windows and inspecting infrastructure, thanks to a sensor that will help them autonomously avoid hazards while flying at speed. InVisage Technologies of Menlo Park, California, has built a low-cost sensor called the SML20 that can rapidly detect obstacles up to 20 metres away. It exploits a technique called structured light, using laser pulses to project dots that are distorted by any object they strike. The reflected light allows the sensor to infer the location and distance of obstacles ahead. Previous structured-light sensors have worked poorly in daylight as the projected pattern is lost in the background glare. The new sensor solves the problem by using infrared lasers operating at 940 nanometres. Sunlight at this wavelength is mostly absorbed by water vapour before it reaches the lowest part of the atmosphere. The laser light reflected to the sensor is then detected by a layer of film made of quantum dots: nanoscale semiconductors engineered to react to specific wavelengths. These dots are five times more sensitive than the silicon-based detectors found in other sensors, enabling them to pick up reflections from lower-powered lasers. David Hambling ■

right now,”says Newman. “I think you will see autonomous vehicles rolled out in places like Olympic parks or central cities pretty soon, but it’s going to be a while before you can go into a garage and buy a car without a steering wheel.” Initially, 40 driverless pods will navigate the city’s 250-kilometre network of walkways and cycle paths, with a select group of passengers from the public. Over the next few years, the same tech

“Simply tell an app where you want to go, then a pod will pick you up and drive you to your destination” will be put on roads in Coventry, Greenwich and Bristol. The hope is that the pods can act like taxis. You will simply tell –Look, no hands!– an app where you want to go, then a pod will pick you up and drive you to your destination. Similar tech is popping up elsewhere. MIT spin-off company nuTonomy started testing driverless taxis in Singapore this summer, and Uber began field tests in pedestrian zone after all) and an Pittsburgh last month. on-board computer controls the A few recent high-profile steering to avoid hitting obstacles. accidents have put the spotlight The pod has a variety of cameras on the safety of self-driving cars, and sensors, including radar and but Newman says the technology the laser-based equivalent, lidar, just needs some time to develop. which collect information about Every year, over a million people the surroundings to help the die from road accidents due to vehicle figure out where it is in human error. Newman believes the pre-mapped environment. driverless cars can do better. “We don’t see a difference “There’s a whole class of errors between the road or the that computers never make,” pavement,” says Paul Newman, he says. “Self-driving cars never director of the OMRG. “The become inattentive, which is a vehicles always have to ask the big cause of human error.” questions, ‘Where am I? What’s Another possible advantage of around me? And what should I the system is environmental – the do?’ And we make sure that the vehicles are electric. As for worries systems are in place so that the about batteries running out, a cars have the answers.” group of pods could charge up It might not seem as sexy while the others are in service. as Tesla or Google’s driverless My test ride is a little bumpy projects, but the trial demonstrates and surprisingly creaky. As the how most people are likely to pod pulls up to our destination, first experience driverless cars: I feel a little underwhelmed. as a shared transit system in The journey was like almost any city centres. other that I’ve taken – but that, “We’re ready for the public perhaps, is the point. ■

Hail a pod in UK’s first driverless tech trial Timothy Revell

INVISAGE TECHNOLOGIES

I’M SITTING in the future of transport. It’s slow, tentative and totally autonomous. Driverless car trials have finally reached the UK, with two-seater “pods” zipping down pedestrianised streets in Milton Keynes. The purple-and-white vehicle, designed by automotive firm RDM, looks like a cross between a golf cart and a bubble. The doors open vertically, but inside it just looks like a regular automatic car hooked up to an iPad. It’s hard to tell that it has been kitted out with driverless control systems by Oxbotica, a spin-off company from the University of Oxford’s Mobile Robotics Group (OMRG). Tom Wilcox, a senior software engineer for the project, tells me he’s there to grab the steering wheel if something goes wrong. He taps the tablet and off we go. The pod accelerates to speeds of –Watch out for flying pizzas– 8 kilometres an hour (we are in a

22 October 2016 | NewScientist | 23

ONE PER CENT

TECHNOLOGY

Blood delivered by drone Drones fly medical supplies to clinics in Rwanda, finds Aviva Rutkin

ZIPLINE

drone will be loaded with up to 1.5 kilograms of supplies. When it arrives at its destination, it will drop the load, attached to a small parachute. The team says a trip that might have taken hours by car can be completed in under 30 minutes. It isn’t the first time that researchers have turned to drones to transport medical supplies. Last July, the US government signed off on a project to fly pharmaceuticals to rural Virginia using a hexacopter drone. Another project, run by California company Matternet, delivered medicine to a clinic in Haiti. If all goes well, the team plans to expand the drones’ cargo to include rabies vaccines, then perhaps other types of vaccine too. “When a child gets bitten by a rabid animal, it’s 100 per cent fatal,” says Siddiqui. “You need to actually have a vaccine at that particular point straight away.” It’s a great idea, subject to a few constraints, says David Salisbury at the Royal Institute of International Affairs in London. It’s important to make sure that the package gets exactly where it needs to go and that workers can confirm it has been received, he says. Another obstacle is that vaccines must be kept chilled within a narrow temperature range. But, if the trips are short, Siddiqui thinks they might not have to worry about vaccines going bad on the ride over. Ultimately, he hopes the project can expand to other countries too. “Our intention is to scale any intervention, any project that enables us to actually save lives and have access to vaccines wherever you are,” he says. “We –A drop of blood– think this can be one of those.” ■

24 | NewScientist | 22 October 2016

Wi-Fi kettle woes Fancy a brew? It took data analyst Mark Rittman 11 hours to get his Wi-Fi-enabled kettle to boil, a task he documented on Twitter as he tried to integrate the kettle with his other smart devices. “Well the kettleisbackonlineandresponding to voice control, but now we’re eating dinner in dark while lights download a firmware update,” he tweeted at the end of the ordeal.

120 terabits per second: the capacity of a new subsea cable being built by Facebook and Google to connect Los Angeles to Hong Kong. Google says that's enough for 80 million simultaneous HD video calls between the two cities.

Handle with care How best to return your Galaxy Note 7? Put it in a ”static shield” bag, then in one box, inside another box – and then inside a final, thermally insulated box. These were the instructions that Samsung sent with a return kit it began shipping after being forced to recall its Galaxy Note 7 amid reports of the phones catching fire and exploding (see page 20). XDA Developers uploaded a video of the kit to YouTube.

ASIF ADIA/MOMENT/GETTY

IN A warehouse outside of Kigali, difficult, especially when you Rwanda, 15 drones sit waiting come to the rainy season, where to receive a message. When the roads are just not an option.” text comes in, one loads up and That’s problematic for zips off into the sky – on a healthcare workers, who may not mission to save a life. have the supplies they need to Last week, the government deal with emergency situations – of Rwanda announced an such as postpartum hemorrhage, emergency drone delivery service. “When a clinic needs a These drones will make up to particular blood type, 150 trips per day, carrying blood they can send a text supplies to clinics in need. to the drone base” Rwanda has relatively good infrastructure in some places, but in others it can be unreliable, one of the leading causes of says Moz Siddiqui at the Global death for women in Africa. Alliance for Vaccines and Drones, says Siddiqui, are an Immunization (GAVI), one of elegant solution. Now, when three partners in the project, health workers at one of 21 clinics along with UPS and drone around the country need a company Zipline. “It’s the land particular blood type, they can of a thousand hills,” he says. send a text to the drone base, “In some areas, access is really nicknamed the Nest. There, a

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APERTURE

26 | NewScientist | 22 October 2016

Ape takes root YOU need a head for heights to survive in the jungle. The orangutan scaling this dizzyingly high tree is searching for figs – and he knows this is a good source. US photographer Tim Laman took this vertigoinducing photo in Gunung Palung National Park in western Borneo, and won this year’s Wildlife Photographer of the Year competition for it. To take it, Laman used ropes to climb the 30-metre-high tree and then spent three days rigging up GoPro cameras, which he triggered remotely when he spotted an orangutan hunting for food. The tree is wrapped by a strangler fig, which germinated in the tree’s canopy and then wound its roots down the trunk. Because orangutans carry a mental map of where the best fruiting trees are, Laman knew that a male he had previously seen nearby might well return. He was in luck, and captured this wide-angle shot as the ape shimmied up the fig plant’s roots, high above the jungle canopy. Figs are a vital food for the orangutans on Borneo, which are now critically endangered. Poachers kill an estimated 2000 Bornean orangutans (Pongo pygmaeus) every year, while illegal logging and uncontrolled forest fires mean they are rapidly running out of habitable jungle. The number of Bornean orangutans fell by more than 60 per cent between 1950 and 2010, and their numbers are predicted to fall by a further 22 per cent by 2025. Wildlife Photographer of the Year is developed and produced by the Natural History Museum, London, where the exhibition opened on 21 October. Niall Firth

Photographer Tim Laman Wildlife Photographer of the Year

22 October 2016 | NewScientist | 27

COVER STORY

WHAT ARE YOU WORTH? Each life is priceless. Except when it’s not, finds Shannon Fischer

I

F YOU had to put a price on your life, could you do it? What would it be? Where would you even start? We may think valuing human life this way is the stuff of darkest history, now confined to the malevolent underworld of human trafficking. We look with shame to an era when a human being could legally be bought and sold, their worth tied solely to the profit their work would yield. In the mid-19th century, before slavery was abolished in the southern states of the US, a “prime male field hand” could be purchased for about $1100 – roughly $30,000 in today’s money. Other human beings were bought and sold for far less. Our repulsion at the idea of putting a monetary value on people is consistent with the modern principle, outlined in documents such as the UN’s Universal Declaration of Human Rights, that all human lives are equal – and, we like to believe, equally priceless. Yet we routinely trample on those exalted ideals. The scientific literature and the news are both rife with examples of how unequally we value life – young over old, those like us over those who are different, the identified victim over the faceless masses. We don’t just value lives differently in a moral sense, but in real money. It is how we divvy up limited resources – from deciding how much to invest in building safer roads to setting compensation for families of soldiers and civilians killed in war, or those who were wrongfully imprisoned. And depending on

28 | NewScientist | 22 October 2016

who is doing the pricing and why, those numbers can vary, a lot. Life, it turns out, doesn’t have a price. It has a hundred. One of those numbers is a calculation of how much should be spent to prevent your death. To decide which potentially life-saving interventions are worth it, government bodies look at a quantity called the value of a statistical life (VSL), or as the UK Department for Transport (DFT) puts it, the value of a prevented fatality. “This is not the amount of money people would accept in exchange for certain death,” says W. Kip Viscusi at Vanderbilt University, Tennessee, who helped introduce the VSL to US agencies. “It’s really just a reflection of their attitude toward a very tiny risk of death.” Put simply, it’s the type of calculation we make when deciding whether it’s worth spending extra to buy the car with more safety features, just on a grander scale. Take the risk of dying from salmonella infection, for instance. If people are on average willing to pay $7 to reduce that risk by 1 in a million, then the VSL is $7 million. This would then be the figure used by the US Food and Drug Administration (FDA) to justify the cost of efforts to prevent salmonella outbreaks. The VSL a country adopts tends to vary with its wealth (as a benchmark, the Organisation for Economic Co-operation and Development recommends that member nations use a figure between $1.5 million and $4.5 million). Then there is the matter of how you >

PATRIK SVENSSON

22 October 2016 | NewScientist | 29

The biggest life insurance policy on record, bought by a mystery Silicon Valley billionaire

$201 million

determine what people would be willing to pay for a given reduction in their risk of dying. In the US, where the average VSL works out at about $9 million, economists make the calculation mostly by looking at what people do – wages someone accepts to take a risky job, for instance. In the UK, where the preferred technique is simply to ask people what they would be willing to pay, the DFT uses £1.8 million ($2.3 million). A 2009 report that compared the two approaches in Canada found that when the VSL is based on wages and risk, it’s worth about a third more. Based on reviews of both methods, Australia’s Office of Best Practice Regulation recommends a VSL of A$4.2 million ($3.2 million). VSL also varies with the cause of death being considered. In the US, it has ranged from $200,000 up to more than $13 million: reducing the risk of workers dying in a coal mine was worth more than reducing the

The sum of your parts Valuing a human life is one thing – but what about bodies? Whether it's a cadaver for medical research, a heart for an organ transplant or the elements we are made of, it's possible to work out a price Whole cadaver

$2450

Value of the elements in a 79 kg man*

$118,000 $28,600 Lungs (pair)

$1.04 million Heart

$1.24 million Liver

$739,000 Kidney

$334,000 (US) $62,000 (China) $6310 (Philippines) Egg

$18,200

Carbon

$54,200 Calcium

$34,500 Others

$19,200 …including Iron

$47.40 Oxygen

$10.70 Arsenic

$0.12 Gold

$0.05 Potassium

$6100

Sperm

Sodium

$640

$4000

SOURCES: ANATOMICAL ASSOCIATION OF ILL NOIS; MILL MAN; THE RED MARKET BY SCOTT CARNEY; ROYAL SOCIETY OF CHEMISTRY – VALUES OF ELEMENTS BASED ON PRICES FROM HIGH QUALITY CHEMICAL SUPPLIERS

30 | NewScientist | 22 October 2016

*speciically, Benedict Cumberbatch

Corneas

risk of death in a fire caused by your flammable couch upholstery. When you get into that other form of death prevention, healthcare, things only get more complicated. To decide whether medical interventions are worth it, healthcare providers and insurance companies consider how much decent-quality life you might get for the money. The measure they use is called a Quality-Adjusted Life Year (QALY): if 1 is perfect health and 0 is dead, then four years in middling health equals two QALYs. In the UK, one good year of life is worth around £20,000 to £30,000. That threshold is set by the National Institute for Health and Care Excellence (NICE), which oversees what new drugs or treatments the UK’s National Health Service can provide. To do this, it looks at the cost per QALY of new treatments compared with that of existing care. If a new drug offers one extra QALY for every additional £20,000 spent, that’s well within budget. “NICE focuses on that increment,” says Karl Claxton, a health economist at the University of York, UK, and a member of the NICE appraisal committee from 1999 to 2012. “What are the additional benefits, what are the additional costs, are they worthwhile?” Although NICE does make exceptions for particularly innovative drugs or end-of-life care, if costs start to push past £30,000 approval becomes much less likely. Sofosbuvir (sold under the name Sovaldi), the wonder drug for patients with hepatitis, made the cut. But bevacizumab (Avastin), a drug that could give certain cancer patients about three more months when given together with chemotherapy, did not. It cost at least £82,000 per QALY. The threshold NICE uses provokes controversy from time to time. That is in part because, as former NICE chair Michael Rawlins once conceded, it is not based on “empirical research” so much as “the collective judgment of the health economists we have approached across the country”. Since it was first put into use in 1999, there have been efforts to pin it to more robust research. But it remains as is, unchanged even for inflation. In countries such as Canada and New Zealand there is no explicit threshold. But when you analyse resource allocation decisions, in practice, it works out at roughly $15,000 per QALY. Contrast that with the situation in the US where, so long as an intervention is deemed “reasonable and necessary”, then the government-run health plan Medicare will not consider the cost. When you take into account that this could happen with a third-line cancer

Price per day to defend the lives of US presidential candidates

treatment costing $900,000 per QALY, it’s no wonder that the US spends nearly a fifth of its GDP on healthcare. Private insurers are not held to the same standards, and many clearly do consider expense – the more cost-effective a drug, the less their customers may have to pay out of their own pocket, for instance. But these systems are not always transparent and Medicare is still by far the largest healthcare funder in the country. Medicare does try to trim costs – or at least maximise benefits – in some ways, says James Chambers at Tufts Medical Center in Boston. They may only pay for drugs and devices for the sickest patients, for instance. But, legally, there is no straightforward way to do it. “There has been a view that you cannot, you cannot set a price on life,” says Louise Russell, an economist at Rutgers University in New Jersey who specialises in healthcare policy. “Which really comes down to, you can’t admit you have to.” Valuing someone’s life gets even harder once they are dead. Some guidelines exist when mortal danger is part of the job, but a huge number of variables remain. Members of the US military who die on active duty are entitled to a tax-free “death gratuity” of $100,000, a life insurance payout of up to $400,000, and a host of other benefits from burial costs to money for their children’s healthcare and education. By some estimates, the total can range from $250,000 to more than $800,000. The breakdown is similar in the UK, although much depends on the person’s salary and age at death. For police officers and firefighters, it is a similar patchwork of pensions, workers’ compensation, life insurance, union benefits and dedicated state and federal funds. One programme run by the US Department of Justice gives families a sum of $339,881. Outside of the line of duty, unexpected deaths reveal even more inconsistencies in how we value life. If compensation is settled in a wrongful death lawsuit, there’s a purely economic component that works out logically enough, based on estimates of the victim’s lost lifetime earnings, medical costs, funeral expenses and so on. But when it comes to >

PATRIK SVENSSON

$40,000

INHUMAN BUSINESS There are many legal ways we put a value on life (see main story), but there are plenty of illicit ones too. In cases of human trafficking, prices are often set based on the risk involved, transportation and labour costs and also market conditions. A child purchased in rural Africa for about $200 might later be sold for a far higher price, says Benjamin N. Lawrance, a historian and anthropologist at the Rochester Institute of Technology. That will depend on how many hands the child passed through on the way to say, mine shafts in another country, how many documents may have been forged for transport, and how many other desperate children arrived around the same time. Philosophical notions of human value have nothing to do with it. Similar factors influence

kidnapping ransoms. According to estimates from Terra Firma Risk Management, which advises families and employers of kidnap victims on conducting negotiations to free the hostages, a hasty abduction on the streets of Venezuela by criminals who put in the bare minimum of planning might net just a few hundred dollars. A more elaborate operation by syndicates and corrupt officials targeting a very wealthy individual might land a six-figure sum. “They’re looking at the hostages as commodities, like a businessman would look at something on his shelf,” says a spokesperson from Terra Firma, who asked to be kept anonymous. “The basic procedure is, they call and make a demand, then the other side makes an offer – a lot less – and all of a sudden, that victim is worth a certain amount of money.” 22 October 2016 | NewScientist | 31

grief and lost companionship, it’s all over the place. English courts limit bereavement awards to £12,980 total, far below NICE’s lower threshold for the value of one good year of life. This is derived from an early figure of £3500 set by Parliament in 1982. “It’s very arbitrary,” says Laura Hoyano, a human rights law specialist at the University of Oxford. “And it’s the very low level of it that’s probably the most insulting.”

In your absence In the US, compensation can vary by all sorts of factors, including the nature of the death, the amount of insurance held by those responsible, and even whether the sum is set by a judge, jury or two lawyers across a table. There is a lot of inconsistency, says Mark Geistfeld at the New York University School of Law. “How do you figure out how much my spouse suffers by way of loss of companionship if I die prematurely?” he asks. “Is that $100,000 or $100 million?” He says that judges tell juries there is no set way to do it, so jurors tend to look for some reference figure. “If somebody suffered $100,000 in medical expenses, maybe we’ll triple it, we’ll use that for an anchor, we’ll say pain and suffering will be $300,000.” Local laws also make a big difference.

The parents of 6-year-old Brandon Holt were compensated $572,588 after he was shot dead by another child in 2013. This was in New Jersey, where the wrongful death statute doesn’t allow juries to take the family’s emotional distress into consideration. In contrast, the wrongful death of 12-year-old Tamir Rice, who was shot by police in 2014 while holding a toy gun, was settled at $6 million. That case was decided in Ohio, where juries may consider mental anguish. The social context mattered here, too: Rice’s death was part of the broader controversy about black lives and the police. Ultimately, though, these cases did not attempt to value the lost life itself – nor does the law require it. Anthony Sebok studies these types of lawsuits at the Benjamin N. Cardozo School of Law in New York. “There’s damages for pain and suffering before you die, there’s damages for loss of income to your family after you die. But for the life itself that was lost, it’s worth nothing.” That’s why the context makes so much difference. After 9/11, the 2007 Virginia Tech massacre and the Boston Marathon bombing in 2013, attorney Kenneth Feinberg was tasked with distributing funds to survivors and families of those killed. The total amount available was different in each event, but individual payments weren’t meant to reveal

anyone’s fundamental worth. Instead they were an exercise in demonstrating patriotism, strength and the compassion of a people. After 9/11, the US government established a fund for injured victims and the families ofthe nearly 3000 dead. By Congressional mandate Feinberg had to follow certain aspects of wrongful death law, so he awarded funds partly based on the victims’ incomes; the next of kin of CEOs received more than those of janitors. But there was also a noneconomic portion, based on a flat rate: $250,000 per death, plus $100,000 for each surviving spouse and dependent. Payouts ranged from $250,000 to $7.1 million. “Congress wanted to demonstrate to the world its empathy and support for the victims,” Feinberg explained in his book, Who Gets What: Fair compensation after tragedy and financial upheaval. The programme was “proof positive that Americans stood together, a single community ready to help one another in our collective hour of need”. The money for the Virginia Tech and Boston Marathon victims was donated by individuals and businesses – “evidence of citizen compassion”, as Feinberg put it. So different rules applied: all lives were treated equally. Families of victims of the Virginia Tech massacre each received $208,000; families of those killed in the Boston

FOREVER YOUNG

32 | NewScientist | 22 October 2016

In an experiment, volunteers made choices about pairs of people who were diferent ages – which of the two should receive a life-saving organ, or whose death would be more tragic, for example. The graph shows the percentage of instances in which each age was prioritised

60 50 40 30 20 SOURCE: DOI: 10/BQ7J

as the fair-innings argument. “The basic concept is that everyone should have their fair shake at life,” says Landy. “The 50-year-old has gotten 50 years already, so we should save the 10-year-old.” Another way to frame it is the years-left argument – the younger person has more years of life ahead. But that reasoning only goes so far, because it turns out that our most highly valued humans aren’t newborn babies. That is because you develop more – and more profound – social connections as you age. There is also something of a “sunk cost” effect: “Older children have had more work put into them by their societies – the payoff has not come yet,” says Landy. The net effect is that we view adolescents or young adults as most worth saving. And, as they say, it’s all downhill from there.

Choice (per cent)

When it comes to what philosophers call negative rights – the right not to be killed, chief among them – studies show that at a fundamental level we do believe all humans are equal. But for positive rights, such as the right to be saved, we aren’t so even-handed. (See main story.) If there is only one dose of a life-saving treatment but there are two people who need it, how do you decide who gets it? A recent study done at the University of Pennsylvania by psychologists Justin Landy and Geoffrey Goodwin set out to answer that question. When volunteers were forced to make a series of choices between people of different ages, a clear, if unsurprising, trend emerged: we tend to favour the young over the old (see graph right). Why? When asked to justify their choices, people made what is known

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Compensation for 27 years unjustly spent behind bars in British Columbia, Canada

PATRIK SVENSSON

US$6 million

Marathon bombing each got $2.2 million. cases, the starting point per year spent in In theUK,theCriminalInjuriesCompensation prison is NZ$100,000 ($72,000). Authority handles payments to victims of In the US, different states have different violent crime. Their baseline number for a standards. In New Hampshire, it’s $20,000 death is £11,000 to one family member or total, no matter what. In Florida, exonerated dependent, or £5500 each if multiple people people get $50,000 per year served, to a deserve payment, plus extra for funeral maximum of $2 million. Robert Norris, a expenses, income loss and lost parental wrongful convictions expert at Appalachian guidance. There’s a £500,000 ceiling, but State University in Boone, North Carolina, says according to an investigation by the Financial that part of the value of this kind of payment Times, for victims of the London bombings in 2005, the highest award so far was nowhere “The view that you cannot near that: £141,050. set a price on life really Then there is the matter of people who spend years of their lives unjustly behind comes down to, you can’t bars. In the UK, there is no guaranteed admit you have to” compensation. Individual cases are assessed according to previous criminal record and lost income, among other things, but payment isn’t the money itself – it is recognition from tops out at £500,000, or £1 million if more the state that a mistake was made, even if that than a decade was served. That’s if it’s ever doesn’t amount to an apology. awarded. “They’re extremely strict,” Hoyano Western governments that compensate says. It’s not enough for a conviction to be families of civilians killed by their armed overturned – people essentially have to find forces in Afghanistan and Iraq use a similar new facts to prove their innocence to the rationale: the payments are not apologies so Ministry of Justice. The evidence bar is so high much as expressions of sympathy and regret. that many receive nothing at all. When Victor The UK Ministry of Defence paid £5600 to Nealon was released from prison in 2013 an Afghan man who lost his wife and son in after DNA evidence exonerated him from a a mortar bombing mishap; the German conviction of attempted sexual assault, he had government paid €3800 to each of 102 Afghan served 17 years. He got £46 in discharge money. families after a deadly bombing; the US paid In New Zealand, there is no legal right to $10,000 to the family of a brother and sister compensation, but awards are granted based shot at a checkpoint in Iraq. “It’s hard to on the merits of individual claims. In those digest that the value of a human life is a few

thousand dollars,” the retired US Army brigadier general Arnold Gordon-Bray said in an interview in 2013. “But you know that in their economic situation, it is the equivalent of much more, and you feel better.” It may be unsettling to think that the value we place on a human life shifts with political priorities, national boundaries and social context – that it differs depending on whether you are considering the cost of medication or safety belts. But just because it is difficult to place a fair value on human worth doesn’t mean that the attempt itself is unworthy. Consider Benjamin Franklin’s “moral algebra”. Nearly 250 years ago, Franklin wrote a letter to a friend facing a difficult decision. He recommended making a list of all of the pros and cons, and then striking out those on either side that seemed of equal importance. This early cost-benefit analysis was not meant to downplay the gravity of the decision, just the opposite. When “the whole lies before me, I think I can judge better, and am less likely to make a rash step,” Franklin wrote. The same idea applies today. Our reluctance to consider these most difficult calculations means we are left fumbling when we inevitably need to. “You make choices about what you spend on, there simply isn’t enough to do absolutely everything,” Russell says. “You can either make those choices with your eyes wide open, or you can do it with your eyes shut.” ■ Shannon Fischer is a writer based in Boston 22 October 2016 | NewScientist | 33

MARK STEVENSON/STOCKTREK IMAGES/GETTY

Life’s subatomic secret The cryptic nucleus that gives rise to life is weirder than we thought, says Marcus Chown

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34 | NewScientist | 22 October 2016

of carbon that exists in the universe. The other possibility is that three helium-4 nuclei come together simultaneously inside bloated, dying stars known as red giants, where all the hydrogen has burned off to leave an extremely dense and hot core of helium. But this process is so rare that even over the aeons since the big bang, it couldn’t have produced enough carbon. So how did we end up with so much of the stuff? That remained a mystery until 1953, when astronomer Fred Hoyle made an audacious prediction. He said that there must be an excited state of the carbon nucleus – a particular configuration of the protons and neutrons – with precisely 7.65 megaelectronvolts (MeV) of energy above the minimum, or ground state. In an excited state, the particles at the heart of an atom jiggle around more vigorously than they do normally. The laws of quantum theory permit only a limited set of stable energy states. At most energies, the nucleus falls apart. Why, then, did Hoyle make such a precise prediction for the energy of his proposed state? The answer is that 7.65 MeV represents

THOMAS IMO/ALAMY STOCK PHOTO

OU are made of carbon. So are your pets and all your houseplants. Every living thing on Earth owes its existence to carbon atoms’ ability to join up with other elements in a bewildering number of ways and form complex molecules. But the abundance of this element in our universe depends on a seemingly miraculous coincidence – an excited state of the carbon nucleus that our best models say shouldn’t exist, but clearly does. The nature of this weird form of carbon has baffled us for more than 60 years, much to the distress of nuclear physicists. Its existence is so essential in the sequence of reactions making life possible that our failure to explain it is deeply embarrassing. “We need this state to exist for us to be here and yet it is extremely unusual in nuclear physics terms,” says David Jenkins at the University of York, UK. “Cracking this problem has become a matter of pride.” And yet the more we learn, the more confusing things seem to become. The story starts 13.8 billion years ago, when everything erupted out of nothing – or at least the ingredients for everything did. Actually, the only elements forged in the big bang were the very lightest: hydrogen, helium and a smattering of others. All the heavy stuff, starting with carbon, was forged later inside stars. The first step in carbon manufacture is to fuse nuclei of the lightest element, hydrogen, to make the second-lightest, helium. The next step ought to be for two helium-4 nuclei – each containing two protons and two neutrons – to fuse to make beryllium-8. This would then grab another helium to make carbon-12. Except there is a snag. Beryllium-8 is highly unstable, meaning it decays in the blink of an eye – too quickly to produce the amount

Red giant stars conjure carbon, and gigantic computers (below) are helping us figure out how

the combined energy of three helium-4 nuclei whizzing about at 100 million degrees, the temperature at the heart of a red giant. This, Hoyle realised, would create a “resonant” reaction: rather than ricocheting off one another because they have too much energy to make carbon-12, the three helium nuclei become much more likely to fuse in a twostep process and store the excess energy in the jiggling of protons and neutrons. After that, the excited nucleus can decay into everyday carbon-12. Observations from collider experiments soon proved Hoyle right. It was an astonishing triumph, and remains the only successful prediction based on an anthropic argument ahead of experiment – that is, “I exist, therefore it must exist.” For Hoyle, it was also evidence that our universe must have been fine-tuned for life. If the energy of the Hoyle state, as it is now known, was slightly above or below that of the three helium-4 nuclei, there would be no carbon-based life. The fact that it happened to occur exactly where we need it to exist suggests an exceedingly fortunate coincidence. Either that or it’s evidence that

show that the 12 nucleons adopt a semi-stable state at roughly 7.65 MeV, the Hoyle state. A couple of years later, they used a similar technique to calculate the structure of the Hoyle state. They found that rather than 12 nucleons buzzing about independently, it takes the form of a cluster of three helium nuclei – each containing two protons and two neutrons, and often referred to as alpha particles – arranged in a boomerang shape.

Quantum shift

our universe is one of many in a multiverse, where all other possibilities also occur. Then again, theorists have recently pointed out that in stars in alternative universes with different versions of the laws of physics, beryllium-8 could be stable. That suggests it may be easier to make carbon elsewhere. Back in our own universe, the problem that persists more than 60 years on from the discovery of the Hoyle state is that we still don’t know what it looks like. How are the protons and neutrons, collectively known as nucleons, arranged to retain stability at this particular energy? Perhaps nuclear physicists shouldn’t feel too sheepish about their slow progress. The hard truth is that calculating what all the protons and neutrons inside a nucleus are doing at any one time is a devilishly complex task. Using rough models of how nucleons interact under the forces that bind them – the strong nuclear force and the electromagnetic force – physicists can accurately describe the structures of many nuclei. But the Hoyle state does not arise from any of these models. One way to crack the problem is with brute force: to take what we know about the strong

and electromagnetic forces to calculate how the particles inside the carbon-12 nucleus arrange themselves in the Hoyle state. For a long time, that seemed impossible. With carbon-12 containing 12 nucleons, each containing three fundamental particles called quarks, there were too many interactions to consider. We just didn’t have the computing power to solve that many equations. But in 2011, thanks to the numbercrunching might of a supercomputer called JUGENE and a neat mathematical trick that

“One way to crack the nucleus that gives rise to life is with brute force” allows us to ignore the quarks, a team led by Evgeny Epelbaum at the University of Bochum in Germany finally made what appeared to be a breakthrough. Every split second, JUGENE summed up the forces exerted on each nucleon by its 11 companions, adjusting each one in response, and repeating the process over and over again. It took weeks but Epelbaum and his colleagues were able to

Job done? Not a bit of it. For starters, the semistable state of carbon-12 simulated by JUGENE was a few per cent off the precise amount of energy contained in the Hoyle state. That means there is still a little way to go to predict it from first principles with perfect accuracy. More confusingly, when it comes to its internal structure, recent experimental work suggests other possibilities. In 2014, a team led by Martin Freer at the University of Birmingham, UK, fired a beam of alpha particles at a carbon target to produce carbon-12 nuclei that spin so fast that they throw off alpha particles. By measuring the properties of this shrapnel, the team was able to reconstruct the energy levels of carbon-12, and came up with a different conclusion: that the alpha particles in the Hoyle state are arranged in the shape of an equilateral triangle. The Extreme Light Infrastructure facility, under construction in Bucharest, Romania, should help to settle the matter. It will scatter laser light off accelerated electrons to create high-energy gamma rays whose energy can be tuned with exquisite precision. The plan is to zap the carbon nucleus, then note at what energies it falls apart and what it falls apart into. “Basically, the idea is to confirm the Hoyle state by destroying it,” says Jenkins. Already there are fresh hints of oddness. Last month, Ulf Meissner at the University of Bonn in Germany and his colleagues showed that certain light nuclei exist near a quantum phase transition, the quantum equivalent of the threshold at which ice melts or water boils. It is the first demonstration that nuclei can switch between two phases: one a strange gaslike state of matter, in which the constituent particles hardly interact, and the other more like a liquid, in which they do. This raises the possibility that the Hoyle state might exist on this boundary, making it even weirder than anyone suspected. ■ Marcus Chown is author of What a Wonderful World: Life, the Universe and Everything in a Nutshell 22 October 2016 | NewScientist | 35

GEORGE KONIG/KEYSTONE FEATURES/GETTY

Once hunted to near-extinction, the North American beaver is making a comeback

Could nature’s engineers help save California from drought? Macgregor Campbell finds out

MICHEL ROGGO/NATUREPL.COM

BEAVER FEVER G

OLD wasn’t what drew the first European settlers out West. The California gold rush was preceded by the California fur rush: having exhausted what nature could supply in Europe and in the eastern American colonies, trappers set out in search of new riches. The thick, lush coat of the North American beaver was particularly prized. It was traded for every commodity under the sun, shipped around the world and used to make clothes and hats. How fortunes change. The fur rush drove the North American beaver, Castor canadensis, to near-extinction. Then, after a remarkable comeback last century, the once-prized rodent became a pest. Now, some say it could be on the cusp of a fresh rebranding: not as a prize or a pest, but as a prodigy. 36 | NewScientist | 22 October 2016

Known as nature’s engineers, beavers seem to magic water out of nowhere. Crucially, their dams also help to store that water. At a time when California faces endless water shortages and long-standing drought, could beavers be part of a more natural solution? Like much of northern California, the area around Sugar Creek, just off state route 3, was once dredged for gold. Streams were forced into channels and wetlands drained. As a consequence, metres-high mounds of bare river rock now bake in the sun. But tucked away in the midst of all this rubble, a curious scene unfolds. Shrubs swallow the rocks, bulrushes stand in a wide expanse of clear, still water, and cottonwood trees tower over the landscape. In the speckled shadows, yellow butterflies dip

and soar while finger-sized blue dragonflies perch on reeds. Translucent baby fish take cover under waterlogged sticks. Beavers and humans have been busy. “We’re building an ecosystem here,” says Michael Pollock, a researcher with the National Oceanographic and Atmospheric Administration (NOAA), based in Seattle, Washington state. In 2010, local landowner Betsy Stapleton got in touch with Pollock after reading about some of his research. Pollock was interested in something called beaver dam analogues. Typically consisting of a line of posts set across a stream bed and interwoven with willow and cottonwood branches, these faux dams slow water down and widen out a stream to form a pond. The goal? To attract beavers. Putting one up is like prepping beaver real estate for sale.

In Sugar Creek, much to Stapleton’s delight, the faux dams worked. As she wades through soft muck into surprisingly pristine pond water, she points out evidence of beavers all around. Sticks with chew marks are strewn across the pond bottom. A scent-mound of dried mud stands guard telling interlopers that the pond is spoken for. Vegetation has been stuffed into both dam analogues. “They like to plug every little hole,” says Stapleton. For Pollock, Sugar Creek was a test case for a new way to manage water. When Stapleton first contacted him, the site had just a trickle of water. It felt symptomatic of the wider issues facing California, namely persistent drought and dwindling groundwater resources, neither of which is likely to be eased by climate change. Traditionally, the answer

has been to build more channels, reservoirs and other artificial water infrastructure. Pollock believes beavers are a better solution.

Parachuted in The idea isn’t new. In the 1950s, fish and game officers in Idaho parachuted nuisance beavers into new areas, far from humans, where they might be able to help with flood control and habitat restoration. Unfortunately, the impact of this work was seldom rigorously followed up. Humans thought of beavers primarily as a problem – out of sight, out of mind. Later, in the mid-1980s, a wildlife biologist with the US Bureau of Land Management called Larry Apple attached old truck tyres to small beaver dams and watched as the animals

happily integrated them into their structures. Then, in the early 1990s, came an accidental experiment. Fish and game officers in Elko, Nevada, were working with ranchers to restore two dried-up stream basins that cattle had obliterated. To recreate a habitat for cutthroat trout, they put fences up – fish on one side, cows on the other. Willow, a favourite beaver food and building material, took root. By 2003, a colony had moved in and begun damming the streams. Before long, the dry creek beds had sprouted into verdant wetlands, which attracted other animals too. It was never the officers’ intention to lure beavers to Elko, but the events proved that under the right conditions and with very little money, beavers could completely transform an ecosystem. > 22 October 2016 | NewScientist | 37

That same process is now at play at Sugar Creek. The adjacent, undammed creeks are dry in the summer. When they do flow, in autumn and winter, the water moves fast, washing all the dust and nutrients they pick up out to sea. Come summer, it’s just dry gravel again.

Water from nowhere

JOEL SARTORE/NGS/GETTY

HERE’S LOOKING AT CHEW How could you not love beavers? They are intensely social and form lifelong pairs. Each family – or colony – splits its duties: while one animal gathers building material, another excavates the pond and yet another watches the kits (that’s a baby beaver to me and you), keeping an eye out for predators or rival colonies. A single family can create and maintain tens of square kilometres of water infrastructure. They thin local forests, both for building material and bark – their preferred food – and store it in underwater caches of sticks and small logs that also provide homes to baby fish. Beavers have webbed feet, transparent eyelids and closable ear and nose-valves, all perfect for their largely aquatic lifestyle. There’s also an inner lip behind their impressive incisors, allowing them to chew underwater without drowning. They tirelessly put together dams, build the lodges they live in, excavate ponds and connect them with canals. Their aim is to create large ponds so they can spend as little time on land as 38 | NewScientist | 22 October 2016

possible. This puts their main predators – wolves, mountain lions and wolverines – at an instant disadvantage. It also encourages aquatic vegetation, which provides food and building material. Plus, dragging a 6-metre log around on the ground is tough work, but put that same log in a pond and the dog-sized rodent can push it around with ease. Their tails are incredibly versatile. Not only do they help with deft underwater acrobatics, they are also slapped against the water to warn the colony of imminent threats. Beaver tails store fat for the winter, which made them a delicacy during the fur trade days. They also prop their owners up so they can chew on trees, and have an ingenious circulation that helps regulate body temperature. Perhaps the beaver’s most surprising attribute is its anal scent glands. They produce a substance called castoreum, which beavers use as a calling card. Humans use it in perfumes and occasionally as a flavouring additive, typically in substitutes for vanilla.

At Sugar Creek, on the other hand, the water gets stuck. Beneath it isn’t just rock but rich soil too. NOAA hydrologist Brian Cluer points out sand and fine dirt that has come from further upstream. In the still waters of the ponds, it settles. Grasses, reeds and other plants take root in the stuff, locking it and its moisture in place. With time, a thick base of rich, moist soil builds up, helping to raise the water table. Cluer says that all this has a huge knock-on effect. The water seeps down into the ground, recharging underground aquifers. That matters because California is depleting its groundwater at an alarming rate. It is now tapping into “fossil” water that has been underground for tens of thousands of years. Farmland is sinking as aquifers collapse. This is the price you pay for an intensive water management system predicated on drained wetlands and artificial channels, says Cluer. Slowing water down and storing it in natural ecosystems could be much more effective than creating reservoirs, where half the water evaporates, he says. And although beaver dams will never reverse the damage caused by increasing greenhouse gas emissions, it could help keep at least some of the water from the rapidly melting California snowpack on land – instead of letting it run out to sea each spring. There’s good reason to believe this. Ten years ago, Glynnis Hood, a wildlife ecologist at the University of Alberta in Canada, and her colleagues systematically reviewed aerial photos of the province, taken between 1948 and 2002. Beavers returned in 1954, so the team could quantify their impact on the landscape. Sites recolonised by beavers had nine times as much surface water as before they came back, even in years of drought. The beavers proved more influential than climatic variations like temperature and precipitation. Given the scale of the water problems facing the western US, beavers seem like a cheap and scalable solution, says Joe Wheaton at Utah State University in Logan, who has worked on beaver restoration efforts in Utah, Oregon and elsewhere. He says rather than spend billions to redirect streams and build a few big dams,

Where there’s beavers there’s water: putting in the foundations for new dams at Sugar Creek allowed beavers to create a lush ecosystem

SCOTT RIVER WATERSHED COUNCIL

the government could build tens of thousands of smaller dams for far less money and get beavers to maintain them for free. “They just need a little water and a little wood. They can survive and make a decent living in a huge variety of situations,” he says. It’s not all sweetness and light, however. Humans and beavers working in harmony to restore degraded ecosystems is an alluring dream, but the reality is somewhat more complicated. For one, there’s a reason why beavers are considered a nuisance: they don’t always do what you want them to. Introduce them in the wrong area and they can wreak havoc. Chewed trees, plugged culverts, flooded fields and roads – the same behaviours that make beavers excellent engineers are often at odds with human infrastructure. Across the US, that means damage costing tens of millions of dollars each year. Introducing beavers to an area doesn’t always go well for the animals either, says Jimmy Taylor, a wildlife biologist with the US Department of Agriculture, based in Corvallis, Oregon. Dropping them into a new area can leave them vulnerable to predators and without enough food while they build their infrastructure. Taylor points out that many beaver ranges have recovered since the fur trade ended. If a seemingly beaver-friendly area isn’t already home to some, there’s probably a reason. Maybe there are predators, or perhaps the food and wood supplies aren’t right. Or the area could already be claimed: conflict between colonies can force one to migrate, possibly into areas where humans live. “It may be that the area we think is suitable, really isn’t,” he says. In his view, “when humans relocate animals, it’s almost always a failure”. Taylor knows this from experience. He and his students recently trapped and relocated 38 nuisance beavers near the Oregon coast. Sixteen weeks later, more than half had died, many eaten by mountain lions. The dams they built were ephemeral and washed away in the higher winter flows. It’s not just resident beavers who dislike interlopers – people living in the area often object. Wheaton says one project in Escalante, Utah, was met with fierce local opposition from ranchers who saw the rodents as pests. To get around situations like this, his team have been building a software mapping tool to help predict where beavers might thrive and stay out of humans’ way. It identifies areas where water flows are conducive to beavers and cross-checks them against human infrastructure. They are using the tool to see

how big an impact beaver restoration might make in the western US. Minimising conflict between beavers and humans is a good start, but not the whole story. Some fish and wildlife managers are concerned that the dams obstruct fish and so will harm stocks. Pollock doesn’t buy the argument. Together with Wheaton and others, he has recently completed a large-scale study

“Areas recolonised by beavers had nine times as much water as before” of the effect beaver dams have on steelhead trout numbers at Bridge Creek in Oregon. In 2008, the team started building beaver dam analogues along a 32-kilometre stretch of the watershed, eventually completing 121 by 2012. The resident beavers chipped in, building on top of the artificial dams and creating new ones too. By 2013, there were 236. Before the experiment, the density of fish living in Bridge Creek was the same as at nearby Murderer’s Creek, but by 2013 it was

nearly double. It seems that far from being harmed by the dams, fish were benefiting from the wetter, more protected environment. What’s more, so far as the team could tell, there was no change in the number of adult fish heading upstream to spawn. They seemed to have no trouble hopping over the dams. “Beavers and salmon have been evolving together since at least the Pliocene, 3 million years ago,” Pollock points out. He says preliminary results at Sugar Creek tell a similar story. Before the beaver dam analogues, they counted tens or hundreds of baby fish in a typical summer. After? Thousands. “There’s way more than we can count,” says Pollock. Life at Sugar Creek is sweet indeed. But will it last? Part of a dam washed out downstream during last winter’s high water. Standing in the middle of the pond with water up to her hips, Stapleton points to where the 4-metrewide breach was. The beavers have patched it up with sticks, reeds and mud. The waterstoring, soil-building fish factory is fine. She smiles. “What’s not to love?” ■ Macgregor Campbell is a writer based in Oregon 22 October 2016 | NewScientist | 39

HEINZ TROLL/EUROPEAN PATENT OFFICE

The day the world became 3D The most creative moment of the 1980s has nothing to do with eyeliner or electronic music. Chuck Hull recalls the moment he invented 3D printing

40 | NewScientist | 22 October 2016

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round the world, thousands of people who are missing limbs are wearing custom-fitted replacements. In operating theatres, surgeons are using 3D replicas of their patients’ bodies to guide operations. That’s the kind of thing that makes Chuck Hull very, very happy – because he invented the technology that made it possible. “I’ve been the most surprised and impressed by the advances 3D printing has enabled in healthcare,” Hull says. “It’s an amazing feeling to contribute to saving and improving lives on such a fundamental level.” Thirty years ago that was unthinkable. Making things like prosthetic limbs – or even plastic widgets – was notoriously difficult. “Every engineer knew how tedious it was,” Hull says. “You would design a part and make blueprints that you give to a designer. Then you need a machinist. Then, finally, you’d go to the injection moulder.” And if it wasn’t right, you had to go through the whole process again. Manufacturers were desperate for a

PROFILE Chuck Hull is founder and CTO of 3D Systems, based in Rock Hill, South Carolina. He patented the stereolithography process in 1986

From humble beginnings: the first machine built by 3D Systems (right)

better way. “Nobody had a solution for this – and that was the point of 3D printing,” Hull says. “The idea was simply to prototype plastic parts. It doesn’t sound very imaginative given how exciting 3D printing has become.” Hull is being typically modest: back in 1983 his idea was a flash of inspiration. At the time, he was working for a small US company using high-intensity UV light to set, or cure, liquid plastic into solid. One of its products was a coating for a table. “At some point it occurred to me that we were curing really thin pieces of plastic,” Hull says. “I thought, maybe there was some way I could stack up these sheets to create prototype parts.” If he could make it work, it would slash production times from months to days. “I went to the head of the company all excited, saying, ‘Hey, we’ve got to work on this’.” He didn’t get very far. Despite Hull’s enthusiasm, his boss was reluctant to gamble valuable resources on a future in layered plastic. But Hull kept arguing his case. “I was

confident that I could figure out how to do it,” he says. Eventually, his boss agreed to let him have an empty lab at the back of the building. But he couldn’t use it in company time. He had to work on the idea at evenings and weekends. He started with the motors found in pen plotters – machines that draw things like building plans – and programmed their motion on a primitive computer using BASIC. It was laborious work. “You had to envision it in your head and program in, line by line, the routine for the shapes you wanted,” he recalls. To make the objects themselves, he focused two UV lights on a vat of liquid plastic and used two motors to guide the light across its surface, solidifying a sliver of plastic into a flat shape. The third motor then lowered the solidified piece, submerging it in liquid plastic again, ready to add the next layer. At first, Hull struggled to get the layers to stick and the shapes to hold together. “I made lots of junk,” he says. Night after night he persevered. Slowly the shapes improved, until he finally made something he had designed – though considering what 3D printers can make now it was a modest triumph. “The first actual part I made was just a small cup shape.” But it was enough. The idea was ready to take to the next level. “We got the patent application in and our patent attorney was all excited. He thought it could be a real breakthrough. A number of the engineers in the company were excited about it too.” Hull was soon back in his boss’s office again, pushing his idea. It was time for the company to commercialise stereolithography, he said. It didn’t fly. Pressing ahead would mean a big investment in time and resources, and his boss decided it wasn’t worth the risk.

“When you’re trying to do something new, very few people see the wisdom of it” It was probably the right decision, albeit for the wrong reasons. What neither of them knew at the time was that somebody had got there before them. Just three weeks earlier, a team at the French General Electric Company led by Alain Le Méhauté had filed a patent for virtually the same process. With no patent and no backing, Hull’s dream was over. He can be philosophical about it now. “The history of technology tells you that when somebody invents something, you can be pretty sure somebody else in the world is close to it too,” Hull says.

3DSYSTEMS

PEOPLE

But coming first is not the same as winning. Le Méhauté’s bosses turned out to be even more risk-averse than his. The General Electric Company abandoned the patent application, seeing no potential in it. Hull’s patent was approved and he decided to go it alone. In 1986 he set up his own company, 3D Systems.“When you’re trying to do something new, very few people see the wisdom of it,” Hull says. “But I’m a pretty positive person. I’d hear all the naysayers and it wouldn’t affect me.” The first people to see the potential were automobile manufacturers, who at the time were lagging badly behind their Japanese rivals. “They were really enthused about what the technology could do for their company, and so we were soon making equipment, training them in how to use it and install it.” Since then, 3D printing has grown and grown. Several methods have been invented, and 3D scanners make it possible to recreate an object exactly. Apps are being developed that will let you scan an item with your smartphone and print a copy. And it’s not just for plastic any more – the technology has been adapted for all kinds of materials, even chocolate. Last year, private exploration company SpaceX used 3D printing to build a rocket engine. Perhaps the most impressive material, though, is human cells. It is now possible to print replacement blood vessels, skin and heart tissue, and 3D-printed organs are undergoing their first clinical trials. It’s a long way from the small cup Hull printed 33 years ago. ■ By Michael Brooks 22 October 2016 | NewScientist | 41

CULTURE

Picking up the pieces

Who Owns the Dead? The science and politics of death at ground zero by Jay D. Aronson, Harvard University Press, £22.95/$29.95

killed at the World Trade Center site. Just 293 bodies were found intact, and 21,900 pieces were recovered from the debris. Despite the most costly forensic investigation in US history ($80 million so far), the remains of 1113 people are unidentified. But that some 60 per cent of victims have been identified illustrates the growing potential of DNA technology for mass identification and the painstaking efforts of those involved. It had been used before for identifying bodies in mass graves, for example after the 1990s genocide in Bosnia and for first world war soldiers, but nothing on the scale or complexity of ground zero. Days after the attack, New York’s mayor, Rudy Giuliani, announced

THE science of mass death is no easy thing to read or write about. It can, however, give us valuable insights into the way politics, technology and a flood of grief can alter our perceptions of how we treat the dead. Who Owns the Dead? does just that, 15 years after the terrorist attacks of 11 September 2001 on the World Trade Center in New York. Its publication also comes amid more controversy stemming from the attacks – as US president “Despite the most costly Barack Obama and Congress forensic investigation in wrangle over a bill that would US history, 1113 victims allow the 9/11 families to sue the remain unidentified” Saudi Arabian government over alleged support of the terrorists. “This book is not for the faint there was little hope of finding of heart,” the author Jay Aronson more survivors, but pledged that warns at the outset. Aronson, the Office of the Chief Medical director of the Center for Human Examiner (OCME) would do Rights Science at Carnegie Mellon “whatever it took to identify the University in Pittsburgh, source of every single human Pennsylvania, gives a harrowing remain recovered from the WTC account. First he looks at the site, no matter how small”. retrieval of body parts and This pledge changed forensic identifying who they belong to. history, upending the “identify all Then he delves into how science victims” approach investigators intersects with politics and the had used. It meant the OCME issue of memorialising the dead. had to keep going until every last One thing is certain: 9/11 was fragment of human material was unprecedented on many levels. paired with a person, or it had An estimated 2753 people were reached the limits of technology. 42 | NewScientist | 22 October 2016

BOSTON GLOBE/GETTY

The 9/11 forensic investigation is casting a long shadow, finds Shaoni Bhattacharya

Human remains have political, cultural and emotional power

Those unidentified remains are now housed below ground in a repository behind the National September 11 Memorial Museum in a climate-controlled environment so that one day improved technology will finally identify them. Aronson’s account describes the recovery efforts amid the pandemonium after the attack. This is sad, horrifying and often gruesome, but it is a story worth hearing as Aronson gives us a sense of the confusing, painful and Herculean effort involved in the most basic identification. We learn how some first responders tried to “reconstruct” bodies, often mingling remains from different people in one body bag. He tells how the blast meant that sometimes parts from one person ended up inside the body cavity of another. And how the different authorities failed to coordinate on the most basic levels, adding to the confusion. The inexperience of the New York Police Department in mass gathering of information and

biological samples made the OCME’s job harder, because the collection of DNA samples was haphazard and didn’t follow protocols. And although initial recovery efforts focused on the 16-acre site of the World Trade Center, for years afterwards, body parts were still being found in vent shafts, roofs and on ledges of neighbouring buildings. It is a hard read – partly because of the devastating subject, but also because of the exhausting toing and froing between committees and subcommittees, the “human remains activist” groups and authorities. The way the dead were to be memorialised was the source of much controversy, echoing the question in the book’s title. There are no easy answers, although the way we treat the dead has all kinds of implications. As Aronson says: “Human remains have political, cultural and emotional power.” Readers can only imagine the prolonged agony of the 9/11 families and empathise with their desire to know what happened. The identification efforts after 9/11 were about separating the US from the perpetrators: emphasis

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Golden oldies We may have old men to thank for our longevity, finds Kate Douglas

on the individual was in marked contrast to the terrorists’ callous disregard for life. As Aronson says: “It was as much a political and moral statement as it was a scientific and legal one.” But it also raises philosophical, psychological and moral questions. As a society, and individually, what does it mean to memorialise the dead? How should we do it? For how long should we wait for technology to give more answers? And at what cost to those grieving? Aronson touches on these, but not deeply enough. At the end, however, he makes a brave point. He notes how the “individualization of victims… has made it more politically palatable for the US... to engage in a seemingly perpetual war”, causing death and injury from Iraq and Afghanistan to Pakistan and Yemen. “One final uncomfortable question we might ask is whether the same kind of unending scientific effort will be taken to identify these victims,” he says. Indeed. ■ Shaoni Bhattacharya is a consultant for New Scientist

WHAT’S the point of old men? We women have had our postmenopausal existence justified, in evolutionary terms, by the grandmother hypothesis. But the same cannot be said for men. The mystery is why they live long past their physical prime, with muscles turning to flab and potency waning. In How Men Age, we have an answer. Biological anthropologist Richard Bribiescas covers some interesting uncharted territory. This is not a mere description of ageing. Instead, by considering male ageing in the light of natural selection, it aims to answer big questions including why men’s Waning testosterone turns older fathers into nurturing “pudgy dads”

lifespans are shorter than women’s, why baldness, prostate disease and erectile dysfunction are so prevalent, and how humans as a species have benefited from men’s tendency to run to fat. From an evolutionary perspective, nothing matters more than sex. And as far as men are concerned, nothing influences sexual power more than testosterone. It increases libido, promotes muscle growth and encourages risk-taking behaviour – all of which help attract a mate. But testosterone peaks in early adulthood, so that men are past their physical prime by the age of 30. It’s tempting to see it as all downhill from there. But with wit and insight, Bribiescas shows convincingly that’s not the case. He points out that testosterone has a dark side – it can increase a man’s metabolic rate and suppress the immune system. In other words, there’s a trade-off, or as Bribiescas puts it: “macho makes you sick”. High levels of the hormone early in life help explain

FERDINANDO SCIANNA/MAGNUM

How Men Age: What evolution reveals about male health and mortality by Richard G. Bribiescas, Princeton University Press, $24.95

why men don’t live as long as women and why they are prone to prostate cancer later on. So waning testosterone can be seen as a positive development. It may make older men less physically competitive against younger ones, but men can produce offspring throughout their lives and, argues Bribiescas, as they age they develop new reproductive strategies to achieve this. For a start, although they may lack raw strength, their experience and guile often make them better providers than their younger counterparts. Bribiescas has done fieldwork with the Ache people of Paraguay, and points to research showing that men’s hunting success peaks in their 40s, long after their testosterone levels peak. What’s more, older men tend to become more nurturing. As testosterone decreases, a man’s girth increases, and the metabolic changes associated with growing adiposity promote care of offspring. Bribiescas calls this the “pudgy dad hypothesis”, and argues that it has implications for the evolution of our species as a whole. Humans live far longer than other primates. For longevity to evolve, natural selection must favour long-lived individuals. Older women cannot reproduce, so they are out of the running. But if, throughout human history, pudgy older men have been fathering children, then they will have passed on genes associated with longevity to both daughters and sons. Old men, therefore, could be the reason we all live so long. It would appear there is some point to them after all. ■ 22October 2016 | NewScientist | 43

CULTURE

Art, but no artist Simon Ings explores the random world of semi-sentient art

IN STANISLAW LEM’S bitterly utopian novel Return from the Stars, astronaut Hal Bregg comes back to Earth from a 10-year mission to find that 127 years have passed during his absence. The world that greets him is very different from the one he remembers. For one thing, its architecture absolutely refuses to stay put. Platforms slide past and around each other, walls and columns spring up out of nowhere, or fall precipitately away: the solid environment has liquefied. He worries – and is right to worry – that he will never find his feet in this new place. The Paris-based artist Philippe Parreno is kinder than Lem. Visitors to his vast installation at London’s Tate Modern, Anywhen, get a carpet to lie on while the vast Turbine Hall shimmies and pulses around them. Let there be no doubt here: Parreno’s awful grey machine is triumphally futuristic, an interior so smart it has outgrown any need for occupants. Anywhen is thunderous, sulphurous, awful in its full archaic sense. Visitors find themselves in a sort of aquarium, in which sound and light obey a claustrophobic new physics. Speakers descend from and ascend to the ceiling, relaying captured outside noise from nearby teenagers, a fragment of song, a passing aeroplane. Banks of lights flash. In a sudden hiatus, bits of colour drop down from somewhere on to An exhibition shaping itself as fish float around and screens descend 44 | NewScientist | 22 October 2016

a giant mobile screen and float off. and movement are variables in Some are murky projections, but a biocomputed algorithm that there are solid objects, too, in the will enrich the installation’s shape inflatable fish. These seem behaviour during its six-month a lot more at home in this shifting run. It still remains to be seen space than we do. Huge, white, whether those initial conditions architectonic panels reconfigure are rich and complex enough the dimensions of the gallery, to generate a significant moving up and down with more creative work. than random malevolence. Is Right now, as you lie there, this malevolence an illusion? hands scrabbling for purchase Of course, but it’s an utterly “The Turbine Hall has been convincing one – so much so invested with a terrible, that one wonders what the alien intentionality. artist means by it. Is this another illusion?” Alas, Parreno is not here to answer. He has, it seems, ceded control of his installation on the thin carpet, it seems to a colony of bacteria, fed and as if the Turbine Hall has watered in a small lab visible in an been invested with a terrible, out-of-the-way corner. Changes in alien intentionality. Is this the colony’s temperature, growth another illusion? It must be.

KIRSTY WIGGLESWORTH AP/PRESS ASSOCIATION IMAGES

Anywhen by Philippe Parreno, Turbine Hall, Tate Modern, London, until 2 April 2017

And yet, how can we be sure? The 17th-century German philosopher Gottfried Leibniz once came up with a thrilling but flawed argument for the existence of God. In one of his best-known works, Monadology, Leibniz invites readers to imagine that they are visiting “a machine whose structure makes it think, sense, and have perceptions”. There would be plenty to see: innumerable cogs, wheels, belts and gears. But that, says Leibniz, is precisely the problem – “we will find only parts that push one another, and we will never find anything to explain a perception”. The same issue arises when we explore the brain: no amount of mapping, no amount of analogy, brings us any closer to the subjective “is-ness” of conscious experience. Leibniz used his thinking mill to assert that the world is more than material, and that thinking must occur on another (divine) plane of existence. He was a glass-half-full sort of thinker, whose rambunctious belief in the essential goodness of the universe – all is for the best in the “best of all possible worlds” – drove an exasperated Voltaire to pen his savage satire Candide. Anywhen is Leibniz’s mill made flesh in glass, wire and panelling. Lying on the grey Turbine Hall carpet, I couldn’t help but wonder with Voltaire how on earth Leibniz took comfort from his own story. Something is using the Turbine Hall to think with, but we can bet the farm it is not God. Imagine wandering into the toils of some vast, cool and unsympathetic intellect. Imagine the Martian has landed… ■

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LETTERS EDITOR’S PICK

Compare mystery and a known fake From Ian Simmons You report on Gordon Rugg’s work, which concluded that the Voynich manuscript is gibberish, while still following the structure of a true language (1 October, p 12). I recently compared the Voynich text and the similarly baffling Rohonc Codex from Hungary with the Codex Seraphinianus, published in 1981 by the artist Luigi Serafini. This couples cryptic text with illustrations at least as strange as anything in the Voynich manuscript. Like the Voynich and Rohonc texts, much effort has been put into deciphering the Codex, again with little success apart from confirming that it conforms to the structure of a true language. The advantage with this volume is that the creator is alive. Although he has refused to enlighten anyone on the detailed meaning, he has dropped a hint about the volume’s language. At a lecture in Oxford in 2009, he explained that he wanted the book to create the impression a small child, unable to read, has on encountering a book for the first time. To that end it is written in an asemic script – one that has the form and structure of a real text, but no meaningful content – making it akin to a written form of glossolalia or “speaking in tongues”. I suspect both the Voynich manuscript and the Rohonc Codex are also asemic, and that any attempts at decoding them will also end in failure. Monkseaton, Tyne and Wear, UK 52 | NewScientist | 22 October 2016

Signal failure and crossword success From Phil Pope Simon Makin reports that people can assess the competence of teachers or politicians within seconds, merely on the basis of their appearance, body language and social signals (1 October, p 30). The evidence is that these first impressions correlate to students’ evaluations of teachers at the end of courses and to politicians’ success in elections. More pessimistically, I suggest that large numbers of people are unable to assess the competence of teachers or politicians, no matter how much time they have. They continue to base their judgement on their superficial first impression. Thus incompetents are praised and elected to office. This appears to correlate with observations. Bristol, UK From Brian Horton It is apparently possible to accurately rate another person’s character after seeing their picture for 0.1 seconds. But we don’t know what particular features make people appear trustworthy or competent. We can instantly tell heroes from villains in a film, unless the director deliberately conceals this for plot purposes. So can movie directors shed light on what characteristics are critical? If they won’t tell us, let an artificial intelligence watch thousands of films and work it out. West Launceston, Tasmania, Australia From Peter Robbins It’s rather humbling to realise that most of our mental functions are carried out unconsciously. I suspect that there isn’t only a distinction between our conscious and unconscious mind, but also between various levels of our unconscious. A name coming to mind some

time after I’ve been struggling to remember it is a common experience. More interestingly, the answer to a crossword puzzle clue often pops up long after I have ceased thinking about it. The unconscious me that drives my car is impressive, but quite different to my inbuilt crossword clue solver. London, UK From Roger James You say that in forming habits “practice makes perfect”. I have been telling trainee trainers for more than 30 years that in fact guidance, correction and coaching make perfect (or at least correct). Practice (repetition) makes permanent. If what one practises is wrong, wrong will be made permanent. Crigglestone, West Yorkshire, UK

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others modelling how networks of genes evolve to the “edge of chaos”. The emergence of similar forms by seemingly separate evolutionary pathways may be the result of “strange attractors” in the evolutionary space. Perhaps Richard Dawkins’s greatest contribution wasn’t the popularisation of the “selfish gene” meme, but the concept of the “meme” itself as a unit of cultural inheritance. Still, the meme has been slippery to define. Blockley, Gloucestershire, UK From Michael Guppy The bird’s nest depicted with this article is even more interesting from an evolutionary point of view than you may have realised. The reed warbler pictured is feeding a cuckoo. Moruya, New South Wales, Australia

Evolutionary forces Chill out before may evolve too replacing a fridge From Lois Pryce Kevin Laland discusses how concepts of evolution could evolve (24 September, p 41). Is it not likely that evolutionary forces are themselves subject to evolutionary forces? After all, anything that gives living organisms the edge in survival will be prioritised. That would include any improvements on the purely “blind chance” method of generating adaptive variations. Bristol, UK From Matt Black The description of evolution evolving was a much needed summary for many who have long viewed the “selfish gene” theory as too narrow. But a word missing from the article was “feedback”. The realisation that information flows from organism to environment and the other way, so that each modifies the other, implies a feedback loop. I am now inspired to look at the work of Stuart Kauffman and

From David Empson Having recently replaced a thermostat in my old freezer, I was interested in Michael Le Page’s suggestion that this wasn’t a green thing to do, as old appliances use more power and become inefficient with age (1 October, p 23). But he referenced figures from the US market, which may not be relevant to the more energy-conscious Europe. I have measured the energy usage rate of my 10-year-old standard German fridge at 85 kilowatt-hours per year, and of my 19-year-old Swedish freezer at 321 kWh per year. They appear to be 27 per cent and 7 per cent better than their as-new specifications, not worse. Of course this may be due to my house being cooler than that assumes. But neither figure is anywhere near the 1000 kWh per year given in the study referenced. Perhaps people should use a cheap energy meter before deciding on whether to renew an

“Our surprise at their ‘theory of mind’ shows how limited ours is” Emma Olver greets proof of chimps, bonobos and orangutans grasping how others view the world (15 October, p 7)

appliance, rather than just looking at its age. Bristol, UK

Odds on climate change accepted From Jules May Andrew Collins asks whether climate-change sceptics would accept his $1000 bet that the global mean temperature will exceed the 2015 record within 10 years (Letters, 17 September). He is conflating two different ideas. One can easily accept that the world is heating up – thus, on the face of it, making the offer a bad one – while still asserting that the change is due to sunspots, volcanoes or any other nonhuman mechanism. Surely those he needs to convince are deniers of anthropogenic climate change? There is also a flaw to his logic. Had he made the offer last year, with regard to 2014’s record high, he would have stood a very good chance of making his point. But the 2015 high of 0.87 °C over TOM GAULD

baseline is clearly an outlier. Looking at it statistically, I would say that the global temperature is, in financial language, significantly overbought, with falling momentum. Based on current trends, I predict (with better than 50 per cent confidence) that the next time the 2015 record will be beaten will be around 2033 – almost 20 years away – and even then by another outlier. It won’t be until around 2060 that such temperatures become normal. I’ll take his bet, if he’s still minded to stand by it. Montrose, Angus, UK Andrew Collins writes: ■ Of course I will! I don’t fear

regression to the mean. I fear departures from the historical mean. Let’s hope I lose.

Carbon black for soil improvement From Nik Kelly Jon Cartwright describes a reaction that produces hydrogen

from methane – and mountains of carbon black (8 October, p 28). Could we pelletise that to the consistency of “biochar” for soil improvement? The build-up of low-lying coastal fields could be an extra benefit. Liverpool, UK

These memories will not fado away From Luciana Cardoso I very much enjoyed your article about nostalgia (24 September, p 36). It touched on my research into the Portuguese emotion saudade – which could be roughly described as a mix of longing, melancholy and nostalgia. It arose during the maritime conquests of the 16th century. When the sailors travelled to strange lands, the feeling was present in the memory of those who sailed away and also of those who stayed behind waiting for their return. It eventually came to be seen as a characteristic of the Portuguese people. Musical genres such as fado, morna and

choro have saudade as one of their main themes. Windsor, Berkshire, UK

Bacterial obscurity is still not secure From Andrew Mulholland You report on increasing the security of spores carrying data by hiding them among other spores to make it almost impossible for a snooper to identify them (24 September, p 25). This is colloquially known as “security through obscurity”. It deters only casual crackers. An adversary specifically targeting a user will make sure that they know which spores to look for. St Peter Port, Guernsey

Species change to save the planet From Perry Bebbington When proposing synthetic biology to fix our planet, Ricard Solé gives an analogy of removing large, predatory fish from a lake to reverse algal blooms (1 October, p 36). I immediately thought “yes, that would work: remove the large, predatory simians currently trashing the planet and the climate change problem will end”. Kimberley, Nottinghamshire, UK

For the record ■ Marcus Tullius Cicero was a Roman lawyer, senator and philosopher (8 October, p 32)

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flame on contact with water,” says Barry, “so this mineral will certainly sizzle in the mouth.”

PAUL MCDEVITT

COMPUTER scientist Robert Garner is left straining over the maths he finds printed on his jumbo bag of kitty litter. The “World’s Best Cat Litter” claims to provide enough for two cats for 60 days, and four cats for 30 days. “Fair enough,” says Robert. “The formula appears to be 120 days divided by the number of cats.” But those with three cats are told they can expect each sack to last 45 days. “Where do the extra five days come from?” he muses.

THE cosmos calls on us once again to usher the golden tufts of TV presenter, positivity ambassador and electrosmog campaigner Noel Edmonds onto our page. Having previously extolled the virtues of a supposedly cancer-busting electronic yoga mat (25 June), the Deal or No Deal host has a new service for those who have everything: a radio station for animals. Positively Pets will soon join Edmonds’s “genre-casting” smorgasbord of niche internet radio stations built around themes such as slimming, babies and snow – all presumably aimed at people who haven’t heard of Spotify playlists. As well as curating an animalfriendly channel to keep your pets entertained while you’re away from home, the House Party star will phone your pet and read out a message of support. Edmonds previously claimed to be part of a consortium that planned to purchase the BBC: is this a window into the new audiences he would pursue on becoming director-general?

BARRY CASH writes to note a deficiency of fruitloopery in our column of late, and offers to remedy that with an enclosed pamphlet for “Sizzling Minerals” by Simply Naturals. The flyer is packed with information; unfortunately for readers, much of it is simply nuts. For instance, we are told that dinosaurs “were able to grow to enormous sizes because the minerals and nutrients were available in the soil”. Make soils great again! Testimonials are included from happy customers, who find themselves relieved of the effects of age, diabetes, rheumatism, deformity, lack of fitness, psoriasis, combat fatigue, multiple sclerosis and asthma. Most crucially, Anthony Twohill reports that after being fed Sizzling Minerals, his two racehorses are now storming to victory, adding that “blood proves negative for any banned substances”. Good to know for any customers planning to enter the Grand National. The flyer also warns against the dangers of sodium chloride and its link with high blood pressure. Instead it recommends “good” sodium. “Now, as I remember, pure sodium bursts into

Martin Necas sends a message from a hospital clinic attendance database: “Sorry, cannot check whether this patient is frozen.” And if they were? 56 | NewScientist | 22 October 2016

WE JUST can’t help ourselves. Peter Rodriguez spots a headline in the New Zealand Herald: “Former navy boss takes helm at RSA.” His name: Jack Steer.

OH, THE perils of Pokémon Go: the journal Oxford Medical Case Reports details two accidents caused by players chasing after digital creatures in the hit augmented-reality game. In one, a female driver hit a utility pole after swerving to avoid a pedestrian who wandered into the road while immersed in the game. Perhaps more frighteningly, the second involved a 19-year-old man who attempted to swipe his phone to capture a Pokémon – while driving a pickup truck at 65 kilometres per hour. He lost control of the vehicle, hospitalising himself and ejecting three friends from the bed as it rolled over. Players are advised to pocket their phones when on or near roads. It’s super-effective! RECENTLY Feedback discussed the ongoing battle over the shale gas industry in the UK, with those on all sides throwing accusations they could not substantiate (8 October). In the US, they do things differently. Oklahoma governor Mary Fallin designated 13 October as Oilfield Prayer Day, during which citizens can eat breakfast together and beseech higher powers to rescue the state

from an economic crisis precipitated by crashing oil prices. US president Harry Truman famously kept a sign on his desk reminding him “The buck stops here.” Senator Fallin appears to have delegated to a yet higher power.

OUR colleagues in the preceding pages labour to present climate models in a form easily digestible by readers. Jonathon Keats has gone one better, creating a suite of sweets to embody climate change. “Using a breakthrough scientific technique known as data gastronification,” says Keats, “information is sensed by your alimentary canal and processed by your enteric nervous system. Rather than merely glancing at the complex relationship between fossil fuels, the atmosphere and the planet, you feel it in your gut.” Keats, an “experimental philosopher”, has rendered the warming seas and melting permafrost in ice cream, “the perfect food for gastronifying climate scenarios”, and a product

for which demand can only grow as we swelter in unseasonal heat. What does climate change taste like though? Rich and indulgent, but with a bitter aftertaste, perhaps. Visitors to the STATE Festival for science, art and society in Berlin, Germany, next month will be able to find out. Given that we’re so often told big data will eat the planet, here’s your chance to bite back.

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THE LAST WORD

■ Far from being afraid of us, there are plenty of creatures – mainly insects – that take the opportunity to drink our blood. Mosquitoes, fleas, ticks and leeches all do this, and we are often unaware it is happening. Some unfortunate people even play host to the parasitic larvae of the human botfly through wounds. Sometimes butterflies land on us to drink our sweat for the sodium it contains. A creature normally avoids getting closer to a potential predator than the shortest head start it needs to escape: its flight distance. This means that quicker creatures can often get closer to us. When a housefly lands on someone, it may start preening itself, giving the impression of being relaxed. Yet when we try to swat it, the quick-witted fly sees our hand approaching and easily evades us. The same logic applies with larger animals. For example, the flight distance for seals differs depending on whether they are underwater or lounging on a beach. In the ocean, they happily tug at the fins of scuba divers, knowing that they can outswim humans with consummate ease.

around, possibly looking for On land, they head for the surf at food. When they find none, the first hint of danger. they crawl up to the highest There are many examples point and fly away. of animals on the Galapagos Mantids are even more Islands and elsewhere that allow people to get close because we are unwilling than ladybirds to take flight. They rely on their peculiar unfamiliar and not perceived as a threat. Sadly, it was this type of behaviour that led to the demise “Ladybirds rely on warning colours, together with of the dodo on Mauritius. their nasty taste and Mike Follows smell, to deter predators” Sutton Coldfield, West Midlands, UK way of moving, or indeed not moving, to avoid predation. One ■ Sometimes it is a mistake on your hand will clearly show to anthropomorphise insects. itself to be uncomfortable, and It is unlikely that they have any will slowly try to extricate itself. concept of fear. Each behaves The truth is that different according to how it has evolved insects respond differently. and in keeping with its particular Terence Hollingworth attributes. To them, a hand Blagnac, France holds no interest, unless they are attracted to its salty secretions or to any aromatic residues from whatever it has been in Sticky ice contact with. I don’t make a habit of handling I was watching the bobsleigh event at the Winter Olympics and it was foggy. bees, yet I would suggest they The commentator said that the extra have had no past experience that humidity caused by the fog would has caused them to avoid hands. “stick to the track” and slow the I once caught one by accident as competitors down. How? I would I walked past a lavender bush assume extra moisture in the air swinging my arms. It didn’t would make the track more slippery sting me, presumably because and thus faster. it didn’t perceive a threat. Ladybirds cannot readily take ■ The essence of success in a off, and they rely on warning bobsleigh competition is speed. colours, together with their Ice is laid down on the concrete nasty taste and smell, to defend course in millimetre layers over themselves from predators. They are therefore not in any particular several days to a thickness of hurry to fly away. Flying also takes around 5 centimetres. The concrete is networked with far more energy than walking. I have had starving ladybirds nibble plumbing, through which at my hand, but usually they stroll ammonia refrigerant flows,

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

Fly away home? Why are some small creatures unafraid of humans? If a bee, ladybird or praying mantis settles on my hand, they seem reluctant to leave. But I have yet to experience lingering contact with a butterfly, small reptile or bird.

keeping the ice at about -6 °C. The ice meister, who oversees the track, uses sensors in and around it to keep informed about the conditions, so all aspects of the course are controlled and optimised for speed. Nature is harder to manage, and humidity can pose a problem. If the temperature drops towards the dew point, moisture condenses from the air and a crystalline frost forms on the ice. This hoar frost acts as a brake under the sleighs’ runners. Before racing, the track is shaved and sprayed to ensure no frost or bumps remain to slow down the sleighs. You can experience the unlikely friction caused by frost if you walk on an icy path in the evening, then again the next morning when there is a fresh covering of hoar frost. You will find that your grip is greatly improved. David Muir Edinburgh, UK

This week’s question DRIVERLESS DYNAMICS

In the UK’s Lake District, tourists tend to drive slowly, leading to congestion on relatively long stretches of road. Would driverless cars make the flow dynamics better or worse? If any of the remaining drivers were scared of going close to the speed limit, would this negate the use of the driverless element? Freyja Burrill Kendal, Cumbria, UK

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