New Scientist - 28th February 2009 Malestrom

EDITORIAL

For the planet it’s geoengineer or bust We’re clearly failing to reduce emissions so it may be time to adjust the Earth’s thermostat DESPITE the numerous warnings about extreme weather, rising sea levels and mass extinctions, one message messa ge seems to have got lost in the debate about the impact impa ct of climate change. A warmer world won’t just be inconvenient. Huge swathes of it, including most of Europe, the US and Australia as well as all of Africa and China will actually be uninhabitable – too hot, dry or stormy to sustain a human population. This is no mirage. It could materialise if the world warms by an average of just 4 °C, which some models predict could happen as soon as 2050. 2050. This is the world our children and grandchildren are ar e going to have to live in. So what are we going to do about it? One option is to start planning to move the at-risk human population to parts of  the world where it will still st ill be cool and wet (see page 28). It might seem like a drastic move, but this thought experiment is not about scaremongering. Every scenario is extrapolated from predictions of the latest climate models, and some say that 4 °C may actually turn out to be a conservative conser vative estimate. Clearly this glacier-free, desertified world – with its human population packed into

high-rise cities closer to the poles – would be a last resort. Aside from anything else, it is far from being the most practical option: any attempt at mass migration is likely to fuel wars, political power struggles and infighting. So what are the alternatives? The most obvious answer is to radically reduce carbon dioxide levels now, by fast-tracking green technologies and urgently implementing energy-efficient measures. But the changes aren’t coming nearly quickly enough and global emissions are still rising. As a result, many scientists are now turning to “Earth’s plan B” (see page 8). Plan B involves making sure we have large-

“Perhaps geoengineering projects can avert the more horrifying consequences of climate change” scale geoengineering technologies ready and waiting to either suck CO 2 out of the atmosphere or deflect the t he sun’s heat. Most climate scientists were once firmly against fiddling with the Earth’s thermostat, fearing that it may make a bad situation even worse, or provide politicians with an excuse to sit on their hands and do nothing. Now they reluctantly acknowledge the sad truth that we haven’t managed to reorder the world fast enough to reduce CO2 emissions and that perhaps, given enough funding, research and political muscle, we can indeed design, test and regulate geoengineering projects in time to avert the more horrifying consequences of climate change. Whatever we do, now is the time to act. The alternative is to plan for a hothouse hothous e world that none of us would recognise as home. ■

Forensic science: guilty as charged SINCE it began in 1992, the Innocence Proj ect has deployed DNA evidence to exonerate 232 people previously convicted in American courts. Faulty interpretation of forensic evidence had contributed to around half  the wrongful convictions. This failure of forensic science to protect the innocent is underlined in a report from the US National Academy of Sciences (see page 6). A core concern was the unreliability of  traditional techniques compared with DNA methods. These older techniques, which are still relevant, need stronger scientific backing – yet it is DNA that gets most of the research resear ch funding. Let’s hope the report will change that. For justice to prevail, we need to put forensic science onto the firmest possible footing and subject it to the rigorous testing it deserves. ■

Volte-Facebook IN THE wake of a recent brouhaha, Facebook has backtracked on changes that potentially gave the social networking site indefinite rights to its users’ data – even from closed accounts (see page 12). But a closer look at its terms and conditions suggests Facebook has lost nothing but face. face. Users, perhaps p erhaps unknowingly, have always granted Facebook a licence to peddle their information to anyone willing to pay. The controversy is a timely reminder that social networks want more than your company, and that it pays to read the small print. ■

What’s hot on NewScientist.com SPACE Second man on moon critical of NASA The space agency’s performance since the Apollo programme has been “lacklustre” and NASA needs “serious reform or significant organisational overhaul”, says Apollo legend Buzz Aldrin

if they’ve been somewhere before, just like us FORENSICS Inside the skull of a suicide By combining surface scans of the body with CT and MRI scans, scans, it is possible to work out what happened to a person without cutting them open

TECH Mirrors: the next generation Explore images of mirrors that can reflect text without reversing it, capture a 360-degree view without distortion or help robots climb stairs, all thanks to computer-aided design

PSYCHOLOGYScared PSYCHOLOGY Scared of heights? Find out why People who shudder atop skyscrapers or whose knees buckle crossing bridges have trouble perceiving the vertical dimension

ROBOTICS ‘Déjà vu robots’ don’t get lost Robots that make maps as they go need to detect

Find these articles and more at www.newscientist.com/article/dn16651

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28 February 2009 | NewScientist | 3

UPFRONT

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Cut-and-dried fire hazard WE HAVE turned the world’s third-largest rainforest region into a tinderbox that the warming world will help ignite. So concludes a new study of forest fires in Sumatra and Borneo in Indonesia. Robert Field, Field, an atmospheric physicist at the University of Toronto in Canada, and his colleagues examined the fire history of forests in Indonesia by analysing five decades of visibility records at nearby airports. Droughts – usually during El Niño seasons in the Pacific – have triggered huge fires in Indonesia seven times since 1960. But Field’s team found that until 1980 the fires were limited to Sumatra, where human activity and deforestation were greatest. Borneo’s forests did not burn. However, after humans began

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large-scale encroachment encroachment on Borneo in the 1980s – with deforestation rising above 2 per cent per year – its forests too suffered massive fires during periods of drought. drought. Field says clearing vegetation for farming reduces the moisture in the ecosystems, leaving them vulnerable to wildfires (Nature Geoscience , DOI: 10.1038/ngeo443 10.1038/ngeo443). ). The biggest source of greenhouse gases released by forest fires in southeast Asia is not the trees, says Field. Instead, it is the burning of peat in the deep swamps on which many forests grow. So Field’s findings add to concern over Indonesia now ending a two-year moratorium on allowing oil palm and tree crops to be planted on peatlands. Such a move will lead to more fires, Field warns.

–Borneo burning– burning–

Flu’s Achilles’ heel THE flu virus is a slippery customer, expert at escaping attack by our immune system. But there is a chink in its defences that could lead to a universal flu vaccine. We can get flu repeatedly because the virus evolves: its surface proteins change, so the antibodies generated by one bout are not effective a second time. For the same reason, the vaccine for one year’s strain won’t work in later years. Now Wayne Marasco at Harvard University and his team may have found a way round this. The flu virus’s main surface protein, haemagglutinin, is lollipop-shaped, and existing vaccines stimulate the production of antibodies that bind to its big

“When injected into people, the antibodies lasted long enough to offer protection in a pandemic” round head – which changes every year. But in a library of human antibodies, Marasco’s team found a few that target proteins on the “stalk”. These proteins barely 4 | NewScientist | 28 February 2009

change between flu strains, which suggests they don’t evolve quickly ( Nature  Nature Structural and Molecular   Biology, DOI: 10.1038/nsmb.1566). Marasco’s team suspected that the prominent head of the lollipop normally attracts the attention of the immune system away from the stalk. If the immune system could be persuaded to target these unchanging proteins, they reasoned, it might be possible to provide protection year after year. His team produced antibodies to these stalk proteins in bulk, and injected them into mice before and after they were infected with a range of flu viruses, including H5N1 bird flu, pandemic H1N1, and ordinary flu. The antibodies protected or cured the animals in each case. In cell cultures, cultures, the viruses did not evolve to escape the stalk antibodies, so a vaccine based on them should, in theory, t heory, work for longer than a year. In a pandemic, the antibodies alone might offer useful protection. They last more than three weeks when injected into people, which could keep them alive long enough to make their own antibodies.

Canada. Kaede Ota and her colleagues at the Hospital for Sick GONORRHOEA is becoming Children in Toronto found that dangerously antibiotic-resistant. quinolone-resistant infections in The sexually transmitted Ontario soared from 4 per cent of  disease,, which can lead to disease infections in 2002 to 28 per cent infertility in men and women, in 2006 (Canadian Medical is treatable with antibiotics. But  Association Journal, DOI: 10.1503/ following recent resistance to the cmaj.080222). The team blames quinolone family of antibiotics the surge on a mixture of unsafe in the US, UK and Australia, sex and people not completing authorities in these countries now prescribed courses of antibiotics. recommend cephalosporins, the The fear is that strains resistant only option besides quinolones. to all antibiotics will appear. The In the latest setback, quinolone first cephalosporin-resistant resistance seems to have spread to strains appeared in 2008 in Japan.

The clap is back

Comet Lulin drops by for a visit THE Earth had company this week, when comet Lulin passed within 61 million kilometres of us, almost as close as Mars. It reached peak brightness on 24 February, when it could be seen passing close to Saturn, but should remain visible in the sky until mid-March. The close pass gives astronomers their first chance to analyse the comet’s constituents, says Jenny Carter from the University of Leicester, UK. Images of Lulin taken

by NASA’s Swift telescope (see image, right) should help determine the comet’s exact chemical composition. The blue colour shows the presence of hydroxyl ions – formed when water breaks down – and the red is where the solar wind is interact interacting ing with material from the comet. Gary Kronk, an amateur astronomer from St Jacob, Illinois, recommends using a small pair of binoculars to look at the comet, which has an unusual double tail.

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60 SECONDS

Tax space space cowboys SPACE junk has so far evaded even the most imaginative of tax collectors. But fining offenders could slash orbital debris. The hazard posed by debris was shown on 10 February, F ebruary, when a defunct Russian satellite destroyed

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‘Alps’ under Antarctica Antarctic a

“Quote to go in here over four lines range left like this Quote to go in her like this this xxxxx” xxxxx ”

“Space tidiness could be improved by fining those that do not dispose of satellites safely”

The existence of a mountain range the size of the Alps, 4 kilometres below the Antarctic ice sheet, was confirmed this week. Aircraft carrying ice-penetrating radar established that the Gamburtsev mountains are rugged, with deep valleys and steep peaks. This suggests that they formed relatively quickly as the vast East Antarctic ice sheet ploughed over them.

Shoot for the moon

a US communications satellite. satellite. Such collisions can be avoided if nations dispose of satellites safely, either by parking them in “graveyard” orbits or burning Rosy outlook them up in Earth’s atmosphere. But take-up of these methods is FLUORESCENT pink strips are far from universal. helping to save albatrosses and petrels from extinction. An international framework to fine countries that fail to do Baited hooks on the long this would encourage tidier fishing lines used to catch tuna and swordfish snag and kill some habits, suggest Andrew Bradley and Lawrence Wein of Stanford 100,000 albatrosses and petrels University in California ( Advances year. In a bid to  Advances worldwide a year. reduce this toll, the UK charity in Space Research, DOI: 10.1016/ j.asr.2009.02.006). j.asr.2009.02.006 ). Any money Albatross Task Force tied pink collected could go into a fund to strips to the fishing lines used by compensate owners of satellites the long-line fishing fleets roaming damaged by debris, or be used to South African waters throughout research cheaper ways to de-orbit satellites, they say. “The pink strips reduced petrel and albatross deaths “On the surface, it’s a very appealing idea, but the t he devil’s from long-line fishing by in working out the details,” says 85 per cent” Henry Hertzfeld of George Washington University in 2008. The idea was for the strips Washington DC. to frighten off the birds, stopping them from becoming entangled and drowning. They found that only 153 petrels and albatrosses were killed by the long-line fishing fleets that year – an 85 per cent reduction on 2007. 2007. “They form a visible deterrent and a no-go zone close to the bait and fishing gear as it’s reeled out,” says Graham Madge of the Royal Society for the Protection of Birds, a UK charity. The strips are only needed for 150 metres of the line before it is submerged and the bait sinks to depths of up to 60 metres, beyond b eyond –What’s in a comet?– comet?– the birds’ reach.     O     T     O     H     P     P     A

–Albatrosses avoid pink– pink–

The task force wants countries to make bird conservation a legal obligation. Last year, a new South African law stated that vessels killing 25 or more birds would lose their licence. The method should help fishing fleets comply with the law. The strips are reusable and cheap, costing about $200 per ship, and don’t deplete the haul, says Madge.

Carbon satellite lost IT WAS designed to solve a longstanding mystery about missing carbon dioxide, but as New NASA ’s Scientist went to press, NASA’s new climate satellite seemed to have gone AWOL itself . The Orbiting Carbon Observatory (OCO) was designed to monitor exactly where and when CO 2 is being emitted and absorbed. Of  the total CO2 emitted by humans since the Industrial Revolution, roughly a third is known to have ended up in the atmosphere and a third in the oceans. The rest is is missing – probably in carbon sinks on land. The OCO was supposed to have shown where. The mission failed, says NASA. The rocket lifted off on 24 February from a California base, but later data suggested that the fairing – intended to reduce drag – failed to separate, meaning the satellite did not reach orbit. NASA suspects it fell into the ocean near Antarctica.

India has announced plans to send two astronauts into space by 2015. The low-orbit mission will cost £1.7 billion and would put India alongside the US, Russia and China as the only countries to have sent a human into space. Indian space officials say that their ultimate goal is to go further than the moon, which will require crewed as well as robotic missions.

China blames the west A third of China’s carbon emissions come from making goods for export, especially to the US and UK. Such emissions are not its responsibility responsibility,, says China’s government, which is under pressure to curb greenhouse gas emissions.

Fat, cigs and early death Being obese at 18 is as dangerous as smoking. Each doubles the risk of an early grave, according to a study in the BMJ of of 45,000 Swedish men (DOI: 10.1136/bmj.b496). Obese 18-year-olds who also smoked heavily are five times as likely to die early as their non-smoking peers of normal weight.

Cheaper sequences? A tiny pore that detects e lectrical changes as a strand of DNA passes through it could provide cheaper DNA sequencing as it avoids using imaging tools. Pores made by UK firm Oxford Nanopore Technologies can distinguish between the four DNA bases, and bases with chemical “caps” (Nature Nanotechnology , DOI:10.1038/NNANO.2009.12).

28 February 2009 | NewScientist | 5

THIS WEEK

Forensic evidence

goes on trial When a suspect’s fate rests on evidence from the scene of a crime we need to know how reliable it is Linda Geddes, Denver, Colorado

LAST month, Steven Barnes was exonerated of the rape and murder of a 16-year-old New York schoolgirl in 1985. Barnes had been convicted of these crimes on the basis of forensic evidence, including testimony that soil on his truck tyres matched that at the crime scene. An imprint on the outside of his truck also supposedly matched the pattern of the jeans the victim was wearing when she was killed. But this year, tests showed that DNA samples from the murdered girl’s body and clothing did not match Barnes’s, and he was freed after spending 20 years in jail. The US National Academy of 

“The report helps show why so many innocent people get convicted in the US based on junk science” Sciences fears that miscarriages of justice like Barnes’s original conviction are all too common. In a highly critical report on the state of forensic science in the US, published last week, it questions the reliability of using techniques like hair or fingerprint analysis to link a person to a crime. The report was welcomed by delegates at a meeting of the American Academy of Forensic Sciences in Denver, Colorado, last week. “I think it’s long overdue,” says Michael Baden, chief forensic pathologist for the New York state police. “It brings criticisms of  why so many innocent people get convicted in this country based on junk science.” It is also the first fir st 6 | NewScientist | 28 February 2009

independent review to lay out guidelines on how forensic evidence should be collected and analysed, and is likely l ikely to have global ramifications, says lawyer and forensic scientist Judith Fordham of Murdoch University in Perth, Western Australia. But while forensic scientists agree that their discipline is due an overhaul, and indeed several are trying to make traditional techniques more robust (see below right), some say the report’s rep ort’s recommendations do not go far enough. “A “A lot of o f them are naive,” says Peter De Forest of John Jay College of Criminal Justice at the City University of New York. At the heart of the problem is the absence of scientists at the front line of investigations, De Forest says, yet the report fails to address this. It is scientists who should determine which tests are most appropriate for a particular crime scene, he says. At present it is left to police officers and prosecutors to decide. Also at fault is the system that allows prosecutors to bring expert witnesses into court to interpret evidence that they have had no hand in collecting. “In some of  the wrongful conviction cases it wasn’t the scientist who got it wrong, it was the prosecution that misinterpreted it,” it ,” says De Forest. Other forensic scientists are worried that the report’s heavy criticism of the way traditional techniques are used will lead to them being wrongly dismissed in favour of DNA evidence. Many traditional methods “are getting short shrift” shri ft”,, says Brian Gestring of Cedar Crest College

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BLOODSTAINS

HAIR

Analysts claim they can identify how a bloodstain was created – by dragging a dead body, say – just by looking at it. But how reliable is this technique? Brian Gestring of Cedar Crest College in Allentown, Pennsylvania, Pennsylvania, asked 92 professional analysts and 65 non-experts to pinpoint how 10 different blood patterns were made. The experts got it right 97 per cent of the time, and lay people 21 per cent. The study is the first step towards being able to quantify an error rate that jurors could be presented with when hearing evidence in court. Now Gestring wants to put experts’ abilities to the test in mock crime scenes. These experiments are not making Gestring Gest ring popular. “Some examiners were really angry with me,” he says.

Human hair is often shed at crime scenes. While DNA typing can help trace it to an individual, this is timeconsuming and expensive. Instead, analysts scrutinise hairs under the microscope, looking for features that establish a visual match between two samples.  Julie Barrett and her colleagues at Indiana University in Indianapolis have investigated how dyes affect the way hair absorbs different ultraviolet wavelengths. Her method could add weight to a visual match between two hair samples. “Because there’s a tangible spectrum, we can put some numbers to it,” she says. But this technique could not be used in isolation, as hair from the same person can absorb dye to different degrees, complicating the analysis.

In this section ■ Are we ready to tweak Earth’s thermostat, page 8 ■ Ovaries get more youthful with age, page 11 ■ Anthrax attack evidence revealed, page 13

FINGERPRINTS Analysing the whorls and eddies of our fingerprints is the grandaddy of forensic techniques, but it has come under heavy criticism in recent years. Fingerprint analysts have “been the authors of their own misfortune by saying that there’s no error rate”, says Judith Fordham of Murdoch University in Perth, Western Australia. As with bloodstain analysis, no one knows how often analysts make mistakes. “The question that needs to be asked is not whether or not fingerprints are unique, but whether or not the examiner can tell them apart,” says Fordham. She would like to see blind testing of analysts to assess error rates, using prints from real crime scenes. “They’re just going to have to come up with the numbers and the stats.”

in Allentown, Pennsylvania, who amount of biological evidence points out that such techniques has been left behind. Yet even can still play an important role DNA evidence may not be in investigations – provided they unequivocal. It too is open to are interpreted properly and not interpretation, and there have been relied on uncritically. cases where it has gone wrong. “If I went to a crime scene and Both the report and its critics collected a blood sample from agree on one point: the reliability under a bleeding victim, I don’t of many forensic techniques know that I’d need $100,000 of  urgently needs to be quantified. quantified. DNA testing to tell me it’s the “A lot of the techniques used victim’s blood,” Gestring says. “What I would need to do is look “The reliability of many at the pattern of the blood to see long-standing forensic if it was consistent with it being techniques urgently needs to be quantified” the victim’s blood.” While Gestring accepts that DNA can be extremely helpful today are valid with certain in a minority of cases, “it is caveats, but we need to go back not a panacea”, he says. The and lay that sound foundation belief in DNA’s infallibility so these data are more reliable,” sometimes means that DNA says Bruce Goldberger, a forensic testing “happens at the expense toxicologist at the University of  of all the other ot her evidence, when Florida, Gainsville. more often than not it can say Achieving this will not be more than the DNA”. easy. How, for example, do you In fact, DNA is only helpful in determine error rates for around 10 per cent of murder cases, subjective judgements about says Baden, and even in these how a strand of hair looks? This cases there is usually plenty of  has led many analysts to argue other evidence as well. Where it that there is no error rate for can be extremely useful useful is in rape techniques like hair or fingerprint analysis, which claim to be able –Telling clues – if we read them right – and sexual assaults, where a large to find unequivocal matches between samples. samples. “I don’t FIRE TOOL MARKS subscribe to that,” says Gestring. Fire investigators hunting for Marks left by the tools of a criminal’s “Even computers have error rates. evidence of arson look for the trade can give the culprit away. Let’s find out what they are.” residues of flammable liquids in fire Using a screwdriver to prise open a In many areas of forensic debris.. A profile generated by gas debris window, for example, should leave evidence, scientists are beginning chromatography-mass spectrometry scratches unique to the tool. to do just that. Yet the tests are not (GCMS) can then be matched to a “It’s kind of up in the air as to how the only source of error, says John reference database. many lines make a match,” says Lentini at Applied Technical Unfortunately, the comparison is Nicholas Petraco of John Jay College Services in Marietta, Georgia. He visual, and therefore subjective. The in New York City. “Let’s see if we can wants forensic testing to take a speed at which the fire burns can put some numbers behind it.” lead from drug testing, where change the signature too. For Petraco, this means taking those running a trial are “blinded” To make analyses more robust, measurements of lines, features to details about the drug or  Jamie Baerncopf of Michigan State and the topography of tool marks , patient. “We need to control University,, East Lansing, and her University and feeding them into statistical expectation bias,” Lentini says. team are running profiles generated algorithms that produce plots in Despite the criticisms levelled by GCMS through statistical which data points appear in clusters. against it, the NAS report has been algorithms. This allows them to draw The more similar the patterns, the widely welcomed as a reminder a confidence interval around the tighter the cluster. He has analysed to those working in fields like data from a known ignitable liquid. lines from nine screwdrivers, so far, fingerprints or ballistics that they An analyst could be “95 per cent and can match them with an error need to do better. bett er. “They’ve been confident that anything within this rate of 3 per cent. cent. This should fall as very slow to come to the party,” circle is this liquid,” says Baerncopf. he adds more measuremen measurements. ts. says Fordham. “Now they’re going to have to.” ■ 28 February 2009 | NewScientist | 7

SPECIAL REPORT / GEOENGINEERING

EARTH’S PLAN B We may soon have no choice but to fiddle with the climate — but are we ready, asks atherine Brahic

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IN A room in London late last la st year, a group of British politicians were grilling a selection of climate scientists on geoengineering – the notion that to save the planet from climate change, we must artificially tweak its thermostat by firing fine dust into the atmosphere to deflect the sun’s rays, for instance, or perhaps even by launching clouds of mirrors into space. Surely the scientists gave such a heretical idea short shrift. After all, messing with the climate is exactly what got us into such trouble in the first place. The politicians on the committee certainly seemed to believe bel ieve so. “It is not sensible, is it? It is i s not a serious suggestion?” Had the question been posed a few years ago, most climate scientists would have agreed. But the mood is changing. In the face of potentially 8 | NewScientist | 28 February 2009

catastrophic climate change, the politicians and scientists all agreed that since cuts to carbon emissions will likely fall short we need to be exploring “Plan B”. Climatologists have hit a “social tipping point” says Tim Lenton of the University of East Anglia, UK. What’s more, respected scientists, including Nobel laureate Paul Crutzen, and groups such as the UK’s Royal Society, are already assessing the risks and benefits. Are we ready to try to t o turn down the thermostat? Who will wil l have the authority to push the button? And what would happen if one nation or well-intentioned “green finger” “There is no single global individual decided to go it alone? Geoengineering schemes range from thermostat the low-tech, such as planting trees, to which will sci-fi, such as placing mirrors in orbit bring about between Earth and the sun. All would universal work either by diverting solar energy cooling”

away from Earth or by sucking carbon dioxide out of the atmosphere to dampen the greenhouse effect (see diagram, page 10). Previously, the idea of tweaking the climate in this way was anathema to most scientists. Apart from the technical challenges and environmental risks, many argued that endorsing the concept might scupper international negotiations for a post-Ky pos t-Kyoto oto protocol to reduce global emissions. emissio ns. But it’s becoming clear that moves to cut global carbon emissions are too little and too late for us avoid the worst effects of  climate change. “There is a worrying sense that negotiations won’t lead anywhere or lead to enough,” says Lenton. “We can’t change the world that fast,” says Peter Liss, Liss, who is scientific adviser to the UK parliamentary committee investigating

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geoengineering. Extraordinary measures may now be the only way of  saving vulnerable ecosystems such as Arctic sea ice. What’s more, geoengineering could turn out to be relatively cheap. Early estimates suggest some schemes could cost a few billion dollars, dollars, small change compared to the cost of  slashing emissions – estimated by former World Bank chief economist Nicholas Stern to be at least 1 per of  global GDP per year. In his testimony to the UK politicians last la st year, John Latham of the National Center for Atmospheric Research in Boulder, Colorado, argued that all of the above reasons make it “irresponsible” not to examine geoengineering. While no one advocates deploying fleets of ships or launching space mirrors tomorrow, we need to know

Too little, too late to save the Earth from climate change

how Plan B is going to work, which means doing field tests. “If you wait for a climate catastrophe then you need to deploy fairly full-scale fairly quickly which means you won’t have time to look at the risks,” says Ken Caldeira of  the Carnegie Institution of Washington in Stanford, California. Yet, as with genetically modified crops, field testing has already sparked public resistance. This has been made clear with the various attempts in recent years over ocean fertilisation experiments. In 2007, a commercial firm called Planktos announced a plan to dump iron filings into the ocean off  the Galapagos Islands. Isl ands. More recently, a research ship set off to seed iron in the Southern Ocean. Both generated protests from environmentalists, such as ETC group, group, which feared they would damage ocean ecosystems. In many ways ocean fertilisation shows how other geoengineering schemes might be regulated. After the Planktos furore, the London Convention on marine pollution – ratified by b y over 80 countries – extended its remit to include geoengineering, and imposed a ban on commercial fertilisation. It has also announced its intention to strictly regulate scientific experiments. On 9 February, interested parties met to begin setting up experimental standards. Yet how we would implement geoengineering schemes on a global basis is less obvious, obvi ous, says lawyer David Victor of Stanford Sta nford University’s programme on energy and sustainable

development. “Whether all governments would need to OK a scheme in international waters or outer space is unclear,” he says. “Who would decide? And who would be responsible for redressing any unintended consequences?” For an example of the problems that would need to be ironed out, take a look at one of the more mature geoengineering schemes that could provide us with instant cooling today – pumping sulphate particles into the atmosphere to reflect the sun’s rays back into space. If one country forged ahead, it could have detrimental effects on others. A 2007 study suggested sulphate sunshades could trigger catastrophic drought in some regions. “There would inevitably be winners and losers, as there is not a single global thermostat which will bring about universal and consistent cooling,” says David Santillo, Santillo, senior research scientist at Greenpeace Research Laboratories in Exeter, UK. “By its very nature, if there is to be any purpose in geoengineering, geoengi neering, it would have to exert an impact over a vast proportion of the planet.” Victor estimates only a handful of nations or groupings – including Australia, Brazil, China, India, Russia, the European Union and possibly Japan – have the capability to unilaterally deploy atmospheric sunshades.. Only one of these has sunshades come close so far. In November 2005, Yuri Izrael, Izrael, former vice-chair of the Intergovernmental Panel on Climate Change and head of the >

DUMP THE SUNSHADE AT OUR PERIL What happens if we tinker, then change our mind? Will all of humanity be doomed? Not necessarily. Most methods that absorb carbon dioxide would take decades to work so stopping them is unlikely to have sudden undesired effects. In the most worrying scenario, sunshades would be deployed then removed. Preliminary results suggest aerosols would naturally have a stratospheric life of

about one year, making them reversible if needed. But there is a big catch. If they were deployed as an excuse to continue burning fossil fuels, the masked greenhouse effect would build up and other effects such as ocean acidificationwould continue. Sunshades would have to be replenished or the planet would be hit with the full force of pentup warming. Victor Brovkin

of the Max Planck Institute for Meteorology in Hamburg, Germany, calculates that if a sunshade were kept up for 200 years, then dismantled, the planet could warm by between 5 °C and 10 °C within decades. Such an event would trigger massive belches of methane from thawing permafrost and the breakdown of entire ecosystems. >

28 February 2009 | NewScientist | 9

SPECIAL REPORT / GEOENGINEERING Russian Global Climate and Ecology eoengineering eoengineeringweighed weighedup up Institute, tried to persuade his president, Vladimir Putin, that Russia should release 600,000 tonnes of  AEROSOLS sulphur aerosol particles into the Particles in the stratosphere atmosphere immediately. SPACE MIRRORS refect sun’s rays Orbiting mirrors defect sun’s rays READINESS: If any nation seriously considered READINESS: COST: $ going it alone, “there would almost COST: $$$ FLAW: risk o ozone depletion; FLAW: unknown weather eects; certainly be an internation international al diplomatic unknown weather eects, ails to prevent acidic oceans ails to prevent acidic oceans incident”, says Santillo. If a sunshade FORESTING triggered drought elsewhere, this could Trees absorb CO2 REFLECTIVE CROPS be interpreted as “hostile use” of  READINESS: Planting crops that ARTIFICIAL TREES COST: $ weather modification, in which case the refect more sunlight CO2 sucked rom air and FLAW: large land READINESS: action would fall foul of the UN stored underground area needed $ COST: READINESS: Convention on the Prohibition of  FLAW: large land area COST: $$$ Military or Any Other Hostile Use of  needed; ails to prevent FLAW: large geological acidic oceans cache needed Environmental Environme ntal Modification Techniques (ENMOD). During the CLOUD SEEDING Vietnam war, the US experimented with Atomising seawater creates clouds to refect sun’s rays rain seeding to disrupt the Ho Chi Minh READINESS: trail, which eventually led 70 nations, COST: $$ including the US, to ratify the treaty. But FLAW: unknown weather eects, patchy success; ails for it to be of any use, a drought-stricken to prevent acidic oceans nation would have to prove that a stratospheric sunshade was to blame and this could be difficult at best. “Almost everyone agrees that some form of international regulation and authorisation is necessary,” says John Shepherd, a deputy director of the UK BIOCHAR Tyndall Centre for Climate Change Agricultural carbon waste is burned and buried Research and chair of the Royal Society CARBONATE ADDITION READINESS: Ground limestone helps working group investigating COST: $$ oceans absorb CO2 FLAW: large land area needed geoengineering. But as for fo r how, “we READINESS: COST: $$ just don’t know”, he says. FLAW: unknown eects OCEAN FERTILISATION The obvious choice would be for the on ecosystems Iron lings stimulate C02-eating plankton UN to regulate geoengineering. READINESS: However, when New Scientist  enquired, COST: $$ FLAW: unknown eects on ecosystems the UN Framework Convention on Climate Change was unable to ost: ooling factor: eadiness: comment. According to Joan Ruddock, $ – Cheap relative to cutting emissions potential to – Within years $$ – Signicant compared to cost o cutting emissions change Earth’s – Within decades a UK minister serving in the $$$ – Cutting emissions might be cheaper energy budget – Within centuries Department of Energy and Climate Change, a powerful UN treaty on geoengineering in the wake of failed Washington DC describes a gathering huge challenges. But living in a much he attended at NASA’s Ames Research warmer world will be even more emissions talks tal ks is unlikely. “If we have Center in California in November 2006. unpleasant (see page 28). For now we entirely failed to bring the world community together to do the rather Astrophysicist Gregory Benford of the have time. It will be a couple of decades University of California, Irvine, before we know if international simpler things which we already announced that he wanted to “cut negotiations to wean ourselves off high understand very well,” she says, then through red tape and demonstrate devising a geoengineering agreement carbon fuels have had any success. what could be done” by injecting a If not, we may have no choice but “Only fools would be even more difficult. chalk-like substance into the Arctic to start tweaking the climate ourselves. find joy in Even if no nation did go it alone and stratosphere to reflect sunlight, using governments couldn’t agree on global “Only fools find joy in the prospect the idea of private funding. And Planktos of climate engineering,” says Caldeira. climate action, that still leaves the alarming would have forged ahead with ocean “There is a sense of despair desp air that we possibility of an individual deciding to engineering. fertilisation had no one stepped in. modify the climate on their own – a so- There is a are not seeing deep emissions cuts called “green finger”. finger”. Science historian sense of There is little doubt that planetary quickly, and that is pushing us to tinkering presents governments with consider these things.” ■ despair ” James Fleming of the Wilson Center in 10 | NewScientist | 28 February 2009

THIS WEEK

The cur curiou ious s case of the ageing ovaries Aria Pearson

YOUNG women with fertility problems caused by polycystic ovary syndrome mayhav may havee reason to take heart. Over a lifetime their chances of having children appear just as good as other ot her women’s, women’s, perhaps because egg production increases as they grow older. About 7 per cent of reproductiveage women have have PCOS,which PCOS, which features irregular periods, high levels of male hormones and greater numbers of developing follicles, or cysts, on the surface of their ovaries. In a normal norma l ovary, a few follicles appear appear each month, month, one or two of which mature and release an egg; the rest die off.

Fossilised fish are proof of ancient sex SEXUAL intercourse was far more common in early vertebrates than anyone imagined. So suggests a new study of ancient shark-like creatures called placoderms. Last year,John year, John Long of Museum Victoria in Melbourne, Melbourne, Australia, and colleagues found an embryo complete with umbilical cord inside a placoderm fossil from the Gogo formation in Kimberley,Western Kimberley, Western Australia. This “mother fish” pushed back evidence of internal fertilisation and live live birth by 200 million years to to 380 million years ago. But how placoderms managed to mate, considering some orders could could grow to be 6 metres long and all were heavily armoured, had been a mystery. mystery. Now, Long and a different team think they havethe have the answer. They examined the pelvic anatomy of three 380-million-year-old placoderm fossils belonging to the order Arthrodira and found a previously unnoticed “extra long

Women with PCOS ovulate less often because their extra follicles interfere with normal hormonal activity and stop follicles maturing past a certain stage. This is how PCOS lowers fertility. fertil ity. Now it looks lookslike like that that is not the end of the story. Miriam Hudecova and colleagues at Uppsala University in Sweden interviewed 91 women who were 35 or older and had been diagnosed with PCOS when younger. They found the women had undergone just as many pregnancies and borne as many babies, on average, as PCOS-free women of the same age. Some of  the women with PCOS had been treated for infertility, but more

than two-thirds had become pregnant without such help. Hudecova also examined most of the women and found that the ovaries of the older women with PCOS showed signs of being more active, with better hormone levels and more eggs available, than those of control women of the same age ( Human Reproduction, DOI: 10.1093/humrep/den482). “As they get older, ol der, the chance of 

fewer follicles mayhave may have the opposite effect: effect: it may stop the hormonal interference and cause follicles to release eggs normally. The hypothesis is backed up by other studies studies that hav havee shown that the menstrual cycles of  women with PCOS tend to become more regular as they age ( Human  Human 24).  Reproduction, vol 15, p 24). Marcelle Cedars, Cedars, a repro reprodu ducti ctive ve endocrinologist at the University of California, San Francisco, points out that it also chimes with “As women with polycystic a recent finding finding that hormone ovarian syndrome get older the chance of gettin getting g treatments can coax immature pregnantt may be higher” pregnan higher” follicles to produce eggs. “They might hit their getting pregnant may actually be reproductive peak a little bit later higher,” says Hudecova. than other women,” women,” saysRichard says Richard There maybe may be an explanation Legro,a gynaeco gynaecologist logist at Penn State for this. As women age, fewer Milton S. Hershey Medical Center follicles are produced each in Hershey, Pennsylvania. “When month, and in most this reduces we see more data data to thateffect that effect fertility. With PCOS, however, we’ll revise what we tell them.” t hem.” ■

bone” with “a long lobe projecting backwards”, says Long. The shape of the lobe indicates thatit articulates with cartilage, similar to the erectile claspers of modern-day sharks, he says (Nature, DOI: 10.1038/ nature07732). nature07732 ). These claspers would have been used to channel sperm into the female’s cloaca, a posterior opening also used for expelling waste,, in a similar way waste way to toda today’s y’s sharks, says Long. The team also re-examined two other arthrodire fossils from the same region. Small skeletons inside the specimens had been thought to be the debris of a cannibalistic dinner. But Long’s team now thinks that they were growing embryos. “The fish bones and armoury were not broken and crushed, as you’d expect if they were stomach contents,” says Long. While the original “mother fish” was from an obscure placoderm order, the arthrodires are from the largest. This raises the question of whether sexual intercourse evolved once, prior to the orders branching off, off, or many times independently, independently, says Gavin Young,, an expert on fish Young fish evolution evolution at the Australian National National University in Canberra. Rachel Nowak ■ 28 February 2009 | NewScientist | 11

THIS WEEK

SOUNDBITES

Camels, Heisenberg and quantum quantu m unce uncertainty rtainty WHAT does a biblical saying about a camel passing through thr ough the eye of a needle have to do with quantum uncertainty? Quite a lot, it turns out, since a mathematical concept called the “symplectic camel” promises to explain quantum uncertainty in simple classical terms. According to Heisenberg, it is impossible to measure both the momentum and position of a quantum particle accurately because those properties are interlinked. Measuring one therefore makes the other more uncertain. That’s because individual particles are considered parts of a probability “wave”,, in which many “wave” ma ny possible

combinations of position and momentum exist simultaneously. But Maurice de Gosson at the University of Vienna in Austria thinks that the inability to pin a particle down is due to something called symplectic geometry, not “The point that there quantum weirdness. De Gosson realised that a is, in effect, a ‘classical theorem in symplectic geometry uncertainty principle’, principle’, had parallels with the uncertainty is extremely intriguing” principle. The concept is known as the symplectic camel after the uncertainty in measurement, not biblical suggestion that it is easier quantum fuzziness ( Foundations for a camel to pass through the 194). of Physics, vol 39 p 194). eye of a needle than for a rich That is encouraging for those man to get into heaven. who hope to recast quantum De Gosson imagined that a ball mechanics in a more deterministic represents a cloud of possible way. “The point that there is, in positions for a quantum particle. effect, a ‘classical uncertainty principle’, is extremely intriguing,” says Michael Hall of the Australian National University in Canberra, who has also worked on the uncertainty principle. principle. However, it could be tricky to reproduce all the predictions of quantum mechanics using symplectic geometry, cautions Roderich Tumulka, who works on the foundations of quantum theory at Rutgers University in New Jersey. A key problem is whether an analogy like de Gosson’s represents a deep connection, or is simply si mply a coincidence.. John Norton, coincidence Norton, a philosopher of physics at the University of Pittsburgh in Pennsylvania, points out that de Gosson’s analogy fails to share one aspect of uncertainty with that of quantum mechanics. The uncertainty in position and momentum of a quantum particle is always greater than an amount represented by Planck’s constant, constant, a fundamental quantity in the quantum world. In de Gosson’s derivation, the constant’s value is unknown. “The characteristic quantity of quantum theory has to be put in my hand,” says Norton. Eugenie Samuel Reich ■

89mm w x 118mm deep ¼ pa page ge ver verti tica call

12 | NewScientist | 28 February 2009

He found that such a ball cannot be squeezed down to the size of  one particle to fit through a hole in a plane, because its geometry resists this in some way. way. The inability to squeeze the ball is analogous to singling out one particle and measuring its position and momentum exactly. De Gosson reckons this geometrical resistance creates the

“It was kind of like a religious conversion.” Stephen Tindale, former director of

Greenpeace UK, explaining that he and other leading environmentalists now back nuclear power because of the urgent need to curb carbon dioxide emissions (The Independent I ndependent,, London, 23 February)

“My family believe my brother was murdered.” David Fielding, whose brother was one of 2000 British people with

haemophilia who died after being given blood contaminated with HIV or hepatitis in the 1970s and 80s. Fielding gave evidence at an independent inquiry into the incident, which released its report this week (The Scotsman, Edinburgh, UK, 22 February)

“This was a digital rights grab.” Marc Rotenberg of the Electronic

Privacy Information Center in Washington DC, which had planned to file a complaint with the Federal Trade Commission over Facebook’s change to its contract with users, which appeared to give it perpetual ownership of their contributions. Facebook reversed the changes on 17 February (The New York  Times , 18 February)

“It’s just an SMS that’ll take 45 seconds to complete.” David Howman, director general of the World Anti-Doping Agency,

which on Tuesday refused to make immediate changes to out-ofcompetition compet ition rules for drug testing. Some athletes athletes object to a rule requiring them to notify drug testers of their whereabouts (AFP, 24 February)

“Why would the academy want to come after a little non-profit?” Kori Titus of Breathe California, host

to the “Hackademy” awards, which rate films according to their portrayal of tobacco use. The Academy of Motion Picture Arts and Sciences is claiming copyright infringement (The Sacramento Bee, 19 February)

For daily news stories, visit www.NewScientist.c www.NewScientist.com/section/science-news om/section/science-news

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four. One came from a flask labelled RMR-1029 that Ivins was responsible for at USAMRIID. The other seven came from cultures taken from that flask, only one of which was not located at USAMRIID. USAMRII D. So while these findings show the attack spores came from one of these cultures, the FBI has gone further in concluding the attack came directly from the RMR-1029 flask. Another question is how the attacker turned the water-based slurry of spores in the flask to the fine, dry powder in the letters. Joseph Michael of the Sandia National Lab in Albuquerque, New Mexico, used specialised electron microscopy to show that 75 per –The chief suspect committed suicide last year year–– cent of the attack spores had incorporated silicon into their been found were misleading. The coats while growing (see image, below). As spores taken directly full genome sequences revealed “no genetic differences at all”, says from RMR-1029 following the Keim. Instead, the researchers say, s ay, attacks had no silicon in their coats, and the other seven genetic the key clues came from a lucky discovery. A technician, also at matches had either none or a USAMRIID, had noticed patches the anthrax bacterium used in “The researchers say their of unusual-looking spores in investigations only nail the attack as the US army’ ar my’ss Ames cultures of the attack anthrax, strain. The FBI then obtained 1072 and recultured just those. Keim the source of the anthrax anthrax samples from the 18 labs and colleagues sequenced their spores, not the attacker” it knew to have Ames and got genomes and found 10 mutations several research groups, including that differed from the common lower percentage, the attack Keim’s, Keim’ s, to compare their genomes Ames sequence. Because the spores must have been recultured with that of the strain used in the spores made up a fraction of the before they were posted. total, these “minority” mutations During this process, they would attacks.. The hope was this would attacks uncover mutations that would hadn’t shown up initially. initial ly. have shed their coats, multiplied, finger one lab as the source. Next the team developed then turned back into spores. spores . Was Ivins’s level of expertise needed to But Keim and his colleagues told highly sensitive tests to screen the Baltimore meeting that initial all 1072 samples for four of the turn these recultured spores into reports that useful mutations had mutations. Eight samples had all dry powder? “What I am hearing is that the spores in the letter were not special. It would not take a lot Spore clues of time or equipment to make Electron microscopy of the anthrax sent to media outlets and politicians in 2001 provided vital clues to how the them,” says Keim. Michael’s spores were prepared images show the attack anthrax Silicon incorporated into the coats of the The attack samples contained clumps of contained spore clumps, unlike attack spores shows that they were spores, suggesting they had not been professionally produced powders. recultured before being posted professionally produced The FBI may have evidence to show Ivins was the link between RMR-1029 and the envelopes, though with civil suits from Ivins’ and the victims’ families pending, the bureau won’t be revealing it soon. For now, the researchers say their studies nail the spores as coming from the flask, but b ut not 5 μm 1 μm the identity of the attacker. ■

Behind the 2001 anthrax attacks Debora MacKenzie

KEY forensic evidence in the US anthrax attacks of 2001 has been revealed. The FBI had previously prevented the scientists involved from speaking publicly about their findings in case this interfered with court proceedings, but last August, after chief suspect Bruce Ivins committed suicide, suicide, the case collapsed and the FBI lifted many of the restrictions. This week, some of the scientists involved revealed their results at a scientific meeting in Baltimore, Maryland. These show how the FBI traced the spores used in the attacks to a single flask at a US government lab, but they don’t explain explai n why the FBI made Ivins – who worked at the US Army Medical Research Institute for Infectious Diseases (USAMRIID) – the chief suspect. In late 2001, envelopes containing dry anthrax spores were sent to a number of US media outlets and politicians, leading to five deaths. Later that year, Paul Keim at the Northern University of Arizona in Flagstaff identified

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28 February 2009 | NewScientist | 13

IN BRIEF

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Live near fast food, up your stroke risk

Supercell signal warns if tornado is on the way TORNADO hunters may have a new ally – electricity. Armed with only an antenna and a receiver, Ernst Schmitter of the University of Applied Sciences at Osnabrück in Germany and John Leeman from the Leeman Webb Storm Laboratory in Norman, Oklahoma, picked up low-frequency electromagnetic waves in a rotating storm known as a “supercell”. About 30 per cent of these storms spawn tornadoes. Schmitter and Leeman believe it is the supercell’s swirling action that generates the signal. When dust particles and droplets within the storm rub against

each other, they become oppositely charged. The lighter particles, which are mostly negative, get blown to the top of the funnel, while the heavier, positive ones sink to the bottom. As the separated particles rotate around the vortex, they emit low-frequency electromagnetic radiation ( Atmospheric Research, DOI: 10.1016/j.atmosr 10.1016/j.atmosres.2008.10.029). es.2008.10.029). This will improve tornado detection, which usually relies on teams of spotters and weather radar. Such methods can fall down in poor visibility, or when clouds or heavy rain block the microwaves used in radar. In contrast, low-frequency radiation can penetrate further through cloud and rain than microwaves. What’s more, an electromagnetic signal could be picked up instantly, whereas it takes time to refresh each radar scan.

Giant flying dinos had built-in airbags NOW we know how pterosaurs could once rule the skies. The biggest animals ever to fly had super-efficient bird-like lungs. Leathery-winged pterosaurs evolved 220 million years ago from the same group of reptiles that gave rise to crocodiles and, later, birds. How the animals with 10-metre wingspans powered their flight had been a mystery because they were thought to 14 | NewScientist | 28 February 2009

have inflexible ribcages, which would have made their breathing too inefficient for such exertion. Leon Claessens at the College of the Holy Cross in Worcester, Massachusetts, realised this view might be mistaken after pterosaur specialist Dave Unwin at the University of Leicester, UK, showed him a pterosaur fossil that suggested a “mobile ribcage”. r ibcage”. Further fossils confirmed it.

What’ss more, the fossils What’ revealed that the hollow bones contained air sacs linked to the dinosaur’s lungs. As in birds, such sacs would have passed air back and forth through the lungs, extracting oxygen more efficiently than in mammals. Intriguingly, the sacs were connected to a pneumatic system under the skin, which pterosaurs might have been able to inflate to adjust their wing shape, Claessens says.

PEOPLE who live in areas with many fast food restaurants are more likely to have a stroke than those living on healthier streets. So say Lewis Morgenstern of  the University of Michigan in Ann Arbor and colleagues. They divided Nueces county, Texas, Texas, into 64 areas of roughly equal population and found that between 2000 and mid-2003, there were 13 per cent more strokes in areas with an average of 33 fast food restaurants than in those with just 12 fast food joints. Accounting for factors such as socio-economic status, they calculate that each additional restaurant ups the risk of stroke by 1 per cent. Fast food restaurants may not be behind the high rates of stroke, says Morgenstern, who presented the study at the American Heart Association’s International Stroke Conference.. They may just Conference indicate other risk factors.

Born to look on the bright side A TENDENCY to seek out positive posit ive information informat ion may be in your genes. Elaine Fox at the University of Essex, UK, asked people to say which side of a screen target dots were on. Before the dots appeared, one side of the screen showed a positive or negative image and the other a neutral one. The time taken to spot the dots indicated which image was being looked at. People with two copies of a certain gene took longer to spot the dots when they appeared on the same side as a negative negative image compared with with the neutral image, and less time when they were on the side of a positive image. It shows they focus on positive images and resist negative ones ( Proceedings  Proceedings of the Royal Society  B, DOI: 10.1098/rspb.2008.1788).

For more on these stories go to www.NewScientist.com/section/science-news

What makes for a sexy landscape? BEAUTY is in the brain of the beholder: it seems the brains of men and women respond differently to beautiful landscapes. This may stem from the varied evolutionary pressures on the two sexes in our hunter-gatherer ancestors. A team led by Camilo Cela-Conde of the University of the Balearic Islands in Palma, Majorca, Spain, asked males and females whether photographs of natural and urban landscapes were beautiful or not. When they looked at a scene they deemed beautiful, both men and women had greater electrical activity in the parietal region, near the top of the brain. In women, this activation occurred in both halves of the brain, but in men it was restricted to the right hemisphere (Proceedings (Proceedings of  the National Academy of Sciences , Sciences , DOI: 10.1073/pnas.0900304 10.1073/pnas.0900304106). 106). This might reflect evolutionary differences, the team suggest. In early humans, humans, they say, men were hunters who needed mental maps of distance and direction, while women gathered plants for food and oriented themselves themselve s using landmarks. This fits with data that the left brain handles “categorical” spatial relations, such as landmarks, while the right evaluates “coordinate” data, such as distance and direction. The team say that what we find beautiful may have evolved from what our ancestors looked for in a habitat.     Y     M     A     L     A     /     N     O     T     R     E     T     S     A     M     N     I     A     I

Childhood abuse may leave ‘suicide marks’ on genes CHILD abuse appears to leave chemical “caps” on victims’ genes that last into adulthood and which may help to trigger suicide. Last year, Michael Meaney and his colleagues at McGill University in Montreal, Canada, found that in people who had been abused and later committed suicide, more genes were “switched off” in brain tissue taken from the hippocampus – a region involved in mood control – compared with people who had not been abused and who had died in other ways. To see if these differences might

be linked to the abuse itself or to suicidal tendencies in general, the team has now compared samples of hippocampal tissue from 24 people who killed themselves – half of whom were abused or neglected as children, half of whom were not – and from 12 people who were not abused and who died in other ways. The people who had both been abused and committed suicide had more chemical caps on their  Nr3c1 gene, compared with the other groups. Nr3c1 is thought to help modulate the response to

stress. They also had lower levels of the messenger RNA that corresponds to the expression of  Nr3C1  Nr3C1, indicating that the caps had suppressed the gene ( Nature Neuroscience , DOI: 10.1038/nn.2270). This suggests the changes in gene expression is linked to childhood abuse or neglect, and not to suicide. However, as people who were abused are more likely to kill themselves, Meaney suspects that the gene changes due to abuse may in turn predispose people to suicide.     B     A     L     S     C     I

Spotted in space, picked up on Earth IT’S been an extraordinary trip for space rock 2008 TC3. First spotted on 6 October hurtling through space towards Earth, it exploded over Sudan the next day. Now tiny pieces of it have been found. The discovery means that, for the first time, we have detected a space rock ahead of a collision with Earth, watched it streak through the atmosphere and then recovered pieces of it. According to Lindley Johnson of  NASA, who reported the find on 16 February at a United Nations meeting in Vienna, the rocks were found in the Sudanese desert by a team from the University of  Khartoum. They have an outer crust of singed material characteristic of meteorites. Most meteorites are thought to be pieces of asteroids, but pinning down exactly where they came from is usually impossible. Fortunately, 2008 TC3 was observed while still in space. “It’s often very difficult to get from a streak in the sky to what the orbit was,” says Allan Treiman of the Lunar and Planetary Institute in Houston, Texas. “But if they’ve got its location before it hit the atmosphere, they’re far better off – that’s t hat’s really wonderful.”

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Warmer Earth equals bigger dunes AT 500 metres tall, Earth’s largest sand dunes are already monsters – yet they are set to grow bigger as the world warms. Giant sand dunes are thought to form when smaller dunes crash into each other and pile up. To investigate if anything limits their size, Bruno Andreotti at the Denis Diderot University, Paris, and colleagues calculated what the atmospheric flow looks like around giant dunes. They found that the thickness of the lowest layer of the atmosphere – the boundary layer – controls dune size, with a thicker layer leading to larger

dunes (Nature  (Nature , vol 457, p 1120). “Once the dune becomes big enough to interact with the boundary layer it creates waves in the air. These waves feed back and interact with the sand below, keeping a lid on the dune size,” explains co-author Brad Murray of Duke University in Durham, North Carolina. Warmer air increases the thickness of the boundary layer, which explains why Earth’s largest dunes are found inland, in the hottest part of the desert. It also suggests that if global warming heats the planet in the right place, then dunes could get bigger.

28 February 2009 | NewScientist | 15

For all our daily technology stories go to www.NewScientist.com/section/tech www.NewScientist.com/section/tech

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Animated movies spring to life A 3D printer – a machine that “prints” small objects rather than pages – has been used for the first time to give the characters in an animated movie a far greater range of facial expressions than has been possible before. When fed with a design from a computer, a 3D printer gradually builds up objects by depositing layer upon layer of material. The materials can be plastic, nylon or metal powders, and each layer is set hard by a blast from a laser before the next one is laid down. These devices, devices, which are mainly used for prototyping products, offer major advantages over the traditional techniques for making the models used in stop-motion films like Wallace  & Gromit . Rather than painstakingly hand sculpting every facial expression, animators can instead 3D print many slightly different heads, says Martin Meunier, the “creature

supervisor” at Laika Entertainment in Portland, Oregon. The company made the animated movie Coraline , which opened in the US this month. By laying down layers just 16 micrometres thick – far finer than a human animator could sculpt – the printer offers greatly increased

“3D printers allow animators to capture almost a quarter of a million facial expressions” subtlety. This allows animators to capture almost a quarter of a million fine-grained facial expressions. “When you look at a lot of the models’ faces side by side you often can’t tell them apart,” Meunier says. “But when they are projected onto a cinema screen their subtle expressions really come alive.”

–Coraline ’s ’s models were printed layer by layer– layer –

Robots can’t tell friend from foe

Website will dish the dirt on foods IS IT best to buy local produce grown in a greenhouse or an imported alternative? Shoppers will soon have a powerful tool to help answer such conundrums: www.goodguide.com. On 9 March, the San Franciscobased website will add food from supermarkets around the globe to its existing roster of consumer safety and carbon-footprint ratings for non-food goods. If  a food product has a barcode, GoodGuide promises to rate it, revealing what it contains in terms of chemicals, colourings, additives and nutrition, as well as its environmental impact. “You could take 12 hours on 50 different sites checking animal rights, worker rights, anti-GMO sites or anti-irradiation sites. We aggregate all these issues in one place,” says GoodGuide’s founder Dara O’Rourke.

1

The number of cellphone chargers a household will need by 2012, when a universal device becomes available

THE idea that robots might one day be able to tell friend from foe is deeply flawed, says roboticist Noel Sharkey of the University of Sheffield in the UK. He was commenting on a report calling for weapon-wielding military robots to be programmed with the same ethical rules of  engagement as human soldiers. The report (www.tinyurl.com/ (www.tinyurl.com/ roboshoot), roboshoot ), which was funded by the Pentagon, says firms rushing to fulfil the requirement for onethird of US forces to be uncrewed by 2015 risk leaving ethical concerns by the wayside. “Fully

autonomous systems are in place right now,” warns Patrick Lin, the study’s author at California State Polytechnic in San Luis Obispo. “The US navy’s Phalanx system, for instance, can identify, target, and shoot down missiles without human authorisation.” While Sharkey applauds the report’s broad coverage of the issue, he says it is far too optimistic: “It trots out the old notion not ion that robots could behave more ethically than soldiers because they don’t get angry or seek revenge. revenge.”” But robots don’t have human empathy and can’t exercise judgement, he says, and as they can’t discriminate between innocent bystanders and soldiers they should not make judgements about lethal force.

“Whoever “Whoev er is hacking, please stop doing that” Peter Sunde of the Pirate Bay website appeals on Twitter.com for hackers to stop defacing the website of the International Federation of the Phonographic Industry which, alongside movie studios, has taken t aken Pirate Bay to court for alleged copyright breaches (Twitter, 18 February)

28 February 2009 | NewScientist | 17

TECHNOLOGY

Projector Projec tor phone phones: s: coo cooll app or visual pollution? The next technology to be installed in cellphones looks likely to be the video projector. But will anyone want or use them? Paul Marks

IF HEARING other other people’s people’s music fizzing out of tinny headphones annoys you, get ready for even more irritation: chip maker Texas Instruments (TI) has shrunk a video projector to the size of a raisin and it says the device is cheap enough to become the next must-have feature for cellphones. This means people could project their photos, videos and Powerpointstyle presentations on walls, tables or just about any other surface. But whilespecialists see some advantages in the technology, particularly in creating new ways to interact with cellphones, they also warn that that it raises fresh privacy and security issues.

What’s fuelling projection’ projectio n’ss move to the cellphone is the ongoing miniaturisation of the chips TI already uses in projection TVs. These digital light processing (DLP) chips contain thousands of  electromechanical mirrors that each represent a pixel. When a

is called the DLP Pico and has a resolution of 480 by 320 pixels. That chip is now being used in pocket-sized portable projectors and was launched in a cellphone for the first time at last l ast week’s Mobile World Congress in Barcelona, Spain. This Samsung phone lets users “Just as BlackB BlackBerry erry brough broughtt project an image about 1.3 metres wide. However, the device is email ema il to the restauran restaurantt unlikely unlike ly to achiev achievee mass adoption table, tabl e, this this mig might ht bri bring ng us Powerpoint presentations” because of its low resolution. So last week TI also launched pixel is to be illuminated, an a secondsecond-generat generation ion chip with electric field causes the mirror to a resolut resolution ion of 850 by 480 pixels pixels – tilt, sending light from red, green the same as a DVD player. and blue LEDs in turn to a lens That kind of resolution is what and then onto a screen. cellphone makers have been Last year, TI launched the first asking for, says Frank Moizio micro-scale projector chip, which of TI in Austin, Texas.

Three shakes and your phones are connected With the recession biting, the Mobile World Congress in Barcelona, Spain, last week was short on ground-breaking ground-breakin g technolog technological ical ideas. Cellphone-makers largely made the best of their existing product lines instead. Yet they are still filing patents on innovations for when the good times return – and Nokia reckons gestureactivated communication could be one of them. Its idea, in US patent application2009/0031258, 2009/0031258, is that if groups of friends want to, say, swap photos, they can connect their cellphones via Bluetooth using a series of gestures as a password – instead of having to work through on-screen menus. The technology hangs on the fact

that many phones now have motion sensors: when held sideways, for example, a phone might show a web browser in landscape format, then revert to portrait when it is righted. The patent describes software allowing users to record a short, unique sequence of movements – such as shaking to the left three times followed by a sharp upward move – that lets their phones link up. It’s a kind of tech-mediated Masonic handshake for people who wish to sidestep increasingly complex phone menus, say the inventors. The idea is still in the concept stage, says Frederique Sleazak of Nokia’s lab in Espoo, Finland – and the firm has not committed to launching it any time soon.

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Despite increasing the number of mirrors from 150,000 to over 400,000, the new chip is 20 per cent smaller – making it much more practical for cellphones. “We achieved thatby that by figuring out how to reduce the border border area around the mirrors on the chip and optimised the the way we connec connectt them electrically,” says Moizio.     S     E     R     U     T     A     E     F     X     E     R     /     A     C     M     Y     P     /     N     O     Y     R     A     M     S     I     X     E     L     A

–It’s the gesture that counts– counts – 18 | NewScientist | 28 February 2009

For more technology stories go to www.NewScientist.com/section/tech www.NewScientist.com/section/tech

Mega-laser to probe secrets Mega-laser of extrasolar planets

In most lighting conditions you can get a good image the size of a sheet of A4 paper, Moizio says. And power use is low enough for one battery charge to show a 2-hour movie. So if cellphone makers adopt the new chip en masse, and Samsung’s rivals Microvision, Motorola and 3M launch the projector phones they have promised, will people actually use them? And if so, how? At the University of Lancaster, UK, mobile interaction specialists Enrico Rukzio and Andrew Greaves have been researching just that. Rukzio thinks the dim image is going to be an issue that hints at more youthful, informal uses. “In a darkish pub, photos and video look great projected on the ceiling – and fine, too, on the side of a house at night. So I think teenagers will be the first adopters,” adopt ers,” he says. In research the pair presented at the Mobile Human Computer Interaction conference in Amsterdam, the Netherlands, last September, Greaves says the ability to have two screens – a tiny one on the phone and a large one on the wall – proved compelling for their group of volunteers (www. tinyurl.com/projpix). “They could keep personal info on

AN AWESOME laser facility, built to provide fusion data for nuclear weapons simulations, will soon be used to probe the secrets of extrasolar planets. The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory in California was declared ready for action earlier this month. Its vital statistics reveal it to be a powerful beast: its ultraviolet lasers can deliver 500 trillion watts in a 20-nanosecond burst. That power opens up new scientific possibilities. For instance, Raymond Jeanloz, an astronomer at the University of California, Berkeley, will use the –Cellphone cinema cinema–– device to recreate the conditions inside Jupiter and other larger planets, where pressures can be the phone and public content, like pictures or maps they wanted 1000 times as great as those at the centre of the Earth. to talk about, on the projection.” pr ojection.”  Jeanloz will fire the lasers at an iron There are downsides, though. sample 800 micrometres in diameter. “This is a promising, positive The intense heat will vaporise the technology if used in the right ri ght metal, generating a gas jet so context. If not, there could be powerful it will send a shock wave a lot of visual pollution,” p ollution,” warns through the iron, compressing it Greaves. “People could screen to over a billion times atmospheric material on a bus, say, s ay, that could be indecent – and that might even pressure. By measuring how the metal’s crystalline structure and lead to the need for legislation.” legis lation.” melting point change at these Rukzio thinks that after a few initial transgressions people may pressures, Jeanloz hopes to shed light on the formation of the hundreds of self-adjust: “Some kind of social giant exoplanets that we have protocol about public projection

might emerge. For instance, we don’t hear as many annoying ringtones as we used to,” he says. One privacy and security risk that must be addressed, he says, s ays, is accidental or malicious projection of somebody’s personal information, such as bank details. Robert Caunt, an analyst with market researcher CCS Insight in London, thinks the technology will let us in for more “death by Powerpoint” – poorly produced, overlong, special-effects laden presentations. “Just as the BlackBerry brought email to the restaurant table, this could bring us impromptu presentations we might rather not have,” he says. ■

discovered in the last two decades. “The chemistry of these planets is completely unexplored,” says Jeanloz. “It’s never been accessible in the laboratory before. b efore.”” Next year, Livermore teams will start work on experiments that could ultimately have an even bigger impact. They will use the lasers to ignite a fusion reaction in a ball of hydrogen isotopes. Other labs have triggered fusion, but not a selfsustaining reaction. The Livermore facility should deliver a big enough  jolt of energy to trigger a reaction that burns until the fuel is used up. The data produced will feed into attempts to design a commercial fusion power plant. The same reaction will also aid the management of the US nuclear

“It can deliver 500 trillion watts in a 20-nanosecond burst – opening up new scientific possibilities” weapons stockpile. It is more than 15 years since the US tested a nuclear weapon. Engineers use computer simulations to determine if warheads are in working order, but the models need to be calibrated using data from experiments like NIF’s fusion reactions.  Jim Giles, San Francisco ■         F         I         N

–Nuclear spark plug– plug– 28 February 2009 | NewScientist | 19

TECHNOLOGY with closely packed latex microspheres, each about 50 to 100 micrometres in diameter. By adding suitable surfactants and lowering the THE rings left behind by spilled coffee granules are being temperature to 4 °C, the team was coffee have inspired a new way to “assembled” by the varying able to control the evaporation make ultrathin coatings for LCD evaporation and convection rates and convection rates, causing and plasma flat-screens. in the fluid. Vakarelski and his the gold particles to move to the In LCDs, transparent transpa rent conductive colleagues figured that if they base of the latex balls where coatings are used to form an could mimic the process in a they settled to form rings and electrode on the surface of the controlled fashion, they could bridges. Once the liquid had screen, while in plasma TVs they create a pattern of granules of  evaporated, they were left with a provide a shield that t hat prevents other materials to form a network of connected gold electromagnetic fields from nanoscale conductive coating. nanoparticles ( Physical  Physical Review straying. The traditional Instead of coffee, they started 058303 ).  Letters, vol 102, p 058303) techniques for making such with a suspension of gold particles, “Our gold network is finer coatings include sputtering a fine each about 20 nanometres than spider’s silk and is also layer of indium tin oxide onto the across. The suspension was left conductive,” says Vakarelski Vakarelski.. He surface. ITO is highly conductive to dry on a glass plate covered reckons that gold nanonets and transparent to visible light, but the process is expensive, expens ive, How to make a nanonet requiring clean rooms and vacuum chambers. Ivan Vakarelski Vakarelski at the t he Institute of Chemical and Engineering Sciences in Singapore realised that coffee stains could point the way to a cheaper alternative. Spill coffee and the evaporating liquid drives coffee particles to the edges Latex microspheres are placed on a glass As the liquid evaporates, the gold of the spill – which ultimately slide and immersed in a suspension of nanoparticles settle in contact gold nanoparticles around the base of the spheres produces the circular stain. The

Golden ‘nanonets’ conduct themselves in an orderly way…

…while gold nanoparticles linger in cells, blocking genes GOLD nanoparticles could be an ideal way of delivering one of the hottest prospects in molecular medicine. The nanoparticles have successfully successfull y carried RNA molecules into human cells, where researchers hope they can be used to tackle everything from HIV to cancer. Over the past few years, stretches of “short interfering” RNA, or siRNA, siRNA, which are just over 20 bases long, have emerged as a powerful tool in biology because they are able to “turn off” target genes. They do this by selectively interfering with the messenger RNA that is the intermediate step between a gene and the protein it codes for. This means that siRNAs could 20 | NewScientist | 28 february 2009

also act as exquisitely targeted drugs, shutting down key genes from HIV and other viruses, or disabling the human genes linked with conditions from age-related sight loss to cancer. Getting large quantities of siRNA into human cells and protecting it from being broken down too quickly once inside is a tough challenge, however. Now a team led by Chad Mirkin of Northwestern University in Evanston, Illinois, has used gold nanoparticles to carry siRNA into cultures of human cells. The team’s delivery system consists of balls of gold just 13 nanometres across, each bearing about 30 short stretches of RNA bound to the gold by a connecting molecule. When these

particles were added to human cell cultures, they entered 99 per cent of the cells within 6 hours. “These particles go in better than anything else,” says Mirkin, although the mechanism of absorption is unclear. The researchers then tested how well the gold-borne siRNAs did their  job. They added siRNA-laden particles to cells carrying a loop of DNA bearing the gene for luciferase, the enzyme that gives fireflies their glow. A control

“siRNAs could act as exquisitely targeted drugs, shutting down genes from HIV and other viruses” group of cells was given the siRNA alone. Four days later, the reduction in the activity level of the gene in the gold-dosed cells was more than double the drop found in the control cells ( Journal of the American Chemical 

could make even better conductors than ITO coatings. The team has made coatings a few square centimetres in size in the laboratory and aim to increase this tenfold. tenfold. Unlike many new technologies, the nanonet process will be easy to scale up, says Vakarelski. The work has “considerable merit”, says Jennifer Lewis at the University of Illinois at UrbanaChampaign, an expert on the selfassembly of nanoparticles. “A key advantage of their approach is that the resulting networks are semi-transparent and their density can be tuned by varying the size of  the [latex-microsphere] template. template.”” AnilAnanthaswamy

■

Once dry, the microspheres are removed, leaving a mesh of gold nanowire

Society , DOI: 10.1021/ja808719p). “We can increase the lifetime of siRNA from minutes to hours – and sometimes even days,” says Mirkin. He reckons that as RNA is a salt, its high density on the particles’ surfaces creates an environment that inhibits the enzymes that break down RNA.  John Rossi, Rossi, an siRNA specialist at the City of Hope hospital in Duarte, California, is impressed that Mirkin’s team could deliver large amounts of siRNA to their cultured cells without obvious toxicity. Other delivery systems, such as lipids, tend to be toxic to cells at high doses, he notes. The next test will be to find out whether the particles perform as well in a living body as in the culture dish. “It’s early days, and there are a lot of delivery vehicles that work in cultured cells and haven’t worked in animals,” cautions Mark Kay, Kay, a gene therapist at Stanford University. Peter Aldhous ■

OPINION

Affordable drugs for all The patent system that has served drug companies so well may at last be changing to also help those who need drugs most, says Debora MacKenzie IT IS not a good idea to be sick s ick in a poor country. A drug for what ails you may well not exist – unless the same illness is common in rich countries too – and even if  it does exist, it is i s likely to be way beyond your means. Yet it is in poor countries that most of the world’s sick people live. This is the way things have been for years, partly because of a patent system that was supposed to encourage development of new pharmaceuticals. Against this background, the announcement this month by Andrew Andr ew Witty, CEO of GlaxoSmithKline, GlaxoSmithKline, the world’s second biggest pharmaceuticals firm, that GSK would free up access to patents relating to neglected diseases and cut the price of medicines for the poorest countries by at least 75 per cent has been heralded as a new dawn. GSK wants other companies to help it create a pool of patented substances and processes which anyone can use – on payment of  a royalty – to develop treatments for neglected tropical diseases. “It is right that we explore new ways of stimulating research that otherwise might not happen,” Witty says. Is big pharma finally showing its caring side? Well, yes and no. Though the gesture is not quite as selfless as it seems, examination of the complexities that underlie Witty’s statement suggest that the new dawn might be real. Under the existing patent system, a company gets a 20-year monopoly on drugs that it has developed, during which it can charge high prices to cover the costs of the R&D and make a profit. 22 | NewScientist | 28 February 2009

This rather discourages companies from investing in drugs that only poor people need, since they are unlikely to be able to pay enough to cover the companies’ costs. So companies will spend millions on a cure for impotence that men in rich countries will pay billions for, but won’t bother with a disease like malaria that kills one povertystricken child every 30 seconds. Where drugs do exist that would help people in poor countries, such as the newer anti-HIV treatments, they are mostly too expensive while still under patent. In the 1990s, pharmaceutical companies tried to tackle this problem by offering their patented drugs to African countries at big discounts,

in R&D, they will not be able to pay for research into new medicines. While there is some validity to this argument, research-based companies would in practice not be selling many patented products in the poor countries that buy generics, so their loss is small. What they really seem to be defending is the principle of stringent worldwide enforcement of  patents – what is tellingly coming to be known as “old patenting” patenting”.. Though no one disputes that companies need to reap rewards for the drugs they develop, there are signs that the old system is having to change. Governments are starting to take seriously the idea that rewards for R&D should be “de-linked” from the price of  the product. Last May, the World World Health Organization’s Organization’s member states approved a plan to “explore a range of incentive schemes, including the de-linkage of the costs of R&D and the price of  figuring it was better to sell health products”. These might them cheaply than not at all. But involve, for example, prizes what actually happened was that for innovation, funded by other companies, mainly in governments or other donors. India, started to sell their own In July UNITAID, UNITAID, a club of  generic versions. They were able countries formed in 2006 to buy to massively undercut even the drugs for the poor, proposed a drug companies’ discounts. patent pool that would allow drug Now, as world trade agreements companies to make patented take effect in countries like India, drugs available to poor countries this source of cheap versions at low prices while still selling of patented drugs is drying up. up. them at high prices elsewhere. Patent-holders warn that if they And this year, the US Food and have to compete with makers of  Drug Administration Administration will start generics, who do not have to invest awarding “priority “priority review vouchers”” (PRVs) vouchers (PRVs) – fast-track “Patented processes would licensing in the US – to any be available to researchers company that invents a drug for developing treatments for one of 16 neglected diseases. This diseases of the poor” is a “prize” “pri ze” worth having: PRVs

To comment comment on these stories go to www.NewScientist.com/section/opinion www.NewScientist.com/section/opinion

allow a company to market a lucrative new drug a year earlier than under normal FDA review. The vouchers can also be sold, for upwards of $300 million. Where does GSK’s offer fit into all this? It too wants a patent pool along the lines of the UNITAID scheme – though not of existing drugs but of experimental molecules and processes that drug companies have patented but are not necessarily using. These molecules and processes would be available for a royalty to researchers wanting to develop new treatments for the FDA’s 16 neglected diseases. The patent holder would retain the rights to the $300 million mill ion “prize” for every drug that emerged, yet it would not itself put up the money for the R&D involved, so the offer is not quite as generous as it may seem. It should bring real benefits just the same. As Witty says, it should encourage research that otherwise would not happen – though it is worth pointing out that such a move might not have been possible had the Gates Foundation and other philanthropic groups not been pouring money into neglected diseases, thereby creating a research community ready to take up such opportunities. Pharmaceutical companies know something has to give. President Barack Obama has called for “humanitarian licensing policies that ensure medications developed with US taxpayer dollars are available off-patent in developing countries”. He has the legal right to “march in” on any patented drug developed partly with US research money, and license it to others if the patent holder is not making fair use of it. The companies will resist that. But it seems they are beginning to accept that the patent system has to change so that it can ca n do what it was always supposed to: promote lifesaving drugs for all. ■ Debora MacKenzie is a New Scientist  correspondent based in Brussels

Guest columnist Amanda Gefter

Hidden religious agendas and how to spot them AS A book reviews editor at New Scientist , I often come across so-called science books which after a few pages reveal themselves to be harbouring ulterior motives. I have learned to recognise clues that the author is pushing a religious agenda. As creationists in the US continue to lose court battles over attempts to have intelligent design taught as science in federally funded schools , their strategy has been forced to… well, evolve. That means ensuring that references to pseudoscientific concepts like ID are more heavily veiled. So I thought I’d share a few tips for spotting what may be religion in science’s clothing. Red flag number one: the term “scientific materialism”. “Materialism” is most often used in contrast to something else – something nonmaterial, or supernatural. Proponents of ID frequently lament the scientific claim that humans are the product of purely material forces. At the same time, they never define how non-material forces might work. I have yet to find a definition that characterises non-materialism by what it is, rather than by what it is not. The invocation of Cartesian dualism – where the brain and mind are viewed as two distinct entities, one material and the other immaterial – is also a red flag. And if an author describes the mind, or any biological system for that matter, as “irreducibly complex”, let the alarm bells ring. Misguided interpretations of quantum physics are a classic hallmark of pseudoscience, usually of the New Age variety, but some religious groups are now appealing to aspects of quantum weirdness to account for free will. Beware: this is nonsense. When you come across the terms “Darwinism” or “Darwinists”, take heed. True scientists rarely use these terms, and instead opt for “evolution” and “biologists”, respectively. When evolution is described as a “blind, random, undirected process”, be warned. While genetic mutations may be random, natural selection is not. When cells are

described as “astonishin “astonishingly gly complex molecular machines”,, it is generally by breathless supporters machines” of ID who take the metaphor literally and assume that such a “machine” requires an “engineer”. If an author wishes for “academic freedom”, it is usually ID code for “the acceptance of creationism”. Some general sentiments are also red flags. Authors with religious motives make shameless appeals to common sense, from the staid – “There is nothing we can be more certain of than the reality of our sense of self” (James Le Fanu in Why Us? ) – to the silly – “Yer granny was an ape!” (creationist (creationi st blogger Denyse O’Leary). If common sense were a reliable guide, we wouldn’t need science in the first place. Religiously motivated authors also have a bad habit of linking the cultural implications of a theory to the truth-value of that theory. The ID crowd, for instance, loves to draw a line from

“If an author wishes for ‘academic freedom’, it is usually code for ‘the acceptance of creationism’” creationism’ ” Darwin to the Holocaust, as they did in the “documentary” film Expelled: No intelligence  allowed . Even if such an absurd link were justified, it would have zero relevance to the question of whether or not the theory of evolution is correct. Similarly, when Le Fanu writes that Darwin’s On the Origin of Species “articulated Species  “articulated the desire of many scientists for an exclusively materialist explanation of natural history that would liberate it from the sticky fingers of the theological inference that the beauty and wonder of the natural world was direct evidence for ‘A Designer’”, his statement has no bearing on the scientific merits of evolution. It is crucial to the public’s intellectual health to know when science really is science. Those with a religious agenda will continue to disguise their true views in their effort to win supporters, so please read between the lines. ■

Amanda Gefter is an editor for the Opinion section of New Scientist 

28 February 2009 | NewScientist | 23

OPINION LETTERS Double-cross helix?

Also of significant concern are questions about the scientific competence and experience of  particular laboratories to provide the correct information and interpret it appropriately. Processing DNA and getting a result is frighteningly easy, but obtaining the correct result and interpreting it reliably is complicated. Those who make claims which go beyond their expertise may be defrauding members of the public, with serious consequences.  London, UK 

 From Denise Syndercombe Court,  Barts and The London School of   Medicine and Dentistry Your editorial and articles on DNA testing raise the important issue of obtaining appropriate consent for an individual’s DNA to be tested (31 (31 January, p 3 and p 6; 6; 24 January, p 8). 8). The law in the UK is clear on this: it is illegal for a laboratory to test an individual’s DNA without proper informed consent. Even if companies refuse to test items such as discarded chewing gum and tissues, there is  From John Baker  still a danger of tests being You hail hail the UK legislation legisl ation conducted without proper consent. banning covert DNA testing. testi ng. Yet A laboratory receiving “consent the UK already leads the world in forms” by post with samples illegal DNA testing – the police are cannot establish that informed holding 857,366 DNA samples of  consent has been freely given. people illegally, as recently Only consent given in front of, determined by the European and verified by, an independent Court of Human Rights, in a person of appropriate standing, unanimous and damning such as a registered medical judgement (13 (13 December 2008, professional, can offer assurance p 7). 7). The UK holds 4.5 million DNA that the law is being complied samples, which probably cover with and so protect an individual most of the population through against their DNA being “stolen”. familial matching. I am far more

Enigma Number 1534

Head start SUSAN DENHAM Harey and Tortus decided to race from Harey’s house to school, a distance of a whole number of metres. They each ran at their own steady speed and when Harey reached school, Tortus was over half way there, but still had a twofigure number of metres to go. The next day they repeated the race, but this time Harey decided to

give Tortus a head start equal to the winning margin of the previous day. So Harey walked that number of metres away from his house in the opposite direction to school before the race started. Once again, Harey got to school first, ahead by a twofigure number of metres. The second winning margin had the same pair of digits as the first, but in reverse order. How far is it from Harey’s house to the school?

WIN £15 will be awarded to the sender of the first correct answer opened on Tuesday 31 March. The Editor’s decision is final. Please send entries to Enigma 1534, New Scientist, Lacon House, 84 Theobald’s Road, London WC1X 8NS, or to [email protected] (please include your postal address). Answer to 1528 Ad hoctagon: The area of the octagon is 140 cm2 The winner Ian Chantrell of Plymouth, UK

24 | NewScientist | 28 February 2009

threatened by this database and the possibilities, such as criminals planting my DNA at a crime scene, than I am by individuals covertly processing my DNA. In the case of paternity, historically only the mother has been sure, excluding maternity ward mix-ups. The father has a

the right to find out the truth. Should this give them the right to delve into the double helices of  anyone who they think can help answer their questions, including innocent parties, without consent? The UK parliament has decided that everyone’ everyone’ss genetic privacy must be respected. Drafting a law that selectively sel ectively strips rights of privacy from individuals who breach codes of sexual conduct may be impractical.

Holographology

small chance of having been cuckolded. Why should he be denied this information? Regardless, there is no realistic way of keeping people in ignorance, even if it were justifiable. I recommend routine verification of paternity at birth, with immediate destruction of  the samples. Chalfont St. Giles,  Buckinghamshire, UK   From Tony Park You raise concerns about the damage that covert genetic testing could do to families, yet simply asking for consent for a paternity test could damage the relationship, regardless of the result. In cases where the test shows infidelity or unexpected paternity, it is difficult to argue that the test is the cause of any relationship problems that may result. Similarly, Similar ly, the argument that great harm could result from finding out that your mother had been lying to you all your life is false. The harm is in the lying, not the finding out.  Dunlop, Ayrshire, UK  The editor writes: ■ People who who suspect sexual betrayal feel strongly they have

 From Antony Naylor  In the concept proposed by Marcus Chown in the article “All the world’s a hologram” (17 January, p 24), 24), the twodimensional surface of the sphere surrounding the universe is the hologram and the universe (including you) is a holographic image – a point glossed over by the oversimplified wording that appeared on the cover of the issue. There are two main problems with this theory. First, if there is a projected image, then some energy must interact with the hologram, either as transmitted or reflected energy. This cannot be electromagnetic radiation as its finite velocity would raise all sorts of problems with time, including predestination. So what is it and where does it come from? Secondly, if the universe is expanding then the elements of  the hologram must either be increasing in number or be being stretched. In the case of a black hole, the event horizon does increase in size as energy falls in, but there is no evidence that energy is falling into the universe. If the elements are being stretched, the graininess of the universe must be increasing. These issues can be resolved if one accepts that while the elements in the universe and those on the surface of the sphere can be mapped or transformed onto each other, neither the

For more letters visit www.NewScientist.c www.NewScientist.com/topic/letters om/topic/letters ■ Double-cross helix? ■ Truth or pare ■ Thou shalt not be popular ■ Day after day ■ Cosmic numerology ■ Science play time

elements inside nor those on the surface create each other. This concept still leaves the universe with graininess at a scale of  around 10-16 metres – compared with the Planck length of 10 -35 metres on the surface – but it does raise questions about the change in graininess as the t he universe has expanded, assuming the Planck length has always been the same. Wasaga Beach, Ontario, Canada

since paid particular attention to 28 units, sharply reducing the the hundred or so cattle and sheep amount of time left to complete visible from my kitchen window. the primary task. Overwhelmingly, these animals For n people, this overhead is align east-west. Frequently, Fr equently, this equivalent to (n × (n-1))/2 which appears to be a response to strong is the number of unique pairs winds, driving rain or fierce sun. that can be chosen from the Even in tranquil times, there is a people communicating with clear east-west preference. It each other. Try it. seems animals in Australia march I would recommend reading to a different drum.  Parkinson’s Law: Or the pursuit of  Grazing kangaroos show no  progress.. It’s must for scientists,  progress alignment preference at all. engineers and managers.  Foster, Victoria, Australia Stoke Gabriel, Devon, UK 

Debit risk  From Tim McCormack Mark Buchanan’s discussion of “unknown unknowns” (24 January, p 32) 32) could usefully be applied to banks’ assumptions of credit risk exposure. Some use Monte Carlo simulations to calculate an acceptable level of  value at risk. These use tables of  probability of loans defaulting, provided by the rating agencies. One problem with this method is that the probability probabilit y of any event occurring during the Monte Carlo Talk isn’t cheap simulation depends on the number of iterations of the  From Ted Lovesey simulation performed. Mark Buchanan refers to In 1000 iterations there may be humourist C. Northcote a 10 per cent chance of an a n “AAA”“AAA”Parkinson’s ideas about rated bond failure being included committees (10 (10 January, p 38). 38). Parkinson’s suggestions have in the results. If by chance an AAA failure shows up in such more far-reaching applications a simulation run, it will produce than just committee size. When working on a project to a spike in the tail of the results r esults graph and is likely to be dismissed reduce the crew workload in a as an improbable event. large anti-submarine aircraft, Why, then, include the I was continually being pressured possibility of an AAA default to increase the crew size. in the first place? In fact, such an increase would have added to the problem.  Foyers, Invernessshire, UK  This is because there is a “communications overhead” created by people interacting Magnetic cattle with each other. Say there  From Michael Kellock were 1 unit of communication You reported on research, based overhead for two people. With on a large number of satellite three people, the overhead for all photos, showing that cattle and three communicating together some wild grazing animals align increases to 3 units – one for each themselves predominantly along two-way conversation available. north-south lines, suggesting an By the time eight crew members awareness of the Earth’s magnetic are communicating, the overload field (30 (30 August 2008, p 10). 10). I have has risen exponentially to

Lead balloon  From James Sandemans I enjoyed Paul Collins’s article on metal balloons down the ages (10 January, p 44). 44). I am not sure, however, about his remark that, since 1941, “no more metal-clads have taken to the skies”. s kies”. I seem to recall reading, 30 or 40 years ago, of a successful project at the Massachusetts Institute of Technology to design, build and fly a balloon constructed entirely of lead. Glasgow, UK  The editor writes: ■ MIT’s neighbours at the consultancy Arthur D. Little flew both a lead balloon and a dirigible in May 1977: see photos at www. leadballoon.notlong.com.. The US leadballoon.notlong.com TV programme Mythbusters programme Mythbusters also managed to loft a balloon made of  lead foil in January 2008.

Holy herd  From Zoe Hudson David Robson discussed the herd mentality in humans (7 February, p 13). 13). On the rare occasions that I have been to church, I witnessed the power of  singing as part of a congregation and the connection you feel with those standing next to you. I found myself caught up in the t he moment with emotions of o f unity, purpose, elatedness and (unusually for me) spirituality.

From such experiences I can appreciate how contagious the belief in a god could be, especially when one is feeling particularly lost in life. Reinforcing faith through mass worship is evident in religious holidays, pilgrimages and ritualistic behaviour. I believe the herd mentality is fundamental to the persistence of organised religion. Oxford, UK 

For the record ■ We wrongly stated that the World

Health Organization recommended in September 2008 that the electronic cigarette be banned (14 February, p 33). 33 ). The WHO in fact stated that it did not consider the electronic cigarette to be a legitimate therapy for smokers trying to quit. ■ We said that in 1709 “from Czechoslovakia in the east… everything turned to ice” (7 (7 February, p 46). 46). No such country existed in 1709. It was founded in 1918 and split into the Czech Republic and Slovakia in 1993. ■ Our picture of the starfish Luidia sarsi was upside down (24 January, p 36). 36).

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28 February 2009 | NewScientist | 25

OPINION INTERVIEW Photography: Michael Struik

Universe on her shoulders Next month abiola Gianotti takes over as head of ATLAS at the Large Hadron Collider at CERN in Switzerland. The largest experiment of its kind, it could answer some of the mysteries of the universe. She talks to Anil Ananthaswam Ana nthaswamy y about dark matter and deep truths

What are your thoughts on becoming the first woman to head a particle physics experiment at the LHC?

CERN is such a rich environment: there are people from all over the world, young students work with established scientists and Nobel prizewinners. So geographical origin, age and gender make no difference here. I don’t do n’t feel there is anything special about a woman leading a big scientific project. On the other hand, I hope that as a woman scientist sci entist who has achieved a level of visibility in a big experiment like ATLAS, ATLAS, I can be an encouragement to young women who are thinking of a scientific career. Why did you decide to become a particle physicist?

I came to physics from very far away. When I was a young girl, I loved art and music. I had been studying piano quite seriously serio usly at a conservatory and had taken courses in high school targeted towards literature, languages like ancient Greek and Latin, philosophy and history of art. I loved these subjects but I was

PROFILE Fabiola Gianotti has a PhD in experimental sub-nuclear physics from the University of Milan, Italy. She joined CERN in 1987, working on various experiments including UA2 and ALEPH on the Large Electron Positron collider, collider, the precursor to the LHC at CERN. Gianotti is a member of the Physics Advisory Committee at Fermilab, the particle physics laboratory at Batavia, Illinois. A trained pianist, she has a professional music diploma from the Milan Conservatory.

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also a very curious little girl. I was fascinated by the big questions. Why are things the way they are? This possibility of answering fundamental questions has always attracted me – my mind, my spirit, everything. So, when I had to choose what I wanted to do with my life, I thought t hought that physics could answer these big questions in a more concrete way than philosophy. philosophy. I was right – in that I’m very happy now. Give us a sense of the size and scope of ATLAS.

The ATLAS collaboration consists of almost 3000 physicists from 169 institutions, 37 countries and five continents. ATLAS is the biggest detector ever built at a particle collider and its spectacular size strikes people immediately when they visit the underground cavern it is housed in – it’s as big as a five storey building. This size is combined with an enormous complexity. There are 100 million independent electronic signals that we need to record in order to reconstruct the hundreds of particles produced in every proton-proton collision. The trajectories of the particles must be reconstructed with micrometre precision. This amazing combination of size, complexity and precision has made the technology very challenging. ATLAS and indeed the other detectors at the LHC are instruments without precedent.

itself, physics beyond the so-called standard model [which explains all known particles and the forces that act upon them]. We expect to find answers to some fundamental questions and mysteries, many of which have been with us for decades. For instance, i nstance, what is the origin of mass? It’s a question related to the existence of the Higgs boson. boson . Are there other forces of nature, in addition to the four forces we already know of? Are there additional dimensions of space? What is the composition of the universe’s dark matter? matter ?

What are the key goals of ATLAS?

ATLAS will sift through particles created by extremely high-energy proton-proton collisions. We are starting on a fantastic scientific journey. We believe that at this energy scale, new physics should manifest

What would you personally like to see ATLAS discover first?

Dark matter. I would be very, very happy if we discover the particle that explains 20 2 0 per cent of the universe’s composition. Accelerators like

For more on these stories go to www.NewScienti www.NewScientist.com/section/opinion st.com/section/opinion

instruments which are at the cutting edge of technology in various sectors, from electronics to cryogenics, and which have spin-off benefits to society. Thirdly, these projects have been carried out in an international environment, with physicists, engineers and technicians from all over the world, bringing nations together through science and breaking political barriers. In our project, we have people from countries that are historically not the best of friends. What’s the mood at CERN, given that the start of the LHC got delayed?

The inauguration of the LHC on 10 September was a big success, there was a lot of  excitement. And then 19 September, when the accident happened, was like a cold shower. There was of course big disappointment, especially among the younger people, who

“We have to find something, and nature could well present us with surprises” were so excited and so happy during the first few days when the LHC was circulating single beams. On the other hand, this is a very difficult project technologically. It was started almost 20 years ago and will last for another 20 years, and such hiccups have to be taken into account. We are on a path which otherwise has been very successful until now, and will be very successful. We just have to be a little bit more patient. The LHC and ATLAS could potentially reveal some deep truths about how the universe works. What do you feel when you think about it?

the LHC allow us to study the infinitely small – the basic constituents of matter – and this can tell us about the structure and evolution of the universe, stressing the link between the infinitely small and the infinitely big. Have you thought about what would happen if no new physics is discovered at the LHC?

It is a good question, but it’s difficult to answer. Based on what we have learned from experimental and theoretical theoretica l work over the last few decades, there must be something new at the energy scales that the LHC will offer. Perhaps there will be just one Higgs boson,, or a new mechanism playing the same boson role, but we expect more. We know that the standard model is not a complete theory of  elementary particles, because it cannot

answer all our questions. We expect it to start to break down at the energy scale of the LHC. There must be new physics there. Perhaps they won’t be the answers that we have in mind, but there must be answers. Nature could well present us with surprises and this will be one of the most mo st exciting possibilities. After all, research is about looking for something that we don’t know a priori. What has it been like working on ATLAS?

Building the LHC and experiments like ATLAS is an unprecedented scientific, technological and human adventure. What makes my life as a scientist at CERN so special is the combination of three elements. One is the exciting physics goals. Then, to address these questions, we had to develop high-tech

Feelings of excitement, of course, and the awareness of being close to something very important and great for humankind. Fundamental research is a duty and a need of human beings. The 13th century Italian poet Dante said that we were not created to live as animals but to pursue virtue and knowledge. As human beings, the pursuit of  fundamental research and knowledge is a need for us, which separates us from animals or vegetables. It is like the need for art. Research bring knowledge, and knowledge brings progress, always. a lways. If we discover something fundamental at the LHC, it will be a bit like going to the heart of the universe. When you are getting closer to the fundamentals, to the basic questions of where the universe comes from and where it is going, there’s a very special feeling. ■ 28 February 2009 | NewScientist | 27

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COVER STORY

Survivi viving ng in a warrmer world wa If the planet warms by 4 ºC – as it might this century – it will change beyond all recognition. A radical new world order may be our only hope, says Gaia Vince

A

The cities that escape the floods may still be consumed by desert

LLIGATORS basking off the English coast; a vast Brazilian desert; the mythical lost cities of Saigon, Sai gon, New Orleans, Venice and Mumbai; and 90 per cent of humanity vanished. Welcome to the world warmed by 4 °C. Clearly this is a vision of the future that no one wants, but it might happen. Fearing that the best efforts to curb greenhouse gas emissions may fail, or that planetary climate feedback mechanisms will accelerate warming, some scientists and economists are considering not only what this world of the future might be like, but how it could sustain a growing human population. They argue that surviving in the kinds of numbers that exist today, to day, or even more, will be possible, but only if we use our uniquely human ingenuity to cooperate as a species to radically reorganise our world. The good news is that the survival of  humankind itself is not at stake: the species could continue if only a couple of hundred individuals remained. But maintaining the current global population of nearly 7 billion, or more, is going to require serious planning. Four degrees may not sound like much – after all, it is less than a typical temperature change between night and day. It might sound quite pleasant, like moving to Florida from Boston, say, or retiring from the UK to southern Spain. An average warming of the entire globe by 4 °C is a very different matter, however, and would render the planet unrecognisable from anything humans have ever experienced. Indeed, human activity has and will have such a great impact that some have proposed describing the time from the 18th century onward as a new geological era, marked by human activity. “It can be considered the Anthropocene,” says Nobel

prizewinning atmospheric chemist Paul Crutzen of the Max Planck Institute for Chemistry in Mainz, Germany. Ger many. A 4 °C rise could easily occur. The 2007 report of the Intergovernmental Panel on Climate Change, Change, whose conclusions are generally accepted as conservative, predicted a rise of anywhere between 2 °C and 6.4 °C this century. And in August 2008, Bob Watson, former chair of the IPCC, I PCC, warned that the world should work on mitigation and adaptation strategies to “prepare “pr epare for 4 °C of warming” war ming”.. A key factor in how well we deal with a warmer world is how much time we have to adapt. When, and if, we get this hot depends not only on how much greenhouse gas we pump into the atmosphere atmospher e and how quickly, but how sensitive the world’s climate is to these gases. It also depends whether “tipping points” are reached, in which climate feedback mechanisms rapidly speed warming. According to models, we could cook the planet by 4 °C by 2100. Some scientists fear that t hat we may get there as soon as 2050. If this happens, the ramifications for life on Earth are so terrifying that many scientists contacted for this article preferred not to contemplate them, saying only that we should concentrate on reducing emissions to a level where such a rise is known only in nightmares. “Climatologists tend to fall into two camps: there are the cautious ones who say we need to cut emissions and won’t even think about high global temperatures; and there are the ones who tell us to run for the hills hill s because we’re all doomed,” says Peter Cox, Cox, who studies the dynamics of climate systems at the University of Exeter, UK. “I prefer a middle ground. We have to accept that changes are inevitable and start star t to adapt now.” > 28 February 2009 | NewScientist | 29

Bearing in mind that that a genera generation tion alive today might experience the scary side of  these climate predictions, let us head bravely into this hotter world and consider whether and how we could could survive survive it with most of our population intact. Whatmight this future hold? The last time the world experienced temperature rises of this magnitude was 55 million years ago, after the so-called Palaeocene-Eocene Thermal Maximum Maxi mum event. event. Then, the culprits were clathrates – large areas of frozen, chemically caged methane – which were released from the deep ocean in explosive belches that filled the atmosphere with around ar ound 5 gigatonnes of carbon. The already warm planet rocketed by 5 or 6 °C, tropical forests

water will evaporate faster, leaving drought across Asia. Bangladesh stands to lose a third of  its land area – including its main bread basket. The African monsoon, although less well understood, is expected to become more intense,, possibly leading to a greening of the intense semi-arid Sahel region, which stretches across the continent south of the Sahara desert. Other models, however,predict however, predict a worsening of  drought all over Africa. A lack l ack of fresh water will be felt elsewhere in the world, too, with warmer temperatures reducing soil moisture across China, the south-west US, Central America, most of South America and Australia. All of the world’s major deserts are predicted to expand, with the Sahara

”Humans will survive as a species, but the cull this century will be huge” sprang up in ice-free polar regions, and the oceans turned so acidic from dissolved carbon dioxide that there was a vast die-off of sea s ea life. Sea levels rose to 100 metres higher than today’s and desert stretched from southern Africa into Europe. While the exact changes would depend on how quickly the temperature rose and how much polar ice melted, we can expect simila r scenarios to unfold this time around. The first problem would be that many of the places where people live and grow food would no longer be suitable for either. Rising sea levels – from thermal expansion of the oceans, melting glaciers and storm surges – would drown today’s coastal regions in up to 2 metr es of water initially,and initially,and possibly much more if  the Greenland ice sheet and parts of Antarctica were to melt. “It’s hard to see west Antarctica’s A ntarctica’s ice sheets surviving the century, meaning a sea-level rise of at least 1 or 2 metres,” says climatologist James Hansen, Hansen, who heads NASA’s Goddard Institute for Space Studies in New York. York. “CO2 concentrations of 550 parts per million [compared with about 385 ppm now] would be disastrous,” he adds, “certainly leading to an ice-free planet, pla net, with sea level about 80 metres higher… higher… and the trip trip getting there would be horrendous.” horr endous.” Half of the world’s surface lies in the tropics, tro pics, between 30° and -30° latitude, and these ar eas are particularly vulnerable to climate change. India, Bangladesh and Pakistan, for example, will feel the force of a shorter but fiercer Asian monsoon, which will probably cause even more devastating floods than the area suffers now. Yet Yet because the land la nd will be hotter, this 30 | NewScientist | 28 February 2009

reaching right into central Europe. Glacial retreat will dry Europe’s rivers from the Danube to the Rhine, with similar effects in mountainous regions including the Peruvian Andes, and the Himalayan and Karakoram ranges, which as result will no longer supply water to Afghanistan, Pakistan, China, Bhutan, India and Vietnam. Along with the exhaustion of aquifers, all this will lead to two latitudinal dry belts where human habitation will be impossible, say Syukuro Manabe of Tokyo University, Japan, and his colleagues. One will stretch across Central America, southern Europe and north Africa, south Asia and Japan; while the other will cover Madagascar, southern Africa, the Pacific Islands, and most of Australia and Chile (Climatic Change, vol64, p 59). 59).

The world: 4°C warmer No one knows exactly what this world will lookl ike, but models provide insights into into orced human migrations and our uture power generation

Arctic passage With no sea ice, this valuable shipping routeis open all year, providing transportation links beween habitable zones in Canada and Russia

Canada Reliable precipitation and warmer temperatures provide ideal growing conditions or most o the world's subsistence crops

South-west US Desertifcation led to the last Desertifcation inhabitants o this region migrating north. The Colorado river is a mere trickle. The land is used or solar arming and geothermal energy

Peru Deglaciation means this area is dry and uninhabitable

The high life The only places we will be guaranteed enough water will be in the high latitudes. latitudes . “Everything in that region will be growing like mad. That’s where all the life will be,” b e,” says former NASA scientist James Lovelock, Lovelock, who developed developed the “Gaia” theory, which which describes the Earth as a self-regulating entity. “The rest of the world will be largely desert with a few oases. oases.”” So if only a fraction of the planet will w ill be habitable, how will our vast population survive? Some, like Lovelock, are less than optimistic. “Humans are in a pretty difficult position and I don’t think thi nk they are clever enough to handle what’s ahead. I think they’ll survive as a species all right, but the cull during this century is going to be huge,” he >

Western Antarctica Unrecognisable now.Densely Unrecognisable populated with high-rise cities

Food-growing zones / Compact high-rise cities

Uninhabitable desert

Greenland Greenland’sice sheet Greenland’s will be melting rapidly

Scandinavia/UK/Northern Russia/Greenland

Siberia

Compact high-rise cities would provide shelter or much o the world's population

Reliable precipitation and warmer temperatures provide ideal growing conditions or most o the world's subsistence crops

Southern Europe Deserts have encroached on the continent, contin ent, rivers have have dried up and the Alps are snow-ree. Goats and other hardy animals are kept at the ringes

North Africa/Middle East/ Southern US Solar Energy Belt stretches or thousands o kilome kilometres, tres, employing a mixture o photov photovoltaic oltaic and solar thermal energy. At requent intervals a high voltage direct-current substation sends power north

Southern China Dried rivers and aquiers mean this region has been abandoned. Intense monsoons have helped erode the land, leaving a dustbowl

Amazon

Asia

Desert

Africa Mostlydesert, though some models show greening o the Sahel

Most o the Himalayan glaciers have melted, with repercussions or many o the major rivers in the region. Bangladesh is largely abandoned, as is south India, Pakistan and Aghanistan. Isolated communities remain in pockets

Patagonia

Vanished beneath the sea

Australia

Melted glaciers revealed a new arable zone, although the poor soils needed preparation

Uninhabitable due to oods, Uninhabitable drought or extreme weather

Polynesia

In the ar north and Tasmania, compactcities house people and crops are grown. The rest o the continent is given to solar energy production and uranium mining or nuclear power

Potential or reorestation

Land lost due to rising sea levels, assuming a 2-metre rise

Solar energy

Geothermal energy

New Zealand Unrecognisable. This densely populated populate d island state has high-rise cities and intensive arming

Wind energy

28 February 2009 | NewScientist | 31

says. “The number remaining at the end of  the century will probably proba bly be a billion or less.” John Schellnhuber of the Potsdam Institute for Climate Impacts Research in Germany is more hopeful. The 4 °C warmer world would be a huge challenge, he says, but one we could rise to. “Would we be able to live within wit hin our resources, in this world? I think it could work with a new division of land and production. pr oduction.”” In order to survive, humans may need to do something radical: rethink our society not along geopolitical lines but in terms of  resource distribution. distr ibution. “We are locked into a mindset that each country has to be sel fsustaining in food, fo od, water and energy,” Cox says. “We need to look at the world afresh afres h and see it in terms of where the resources resour ces are, and then plan the population, food and energy production around that. If aliens came to Earth they’d think it was crazy that some of the driest parts of the world, such as Pakistan and Egypt, grow some of the thirstiest crops for export, like rice.” r ice.” Taking politics out of the equation may seem unrealistic: conflict over resources will likely increase significantly as the climate changes, and political leaders are not going to give up their power just like that. Nevertheless, overcoming political hurdles may be our only chance. “It’s too late for us,” says President Anote Tong of Kiribati, a submerging island state in Micronesia, which has a programme of gradual migration to Australia and New Zealand. “We need to do something

” We will need to abandon huge areas and move people to where the water is” drastic to remove national boundaries.” bounda ries.” Cox agrees: “If it turns out that the only thing preventing our survival was national barriers then we would need to address this – our survival is too important,” impor tant,” he says. Imagine, for the purposes of this thought experiment, that we have 9 billion people to save – 2 billion more than t han live on the planet today. A wholescale relocation of the world’s population according to the geography of  resources means abandoning huge tracts of  the globe and moving people to where the water is. Most climate models agree that the far north and south of the planet will see an increase in precipitation. In the northern hemisphere this includes Canada, Siberia, Scandinavia and newly ice-free parts of  Greenland; in the southern hemisphere, Patagonia, Tasmania and the far north of  Australia, New Zealand and perhaps newly ice-free parts of the western Antarctic coast. If we allow 20 square metres of space per person – more than double the minimum habitable space allowed per person under English planning regulations – 9 million people would need 18,000 square kilometres of land to live on. The area of Canada alone al one is 9.1 million square kilometres and, combined

with all the other high-latitude areas, such as Alaska, Britain, Russia and Scandinavia, there should be plenty of room for everyone, even with the effects of sea-level rise. These precious lands with access to water would be valuable food-growing areas, as well as the last oases for many species, so people would be need to be housed in compact, highrise cities. Living this closely together will bring problems of its own. Disease could easily spread through the crowded population so early warning systems will be needed to monitor any outbreaks. It may also get very hot. Cities can produce 2 °C of additional localised warming because of  energy use and things like poor reflectivity of  buildings and lower rates of evaporation from concrete surfaces, says s ays Mark McCarthy, an urban climate modeller at the UK Met Office’s Hadley Centre. “The roofs could be painted a light, reflective colour and planted with vegetation,” McCarthy suggests. Since water will be scarce, food production will need to be far more efficient. Hot growing seasons will be more common, meaning that livestock will become increasingly stressed, and crop growing seasons will shorten, according to David Battisti of the University of Washington in Seattle and his colleagues (Science, vol 323, p 240). We will need heat and drought-tolerant crop varieties, they suggest. Rice may have to give way way to less thirsty thirs ty staples such as potatoes. potatoes.

Vegetarian dystopia

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This will probably be a mostly vegetarian world: the warming, acidic seas will be largely devoid of fish, thanks to a crash in plankton pl ankton that use calcium carbonate to build shells. Molluscs, also unable to grow their carbonate shells, will become extinct. Poultry may be viable on the edges of farmland but there will simply be no room to graze cattle. Livestock may be restricted to hardy animals such as goats, which can survive on desert scrub. One consequence of the lack of cattle will wil l be a need for alternative fertilisers – processed human waste is a possibility. Synthetic meats and other foods could meet some so me of the demand. gr own on With fiercer and shorter Cultivation of algal mats, and crops grown monsoons, droughts will floating platforms and in marshland could also contribute. quickly follow floods

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As desert encroaches on fertile land, as it has near Dunhuang, China, people will be forcedpolewards

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Supplying energy to our cities will also require some adventurous thinking. Much of it could be covered by a giant solar so lar belt, a vast array of solar collectors that would run across north Africa, the Middle East and the southern US. Last December, David Wheeler and Kevin Ummel of the Center for Global Development in Washington DC calculated that a 110,000-square-kilometre area of  solar panels across Jordan, Libya and Morocco would be “sufficient to meet 50 to 70 per cent of worldwide electricity production, or about three times [today’s] power consumption in Europe”. High-voltage direct current transmission lines could relay this power to the cities, or it could be stored and transported in hydrogen – after using solar energy to split water in fuel cells. If the comparatively modest level of solar installation that Wheeler and Ummel propose were to begin in 2010, the total power delivery del ivery by 2020 could be 55 terawatt hours per year – enough to meet the household electricity

demand of 35 million people. This is clearly not enough to provide power for our future futur e 9 billion, but improving efficiency would reduce energy consumption. And a global solar belt would be far larger than the one Wheeler and Ummel visualise. Nuclear, wind and hydropower could supplement output, with additional power from geothermal and offshore wind sources. Each high-rise community housing block could also have its own combined heat and power generator, running on sustainable sources, to supply most household energy. If we use land, energy, food and water efficiently, our population has a chance of  surviving – provided pr ovided we have the time and willingness to adapt. “I’m optimistic that we can reduce catastrophic loss of life and reduce the most severe impacts,” says Peter Falloon, a climate impacts specialist at the Hadley Centre. “I think there’s enough knowledge now, and if it’s used sensibly we could adapt to the climate change that we’re already

committed to for the next 30 or 40 4 0 years.” This really would be survival, though, in a world that few would choose to live. Large chunks of Earth’s biodiversity would vanish because species won’t be able to adapt quickly enough to higher temperatures, lack of water, loss of ecosystems, or because starving humans had eaten them. “You “You can forget lions and tigers: if it moves we’ll have eaten it,” says Lovelock. “People will be desperate.” Still, if we should find fi nd ourselves in such a state you can bet we’ we’d d be working our hardest to get that green and pleasant world back, and to prevent matters getting even worse. This would involve trying to limit the effects climate feedback mechanisms and restoring natural carbon sequestration by reinstating tropical forest. “Our survival would very much depend on how well we were able to draw down CO2 to 280 parts per million,” Schellnhuber says. Many scientists think replanting the forests would be impossible above a certain temperature, but it may be possible to reforest areas known as “land-atmosphere hotspots”, hot spots”, where even even small numbers of trees can change the local climate enough to increase rainfall and allow forests to grow. Ascension Island, a remote outpost buffeted by trade winds in the mid-Atlantic, may be a blueprint for this type of bioengineering. Until people arrived in the 17th century, vegetation was limited to just 25 scrubby species. But plantings by British servicemen posted there produced a verdant cloud forest. “It shows that if you have rainfall, forest can grow within a century,” says ecologist David Wilkinson of  Liverpool John Moores University in the UK, who studied the phenomenon. Even so, the most terrifying prospect of a world warmed by 4 °C is that it may be impossible to return to anything resembling today’s varied and abundant Earth. Worse still, most models agree that once there is a 4 °C rise, the juggernaut of warming will be unstoppable, and humanity’s fate more uncertain than ever. “I would like to be optimistic optimis tic that we’ll survive, but I’ve got no good reason r eason to be,” says Crutzen. “In order to be b e safe, we would have to reduce our carbon emissions by 70 per cent by 2015. We are currently putting in 3 per cent more each year. year.”” ■ Gaia Vince is a freelance science writer who is travelling the world. www.wanderinggaia.com To find out what will be left to harvest from the sea in the warmer world of the future, grab a copy of next week’s New Scientist . On sale 5 March. 28 February 2009 | NewScientist | 33

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Rise of the robogeeks Forget the likes o Terminator and Wall·E – the frst intelligent robot to stalk this earth could be seriously square, says Michae Michaell Brooks 34 | NewScientist | 28 February 2009

”Human brains don’t work by magic, so whatever it is they do should be doable by machine” primary aim, outlined in the journal Artifical p2015), is to use such a  Intelligence (vol 172, p2015), machine to improve our understanding of  where our mathematical ability comes from. Nevertheless, it is possible that such a robot could take us beyond what mathematicians have achieved so far. Forget robot vacuum cleaners and android waitresses; we’re talking about a machine that could spawn a race r ace of  cyber-nerds capable of creating entirely entir ely new forms of mathematics. The field of artificial intelligence has promised much before, of course. Early researchers thought it might open a fast-track to understanding consciousness, and there were claims that artificially intelligent computers and robots would change the world. The truth has been more prosaic. pro saic. AI has done some clever things, such as give us great chess players and voice recognition software, but it hasn’t delivered a revolution. But when it comes to mathematics, we can’t rule one out yet, says Alison Pease, Pease , who researches the philosophy of mathematics at the University of Edinburgh, UK. Pease teaches computers to do mathematics using AI programs, and thinks a computer really could astonish its programmer with a new mathematical insight. “Ours hasn’t yet, but there is no reason why one shouldn’t in the future,” she says. The first concrete step towards this N December, philosopher and artificial scenario came with a program written by intelligence expert Aaron Sloman Simon Colton, now at Imperial College announced his intention to create nothing London. The program was named HR, HR, in less than a robot mathematician. He reckons honour of the mathematicians Godfrey he has identified a key component of how Harold Hardy and Srinivasa Ramanujan. It humans develop mathematical talent. If he’s looked for “interesting” sequences of numbers right, it should be possible to program a ( New 13).  New Scientist, 24 February 2001, p 13). machine to be as good as us at mathematics, Some of HR’s discoveries have even been and possibly better. published – and HR, rather than Colton, This is no mad quest, insists Sloman, of the got the credit. Though they might not look l ook University of Birmingham in the UK. “Human like cutting-edge advances, they could yet brains don’t work by magic, so s o whatever it is prove important. “I always refer to HR’s they do should be doable in suitably designed work in number theory as recreational machines,” he says. mathematics, but things that look insignificant Sloman’s creature is not meant to be a can end up being hugely significant and mathematical genius capable of advancing the interesting,” Colton says. frontiers of mathematical knowledge: his Pease and her colleagues Alan Smaille

I

and Markus Guhe have recently taken things further. In their Edinburgh computing laboratory they have been running virtual mathematics conferences, populated entirely by digital mathematicians (see “Reinventing the conjecture”, page 36). 36 ). So where might that lead? All the way to significant new mathematics, Sloman hopes. His idea is that our key mathematical capabilities are formed in childhood. So rather than engineering a fully fledged mathematician’s brain, Sloman thinks we should build a robot with a child-like brain and let it grow into its mathematical mathematica l destiny. There’s just one problem. How do we know which of our childhood capabilities equip us for a life of juggling numbers? Sloman is busy gathering gather ing clues. The answer, he reckons, lies in the spatial awareness skills that children must acquire in order to negotiate their world: skills such as knowing that a toy train pushed into a tunnel will come out the other side. Or that a jigsaw puzzle p uzzle piece fits its gap only when correctly oriented. Or that the number of toys on the sofa does not depend on the order in which you count them.

From the minds of babes You might be surprised to t o learn, for instance, that you grasped the topological concept called “the transitivity of o f containment” when you were still a toddler. Stacking cups, one inside the other, you learned that the small cup would fit not only in the medium-sized cup, but also inside the big one. Transitivity of containment, like other geometrical and topological concepts, is learned through experience. “There are hundreds, if not thousands more examples of  things a child learns empirically, that are later seen to be theorems in topology, geometry and arithmetic,” Sloman says. At some point, children make that jump for themselves. As toddlers, we soon translate our experiences into general theorems which we use to make predictions. Take the train-through-a-tunnel example. By repeated experiences like this, toddlers > 28 February 2009 | NewScientist | 35

learn the basic properties of rigid rods. That’s why why a 3-year-old carrying a long l ong broom handle can negotiate a narrow corridor, turn a corner at the end without getting t he broom handle caught in the vertical bars of a stair-gate, then make adjustments so that t hat the handle will go through the next doorway. do orway. “There is a switch from learning empirically to realising realisi ng it has ‘simply got to be like that’,” Sloman says. And here is the key to the emergence of the mathematical mind. “The mechanisms that make that possible in a child are related to what makes it possible for them to go on to become a mathematician,” mathematici an,” Sloman says. “A lot of abstract maths has its roots in our ability to think about space and time, processes, and interactions between processes and structures. structures.”” Sloman has gone back to basics, to watch how children learn to navigate the world around them. He is building buildi ng an archive of  observations of children performing pseudo-mathematical tasks. These navigational and object manipulation skills –

or at least the ability to acquire them quickly – must be encoded in the genome, Sloman reckons. And that means they could be encoded in a machine. Sloman is still a long way from designing his robot toddler. Once he has catalogued the abilities of children at various stages of  development, he still has to work out how to understand the mathematical implications of  those abilities, then represent them in some form of computer code. “Information needs to be encoded in some form in order to be usable,” he says. The gargantuan scale of the task means his aims are necessarily modest: at this stage he is simply trying tr ying to show a link between spatial manipulations and the basics of mathematics. Anything more would be a bonus. But just how big could that bonus be? Could a robot mathematician really do something interesting? “In principle, principl e, yes, absolutely,” Pease says. But, she adds, the story-so-far tempers her optimism. “Of all the scientific and mathematical discovery programs I’ve

Reinventing Reinv enting the conjecture The traditional view of mathematics sees it as a set of some eternally existing rules that describe the universe. Doing maths involves exploring this abstract, ethereal domain. Though appealing to many, this notion of mathematicians as intrepid explorers is nothing more than a romantic myth, according to Alison Pease of the University of Edinburgh, UK. “Maths is not discovery,” she says. “It’s a thing that we invent.” It is something that her computers can invent too, she insists. Pease runs an AI program called HRL, HRL, which puts togeth together er “agents” in a student-teacher relationship. The students are programmed to take some input information, make inferences from it and try to assess just how “interesting” those inferences are. If sufficiently interesting, the teacher teach er gets involved, calling a group brainstorm designed to develop the ideas further. One of HRL’s early successes was the independent invention of a mathematical proposition called Goldbach’s conjecture. One of the students was given the concept of integers and divisors, and

36 | NewScientist | 28 February 2009

instructed to use these to play around with the integers 1 to 10, looking for interesting relationships. A second student had the same concep concepts ts and instructions, but played with the integers 11 to 20. Student two generated two new concepts: “even numbers” and “the sum of two primes”. Then it generated a conjecture: that all even numbers can be expressed as the sum of two primes. It thought this was interesting, and sent its work to the teacher to be placed on the agenda for discussion. The response was positive. “The teacher sent a request for modifications to this conjecture, and student one found the counterexample,” Pease says. That counterexample is the number 2: the conjecture was modified to “all even numbers except 2 are the sum of two primes”. The fact that Christian Goldbach came up with this still unproven conjecture in 1742 makes it a little less impressive, but the point is made. Even if computers are a few centuries behind, it seems that machines really can do what human mathematicians mathematic ians do.

looked at, nothing has yet made a big discovery.”” At the very least, she discovery. s he says, that means there is a long way to go. Colton thinks there is every reason to believe computers could produce something interesting to mathematicians. “Software is already producing theorems of o f value to maths,” he points out. “Not of huge value, I admit – but then the average student or mathematician isn’t producing anything of  huge value either.” ei ther.” He and his team are convinced that computers can be genuinely creative. “Creativity is a very loaded word: people like to think it’s a uniquely human attribute,” attr ibute,” he says. “The fact is, computers doing maths are more likely to be creative than, say, an undergraduate student, in many ways.” Others are sceptical scepti cal of this view. Computers are a useful tool, says s ays Rafael Núñez an expert on mathematical cognition at the University of California, San S an Diego, but the sense that computers can invent mathematics is an illusion. Though it looks like we can make progress by programming machines to do mathematics, he reckons there can be nothing in these machines that isn’t pre-ordained by human mathematical concepts. “For me, it’s like computing the decimal places of pi,” Núñez says. “Once we have decided what the right rules are, we’re just using the computer to crunch numbers.” Sloman thinks Núñez’s view is too narrow. He points to “evolutionary algorithms” as a reason for optimism. This innovation allows a computer to evolve its own programs by producing lots of them, testing them against a goal criteria, and then selecting and “interbreeding” the best ones. It has allowed computers do things that nobody programmed them to do. “In some cases no human even knows how they do what they do,” Sloman says. Aerospace and automobile designers have been using evolutionary algorithms since the late 1980s to optimise aircraft parts and streamline their designs. Even city traders are using them to buy and sell shares ( New Scientist, 28 July 2007, p 26). 26). Evolution has a few million years head start on us in developing brilliant mathematicians, of course, but at least we’re now in the ra ce. “Our big discovery would be how do we do mathematics, rather than how do we write a program that can generate really real ly new mathematics,” says Pease. “But hopefully one would lead on from fr om the other.” ■ Michael Brooks is writer based in Lewes, UK, and author o 13 Things That Don’t Make Sense  (Proile)

Why do people die that way? A grand theory of suicide promises to answer this question once and for all, says Robert Pool

F

OR a few months in late 2006 and early 2007, the woman who called herself  kristi4 was one of the best-known members of the pro-anorexia community. As the administrator of a blog on LiveJournal.com, she dispensed advice, encouraged others and wrote candidly about her own struggles. Then, late one Friday night, after a series of entries describing what she was planning to do, kristi4 killed herself with an overdose of prescription sleeping pills, muscle relaxants and painkillers. Her death was just one tragic data point in one of the most striking statistics in all of psychology. It has long been known that anorexia has the highest death deat h rate of any mental illness: one o ne out of every five people with anorexia eventually die of causes related to the disease. disea se. What has only now been recognised, however, is that a huge number of those deaths are from suicide rather than starvation. Someone Someo ne who develops anorexia is 50 to 60 times more likely to kill themselves than people in the

1

million Approximate number of suicides worldwide each year

general population. No other group has a suicide rate anywhere near as high ( Archives of  General Psychiatry, vol 60, p 179). Recently, psychologists have tried to explain why anorexia and suicide are so intimately connected, something which is helping to answer the wider question questi on of why anyone anyone would commit suicide. If this explanation holds up, it will give psychiatrists psychiatris ts a new tool for screening patients and determining which of them are most likely to kill themselves, perhaps saving lives. Suicide has always been a conundrum for psychologists and other researchers interested in human behaviour. Self-preservation is one of the strongest human instincts, so s o the drive to commit suicide must be even more powerful. But what causes it? A century ago, both the sociologist Emile Durkheim and the psychoanalyst Sigmund Freud came up with sweeping explanations. Durkheim, not surprisingly, saw the roots of suicide in social factors, such as a failure to integrate into society, while Freud rooted his explanation in instinctual drives, particularly what he called the death instinct. More recent explanations have tended to focus on factors such as depression, hopelessness and emotional pain, but none of them have had much success in answering ans wering the fundamental question about suicide: why do some people kill themselves while others in seemingly identical circumstances do not? Some progress has been made by crunching large amounts of data on suicide, says Harvard University psychologist Matthew Nock, who studies suicide and selfharm. Researchers have learned, for example, that suicide rates are rising and now account for 1.5 per cent of all deaths worldwide. worldwi de. > 28 February 2009 | NewScientist | 37

40 Every

seconds somebody dies by suicide Suicide is the second leading leadi ng cause of death among people aged 15 to 24, after vehicle accidents. Women are more likely than men to attempt suicide, while men are much more likely to succeed. Most people who commit suicide suici de have a mental disorder – anorexia, major depressive disorder, bipolar disorder, schizophrenia and borderline personality disorder are the most common, but an elevated suicide risk is part and parcel of many of the others, too. People who kill themselves also generally feel deeply deep ly depressed and hopeless at the time. What the statistics do not tell us – and what psychologists most want to know – is exactly which people are most at risk. ris k. The vast majority of depressed, hopeless people do not commit suicide, so why do some do it? In 2005, psychologist Thomas Joiner, a suicide specialist at Florida State University in Tallahassee whose own father committed suicide, set out to answer that question. By studying suicide statistics and paying particular attention to the groups with above average rates, Joiner believes he has found a common thread others have missed. “It was the first grand theory of suicide in quite a while,” says Nock. In essence, Joiner proposed that people who kill themselves must meet two sets of  conditions on top of feeling depressed and 38 | NewScientist | 28 February 2009

hopeless. First, they must have a serious desire to die. This usually comes about when peopl e feel they are an intolerable burden on others, while also feeling isolated from people who might provide a sense of belonging. Second, and most important, people who succeed in killing themselves must be capable of doing the deed. This may sound obvious, but until Joiner pointed it out, no one had tried to figure out why some people are able abl e to go through with it when most are not. No matter how seriously you want to die, Joiner says, it is not an easy eas y thing to do.

The self-preservation instinct is too strong. There are two ways people who want to die develop the ability to override the selfpreservation instinct, Joiner argues. One is by working up to it. In many cases a first s uicide attempt is tentative, with shallow cuts or a mild overdose. It is only after multiple attempts that the actions are fatal. The other is to become accustomed to painful or scary experiences. Soldiers and police who have been shot at or seen their colleagues injured or killed are known to become inured to the idea of their own death. d eath. Both groups also have a higher-than-normal suicide rate. Similarly, doctors and surgeons who witness pain, injury and death are more likely to be able to contemplate it for themselves – the suicide rate for doctors is significantly higher than for the general population. Joiner describes this as a “steeliness” in the face of things that would intimidate most people. Another group that displays steeliness are people with anorexia. Joiner had noted their heightened suicide rate in his original work, Why people die by suicide (Harvard University Press, 2005), but it wasn’t until later that he grasped the importance of the connection. That realisation began to dawn in 2006, during a seminar in i n which two of Joiner’s graduate students, Jill Holm-Denoma and Tracy Witte, were listening to him describe the risk of suicide among people with anorexia. Witte observed that the high suicide rate rat e had two possible explanations. Perhaps people with anorexia were no more likely li kely to attempt suicide than people with other mental disorders, but the anorexia had so weakened their bodies that their suicide attempts were more likely to succeed. Alternatively Alter natively,, perhaps anorexia had so inured them to pain p ain that

Global tragedy While some countries have a higher suicide rate than others, worldwide the rate has increased markedly since 1950 30 25

>13 6.5 - 12

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MALE

20 15 10

FEMALE 5

28 February 2009 | NewScientist | 41

about 100 milliwatts per square metre, the latest version generates over 3 watts per square metre, close to their target o 5 watts. Skilhagen reckons these membranes are now eicient enough to be worth testing beyond the lab, and in the next ew months the company plans to turn on the world’s irst prototype PRO plant at the Södra Cell paper pulp actory in Tote, alongside a ford f ord 60 kilometres rom Oslo.

it should be possible to pipe in the resh water using gravity alone. Build the power plant underground or on the river bed and gravity will also bring in the saltwater, says Skilhagen. The Tote plant will generate about 4 kilowatts, though a ith will be used or pumping the water. The rest – just over 3 kilowatts – is i s only enough to power a couple o kettles, but Statkrat hopes to construct a large scale salinity power plant by around

”Blue Energy could provide up to 7 per cent of global energy needs by exploiting around half the flow in the world’s largest rivers” The prototype will provide crucial experience in scaling up the system. syst em. The new plant its inside a room no bigger than a tennis court. “In the lab, our membrane had the ootprint o a coee cup. At Tote we will be using 2000 square metres metr es o the stu,” says Holt. A ull-scale plant will need millions o  square metres o membrane, so maximising the surace area or exchange is crucial, he says. The team is testing two designs. desi gns. In the irst, a long membrane tube is rolled up lengthways into a spiral something like a Swiss roll. Fresh water is pumped through the tube, while saltwater is pumped around the t he tube on the outside. Each spiral roll is less than 1 millimetre in diameter, and hundreds are arranged in parallel inside a pipe about 20 centimetres across. In the alternative design, the membrane is made into straight tubes which run through a tank o saltwater. Fresh water is pumped along the membrane tubes.

Help from gravity As well as inding the optimal optima l way to pack the membranes together, the researchers must work out how to prevent the delicate pores rom clogging with silt and algae a lgae in the water. They are looking at an anti-ouling coating coat ing to put on the membrane, and experimenting with reversing the low periodically to lush silt out, says Holt. The other challenge will be to minimise the energy used to bring the water into the pl ant. Lab tests show a ith o the electricity generated was expended on pumping the water in. However, many o Norway’s rivers drop steeply rom the mountains, so in uture 42 | NewScientist | 28 February 2009

2015. This will be about the size o a ootball stadium, contain 5 million square metres o  membrane and generate about 25 megawatts o electricity, they say, incorporating a new membrane and eiciencies o scale. It should power more than 15,000 households. Statkrat calculates that salinity power could eventually provide Norway with up to 12 terrawatt-hours o electricity annually, annually, roughly 10 per cent o o  the country’s consumption. “We estimate the global potential to be 1600 to 1700 terrawatt-hours annually,” says Skilhagen, about ab out 1 per cent o  the world’s annual energy needs. This would mean using about hal o the resh water lowing through every large estuary. There is some scepticism that Statkrat’s technology can be rolled out globally. gl obally. Norwegian rivers are relatively clear o mud and silt, says Veerman. “In other parts o the world such as the Netherlands and the UK there is lots o silt si lt and bacteria in the rivers. r ivers.”” The cost o cleaning up this water makes PRO a non-starter, he says. So Veerman and his colleagues at Wetsus have devised a rival system – a salt-based salt-ba sed battery. Dubbed Blue Energy, Energy, it generates electricity by moving ions rather than water molecules across membranes. Their membranes are along the same lines as those used in kidney dialysis machines. In act, their system requires two kinds o membrane – one permeable to positive ions, the other to negative ions. Both are impermeable to water. Typical sea water contains about 35 grams o salt per litre, so compared with resh water it is packed with positively charged sodium ions and negatively charged chloride ions.

The team placed alternating layers o their thei r two membranes in a stack to create separate chambers. When resh water and saltwater lows simultaneously across alternate chambers, chloride ions low spontaneously rom the saltwater through one membrane into the resh water, while sodium ions low through the other membrane in the opposite direction (see diagram, page 41). This movement o ions generates a potential dierence between a pair o electrodes, placed at either end o the cell. Veerman and his colleagues have already switched on a small prototype Blue Energy generator in their lab. lab . Though it only produces 20 watts o power, this convinced Pieter Hack, director o Dutch company Magneto, to orm a new company called Redstack, which will commercialise the technology. Now Redstack and Wetsus are collaborating on a pilot project, at a salt mine in Harlingen in the northern Netherlands. Salty waste water rom the mine and resh water rom the local loca l river are piped into the pilot plant, with each pipe eeding the rows o salt or resh r esh water channels inside the salt batteries. The unit – the size o three washing machines – is due to be switched on in weeks, and should pr oduce several kilowatts o power. Unlike Statkrat’s Statkr at’s Tote plant, this one isn’t linked to the electricity grid, but will help the researchers assess how Blue Energy can be scaled scal ed up. Membrane design is still an issue. The water-low rate must also be optimised. But since only ions cross the membrane, there is less mass lowing across the membrane than with their rival’s technology, and so silting

A tenth o the Amazon’s low could provide 50 gigawatts o electricity

Global maximum Salinity power generators could provide several thousand terrawatt-hours o electricity annually, supplying up to 40 per cent o the world’s electricity demand

YENISEI

MACKENZIE

44 gigawatts

23 gigawatts

problems are reduced, r educed, Veerman Veerman says. Veerman and his colleagues calculate that i  all the rivers o suicient size in the Netherlands were utilised, Blue Energy could provide as much as 75 per cent o the country’s electricity needs. By exploiting around hal o  the water lowing in the world’s largest rivers, they estimate that Blue Energy could provide up to 7 per cent o the world’s energy needs. Skilhagen thinks this igure is optimistic. “They haven’t accounted or the seasonal variations in river low, and environmental considerations.” considerations .” In theory, the Rhine can deliver 5 gigawatts o electricity. In practice, Skilhagen says, it would be impossible to block or divert the river’s entire low without doing serious environmental and economic damage. Yet Veerman Veerman estimates that t hat using around oneith o its low would be acceptable, providing around 7000 gigawatt-hours o electricity annually through Blue Energy.

RHINE 5 gigawatts

YANGTZE

MISSISSIPPI/MISSOURI

73 gigawatts

NILE

37 gigawatts

11 gigawatts

GANGES 32 gigawatts

AMAZON

MEKONG

500 gigawatts –

37 gigawatts

the equivalent o about 100 large power stations

MEGHNA (Bay o Bengal) CONGO

91 gigawatts

96 gigawatts

MURRAY/DARLING 2 gigawatts

Maximum theoretical output (assumes every plant generates 2 megawatts

per cubic metre o river water, and that the entire river fow is utilised)

us to build this prototype and ensure that it has minimal impact i mpact on the environment.” Both teams aim to learn these lessons Keep it clean quickly; though outwardly complimentary What o other impacts on the environment? about each other’s work, there is a clear The process generates brackish water, but this element o competition. Both technologies are could simply be pumped or channelled into i nto at a similar stage and the irst to prove their the sea. And each plant requires pipelines to design can be proitable without damaging collect and discharge water, as well as pylons the environment could have a serious to carry electricity to the grid. Large rivers advantage in the marketplace. oten have industrial ports where they meet River estuaries are not the only place pl ace where the coast and plants could be built in such salinity power can be set to t o work. Power could areas, says Skilhagen. Skil hagen. They already have much be generated at desalination plants using o the necessary inrastructure, inras tructure, too. “I’d be letover brine, or with waste brine rom surprised i there are no environmental industrial processes or salt mines. The Dutch problems, but we are not aware o any right team’s master plan, though, is to use the now,” he says. “This is why it is important or Asluitdijk dam which separates the Ijsselmeer rom the North Sea in the central Netherlands. The IJsselmeer is the largest lake in western Europe, covering an area o 1100 square kilometres. Fed by the river IJssel, its level rises by around 4 centimetres each ea ch day. This is insuicient or hydroelectric power, and the excess is currently emptied into the Nort h Sea. However, the sluice gates on the Asluitdijk dam are perect or eeding water past ionic membranes in a salinity power plant, says Veerman. This could create perhaps hundreds o megawatts or short periods, at times o  peak demand. “We could use this lake as an     C     F     S     G     / energy buer, in combination with wind     A     S     A energy,” says Veerman. Veerman. The Dutch team are     N  ,     S     I     D applying or permits to begin this project.     O     M  ,     S Compared to conventional energy     E     R     T     I     O generators, the capital cost o a salinity power     L     C     S     E plant is high, but likely to drop signiicantly     D     S     E once the technology is proven. Hack estimates     U     Q     C     A that it would cost over $600 million to     J

construct a 200-megawatt salinity power plant covering the area o two soccer pitches pi tches at the Asluitdijk dam, and that this plant pl ant would produce electricity at a retail cost o $90 per megawatt-hour. Statkrat won’t reveal detailed igures, but are aiming to produce electricity at a retail price pri ce o between $65 and $125 per megawatt hour by 2015. By comparison, modern ossil-uel power stations churn out electricity at a cost o about $50 per MWh. Roelo Schuiling, a geoengineer at Utrecht University in the Netherlands, believes beli eves that both types o salinity power projects are easible and could play a valuable global role. “I realised, it is more dependable than wind energy and could have a big impact on our energy sources,” he says. For example, a typical wind turbine is reckoned to generate electricity or an average o 3500 hours each year. A salinity power plant, on the other hand, could operate close to ull capacity or more than 7000 hours a year. Will salinity power ever pulse down the power lines? By May this year, when Statkrat licks the switch at their pilot plant, the technology’s true potential should become clearer. “We don’t claim that salinity power will be the global energy solution,” says Skilhagen, “but it could play an important role, and ensure that we hand over a better world to our children.” chi ldren.” Unortunately, Loeb won’t be there to witness the event: he died in December 2008, aged 92. “He had a lot o interest in our work until his last days, and his wie still ollows our eorts,” says Skilhagen. ■ Kate Ravilious is a science writer based in York, UK 28 February 2009 | NewScientist | 43

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BOOKS & ARTS

Say hello to the chickenosaurus Can we rewind evolution, turning the humble chicken into a dinosaur? of an older embryo before it turned into a stunted pygostyle. The experiment didn’t work, a failure that points to the tremendous complexity of the development process. We don’t yet know how to coax out a chicken’s inner dinosaur, but for Horner, it’s a worthwhile quest. Horner’s dream is to walk on stage on The Oprah Winfrey Show with chickenosaurus following him on a leash, but b ut he wants more

How to Build a Dinosaur: Extinction doesn’t have to be forever 

by Jack Horner and James Gorman, Dutton, $25.95 Reviewed by Jeff Hecht

JACK HORNER wants to raise the dead by growing a dinosaur from a chicken embryo. The publisher calls his idea “astonishing new science that trumps science fiction”. Has palaeontologist Horner’s stint as a consultant on

“Horner proposes altering gene regulation so the chicken embryo would grow a long dinosaur tail”

the Jurassic Park films infected him

with some science-fictional virus? Is chickenosaurus his bid to create a new monster-movie franchise? Fortunately, it’s “no” to both questions. In How to Build a  Dinosaur Horner is at his best: provocative yet firmly grounded in science. I doubt he’ he’d d mind hitting the bestseller list, but his goal is to make people think about how evolution works, and by extension, about our own origins. Science holds out some hope for cloning ancient DNA and resurrecting the victims of recent extinctions,, from dodos and moas extinctions to mammoths and woolly rhinos. But for dinosaurs, it doesn’t look promising. Horner’s former student Mary Schweitzer, for example, has extracted traces of  protein and possibly soft tissue from the extremely well-preserved leg bone of a Tyrannosaurus rex  that died more than 65 million years ago. DNA is far less stable than protein, so if the protein was scarce, Horner sees no chance that enough DNA survives to clone the extinct giants. So much for Jurassic Park. Happily, Horner thinks there’s 44 | NewScientist | 28 February 2009

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than fame. A dino-chicken, he writes, “would be shockingly vivid evidence of the reality of  evolution… The creature would be its own sound and vision-bite” visio n-bite”.. It wouldn’t be the first experiment in evolution – we live among uncontrolled examples including microbial response to antibiotics and insect resistance to pesticides – but it would be the first rewinding of evolution, the first time we could watch it happening in reverse. Linking the most charismatic of  fossils with the humble barnyard ba rnyard chicken would make a great scientific story. It would show how molecular changes bring about the large-scale differences in form seen throughout the fossil record. It would teach us about birds, dinosaurs and evolution. Co-authored by James Gorman, Gorman, deputy science editor of The The New  New York Times, this book makes for a good read, whether or not a chickenosaurus ever hatches. ■

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reveals that two sets of genes are involved, one controlling the expression of the other. There are a different way to build dinosaurs, the genes to build tail bones plus and it doesn’t involv i nvolvee finding any additional genes to transform the tail bone into other structures. fossil DNA. He wants to alter the embryological development of  Crucially, evolution most often affects the latter “control” genes. chickens, which are living That led Horner to propose descendants of dinosaurs. dinosaurs . His idea comes from the fertile field altering the chicken embryo so of “evo-devo”, “evo-devo”, which focuses on that it would grow a long tail, like those seen in dinosaurs or in how evolution affects the way animals develop from fertilised  Archaeopteryx , the earliest known eggs. Look closely at a developing bird, as well as other ancestral traits such as claws and teeth. embryo and you can see some With Horner’s encouragement, ancestral forms briefly appear. Birds, for example, start to Hans Larsson of McGill University in Montreal, Canada, thought he develop tails, then convert the might be able to grow a would-be-tail into a pygostyle, pygostyle, a bony lump at the base of the spine dinosaurian tail on a chick by splicing the fast-growing tail tip  Jeff Hecht is a regular contributor to which holds the tail feathers. from a young embryo onto the tail New Scientist  Careful study of this process Every chicken has an inner dinosaur but coaxing it out is another matter

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Light of life This is what visible light from the sun looks like if you you split it into its constituent colours. But playing with a prism at home will not give you this high-resoluti h igh-resolution on masterpiece, which was created using a sophisticated spectrometer spectrometer fixed to the world’s largest solar telescope at the Kitt Peak National Observatory in Tucson, Arizona. The spectrometer splits light from the sun intotwo into two beams and sends them towards two mirrors, which bounce the light back to a detector where the beams recombine.

Via a complex mathematical technique, the resulting interference pattern appears as a spectacular solar spectrum, covering the entire range of visible light. What are the dark blobs in the image? These are known as Fraunhofer lines after German physicist Joseph von Fraunhofer, who first studied them in detail in 1814. They are caused by specific elements in the outer layers of the sun absorbing a characteristic wavelength of light – the missing wavelength showing up as a dark

line. This barcode-l barcode-like ike image tells us about the elements present in the sun. For instance, the broad dark patch in the red part of the t he spectrum (upper right) indicates the presence ofhydrogen of hydrogen and the two prominent lines in the yellow part are sodium. As well as helping us to study the chemical composition of stars, such spectra can also tell us about the atmosphere ofplanets orbiting other stars. Astronomers first collect the spectrum when the planet is behind its host star, then when the planet passes in front. Subtract the

first from the second, and you get the spectrum of the planet. If we find other Earth-like planets in a star’s habitable zone, astronomers can study their spectra to look for water vapour, oxygen or methane in the planet’s atmosphere – all tantalising hints of life elsewhere. Anil Ananthaswamy ■

You can find this image in Hidden Universe by Lars Lindberg  Lindberg  Christensen, Christen sen, RobertFosbury  and Robert Hurt, Wiley-VCH  $29.95/£16.99 

28 February 2009 | NewScientist | 45

BOOKS & ARTS

No more drink How one man went to extraordinary lengths to conquer his addiction

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The End of My Addiction by Olivier Ameisen, Farrar Farrar,, Straus and Giroux/ Giroux /

Piatkus,, $25/£11.99 Piatkus Reviewed by Clare Wilson

AS a cardiologi cardiologist, st, Olivier Ameisen was familiar with hospitals, but not being detained in a psychiatric ward. Being committed to a New York hospital after yet another drinking binge was one of the many low points in his sevenyear struggle with alcoholism. The End of My Addiction is the fascinating tale of how he found his own cure through a bout of  pharmacological trial and error. Standard drug treatments for alcoholism and endless AA meetings hadn’t helped Ameisen. He lost his job and his girlfriend, and in his forties had to move mo ve back home with his mother in France. Then he heard of a medicine called baclofen, baclofen, long46 | NewScientist | 28 February 2009

used safely as a muscle relaxant, which animal research and a few anecdotal reports from cocaine users suggested reduced drug cravings. While in France, he began self-prescribing and found that at the standard dose his cravings for alcohol lessened. Desperate for a complete cure, he upped his dose beyond the medical recommendation and found his cravings eliminated. He has been sober for five years. One person’s experience isn’t, of course, proof of a cure. For that you would need large randomised trials, though the results of one small 12-week trial were promising (The Lancet, vol 370, p 1915). 1915). But this engaging account does give interesting insights into the toll this disease can take and shows how, at least in this case, it was possible to fight back. It also explores the science behind baclofen’s possible mechanism of  action, and why it may be useful against other addictions.

Matter’s doppelgänger Antimatter by by Frank Close, Close,

Oxford University Press, £9.99/$19.95 Reviewed by Amanda Gefter

LIKE the universe in Alice’s looking glass, there exists a mirror world to our own – an antiworld built from antiparticles that congregate into antiatoms, antimolecules and possibly even antilife. This is the world of antimatter, antimatter, and there could be no better guide to its strange landscape than physicist Frank Close. Close. In this beautifully written book, Close elucidates the mysteries behind matter’s matter ’s doppelgänger – from its theoretical underpinnings, to its experimental triumphs, triumphs, and its practical applications, such as the use of antiparticles in brain imaging technology. Close explains how to tell if an alien civilisation is made of antimatter and why antimatter bombs remain science fiction, despite the US military’s interest in them. Ultimately, antimatter holds the secret to why there is any matter at all. This book will inspire a sense of awe in even the most seasoned readers of physics books.

tells a fascinating tale of an artifact that upends our estimation of  Classical technology. Ignored, misinterpreted and even fobbed off as “alien technology” technology ”, it has taken a century to fully recognise the extraordinary gearwork’s purpose in tracking planetary motion.. Amid the hazardous motion dives that raised it and the lives spent in painstaking research and professional jealousy, Decoding the Heavens conveys the wonder of a find one archaeologist hailed “as spectacular as if the opening of Tutankhamen’s tomb had revealed the decayed but recognisable parts of an internal combustion engine” engine”..

Come doomsday The Vanishing Face of Gaia by James

Lovelock, Allen Lane, £20 Reviewed by Andrew Robinson

THE financial crash may help sales of James Lovelock’s Lovelock ’s second volume on Gaia. If  it happened to the economy, why not to climate? climate? Both systems are “complex and nonlinear and can change suddenly and unexpectedly”, he writes. He lacks confidence in climate models with their smoothly rising curves of global temperature up to 2100, Heavens above and instead anticipates a sudden flip to a state 5°C as hot. Decoding the Heavens by by Jo Marchant Marchant,, Since it is too late to prevent p revent Da Capo Press, $25 this, we must think about how Reviewed by Paul Collins to adapt and act fast. The best TO THE untrained chapters concern survival eye, the first strategies, such as energy and analogue food options for the UK, which computer wasn’t will become a “lifeboat” for much to look at. environmental refugees. Retrieved from Published simultaneously, He a 1st century BC  Knew He Was Right , an authorised Greek shipwreck, biography of Lovelock by John the Antikythera mechanism Gribbin and Mary Gribbin, resembled “a green, flaky pastry”, pas try”, demonstrates well how Gaia albeit one with a filling of gears has overcome its main critics to inscribed with enigmatic become part of a distinguished lettering. Jo Marchant, a historical tradition of serious if  consultant for this magazine, controversial science.

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FEEDBACK

The paper is actually about fish, Ben tells us, and the vocalisations are of the low-frequency variety, variet y, making Bass a rare example of  double nominative determinism.

READER Laurel Daniel says she knows we have said we don’t want any more examples of nominative determinism, but she still thinks we might be interested in the convergence of name and talent demonstrated by Jolee Bacon, the Idaho woman who won first place in the Nez Perce County Fair hog-calling contest. A short trawl of a famous web search engine (FWSE) reveals that 2008 was the first year that women – not only Jolee Bacon of  Idaho (www.joleebacon.notlong. com) but also Doris Probst of  Illinois (www.dorisprobst. notlong.com) – started to beat men in these hog-calling contests, which involve squealing, oinking, snorting and generally making noises like a pig. We were pleased to learn this, and we were also pleased to be informed by Meredith Lloyd-

Evans that he recently came across the headline “Swine Vets Invited to Apply for Hogg Scholarship”. This was followed by the explanation: “The American Association of Swine Veterinarians Foundation is to offer the Hogg Scholarship, established to honour the memory of longtime AASV member and swine industry leader, Dr Alex Hogg.” Meredith tells us that this information was “gleaned in surprise” not from the FWSE but from www.thepigsite.com, www.thepigsite.com, which is a mine of information about all things swiney. Turning to something quite different, Ben Haller tells us of a paper in Science (vol 321, p 417) 417) entitled “Evolutionary origins for social vocalization in a vertebrate hindbrain-spinal compartment” one of whose authors is A. H. Bass.

“Philip Hole felt the message he received from Scottish Power was a bit back-to-front: “If you receive this email by mistake, please delete it then advise the sender immediately by reply email” 76 | NewScientist | 28 February 2009

THE latest unusual unit to join the Titanic (weight), the Wales (area), the Olympic swimming pool (volume), the African elephant (large size) and the Kylie Minogue (small size) is the kiloSteve (Steves), which was coined this month by Project Steve. Steve. In a parody of creationist lists of “scientists against evolution”, Project Steve has been gathering names of scientists in favour of evolution – as long as their name is Steve (or equivalent). The thousandth such Steve has now signed up, hence the kiloSteve. We are sure this new unit will be invaluable in enabling people to comprehend large quantities of Steves. It could also highlight a dangerous decline in their number. The current population of Steves in the US is 2924 kiloSteves (according to the 1990 census, and including Stevens, Stephens, Steves, Stephanies and Stefanies). But the

birth rate in 2005 was a mere 12.8 kiloSteves per year, far short of replacement level. This becomes more serious if you consider that when the census was taken, the US population density was a scant 304 nanoSteves per square metre. It is with sadness that we note in conclusion that while the Henry is a well established SI unit (measuring inductance), the Système International does not yet employ the Steve or its derived units. However,

stephanometrology is a young science so hope remains that it will soon be given proper recognition.

ON THE TV dinner that Hanne Pederson bought at a Sainsbury’s Sains bury’s supermarket was a guarantee saying: “We’re sure you’ll love this product. If you don’t, simply return for a full refund.” r efund.” Hanne points out that this offer implies they are not so sure the product will be loved after all, to which Feedback adds, delicately: “How pristine pristi ne does it have to be for them to accept a return?” “I did think of that as well,” says Hanne. “If you decide you don’t like the meal, it implies that you have eaten it already. In that case, there is only one way of returning it that I can think of, and it’s not going to go down well at the customer help desk.” des k.”

A PIECE of paper floats to the surface of our filing system from 2008, and we find Emily Ackerman telling us about an advertisement in the medical section of Woman & Home  magazine offering trips to a clinic in Bratislava for orthopaedic surgery: ”We are offering hip and knee replacements, keyhole surgery, replacement of any other limbs you might have a problem with.” Emily wonders which limbs they have in mind, how they are going to replace them, “and, er, what with?”

FINALLY, Sam Joyce-Farley FINALLY, Joyce-Farl ey was surprised and a little disturbed at the claim on his pack of Oberto Obert o dried beef jerky. jerky. The pack told him: “The meat contained herein… is derived from animals that received ante and postmortem inspection and were found sound and healthy.”

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Last words past and present, plus questions, at www.last-word.com

THE LAST WORD Double trouble Our daughter Aisling would like to know why we have evolved two bodily systems to excrete waste products. Why do we have to both poo and wee?

Strictly speaking, the question is misplaced. We do not “excrete” faeces because our bodies are long fleshy tubes which can be thought of as extremely elongated doughnuts. In a doughnut, one would not consider the hole to be “inside” the cake. Similarly, the tube from our mouth through our gut to our anus is technically technical ly “outside” our living body. The process of “excretion” is the passing of material from inside our bodies to the outside. Our kidneys excrete urine, our skin excretes sweat, our lungs excrete water and carbon dioxide, and the inside of our bowel tube excretes many things along its length to assist digestion, as well ■

bacteria. It has never actually been further: rather than having a inside our bodies. Apart from the distinct urinary system, insects bile and one or two other remnants rely on malpighian tubules in from our exocrine glands, it their digestive systems – cannot be regarded as excreta, outgrowths of the gut that perform the same filtration despite the common use of that word to describe it. function as our kidneys. Shaun Hug  Bryn Glover, Cracoe, North Yorkshire, UK   La Mirada, California, US

as disposing of waste products in our bile. The other excreta our bodies produce include tears, earwax, and various secretions associated with our reproductive processes. If young Aisling suffers (or is about to suffer) from spots, then these too are caused by excretions which have gone awry. aw ry. Our faeces, on the other hand, consist of undigested food and

The types of waste we excrete have two different origins. Faeces contains the leftover, indigestible portion of the food we eat, plus bile from the liver, which gives excrement its brown colour. Urine, on the other hand, is the result of blood filtration in the kidneys. Urine contains nitrogenous waste, primarily in the form of urea, which results from the metabolism of nucleic acids and proteins, separate from digestion. Furthermore, urine also contains water and solutes from the blood, and interstitial fluids – these are excreted to maintain water balance. Essentially, faeces are the result of  a coarse, large-scale process of the digestive system alone, whereas urine production occurs at a much finer scale, eliminating wastes produced by all the body’s cells. Our two excretory systems are obvious because b ecause we have a separate opening for each: the anus and the urethra. In other organisms, the distinction between the systems isn’t as obvious. Animals such as birds, reptiles, and amphibians possess a cloaca, cloaca, which serves as a common opening for both liquid and solid wastes. Insects blur the line li ne even

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“A human is an elongated doughnut: the tube from our mouth to our anus is outside our living body”

■

Smells fine to me After buying a spray-on deodorant, I got home and realised it was intended for women. Nevertheless, not wanting to waste money I used it anyway. Nothing untoward happened and I received no strange looks from colleagues or friends. So what are the differences between deodorants meant for men and those that are meant for women? How might using the “correct” deodorant for your sex work better than using one meant for the opposite sex, and what are the pitfalls of applying a deodorant intended for the opposite sex?

The primary function of all deodorants is to inhibit growth of  bacteria which feed on secretions from sweat glands. Deodorants are most often differentiated, if  at all, by strength. But sex sells, so we have men’s and women’s. They have only three differences: advertising, packaging, and fragrance. Remove fragrance and there are only two differences: advertising and packaging. Formulations for both sexes contain such things as flowers, herbs, spices, fruits and woods, and are judged as suitable entirely by personal and cultural taste. For example, one upscale new fragrance contains citruses, herbs, ylang-ylang, jasmine and tiare flowers, musk, tropical woods and coconut – and it’s for men. And many women buy men’s fragrances, because there is none of the social embarrassment that the reverse carries. A fascinating discussion about fragrance sales and attitudes is online onli ne at www. tinyurl.com/bnublk Toshi Knell  Nowra, New South Wales, Australi a ■

THIS WEEK’S QUESTIONS BAD SOAP

I found this forgotten bar of  soap after winter at my home in northern Sardinia. It had grown a coat of mould (pictured). What is the mould and how did it grow on soap, which is supposed to keep your hands clean?  Patrizia Figoli Turchetti  Bellaire, Texas, US

Do Polar Bears Bears Get Lonely? A brand new collection serious enquiry, brilliant insight and the hilariously unexpected Available from booksellers and at www.newscientist.com/ polarbears