If you're thinking
. ..
�what would a new resident mean for sterling?' contact us.
•
Financial spread betting provides a simple, tax-free· way to profit from rising and falling prices.
•
Take a position with IG Index on forex, commodities, shares, stock indices and more.
•
World leaders in financial spread betting for 35 years.
Find all you need to get started at igindex.co.uk or call 0800 195 3100. Spread betting can result in losses that exceed your initial deposit. 'Tax law can be changed or may differ depending on your personal circumstances.
CONTENTS
Volume 205 No 2752
NEWS 5
6 B
COVER STORY
EDITORIAL Scientific fingerprinting, at last
Relativity's final frontier
UPFRONT Overfishing and its effect on cookery, Artificial dark matter - probed
THISWEEK World shipping's inadvertent geoengineering
The search for
experiment poised to end, Putting science into
ripples in space
fingerprint evidence, Orange star will clip solar system, Did Neptune devour a super-Earth?
time approaches
Simple sketches that move the brain
its climax
12 INSIGHT What exactly are nuclear weapons for?
16 IN BRIEF Octopus lacks "personality", Gorilla play reveals theory of mind, Psychopathy is its own reward
Cover image Sam Chivers
19 TECHNOLOGY
Cybercrime for dummies, Sharpening translation tools, Round-the-corner radar
Future perfect
OPINION 24 LETTERS All about climate change, Sugar pills 26 Barefoot statistics Important things get left
out when government and big business are the
This man has
only ones funding statistics, says Ludi Simpson
been predicting
27 One minute with ... Brian Cox on fighting cuts
the future and
in physics, Tony Blair's theme tune and his love
getting it right
affair with T itan
for 30 years
2B Hippy icon to eco-pragmatist Why Stewart Brand thinks green ideology is flawed and
nuclear power and slums are good
FEATURES 30 Relativity's final frontier (see right)
34 It's a bug's death A smart new way to eliminate the pests that ruin crops while leaving their benign relatives unharmed
3B The brain broadcast Get enough of the right
brain cells to talk about the same thing, and out pops consciousness
8
Coming next week
42 The predictioneer (see right)
Weird moons
REGULARS 24 ENIGMA
46 BOOKS & ARTS
Reviews Taking a byte out of the universe,
Decoding Reality paints an intriguing picture of how quantum mechanics constructs the world,
47 Evolving ecosystems, Battery power rules, Navigating, naturally
56 FEEDBACK Dangerous fictions for kids 57 THE LASTWORD Salt assault
The shipping forecast Theworld's shipping lines are poised to implement pollution measures thatwill boost global warming
The solar system has more than 170 of them. We pick our top 10 Jared Diamond on the science of human history PLUS
4B JOBS & CAREERS USA
AUSTRALIA
RecruitmentAdvertising
TO SUBSCRIBE
Syndication
New York, NY 10010,
225 Wyman Street.
Tower 2, 475 Victoria Avenue.
Tel 781734 8770
Tel 888 822 3242
Tribune Media Services
Periodicals postage paid at New York, NY and other mailing
Waltham. MA 02451
Chatswood, NSW 2067
[email protected]
[email protected]
International
Tel 781 7348770
Tel +612 9422 2666
Permissions for reuse
An annual subscription in the USA
Tel 213 237 7987
offices. Postmaster: Send address
Fax720 356 9217
Fax +5129422 2533
Tel +442075111210
is $154-including delivery.
email
[email protected]
changes to New Scientist,
Marketing
An annual subscription in Canada
© 2010 Reed Business
po 80x 3805, Chesterfield, MO
Editorial .. media enquiries
Tel 781734 8778
is CAN$182 in cluding delivery,
Information Ltd, Engla nd,
53005-9953, USA,
Tel 415 908 3348
Tel 781734 8770
mar keting @new scientist.com
Fax 415 704 3125
[email protected]
UK
Enquiries
Lacon House, 84 Theobald's Road,
201 Mission Street. 26th Floor,
Sa n Fra ncisco, CA 94105
Regi stered at the Post Office
Canadian subscriptions distributed by RCS International, 12182 Belden
New Scientist ISSN No, 0262 4079
as a newspaper and printed in USA
For a full list of who's who at
Ct. Lr"onia, M148150.
is published weekly except forthe
by FryCommunications Inc,
Tel +44 (0) 20 7511 1202
new Scientist go to
Newsstand
last week in December by Reed
Mechanicsburg, PA 17055
[email protected]
newscientist,com/people
Distributed by Curtis Circulation
8usiness Information Ltd, England , Reed Business Infonmation, clo
London, WCIX 8NS
Display Advertising
Company, 730 River Road, New
Tel +44 (0)20 7611 1200
Tel 781 7348779
Milford, NJ 07646·3048
Schnell Publishing Co, Inc" 360 Park
Fax +44 (0)20 7611 1250
joe,
[email protected]
Tel 201634 7400
Avenue South, 12th Floor,
(]... IReed Business nformation
20 March 2010 I NewScientist 13
Making offshore wind viable is the engineering challenge of the decade. By 2020 we could create 70,000 jobs and when finished provide more than a quarter of the UK's electricity.
The Carbon Trust is bringing together the leaders in the industry, from energy companies to technology developers, to overcome the technical and economic challenges to make offshore wind happen.
Contact us to find out how we could help you open up new commercial opportunities.
carbontrust.co.uklcleverthinking
0800 085 2005
---
......
CARBON TRUST
Making business sense The Carbon Trust is funded by Government.
of climate change
EDITO RIAL
Fingerprints put forensics on trial The issues raised by fingerprint evidence go to the heart of what it means to be a scientist
same way that statistics are used to quantify the likelihood of a match when DNA evidence is presented in court (see page 10). This is a monumental shift, and one which could finally force examiners to give up the outdated notion that a crime scene print could only match a single individual to the exclusion of all others. The researchers involved - some of whom are fingerprint analysts themselves - should be applauded for their candid, sensible and scientific approach to fingerprint identification. In order for such tools to find practical applications within the courtroom, however, they will need to be validated by the analysts who will use them. We also need to be sure that the statistics this software produces are watertight, so as to avoid a repeat of the bitter squabbles that still haunt the use of DNA evidence.
IN THE 19th century, Mark Twain played a key role in popularising the then newfangled method of fingerprinting. "Every human being carries with him from his cradle to his grave certain physical marks which do not change their character, and by which he can always be identified - and that without shade of doubt or question," he wrote. Until recently, most of us believed that this meant a fingerprint match from a crime scene was proof of guilt. That impression has been cemented by their widespread use, by US "If they want to be called forensic immigration services, for instance. But in scientists they're going to have to make their work more scientific" recent years, several miscarriages of justice have highlighted how fingerprints can -and occaSionally do - finger the wrong person. The researchers also need to convince everyone who works with fingerprint Studies have also shown that fingerprint evidence - including agencies such as the analysts can come to different conclusions FBI -that such models won't undermine over whether two prints match, and even the same analyst may not make the same decision their roles. This will require the biggest shift about two prints every time. in thinking of alL Many fingerprint analysts are also waking Sometimes fingerprint analysts can up to the fact that if they want to be called feel under pressure from the court to come forensic scientists they're going to have to up with unequivocal results. So analysts make their work more scientific. need to ask themselves a question: would I treat the samples before me in a different This week, we report on some of the first moves in this direction, with the development way if they were unconnected with a court of software that is able to apply statistical case? For the sake of forensics, the answer weight to fingerprint evidence - in much the should always be no.•
The quest for the perfect pesticide PESTICIDES and genetically modified organisms are two things that environmentalists love to hate. There are certainly good reasons to hate conventional pesticides. Looming large among those are the harm they do to the humans exposed to them and the death of beneficial insects, fish and birds. Now, however, researchers are developing a new kind of insecticide, one that will only wipe out a target species (see page 34). The key is a method of gene silencing called RNA interference. There is every reason to think this approach will be safe. In many cases, the best way to "apply" RNAi will be to genetically modify plants, and there's the rub: many green organisations, along with the organic food movement, oppose all GM crops. They should reconsider. Plants modified to produce bacterial toxins appear to have cut conventional pesticide use. Plants containing RNAi-based pesticides should be even better and it may be hard for target pests to evolve resistance to them. They will be safer for the environment, farmers and consumers than conventional pesticides, too. Indeed, they will even be safer than the pesticides sometimes used by organic farmers, such as rotenone, a plant extract that has been linked to Parkinson's disease. For most farmers, after all, the choice is not between pesticides or no pesticides. It's between more or less harmful ones .•
Whafs hot on NewScientist.com BLOG Does the pill help women
to write a poem in "pilish", i n which the
ZOOLOGGER Pregnant males
reveal how emotiona Ily involved
live longer? Splashed over the
number of letters i n each word must
are pro-choice Who's the daddy?
a person is with a movie trailer or
news is the dramatic claim thatthe
follow the digits of pi
If we're talking about Gulf pipefish,
TV commercial
he's easy to spot: he's the one that's
contraceptive pill could be helping women live longer, But hang on, the
TECHNOLOGY Safety issues
pregnant We discover that these
research does not necessarily mean
loom as humanoid robots march
pipefish are capable of selective
that there are more pros than cons
nearer Engineers are building
a bortion, too
to taking the pill
smarter humanoid robots, capable of working or living i n close proximity
9 GALLERY Natural history
museums - photographers'
playgrounds What is it about the museums that seems to draw art
D
TECHNOLOGY Neuro-
photographers to them? We asked
marketing is ramping up
three to explain why in an online
MATHEMATICS Some tasty facts
to humans, But design tweaks
about pi To celebrate pi day on
such as sensitive skin, lighte r
Advertisers are increasingly turning
14 March, we present some lesser
limbs and the abi lity to read
to neuroscience to help guide how
known facts about the mathematical
human expressions are needed
they reach consumers, See video
For comment video and online
constant, and give you the chance
to ensure they a re safe
that shows how brainwaves can
debate, visit newscientist.com
gal lery of thei r work
20 March 2010 I NewScientist 1 5
UPFRONT
Cookbook threat to fish RARE is not only beautiful but tasty. A study of 122 years' of seafood recipes has shown that big. predatory fish like salmon and tuna have grown in prestige. even as overfishing has caused their populations to plummet. Phillip Levin and Aaron Dufault of the US government's Northwest Fisheries Science Center in Seattle examined 3092 seafood recipes from 105 cookbooks published in the Seattle region between 1885 and 2007. For each. they noted the species used and estimated its trophic level - a measure of how high in the food chain the species sits. For example. sharks have a trophic level of 4 or more. The team found that the average trophic level ofthe recipes rose from 2.92 to more than 3.4. indicating a
Victory for vaccines THE US government won't dole out cash to parents who claim that a preservative in vaccines triggered autism in their children. Several large-scale studies have failed to find a link between vaccines and autism. But that didn't stop parents from 5000 families who believe there is a link from seeking compensation under the National Vaccine Injury Compensation Program, created to help the small number of children who have severe allergic reactions to vaccines. On 12 March, the judges overseeing the scheme declared there was no proofthat the children's autism was caused by thimerosal (thiomersal outside "Anti-vaccine campaigners keep moving the goalposts. It is the hallmark of pseudoscience"
the US), a mercury-containing preservative used in some vaccines. The same court had already thrown out claims that thimerosal plus the measles6 1 NewScientist 1 20 March 2010
mumps-rubella vaccine causes autism. "The ruling supported the science," says Paul Offit ofthe Children's Hospital of Philadelphia in Pennsylvania. The families can appeal the decision, but it is unlikely to be reversed. This may not be the end of the anti-vaccine campaign, however. Campaigners have already started blaming the sheer number of vaccines a child receives, rather than a particular one or combination, for autism. "They keep moving the goalposts," says Offit. "It's the hallmark of pseudoscience."
Fake dark matter THE key to understanding dark matter is in our grasp -we've got something here on Earth that works just the same way. Materials called topological insulators can be used to mimic the dynamics of axions theoretical particles that could account for dark matter, say Shoucheng Zhang and colleagues at Stanford University, California. "They are an exact mathematical analogy," says Zhang. Magnetic fluctuations in the materials produce a field just like an axion
shift to larger. more predatory fish. The rise is large and potentially damaging: a 0.15 change in trophic level is enough to have an impact on ecosystems. Levin had expected the opposite trend. Intense fishing has depleted the stocks of many large fish and global catch is increasingly made up of smaller fish from lower trophic levels. He suggests it didn't work out that way because cookbooks reflect not what we eat but what we aspire to eat. Indeed. rarity may be partly responsible for the high status of fish like cod and tuna. Levin says. This could boost a demand that may stymie efforts to restore healthy fish populations (Fish and Fisheries, 001: 10.1111/j.1467-2979.2010.003SS.x).
field, his team found (Nature Physics, DOl: 10.1038/nphys1534). That means we could probe the effects of dark matter in the lab. For example, the polarisation of the cosmic background radiation left over from the big bang should depend on how it interacts with dark matter. Simply measuring light shone through a topological insulator could show what cosmic effects to expect. "It could tell us how to build better detectors," says Zhang. He presented the work this week at a meeting of the American Physical Society in Portland, Oregon.
9/11 health payout THE legal fight over the health risks posed by the giant dust plume that formed when the World Trade Center in New York City collapsed may come to an end before the scientific dust settles. The city's lawyers had challenged some of the claims that the cloud swirling around the wreckage damaged the health of rescue and clean-up workers. Now the city is offering a $657.5 million settlement, so the cases may
Fordaily news stories, visit www.NewScientist.com/news
never go to court. If the plaintiffs approve, the city will award payments according to the severity of a person's condition and their exposure to debris. However, we still don't know what was behind the adverse health effects, such as lung problems, stomach ailments and possibly cancer. Larger, high pH particles ofcement, glass and pulverised debris are the likely cause of respiratory problems, says Paul Lioy at Rutgers University in Piscataway, New Jersey. But the gases and particles mixed in novel ways, making it hard to pick out "smoking guns".
Arctic animal boom CONTRARY to popular belief, Arctic animals have done rather well over recent decades. The first analysis of a 40-year database of Arctic species reveals that populations grew bY16 per cent on average between 1970 and 2004. The Arctic Species Trend Index covers 35 per cent of all Arctic vertebrate species. The analysis, led by Louise McRae at the Zoological Society of London, shows several mammals have benefited from hunting bans. Populations of bowhead whales, for instance, have risen by about
60 SECONDS
3 per cent per year for 30 years. But the trend masks worrying recent declines. Warmer waters in the Bering Strait boosted the Bering Sea pollock between 1970 and 2003 by increasing plankton growth, but numbers have since "Populations of bowhead whales have risen by about 3 per cent per year for 30 years"
declined. The dark-bellied brent goose has also declined, after an initial recovery of numbers. The team says the recent declines could be linked to climate change.
Energy creep
Will the shuttle linger on?
SURVEYS of hundreds of UK households reveal that people who have made their houses more energy efficient are more likely to indulge in small excesses -turning up the heating, for example, or keeping it on for longer. Small excesses add up to large costs. The results of the studies seven of them in total -suggest that such energy creep could wipe out as much as half ofthe anticipated savings from making homes more energy efficient
THE demise of NASA's Constellation moon rockets is bringing faint hopes of a reprieve for the space shuttle. NASA's decades-old shuttle fleet
International Space Station without relying on foreign launchers. "If the space shuttle programme is terminated, Russia and China will be
has been headed for retirement since 2004, and only four more flights are scheduled. Now the White House's plan to scrap the Constellation
the only nations in the world with the capability to launch humans into space," says Texas senator Kay Bailey Hutchison, who introduced the first ofthe two bills this month. "This
(Building Research & Information,
vol 38, issue 1). "Some householders who install double-glazing, insulation and energy-efficient boilers end up using fuel at close to the old levels, often because they are more concerned about comfort than saving energy," says David Lomas of Loughborough University, UK. He was a lead member of the UK-government funded consortium which carried out the surveys. Lomas says the results question whether the government's target of reducing energy consumption in homes to 20 per cent of 19 9 0 levels by 2050 is achievable. Paul Stern of the US National Research Council agrees but emphasises that efficiency measures do save energy overalL
programme - a pairof rockets capable of taking astronauts back to the moon - has prompted renewed efforts to keep the shuttles running until new vehicles can replace them. Two bills have been introduced in the US Congress to keep the shuttle flying while NASA works to develop replacements. The hope is that a modest extension - involving just a couple offlights a year - could help retain jobs and maintain access to the
is unacceptable." An extension to shuttle flights may struggle to win approval. Safety has been a concern, but a bigger hurdle may be money. The cost of a modest programme could exceed $2 billion per year, according to agency officials. "Where that money comes from is the big question," shuttle programme manager John Shannon told reporters last week.
Painless painkillers Two genes that allow opium poppies to make morphine and codeine have been identified. Transferred into microbes, they could enable the painkillers to be made in vats, instead of having to be extracted from poppies. This would reduce the land needed to make the drugs and their cost, say researchers in Nature Chemical Biology
(001: 10.1038/nchembio.317).
Falcon to fly soon All nine engines ofthe SpaceX Falcon 9 rocket were successfully test-fired on 13 March, taking it a step closerto being ableto deliver cargo for NASA to the International Space Station. A test launch is scheduled formid-April.
Improving the IPCC The UN announced last weekthatthe InterAcademy Council- an umbrella organisation forthe world's science academies - will review the methods ofthe Intergovernmental Panel on Climate Change and recommend how the IPce can improve its methods in future. It will not reassess the conclusions of the IPCC's 2007 report.
Celebrity genome As an A-list actor, Glenn Close was already part of an elite club. Now she has entered an even more exclusive group by having herwholegenome sequenced. Close has a family history of bipolar disorder and schizophrenia, and is co-founder ofa non-profit body that raises awareness about mental illness. She hopes that whole genome sequencing will help unravel its genetic underpinnings.
Inflated ambition Would you wantto be the first to orbit Earth in an inflatable space station? Bigelow Aerospace of Las Vegas, Nevada, is advertising (bit.lyJ cBY39F) for astronauts to crew its proposed Sundancerspace habitat, which will use air pressure alone to keep its shape. The job description includes space walks and spacecraft engineeri ng.
20 March 2010 1 NewScientist 1 7
THIS WEEK
The hidden virtue of ships' pollution Emissions from shipping are a hazard to health, but till now they have been doing the planet a favour
diminish by as much as 90 per cent, and with them the resulting ENVIRONMENTAL paradoxes don't haze of sulphate particles. come much bigger. In July this year, That's where the problem lies. By shading the planet, the haze the world's shipping lines will begin to apply pollution-cutting partially masks the warming rules that will save tens of effects of greenhouse gases such thousands of lives a year. Yet as carbon dioxide also produced these very measures -which will by the world's fleet of 100,000 radically cut sulphur emissions ships. Almost a billion tonnes from ships- have a downside: they of CO2 are emitted annually by will also increase global warming. shipping, some 3 per cent ofthe global total, and it was originally When it meets next week, the planned that measures to reduce Marine Environment Protection these emissions would also be Committee of the International Maritime Organization (IMO), introduced at next week's meeting. Those plans are now on hold. the UN body that regulates world shipping, will not even As a result, the world is set to suffer a double warming effect be discussing setting limits on regulating the carbon emissions of from shipping, says Jan shipping. Yet it will confirm plans Fuglestvedt of the Centre for to slash the permitted sulphur International Climate and Environmental Research in content offuel oil burned by most ofthe world's ships. Sulphur Oslo, Norway: "one from CO2 dioxide (S02) emissions will and one from the reduction of Fred Pearce
8 1 NewScientist 1 20 March 2010
502" (Environmental Science & Technology, vol 43, p 9057). Shipping lags behind most other industries in tackling sulphur pollution. Emissions from power stations, road vehicles and other land-based sources have been reduced to very low levels both for health reasons and "Few policy issues are more complex than the effects of carbon and sulphur emissions from shipping"
to curb acid rain. But ships can still burn fuel containing 4.5 per cent sulphur; for European cars the limit is 0.001 per cent. Just 16 large ships could emit as much 502 as all the world's cars. Two years ago, the IMO agreed a plan to cut the emissions of 502 from the world's fleet. The plan, which comes into force in July,
will cut the maximum sulphur content of shipping fuel to 3.5 per cent in 2012 and 0.5 per cent by 2020. Special sulphur emission control areas around the coastlines of North America and in the Baltic and North seas set lower limits: 1 per cent from this July and 0.1 per cent by 2015. The net effect of the warming and cooling influences of shipping currently neutralises about 7 per cent of human produced global warming. That is about to end as the new rules will cut global sulphur emissions from shipping, and with it their cooling effect, by 80 to 90 per cent in the coming decade. Few policy issues are more complex than the effects of carbon and sulphur emissions from shipping, partly because one contributes to global warming while the other has the opposite
In this section
• Putting science into fingerprint evidence. page 10 • The perils of keeping nukes "on alert". page 12 • DidNeptune devour a super- Eart h? page 14
two centuries of steam shipping are currently heating the planet by 37 milliwatts per square metre. But at the moment, the overall effect is to cool the planet. As more and more CO2 accumulates in the air from shipping, however, warming will come to dominate. The only question is when. Veronika Eyring of the Institute for Atmospheric Physics in Wessling, Germany, says that "Wouldn't it be weird if we were forced to spend billions to do what ships have been doing for free?"
if emissions remain as they are today, the tipping point is 50 years away. The reductions in sulphur emissions planned for the next decade will push shipping into a net warming influence within that period (Atmospheric Environment, DOl: 10.1016/ j.atmosenv.2009.04.059). There is little chance of the controls on S02 being reversed and with good reason. James Corbett of the University of Delaware at Newark estimates that it currently kills around 64,000 people a year worldwide effect, and also because the impacts from lung and heart disease, of of CO2 and S02 emissions are felt which some 27,000 are in Europe. on very different timescales. Any hopes that the IMO would The climatic effect of emissions act on CO2 at the same time as from a typical ship at sea is cutting S02 emissions evaporated initially dominated by the strong with the failure of climate talks in Copenhagen in December. The cooling influence of the S02' As well as providing a direct IMO now says it awaits a UN lead. shading effect, sulphate particles also act as nuclei around which water droplets form, making skies Who's responsible? cloudier. Direct S02 shading from It could be a long wait. Like air transport, shipping was left out of today's shipping is estimated to the 1997 Kyoto protocol. Nor was cool the planet by 31 milliwatts per square metre. Though hard to there any mention of shipping in model precisely, the influence on the Copenhagen accord, intended cloud formation is likely to be as a blueprint for what should three times that. replace the Kyoto protocol in But the S02 only stays in the 2012, which was signed by more air for a few days. If it were not than 20 world leaders. constantly replaced, the warming Admittedly, setting CO2 effect of the ships' CO2 emissions emissions targets for international shipping is not easy. As with would quickly dominate. This lasts for centuries. The airlines, it is not obvious which accumulated CO2 emissions of country should be responsible,
GOOD INTENTIONS, UNFORESEEN RESULTS Sulphur dioxide is not the only pollutant that has beneficial effects. and sometimes measures intended to protect the environment can have unexpected negative consequences. Treati ng sewa ge
Recycling paper
According to a 1996 study. it may actually be less harmful to burn magazines than to recycle them. De-inking paper in order to recycle it leaves a toxic sludge of heavy metals.
Untreated sewage kills fish by generating oxygen-depleted dead zones. but it also provides food for some bird species. One study in
Mend in g the ozone hole In the 1970s, high levels of CFCs in the atmosphere caused a damaging thinning of the ozone layer. This has
2001 found that after a sewage treatment plant came on stream. the number of gulls in the affected area fell by 93 per cent.
cooled the air over east Antarctica, and temperature rises in the region are predicted to accelerate as the hole heals following a ban on CFCs.
Cutting carbon dioxide
Hydropower
The arch-villain of climate change may be boosting growth in some plants. In chambers where levels of
Rotting vegetation in newly flooded reservoirs can emit methane - a powerful greenhouse gas. Dissolved
CO2 have been deliberately boosted. plants have been shown to grow up to 40 per cent faster than normal.
methane builds up and is released when water passes through the dam's turbines. Shanta Barley
but for shipping the problem is made worse by the popularity of flags of convenience. Two-thirds of the world's ships are registered in small non-industrial countries such as Panama and the Bahamas that do not have national emissions targets. One proposed solution is to treat the entire industry as if it were a single country, with its own emissions ceiling. Developing countries say this would be unfair, because it undermines the principle that the industrialised nations should bear the brunt of emissions targets. Another suggestion is to create a tax whose revenues would go to developing nations, but the US and China have so far both opposed it. There is huge potential to cut CO2 emissions from shipping. The Danish shipping line Maersk claimed last month that by making its massive container ships travel more slowly it had cut their fuel use, and hence carbon emissions, by 30 per cent. The International Chamber of Shipping, an industry association, says better-designed engines,
hulls and propellers could cut CO 2 emissions by a further 15 to 20 per cent. And waiting in the wings are biofuels, currently being trialled by Maersk, solar panels, nuclear reactors and even a return to sailing, using giant kites. But without a cap on shipping emissions, much of this may not happen. If it doesn't, CO2 emissions from shipping are predicted to triple by 2050. That brings closer the possibility that the world will one day need to take emergency action to stave off runaway climate change. One of the most effective ways of cooling the planet, suggested by Nobel prizewinning atmospheric chemist Paul Crutzen, might then be to spray the atmosphere with sulphur. In other words, to do exactly what shipping is doing today. "502 emissions are a form of inadvertent geoengineering," says Fuglesvedt. Wouldn't it be weird, he suggests, if we cleaned up the ships and then were forced to spend billions of dollars to do just what they have been doing for free? • 20 March 2010 I NewScientist 1 9
THIS WEEK
Fingerprints to go scientific at last matched when presented with the same prints under different HOW courts use fingerprints, circumstances. Fingerprints have the icons offorensic science, also led to some high-profile mistakes. In 2004, they led the is on the cusp of a much-needed revolution. In response to claims FBI to incorrectly identify Oregon that their use is often unscientific, lawyer Brandon Mayfield as a suspect in the terrorist bombings statistical tools are now being designed to determine the in Madrid, Spain. probability that "matches" But fingerprint analysts have been slow to acknowledge the between a suspect and prints problem, and still present matches from a crime scene are spurious. to courts with no accompanying Ifused in court, these tools could vastly reduce the number of error rate - a state of affairs that shocked the US National Academy people convicted of crimes they didn't commit. But their use may of Sciences (NAS), which presented a report on US forensic science also face resistance from some last year. tiThe NAS committee was fingerprint analysts who are reluctant to give up the long-held, horrified by the testimony ofthe fingerprint analysts," says but incorrect, notion that crime scene fingerprints could only Thomas Bohan, who stepped have originated from one person. down as president ofthe American Academy of Forensic Sciences Since their first use in 1892 (see timeline), fingerprints have (AAFS) last month. "[One] guy came in and said: 'It's infallible. It formed the heart of many has a zero error rate. Ifwe say it's a criminal trials. But recently the match, there's no one else in the realisation has dawned that two prints deemed a match by an universe it could be.''' expert may in fact come from two The NAS report, which called for separate people, due to human new research to assess fingerprint error, coincidence, low-quality reliability, shook forensic prints or a mixture of all three. scientists. A year on, steps are now In 2005, Itiel Dror and Ailsa being taken to make the use of Peron of the University of such evidence more scientific. Last month the US National Southampton, UK, showed that fingerprint examiners could Institute ofjustice commissioned come to different conclusions the School ofLaw at the University of California, Los Angeles, to about whether two fingerprints Linda Geddes, Seattle
investigate error rates associated with fingerprint analysis. "Even though we have been using fingerprint evidence in court for almost a hundred years, not nearly enough is known about how often fingerprint examiners might make mistakes, or in what circumstances," says study leader Jennifer Mnookin. The plan is for fingerprint analysts and defence lawyers to use the results of this study to give judges and juries a clearer idea ofthe accuracy of fingerprint evidence. The attitudes offorensic scientists are also changing. In a 2009 survey, 75 per cent of US forensic scientists believed that
innocent people may be in jail or on death row because of fingerprint errors. That's up from 56 per cent in 2007, says Samantha Neal of West Virginia University Forensic Science Initiative in Morgantown, who presented the results at a recent AAFS meeting in Seattle. til think the NAS report has had an impact on the perception of fingerprint analysis," she says. Some analysts are now taking matters into their own hands. Cedric Neumann at the UK's Forensic Science Service in Birmingham and his colleagues have created a program that calculates the statistical weight
The trouble with fingerprints Fingerprints have been used as forensic evidence for over 100 years but are not the infallible proof they are often perceived to be
1892 World's first fingerprint bureau in Buenos Aires, Argentina, relies on bloody thumbprintto solve a murder case
101 NewScientist 1 20 March 2010
1993
2004
2004
2006
2008
us Su pre me Court rules
FBI incorrectly
DNA evidence exon erates
Police officer Shirley
US National Academy
that a known error rate
must acco mp any fo rensic evidence: this is largely
ignored by courts in the
case of finger prints
declares fingerprint of Oregon lawyer a
Stephan Cowans, who had served 7 years for
"100 per cent" m atch
the murder of a Boston
of Madrid bombings
due to his fing erprints
to pri nt fou nd at scene
police officer partly
McKie awarded
£740,000 after her fing erprint was
incorrectly linked to a murder in Scotland
of Sciences calls for an overhau I of
forensic science, inclu ding fingerprints
For daily news stories, visit www.NewScientist.com/news
Same finger, different prints
that should be attached to a given fingerprint match. Such statistics are already used when a DNA match is presented in court. Computer programs, such as those used by US immigration, can already match a scanned "Saying a fingerprint is a match or not doesn't represent the actual weight of the evidence"
"Saying something is excluded or included doesn't represent the actual weight of the evidence," says Glenn Langenburg, a certified fingerprint analyst with the Minnesota Bureau of Criminal Apprehension, who has been training US analysts to use Neumann's program. Analysts are also under no obligation to document how they reached a conclusion, so the level of accompanying information varies between labs from a little to extensive, Langenburg says. To solve these problems, Neumann's team asked 40 people to print their fingers 704 times. Then they created a program
that uses this data, together with fingerprints taken from 12,000 people, to come up with a probability that a crime scene print matches a given suspect's. "It asks 'what proportion of [features] from the suspect look like the crime scene mark, and what proportion from fingers in the general population look like the crime scene mark?'" says Neumann, who presented the program at the AAFS meeting. "Instead of going to court and saying: 'It's him because I say so, and I have 25 years' experience and I've never been wrong', I can say, 'It's him because the data supports it and here's how I came
fingerprint against a database to confirm people are who they say they are. But these require good-quality prints, whereas crime-scene prints are frequently smudged or only exist in partial form. Other programs are used to pull up possible matches from a Spot the difference database of criminal suspects, but The fingerprints above are all from the same finger. One of the prints below is also from a human analyst ultimately that finger. Can you tell which one? decides whether there is a match. This is where problems can creep B ( in. Analysts will pick a number of features from a fingerprint and compare these with the second print, declaring it either a match, an exclusion (a non-match) or inconclusive. But not all prints are of equal quality.
to that conclusion'," he says. Justice Joseph Maltese of the New York Supreme Court agrees that if validated, such a model would be a welcome addition to the courtroom. "'I know it's a match because you say it's a match' isn't good enough today," he says. "If you could buttress that with some statistical data that would be very useful." There are still some kinks to iron out. One is that the probability given by the program depends on the number of features an analyst highlights as "of interest", which can vary widely between analysts. "You could have very confused juries. We need a system to help us select features reliably, routinely and reproducibly," says Langenburg. One such tool is being developed by Virginia-based company, Noblis, in consultation with the FBI. Although the exact details are not yet public, the tool maps fingerprints for regions of high and low reliability, flagging up the areas that analysts should focus on. "It's very promising," says Christophe Champod of the University of Lausanne in Switzerland, who is working on a program similar to Neumann's. Even if fingerprint analysis can be made more consistent, there's also the issue of what happens in court. "It will be interesting to see what jurors make of it," says Christine Funk ofthe State of Minnesota Board of Public Defense. "For my whole career, it has always been definitive that a fingerprint either belongs to an individual or it doesn't. For me as a defence lawyer it says: 'this isn't an absolute certainty'." Langenburg agrees that a statistical model may make it easier for defence lawyers to undermine fingerprint evidence, a big fear for some analysts. "They have been taught not to open the door for the defence," he says. But if analysts are serious about transforming their field into a scientific discipline, that's a risk they may have to take.• 20 March 2010 I NewScientist 1 11
THIS WEEK
INSIGHT What's the point of keeping nuclear weapons on instant alert?
immi nent attack by Russia, says policy
This is a pa rti cular risk in Russia,
analyst James Acton of the Carnegie
which still relies on agei ng Soviet
Endowment for International Peace,
era radar and satell ites to scan for
a Washington DC -based thi n k ta nk
.
i ncom i ng missiles. In 1995, the
I N THE next few weeks, President
is a cause for concern, "De-alerting is
Barack Obama will publish his delayed
the key problem," says Ivan Oelrich of
because a malfunction could lead
Norweg ian weather satellite launch
Nuclear Posture Review (NPR), setting
the pressure group Federation of
to accidental launch or could be
for an incoming missile,
outthe role nuclearweaponsplay in US
American Scientists.
defence, This is Obama's opportunity
To deter or respond to an attack,
Missiles on alert are a worry partly
hijacked - but mostly because they
Russian mil itary briefly mistook a
To avoid such mistakes, Russia
cou ld be launched by misinformed
and the US have opened a monitoring station in Moscow to observe each
to end one of the most dangerous
nations don't need to keep weapons on
or pressurised mi l itary leaders or
legacies of the cold war: the nuclear
alert, says Oelrich. No country could take
politicians during a fast-evo lving
other's missile launches. To minimise
missiles the US and Russia keep ready
out all US missiles in a fi rst stri ke, so a
situation, Oelrich says.
the consequences if an accidental
to fly in min utes, The signs are that he
reprisal would not need to be speedy.
is unl ikely to take it
The only reason to have so many on
Nuclear missiles "on alert" could
missiles on alert are now targeted
alert would be to pre-empt a large
too easily be launched by accident
atthe mid-ocean ,
This leaves the questions why
launch does occur, Russian and US
does the US keep its nuclear weapons
Missiles can b e taken off alert by
"on alert", and are they really needed?
screwing down switches or removing parts, so that it would take hours or
The NPR is expected to state that the US will not use its nukes to attack
days to launch them, But as these
a country that does not itself have
alterations cannot be observed by
nuclear weapons - as long as that
the other side, this will not i nduce
country complies with the Nuclear
them to stand down as well. One way to make verifi cati on
Non- Proliferation Treaty - and it may renounce nuclear weapons as a
easier would be to keep warheads
response to chemical or biological
and missiles in separate buildings,
attack. It may also say 2500 "spare" US
as China already does. With this
nuclear warheads will be destroyed,
arrangement, any assembly work could be spotted by satel l ite,
But it is not expected to pledge
Weapons on alert risk more than a
that the US will never be firstto
US-Russian stand-off. At a meeting in
launch a nuclear strike, northat nuclear weapons are only for
May, non-nuclear nations may decide
deterrence or response to nuclear
to withdraw from the Nuclear
attack. This policy means that the
Non-Proliferation Treaty, which calls
US, along with Russia, wi l l cont i nue
for nuclear nations to disarm. If the US
to keep 1000 to 1200 nuclear missiles
says it still needs nuclear missiles
"on alert". Forthose who support the
ready to fly, they may feel they need
elimination of nuclear weapons that
them too, Debora M acKenzie .
Passing star could stir up solar system A STAR is hurtling towards us. It will almost certainly clip the outskirts of the solar system and send comets towards Earth - though not for a while. Vadim Bobylev of the Pulkovo Observatory in St Petersburg, Russia, modelled the paths of neighbouring stars using data from the European Space Agency's Hipparcos satellite and from ground-based measurements of the speeds of stars. 12 1 NewScientist 1 20 March 2010
He found four previously unidentified stars that will pass within rough ly 9.5 light years of Earth. They will tug on the Dart cloud, a diffuse cloud of icy objects around the solar system thought to be a reservoir of comets. However, the biggest threat comes from another star, Gliese 710, an orange dwarf now some 63 light years away but zooming our way at 14 kilometres per second. Previous studies have suggested that Gliese 710 could pass through the Oort cloud in about 1.5 million years. Bobylev's calculations suggest Gliese 710 has an B6 per cent chance
of passing through the Dart cloud (Astronomy Letters, vol 36, p 230). That cou Id scatter millions of comets into paths that cross Earth's orbit. Fortunately, previous work on the effect of a star tangling with the Oort cloud hints the comets would arrive in a trickle, with only one entering an Earth-crossing orbit per year. Gliese 710 also has a 1 in 10,000 probability of coming within 1000 astronomical units of us - 1 AU being
"Gliese 710 could scatter millions of comets into paths that cross Earth's orbit"
the distance from the Earth to the sun. Such a path could jostle objects in the Oort cloud, the Kuiper belt a swarm of icy objects beyond Neptune's orbit - as well as others that orbit in a disc between the two regions. The star could also change Neptune's orbit a fraction, says Paul Weissman of NASA's Jet Propulsion Laboratory in Pasadena, California. "It would be a very significant event." Although an encounter with Gliese 710 was already thought possible, "it's nice to see it confirmed with a better model and better data", says Weissman. "It's a solid piece of work." Rachel Courtland .
Conversations for a Smarter Planet: No,2 in a Series
,
A
I \ I
new i ntel l igence for a smarter planet.
Leaders make decisions, A n d their decisions rely o n information,
Thankfully, no. Technology exists to capture, process and turn all this
That always holds true, whether they're leading a company, a
data into actual intelligence, Recognise patterns in unprecedented
government, an army or a household, It's what inspired the revolution that saw the I n formation Age supplant the I ndustrial Age. Shifted the basis of competition to
detai l . Capture and analyse changes in markets, trends and consumer preferences faster, And optimise highly complex systems and organisations in entirely new ways,
knowledge, expertise and intellectual capital, the ultimate value of
New approaches l ike stream computing use advanced software
information, And created a torrent of decision-making information.
algorithms to track new stimuli, analyse data- i n-motion, correlate it
Today we see the technology industry's real value was never about
with other relevant i nformati on. And plug directly into operational
chips, computers or software, But about revealing what had happened,
and logistics systems, closing the gap between thinking and doing .
was happening and might happen across the enterprise, Can you
I ndeed, advanced analytics built on heavy-duty mathematics are
spot key patterns? Extract critical insights from data? Or remove
starting to move us from sense and respond or real tim e decision
latency and cost from decision-making and implementation?
making to something l i ke prediction,
Questions like these can now be answered far more accurately than
This really could change how the world works. Already, insurance
ever, But today the ante is being upped by the volume and variety of
companies see patterns in bill ions of claims, and detect the
information,and the velocity of decision-making on a smarter planet.
fraudulent few, Police correl ate street-level information from myriad
How much? By 201 0, the amount of digital i nformation in the world
observations and devices to identify crime patterns - and prevent,
is predicted to double every 11 hours,
What kinds? Information is being created by bill ions of people.
Flowing from a tri l l ion intelligent devices, sensors and a l l manner of
instrumented objects, animate and inani mate, In al l , 80% of this new
rather than punish it. Retailers optimise inventory and transport systems by l i nking what's in stockto weather forecasts - surprisingly better ind icators of consumer behaviour than weather itself, The list is long , and the change i s just starting, Imagine how it w i l l
data growth is unstructured content: email, documents, images,
transform the way w e pursue economic growth, societal progress,
records, video, audio and more,
environmental sustai nabi l ity and cures for disease, The way we
How fast? To match the speed of transactions, today's systems take
i nteract with each other and with the world.
in event information in real time, then correlate, analyse and act over
Let's build a smarter planet. Join us and see what others are thinking
200 times a second - faster than a humming bird flaps its wings,
at ibm.com/lhink/uk
So are we doomed to more blind spots, more needles i n h aystacks, more garbage in, more opportunities lost while analysing data?
IBM, the IBM logo, ibmcom and the globe design are trademarks of I nternational Business Machines Corporation, registered in many jurisdictions worldwide, A current list of IBM trademarks i s available on the Web at 'Copyright and trademark information' at www. ibm.com/legalicopytrade. shtml
THIS WEEK
Did Neptune devour planet to get Triton? State University in Tempe. Neptune's peculiar moon NEPTUNE may have polished off a Triton may once have been paired super-Earth that once roamed the with this hypothetical super Earth, Desch and colleague Simon outer solar system and stolen its moon to boot. The brutal deed Porter now say. Triton is larger could explain mysterious heat than Pluto, and it moves through radiating from the icy planet and its orbit in the opposite direction the odd orbit of its moon Triton. to Neptune's rotation, suggesting that it did not form there but was Neptune's own existence was captured instead. a puzzle until recently. The dusty cloud that gave birth to the For Neptune to capture Triton, planets probably thinned out the moon would have had to slow furtherfrom the sun. With down drastically. One way to do building material so scarce, it is this is forTriton to have had a hard to understand how Uranus partner that carried away most of the pair's kinetic energy after an and Neptune, the two outermost planets, managed to get so big. encounter with Neptune. In 2006 researchers argued that Triton But what if they formed was initially paired with another closer in? In 2005, a team of scientists proposed that the giant object of similar size that wound planets shifted positions in an up being gravitationally slung early upheaval (New Scientist, into space after the pair ventured near Neptune (New Scientist, 25 November 2006, p 40). In this scenario, Uranus and Neptune 13 May 2006, p 8). formed much closer to the sun But Triton could have slowed even more if its former partner and migrated outwards, possibly were a heavy super-Earth. swapping places in the process. That would have left behind That's because a more massive enough material just beyond their body could carry away more of the birthplace to form a planet with pair's kinetic energy, Desch twice the Earth's mass, according calculated in a study presented to calculations published in 2008 earlier this month at the by Steven Desch of Arizona Lunar and Planetary Science David Shiga, Houston
corruption raises doubts over ivory sales ACCUSATIONS that wildlife conservation officials and rangers in Tanzania have colluded in elephant poaching have emerged in a report to the Convention on International Trade in Endangered Species (CITES). The accusations are important because Tanzania has asked the 175 governments attending the triennial summit of CITES in Doha, Qatar, this 14 1 NewScientist 1 20 March 2010
Conference in Houston, Texas. "It would be a lot easier to capture Triton if it were orbiting something bigger," he says. Neptune may have engulfed the super-Earth. Heat left over from the impact could explain why the planet radiates much more heat than its cousin Uranus, which is similar in mass and composition, Desch says. But Douglas Hamilton of the University of Maryland, College Park, one ofthe authors ofthe 2006 study proposing that Triton
had a long-lost twin, points out that smaller bodies would have been common in the early solar system, before planet migration cleared many of them away. Neptune would therefore have had many opportunities to snag Triton from one of these punier objects, rather than from a much rarer super-Earth, so that explanation may still be more likely, he says. Even so, he is not ready to rule out Desch's idea: "It's worth pursuing to see where it will lead." •
week to allow a one-off sale of its
from Kenya for a fresh 20-year
serious doubts about its
stockpi led ivory. The ivory comes from legal sources, such as elephants dying naturally. Zambia has applied for similar permission.
moratorium on all sales. The meeting will be influenced by two reports, one on Tanzania and one on Zambia, compiled and issued by
government's ability and will to tackle poaching. It warns that 30,000 elephants have been killed illegally
Most conservationists are strongly opposed, claiming the sales would
the CITES secretariat just prior to the summit. Both endorse sales in their countries, provided the proceeds fund anti-poaching measures and conservation programmes. Yet the report on Tanzania raises
encourage poaching. They say that a moratorium agreed in 1989 hasn't worked because oftwo earlier "oneoff" sales of stockpiles, in 1999 and 2008. "Selling the stockpiles now, when trade is already out of hand, "Some anti-poaching staff colluded in illegal killing is ridiculous," says Samuel Wasser ofthe University of Washington in of elephants and illegal Seattle. Instead, they back a proposal trade in ivory"
since 2005 and cites "several" witnesses who said that "some antipoaching staff colluded in illegal killing of elephants and illegal trade in ivory", which involved "higher staff ofthe Wildlife Department". The panel of authors admits it has no direct evidence to support the allegations, but says it received so many that "it would be failing in its duty to CITES if it did not refer to them". Andy Coghlan .
For daily news stories, visit www.NewScientist.com/news
How even simple line drawings move the brain one method of creating "implicit motion", used by an 18th-century japanese artist, works so well. While admiring line drawings by
Previous research has shown that blurred photographs stimulate the same regions of the visual cortex as real-life motion. including the extrastriate visual cortex. To find out whether sketches of unstable bodies would also activate these regions. Osaka showed japanese students
Hokusai Katsushika. psychophysicist Naoyuki Osaka of Kyoto University. japan. was struck by the vivid motion
Katsushika's drawings while scanning their brains with functional MRI. The scans revealed that drawings
10.1097/wn r.Ob013e328335b371).
in Perth. warns that the influence
they convey. Instead of using blurto suggest movement, as much modern
Patrick johnston. a cognitive neuroscientist at Swinburne University of Technology in Melbourne. Australia. says these findings could help "unlock how the brain processes visual information".
of culture must not be ignored. japanese people may perceive the
art has done since the advent of photography. Katsushika created motion by drawing bodies in highly unstable positions (see picture). This
depicting motion did indeed prompt activity in the extrastriate visual cortex. unlike those of people or objects in static positions. Osaka concludes that there is a "common neural pathway" for interpreting
is thought to work because the brain "fills in" the effects of gravity pulling the bodies down.
implicit motion in art that is similar to the pathway used for perceiving real-life motion (NeuroReport. 001:
However. Oron Catts of SymbioticA. a biolog ical arts centre at the University of Western Australia
people are trained to read those cartoon images as the representation of movement." Wendy Zu kerman .
I N THE YouTube age it i s easy to forget that artists rely on clever tricks to create a sense of motion in still images. Now brain scans show why
...... .", Home Office
Department for
Transport
CPNI
Centre for the Protection of National Infrastructure
Working together for a safer London
motion more vividly than people from other cultures because they are accustomed to this type of art. he suggests. "In japanese culture.
E N RE
Explosives and Weapons Detection Cal l for Innovative R&D Proposals Al most every day, w e hear news o f terrorist attacks a n d conspi racies, h i g h l ighting t h e need for secu rity tech nolog i es to keep pace with the chang i n g th reats. I n s u p port of the UK's Cou nter Terrorism Strategy (CONTEST) ; the Home Office, Department for Transport, Centre fo r the Protection of Natio nal I nfrastructure, M O D Counter Terrorism Science and Tec h n ology Centre and the Metropolitan Pol i ce Service are i nviti ng UK compan ies and acad e m i c i nstitutions to s u bm it i n novative proposals in the field of explosives and weapons detecti o n . Visit http ://www. homeoffice.gov.u klrds/whatsnew1 .htm l for further deta i l s about registering a n d completing our mandatory pre-q ualification question naire. The dead line for completed questionnaires is 1 6th Apri l 201 0. If you meet o u r sel ection criteria you will be invited to a bi dders' conference (anticipated to be held i n London i n May
201 0) where you wi l l
receive more d eta i led i nformation regarding this exciting challenge and our spec ific
req u i rements for this research cal l . Th is call i s being conducted i n assoc i ation with the Home Offi ce I n novative Sci ence and Tech nology i n Cou nter-Terro rism ( I N ST I N CT) pro g ramme. For security reasons the organisers reserve the right to refuse admittance to the bidders ' conference and further participation.
20 March 2010 I NewScientist 1 15
I N B R I EF
Moon marriage gives Jupiter a ring
Gorillas will deliberately lose a game to keep a playmate CAJOLING bored friends to keep playing with you is not limited to humans. A gorilla that wants to continue a game will also try to do this, and will even deliberately lose if necessary. This hints that gorillas may have "theory of mind" - the capacity to attribute mental states to others. Richard Byrne and Joanne Tanner of St Andrews University in the UK videoed gorillas at San Francisco Zoo. As well as engaging with a toy and another gorilla, the animals seemed aware of their playmate's interaction with the toy. "The gorillas could encourage their playmates when they were losing interest, or self-handicap if there
was a danger of winning the game," says Byrne (Animal Cognition, 001: 10.1007/s10071-009-030a-y). This is the first time animals have been observed
JUPITER may have a new ring that was created by a smash between moons. The possible ring appears as a faint streak near Jupiter's moon Himalia in an image taken by NASA's New Horizons spacecraft. It is unclear if it reaches all the way around the planet. No one knows when it formed, but the Galileo spacecraft didn't spot it before the end of its mission in 2003, says Andy Cheng ofthe Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. The structure may be the result of an impact that blasted material off Himalia, suggest Cheng and colleagues in a study presented at the Lunar and Planetary Science Conference in Houston, Texas, earlier this month. One of Jupiter's moons called S/2000 '11 went missing after its discovery in 2000 and could have crashed into Himalia, destroying itself in the process, says the team.
following a playmate's interaction with a third object a skill picked up by humans at 9 months old. With dogs, cats, lions and bears "the animal wants to win the game, ratherthan keep it going", Byrne says. "This is different to throwing a stick for your pet dog."
Fusion fears bite the dust
Because the gorillas seem to be taking account ofthe thoughts of others, they are showing some theory of mind competence, says Byrne, although they do not pass a standard theory-of-mind test called the false belief test, which looks at the ability to infer another's perspective. Nevertheless, Byrne says that taking another individual's thoughts into account might not be unique to humans.
'Wasabi sense' detects rattlers' prey WHAT does a rattlesnake's night vision have in common with the taste ofwasabi sauce? It turns out that when some snakes "thermally image" their prey, they employ receptors similar to those we use to sense the pungency ofwasabi. Unlike our receptors, which respond to odour molecules, the snakes' thermal receptors respond directly to heat, triggering nerve impulses that 16 1 NewScientist 1 20 March 2010
their brain interprets as an image. "It's hard to know exactly what the snake sees', but one assumes that the thermal image in some way depicts the relative thermal intensity of an object or animal," says David Julius ofthe University ofCalifornia, San Francisco, whose team has found the link (Nature, DOl: 1O.1038/nature08943). "It's probably not unlike a thermal camera." I
Julius's team compared gene activity in different types of nerve cell from diamondback rattlesnakes, which all have shallow pits on their faces that detect heat. They found that in nerves that feed the pits, a gene called TRPAI was 400 times more active than elsewhere. The gene makes a protein that activates the cells when it detects heat from objects at more than 27 dc. Boas and pythons have similar molecules on their snouts.
FEARS that "toxic dust" could choke efforts to get power from nuclear fusion have been allayed. Hot plasma in fusion reactions bites pieces from the reactor walls, creating metallic dust. The worry is that this could clog instruments and even choke reactions in the experimental reactor ITER, set to fire up in southern France in 2019. Michael Coppins of Imperial College London noticed that dust grains in existing reactors are often spherical, implying that they had been molten. He calculates that in ITER's plasma such liquid drops should be torn apart by electrical forces before they can cause trouble (Physical Review Letters, DOl: 10.1103/ physrevlett.104.06S003).
For new stories every day, visit www.NewScientist.com/news
'Bug' prints can put you at crime scene YOU might call it "C51: Microbe". Our fingers are home to a unique collection of bacteria that get left on surfaces we touch. By comparing bugs found on a person's hand to those recovered at a crime scene, you might be able to identify the perpetrator. "There are certain situations where human DNA analysis or standard fingerprinting doesn't work," says Noah Fierer, a microbiologist at the University of Colorado in Boulder. His team knew that microbial communities on skin tend to be unique to the individual and change little overtime. To see if these qualities could be applied to forensics, his team swabbed several computer keyboards and the fingertips of their users, then identified about 1400 different kinds of bacteria living on each, using DNA sequencing. The keyboard bacteria closely matched their owner's fingertips (Proceedings of the
National Academy of Sciences, 001: 10.1073/pnas.1000162107). In another test, Fierer's team were able to correctly match nine computer mice with their owners. The "microbeprint" seems to be long-lasting: swabs left at room temperature for two weeks could be matched to owners. But accuracy issues mean you won't see them used in courtjust yet, Fierer says.
Levitate cells to produce 3D tissue samples IRON-RICH cells that grow into balls when "levitated" by magnets could provide a new way to study cancer in the lab - and to produce replacement tissue for grafts. The magnets can sculpt balls into shapes that resemble tumours and tissues growing in the body. Glauco Souza ofNan03D Biosciences in Houston, Texas, and his colleagues incubated human glioblastoma cells from brain tumours with iron oxide and bacteriophages - viruses that infect bacteria and can bind to, but not harm, mammalian cells.
The phages gobbled up the iron oxide, attached themselves to the cells and then injected the cells with their magnetic cargo. Next the team placed the cells in a Petri dish half filled with a gel and covered it with a magnetic lid. The cells rose from the bottom of the dish in response to the magnet and clumped together at the interface between the gel and the air. After 72 hours, a sphere of cells 1 millimetre in diameter had formed. Protein expression in these glioblastoma cells more closely mimicked that
in real cancer cells than in 2D cultures of cells, indicating that this method could be used to study cancer (Nature Nanotechnology, DOl: 10.1038/ nnano.201O.23). Exposed to both air and fluid, the cells might also be used to model the lungs and test drugs for lung disease. The researchers also found they could create cell balls of different shapes by moving the lid, changing its shape and the strength ofthe magnet. This might allow skin and long, thin nerve grafts to be grown in the lab.
Psychopathy is its own reward A LACK of emotion isn't the only thing driving psychopaths: the brains of people with some psychopathic traits may overvalue the reward associated with getting what they want. In extreme cases, this may result in callous and manipulative acts. Psychopathy is a spectrum of traits including fearlessness, callousness and narcissism; people in whom a number ofthese traits are strong are classed as psychopaths. Brain areas involved in emotion are less active in such people, but this can't explain other behaviour common to psychopaths, such as drug abuse. Now Joshua Buckholtz of Vanderbilt University in Nashville, Tennessee, has discovered that people who are unusually willing to manipulate others for their own ends - another psychopathic trait -have brains that are unusually rich in dopamine, a "reward" chemical that makes us seek pleasure, be it from drugs or getting what we want (Nature Neuroscience, DOl: 10.1038/ nn.251O). Buckholtz suggests that this extra reward urge could drive psychopaths to act without considering the costs of their actions - such as hurting others.
Brainy octopus lacks personality OCTOPUSES make for discerning TV viewers: they respond to high
TV as ifthey were real. They lunged forward as if to attack crabs, and
definition images but not traditional cathode ray images. What's more, in the first study to trick octopuses into believing video images are real scenes, the cephalopods turn out to lack "personality" or consistent behaviour. It wasn't possible to study octopus behaviour using video before because their eyes were not fooled by slow cathode ray images. But in this study, 31 gloomy octopuses (Octopus tetricus) reacted to 3·minute films on high·definition
cowered from other octopuses, according to Renata Pro n k at Macquarie University in Sydney, Australia, and colleagues ( The Journal of Experimental Biology, 001: 10.1242/jeb.04067S). The team found thatthe octopuses did not behave consistently from day to day - they might be bold one day and shy the next, for instance. The team say this suggests Octopus tetricus do not have personality - a trait which may allow itto adapt to its changing environment.
20 March 2010 I NewScientist 1 17
Subscribe today and get a copy of the latest New Sci entist book 'Do Polar Bears get Lone ly?' FREE
For daily technology stories. visit www.NewScientist.com/technology
TECHNOLOGY
Clean energy from noise poll ution
Virtual ears know good acoustics
EVERY drop of water i s stuffed with the greenest of fuels, hydrogen, but getting it out is a challenge. A new material raises the prospect of doing so using noise pollution -from major roads, for example. A team at the University of Wisconsin-Madison made crystals of zinc oxide that, when immersed in water, absorb vibrations and develop areas of strong negative and positive charge. These charges rip apart nearby water molecules, releasing hydrogen and oxygen gas (Journal ofPhysical Chemistry Letters, 001: 1O.1021/jz100027t). "This is like a free lunch," says lead researcher Huifang Xu. The crystals release hydrogen with energy equivalent to almost 20 per cent of the sound energy absorbed, he says, and could make fuel from the noise of anything from machinery to crashing waves.
ARCHITECTS aiming to create rooms with crowd-pleasing acoustics could soon rely on a pair of virtual ears to sound out their designs. The software·based ears are the brainchild of John Culling at Cardiff University in the UK, and colleagues, who think they can be used to transform blueprints into "sound maps" which show how discernible speech would be, compared with background noise, at various positions in a room. Their virtual ears address a particular acoustic problem: singling out a voice against
of the energy used by the soon-to-be opened Strata tower in London will come from wind turbi nes built into its roof
background babble. Culling's system models how sound should travel in a room, then it works out how two competing sources would be perceived at a range oflocations around the room. The team created models of rooms and assumed their virtual ears would be 1.5 metres above the floor - to simulate human ears. It was then used to predict whether someone standing at a given location would be audible above a noise source at a third location a proxy for ambient chatter. The results tally closely with those obtained when human volunteers were asked to assess audibility in test environments (Journal of the Acoustical Society ofAmerica, 001: 10.1121/1.3268612).
"Consumer electronics have been feed ing i nto th is wa( An illicit trade in minerals used in devices such as cellphones is fuellin g violence and human rights abuses in the Democratic Republicofthe Con g o, says David Sullivan atthe Center for
American Progress, a th i n k ta n k based in Washington DC( The Boston Globe, IS March)
20 March 2010 I NewScientist 1 19
TECH NOLOGY
Made-to-order malware becomes a reality Cyberspace cou ld soon get much more dangerous, thanks to new p rograms which a l l ow anyone to b u i l d their own virus or mal icious software makes it easier than ever to create and spread malware. "INTERESTED in credit card "There used to be only a small theft? There's an app for that." number of clever criminals who So says Gunter Ollmann, a could pull off these attacks," says security researcher at Damballa, Patrick Peterson of online security a company based in Atlanta, company Cisco in San Bruno, Georgia. He and others are California. "Now there is a much lower barrier to entry." warning of a burgeoning cybercrime service industry, One such software kit, one which lets people with next known as Zeus, epitomises the to no programming skills steal commercialisation of the malware a fortune in cash or get hold of services industry. Like other sensitive government documents. malicious software, Zeus can easily be bought online, in this Would-be hackers have long been able to buy rudimentary case for between $400 and $700. software packages that can be Detailed instructions on how to used to build malware, such as use it are readily available, too. code that can steal online banking What sets Zeus apart is that it passwords. Now these hacking enables someone with minimal tools are being supported with computer skills to create sophisticated malware that can a range of services, some with a be used to steal online banking money-back guarantee, that Jim Giles
Hitting back at hackers There is no anti-malware magic bullet. but a range of techniques are emerging that can help limit the damage malware causes. For example. nobody should accept friend requests on online social networks from people they do not know. Hackers have created fake profiles and used these to persuade workers at several large firms to follow a link that installs malware. And, of course. you should never
likely to slip up at some point. To protect against that. in-house security teams should be thinking about going beyond standard antivirus protection. says John Pirc, a director at the IT security firm McAfee. in Austin. Texas. One option. called session· based analysis, involves monitoring all computer traffic into and out of a
a trusted contact. Companies and other large organisations are vulnerable,
company. The aim is to spot suspicious patterns of activity. such as data flowing to a computer in a country that the company does not do business with. Pirc says that the approach can pick up danger signs even if no identifiable piece of
however. because employees are
malware has been detected.
click on a link in an email unless you are certain the message comes from
20 1 NewScientist 1 20 March 2010
credentials or sensitive documents. "It represents a sea change in innovation, beyond anything we've seen before," says Peterson. As an example of what is possible using Zeus, one recent attack netted sensitive US government documents, reports Nart Villeneuve, a security researcher at the Munk Centre for International Studies at the University of Toronto, Canada. The attack began in February with a series of emails sent to senior officials in the US military, the Federal Aviation Administration and other government agencies, purporting to contains links to vital security information. In reality, clicking on the links resulted in malware built with Zeus being installed on the user's machine. The attack was sophisticated enough to dupe some of its targets, and as a result 81 machines were compromised. Villeneuve was able to identify 1533 documents from the compromised machines that ended up on a computer in Belarus, including defence contracts, documents relating to biological and chemical terrorism and the security plan for a US airport. The identityof the person who siphoned off the documents is unknown. The ease with which Zeus can be used has been enhanced by the support services, including customised hacking tools, that have grown up around it, OHmann says. If, for example, criminals know thatthe computer they are targeting is in Spain, they
, I I
can plug in additional software designed to mount attacks on Spanish banks. Plug-ins like this are available online for around $30, Ollmann says. The key to successful malware lies in tricking users into unwittingly installing it. And now even dilettante hackers can spread their malware by paying more technically adept criminals to do it for them. "Hackers can upload malware to a site that will make it unrecognisable by antivirus software"
Peterson cites the example of Fragus, a sophisticated piece of software he first observed last summer. Fragus is deployed initially by skilled hackers, who break into web servers and install it. Once in place, it searches for vulnerabilities in the browsers used by visitors to these websites.
J
For daily technology stories, visit www.NewScientist.com/technology
INSIGHT Online translation services learn to bridge the language gap EVEN in an era of global networks
translation research at Google,
and cheap travel, i nternational
His team's Translate service can
communication still faces one great
cu rrently operate between
barrier: we don't all speak the same
52 different lang uages and he is
language. But that gap is narrowing asonline translation services advance, Recently lau nched website
translators, "A speaker of Bengali
Meedan tra nslates Arabic- lang uage news stories into English, and vice
Though translation algorithms
alongside each other, Comments in
have improved, some human
either language are instantly
intervention is still needed to
translated, A new site for bloggers
,
provide a translation that reads well.
called Mojofiti, automatically makes
Meedan's news articles, for example,
posts available to readers i n 27
are machine translated and then
languages, And Google now has a tool
tidied up by editors, Google's Too lkit
that will eventual ly allow anyone with
for professional translators produces
-
a camera phone to photograph, say,
a machine translation for them to tidy
a German restau rant menu, send the
up, in the process providing feedback
image as a mu ltimedia message to
to the software to i m prove its
Google's servers, and get an English
tra nslation capa bili ties,
translation sent back to them, All these services ulti mately rely on
of malware built with Zeus, another layer of cybercrime activity is devoted to finding ways to bypass those protections. To check whether a piece of malware is on the security companies' blacklists, hackers can send their creations to websites such as virtest.com, which for just $1 will try the code out on more than 20 antivirus products. If the malware fails the test, would-be criminals can simply upload their malware to another site that will tweak it to render it unrecognisable. The online security industry is warning that this profileration of "malware as a service" products is likely to result in far more potent attacks. There is already anecdotal evidence that hackers are paying more attention to company rather than personal bank accounts, for example, and to breaching government computers, says Villeneuve. •
can only experience a tiny fraction of
a per cent of the web," says Och,
versa, and displays the two versions
If it finds a way in, Fragus can be programmed to covertly send a piece of Zeus-created malware to the visitor's computer. This allows hackers to sell malware installation as a service to less skilled criminals. Fragus also delivers feedback on which browsers it has cracked and where the users ofthose browsers are based. "That data can be used to target a particular country," says Henry Stern, a colleague of Peterson's at Cisco. Stern says he is currently aware of a few dozen websites infected by Fragus, and that it had previously been used to deliver malware to people accessing websites belonging to a Widely read US newspaper. Zeus and Fragus can be reined in (see "Hitting back at hackers"), but even here the malware service industry is trying to stay one step ahead. So while many companies provide software that, for example, can detect the presence
ai m ing to add more, especially
those previously ignored by machi ne
With the right help even someone that speaks only a single language
a technique called statistical machine
could produce results as good as
translation, in which software learns to
those of a professional says Phi lipp
translate by using brute mathematics
Koehn of the University of Edi n burgh,
to compare large collections of
,
UK, His service, Caitra, outputs
previously translated documents, It
several possible phrases if it is
then uses the ru les it has lea rned th is
uncertain which one is correct. This
way to determine the most l i kely
lets a monoglot user fix garbled
translation in future, "Whenever there is a possibi lity of the language barrier preventing someone from do i ng someth i ng there should be the possibil ity to translate,"
says Franz Och, who leads machine
phrases that would otherwise be unfathomable without readi ng the origi nal . Tom 5i monite • Can't understand a word of it? Try getting it translated online
20 March 2010 1 NewScientist 1 21
TECH NOLOGY
the data transmitted from this, the algorithm can work out the wearer's position relative to a known start point - perhaps the point where GPS was lost. The system would be less motion sensors, David Dungate ofTessella told the SpaceTech cumbersome than existing conference at the Rutherford motion-sensing devices Appleton lab in Oxfordshire, footstep-detecting trackers worn UK, last week. The motion sensor on the foot or ankle, Dungate says. worn by the soldier is a matchbox But the microchip sensors sized unit containing three are prone to producing additional noise, resulting from variations microchip accelerometers and three gyroscopes mounted at in power supply, temperature and the like, making it tricky to right angles to each other. Using
Motion senso rs find l ost troops when G PS cuts out KNOWING where troops are during combat operations can be a matter oflife and death - but GPS technology used to track troops is fragile, the signal easily lost. Now a UK company is developing a lightweight, wearable tracker that can provide location cover when GPS is down. The system uses novel software to decipher position data from the signals generated by cheap microchip-based motion sensors - like those used in the Nintendo Wii and Apple iPhone. The device is being developed by Tessella in Stevenage, Hertfordshire, which normally develops orientation software for spacecraft like the European Space Agency's Herschel Space Observatory, launched last year. The software fuses data streaming from an on-board star-tracking camera with data from laser gyroscopes, enabling the system to gauge the craft's position in space and its rotation. These algorithms can also discern location when used with
is called Multipath Exploitation Radar. The agency has been exploring
told NewScientist. The team anticipates that using reflected radar will cover more ground than a line-of-sight system, making it possible to monitor a city of about 1000 square kilometres, such as Baghdad, with just three airborne
how MER might work by driving vehicles around a simulated urban area and collecting returns from an
radars. The three-dimensional model of a city needed to make sense of the reflection pattern could be created
Nowhere to h ide from a i rborne radar that sees rou nd corners WHY jump in a cab to "follow that car" when an airborne drone could do the job for you? The US Pentagon's Defense Advanced Research Projects Agency is developing a radar system which sees around corners and down into "urban canyons". DARPA hopes to be able to track vehicles across
overhead radar. Its researchers are
an entire city using just a few uncrewed aircraft. Traditional radar relies on direct line of sight, so it's tricky to track a vehicle that keeps nipping behind buildings. But DARPA bel ieves that by using
aiming to combine the radar data with "By using buildings as a three-dimensional map of the test mirrors, it will be possible environmentto calculate how the to identify a target vehicle from radar reflections" radar reflects off and between vehicles and buildings. This process should highlight which signals in using LlDAR, the optical surveying technology which is routinely the returning radar data can be used to plot the target vehicle's path. carried on aircraft.
buildings as mirrors, it will be possible to identify a target vehicle from radar reflections. The experimental system
MER is expected to be compatible with the radar systems currently used to track vehicles, a DARPA spokesman
22 1 NewScientist 1 20 March 2010
MER makes use of Ku-band radar frequencies of between 12 and 1B gigahertz. It is sensitive enough
get reliable data to work from. Tessella is examining the noise produced by commercial motion sensors - like those used in smartphones - to look for characteristic patterns that filtering algorithms could use to determine which signals are relevant. These algorithms, or "Kalman filters", use past data to predict how noise is likely to affect a signal, aiming to produce measurements close to their true value. "We're already showing that [applying the algorithm to1 some of the data correctly eliminates errors," says Dungate. "Our algorithms wring the data's neck to get every last bit of info." The company hopes to have its tracker working in six months, and claims defence contractors have already shown interest. If it works, it will be boon way beyond the military, says Bob Cockshott, head of location and timing at the UK's National Physical Laboratory in reddington, Middlesex. "There's a huge need for a non-GPS technology, not only for use when jamming is being used, but locations like urban canyons where GPS simply can't reach." Paul Marks .
to produce distinct signatures for apparently similar vehicles, by detecting slight differences, such as the angle of an aerial or a wing mirror. DARPA is also looking to develop an algorithm which would enable the system to track multiple vehicles. Ain Sume of the Swedish Defence Research Agency says the "sound, well-known physical principles" behind MER make it feasible. His team built a radar system that detects people around a corner by using reflections from the opposite wall. But Sume reckons it will take some time to turn DARPA's plans into a viable system. Key challenges include maintaining a radar lock as the view shifts from line-of-sight to reflection and back, and establishing a unique radar "fingerprint" for each vehicle. David Hambling •
OPIN ION LETTERS
Climate impacts
agriculture could be reduced by up to 50 per cent by 2020". From Martin Parry, Imperial We did not conclude there was College London, and nine others a simple link between worsening On behalfofthe authors of those natural disasters and climate change. The graph to which your parts of the IPCC report on the impacts of climate change that story refers is not in the published were criticised by Fred Pearce chapter but appears in the supporting material. (27 February, p 8) may I reply Our biodiversity risk calculation to his points? He describes our interpretation was based on 19 studies, two of a of Nigel Arnell's work on the global scope, and had no single study as a "key source". It took impact of drought in Africa as "questionable", implying that into account the relevant critical we ignored findings that in some literature while balancing possible regions climate change will reduce over- and underestimation. We have always tried to be water stress. We specifically sought Arnell's advice on this. He believes clear about uncertainties in our it is appropriate to use only the current knowledge and welcome questions about findings in the number of people exposed to increased water stress as the report, which is why we were headline impact indicator. In fact, happy to provide Pearce with your story misrepresents Arnell's many pages of explanation of original paper, which did not give our workings. But none ofPearce's "equal prominence" to increased findings undermine the conclusions of the assessment. impact and reduced impact. Nothing in your report London, UK undermines the IPCC's headline message that "agricultural production... in many African Peer pressure countries ... is projected to be severely compromised by climate From Deepa Coleman variability and change ... In some Alan Thorpe's defence of beleaguered climate scientists countries, yields from rain-fed
Enigma Number 1587
Deja vu
And how many of the numbers L 2,3,
. . .
, N divide exactly into N? I've
SUSAN D E NHAM
worked out that number and I'll tell
I have in mind a number N. I'II tell you
you someth ing about it:
some things about it:
It is more than 2. lf you draw a
It is more than 2. lf you draw a
figure with that numbe r of stra ight
figure with that number of straight
sides, with all its angles the same,
sides, with all its angles the same
and with all the vertices lying on a
and with all the vertices lying on a
circle, then a l l the sides will be equal
circle, then all the sides will be equal
in length. And the angles will be
in length. And the angles will be
whole numbers of degrees.
whole num bers of degrees.
What is N?
WIN £15 will be awarded to the sender of the first correct answer opened
on Wednesday 21 Apri I. The Editor's decision is final. Please send entries to
Enigma 1587, New Scientist. Lacon House, 84 Theobald's Road, London WClX
8NS, or to
[email protected] (please includeyour postal address). Answer to 1581 Daley's Gold: The number is 103274
The winner Simon Searle, Nuneaton, Warwickshi re, UK
24 1 NewScientist 1 20 March 2010
Independent thinkers are unlikely to want or be able to join the club. So how could a renegade thinker respond to Thorpe's challenge to "bring forth a body of peer-reviewed evidence" to falsify an entrenched mainstream argument? How about inviting the peer review club to identify, or even advertise for, intellectual square pegs -and ask them to draw up their own menu of ideas from (27 February, p 24) is unconvincing which the peers could select a small proportion for support? and takes refuge in well-worn This would be democratic yet arguments. Publicly funded science is innately conservative. still open up the possibility The need to develop a career, to of uncovering valuable original thought. win the next grant and to seek approval from peers all mitigate Whitwell, Isle oJ Wight, UK against heretical thinking. There is no such person as a disinterested scientist: we all set Climate complacency up hypotheses we prefer to prove From Ben Haller, McGill University rather than disprove. Given that there is far-reaching groupthink I am perplexed by your attempt to put a spin on the environmental in science, simply turning over the membership of grant award problems we face. JohanRockstrom and colleagues report that we panels faster does little to challenge established thinking. have already exceeded the limits To suggest that "it is incumbent of sustainability in three areas on those who claim that the and are approaching limits in science is flawed to bring forward most others (27 February, p 31). a body of peer-reviewed evidence How on earth is this the "breath of that shows the hypothesis is fresh air" your editorial describes? false" is effectively to state I can only imagine that your positive take comes from that professional scientists can never be challenged -rather comparing environmental dangerous ground. problems with ozone depletion. This is not to deny the That, however, should not be any overwhelming evidence of cause for optimism. Ozone anthropogenic climate change, depletion was caused by a few easily identified and easily but science funders could do more to demonstrate how they replaced chemicals; was easy are encouraging healthy plurality to understand; and did not have and dissent. powerful lobbies such as the oil Dunmow, Essex, UK industry blocking action. Tackling climate change, on From Bruce Denness the other hand, will require huge changes, is extremely difficult to Alan Thorpe defends climate science on the grounds that understand, and has some of the scientific quality control is most powerful lobbies in the generally assured by peer review. world determined to maintain the status quo. He goes on to say: "The system is not perfect but it's the best one We are already over the brink for carbon dioxide emissions we have." But is it? What peer review guarantees and, apart from the scientific community, we are nowhere near is the attainment of mediocrity in the most efficient way. even reaching consensus that
For more letters and to join the debate, visit www.NewScientist.com/letters
there is a problem. We are obviously not responding to climate change in the way that we responded to ozone depletion. In your article you state that Rockstrom's findings show that we still have some "breathing space", and scold environmentalists who seek to "minimise all human impacts on the planet". But we have no breathing space and we are rapidly making the problem worse. You state that there is "no room for complacency", but your attitude sure sounds like complacency to me. Montreal, Canada
Sugaring the pill From Colin Jacobson Martin Robbins's article on homeopathy (30 January, p 22) shows that he understands almost nothing about it. Ifhe did, he would know that UK doctors using homeopathy cost the government considerably less than those who do not, and that the 40 per cent of French doctors who use homeopathy cost the French government less than half of those doctors who use conventional medicine. If homeopathy is as useless as he makes out, why have both the Word Health Organization and the European Parliament called for its closer incorporation into the western medical system?
The fact that homeopathy is increasing in popularity suggests that there is a very satisfied user base that globally saves their governments hundreds of
millions. The big drug companies are not happy about this, and have tried for decades to discredit homeopathy, though I am not suggesting that Robbins has any association here. As for arguments that homeopathy only works via the placebo effect, Robbins should talk to my 14-year-old dog. After months of conventional treatment for arthritis he could barely stand. Following a course of homeopathy he now joins me on a daily walk. Homeopathy is cheap, effective and safe and should be a complementary part of every good health care system. Kirribilli, New South Wales, Australia From Hilary Gee John Poynton (27 February, p 26) recounts an experiment on the inhibitory action of mercuric chloride on the enzyme malt diastase. He states that as the solution was progressively diluted, the rate of hydrolysis increased. Surely this is exactly as you might expect? If the concentration of inhibitor is reduced, there is less inhibition. What is not clear from Poynton's letter is whether he claims that rates of hydrolysis in the homeopathic dilutions increased to rates above that ofthe control treatments. That would indeed be worthy of note ifrepeated. Cartmell Cumbria, UK From Barbara-Anne Smith I don't understand why homeopathy attracts such antagonism. Presumably Martin Robbins would attribute any cures to the placebo effect. Is that such a bad thing? Surely it is preferable for someone to recover after swallowing a sugar pill than after taking effective drugs which may have undesirable side-effects. Falkirk, Scotland
Cave writing From Cynthia Newby Luce Your article "Messages from the Stone Age" (20 February, p 30) made me intensely frustrated. I've spent over 20 years trying to get academics to pay attention to such work. In the late 1980s I was working in Brazil. As a result of my own rock art research, I came to the same conclusions: that what most academics dismissed as "doodles" were actually meant to convey meaning.
I hope that all those people researching the origins of writing will take note and perhaps share ideas and results to shed more light on this fascinating and important subject. Santa Ana, California, US From John Ross The article on Stone Age symbols brings to mind a question I first asked myselfyears ago when I saw cave art in northern Spain; where did they practise? I studied and taught art for many years and I would be astonished ifthese pictures were somebody's first attempt. I assume they started out decorating objects and their own bodies and developed it from there - but how could we ever know? Nunwood, Dumfries, UK
NASA's main achievements have been launching, repairing and upgrading satellites such as the Hubble Space Telescope and sending probes to the far reaches of the solar system. It is true that the Apollo missions told us much about the moon, but this was mainly a cold-war exercise in one upmanship, with scientific knowledge as a spin-off. The two Mars rovers and the Mars orbiter have achieved far more than any crewed expedition could have dreamed of. Probes to Jupiter, Saturn and beyond have revealed more than any astronaut could, without the problems of keeping people alive in space for years. NASA has a bright future in front of it without sending people to the moon, Mars, an asteroid or indeed any other solar system object. What, apart from razzmatazz and an almost bottomless budget deficit, would such crewed missions accomplish? Sending ever-smarter probes into space is the sensible approach and will gain us the greatest insights. Poole, Dorset, UK
For the record • Wedid not mean to imply that
Green Mountain Coffee of Waterbury,
Vermont, uses the word "green" to suggest a wholesome image (20 February p 6). The company ,
takes its name from the Green mountains, which give the state its name and to which the company headquarters are close. Letters shou Id be sent to: Letters to the Editor, New Scientist 84 Theobald's Road, London WClX 8NS Fax:
Probes rule From Neil Seymour Why the obsession with astronauts (13 February, p 8)?
+44 (0) 20 76111280
Email:
[email protected] Include your full postal address and telephone number. and a reference (issue. page number. t itl e)
to articles, We reserve the right to edit letters, Reed Business Information reserves the right to
use any submissions sentto the letters column of New Scientist magazine. in any other format
20 March 2010 1 NewScientist 1 25
OPIN ION
Barefoot statistics Can statistics be wrested from the governments and corporations that pick u p the tab and reshaped to meet other needs? Lud i Simpson has a plan GOT something big to say? Grab a statistic, it lends authority. Most people know perfectly well that statistics can support different angles on the same story. But who has the time to put together the whole picture for themselves? In the UK, concern for the health of statistics - not least when it comes to statistics relating to health issues, such as patient waiting times, public·private health financing, and more has led to attempts to rescue the field from the spin of political and industrial lobbies. The UK Statistics Authority now oversees the production of official statistics independently of government, and is answerable only to Parliament. Straight Statistics, a pressure group oflegislators, statisticians and journalists, runs a website presenting statistics that have been "straightened out", having previously been twisted for political, business or personal advantage - a practice the organisation says is "widespread and often undetected". Partiality is deeply embedded in statistics. Data collection generally costs so much that little will be counted unless it is a government priority. This holds as much for questions in fundamental surveys such as the lo-yearly national census as it does for one-off inquiries. So it is not only the twisting of statistics that needs addressing butthe way they are produced. This is a starting point for the UK group Radical Statistics, which held its 35th annual conference in London last month. Among the highlights was a lecture by 26 1 NewScientist 1 20 March 2010
journalist and freedom of information activist Heather Brooke, best known for her work exposing the House of Commons' resistance to disclosing figures about the expenses claimed by its members. Another was provided by David Miller from Spinwatch, who outlined how the organisation's new website spinprofiles.org monitors public relations activities and spin in political and corporate life, and how supposedly independent institutes and disinterested experts are used as a front by vested interests to gain media coverage and policy clout. The audience and contributors were bound together not just by an
schools. Decades of work has shown beyond doubt that these divisive tables are statistically meaningless. Once standard errors of uncertainty are attached, the vast majority of schools are very similar. Only the extreme outliers remain interesting. The best use of the tables would be to screen for a few examples of best or worst practice, or ones which suffer from poor measurement. So what might statistics aimed at improving schooling achieve? In their recent book The Spirit Level, Richard Wilkinson and Kate Pickett argued that societies with the most unequal incomes have the worst health and most crime. If they are right, we might look to reduce inequalities between and within schools, and later at work. It's the same when it comes to employment. Figures purporting to measure unemployment tend to hide the full cost, not least by omitting people not claiming understanding of statistics: these state benefits. Statistical skills were people who produce and live could be applied to estimating how many of these missing by statistics, a diverse bunch of unemployed there are, and how researchers and commentators the figures are affected when who like what they do but don't governments change the rules. always like what is done with Worldwide, the tussle between their skills. Or what is not done with their skills: that is the extra statisticians' paymasters and ingredient. If current statistics are democratic need plays out in shaped by their funders' priorities, different ways, and arrangements for producing official statistics who will produce statistics to vary considerably. In Denmark fulfil other priorities - and what would those statistics look like? and Finland, for example, the national statistical bodies are Take the "league tables" that almost autonomous, while in rank the performance of UK the US they are under close government control. "Data collection generally Can the priorities underlying costs so much that little the collection of statistics be will be counted unless it is a government priority" changed? This is where it gets
Comment on these stories at www.NewScientist.com/opinion
interesting. What might a new statistics of social justice look like? And is it possible to convey the meaning of statistics to ordinary people without so many intermediaries, or is a different kind of intermediary needed? A commitment to using statistical skills in areas away from state or business agendas has taken Radical Statistics to all sorts of places. Its 2000 book Official Health Statistics: An unofficial guide was the product of a decade working with public-sectorhealth campaigns. And challenging official figures on immigration and nuclear weapons has been a big priority. We may not have transformed government practice, butwe have given confidence to voluntary campaigns and established statistical practice among new, usually receptive, audiences. Forays by Radical Statistics into local campaigns to define community needs or to challenge a school closure, say, have led us to pioneering grass-roots statistical education. This can involve going back to basics: doing away with computer power, and replacing it with people totting up questionnaire results. Some members now think "barefoot statisticians" practising in the community could prove a high point for our profession. Whether on employment statistics, official statistics independent of government, or meaningful performance statistics, Radical Statistics often lines up with majority thinking in the more formal Royal Statistical Society. Perhaps the lining up is in both directions: over 3S years, some angry young statisticians have risen to senior positions in the profession. However you look at it, the burning moral issues war, corruption, climate change and inequality - keep the search for radical statistics bubbling. •
One minute with ...
Bria n Cox The med ia-savvy British physicist tal ks about his o ld musical career, h is TV work and why science deserves decent fund ing
How d i d you get involved in rock music? When I was 18, I j oined the band Dare. We
reco rded two albums and toured with the l i kes of
Jimmy Page before we broke up in 1991. Ou r finale -
was like something out of This is Spinal Tap we
had a fight in a bar in Berl i n. Then I studied physics
at the U n ivers ity of Manchester and worked as a sound engineer for the band D:Ream before I
j oined the group in 1993. We had several h its, i ncl ud i ng a number one Things Can Only Get ,
Better, which the Labour party later used in its
1997 UK election campaign.
Do your peers resent you gadding about to make TV programmes? It's now widely accepted that science needs a
PROFILE
greater vis i bi lity and that it needs to become part
Rock star-turned-physicist B ria n Cox i s professor of particle physics at t h e U n i ve rs ity of Manchester, UK. H e also presents the new BBC TV series, Wonders of the SolarSystem
of popular culture. My colleagues also appreciate that I p ut my head above the parapet to make the case for science funding . Yo u have openly criticised t h e British government over the cash crisis facing the
proj ect called
Science and Technology Facilities Council
will hopefu lly result in additional part i cle
FP420 for several years, whi ch
(STFC), which funds the U K's astronomy and
detectors being installed very close tothe LHC
physics facilities. How do you feel about the
beams. I also study phenomenology: it's the
bridge between theory and experiment when
Labour government these days? I have bought back into the Labour dream to some
we research the ti ny bu i lding blocks of matter
extent after seeing the prospect of cuts com ing at
and the fu ndamental forces that operate between
us like an express train under the Tory pa rty.
them. I work on the LHC's Atlas detector and novel
Labour's science min ister, Paul Drayson, i s
ways to f i nd Higgs pa rti cles, which could he l p
probably the best we can have, thou g h Labour
expla i n th e o ri g i ns of mass. And I'm cu rrently
has made a bloody mess of the STFC. Overall,
wri ti ng a paper on u sing a process called vector
Labour hasn't done bad ly, though spending on
boson fusion to hunt for and measure the
research today is not much different from what it
properties of Higgs pa rti cles atthe LHC. It's
was under the Tories in 1985.
wonderful, speculative, blue skies scien ce.
Why are you so worked up over funding cuts?
In the light of your latest TV project which is
If you cut more than £500 m ill i on off the science
your favourite wonder of the solar system?
budget, it would do little short-term good and the
Satu rn's foggy moon, Titan. We had thought
-
potentia l downside is immense. I can t u ndersta nd
it was our least wonderful satell ite but now
it. To me boosting science fundi ng seems like a
we realise it looks so much like Earth, but with
'
good bet in pu re gambl ing terms.
methane instead of water: methane rain, snow,
ri ve rs and lakes. It became a mag i cal character
Ludi Simpson i s a convenor of
Do you have any time to do science?
in the TV series.
the Radical Statistics g roup,
At the La rg e Hadron Collider I ran a n upg rade
Interview by Roger H i ghfield
www.radstats.org . uk
20 March 2010 1 NewScientist 1 27
OPINION I NTERVIEW
From hippy icon to ecopragmatist Environmentalist, thi nker, mover, shaker, If it was "happening" i n the sixties and seventies, Stewart Brand
was there, Now he tells Liz Else why green i deology is
flawed and nuclear power and sl um s are good
IT IS a civilised plan: an afternoon with futurist, visionary thinker and all-round hippy icon Stewart Brand. This is a rare chance to meet the man who helped forge the counterculture of the 1960s and 1970S and infuse it with environmentalism. He was immortalised in the Tom Wolfe 1968 cult classic The Electric Kool-Aid Acid Test, a novel about Ken Kesey and the Merry Pranksters, a band of LSD-taking, magic-bus travelling, communal-living experimenters. Shortly afterwards, Brand published the giant sized WholeEarth Catalog, which set out to provide information or, as he termed it, "tools", for the millions of Americans then living communally or alternatively. Fast-forward to London 2010, and Brand is promoting his latest book, Whole Earth DiScipline. Unluckily, the local wine bar is noisy when we arrive, with a table full of post-prandial lawyers making conversation tricky. But Brand is unfazed: it will take more than a few drunks to dent the spry, sharp but genial public persona he has spent much of his 71 years cultivating. Then again, maybe there is something in the drinking water of supercool California where he has lived for decades - on a tugboat in Sausalito during the week, and at weekends in Petaluma, next PROFILE Stewart Brand set up the
CoEvolution Quorterly,
span ning natural sciences and culture, co-founded
The WELL (Whole Earth 'Lectronic Lin k), an online
community, and The Long Now Foundation, which .
promotes "slower/better" thi nking Whole Earth
Discipline is published by Atlantic Books and Viking
28 1 NewScientist 1 20 March 2010
to California's largest intact salt marsh. Zoning in past the noise, Brand is saying heart-warming things about London and New Scientist. Then come the bombshells. Nuclear power. Now. Slums good. At the back of my mind, the word "heresy" is half forming. But perhaps I should not be surprised by what to many may seem like a change of heart: after all, the subtitle of his new book is An Ecopragmatist Manifesto. He elaborates: "What would a green pragmatist do about the seemingly intractable issues we're facing? A pragmatist would say ideology doesn't help solve problems. Often it helps build loyalty, motivate people, helps people feel all warm about something, but it's not much help thinking through problems and coming up with creative solutions, most of which are usually against the ideology." The "Whole Earth" part is a conscious reprise of the sixties WholeEarth Catalog. The US edition even uses the black ofthe original cover plus the first-ever shot of Earth from an Apollo spacecraft. This time though it really does mean "whole Earth" - not "tools" Paul Ehrlich, published the best-seller The Population Bomb. "Within two years," for American drop-outs. "My book's big themes -climate change, urbanisation and Brand recalls, "the whole environmental biotechnologies - are all global phenomena," movement became the population issue. says Brand. "And 'discipline' is my way of They said, too many humans are the problem, trying to get people comfortable with putting therefore get rid of humans. Paul's view was ideology aside for a while." that we should put sterilising agents in the Surely not? Brand abandoning ideology? water. Well, Paul was wrong, but the green Old-style greens are clearly in for a bashing. movement valorised him and that's part of One of his big hates is "nature right, humans what we have to grow out of." It seems that the green movement wrong" thinking: nature, after all, is far from gradually became a politically conservative good, kind or efficient. So what changed him? The seeds were sown back in 1968 when force for Brand. But then with that jaw his biology teacher at Stanford University, dropper about sterilising agents still hanging,
For more interviews and to add your comments, visit www.NewScientist.com/opinion
goodness the world is chock-full of nuclear weapons," says Brand, "which we'd ideally love to take down to zero in the next decade or two. In the meantime, the US has been buying up the warheads of the former Soviet Union which used to be targeted at American cities, including my home town, Rockford, Illinois." As Brand points out, 10 per cent of American electricity now comes from power plants fuelled by decommissioned Russian nuclear warheads. Challenging stuff -and not without its critics, including long-time friend Amory Lovins, chief scientist at the Rocky Mountain Institute in Colorado, who attacked what he called the "four myths about nuclear energy" promulgated by Brand and others. These are: that renewables are unreliable; that
"Discipline is my way of getting people comfortable with putting ideology aside"
we are off again on a whirlwind tour. It's a bit like having AI Gore give you a personal lecture -from a rather different perspective but with just as many curve balls. In front of our eyes, shanty towns and favelas turn into burgeoning creative hubs. For instance, although Mumbai is more than half-slum, it is responsible for a sixth of India's GDP; women, subsistence farmers and children all do better there than in the villages. The real dark green shocker, though, is what will power the cities. It has to be fourth generation nuclear plants, says Brand. "What you do when resisting a whole industry is you
say, well, it's not like there's just one problem. There's waste, cost, weapons proliferation, there's a control problem and obviously that adds up to, 'Don't do it'. As an engineer, though, you take the whole issue apart and look at each aspect on its own merits." So while the Whole Earth Catalog advocated wind turbines, now Brand says: "To get a gigawatt capacity of electricity takes 250 square miles of wind farm. Holy smokes! And the wind farm is not on all the time so you're buying French nuclear energy or burning a hell of a lot of natural gas to make up the gap." And there's a bigger surprise. "Thank
there is insufficient land for renewables; that nuclear power is reqUired to reduce climate change; and that we need nuclear power as well as renewables. A new generation won't have this prejudice about nuclear power, says Brand. "There is an ageing green habit of being anti-technology which does not play with younger people. In nuclear energy you're seeing a generational shift. The online discussions in environmental forums are evenly divided because this community is mostly a 20S and 30S crowd." Sadly, younger generations have never heard anything optimistic about the world, says Brand of students he has lectured to. They were especially enthralled, he says, by the idea that in the future biotechnology could be used by anyone. And Brand's picture of teams competing at the Massachusetts Institute of Technology every September to create new organisms that do strange, wonderful, frivolous and useful things is beguiling. But before we part, he has a sympathetic word for older greens who have taken a "theological position" and are now seeing a lifetime of hard work slipping away. "In the book I didn't congratulate greens enough for their many extremely important successes, such as restoring wildlands and natural ecosystems services - and the large role in bringing climate change to people's attention." Build on the triumphs, he says, "so the other stuffwill feel more comfortable" for them. A truly ecopragmatic message .• 20 March 2010 I NewScientist 1 29
Cosmic lighthouses We once tho u g ht they were m essages from l ittl e g reen men. N ow p u lsars cou l d put Einstei n's relativity throug h its toug hest test, says Richard
30 1 NewScientist 1 20 March 2010
Webb
COV E R STO RY
relativity, gravitational waves are tiny ripples in the fabric of space-time. But they have proved frustratingly elusive, despite ever bigger and more expensive instruments being built to detect them. Pulsars could now pip these projects to the post - on a fraction of the budget. "We're already at the stage where we can start to rule out things," says George Hobbs ofthe Parkes Observatory in New South Wales, Australia, which is home to one of the pulsar-timing experiments. "We could make a detection next week," he says, depending on the nature of gravitational waves. It was August 1967 when pulsars first made Earth contact. In a field on the outskirts of Cambridge, UK, graduate student Jocelyn Bell and her supervisor Antony Hewish were using a new antenna array to scan the sky for radio sources. Back then, astronomical observations were measured in miles - of paper. Mechanical pens traced radio signals onto long charts, and it was Bell's job to trawl through them. In one chart, she spotted an odd bit of "scruff", as she described it: a train of pulses spaced 1.3 seconds apart. It did not fit with any astronomical phenomenon then known, and try as they might Bell and Hewish could find no explanation, natural or artificial. Stumped, they half-joked about who they should tell first that they had eavesdropped on little green men.
Relativity's predictions
N
IGHT in, night out, the rhythmic radio signals reach Earth. The slowest ofthem sound like a nail being hammered into wood, or a shoe being slapped against a post to rid it of mud. Others are more like a stuttering motor stopped at a traffic signal. Some make almost continuous tones, ripe to be combined into cosmic mood music. Always the same signature tunes, always from the same points in the sky. Small wonder that when astronomers first heard them back
in the 1960s, some thought theywere messages from alien civilisations. The signals aren't from ET, however; they are from pulsars. These extreme cosmic objects have been keeping us on our toes for over 40 years, and are poised for their greatest coup yet. Meticulous measurements of pulsars' timekeeping might just solve one ofthe biggest mysteries of modern physics: the whereabouts ofgravitational waves. The keystone of Einstein's general theory of
By the time they published their findings the following year, the true culprit had been unmasked: a neutron star (Nature, vol 217, p 709). These extraordinarily dense bodies, left behind when a star many times the size of our sun explodes in a supernova, pack the mass of our sun and more into a sphere just tens of kilometres across. "It is like taking a sewing thimble and jamming the population of the world into it," says Bell, now Jocelyn Bell Burnell ofthe University of Oxford. Besides being unusually dense, neutron stars also rotate rapidly and have huge magnetic fields. To turn a neutron star into a pulsar, its magnetic axis must be at an angle to its rotational axis. That way, the powerful jets of radiation erupting from the star's magnetic poles will sweep round as the star rotates, rather like the beam of a lighthouse. These jets are what regularly buzz our telescopes -although we still don't know exactly how they are formed (see "What makes a pulsar tick?", page 32). The first pulsars to be discovered spin in a comparatively leisurely fashion, taking > 20 March 2010 1 NewScientist 1 31
WHAT MAKES A PULSAR TICK?
" If both re lativity a nd g ravitational waves don't exist, our entire idea of how th i ngs came together i n the cosmos wi l l n eed a reth i n kll several seconds to complete one rotation. In 1982, however, a group led by Donald Backer of the University of California, Berkeley, upped the ante with a "millisecond" pulsar that whirls around a breathtaking 642 times a second, fuelled by matter and energy siphoned from a companion star. The pulses of millisecond pulsars are so fast and regular that they make fantastic cosmic clocks, rivalling the accuracy of any man-made atomic timepiece. From there, it is just a small mental leap to using them to spy out gravitational waves. According to Einstein's general theory ofrelativity, mass distorts space and time around it, creating the force we know as gravity. Not even massless light is immune to its embrace. General relativity's most outlandish predictions have been confirmed, including the existence of black holes and the bending of starlight by massive celestial objects. But one remains elusive. If two massive objects are in orbit around each other, relativity says their accelerations will cause transient distortions in space-time that ripple out into the cosmos -gravitational waves. So far, we have only one piece of 32 1 NewScientist 1 20 March 2010
We don't know why pulsars tick so regularly. The answer may lie in a paper presented in January to the American Astronomical Society meeting in Washington DC byJohn Singleton and
A similar effect shapes the sound waves
Andrea Schmidt ofthe Los Alamos National Laboratory in New Mexico. They suggest the tick might be something akin to the sonic boom produced by supersonic aircraft as they
observer on the ground as a single "boom" ( arxiv.org/abs/0912.0350). Singleton says his model can reproduce all the features of the radiation given out by a pulsar, replacing
accelerate past the speed of sound (arxiv.org/abs/090B.1349). Relativity does not forbid the magnetic fields atthe surface of a pulsar rotating faster than the speed of light,
the hotchpotch of models needed before. That has gotJocelyn Bell Burnell, who discovered pulsars, interested.
says Singleton. As they do 50, his team suggests, particles of opposite charge are pushed to either side of the pulsar, where they emit radiation. The pattern of radiation is then sharpened by the
explain, and very neatly," she says. Other theorists are less impressed, but Singleton says that is to be expected. "If we're right - and I'm
superluminal boom of the magnetic field into a sharply defined pulse that is emitted into space.
circumstantial evidence that such waves exist. It comes, fittingly enough, from a pulsar. In 1974, astronomers Russell Hulse and Joseph Taylor discovered one pulsar circling particularly tightly around a companion, completing one orbit every 8 hours. They saw the distance between the two bodies steadily diminish as they spiral in towards each other exactly what Einstein had predicted should happen if they were losing energy by radiating gravitational waves. Similar stellar two-steps have been going on throughout cosmic history, and have played a huge part in building today's universe. According to our best understanding ofgalaxy formation, small galaxies have collided and merged over time to forge bigger ones. Their central black holes must have merged too, to form the supermassive black holes present at the centre of most galaxies. As they did so, they should have whisked up the space around them, sending out gravitational waves that still persist today. Even built up over eons, this rippling of space-time is tiny, and the peak and trough of a complete wave can take years to pass a point in space. Inordinate patience and
emitted by an aircraft as it accelerates through the sound barrier. While the people inside hear a continuous rushing sound, the sound waves arrive at an
'They are explaining some features of pulsar emission that are difficult to
convinced we are - our model replaces 40 years of work that has employed hundreds of theorists. You would expect some hostility."
a super-accurate detector are needed to see anything. The biggest detector built so far is the Laser Interferometer Gravitational-Wave Observatory (UGO). Spread over two sites in Louisiana and Washington, it aims to nail gravitational waves by measuring changes in the time it takes a laser beam to zap up and down between mirrors set kilometres apart. So far it has seen precisely nothing. This is where millisecond pulsars come in. Pulsars lie many light years from Earth, leaving plenty of intervening time and space for gravitational waves to gently stretch and compress, so altering the time it takes for their pulses to hit Earth. Theoretically, all you need to see the effect is a single, bright millisecond pulsar that you can time sufficiently accurately for a few years. In practice, though, this effect is not large enough to be seen even with the brightest and best-timed pulsars. But there is a cunning workaround. As gravitational waves ripple out from their source, they stretch space-time in one direction and squeeze it at go degrees to this. Pulsar pulses reaching Earth that pass through a stretched area arrive unusually far apart, and those that pass through a squeezed
cosmic radiation. In January this year, the Fermi team announced that 17 new millisecond pulsars had popped up in just three months. It could be the breakthrough pulsar-timing needs. Not all the new pulsars will be suitable we already know that four are "black widow" pulsars, sucking mass from an unseen companion star. "That can lead to changes in the pulse arrival times as the radio waves interact with gas from the companion," says Ben Stappers, a member of EPTA. But with a few hundred unidentified Fermi sources still to be examined, a cornucopia of new millisecond pulsars is on the horizon. One characteristic of the Fermi pulsars Millisecond finds augurs well: they are pretty evenly spread Detecting gravitational waves using only across the sky, with many visible from the these pulsars is still possible; it will just take northern hemisphere. Compared with the longer. "More millisecond pulsars will make southern sky, the northern sky has, until our detections stronger and come earlier," now, been a pulsar desert - a situation that says Ransom. "We know they're out there, astronomers had been attempting to rectify we just haven't found them yet." with the first ever all-sky northern hemisphere pulsar search. Our luck is beginning to change, though. Ultimately, however, the best and fastest In June 2008, NASA launched the Fermi gamma-ray space telescope, a general-purpose results can only be achieved by pooling the telescope to rnap out sources of high-energy finest ofthe pulsars from north and south into one super-array. This is in the pipeline, too, with the three pulsar projects agreeing to share measurements and eventually coordinate observing time across the globe. So how long will it be before we have a definitive detection of gravitational waves? E i n ste in's n etwork Hobbs's prediction of next week is, he admits, We should be able to detect the presence of gravitational waves by timing the pulses on the optimistic side. "But with the data we from many mill isecond pulsars scattered around the sky already have, it should be within five years," he says. That puts pulsar-timing in a neck-and Gravitational waves, which gently radiation that passes stretch space-time in one direction neck race with LIGO, which by 2015 will have a compressed region of squeeze it in another, are l
area arrive closer together (see diagram, below). If we map out millisecond pulsars in the sky and time their pulses for long enough to find out the average time it takes them to reach Earth, any variation in that time would indicate interference from gravitational waves. See a pattern of variation in many pulses, all fitting the expected stretch-squeeze template, and you've hit gold. This is exactly what three projects are now searching for. First out of the starting blocks was the Parkes Pulsar Timing Array at the Parkes Observatory, which started work in 2005. It has been joined by NanoGrav, a North American collaboration that uses the world's most powerful radio telescopes at Arecibo in Puerto Rico and Green Bank in West Virginia. Completing the trio is the European Pulsar Timing Array (EPTA), which combines data from radio telescopes in Germany, the Netherlands, France, the Italian island of Sardinia and the UK. "To see a gravitational wave signal from supermassive black holes, you need to time twenty millisecond pulsars to 100-nanosecond accuracy with observations every two weeks for five years," says Hobbs. His team at Parkes
Earth, and a series of pulses
arrives further apart in time
has been observing pulsars for long enough unfortunately just not enough ofthe right kind of pulsar. "The lack of good millisecond pulsars has been the biggest problem for all the pulsar timing arrays," says Scott Ransom, a member of the NanoGrav team based atthe National Radio Astronomy Observatory in Charlottesville, Virginia. Until recently, we only knew of about sixty millisecond pulsars in our galactic disc, and not all of them fit the bill for gravitational wave hunting. Only half a dozen can be timed to 100-nanosecond accuracy, with many more at the 2oo-nanosecond to microsecond level.
between pulses is so regular we can use it as a n accurate clock
Richard Webb is a features editor at New Scientist
20 March 2010 1 NewScientist 1 33
Ca n we e l i m i nate the pests that ru i n c ro p s but leave thei r b enig n rel atives u n harmed? Bij al Trivedi explores a smart new strategy
It's a bug's death T
HE
environmental movement is often traced back to Silent Spring, the 1962 book in which Rachel Carson documented some ofthe harmful effects of pesticides on people and animals, and called for stricter controls. Half a century on, the book remains controversial butthere is now no doubt that however useful pesticides are, they cause an immense amount of damage too. Pesticide poisoning is a major health problem. Everyyear thousands of farm workers die of pesticide poisoning and millions more suffer severe effects, mainly in developing countries. A survey in Nicaragua last year concluded that 2 per cent ofthe country's adult population suffers pesticide poisoning annually. This kind of finding is not unusual. Then there are the environmental effects. Many pesticides are toxic to a wide range of animals, and dose is often the only factor that restricts the killing to insects. They kill beneficial insects alongside harmful ones, which means that once farmers start using pesticides they often have to keep using them because there are fewer natural predators to help control pest populations. Some pesticides persist in the environment for decades and accumulate up the food chain. Plants genetically modified to produce biodegradable insecticides such as Bt are one way to solve these problems, but this approach does not work for all pests and there is intense opposition to GM crops in many countries. Now, however, researchers are working on an entirely new generation of pesticides, one that promises to target individual species while leaving other animals unharmed. These could be sprayed onto plants like conventional pesticides or genetically engineered into crops. Already, one company is preparing for field tests of a spray targeting the Colorado 34 1 NewScientist 1 20 March 2010
potato beetle, a major pest (pictured, right). The key to the new pesticides is gene silencing, and RNA interference (RNAi) in particular. In 1998, it was discovered that when a double strand of RNA (dsRNA) matching the sequence of a particular gene is injected into nematode worms, that gene gets switched off, or silenced. RNAi may have evolved as a defence against viruses containing double-stranded RNA. Now, though, all plants and animals rely on RNA interference to help control the activity of their own genes. Remarkably, the effect can spread from cell to cell in some invertebrates: when dsRNA is injected into one part of the body, the matching gene often gets silenced in other parts ofthe body too. Just as surprising was the discovery that
ofthe light brown apple moth, a major pest in Australia and New Zealand, could be greatly reduced by feeding them dsRNA. A year later, two landmark papers published together inNatu re Biotechnology proved that the effect was strong enough to protect plants from pests (vol 25, p 1231). One team, led by James Roberts of Monsanto in Chesterfield, Missouri, first fed a variety of dsRNAs to western corn rootworm larvae to see if any killed them. They found the most effective RNA targeted a gene coding for the enzyme v-ATPase. Next, the team genetically modified maize to produce this dsRNA in its roots. The modified plants suffered less root damage when infested with rootworm. A second team, led by Xiao-Ya Chen, now head of the Shanghai Institutes for Biological
IIl nvasive pests are a serious problem genetic too l s that attack specific species wou l d make fo r ve ry powe rfu l wea pons" simply feeding dsRNA to worms could silence genes, although it was not as effective as injection. That result caught the attention of researchers like Steven Whyard, then working for Australia's national insect research institute, CSIRO Entomology, in Canberra. "We thought: it won't work in an insect, but let's give it a try anyway because ifit does work we're off and running with something rather interesting," he says. It did work, Whyard and his colleagues at CSIRO patented the method, and by 2006 its pesticidal potential was becoming clear. A team led by Richard Newcomb at Plant and Food Research in Auckland, New Zealand, showed that gene activity in the guts and the antennae
Sciences at the Chinese Academy of Sciences, tried a less direct strategy. Cotton plants produce a natural pesticide called gossypol. Pests like the cotton bollworm, however, have evolved resistance, and Chen's team has found that this resistance depends on an enzyme called cytochrome P 450. When bollworm larvae were fed plant material containing gossypol as well as dsRNA targeting the gene for cytochrome P450, the insects stopped growing and started dying. These studies generated a lot ofinterest, but big questions remained. One is the effect of dsRNAs on humans (see "Is it safe?", page 36), and the other concerns specificity. 1fthe dsRNA is designed to target a gene sequence that >
Colorado beetles will be among the first to face a new class of pesticides
20 March 2010 1 NewScientist 1 35
IS IT SAFE? Using gene silencing, or RNA interference (RNAi) to target specific pests while leaving
silence genes. In fact, the big problem for those trying to develop drugs based on
other species unharmed sounds like an enormous step forward. But can we be sure that the key ingredient - double-stranded RNA (dsRNA) won't have unexpected side
gene silencing is finding ways to get siRNAs into cells in the human body (New Scientist, 27 February 2009, p 15). So there is good reason to think sprays
effects in people? Although most RNA in cells is singlestranded, all plants and animals also produce dsRNA to regulate the activity of their own genes. "There are lots of dsRNAs in the
containing dsRNAs lethal to insects, or plants modified to produce them, will pass all the safety tests. However, if the RNA was altered in a way that allows itto get into human cells, perhaps by making it
plant and animal products that we eat every day," says Michael Czech, a molecular biologist at the University of Massachusetts
persist longer in the environment, it might cause problems. "If you modify the dsRNA by encapsulating it or changing the RNA
Medical School in Worcester, who is exploring ways to use RNAi to treat type II diabetes. "Those RNA molecules are rapidly chopped up by the enzymes in our gut and are non-toxic." There is also a second line of defence in
molecule - then you are imposing a new chemistry that could have toxic effects on humans," Czech cautions. If medical researchers ever devise an effective way to deliver siRNA orally, it might be possible to use it for controlling a wide range of animals. "If they can figure
-
the form of enzymes in our blood that break down dsRNA. "You could inject dsRNA into primates at moderate doses and nothing would happen;' says Daniel Anderson of
ways to deliver itto all organisms, then it could be used to control all kinds of invasive species," says Steven Whyard of the
the David H. Koch Institute for Integrative Cancer Research at the Massachusetts Institute of Technology, who is designing drugs based on RNAi. Even without these defences, the long
University of Manitoba in Winnipeg, Canada. As long as the siRNAs are carefully designed, only the target species should be affected. It's not much of a leap to wonder whether RNAi could also be abused to attack specific
dsRNAs used forkilling insects are difficult to transport into human cells and if they did get inside they could trigger an immune defence mechanism rather than shutting down specific genes, although it's not yet clear if this in itself might be harmful. In vertebrates, short pieces of dsRNA around 21 base-pairs long, called small interfering RNAs or siRNAs, are more easily used to
groups of people or even individuals. There have long been concerns about the misuse of RNAi. "Like any technology, it can be used for good or bad," says Whyard. "Yes, this technology could be used to target individuals, but I don't know how effective it would be. It's probably a whole lot more trouble than the current methods people use."
is unique to a particular species, then in theory that dsRNA should be harmless to other species. But this assumption had not been tested. Whyard, now at the University of Manitoba in Winnipeg, Canada, took on the challenge. First, he tried targeting four quite different species - fruit flies, pea aphids, red flour beetles and tobacco hornworms -via the gene for v-ATPase, which in the gut is a protein pump which controls acid levels. "If you mess that up, you will cause malfunctioning of the gut physiology and the insect may ultimately starve or die," says Whyard. Whyard designed four different dsRNAs, each one specific to the v-ATPase gene variant 36 1 NewScientist 1 20 March 2010
in one of the four species. When fed the dsRNA matching their genes, between 50 and 70 per cent of the insects died. When a dsRNA designed for one species was fed to the other three species, less than 5 per cent died. Next, Whyard tried to kill four closely related species of fruit fly ofthe genus Drosophila. This time he targeted a gene for gamma-tubulin, which is essential in cell division. When he fed the fruit flies dsRNA targeting their specific gene variant, between 35 and 55 per cent died. In contrast, a dsRNA designedfor one fruit fly species had little effect on a non-target species, killing less than 5 per cent. "I was quite pleased to see that," says Whyard. "Actually I was surprised."
Because there are so few differences in the sequences ofthe gamma-tubulin gene variants among the fruit flies, Whyard had expected more "off-target" deaths. As more and more genomes are sequenced, it might become possible to find genes that are only present in a single species. Targeting these would reduce the effects on other species still further, Whyard says. So far, though, his research is the only work of its kind. Much more needs to be done to prove dsRNA's effects really are species-specific. Whyard's work also shows that simply spraying dsRNA onto insects' food can be enough to kill them. Stored grains could be coated in dsRNA to protect them from pests like the red flour beetle, he suggests, although spraying it on crops like conventional pesticides might be a different matter. Devgen, a biotech company based in Ghent, Belgium, is ready to field test a spray containing dsRNA targeting the
discovered in California and feeds on a wide range of plants, would be tricky. The dsRNA would have to be coupled to some kind of bait to lure the moths, Carey says. It might not even be necessary to kill pests directly. "Ifyou silenced a pheromone receptor, you could block communication and mating," Newcomb points out. Interfering with the social structure of insect colonies could also curb populations, says Michael Scharf at the University of Florida in Gainesville, who has silenced genes in termites by feeding them dsRNA. He has shown that silencing a gene called HeX-2 triggers the transformation of workers into soldiers and thinks that boosting the number of soldiers might cause a termite colony to collapse. "The soldiers are the slackers in society," says Scharf. "So more soldiers is bad for the colony. The workers can't feed, clean and manage a colony that contains more than about 10 per cent soldiers." Non-lethal ways of controlling pests should, in theory, slow the evolution of resistance, which is becoming a massive problem with conventional pesticides and will also eventually happen with crops containing pesticide genes. Insects could acquire resistance to specific dsRNAs too, by evolving new variants of the gene that the dsRNA targets. But if this happens, the dsRNA could be changed to target the new variants. Such tweaks would be much easier and cheaper than developing new conventional pesticides. It would be rash to say resistance could be completely ruled out, however. "I'm always reluctant to say that insects won't mount resistance," says Whyard. "Insects have mounted resistance to everything we've "The pote ntial benefits/ a n d p rofits/ a re certa i n ly getti ng thrown at them so far:' Nevertheless, because the cellular machinery required for dsRNA attenti o n . Eve ry a g roche m ica l company in the U S is to silence genes is essential for normal i nterested in RNAi - ifs on everybody's ra d a r" development, mutations that block the effect of dsRNAs at a fundamental level should be lethal to the insect. Colorado potato beetle, though with patent It would also work onlyfor pests that eat the parts of the plant that are above ground. For and research papers pending, head of Other uncertainties remain, too. For technology development Geert Plaetinck will those like the corn rootworm, plants would example, the approach might not work for all only say that the spray looks very promising. insects, or even for all genes. One recent study have to be engineered to produce dsRNAs. The specificity of gene silencing means it Devgen has also investigated ways to kill found that feeding dsRNA to tsetse flies will could be especially usefulfor targeting invasive shut down a gene in gut cells but not in fat that much-despised household pest, the cockroach. It tried targeting seven genes and species, which are very hard to kill using cells. There may be many other complications found that silencing four of them individually conventional methods without causing a ofthis kind. Nevertheless, the potential benefits, lot of collateral damage. proved lethal. But -surprise, surprise - the roaches proved tough to kill, Plaetinck says, "I can't imagine anything better," says and profits, are certainly getting attention. James Carey, an entomologist at the University "Every agrochemical company in the US is requiring much higher doses of dsRNA than other insects. of California, Davis. "Invasives are a serious interested in RNAi - it's on everybody's radar," problem and tools that target specific species says Scharf. • Spraying will only be a viable approach could be a very powerful weapon." Still, if dsRNA can be cheaply mass produced, tackling widely dispersed invaders like the Bijal Tr i vedi is a freelance science writer based especially as the dsRNA will probably break in Washington DC light brown apple moth, which was recently down faster than conventional pesticides. Silencing crucial genes could kill
pests such as (clockwise from left) cotton bol lworms, pea aphids and tobacco hornworms
20 March 2010 1 NewScientist 1 37
--.
".!:......._ - -. _----
.. ..
• •
--
,
-..
�. .... �-
, ,
\
i
-
. ..-"� --
._ _..
---- ..----"
38 1 NewScientist 1 20 March 2010
\ ' \\,
\'--
- --- - -_ .. ..
� ,
..I
·
-
..
- _. - _ .-
\"
�
:
/....,/ ..
_ ___• __
...... . _ j�
,/
� __ O
\
'�
I,
.
/'
// �(
.
\ ",
"i
\ " \
", \ "
'-
-
V-
,
\
I
- -. - 7;' ,/
"" /\
i
\
Get enoug h of the rig ht b ra i n cel l s to ta l k about the sa me th i ng, and o ut pops consci ousness, An i l Ananthaswamy i nvestigates
,.
\ ::.:
\.
=
\i..J :;
'. /" ... I '.,
,
" S
;( \ \\ ... \.'Y.� \ ,,/ \, T�VEN LAUREYS will always remember � ."
...
I.
,
woman who had had a the\21-ykar-old \ I .,/ \, \ strofe, �he had been taken to a hospital ,/ it;} Liege, Be�i�m, where her condition She soon lost all motor Worsened rapIdly, \1 .� \ m6.:vemt;:.nt, ev�n the ability to open her eyes. Hei'prognosis looked bleak, so her doctors turne� to ��ur .ys, a neurologist, for a final opinio� befOre urning off her ventilator, By re·�.ording er brain activity as she was asked to 'respond to simple tasks, such as counting the nUlnber of times her name was spoken in a �rndom string offirst names, Laureys confirm�d that the woman was aware \\ of her surr.6undings, and so she remained on \. life supptrt (Neurocase, vol IS, p 271). Clearly 'tpat wl� the right decision: a year later she had
"" " '"
0"
I
�r,
\\// ·'(�J.I1'e 'global workspace'
./1h�egrates the senses into a /< si�'g�'e picture, filtering out confli� ting information" 10,"\
\\."
\
'.,
recovered enough to be discharged from hospital. "It was only technology that permitted us to show that she was conscious," says Laureys ofthe University of Liege. There had, however, been another clue to the patient's active mental state - too tentative to hold any weight in the diagnosis, but nevertheless significant. Laureys had observed a signature of coordinated neural activity, present in the resting patient, which seems to appear in the brain of anyone who is conscious. While such readings may one day provide a better diagnosis of coma patients, their ultimate implications may be even more profound, providing evidence for a 30-year old theory that claims to explain consciousness itself. Consciousness is one of neuroscience's long-standing mysteries. At its most basic, it is the simple question of why we become aware of some thoughts or feelings, while others lurk unnoticed below conscious perception. Is there a single module in the brain, a "seat of consciousness" if you like, that is responsible for awareness? Or is it a result of more complicated activity across a number of brain regions? Solve this, and we may be a little closer to explaining the more esoteric aspects of our complex internal experience. Now one theory that claims to do just that is rapidly gaining weight, with strong evidence from research such as Laureys's to back up its predictions. The idea, dubbed the global workspace theory, was first floated in 1983 by Bernard Baars of The Neuroscience Institute in
San Diego, California. He proposed that non conscious experiences are processed locally within separate regions ofthe brain, like the visual cortex. According to this theory, we only become conscious of this information if these signals are broadcast to an assembly of neurons distributed across many different regions of the brain - the "global workspace" (see diagram, page 40) -which then reverberates in a flash of coordinated activity. The result is a mental interpretation ofthe world that has integrated all the senses into a single picture, while filtering out conflicting pieces of information (see "Neural conflicts", page 41). Lack of compelling evidence left the idea langUishing on the shelf. Indeed, it took more than IS years for the theory to prove its mettle, when Stanislas Dehaene of the French National Institute of Health and Medical Research (INSERM) in Gif sur Yvette and Jean-Pierre Changeux ofthe Pasteur Institute in Paris updated Baars's model with the latest findings on the brain's wiring, Dehaene's group had already shown that distant areas of the brain are connected to each other and, importantly, that these connections are especially dense in the prefrontal, cingulate and parietal regions of the cortex, which are involved in processes like planning and reasoning. Considering Baars's theory, the team suggestedthat these long-distance connections may be the architecture that links the many separate regions together during conscious experience. "So, you may have multiple local processes, but a single global conscious > 20 March 2010 1 NewScientist 1 39
This time, volunteers were shown a number (the target), which appeared at one of four locations on a computer screen. After a random delay, the computer blanked out the original number and placed four letters around the original location. If the delay was less than 50 ms, the change becomes too confusing for the brain to process, and it cannot consciously detect the target. Any longer than 50 ms, though, and the subjects were aware of the target.
B roadcasting consciousness The global workspace theory suggests that consciousness arises from highly coordinated, widespread activity in the brain
CONSCIOUS
NON-CONSCIOUS
When signals are broadcast to a wider network of neurons across much of the cortex - the global workspace - we
localised, the associated sensations are not
become conscious of the sensation
perceived consciously
When signals remain
A signature of consciousness-
The team measured the subjects' neural activity with scalp electrodes as they completed the task. As expected, conscious perception coincided with a burst of activity in some of the regions implicated in the global state," says Dehaene. If so, the areas with roughly the same in both cases. Afterthat there workspace model, spanning the frontal, were stark differences. The neurons quickly especially dense connections would be prime parietal and temporal brain regions. What's stopped firing ifthe letters were perceived more, the researchers again found a 300 ms candidates for key regions in the global workspace. unconsciously. But when the subjects were delay between presenting the stimuli and The team put the theory to the test in 2005 conscious of the letters, the neurons in a witnessing this explosion of neural activity number of brain regions thought to be part (PLOS Biology, vol 5, p e260). by studying a neurological phenomenon of the global workspace, including the frontal known as "inattention blindness", where we This 300 ms delay is one ofthe theory's fail to see things that are before our eyes. They and parietal lobes, exploded into synchronous key predictions, since you would expect any presented their volunteers with two strings of activity (Nature Neuroscience, vol 8, p 1391). signals to take a while, relatively speaking, to letters in quick succession. In some instances, "Suddenly, your brain ignites with additional reach the different parts of the global they had to answer a question about the first activation, particularly in the frontal lobes, workspace, before we are fully aware of stimulus just after they had seen it, which perceiving something. when you are conscious," says Dehaene. caused them to miss the second string of letters Further evidence arrived last year, when This explosion of coordinated activity was just what Baars had proposed, corresponding Dehaene's team studied people with damage and only perceive them non-consciously. By placing 128 electrodes on their to the widespread "broadcast" of signals to their prefrontal cortex, which should volunteers' scalps, Dehaene's team teased disrupt the long-distance connectivity in the across the global workspace that he predicted out the differences in neural activity when global workspace. They would therefore take would accompany conscious perception. they were conscious ofthe second stimuli, Encouraged by this preliminary evidence, significantly longer to become conscious of and when it escaped their attention. For the Dehaene's team decided to put the global the information, as it would have to find its first 270 milliseconds the neural activity was workspace model through its paces again. way through alternative, longer routes. And
Consciousness, one neu ron at a time Rodrigo Quiroga at the University of Leicester, U K, may be famous for identifying the individual neurons that fire in response to the actress Jennifer Aniston, but his technique of using very small and precise electrodes to record the activity of single neurons has unearthed even greater treasures: patterns of single neuron activity that result in either non-conscious or conscious perception. Quiroga's team worked with people with epilepsy who were undergoing surgery to treat their condition. The researchers were interested in neurons in the medial temporal lobe (MTL), which is known to be involved in the
40 1 NewScientist 1 20 March 2010
transformation of perceptions into memories. Since you would expect conscious perceptions to be stored in long-term memory, the group suspected the MTL may be part of the global workspace network underlying consciousness. As with other such tests, the patients were shown a target image followed by a mask, another image that is meantto confuse the brain's perception of what it has just seen. Importantly, the delay between the target image and the mask controls whether the subject becomes conscious of the target or not. When the volunteers reported perceiving the image, Quiroga's team found that certain MTL
neurons fired about 300 milliseconds after the target stimulus. The same neurons never fired at that late stage when the stimulus was processed non-consciously (Proceedings of
the National Academy of Sciences, vol 105, p 3599). This all-or-nothing response of single neurons is predicted by the global workspace model, providing some of the strongest evidence for the theory. Although it's not yet known whether all the neurons in the relevent brain areas are roped into the global workspace, or just a subset, the ease with which Quiroga found them does at least suggest they are very prevalent.
that's exactly what they found, with the patients taking around 18 ms longer to become aware ofthe stimuli (Brain, vol 132, at the same time," says Baars. The global workspace model of p 2531). The same was true forpeople with This could have been a deal breaker for multiple sclerosis, who also have extensive consciousness, proposed by Bernard Baars Baars's theory, but luckily so-called binocular damage to their nerve connections, ofThe Neuroscience Institute in San Diego, particularly in the prefrontal cortex rivalry experiments provide good evidence California, argues that non-conscious (Neurolmage, vol 44, p 590). perceptions are processed in relatively small, that the brain does indeed actively select Compelling as these results are, the real local areas of the brain. It is only when this which information to send to our proof of the pudding for any theory in information is broadcast to a network of consciousness. Normally, both our eyes see neural regions, the "global workspace", that the same scene, so the brain can easily neuroscience comes from precise we become conscious of whatever it is that combine the two monocular inputs into a measurements ofbrain activity taken by electrodes implanted in the brain -the most we are experiencing. That, of course, relies coherent picture. But present the left eye accurate technique available. Such evidence with an image that's dramatically different on the ability ofthe brain to prevent arrived in 2009, when Raphael Gaillard, who conflicting messages from separate regions from what the right eye is seeing, and was working in Dehaene's lab and is now at the ofthe brain from being broadcast to the experiments have revealed the brain University of Cambridge, and his colleagues global workspace, which would confuse our resolves this conflict by allowing you to only see one or the other image at any one time. In picture of the world. "The reason why one took the opportunity to test the conscious perception of patients with epilepsy, who had needs a single coherent interpretation is other words, you are only conscious of either electrodes implanted in various regions of because you need to broadcast it, and you the left-eye image orthe right-eye image, don't want to broadcast competing messages but never both simultaneously. their brains as part of exploratory surgery. As in the previous experiments, brain activity during both conscious and unconscious perception was similar for the first 300 ms, followed by increased and If the global workspace really is essential for He cautions that neuroscientists have to coordinated activity in distant parts ofthe be "humble and honest" in their search for conscious perception, Laureys's team brain whenever something was perceived the neural basis of consciousness, since many predicted that the activity ofthe DMN should consciously. Crucially, although the electrodes be greatest in healthyvolunteers and in people questions remain. We still don't know the exact chain of activity within the global with locked-in-syndrome, who are conscious had been placed in areas relevant to the but can only move their eyes, and much less workspace, for example, or what information treatment of epilepsy - and not specifically areas proposed to be important in conscious active in minimally conscious patients. Those the brain regions are communicating to each other. "These neurons are electrical units in a in a vegetative state or in a coma should have perception - 68 per cent of the electrodes still even less activity in the DMN. chemical soup, and we have not yet decoded recorded a significant response to the conscious stimulus. This suggests that the their language," says Laureys. The researchers found just that when they Then there are the philosophical scanned the brains of 14 people with brain global workspace may in fact occupy a damage and 14 healthyvolunteers using fMRI. questions to consider. Philosophers like significant chunk ofthe cortex. It was the most compelling evidence yet David Chalmers at the Australian National In a paper published in December 2009, they University in Canberra, tend to divide the for the " signature of consciousness" predicted by the global workspace theory. Baars was study of consciousness into the so-called hard "Those with a higher level elated. ''I'm thrilled by these results," he said and easy problems. The easy problem looks at of activity in certain brain at the time. "It is the first really solid, direct correlations between brain activity and different states of consciousness - something evidence for the notion of conscious global areas will be the ones who the global workspace theory is beginning to access, or global broadcasting." More detailed recover from their coma" crack. The hard problem, meanwhile, probes experiments have supported these results by looking at the activity of single neurons (see the deeper question of how these patterns of "Consciousness, one neuron at a time", left). electrical activity could ever give rise to the showed that the activity ofthe DMN dropped Following these advances, researchers like many subjective facets of our internal life that exponentially starting with healthy Dehaene and Laureys are now attempting to volunteers right down to those in a vegetative we experience as conscious human beings. ask more nuanced questions thrown up by state (Brain, vol 133, p 161). "The difference Indeed, philosophers like Chalmers remain the global workspace theory. An important unconvinced that we are even close to between minimally conscious and vegetative approaching a solution to the hard problem. question from a clinical perspective, state is not easy to make on the bedside and for example, is how the signatures of Dehaene, however, predicts that it will all fall four times out of 10 we may get it wrong," he into place once we have a comprehenSive says. "So this could be of diagnostic value." consciousness might differ between people with brain damage and the healthy population. Even more important, Laureys thinks that a global workspace theory to work with. "Once person's DMN could one day determine their Laureys thinks he has some answers. the easy problem is solved, there will be no Certain regions of the brain's global prognosis. "I'm predicting those with a higher hard problem," he says. • workspace, dubbed the default mode network level of DMN activity will be the ones who will (DMN), are active even when we are resting Anil Ananthaswamy is a consulting editor for recover from their coma, or vegetative states, and not concentrating on any particular task. New Scientist or minimally conscious states," he says.
N e u ra l confl icts
20 March 2010 1 NewScientist 1 41
The ma n who sees the futu re Bruce Bueno de M esq u ita has been pred icti ng the futu re and getting it right for 30 yea rs. What's h is secret, asks
Sanjida O'Connell
M
y
HOROSCOPE this week says that now is the perfect time to relocate, or at least de-clutter. I know it s nonsense, but I can t help wishing there was a genuine way to predict the future. Perhaps there is. One self-styled "predictioneer" believes he has found the answer. Bruce Bueno de Mesquita is a professor of politics at New York University and a senior fellow at the Hoover Institution at Stanford University in California. In his new book, The Predictioneer (The Predictioneer's Game in the US), he describes a computer model based on game theory which he - and others - claim can predict the future with remarkable accuracy. Overthe past 30 years, Bueno de Mesquita has made thousands of predictions about hundreds of issues from geopolitics to personal problems. Overall, he claims, his hit rate is about go per cent. So how does he do it? Bueno de Mesquita's "predictioneering" began in 1979 when he was on a Guggenheim fellowship writing a book about the conditions that lead to war. He had d esigned a mathematical model to examine the choices people could make and the probability that their actions would result in either diplomacy or war. Like any model, he needed data to test it. A good opportunity arose when the US State Department asked his opinion about an ongoing political crisis in India. The ruling coalition had become unstable and it was clear that Prime Minister Morarji Desai would be forced to stand down and a new prime minister chosen from within the coalition. '
'
42 1 NewScientist 1 20 March 2010
Since his PhD thesis had been on Indian politics, and data on politics didn't seem a million miles from data on war, Bueno de Mesquita agreed to help. He compiled a list of all the people who would try to influence the appointment of the next prime minister, what their preference was and how much clout they had. He fed this information into his computer programme, asked it to predict how the negotiations would play out and left it to run overnight. His own hunch was that the deputy prime minister, Jagjivan Ram, would take over. Many other experts on Indian politics thought the same thing. The following morning, he checked the computer and found to his surprise that it was predicting a politician called Chaudhary Charan Singh would be the next prime minister. It also predicted that he would be unable to build a working coalition and so would quickly fall.
Strange result When Bueno de Mesquita reported the result to an official at the State Department, he was taken aback. The official said no one else was saying Singh and the result was strange, at best. "When I told him I'd used a computer programme I was designing, he just laughed and urged me not to repeat that to anyone," says Bueno de Mesquita. A few weeks later, Singh became prime minister. Six months on his government collapsed. "The model had come up with the right answer and I hadn't," says Bueno de Mesquita. "Clearly there were two possibilities: the model was just lucky, or I was on to something." Three decades later, it is clear that Bueno de Mesquita is on to something. The model has been used by Bueno de Mesquita, his students and clients (including the US government) to make thousands of predictions published in hundreds of peer-reviewed publications. These include whether or not North Korea's supreme leader, Kim Jong II, would dismantle his nation's nuclear arsenal, how a land-for peace formula could work in the Israeli Palestinian conflict, and which clients of a risk-management group were likely to commit fraud. According to research by the CIA, Bueno
de Mesquita's model is more than 90 per cent "1 can predict events and accurate (British Journal ojPolitical Science, decisions that involve vol 26, p 441). He now spends a considerable proportion of his time running a consultancy negotiation or coercion, firm based in New York. How is such accuracy possible? What Bueno cooperation or bullying" de Mesquita is not doing is predicting random events such as lottery draws. Nor does he claim formulation was based on games where to be able to forecast the movement of stock players tried to anticipate other players' moves or countermoves but essentially all markets, the outcome of general elections participants were cooperative and truthful. In or the onset offinancial crises - events where the 1950s, mathematician John Nash, subject millions of people have a small influence, but none is able to move the market on their own. of the film A Beautiful Mind, created a more realistic formulation in which players are out Rather, he confines himself to "strategic situations" where relatively small numbers for themselves and can bully, lie, bluff or of people are haggling over a contentious renege on their word to achieve their desired outcome. The classic example is the prisoner's decision. "I can predict events and decisions dilemma (see "Game theory in action", below ) . that involve negotiation or coercion, cooperation or bullying," he says . That Bueno de Mesquita uses Nash's assumptions: includes domestic politics, foreign policy, players are motivated by self-interest and will conflicts, business decisions and social do whatever they can to get what they want interactions. or at least to block an undesired outcome. His main tool is game theory, which uses In its simplest form the model works like mathematics to predict what people will do in this. First, Bueno de Mesquita decides what question to ask - for example, will Iran build a situation where the outcome also depends a nuclear warhead. He then compiles a list of on other people's decisions. "It's a fancy label everybody who might influence that decision, for a pretty simple idea: that people do what they believe is in their best interest," says and assigns each ofthem a value from 1 to an arbitrary number, say 100, in each offour Bueno de Mesquita. Invented in the 1940S by John von Neumann categories: what outcome they want; how > important they think the issue is; how and Oskar Morgenstern, the original
GAM E T H E O RY IN ACT I O N The classic example of a problem in game theory is the prisoner's dilemma. It was formulated in 1950 to illustrate a situation where cooperation is the best pol icy overall
remain silent and your partner confesses, he will go free and you will go down forlO years. If you both confess, you will both be sent to prison for 5 years. If both of you stay silent
but is trumped by raw self-interest, leading to a less-than-ideal outcome for everybody.
the prosecutor will rustle up some lesser charge and you'll each do 6 months. Neither
It goes something like this. You and your partner in crime have been arrested and placed in separate cells. You are
you nor your partner will learn what choice the other has made until after you have both announced your decision. The dilemma is that. whatever your partner does, you're better off confessing. So the rational choice is to confess. But when
each offered the followi ng deal by the prosecutor: confess, or remain silent. If you confess and your partner remains silent, all charges will be dropped against you and your partner will go to prison forlO years. If you
you both confess, the outcome is far worse than if you had both remained silent.
20 March 2010 1 NewScientist 1 43
determined they are to reach agreement; and how much influence they have. At that point, the "negotiations" begin. Say there are five players, A, B, C, D and E. To arrive at a result, every player is paired with every other and their positions compared. When A is paired with B, for example, A must decide whether to support or resist the central proposal ("Iran should build a nuclear weapon") or offer a counter-proposal, taking into account B's position and the likelihood of getting C, D or E's support. B either agrees, negotiates or bullies in return, all the while taking the positions of the other three players into account. Once every possible combination has been played out, each player sorts through the various proposals or demands they received, and evaluates the credibility of any threats made against them. Players may then shift position accordingly. At the end, the model calculates the group's overall position as a number between 1 and 100. This is taken to be the "result". When five players are involved there are 120 possible interactions - every player's interaction with every other, in both directions (5 x 4), multiplied by the other three players' positions (3 x 2). But the complexity soon skyrockets. If you jump to 10 players there are 3.6 million potential interactions. A typical predictioneer problem involves 30 to 40 players, although Bueno de Mesquita has
tackled problems with more than 200. Game theory aside, one of the key determinants of the model's success is the q uality of the original data: garbage in leads to garbage out. To obtain good quality data, Bueno de Mesquita consults widely with experts in the field. According to political scientist Nolan McCarty of Princeton University, this is the real strength of the approach. "I suspect the model's success is largely due to the fact that Bueno de Mesquita is very good on the input
"The old model was accurate 90 per cent of the time; the new one blows it out of the water in terms of accuracy" side; he's a very knowledgeable person and a widely respected political scientist. I'm sceptical that the modelling apparatus adds as much predictive power as he says it does." McCarty's Princeton colleague, economist Avinash Dixit agrees, but adds a word of warning. "Experts can be wrong, as we have seen in a different context recently, namely the financial crisis." Dixit has another problem with the data produced by the model. "There's ambiguity about what the final number means. For
Charan Singh becomes India's prime minister in 1979; Clinton takes office in 1993 hoping to reform healthcare 44 1 NewScientist 1 20 March 2010
example, if the prediction is whether Iran acquires nuclear weapons, and the answer is graded on the scale from 0 to 200, what would 120 mean? There's going to be a bomb or there will be no bomb? That is not so clear. I think the seemingly precise answers are deceptive, and game theorists should be more humble and more open about the uncertainty that is unavoidable in their calculations and results." Bueno de Mesquita accepts that the results require expert interpretation, but says there is no ambiguity. "The issue scales are not just whether a bomb will be built or not," he says. "Rather they define points in between; 120 on the Iran nuclear scale refers to Iran developing weapons-grade fuel but not building a bomb." Bueno de Mesquita is now working on a new and more complex model using Bayesian game theory, which also takes into account players' beliefs about other players and also allows for scenarios with imperfect or incomplete information. "The old model -essentially a sophisticated version of the one I used in 1979 was accurate 90 per cent of the time," he says. "This new model blows the old one out of the water in terms of the result and the accuracy of the path leading up to the outcome." In February he presented a paper at a meeting of the International Studies Association detailing the difference in performance between the two models. -
So how good is the new model? Bueno de Mesquita recently used it to make a prediction on the political situation in Pakistan. Working with a group of students, he asked how willing the Pakistani government would be to pursue Al-Qaida and Taliban militants in its territory, and how the US government could exert influence on their decision.
Targeting terror In January 2008 the students fed in data on all the players, including the US, Pakistan's then president Pervez Musharraf and other leading Pakistani politicans. Their assumption was that the US would offer foreign aid to persuade Pakistan's leaders to target the terrorists, and Pakistan would try to extract the maximum amount of aid possible from the US. The model predicted that to get maximum cooperation from Pakistan, the US would need to donate at least $1.5 billion in 2009, double the projected 2008 figure. In return for this Pakistan would pursue the terrorists on a scale of 80 out of 100, but no more. In other words, the leadership would make considerable effort to reduce the terrorist threat but not to completely eliminate it. "The Pakistani government are no fools," explains Bueno de Mesquita. "They know that the money will dry up if AI-Qaida and the Taliban are destroyed. So they will rein the threat in and reduce it,
"The Pakistani government are no fools. They know the money will dry up if the militants are destroyed"
2050. Depressingly, he predicts that although the world will negotiate tougher greenhouse gas reductions than in the Kyoto protocol, in practise these are likely to be abandoned as Brazil, India and China rise in power in relation to the European Union and the US. The predictioneer has also been but not utterly destroy it." spectacularly wrong, though. In 1992, he was The outcome? According to Bueno de asked to predict which bills would be likely Mesquita, the US government authorised to get through the US Congress after Bill $1.5 billion in foreign aid to Pakistan in 2009, Clinton was elected president. It was well and the Pakistani leadership sustained pursuit known that Clinton was planning to push ofthe militants at that level. "We have done through a healthcare bill, but all 27 of Bueno de Mesquita's predictions ofwhat was likely to very well," says Bueno de Mesquita. With such a powerful tool at your be in it and which elements would be passed disposal, it must be tempting to use it for by Congress turned out to be incorrect. yourself. Bueno de Mesquita admits that he Where did it all go wrong? The problem has received a few shady offers. In 1997, was with the inputs. Bueno de Mesquita had representatives ofMobutu Sese Seko, the assumed that an influential congressman, recently deposed president of Zaire (now Daniel Rostenkowski, would be the key to the Democratic Republic of the Congo), asked getting healthcare reform through. But just as Clinton began to push through the plan, him to calculate how to salvage control ofthe Rostenkowski came under investigation for country in return for 10 per cent of Mobutu's substantial wealth. Bueno de Mesquita alerted corruption and was eventually forced to resign from office. Bueno de Mesquita was unhappy the US government. at the time, but now shrugs it off: "I have been He has, however, used his model to help friends and also to assist the San Francisco willing to put my reputation on the line and Opera when it was having financial publish before events happened. So far I've not difficulties. been too embarrassed." • So what of the future? Another of Bueno de Mesquita's recent predictions addresses the Sanjida O'Connell is an ed ito r in New Scientist's future of climate change negotiations up to o p in i on secti on
Pakistan ups its campaign against radical Islam; I ra n attempts to join the
nuclear club 20 March 2010 1 NewScientist 1 45
BOOKS & ARTS
Ta ki ng a byte out of the u n iverse This book claims the u n iverse i s a com puter. That is not metaphor, it's hard science, says Seth Lloyd that operate using quantum bits (or qubits), such as those stored quantum information by Vlatko Vedral, on individual electrons, inherit Oxford U niversity Press, $29.95 this weirdness: bits can read 0 and WHAT is the 1 simultaneously, and quantum universe made of? computers can solve problems classical computers cannot. Over Matter or energy? Particles or strings? the last two decades, a flourishing field of quantum information and According to computation has generated a physicist Vlatko Vedral's appealing wealth of experimental and theoretical tests ofinformation new book, it is made, at bottom, of information. processing at the quantum scale. Vedral is one of the luminaries In other words, ifyou break in this field. the universe into smaller and smaller pieces, the smallest In Decoding Reality, Vedral argues that we should regard pieces are, in fact, bits. With this the entire universe as a gigantic theme in mind, Vedral embarks on an exuberant romp through quantum computer. Wacky as physics, biology, philosophy, If rea l ity is made of information, then religion and even personal finance. By turns irreverent, the universe is computing th e world erudite and funny, Decoding Reality is - by the standard of books that require their readers to know what a logarithm is a ripping good read. A bit is the tiniest unit of information. It represents the distinction between two possibilities: yes or no, true or false, zero or one. The word "bit" also refers to the physical system representing that information: in your computer's hard drive, for example, a bit is registered by a minuscule magnet whose north pole can point up or down. Any system that has two distinct states can act as a bit even an individual elementary particle: "electron over here" represents zero, "electron over there" represents one. When the electron goes from here to there, the bit flips. At this smallest of scales, however, the universe is governed by the famously weird laws of quantum mechanics. Computers Decoding Reality: The universe as
46 1 NewScientist 1 20 March 2010
that may sound, it is backed up by hard science. The laws of physics show that it is not only possible for electrons to store and flip bits: it is mandatory. For more than a decade, quantum·information scientists have been working to determine just how the universe processes information at the most microscopic scale. Starting in 2000, in a series of papers published in Nature, Science and PhysicalReview Letters, my colleagues and I were able to quantify the exact information processing capacity ofthe entire universe. Indeed, many ofVedral's arguments closely, and no doubt unconsciously, follow those of my 2006 book Programming the Universe. Unwitting rediscovery is the
sincerest form of flattery. In general, the parts of Decoding Reality that deal with quantum physics and quantum information are the least originaL Moreover, for an expert in the field, VedraI makes inexplicable and significant errors: for example, he misreports by more than 20 orders of magnitude the well-known figure for how many bits of information can be contained in the universe. More rewarding are the sections in which Vedral leaves the confines of his own discipline to speculate and expound on the role of information in biology, finance and philosophy. For example, his exposition of the relationship between computation and genetic information processing in living systems possesses a clarity and elan that rarely appears in scientific writing for a general audience. While it might not make you rich - despite what Vedral coyly suggests - his treatment of the relationship between investment theory and information theory is a pleasure. Finally, Vedral holds out hope for those readers who wish to entertain the notion of a relationship between the paradoxes of quantum mechanics and Vedic philosophy. Not since David Deutsch's magisterial The Fabric ofReality has a physicist given us such a wide-ranging and intriguing picture of how quantum mechanics constructs the world. • Seth Lloyd is director ofthe W. M. Keck Foun dat i on Center for Extreme Quantum Information Theory at the Massachusetts Institute of Technology and author of Programming the Universe (Knopf Doubleday, 2006)
For more reviews and to add your comments, visit www.NewScientist.com/books-art
Life su pport We'll need more evidence than this to make the case that entire ecosystems evolve
The Ptarmigan's Dilemma: An exploration into how life organizes and supports itself by John Theberge and Mary Theberge,
McClelland & Stewart. $28.95
Reviewed by Bob H ol m es
FIELD ecologists make great storytellers, and John and Mary Theberge are no exception. During more than 30 years of research, the pair have cut a wide swathe: from watching grizzly bears in Alaska to recording birdsong in the North American forests to taking a census of jackals in Africa, and much in between. This book is a compilation of what they have learned about the natural world along the way.
Their tales of where they have been and what they've done are easily the best parts of the book, full of wit and eloquence and a deep love for the outdoors. You'll go with the couple as they track caribou in eastern Canada during the spring melt, when the deep, wet snow and meltwater puddles require them to wear hip waders with snowshoes attached. You'll hike with them through drifts of dead Monarch butterfly wings on the forest floor in Mexico after an unexpected frost wiped out an entire population. You'll feel their angUish as a well-loved mountainside in Alberta is cleared to build a ski resort. These stories punctuate and add colour to what is essentially a textbook account of introductory ecology. If you have never been exposed to the subject,
this isn't a bad way to start, as the Theberges' anecdotes and, for the most part, avoidance of jargon help keep things from getting too dry. But for anyone with even a passing familiarity with the subject, there's little here to surprise. That's a bit disappointing because, as their book's subtitle suggests, the Theberges are after bigger game. Life, they argue, is an emergent property not of individual cells but of whole ecosystems, as no organism can survive without an ecosystem that provides food, water and other necessities. If they are right, then ecosystems are even more wonderful things than most of us realise - and more deserving of our respect and protection. The idea that evolution shapes and tunes ecosystems as a whole has intuitive appeal, though most biologists would shudder at this thought. To convince the sceptics, the Theberges will need to build a stronger case than the few hints and conjectures they offer here. Though they make the claim that ecosystems are more than the sum oftheir parts, the opposite might be said oftheir book.
Power to the people The Battery: How portable power sparked a technological revolution by Henry Schlesinger, Smithsonian Books, $25.99 Reviewed by M i c h ae l Brooks
BATTERIES get a bad press. They are always flat when you need them, or too heavy and cumbersome. Rarely does anyone .... .... . =. _ ..... appreciates just how wondrous an invention the battery is: the miracle of electricity in a handy package. And talk about power. The tale of the humble battery tracks the story ofthe modern world. After reading Henry Schlesinger's enthralling book you will struggle
to name an aspect of our lives in which the battery has played no part. Who knew that batteries helped establish the Reuters news agency, that nights spent in a battery room kick-started Thomas Edison's career, or that women used to wear battery-powered chastity belts -the forerunner of the modern rape alarm? You are probably within a metre of a couple of batteries right now. If you are curious about how they got there, this engaging biography of an essential piece of technology is a great place to find out.
Nature's GPS The Natural Navigator by Tri sta n Gool ey, Virgin, £14.99 Reviewed by Clint Witchalls
ANOTHER week, another news story Tho about a driver led Natural Navigator astray by their car's satellite navigation " system. What is �._iII::" remarkable about ••••• these stories is not that satnavs make mistakes, but that the drivers ignored what their eyes and ears were telling them and blindly followed the advice of an automated voice, even as it guided them into a field or to the edge of a cliff. As we become ever more reliant on GPS systems, the art of navigation is being lost. Tristan Gooley wants to do something about it. The Natural Navigator is full of advice on how to read nature's signposts: the sun, moon, stars and land. Gooley has flown and sailed, solo, across the Atlantic; in fact, he is to date the only person to have done both. But The Natural Navigator is not just for daring explorers. Even if most of us are unlikely to have to navigate a wilderness, learning to read nature can enhance a walk in a city park or a stroll along the beachfront. Read this and you will never look at the sky or a tree the same way again. 20 March 2010 1 NewScientist 1 47
For more feedback, visit www.NewScientist.com/feedback
FEEDBACK
nea rest toilet bowl everywhere you
ends up being eaten as food by the
go, a n d no more sti cki ng yo u r head i n
nation's inhabitants."
a disgusting, smelly garbage can."
"My question," Nancy says, "is how much phosphate fertiliser do
How thoughtfu l .
they think we should be eating?" T H E folders i n J i m Sullivan's Microsoft Outlook Inbox are
"DON'T kiss them, they're not
usually arranged by date
prin ces," warns a report from the
"Today", "Yesterday", "Last Week", " 2 Weeks Ago" and so on.
us Department of Health Ii! Human
One day last month, however,
the folders were labelled "Three " Months Ahead", 2-3 Months
editors are apt to change, such as
excited to be told that there is a
moving walruses to Antarctica to
new magazine for children on sale
im prove a layout or inserting a pet
report. "The Centers for Disease Control and Prevention says it's
i l l because o f pet frogs, especially
any - least of all any that gave him
African dwarf frogs. People have
the following week's winning
been getting salmonella, which
lotto numbers.
can lead to d iarrhoea, fever and
The next day things were
after i n fecti o n ." Frog fanciers: you have been warned.
glitches happen, so he isn't
Christopher Marlowe faked his
particularly fazed by this - but he
the flyer, entitled " E co bulbs,
death. Elsewhere on the same site
remains at a loss to understand
money saver?". This unexpectedly
(bit.ly/nohedgehogs), an author
why a Microsoft software designer
veers off into fundamental- and
reports that her references to
would choose to create folders for
indeed novel - theories of the
hedgehogs and free-standing
emails from the future and leave
nature of light itself.
wardrobes being removed for fear
them hanging around to pop up
of upsetting potential purchasers.
from time to time.
We suspect the hand of an unsure editor here too.
the colours ofthe rainbow," we
AND what were the iPhone software
are informed. Albert Einstein,
designers up to when they got to
apparently, "theorised that light
BARF in style. Feedback salutes
work on b i rth dates? Eve Ousby
can create particle-like entities
a Canadian outfit ca lled Morning
noticed the i Phone will a l l ow such
called photons" and thes e " throw
Chi cness Bags for its appeal to a very
dates stretching back to AD 1 and
off energy". Counting the number
particular niche market.
forwa rds a l o n g way beyond
of ways this is wrong is left as an exercise for the reader. Feedback regularly hears
"Are you pregnant a n d sufferi ng from morning sickn ess?" it asks. If so, the floral designs a n d pastel
abdominal cramps up to 72 hours
back to normal. Jim is aware that
theory that the playwright
when it travels fast it splits into
heari ng about more people becom i n g
in them, but sadly there weren't
in the UK, called How It Works. But
about it behaving like a wave,
"Frogs are not princes, a n d they c a n cause sickness," says the
Week", "Tomorrow" and "Today".
then he read the sample article on
" Most theories in physics talk
epidemic of frog kissing.
Ahead", "Next Month", "Next Excited, he looked for messages
INITIALLY, Richard Mallett was
Services i n response to an apparent
2010;
FINALLY, how's this for an inappropriate company name?
Eve says cramp of the thumb set in
Simon Sherrin couldn't quite
when she reached AD 31B6.
believe it when he saw a truck
Dates in the not-too-distant future
emblazoned with "Sweeney Todd
confirmation that non-fiction
colours of its "compact. d isposable,
could be useful for new arrivals. "And
Medical Waste Disposal" pass in
children's publications are
affordable, and yet stylish vomit
maybe some devout Christians would
Collingwood, Victoria, Australia.
something that, like sausages, you
bags" could be just the thing for you.
like to have Jesus on their contact
He figured he must have misread
Carry "a c h i c morning sickness bag
list," she sugg ests. "But is it really
it, but no, a quick web search took
don't want to watch being made. As some hard-done-by writers
everywhere you go", the company
necessary to have such an extensive
him to sweeneytodd.com.au.
range of birth years?"
The company boasts of using
report in a UK National Union of
exh orts. "You n o l o nger have to use
Journalists' article "Telling lies to
a i rsickness bags from the airplane,
"the latest in world-class medical
children" (biUy/liestochildren),
plastic shoppi n g bags or garbage
waste disposal technology".
whatever the authorwrites,
bags. You can stop searching for the
COINCI DENTALLY, the trade
Presumably that includes
association Meat & Livestock
discarded razors and the like?
Australia publishes a magazine
A recru itment agency i n central London a n n ou n ces: '7.5 ton n e del ivery d rivers
wanted". David Ll oyd hopes this is not a result of a l ifetime at the wheel
56 1 NewScientist 1 20 March 2010
called Feedback. Nancy Graham tells us she was intrigued by an
You can send stories to Feedback by
article in it discussing a report
email at
[email protected].
on phosphorus that asserted:
Please includeyour home address,
"A scant 2 per cent of phosphate
Th is week's and past Feed backs can
applied as fertiliser in Australia
be seen on ourwebsite,
Last words past and present plus questions, at
THE LAST WORD
Salt assault We heard that a bowl of Epsom salts placed near a microwave orTV reduces microwave emissions, and these cause the crystals to turn to powder over time, This sounds like a n urban myth, but we tried it. To our surprise, the salts turned to powder within a week or two, Why does this occur? Are microwaves really involved? • Epsom salts are magnesium
sulphate heptahydrate, MgS04,7HP, which is more than half water by weight. This means that they can absorb microwaves of the wavelength used in microwave ovens, as these are designed to heat up water molecules in food, But what almost certainly happens when the crystals are placed in dry air, for example, next to a computer, is that they lose a molecule of water, changing from the heptahydrate to the hexahydrate form, MgS04.6Hp, The hexahydrate is a powder. I myself used to produce rhombohedral crystals of a similar, but green, heptahydrate for a research project. Sadly, they would only last a week or so before turning into a limecoloured pOWder,
Eric Roche Booragul, New South Wales, Australia • The absorption of microwaves
will dehydrate the crystals and hasten their decomposition to a dry powder. Although the amount
www.last-word.com
of ambient radiation around properly functioning microwave ovens and TV sets should be quite limited, the wavelengths they employ would be easily absorbed by magnesium sulphate, and this explains the rapid decomposition that your questioner observed, Having said that, factors such as variations in humidity and air temperature cannot be excluded, nor can the fact that magnesium sulphate absorbs high-frequency sound waves -with the same result as if microwaves had been absorbed, The latter point is particularly relevant if the sample is placed by the TV, Your questioner and others might care to repeat this experiment, but with the Epsom salts sealed in airtight plastic sandwich boxes, padded with cotton wool to muffle the sound, and with a control sample placed well away from any potential source of microwave or highfrequency transmissions, to see whether a different result ensues,
Hadrian Jeffs Norwich, Norfolk, UK • Magnesium sulphate, like many
other very soluble salts, forms crystals that include a great deal of water. Some salts such as copper sulphate (CuS04,5H20) hold on to their water even in hot, dry air and remain beautifully crystalline, but others lose their water of crystallisation and crumble when humidity is low, A friend of mine in South Africa's semi-desert Karoo region saw in a shop a half-full sack of
Questions and answers should be concise,
New Scientist retains total editorial contro l
We reserve the right to edit items for clarity
over the content ofThe Last Word, Send
and style, Include a daytime telephone
questions and answers to The Last Word,
number and email address if you have one, Restrict questions to scientific enquiries about everyday phenomena. The writers of published answers will receive a cheque for £25 (or USS
equivalent), Reed Business Information Ltd reserves all rights to reuse question and answer material submitted by readers in any medium or format.
New Scientist Lacon House, B4 Theobald's
Road, London WClX BNS, UK, by emai l to
[email protected] or visit
www.last-word.com (please includ e a postal address in order to receive payment for answers), For a list of al l unanswered questions send an SAE to LWQlist at the above address,
washing soda (NazC03,lOHzO), As far as the shop assistant was concerned, it had "gone off" and "shrunk", so he let my friend take it off his hands at no cost. Had he known his chemistry, he would have realised that Karoo air can desiccate almost anything; there was nothing wrong with the soda, In warm, dry air Epsom salts also lose water of crystallisation, Microwaves should have nothing to do with this process if your oven is sound, but waste heat encourages air convection and so could speed up drying,
Jon Richfield Somerset West, South Africa
Colour of anemone For a scuba diver, one of the best underwater sights is a rock face covered in brilliantly coloured jewel anemones (Corynactis viridis), They exist in many colours, and often vivid, contrasting colours are found side by side, There a re also subdued, semi-transparent variants, Most species of wild animals have evolved to just one or a narrow range of colours, while flowers can have a range of vivid colours, presumably to attract a variety of insects, As far as I know, the anemones aren't trying to attract their prey - it just arrives on the current. So why are they so vivid and so varied? • My colleague Anya Salih and I have worked on this
question for some time in corals, which are close relatives of sea anemones. We believe that the pigments have
Do Polar Bears Get Lonely? Our latest collection serious enquiry, bri l l iant i nsight and the h ilariously unexpected Available from booksellers and at www.newscientist.com/ polarbears
a protective function against excess light, as discussed in our paper "Fluorescent pigments in corals are photoprotective", which appeared in Nature, vol 408, p 850 (DOl: 10.1038/35048564) , Unpigmented as well as pigmented versions exist in both corals and anemones, The explanation for this is probably that the production of pigments is "costly", and pigmented versions cope by being fitter than their unpigmented cousins, When conditions are unfavourable the coloured ones do better, though favourable and poor conditions are both common enough that neither form takes over. Some controversy over this interpretation remains, although we are still waiting for someone to come up with something better.
Guy Cox Electron Microscope Unit University ofSydney New South Wales, Australia
This week's question THOSE GARLIC BLUES
I made a salad dressing with olive
oil, apple cider vinegar, garlic cloves chopped into halves, fresh ginger, mixed herbs and mustard powder. When the dressing was finished I put a lidded jar of it in the fridge, and two days later topped it up again with fresh ingredients, The following day the garlic from the original batch had turned bright blue, Why?
Ellice Bourke Katherine, Northern Territory, Australia
The new Passat Highline Plus with leather as standard. From only £21,345rrp. Beautifully crafted with 'Vienna' leather upholstery, heated front seats and 17-inch 'Macau' alloys. The Passat Highline P lus now also includes a touchscreen sat-nav, Bluetooth technology and cruise control as standard allowing you to do business at your leisure. Available at typical 0% APR.' For more information call 0800 333 666 or visit www.volkswagen.co.uk
'The Pass at also includes free ser vicin g over 3 years' or 30,000 miles (whichever comes soonest). Typical 0% APR available over 3 years: including minimum deposit of 40%. Retail
may be
varied or withdrawn at any time and are not available in conjunction with the Government Scrappage Scheme. Volkswagen Finance, Freepost VWFS.
70.6 (4.0); combined 38.2 (7.4)
-
Official fuel
60.1 (4.7). CO2 emissions 124 -l72g/km. Model shown is a Passat Highline Plus 2.0 TDI
'Das Auto.
sales o nly. Vehicles orders must be placed by June 30t h, 2010. Subject to status and available to over 185 in the UK and Northern Ireland only. Indemnities may be required. These offers
consumption for the Passat Highline Plus range in mpg (litres/lOOkm): urban 28.5 (9.9) - 47.1 (6.0); extra urban 47.9 (5.9)110 PS 5-speed manual at £21,775 rrp including optional metallic paint at £430 rrp.
The last thing you want to be when you retire, is retiring. Zurich HelpPoint® is here when you need more than just i nsura n ce. We have a wide range of i nvestment and pension plans to help make you r retirement plans a reality, whether that i nvolves putting you r feet up or p utti ng you r fli ppers on. For more i nformation spea k to your Financial Adviser or visit www.zurich.co.uk/pe nsion
Here to help your world .
Because change happenz
Zurich Assurance Ltd . Reg istered in England and Wales under company number 0245667 1 . Registered Office: U K Life Centre, Station Roa d , Swi ndon, S N 1 1 EL.
®
