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WEEKLY October 24-30, 2009

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SPACE STORM ALERT 90 seconds from [atastrophe

BODY ILLUSiONS Howtofeellfke somebodv,else

HAWKING AT HOME Life, the cosmos and dressing as an alien

1st

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with your mind

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11"11UI�liI' I'.�I"


CONTENTS

Volume 204 No 2731

NEWS 5

6

Is it time to eat the dog? UPFRONT H igh stakes for NASA rocket. Ida bone hopes crushed

8

THIS WEEK

COVER STORY

EDITORIAL

The time machine in your head

Cracks emerging in Ei nstei n's theory of gravity, Human tissue built on a stack of paper, Microbes revive old coal deposits, Bird brain transplant. Women are sti ll evolving, How much of our DNA do we need? Black hole for light created on Earth 16 IN BRIEF Rain showers on the sun, Your b u l lying boss is an idiot

How your brain slices up time­ and what happens when it goes wrong

21 TECHNOLOGY

Robot hones its autopsy skills, A laser microscope to hunt for alien life, Sea anemones promise pain-free injections

Cover image

Christos Magganas

OPINION

Sunshine superpower

26 Bee truthful

It's a myth that Einstein gave us four years to live if bees died out - but don't relax just yet, say Marcelo Aizen and Lawrence Harder 27 One minute with Jeft Greason, a top gun in the space industry and fa n of crewed missions 28 LETTERS Population puzzle, Waggle dancing 30 Special measures With conventional economics in a mess, we need radical new ways to assess economic activity, says Mike Holderness

FEATURES

32 The time machine in your head

Is it really such a great idea to build a giant electricity plant in the Sahara?

(see right)

38 Sunshine superpower (see right) 42 Justice you can count on

The courts' poor grasp of mathematics risks landing more innocent people in jail 46 How green i s your pet? Rover and Fluffy can make a bigger dent in the planet's resources than a gas-guzzling SUV

Coming next week

REGULARS 28 ENIGMA

Sea monsters

48 BOOKS & ARTS

What will it mean to be able to reca l l every little fact, ask two critiques of coming data-storage technologies, La nguages on the bri n k 56 FEEDBACK W h e n dinosa urs ruled", or how to make up Earth's history to suit yourself 57 THE LAST WORD Air spray and other wonders 50 JOBS AND CAREERS

Forget dinosaurs, these are the real deal The future of woman Evolution is alive and well in

PLUS D i scove r yo u r RQ

humans - making women shorter, plumper and more fertile

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24 October 20091 NewScientist 13


New Scientist video - the list keeps getting longer.

Search from hundreds of the most amazing, mind blowing and coolest videos . Take your seat and prepare to be amazed! So what are you waiting for? Watch exclusive videos today.

www.NewScientist.com/video

NewScientist


EDITORIAL

Cute, fluffy and horribly greedy If yo u rea l ly wa nt to m a ke a sacrifice to susta i n a b i l itYt conside r ditc h i n g yo u r pet

Most consumers have come to accept the scale of the ecological crisis facing humanity. We grudgingly put out the recycling and use low-energy light bulbs. Giving up our pets in the name of sustainability may seem like a sacrifice too far, but if we are going to continue to keep animals purely for our enjoyment then we have to face uncomfortable choices. The authors' suggestion - that we should recycle our pets by eating them or turning them into pet food at the end of their lives ­ is surely a non-starter. The prospect of keeping chickens instead of dogs and cats is also unlikely to appeal.

HOW much is that doggy in the window? Waggly tail or not, owning a pet comes at a far higher cost than you might imagine. As you watch a large dog bounding out of the back of an SUV, you might mentally reprimand the owner for their choice of vehicle. You would "In a world of scarce resou rces, do better to save your indignation for their can we justify keeping pets that choice of pet. Because, as we report on page 46, consume more than some people?" the ecological footprint of our companion But there are more acceptable ways to animals can dwarf that of even the most gas­ reduce your pet's impact. Feeding the cat or guzzling cars. Man's best friend, it turns out, dog leftovers will have an immediate effect is the planet's enemy. According to the authors of the new book and also help do something about the scandal of food waste. Consumer power could also Time to Eat the Dog, it takes 0.84 hectares of land to keep a medium-sized dog fed. In be brought to bear. A trip to any supermarket contrast, running a 4.6-litre Toyota Land Cruiser, will tell you that there is a large and growing including the energy required to construct demand for " green" products, whether less­ the thing and drive it 10,000 kilometres a polluting washing powder or locally sourced food. There's no reason why the pet-food year, requires 0.41 hectares. Dogs are not the only environmental sinners. The eco-footprint industry shouldn't get in on the act. of a cat equates to that of a Volkswagen Golf. At the moment, pet-food manufacturers thrive by selling us the idea that only the If that's troubling, there is an even more shocking comparison. In 2004, the average best will do for our beloved animals, but once citizen of Vietnam had an ecological footprint owners become more aware, what they demand of 0.76 hectares. For an Ethiopian, it was from the industry is likely to change. The first manufacturer to offer a green, eco-friendly just 0.67 hectares. In a world where scarce resources are already hogged by the rich, pet food could be onto a winner. Sustainable can we really justify keeping pets that take lifestyles require sacrifices, and even cats more than some people? and dogs can be made to do their bit. _

It's hubris to say we've outgrown evolution MODERN medicine is sometimes said to have freed humans from the constraints of evolution because vaccines, drugs and surgery allow weaker genes and individuals to survive and reproduce instead of being culled by natural selection. This is a long-standing concern with important social implications : similar worries about the survival of the unfittest helped usher in the eugenics movement in the early 20th century. So it is good to see yet more evidence that we are still evolving (see page 14). In fact, researchers have made the first scientific prediction of what humanity - or at least half of it - will look like in 400 years : women will become stouter, healthier and fertile for longer. This is evolution at work. Darwin is still in charge. _

I, Robopathologist FROM Isaac Asimov's "three laws of robotics" to RoboCop, science fiction has repeatedly warned us of the dangers of handing robots autonomy. That is why surgical robots have never been more than large, complex instruments wielded by human hands: an autonomous robot with a scalpel is too much of a risk. But replace that scalpel with a scanner, and the patient with a corpse, and medical robots can finally break free (see page 22). Until one goes on the rampage around the pathology lab, of course . . _ .

What's hot on NewScientist.com g

ENVIRONMENT California's

The first survey of trash off the coast of California has found a seascape awash with fishing detritus, kitchen sinks and artillery debris. Much of it is colon ised by marine l ife, as our video revea ls

undersea landfill

ARCHIVESWhat should museums throw out? What

are the least i m portant objects from an archive including NASA photos, a 19th-centu ry surgical mask and a hippo sku ll? View our gallery to decide

SPACE Elusive lunar plume caught

NEUROSCIENCE Inside the brains

A spacecraft tra i l i n g behind NASA's LCROSS moon im pactor did manage to snap photos of a faint plume of ej ected materi a l . Resea rchers are searching the data for signs of water

of the big cats

on camera after all

• GALLERY Prize-winning Look at our gallery of pics from the Wellcome Image Awards for a new perspective on human bones and to discover how even aspirin crystals can be beautiful medical imagery

The social brain hypothesis predicts that increased bra i n size is related to increased social complexity, and i t h a s been borne out by studies in primates, Now for the first time it is tested in nine species of big cats, including lions and tigers TECH Necklace camera to capture

It takes a picture every 30 seconds, or when someone steps near or you enter a new envi ronment. Originally developed

your life

to help people with memory problems, itwill also be marketed to general consumers who don't want to forget a single thing

SPACE FLIGHTWhere should NASA send astronauts next?

New Scientist adds up "scores" for

the five options NASA could pursue in human space flight. The winner? Deep space, here we come For video, comment and online debate, visit www,newscientist.com

24 Octo ber 20091 NewScientist 15


UPFRONT

Crunch time for Ares I TALK about pressure. As the troubled

The stakes are high. A Wh ite

powers up for its fi rst flight test. a

House panel has been considering

Wh ite House panel is weighing up

cance l l ing Ares I in favou r of a

whether to cancel the project. The Ares I rocket is designed to carry a crew capsule called Orion to

EGG freezing looks increasingly promising as an insurance policy for women who need or want to delay having children, according to the first systematic monitoring of success rates for IVF using eggs that were frozen then thawed out. The results come from the first year of the Human Oocyte Preservation Experience (HOPE) Registry, which is analysing the results of thawed-egg IVF over five years. "This is the first registry to collect results in a standardised way, rather than sporadic reports of single cases," says Zsolt Peter Nagy of Reproductive Biology Associates in Atlanta, Georgia. Of the 115 IVF cycles recorded in

"About 90 per cent of the thawed human eggs had survived the IVF freezing process" the registry, about 90 per cent of thawed eggs survived the freezing process. With the most successful version of the technique - where eggs are frozen very rapidly 65 per -

6 1 N ewScientist 1 24 October 2009

Mark Lewis, former ch ief scientist for the US air force and president足

the International Space Station or

elect of the American Institute of

form part of a mission to the moon.

Aeronautics and Astronautics,

But it has been plagued with budget

recognises that policy-makers will be

problems and technical hitches.

watching the outcome close ly, but

On 27 October - or a few days later,

cent of women became pregnant. This pregnancy rate is similar to that achieved when IVF eggs have not been frozen. Nagy admits, however, that "careful selection" of the patients and egg donors may have boosted the success rate. None of the eggs was frozen for more than two years and most came from young women. Nagy presented the results at the American Society for Reproductive Medicine meeting in Atlanta. The ASRM says its advice remains that healthy women should not rely on egg freezing to preserve their fertility.

commercial launcher. Its final report is expected this week.

Earth orbit, where it could dock with

depending on how the preparations

Frozen hopes

test its flig ht-control software.

successor to NASA's space sh uttle

warns against overreacting to any technical problems that emerge

go - NASA is expected to launch the

during the test. "If they have any sort

first Ares I test flight. A solid-fuel

of g l itch and someone says, 'Oh, we

rocket l i ke those used on the space

have to cancel the prog ramme now:

shuttle will boost a dummy second

they've completely missed the point;'

stage and crew capsule to an altitude

he says. "There are always things you

of about 45 kilometres. The flight will

learn in flight that you missed or you

determine the rocket's stabil ity and

didn't properly simu late."

material into the sunlight. This fits with previous experiments WAS NASA's moon smash ill足 hinting that the debris would be ejected in a sideways spray rather conceived? Weeks before the than a vertical fountain. LCROSS spacecraft smashed into the moon on 9 October, some Even if LCROSS does turn out team members were predicting to have detected water, it will not indicate how much of it there is disappointment. Meanwhile, some critics outside NASA believe on the surface. "That tells me the fundamental rationale behind the the mission will never deliver a useful scientific result. mission was flawed," says Paul It was hoped LCROSS would kick Spudis of the Lunar and Planetary up a visible plume of debris that Institute in Houston, Texas. A could be studied for traces of lunar rover would have provided water, but a faint image detected better science, he adds. "Instead, NASA came up with a PR stunt, last week showed that the impact had thrown unexpectedly little and it kind of backfired."

Lunar washout

Beware dirty does SWINE flu and hospital superbugs may have a common weapon: the dirty hands of doctors and nurses that act as germ "superspreaders". Didier Guillemot of the Pasteur Institute in Paris, France, and colleagues created a mathematical model of a hypothetical intensive care unit (ICU) with a staff of 22. They found that staff who saw all patients briefly were better at spreading germs than those who tended a few patients very closely.


For daily news stories, visit www.NewScientist.com/news

60 SECONDS

If just one of the former always in Paris, France. These new H IV vaccine check failed to wash their hands, it analyses included people that caused more infections than if the FURTHER analysis of the first had previously been excluded from the research results, such HIV vaccine to be called a success entire staff forgot one-quarter of confirms that it had an effect, but as people who did not take the the time (Proceedings ojthe underscores it was very modest. six vaccine shots in the correct National Academy ojSciences, In September, researchers from order. In neither of these DOl : 1O.1073/pnas.0900974106). Hospitals use the consumption the US Military HIV Research Program reported that its vaccine "The analyses show that of hand-hygiene products to reduced HIV infection by 31 per monitor hand-washing, says the HIV vaccine had some team member Laura Temime of cent. Though statistically effect, but the trend is not statistically significant" the National Conservatory of Arts significant, the result was based and Trades in Paris. "Our study on very few cases, prompting suggests individual surveillance sceptics to question if the vaccine additional analyses was the trend of hand hygiene would be better." offered any protection at all. statistically significant. If the flu pandemic overwhelms Now the researchers have Other HIV researchers say these ICUs, staffwill tend more patients, presented two, more detailed analyses show the trial's success analyses of the trial at a conference was slight, but positive overall. creating more superspreaders.

Reefs' riches Coral reefs are worth $172 billion per year to the world economy. They attract tourists, act as sanctuaries for commercial fish species and protect coasts from storm surges. Pavan Sukhdev of the United Nations Environment Programme presented this as an argument for saving coral reefs from climate change at the Diversitas biodiversity conference in Cape Town, South Africa, last week.

Newton's heir Issac Newton has held it, and so has Stephen Hawking. Nowthe Lucasian Chair of Mathematics at the University of Cambridge is set to pass to Michael Green. He helped

Green deadline

Missing-link claims under fire

GREEN technologies can prevent catastrophic climate change, but only if we commit to them by 2014. Miss the deadline and we risk runaway global warming and economic meltdown. That's the conclusion of a report published this week by the environment group WWF, which says green technologies will have to grow by 22 per cent each year for the next four decades. Such growth would be the "fastest industrial revolution witnessed in our history," says Kim Carstensen of WWF. The result would be a 63 per cent drop in emissions of key greenhouse gases between 1990 and 2050 - enough to prevent global warming exceeding the 2 째C limit agreed by the G8 industrial nations. The report, written by Karl Mallon and colleagues at the Australian insurance industry consultant Climate Risk, warns that only three green energy technologies out of 20 assessed are growing fast enough: wind, solar photovoltaics and biodiesel. The reindustrialisation will cost $17 trillion worldwide by 2050, of which $7 trillion will go towards renewable energy technologies and the rest towards energy efficiency, low-carbon agriculture and sustainable forestry.

APPEARANCES can be deceptive.

trigger the "first superstring revolution", which showed string

contradicted now by Erik Seiffert at

theory can describe elementary particles and their interactions.

Despite claims that it may be a

Stony Brook University, New York. His

missing link between primate groups,

team recently found a 37-million-year-

a beautifully complete fossil that

old primate jawbone fossil in Egypt

Alien worlds galore

made headlines in May might

from a new genus named A/radapis.

A haul of 32 new extrasolar bodies

nevertheless be too damaged to

Their study claims that both Afradapis

has bumped up the number of

reveal much about primate evolution.

and Darwiniussit firmly on the lemur

known exoplanets to more than

When Ida, the only known fossil of

branch of the evolutionary tree

400. The discoveries were made

(Nature, 001: 10.1038/nature08429).

by HARPS, an instrument that

unveiled, many were impressed by its

Seiffert reckons Ida is too poorly

analyses wobbles in starlight

exquisite preservation. Jarn Hurum at

preserved to clarify primate evolution.

caused by distant planets. The find

the University of Oslo, Norway, and

"When it comes to the key features

increases by one-third the number

the Darwinius masillae species, was

colleagues analysed the fossil and

that primate palaeontologists so

of known low-mass planets -those

suggested it shared characteristics

often depend on, Darwiniusis

up to roughly twice Earth's mass.

with both major groups of existing

surprisingly uninformative," he says:

primates -lemurs and lorises, and

the skull is crushed and the ankle

apes and monkeys -and so helped

damaged. He based this judgement

to link them.

on photos and a cast of Ida, which

That conclusion was hotly contested at the time, and is

Hurum says is insufficient to make such "harsh" statements.

Layoff medical users Federal prosecutors should not investigate people who take marijuana for medical reasons -nor their legitimate suppliers -in the 14 US states that allow the medicinal use of cannabis. So says guidance from the US Department of Justice to clarify how to deal with users in these states.

'Qctodoc' expelled The American Society for Reproductive Medicine has expelled Michael Kamrava of Beverly Hills, California, the fertility doctor who gave Nadya Suleman IVF treatment that led to the birth of octuplets. This won't stop him practising medicine but should send a strong message to his future patients.

24 October 2009 1 N ewScientist 1 7


THIS WEEK

Rachel Courtland

EVER since Arthur Eddington travelled to the island of Prfncipe offAfrica to measure starlight bending around the sun during a 1919 eclipse, evidence for Einstein's theory of general relativity has only become stronger. Could it now be that starlight from distant galaxies is illuminating cracks in the theory's foundation? Everything from the concept 8 1 NewScientist 1 24 Octo ber 2009

of the black hole to GPS timing owes a debt to the theory of general relativity, which describes how gravity arises from the geometry of space and time. The sun's gravitational field, for instance, bends starlight passing nearby because its mass is warping the surrounding space-time. This theory has held up to precision tests in the solar system and beyond, and has explained everything from the

odd orbit of Mercury to the way pairs of neutron stars perform their pas de deux. Yet it is still not clear how well general relativity holds up over cosmic scales, at distances much larger than the span of single galaxies. Now the first, tentative hint of a deviation from general relativity has been found. While the evidence is far from watertight, if confirmed by bigger surveys, it may indicate either that Einstein's

theory is incomplete, or else that dark energy, the stuff thought to be accelerating the expansion of the universe, is much weirder than we thought (see "Not dark energy, dark fluid". The analysis of starlight data by cosmologist Rachel Bean of Comell University in Ithaca, New York, has generated quite a stir. Shortly after the paper was published on the pre-print physics archive, prominent


In this section

• Human tissue built on paper stack, page 10 • Bird brain transplant, page 12 • Future of women, page 14

physicist Sean Carroll of the California Institute of Technology in Pasadena praised Bean's research. "This is serious work by a respected cosmologist," he wrote on his blog Cosmic Variance. "Either the result is wrong, and we should be working hard to find out why, or it's right, and we're on the cusp of a revolution." "It has caused quite a furore in astronomy circles," says Richard Massey of the Royal Observatory Edinburgh in the UK. "This paper

the visible and even unseen matter that bend their light. The weak lensing technique can also be used to measure two different effects of gravity. General relativity calls for gravity's curvature of space to be equivalent to its curvature of time. Light should be influenced in equal amounts by both. When the COSMOS data was released in 2007, the team - led by Massey - assumed these two factors were equivalent. Their analysis revealed that gravitational tugs on light were stronger than "If it is wrong, we should be anticipated, but they put this working hard to find out down to a slightly higher why, but if it's rig ht, we are concentration of ordinary and on the cusp of a revolution" dark matter in the survey's patch of sky than had been predicted. To look for potential deviations has generated a lot of interest." from general relativity, Bean Bean found her evidence reanalysed the data and dropped lurking in existing data collected the requirement that these two by the Cosmic Evolution Survey, a multi-telescope imaging project components of gravity had to be equal. Instead the ratio of the two that includes the longest survey yet by the Hubble Space Telescope. was allowed to change in value. COSMOS, which detected more She found that between 8 and than 2 million galaxies over 11 billion years ago gravity's a small patch of sky, takes distortion of time appeared to be advantage of gravity's ability to three times as strong as its ability bend light. Massive objects to curve space. An observer like galaxy clusters bend the light around at the time wouldn't have noticed the effect because it of more distant objects so that it is directed towards or away only applies over large distances. from Earth. This effect, called Nonetheless, "there is a preference gravitational lensing, is at its for a significant deviation from general relativity", says Bean most dramatic when it creates (www.arxiv.org/abs/ogo9.38S3). kaleidoscopic effects like At this stage, it's hard to say luminous rings or the appearance what would happen if the of multiple copies of a galaxy. deviation from general relativity The sky is also dominated by the distorting effects of "weak was confirmed. Cosmologists lensing", in which intervening have already considered some modifications to general relativity matter bends light to subtly alter that could explain the universe's the shapes and orientations of more distant galaxies, creating an acceleration (see "Not dark energy, effect similar to that of looking dark fluid") . Yet finding a deviation when through old window glass. Since the universe was less than half its galaxies come in all shapes and current age is odd - if general sizes, it is difficult to know whether the light from an relativity had broken down at some level, the signs should be individual galaxy has been most dramatic more recently, distorted, because there is nothing to compare it with. But by long after the repulsive effect of looking for common factors in the dark energy overwhelmed the attractive powers of gravity some distortion of many galaxies, it is possible to build up a map of both 6 billion years ago.

NOT DARK ENERGY, DARK FLUID Dark energy could be weirder than

While matter will be confined to

we thought. Evidence that over large

three dimensions, gravity could be

distances gravity exerts a greater pull

leaking into this extra dimension.

on time than on space (see main

When the universe becomes large

story) might not necessarily suggest

enough, this gravity could interact

that the theory of general relativity is

with matter in the brane, to produce

wrong. It could instead be a sign that

acceleration on large scales.

the universe's acceleration may require a more exotic explanation. The simplest way of explaining the

A deviation could also be a sign that dark energy is a more complex "fluid" that exerts varying pressures

universe's acceleration is to invoke a

in different directions. The snag is

cosmological constant. originally

that telling the difference between a

proposed by Einstein to allow the

more exotic form of dark energy and

universe to remain the same size

a modification to our understanding

in the presence of matter. This

of gravity could be tricky.

describes a universe filled with uniform, outward-pushing energy.

"If we were to detect a departure:' says cosmologist Alessandra Silvestri

But there are other possible

of the Massachusetts Institute of

explanations for acceleration.

Technology, we might not be able to

One idea is that the entire universe

tell whether there is a flaw in general

exists on a membrane, or brane,

relativity or just evidence that dark

floating inside an extra dimension.

energy is "some sort of fancy fluid".

Most astronomers, including Bean, are cautious about the results. "Nobody is yet betting money that the effect is real," says cosmologist Dragan Huterer of the University of Michigan in Ann Arbor. Various other explanations, like a bias in the technique used to estimate the distances to galaxies, now need to be ruled out. Although COSMOS photographed a deep patch of sky, it was fairly small by the

"Gravity's distortion of time appeared to be three times as strong as its ability to curve space" standards of modern surveys. This opens up the possibility that this region might be anomalous, notes Asantha Cooray, an astrophysicist at the University of California, Irvine. "You could have a massive galaxy cluster that could boost your weak lensing signal up. Or by random chance you could have more dark matter," says Cooray, part of a team that analysed other survey data taken with the Canada-

France-Hawaii Telescope in Hawaii and found no hint of a departure from general relativity. "The only way to take that into account is to look at data in a larger field." Future projects will scan the sky over much wider areas and collect images of many more lensed galaxies. For example, the Dark Energy Survey is poised to start surveying the sky from 2011 and will build up an even more precise picture of how light has been bent over the course of the universe's history. Whether these surveys find the effect or not, Bean hopes that her paper will generate more interest in the idea of using weak lensing to test general relativity. "I'm not putting my flag out there and saying this is a real thing," Bean says. "We need to look at more data sets. This is really just the first stage for trying to test gravity in this way." Massey agrees : "At the moment we're in the mode of just trying to hack into general relativity to find the chinks in its armour, to find any places where it might not be working." • 24 October 2009 1 N ewScientist 1 9


THIS WEEK

Stack 'em on paper to grow cells in 3D

Better embryo selection boosts IVFsuccess

Jessica Hamzelou

been greatly improved in women

MODERN offices may scorn the stuff, but paper has found a new use in the laboratory - as the basis for 3D models of tumours and damaged hearts. Chemist George Whitesides and his colleagues at Harvard University reckon that the balls of cells they have grown at the centre of stacked paper could help us better understand how tumours and damaged hearts respond to drugs, and even to select therapies most suited to individuals. Cells tend to be grown on flat plates in the lab, which isn't representative of the 3D structure of cells in the body. "It's nothing like human tissue," says Whitesides. In our bodies, cells are exposed to natural concentration gradients: the further away they are from major blood vessels, the less oxygen and nutrients they get. But in 2D cell cultures, such gradients aren't present. "We need to move away from those boring flatlands that cell culture dishes represent," says cell biologist Emmanuel Reynaud of University College Dublin, who was not involved in the research. Although techniques for growing cells in 3D exist, many are time-consuming and far from

seemed that the outer cells closer to the medium were nourished while the cells on the inside showed signs of being starved, which is what you would expect to happen to a tumour inside the body (Proceedings ojthe National Academy ojSciences, DOl : perfect. For example, once the cells have grown, the cultures lO.lo73pnas.oglo666106). need to be sliced with a knife to Whitesides says that such 3D be analysed. "Not only does this cultures will help probe diseases where some tissue is oxygen or kill some cells, it's extremely difficult to do," Whitesides says. nutrient deprived. This would include cases where heart tissue His group has now developed a becomes damaged after being cheap alternative. The team start by squirting deprived temporarily of oxygen a gel containing their cells due to a blockage in the blood supply. "We don't know if tissue onto small sheets of sterile chromatography paper. The cells dies because of a lack of oxygen or they used included human lung when oxygen levels are restored," says Whitesides. cancer cells, human fibroblasts, which make up connective tissue, Cultures grown on paper could also be used to test drugs to treat and mouse immune cells. "I tried everything I could get my hands these conditions, which could be on," says Whitesides. personalised. "We could take cells from a patient, grow them and see "The balls of cells built how they'd respond to different drugs," he says. The group also on paper could help us points out that paper has the understand how tumours advantage of being widely respond to drugs" available, abundant and cheap. The cells seeped through the Kenneth Yamada, chief cell paper "like coffee through a biologist at the National Institutes napkin", he says. When the of Health in Bethesda, Maryland, researchers stacked up eight calls the approach "clever" and "innovative". But since sheets of cell-infused paper and suspended them in an oxygen and Whitesides's team only grew the cells for nine days, he questions if nutrient-rich broth, they found that the cells grew into a ball (see the layers would be as easy to pull apart "after they have formed diagram, below). To analyse how these cells organised tissues". Reynaud, behaved, the researchers simply however, is convinced by the peeled off the layers one at a time technique : "I will happily peel and analysed them individually. It from now on." •

PREGNANCY and birth rates have undergoing IVF by changing the -

way embryos are selected. Before transfer to the uterus, embryos can be screened to rule out any with chromosome abnormalities, which can cause miscarriage and implantation failure, as well as conditions such as Down's syndrome. However, the techniques used at present either only reveal abnormalities on some chromosomes or require cells to be taken from small, 3-day-old embryos, raising concerns that the embryos could be damaged. "You're taking quite a significant proportion of its mass," says Dagan Wells at the University of Oxford. To dodge these problems, Wells and his colleagues used a technique called comparative genome hybridisation (CGH), which makes it possible to study all of the chromosomes in a cell taken from a 5-day-old embryo, which has several hundred cells. They have used CGH in 42 women undergoing IVF. On 21 October at the annual meeting of the American Society for Reproductive Medicine in Atlanta, Georgia, Wells reported that 36 of these women have become pregnant, of whom 15 have so far given birth. His team measured an implantation rate of 66 per cent of all CGH embryos transferred, compared with 28 per cent of unscreened embryos, and, taking into account the stage of pregnancy, a birth rate

of 80 per cent compared with 60 per

Paper a-peel

cent in unscreened embryos.

How to cultivate and test cells in 3D on stacks of paper

"The figures are quite amazing," says Stuart Lavery of the Wolfson Family Clinic at Hammersmith Hospital in London. However, he points out that the pregnancy rate among the women in the trial who received embryos that hadn't undergone CGH, although lower than the group whose embryos had, was To ana lyse, peel off the layers

Squirt cells suspended i n gel onto

Pl ace stack i n nutrient and oxyg e n -rich broth.

circles of paper. When cells soak

Cells bond together and form a ball rath e r l i ke

and look at ind ividual sheets

throug h, stack more sheets o n top

3D tissue in the body. Add drugs for test i n g

under a microscope

10 1 NewSci entist 1 24 Octo ber 2009

still higher than average, so more data is needed to confirm the reported success rates. Linda Geddes •


For daily news stories, visit www.NewScientist.com/news

Subterranean microbes revive tired old gas fields WHATEVER you may think of our addiction to fossil fuels, there is no shortage of ideas on how to extract every last tonne. Field trials are now showing that all it takes is common fertiliser. Natural gas is often present in coalfields, clinging to the coal. It is extracted through wells drilled into the coal seam, but once production tails off the industry usually moves on. That's when biogenic methane companies propose to move in. By pumping water and nutrients back down the wells to feed microbes living in the coal they expect to be able to kick-start the microbes' methane-producing metabolism. More gas can then be harvested. The US Geological Survey and CSIRO, the Australian national science agency, have been exploring the idea for a number of years. "We have shown that this process works on coal in the lab, and I think that it will be possible to make it work on an industrial scale," says Phil Hendry at CSIRO in North Ryde, New South Wales. The Canadian company Profero Energy intends to test biogenic methane

gas from 100 leased wells in Wyoming to heat 16,000 homes for a year. Finkelstein will not give details of the nutrients his company uses to fertilise the subterranean organisms, but says you could buy most of them "off the shelf". The results of the 2007 experiment were compelling: "We made 1 billion cubic feet [30 million cubic metres 1 of methane," Finkelstein says. That's above and beyond what would have been made without the nutrients. Money from the sale of the extra gas was split between Luca and the wells' owner, who Finkelstein says does not wish to be named. "Most of Luca's expenses in 2008 and part of 2009 were covered by gas sales," he says. The company now owns and "farms" some 630 wells in the US that the traditional industry classifies as marginal. By the end of this year that number will have risen to 1000, Finkelstein says. He points out that utility companies are considering converting from coal to methane to cut down on their carbon footprint. "Luca's technology can help make this transformation "Water and nutrients more reliable and economic," he pumped into the wells kick­ says. He is also keen to point out starts microbes' methane­ that Luca makes use of existing infrastructure. "The wells have prod ucing metabolism" been drilled and the roads, pipes technology in Canadian tar sands and compressors to capture gas are already there." (New Scientist, 18 April, p 8). "Given the demand for fossil Although biogenic methane produced this way has been on fuels, it seems to me inevitable the agenda for several years, it's that such 'exotic' forms of fossil unclear which methods will carbon will be developed and work best, says Elizabeth Jones, exploited," says Myles Allen, head of the Climate Dynamics group a microbiologist at the US Geological Survey. at the University of Oxford. "This all points to the need to neutralise Mark Finkelstein, president of their impact on climate by Luca Technologies, a firm based in Golden, Colorado, begs to differ. developing and implementing technologies for carbon capture In field experiments in 2007, his company generated enough and sequestration." Colin Barras •

Surviving pandemics: a pathogen's perspective Rosalind Franklin Prize Lecture Monday 2 November at 6.30pm Professor Sunetra Gupta U n iversity of Oxford

One of the biggest challenges faced by pathogens in their bid for survival is the host immune response. Within an infected individual. pathogen populations face direct attack by the different processes of the immune system; at a community level. immunity affects pathogen fitness by reducing the pool of susceptible persons. Professor Gupta will discuss how pathogens have evolved under this form of natural selection and found solutions that allow them to persist within individuals and within communities using examples from malaria. bacterial meningitis and influenza. Sunetra Gupta is Professor of Theoretical Epidemiology at the University of Oxford.

1350

twenty ten years of and beyond excellence in science

24 October 20091 N ewScientist 111


THIS WEEK INSIGHT Pregnancy dilemma: antidepressants and depression may both harm a f etus A US j u ry's decision that an a ntidepressant caused heart defects in an unborn baby is highl ighting the painful d i lemma facing pregnant women with depression, The most common antidepressants have been l inked to birth defects and miscarriage, yet some doctors fear that letting depressive symptoms go untreated may have long-term consequences for the mother and her unborn baby. On 15 October, a jury i n Philadelphia, Pennsylvania, ordered manufacturer G laxoSmithKline to pay $2.5 m i l l ion to the family of 3-year-old Lyam Kilker, who was born with serious heart defects, While pregnant, Kilker's mother took the antidepressant paroxetine (Seroxat or Paxil), which belongs to the most commonly prescri bed class of a ntidepressants, known as selective serotonin reuptake inhibitors (SSRls), Doctors try to avoid giving d rugs to pregnant women, but Ki lker's mother is not unusual. Antidepressants a re i ncreasi ngly being prescribed during pregnancy, particularly i n the US, where 13 per cent of pregnant women took them in 2003, The trend reflects an increase in

Secret of song lies in birds with 'two' brains

Taking antidepressants while pregnant is increasingly common

while pregnant took longer to sta rt smil ing, talking and developing motor skills (BJOC, vo1 115, P 1043), At the same time, evidence is growing that SSRls may harm fetuses, While some studies have found SSRls have no effect, others find that they increase the chance of fetal heart defects and of miscarriage, The most recent study found an increased preva lence of septa l heart defects, also known as a hole in the heart, among children whose mothers were prescri bed an SS RI in early pregnancy (BM), vo1 339, p b3569), This was pronounced for two SSRls, though no

association was found with paroxetine, Pa roxetine's label warns that it may raise the risk of birth defects, but in the case of Lyam Kilker, GSK denies its drug was responsi ble and says it will appeal the ru ling: 'The scientific evidence does not establish that exposure to [paroxetinej during preg nancy caused his condition," To help doctors and patients weigh up the risks and benefits, in August the American College of Obstetricians and Gynecologists and the American Psychiatric Association released a review of studies examining the effects of taking antidepressants and of being depressed during pregnancy. They concluded that women who get pregnant while on antidepressants should consider switching to psychotherapy, especially in mild cases, They also recommend that doctors discuss the risks and benefits of taking SSRls with women who become depressed d u ring pregnancy, David Healy, a psychiatrist atthe North West Wales NHS Trust in Bangor, U K, who gave evidence for the Kilke r fa m i ly, told New Scientist that all women of childbearing age, preg nant or not, should be warned about the risks before sta rting an SSRI, as com ing off the drugs can be very hard due to withdrawa l sym ptoms, Clare Wilson •

I started this project that it was

of a pen tip. jarvis announced his

so far all the chimeric birds have

one of those crazy ones."

first results at the Society for

died just before hatching.

their use i n the genera l population: often a woman is already taking antidepressa nts when she becomes pregnant Awa reness is a lso g rowi ng of the potential risks of not treating depression d u ring pregnancy, on the child as wel l as the mother. Last year, a large study showed that childre n whose mothers h a d b e e n depressed

Both people and songbirds learn how to communicate in infancy by

Neuroscience's annual meeting in Chicago last week. The team has

That's probably because the two species develop too differently,

listening to adults and imitating their

removed the tissue from a quail

jarvis says. Quail chicks are more

sounds. In the embryo, neurons from

embryo that gives rise to the

mature when they hatch compared

CREATING chimeras with the higher

learning centres in the higher brain,

forebrain and replaced it with the

with finch chicks, which are relatively

brain of a songbird and the hindbrain

or fore brain, connect up with neurons

same tissue from a finch embryo.

helpless. The team are considering

of a non-singer may one day shed

in the hindbrain that control vocal

They found that some of the finch

switching quails for a species that

light on the evolution of birdsong,

muscles in the throat. These

neurons make a beeline for the

develops at a similar pace to finches.

and even human speech.

connections are absent in non­

quail's hindbrain.

"The goal is to get a non-singing

singing birds such as quails, which

The team do not yet know if the

Other researchers have used partial brain transplants between

animal that can actually learn

simply squawk. A quail's call is innate

neurons can successfully connect

quails and chickens to show that

how to imitate sounds," says Erich

and is not learned from a parent.

with the hindbrain, however, and

the midbrain directs the innate

jarvis, a neuroscientist at Duke University in Durham, North Carolina.

jarvis's team is investigating how forebrain neurons are normally

The chimera would have the

guided to the hindbrain in a songbird

hindbrain of a quail and the forebrain

by doing brain transplants on bird

of the zebra finch. "I knew when 12 1 NewScientist 1 24 October 2009

embryos that are 2 days old -the size

squawking or crowing in non-singing

"This is the first time that transplants have been used to investigate song learning in songbirds"

birds. This is the first time, however, that transplants have been used to investigate song learning in songbirds. Ewen Ca llaway •


Conversations for a Smarter Planet.

,

I ,

Smarter energy for a smarter planet. For most o f the last centu ry, o u r electrical g r i d s were a sym b o l of

b u s i nesses on h o w t h e y c a n c o n s u m e m o re efficiently. Decisions

progress. The inexpens ive, abundant power they brought changed

by u t i l ity companies on how they can better m a n a g e d e l ivery

the way t h e world worked - f i l l i n g h o m e s , streets, b u s i n e s s e s ,

and balance load s . D e c i s i o n s by g ove r n m e nts and societies on

t o w n s a n d c i t i e s with e n e rgy.

how to prese rve o u r environment. The whole system can become

But today's e l ectrical grids reflect a time when energy was cheap,

m o re effi c i e n t , re l i a b l e , adaptive . . . smart.

t h e i r i m p act o n the natural e n v i r o n m e n t was n't a p ri o rity and

Smart grid projects are a l ready helping consumers save 1 0% on

c o n s u m e rs weren't even part of the e q u at i o n . Back then, the

their b i l l s and are red u c i n g peak demand by 15%. I m agine the

powe r syste m

could

be c e ntra l i s e d , c l o s e l y managed

and

p ote n t i a l sav i n g s w h e n t h i s i s s c a l e d to i n c l u d e e n t e r p r i s e ,

s u p p l i e d by a relative l y s m a l l n u m b e r of large power p l ants .

g ove r n m e n t d e p a r t m e nts a n d u n i v e r s i t i e s . A n d i m a g i n e t h e

It was d e s i g n e d to d i stri b ute power in o n e d i rection o n l y - not

e c o n o m i c st i m u l u s that an i n vest m e n t i n s m a rter g r i d s c o u l d

to manage a d y n a m i c g l obal network of e n e rgy s u p p l y and

prov i d e i n o u r cu rrent c r i s i s .

demand.

I n fact , t h e re's no n e e d f o r m e re i m a g i nati o n . A recent report

As a res u l t o f i n efficiencies i n this syste m , the wor l d ' s creation a n d

by the London School of Economics calcu lates that an i nvestm ent

d i st r i b u t i o n of e l ectric p o w e r i s now wastefu l . W i t h l ittle o r no

of ÂŁ5 b i l l i o n i n t h e d eve l o p m ent of a smart power grid i n the

inte l l i g e n c e to b a l a n c e loads o r m o n itor power flows, e n o u g h

UK

e l ectricity i s lost a n n u a l l y t o power I n d i a , Germany and Canada

e n e rgy and related i n d ustries. I t c o u l d e n a b l e new forms of

for an e n t i re year. I n the

UK,

Gove r n m e n t p roject i o n s s h ow t h at

w i t h o u t new capacity g e n e rati o n , s u p p l y w i l l not meet d e m a n d by 20 1 6, w h i l st a t the same t i m e b i l l i o n s o f p o u n d s a r e wasted on e n e rgy that never reac hes a single l i g ht b u l b .

c o u l d create o r retain a l most a q u arter of a m i l l i o n jobs in

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g l o b a l l y t o acce l e rate the adoption o f smart g r i d s t o h e l p make

l i ke the c o m p l ex global system it i s .

them more re l i a b l e and give c u stomers better usage i n formati o n .

W e c a n now i n strument everyth i n g from t h e meter i n t h e h o m e to

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THIS WEEK

Evolution is alive and well in modern women WOMEN of the future are likely to be slightly shorter and plumper, have healthier hearts and longer reproductive windows. These changes are predicted by the strongest proof to date that humans are still evolving. Medical advances mean that many people who once would have died young now live to a ripe old age. This has led to a belief that natural selection no longer affects humans and, therefore, that we have stopped evolving. "That's just plain false," says Stephen Steams, an evolutionary biologist at Yale University. He says that although differences in survival may no longer select "fitter" humans and their genes, differences in reproduction still can. The question is whether women who have more children have distinguishing traits which they pass on to their offspring. To find out, Steams and his colleagues turned to data from the Framingham Heart Study, which has tracked the medical histories of more than 14,000 residents of the town of Framingham, Massachusetts, since 1948 - spanning three generations in some families. The team studied 2238 women

How much of our DNA do we need anyway?

who had passed menopause and so completed their reproductive lives. For this group, Steams's team tested whether a woman's height, weight, blood pressure, cholesterol or other traits correlated with the number of children she had borne. They controlled for changes due to social and cultural factors to calculate how strongly natural selection is shaping these traits. Quite a lot, it turns out. Shorter, heavier women tended to have more children, on average, than taller, lighter ones. Women with lower blood pressure and lower cholesterol levels likewise reared more children, and - not surprisingly - so did women who had their first child at a younger age or who entered menopause later. Strikingly, these traits were passed on to their daughters, who in turn also had more children. If these trends continue for 10 generations, Steams calculates, the average woman in 2409 will be 2 centimetres shorter and 1 kilogram heavier than she is today. She will bear her first child about 5 months earlier and enter menopause 10 months later (Proceedings ojthe National Academy ojSciences, DOl:

D

10.1073/pnas.0906199106). conclusion from geographic It's hard to say what is selecting differences in gene frequencies, for these traits, and to discern rather than from direct measurements of reproductive whether they are being passed down through the women's genes. success. That leaves Steams's But because Steams controlled study as perhaps the most detailed measure of evolution for many social and cultural factors, it is likely that his results in humans today. "It's interesting that the document genetic, rather than underlying biological framework cultural evolution at work. is still detectable beneath the It is not the first study to conclude that natural selection culture," he says. Analyses of other is operating on humans today; long-term medical data sets could the difference is that much of the explore the interplay between earlier work has drawn that genetics and culture. Bob Holmes •

genome. "You don't need a complete

one individual, and a third in more

flagged up may once have been

genome to be a complete person:'

than 5 per cent of people in the study.

essential but aren't any more, either

says Terry Vrijenhoek of the Radboud

The deletions disrupted 39 known

because we now need different

University Nijmegen Medical Centre

genes, most of which are involved

abilities to survive, or genes have

in the Netherlands. To put a figure on how much of our

in immune defence, smell and other

evolved elsewhere in the genome

senses. Vrijenhoek will present the

to do the same job, perhaps better.

IT'S the blueprint for life, but not all of

DNA is non-essential. Vrijenhoek and

results on 24 October at the annual

Earlier this year researchers at

our genome is truly mission-critical.

his colleagues screened the genomes

meeting of the American Society of

the Sanger Institute in Cambridge,

Now the first systematic search for

of 600 healthy students, searching

Human Genetics in Honolulu, Hawaii.

non-essential regions of the human

for chunks of DNA at least 10,000

Why do we have non-essential

UK, used a scan of disrupted genes to estimate that around 1 in

genome is providing an estimate of

base pairs in length that were missing

DNA? Team leader Joris Veltman

200 genes is non-essential. Veltman

the "minimal genome" needed by a

in some individuals. Across all the

suggests that the regions his team

says his team is the first to search

healthy human being, as well as clues

genomes, about 2000 such chunks

to our evolutionary history.

were missing - amounting to about

Previous studies suggested it is possible to lead a full and healthy life without every single bit of the 14 1 NewScientist 1 24 Octo ber 2009

0.12 per cent of the total genome. Just over two-thirds of the "deletions" were found in more than

the whole human genome - not just

"About 2000 chunks of DNA, some of which disru pted genes, were found to be non-essential"

genes - for non-essential elements. He notes that which genes are non-essential may vary between ethnic groups. Andy Coghlan •


For daily news stories, visit www.NewScientist.com/news

Table-top 'black hole' made on Earth possible to build a device that makes light curve inwards towards its centre in a similar EAT your heart out, Large way. They calculated that this Hadron Collider. Long before the particle accelerator has had could be done by a cylindrical structure consisting of a central an opportunity to vindicate the doomsayers by sucking our planet core surrounded by a shell of concentric rings (Applied Physics into oblivion, a black hole has been created in a laboratory. Letters, vo1 95, p 04110 6). Happily, this one only sucks in The key to making light curve inwards is to make the shell's light, not people. permittivity - which affects the The device in question traps microwaves, and is now being electric component of an adapted to catch visible light. electromagnetic wave - increase smoothly from the outer to the It could lead to a new and more efficient way to gather sunlight inner surface. This is analogous to generate solar electricity. to the curvature of space-time A theoretical design for a table­ near a black hole. At the point top black hole to trap light was where the shell meets the core, proposed in a paper published the permittivity of the ring must earlier this year by Evgenii match that of the core, so that light is absorbed rather than reflected. Narimanov and Alexander Now Tie Jun Cui and Qiang Kildishev of Purdue University in West Lafayette, Indiana. Their Cheng at the Southeast University idea was to mimic the properties in Nanjing, China, have put of a cosmological black hole, Narimanov and Kildishev's theory whose intense gravity bends the into practice, and built a "black surrounding space-time, causing hole" for microwave frequencies (arxiv.org/abs/091O.2159v1). any nearby matter or radiation to follow the warped space-time It is made of 60 annular strips and spiral inwards. of so-called metamaterials, which Narimanov and Kildishev have previously been used to reasoned that it should be make invisibility cloaks. Anil Ananthaswamy

Sucking in light

Microwaves a re sucked i nto the core of the " black hole" by s u btly changing

the size of structures withi n concentric rings of metamaterial as they get nearer to the core

OUTER RIN GS' PROFILE

Each strip takes the form of a circuit board etched with structures whose dimensions change progressively from one strip to the next, so that the permittivity varies smoothly (see diagram) . "When the incident electromagnetic wave hits the device, the wave will be trapped and guided in the shell region towards the core of the black hole, and will then be absorbed by the

"The device could lead to a new and more efficient way to gather sunlight to generate solar electricity" core," says Cui. "The wave will not come out from the black hole." In their device, the core converts the absorbed light into heat. Narimanov is impressed by Cui and Cheng's implementation of his design. "I am surprised that they

have done it so quickly," he says. Fabricating a device that captures optical wavelengths in the same way will not be easy, as visible light has a wavelength orders of magnitude smaller than that of microwave radiation. This will require the etched structures to be correspondingly smaller too. Cui is confident that they can do it. "I expect that our demonstration of the optical black hole will be available by the end of 2009," he says. Such a device could be used to harvest solar energy in places where the light is too diffuse for mirrors to concentrate it onto a solar cell. An optical black hole would suck it all in and direct it at a solar cell sitting at the core. "If that works, you will no longer require these huge parabolic mirrors to collect light," says Narimanov. •

The Li l liput laboratory:

chem istry & biology on the sma l l sca le

Clifford Paterson Prize Lecture Thu rsday 29 October 2009 at 6.30pm Professor And rew de Mello I m p e r i a l Coll e g e London I n 1 9 59, Richard Feynman proposed a variety of new nano-tools including the concept of 'atom by atom' fabrication. In the intervening decades, many of these predictions have become reality; electronic systems have contracted to sizes close to the molecular level, scanning probe microscopes allow us to image and manipulate individual atoms, and the molecular machinery of living systems is now being more fully understood and harnessed. Professor de Mello's lecture will assess the current impact of lab-on-a-chip technology in chemistry and biology and ponder future applications in molecular diagnostics, early stage disease discovery and intelligent molecular synthesis.

1350

twenty ten years of and beyond excellence in science

24 October 2009 1 NewScientist 1 15


IN BRIEF Algae damag ing sea lions' brains

Sun's rain could explain why corona heat is insane

Now simulations seem to show that the coronal rain is a result of the process that makes the corona so hot. Two theories have previously been put forward to

ALGAL red tides can have some odd effects on marine creatures 足 causing sea lions to stray into pools and parking lots, for instance. Now high-tech medical equipment is offering a peek inside the animals' skulls to discover what causes such bizarre behaviour. Eric Montie of the University of South Florida in St Petersburg studied wild sea lions, including some that showed symptoms of poisoning by domoic acid - the neurotoxin secreted by the algae. He placed anaesthetised sea lions in an MRI scanner to image their brains, and found that the hippocampus of sick animals was half the size of that in healthy ones. The hippocampus controls an animal's spatial awareness, which could explain why poisoned sea lions often get lost. The work has been welcomed by other biologists as a key step towards using MRI to study how marine mammals communicate.

explain the anomaly. One suggests the corona is heated THE sun's million-degree outer atmosphere is the last

via small explosions called nanoflares lower in the

place you would expect to find rain, yet a form of the

atmosphere. These would push gas up into the corona,

stuff could help explain why the sun's outer atmosphere,

where it radiates away its energy. The other theory

or corona, is much hotter than you might expect.

suggests the heat energy is deposited by magnetic

(oronal rain is made of dense knots of relatively cold

Placebo effect caught in the act

waves rippling through the corona.

THE placebo effect's ability to deaden pain has been pinpointed to cells in the spinal cord. This the outer atmosphere. "There's just this constant rain of found gas heated from below by nanoflares could cool these blobs that seem to be coming down from high up," and condense higher up to make the rain, whereas the hints at new ways to treat pain. Falk Eippert of the University says Judy Karpen of NASA's Goddard Space Flight (enter magnetic waves kept the high-altitude gas too hot to Medical Centre Hamburg足 in Greenbelt, Maryland. condense (www.arxiv.org/abs/0910.2383). Eppendorf in Germany and colleagues scanned the upper spinal cords of 13 volunteers while 12 particular light -sensitive f f Fruit lies star in remake o Total Recall neurons learned to avoid the applying intense heat to the left release dopamine in the presence laser-related odour, just like arm. Then they applied a cream WHAT do fruit flies and Arnold Schwarzenegger have in normal flies exposed to electric of an odour, without actually to the arm and told the volunteers common? They have both hurting the flies, might also teach shocks (Cell, DOl : 10.1016/ it contained a painkiller. In fact appeared to have false memories. them to avoid the smell. it had no active ingredient, j.cell.2oog.o8.034) . The release of dopamine by Miesenbock concludes that but all the same it quenched His team genetically modified certain neurons is key to fruit fly fruit flies so that certain neurons stimulating these neurons creates pain-linked neural activity at learning: Gero Miesenbock at the fired when flashed by a laser; the fruit fly equivalent of a painful lower neck level in the left dorsal University of Oxford knew that different flies were given different memory. It's not clear whether the horn, which runs the length of it occurs when the flies learn to sets of light-sensitive neurons. same thing would work in humans: the spinal cord (Science, DOl : associate an electric shock with a The team then lasered the flies someone should have told 10.1126/science.1180142) . smell, for instance. He wondered Douglas Quaid, Schwarzenegger's whenever they came into contact Monitoring such activity could be a way to test novel painkillers. if stimulating the right neurons to with a certain smell. Flies that had character in the film Total Recall. gas, at tens or hundreds of thousands of degrees (,

which pours down towards the sun's visible surface from

16 1 NewScientist 1 24 Octo ber 2009

When Patrick Antolin and Kazunari Shibata of Kyoto

University, Japan, simulated the two processes, they


For new stories every day, visit www.NewScientist.com/news

Your bullying boss really is an idiot GOT a bully for a boss? Take solace in research showing that leaders who feel incompetent really do lash out to temper their own inferiority. When bosses feel they can't legitimately show superiority and competence, they take people down a notch or two, says Nathanael Fast of the University of Southern California in Los Angeles. To see if a bruised ego can cause aggression, Fast and his colleague Serena Chen manipulated people's sense of power and self-worth

Penetrating the haze at the centre of the galaxy WHAT is causing a mysterious kicked out by the supernova. Instead, the signal could be "haze" of radiation at the centre of produced by amplified cosmic This configuration - plus the particularly high turbulence in the Milky Way? It may be a load of rays generated when particularly monster supernovae kicking out the galactic centre caused by the large stars explode, says Peter radiation which is then amplified Biermann of the Max Planck high concentration of stars - may be increasing the energy of the by magnetic stellar winds and Institute for Radioastronomy in cosmic rays, says the team. They turbulence near the galaxy's core. Bonn, Germany, and colleagues. have submitted the paper to The The centre of our galaxy has In 2003, the Wilkinson a high number of massive stars Astrophysical Journal. Microwave Anisotropy Probe compared with elsewhere. Dan Hooper at the University found a patch of particularly energetic microwave radiation of Chicago points out that while These stars are surrounded by particularly strong magnetic in the centre of our galaxy 足 it's prudent to consider scenarios dubbed the "WMAP haze". It other than dark matter as a cause, stellar winds. At the star's polar was proposed that this could be regions, the wind's magnetic field very little is known about the caused by collisions of a new type is parallel to the direction of travel inner region of our galaxy and of dark-matter particle. of any escaping cosmic rays the magnetic fields there.

by asking them to write about occasions when they felt either empowered or impotent and then either competent or incompetent. Next. the volunteers selected a

Looming sounds boost night sight

punishment suitable for students who gave wrong answers in a test. with a choice of horn sounds ranging from 10 decibels to a deafening 130 decibels. The volunteers who felt the most incompetent but most empowered picked the loudest punishments 71 decibels on average. Workers who felt up to their jobs selected quieter punishments, between SS and 62 decibels, as did those primed to feel incompetent yet powerless (Psychological Science, 001: 10.11111

j.1467-92BO.2009.024S2.x). Flattery helped. When Fast and Chen praised the leadership skills of their volunteers, the aggressive tendencies all but disappeared.

FOOTSTEPS behind you in a dark alley get louder. By the time you spin around, your brain's vision circuits have already boosted their sensitivity, primed to pick out your pursuer in dim light. That's the suggestion from a study of responses to "looming" sounds. Vincenzo Romei of the University of Glasgow, UK, and his colleagues played 15 volunteers a range of sounds. Some sounded like they were approaching, while others seemed to be receding or stationary. At the same time, transcranial magnetic stimulation was used to excite the brain's visual cortex, priming the volunteers to see illusory spots of light called phosphenes. The more sensitive the visual cortex is, the higher the chance of seeing them. The looming sounds had by far the strongest effect, making people see phosphenes in 70 per cent of trials, compared with 50 per cent for stationary sounds and 45 per cent for receding ones (Current Biology, DOl: 10.1016/ j.cub.200g.09.027). A visual cortex that responds to sounds could have evolved because it would help us to spot threats more quickly in the dark, suggests Romei.

Well-endowed ducks less prone to f lu BIRD flu may be a sexually transmitted

bigger the phallus, the more complex

infection - at least in ducks. That's

the vaginal anatomy of the female,

the suggestion of an analysis of

to make insemination by unwelcome

flu prevalence and mating behaviour.

partners less likely.

Ducks are rare among birds in having

The team found that the duck

a penis, and it turns out that less

species with the shortest penises

well-endowed species have a higher

had the highest flu levels (Behavioral

incidence of flu infection. Gergely Hegyi at Eiitviis Lorand University in Budapest, Hungary, and

Ecology, 001: 10.1093/behecol

arp133). The researchers do not have an explanation for the finding.

colleagues compared data on the

"This is intriguing and a bit counter足

prevalence of flu strains in different

intuitive because a long phallus

duck species with the anatomy of

prolongs copUlation, and forced

their reproductive parts. Because of

copulations characteristic to species

the presence of a phallus, male ducks

with a large phallus should further

often force sex on females. The

promote virus transfer;' says Hegyi.

24 October 2009 1 N ewScientist 1 17


-

o

-.

-

I


2030 we expect e n e rgy d e m a n d to be 35 percent h i g h e r than it was i n t h e year 2005, d riven largely by people i n the d eve l o p i n g world seeki ng h i g h e r standards of l ivi n g . By

Meet i n g t h i s g rowi ng l o n g -term demand req u i res that we develop a l l eco n o m i c sources of en ergy - o i l , natural gas, coal , n uclear and alternatives .

M any parts worki ng tog ether 足 the on ly way to so lve the worl d 's energy chal lenges . This g lobal energy demand challenge is matched by a g lobal environmental challenge c u rb i n g greenhouse gas emissions and addressi n g the risks of c l i m ate change. No s i n g l e energy tech nology available today solves t h i s dual challenge, and it is very l i kely no s i n g l e energy tec h n o logy w i l l solve it tomorrow. We need an i ntegrated set of solutions, powered by technology and i n n ovation - ran g i n g fro m prod ucing energy more effect ively. . . to using it more efficiently. . . to i m p rovi ng exist i n g alternative sou rces o f energy. . . to developing new optio n s . Exxo n M o b i l i s worki ng to h e l p meet the worl d 's en ergy challenges - i nvest i n g more t h a n

US$ 100

b i l l io n i n a d d i t i o n a l s u p p l ies over the next fo u r years , deve l o p i n g effi ciency

tec h n o l ogy options l i ke l i t h i u m - i o n battery fi l m to s peed the adoption of hybrid veh i c l e s , and test i n g n e w carbon captu re tec h n o l og i es t h at cou l d red uce emissions s i g n ificant ly. Because only by i nteg rating all of our energy options - new sources and new tech nologies w i l l we so lve our dual energy and enviro n m e ntal challenges.

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R ES EA R C H T H AT MAY C H A N G E YO U R WO R L D The N o rweg ian U n iversity of Science a n d Technology [ N T N U ) i s N o rway's premier academic i n stituti o n for tec h n o logy a n d the natural sciences, with equa lly stro ng progra m m es in the social sciences, the a rts a n d h u m a nities, medicine, a rc h itecture a n d f i n e a rt. The u n iversity's cross-discipli nary research resu lts in i n n ovative breakthroughs a n d creative solutions with far-rea c h i n g social a n d economic i m pact. Visit www. ntn u . e d u


TECHNOLOGY

For daily technology stories, visit www.NewScientist.com/technology

How to tu rn pig足 poop i nto power

I nternet to get a go-faster switch A NEW breed of optical switch could give a dramatic hike to online data speeds. One of the biggest obstacles to ultrafast broadband has been the prevalence of copper wires used to connect homes to local telecom exchanges. It has been too expensive to replace that copper with faster glass optical fibre cables, while cheaper plastic optical fibre (POF) isn't yet up to the task. Now researchers with Polycom, a pan-European project funded by the European Union, have brought POF closer to ousting copper. They have produced an optical switch which is so quick and precise that it enables a technique called time division multiplexing to be used on POP. The technique allows separate data streams to be transmitted simultaneously, allowing POF to carry comparable amounts of data to copper.

1120 IT security breaches in the last two years at NASA resulted in unauthorised access to data or the installing of malicious code

systems such as anaerobic digesters or incinerators. In anaerobic digestion, bacteria break down waste material by STINKING lagoons of pig manure warming it in an oxygen-free created by thousands of animals vessel, releasing methane in giant hog farms can pollute which is used in gas turbines. Incinerators burn material to boil rivers, poison groundwater and pump out clouds of methane and water and drive a steam turbine. carbon dioxide. So finding The team, led by Trakarn alternative uses for the slurry Prapaspongsa at Aalborg to generate electricity, say - makes University, found that for high足 a lot of sense. The problem was efficiency energy production, that no one has been certain anaerobic digestion is the answer. which way of doing it makes the But if minimising greenhouse gas most electricity for the least emissions takes priority, the best greenhouse gas production. option was to separate the solid Now a Danish team has analysed from the liquid waste, dry the the various ways in which firms in solids and incinerate them (Waste that country treat pig manure and Management & Research, DOl : use it to generate electricity in 1O.1177/0734242X09338728).

"Searc h i n g o n l i ne m ay be a fo rm of bra i n exe rc i se"

Rout i n e i nter n et u se, s u c h a s we b searching, m ay b oost b ra i n a ctivity, says Teena Moody,

a researcher t h e U n iversity of Cal ifornia, Los Angeles. S h e recko n s s u c h a ctivity c o u l d h e l p d e l ay t h e o nset o f dement i a ( The Daily Telegraph, Lo n d o n, 19 Octob e r)

24 Octo ber 2009 1 NewScientist 1 21


TECHNOLOGY

Industrial robot hones vi rtual autopsies Autopsies a re messy, u psett i n g for the fa m i ly, a nd you o n ly get o n e c h a n ce to see the body w h o l e . ''V i rtual a uto psi es" ta ckl e a l l t h ree p roblems at o n ce Paul Marks

THE small industrial robot that dominates the room is in many ways much like any other. A robotic arm smoothly wields grippers and probes - always accurate and never tired. But rather than working on cars or computers, this robot is processing human corpses.

A team of forensic pathologists at the University of Bern in Switzerland reckon it could make autopsies more accurate and also less distressing for families. The researchers are already pioneers of virtual autopsies, or "virtopsies", which use non­ invasive imaging of a body inside and out rather than the radical post-mortem surgery typically

Anatomy of a virtopsy

Com b i n i n g robotics and sophisticated scanning techniques makes for an accu rate

way to determ i n e cause of death without cutting up the corpse

BODY I NTERIOR

BODY SURFACE

• • • •

• • • •

Robot captures 3D su rface deta i l s using stereo cameras

Autom ated CT scan

· · · ·

· · · ·

. T Disease or d amage to bon es, soft tissue and organs recorded

Bruise wounds and identifyi ng ma rks recorded

t : ..... ... . .. .

,. . ..... ..... ..... ..

Complete (internal and external) 3 D model of b� dy generated •

Robot performs image -guided need le bio psy . ·

t

Tissue sample a � alysis recorded ·

t

CAU S E O F D EATH D ET E R M I N E D Models and data stored for future reference 22 1 NewScientist 1 24 October 2009

used to determine cause of death. Now they are using a robot, dubbed Virtibot, to carry out parts of that process, making it more reliable - and standardised. Their virtopsies combine 3D imaging of a body's surface with a CT scan of its interior anatomy. The result is a faithful, high­ resolution virtual double of the corpse (see diagram). This double can be used to accurately determine what killed someone. And it's a more tactful approach: only needle biopsies are used to sample tissues, leaving a body essentially undamaged. "Currently, organs are taken out and sliced for analysis of tumours and lesions, but if something is overlooked you have no chance of seeing it again," says team member Lars Ebert. "All you have afterwards is a huge pile of organ slices." By automating virtopsies, he now hopes to free the post­ mortem from the influence of the unavoidable human failings of pathologists, which can affect conclusions about cause of death. "Too much of an investigator's autopsy results depend on their ability to describe in a report what they see - and they may overlook things," says Ebert. "We want to make the whole procedure more objective and generate digitally stored data that can be re-examined 20 or 30 years later." The current virtopsy procedure begins with a surface scan of the body. When a corpse is placed on the table in front of it, the robot places markers on the skin that help calibrate the surface scan and match it up with later internal

scans. It then captures a 3D colour model of the body to a resolution of just 0.02 millimetres, using stereoscopic cameras and a projector that casts a mesh pattern onto the body (see picture, above). This model can be twisted and turned on a computer screen, revealing injuries, tattoos and other identifying marks in detail. Being able to process those traces digitally is a boon. In one case, recording the pattern of a car fender stamped onto a person's skin helped reconstruct the accident that killed them.

"This virtual body-double can be used to accurately determine what killed a person" Furthermore, scanning without robot assistance is a cumbersome process in which someone must carefully position an unwieldy tripod at different points around the body. Virtibot, able to control its movements with great precision, simply glides over the body to build up the 3D picture. After the surface scan, the table on which the body lies slides through a CT scanner, which takes high-resolution X-ray slices of the


For daily technology stories, visit www.NewScientist.com/technology

Sti n gs fro m t h e sea g ive a pa i n -free kick to ski n crea m MIXING stinging cells from sea

Applying the cream to the skin

anemones into skin cream sounds like

triggers the stinging cells. In firing,

a bad practical joke. But anaesthetic

they act like tiny pumps, drawing in

cream that uses this novel approach

more of the drug from the cream and

to painlessly inject a painkiller

sending it through the needle. Each

is moving through clinical trials.

"needle" is just a few micrometres

Anemone stings could also offer

thick, making the injection painless.

needle·free insulin to diabetics. The stinging cells, or cnidocysts,

One square centimetre of cream· coated skin can contain as many as

of sea anemones, jellyfish and other

a million tiny needles, of which one­

cnidarians work like tiny harpoons

third will be pointing the right way

when triggered by physical contact.

to fire their needles into the skin.

They shoot out a hollow thread that

Last week, Nano(yte concluded

delivers poison into the unfortunate victim through a sharp tip. Nano(yte, based in Or Akiva, Israel, uses stings "harvested" from tank­ Scanning, not scratching, the surface

dwelling A iptasia diaphana sea

"Applying the cream to the skin triggers the stinging cells, which send the drug through the needle"

anemones, native to the Red and

entire body, providing a way to be left largely to its own devices. see damage or disease in organs "These people are already dead, or bones. In the case of a car-crash so there is no way we can injure them further," says Ebert. "That victim, being able to see the patterns of breakage, and damage means we can use a cheaper industrial robot, drawn from to bones, can also help work out exactly what happened. the automobile industry." So far, Virtibot has aided Finally, after analysis of the virtopsies in 52 real cases, 3D model and the internal and external scans, a needle biopsy including 26 road deaths, 10 by can be used to gather samples impacts from a blunt object, six from inside the body if further knifings, five shootings, and two information is required. Wielding throttlings (The International a fine needle, the system uses live Journal ofMedical Robotics and Computer Assisted Surgery, CT-scan images to grab a biopsy sample from precisely where it is DOl: 1O.1002/rcs.285). needed. That might be a sample of In 19 cases, 3D surface scans fluid from the lungs of a victim of were used to make virtual reconstructions of the attack or drowning, or a piece of liver to look for signs of disease or toxins. accident accurate enough to be Such biopsies normally require admissible in the Swiss courts. However, the president of the someone to expose their hand to the scanner's X-rays. A robot has no UK's Royal College of Pathologists, such worries. And, like the robots Peter Furness, says that much used in surgery on the living, it is longer term comparisons of more than capable of using small virtopsies with conventional procedures are still needed. "The tools with great precision. circumstances where this might Despite its impressive be valuable are not well defined, dexterity, Virtibot wasn't built with surgery in mind. Robots the reliability of the approach is used for precision surgery on unclear and the cost can be considerable," he says, adding the living must let surgeons maintain absolute control at that studies to work out just when a conventional autopsy is all times, for safety reasons. essential are under way. • Once given a task, Virtibot can

Mediterranean seas. The firm won't

phase 11 clinical trials in the US of a

say how, but it can provoke the

cream containing lidocaine, a local

anemones into releasing filaments

anaesthetic used by dentists. The

stuffed with stinging cells, which can

firm hopes to launch cosmetics, such

be gathered without harming the

as "anti-ageing" treatments, in 2010.

animals. "It's a bit like milking a cow," says Yaron Daniely, (EO of Nano(yte. The stinging cells are then processed to denature and extract their toxic proteins. That, and the fact

Preliminary work with mice suggests anemone stings can also inject insulin, says Daniely. "It is exciting that this approach has reached phase 11 trials," says

that the species is not toxic to humans,

Mark Prausnitz, a drug delivery

makes them safe, says Daniely.

expert at the Georgia Institute of

The stinging cells are carefully

Technology in Atlanta. Pharmaceutical

mixed into a cream containing the

applications are more strictly

drug to be injected into the skin,

regulated than cosmetic ones, though,

some of which diffuses into the cells.

he points out. Colin Barras •

Try milking that

24 Octo ber 2009 1 NewScientist 1 23


TECHNOLOGY Laser m i crosco pe ta kes a i m at extraterrestri a l l ife fo rms MICROSCOPES revolutionised the study of life on Earth. Now a rugged, easy-to-use instrument is aiming to be equally influential in the search for alien life in locations such as the oceans beneath the icy surface of Jupiter's moon Europa. The hunt for signs of extraterrestrial life usually focuses on detecting molecules associated with living organisms. Direct observation through optical imaging would be more conclusive, so Hans Kreuzer and Manfred Jericho at Dalhousie University in Halifax, Nova Scotia, Canada, and their colleagues have taken a different approach. They have built a robust microscope that can be dunked into water to detect any microscopic life forms that may be swimming or floating there. Called the digital inline holographic microscope, it consists of a pair of watertight compartments separated by a chamber into which water can flow. One compartment contains a blue laser that is focused onto a pinhole­ sized window facing into the water.

Opposite the pinhole, in the second compartment, is a digital camera. As the laser light hits the pinhole, it generates a spherical light wave that spreads out through the water. If it hits a microscopic object - a bacterium, say - further diffraction occurs. The spherical wave and the diffraction pattern created by the

microscopic object interfere to create a pattern that is captured by the camera. This interference pattern is essentially a hologram of whatever is in front of the pinhole. Kreuzer has patented an algorithm that can reconstruct the objects that created the interference pattern within milliseconds. In this way the camera can produce real-time images of any object in the water if they are larger than about 100 nanometres across. To test the instrument, the team

took it to the extreme environment of Axe I Heiberg island in the Arctic, where a robotic vessel immersed it in a lake (Planetary and Space Science, DOl : 1O.1016/j.pSS.200g.07.012). "We saw all sorts of critters we didn't know were there," says team member Jay Nadeau of McGill University in Montreal, Canada. Nadeau says that the rugged, lightweight device can be easily transported, and does not require constant intervention to obtain clear images. It has a wide angle of view and a large depth of field, � which together allow it to follow objects as they float in the 7-cubic­ millimetre chamber in front of the pinhole. "You can be absolutely certain if something is alive and swimming," says Nadeau. Chris McKay of NASA's Ames Research Center in Moffett Field, California, who worked on the Phoenix mission to Mars, is intrigued by the work. "While I would not argue that a microscope is the next instrument to send to Mars or Europa, it is clear that eventually we must send microscopes," he says. "The design here is pretty clever and well suited for a flight instrument." Anil Ananthaswamy • Z

M o d ern p h oto-sha ri ng with an o l d -sch o o l twist

idea of using spatial regions, like auras,

IT'S a latter-day social affliction: you

says Newcastle's lead researcher

visit friends or family, only for them to

Christian Kray, is the tactile nature

whip out a laptop and run a seemingly

of holding a photographic print. The

displayed a different barcode-like

around the table;' says Kray. An "aura"

"People really enjoyed sharing pictures this way, with everyone

in the middle of the table was used to

getting the photos at the same time

upload pictures to the whole group,

and all having something to hold;' says

while a concentric outer aura was for

Kray, though some felt a lack of control

downloading and viewing them.

over downloads. "They thought people

The team wrote software which

could elbow their way into the pub and steal your compromising photo."

endless photo slide show -perhaps

team aimed to create an interaction

pattern at the top of every phone

using an online outfit such as Flickr

which "resembles the passing around

screen, so that an overhead camera

future smartphones, using their

or Picasa. But for those people used

of stacks of paper photographs".

"The inner 'aura' is where you upload pictures to the group and the outer aura is for looking at them"

neighbouring phones, says Kray.

to savouring prints as they are passed

First, they tried simply sitting

around, such shows can be about as

groups of five people at a table and

compelling as "death by Powerpoint".

asking them to swap digital photos

Help could be at hand, however. Researchers at Deutsche Telekom

one-to-one on their camera·phones

The system could be built into cameras to seek out barcodes on

using Bluetooth. "It didn't work;' says

"This sounds like a very interesting technology and it may have other applications -like sharing business information in meetings," says Robert

in Germany and the University of

Kray. "Some people paired up, leaving

could recognise which aura each

Caunt, a consumer electronics expert

Newcastle in the UK have dreamed

some people on their own."

phone was in. When a phone was

with London-based market analyst

up a curious cellphone·centred way

To foster greater group cohesion,

placed in the upload aura, the camera

CCS Insight. "But I'm not sure sharing

triggered a Bluetooth-enabled PC to

photos is what it will be best at. After

to bridge the gap between what they

they looked at a method that could

call the Kodak and Flickr generations.

share photos with all group members

broadcast its photographic contents

all, photo printer sales are still fairly

What the Kodak generation miss,

simultaneously. "We came up with the

to the other smartphones.

strong." Pa ul Marks .

24 1 NewScientist 1 24 October 2009


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OPINION

The truth about honeybees Heard what E i nste i n sa i d a bout h u m a n s havi n g fou r yea rs to l ive if the bees d i ed out? Wel l h e d i d n't and we won't say Marcelo Aizen and Lawrence Harder A MOVIE called Vanishing of the Bees opened in cinemas across the UK earlier this month. It's a feature-length documentary about the "mysterious collapse" of the honeybee population across the planet - a phenomenon that has recently attracted a great deal of attention and hand-wringing. The idea that bees are disappearing for reasons unknown has embedded itself in the public consciousness. It is also a great story that taps into the anxieties of our age. But is it true? We think not, at least not yet. First, the basics. Pollination by bees and other animals - flies, butterflies, birds and bats - is necessary for the production of fruits and seeds in many wild and cultivated plants. More than 80 per cent of the planet's 250,000 species of flowering plants are pollinated by animals. Agriculture is a large-scale beneficiary of these pollination services, so claims that pollinators are in decline have triggered alarm that our food supply could be in jeopardy, that we may be on the verge of a global "pollination crisis". Claims of such a crisis rest on three main tenets : that bees are responsible for the production of a large fraction of our food; that pollinators are declining worldwide; and that pollinator decline threatens agricultural yield. Numerous scientific papers, many media stories and even a European Parliament resolution in 2008 present each of these as an uncontested truth. But are they? 26 1 NewScientist 1 24 October 2009

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nearly 2.5 billion tonnes of food Our analysis of data from a year, about a third of global the Food and Agriculture Organization of the United agricultural production. However, Nations reveals a different few of these crops depend on perspective on the pollination animal pollination completely, crisis - one that is less catastrophic owing largely to their capacity than that depicted in the movies for self-pollination. (Current Biology, vo1 18, p 1572, On top of that, production and vo1 19, p 915). of many staple foods does not depend on pollinators at all: The first tenet - that bees are responsible for the production carbohydrate crops such as wheat, rice and corn are wind-pollinated of a large fraction of our food - is simply untrue. Pollinators are or self-pollinated. If bees disappeared altogether, global important for many crops, but it is a myth that humanity would agricultural production would starve without bees. About 70 per cent of the 115 most "Pollinators are important productive crops, including most for many crops, but it is a fruits and oilseeds, are animal­ myth that h umanity would pollinated. These account for starve without bees"

decrease by only 4 to 6 per cent. What of pollinator decline? Claims of global bee disappearance are based on collections of (often extreme) regional examples, which are not necessarily representative of global trends. These examples tend to come from parts of Europe and North America where little natural or semi­ natural habitat remains. Stocks of domesticated honeybees, the most important crop pollinator of all, have also decreased considerably in the US and some European countries in recent decades. However, these declines have been more than offset by strong increases in Asia, Latin America and Africa. Indeed, the number of managed honeybee hives worldwide has increased by about 45 per cent in the past five decades. There have also been scare stories about "colony collapse disorder" and the spread ofVarroa mites in the US and Europe. Again, these are real phenomena, but they are short-term blips rather than the driving forces of long­ term trends. Instead, the long­ term declines seem to be consistent with the economic dynamics of the honey industry, which seems to be shifting to developing countries in search of cheaper production. Finally, does a low abundance of pollinators significantly affect agricultural productivity? It is true that a lack of pollinators, especially bees, can limit the yield of many crops and wild plants. It is also true that the yields of many pollinator-dependent crops have


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grown more slowly than that of most non-dependent crops. However, contrary to what we would expect if pollinators were in decline, the average yield of pollinator-dependent crops has increased steadily during recent decades, as have those of non-dependent crops, with no sign of slowing. Overall, we must conclude that claims of a global crisis in agricultural pollination are untrue. Pollination problems may be looming, though. Total global agricultural production has kept pace with the doubling of the human population during the past five decades, but the small proportion of this that depends on pollinators has quadrupled during the same period. This includes luxury foods such as raspberries, cherries, mangoes and cashew nuts. The increased production of these crops has been achieved, in part, by a 25 per cent increase in cultivated area in response to increased demand for them. This expansion may be straining global pollination capacity, for two reasons. Demand for pollination services has grown faster than the stock of domestic honeybees, and the associated land clearance has destroyed much of the natural habitat of wild pollinators. The accelerating increase of pollinator-dependent crops therefore has the potential to trigger future problems both for these crops and wild plants. These problems may grow as decreasing yields of raspberries, cherries and the rest prompt higher prices, stimulating yet more expansion of cultivation. So although the current pollination crisis is largely mythical, we may soon have a real one on our hands . • Marcelo Aizen is a researcher at the National Scientific and Technical Research Council of Argentina, Lawrence Harder is a professor of pollination ecology at the University of Calgary in Alberta, Canada

One m i n ute with ...

Jeff Greason O n e of the lead i n g l i g hts of the private space i n d u stry a rg u es that NASA m u st kee p i nvest i n g in h u m a n space exp l o rati o n

What can NASA do to improve?

NASA should have a technology road map: it doesn't have a plan saying, "These are the capabil ities we have today, these are the capabil ities we want tomorrow, and how are we going to get there from here?" Which cutting-edge technologies should NASA develop first?

The very fi rst element would be a technology for the handling and storage of propellant in space, If we had such a "gas station" it would significantly change the game in terms of what you cou l d do: it would let you launch a much more capable, bigger mission with the same-size launchers, If you use chemical rockets, you want to be able to manufacture that propellant at your destination, That saves a huge chunk of initial mass because you don't have to ta ke the propellant with you to get you back to Earth, Then there's a whole bunch of ideas for advanced space propUlsion, An ion engine called VASIMR is a perfect example, What surprised you most i n your work with the White House's Augustine Committee?

We hoped to find a way for NASA to do g reat and wonderfu l things within their current budget but we rea l ly didn't And it wasn't for lack of trying, Over the long term, if you're not going to make the budget go u p, and you want to do someth ing great you have to lower the fixed costs,

PROFILE Jeff Greason is CEO of XCOR Aerospace and sits

on the US's Augustine Committee, which reviews NASA's plans for human space flight He spoke at a recent Space Investment Summit in Boston

wrong or right with NASA, the qual ity of the people isn't a problem, NASA has real ly good, motivated people, One contri buting factor could be that we're not asking them to do the right job, But the bigger question is, do we rea l ly want to spend whatever it takes, hundreds of b i l l ions of dollars, a l l so we can race to plant a flag for reasons of national pride? But you don't think we should discontinue human space exploration?

What can NASA do to cut costs?

There was one option which involved relyi ng on expendable launch vehicles - the Delta IV and Atlas V rockets - the cost of which would be shared with the Department of Defense, That does have the potential to change the fixed costs of the human space flight programme, I s NASA sti l l capable o f inspiring achievements l i ke the Apollo moon land ings?

It's easy to say, and I've sa id it myself, that we j ust don't have the NASA we used to have, so we can't do the things we used to do, But whatever is

I think one of the most i m portant findings that we made on the Augustine comm ittee is that there is an underlying reason why we should be doing human space exploration, which is that we ought to extend permanent human civil isation beyond this planet and that is an incred ibly i m portant human endeavour, Stephen Hawking ca lls for moon and Mars colonies, To my mi nd, I can't see why we would n't do it It's the only way to create a future in which humans can l ive somewhere other than Earth, Robots will help, but you don't learn how to l ive in places by j ust sending robots, Interview by David Shiga

24 Octo ber 2009 1 NewScientist 1 27


OPINION LETTERS Persistent populace? From George Wiman An optimistic Jesse Ausubel tells us we are so clever that we will always figure out a way to beat Malthusian predictions of population catastrophe (26 September, p 38). It has indeed worked so far, as exponential population growth smacks up against merely linear resource growth. In the end, though, he's counting on us finding increasingly clever ways to balance on the branch that we're sawing off. He may be right, of course. If so, perhaps we could all meet and discuss it one day over a nice plate of jellyfish with genetically engineered yeast sauce on the side. Delicious. Normal, Illinois, US From Simon Dicker Bob Holmes's article on the effects of global warming paints a bleak picture of the Earth's future, one in which, as researcher David Jablonski asserts, the weeds and the cockroaches will do well, and humans won't (3 October, p 32). Holmes describes these species as able to exploit disturbed environments - but this is

exactly what humans do too. As a species we are massively overusing our planet and I agree that mass starvation will occur, but evolution is about survival of the fittest. After we have wrecked the planet through global warming and overconsumption I think that the most war-loving I

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humans will still be around in huge numbers, sharing Earth with the mosquitoes, cockroaches and Japanese knotweed. Philadelphia, Pennsylvania, US From GeoffKirby Paul and Anne Ehrlich begin their attack on population growth by drawing attention to the "increasing shortages of food, water and other resources and growing numbers of hungry

Enigma N u m be r 1568 Odd puzzle ALBERT HAD DAD

In this m u ltiplication sum the dig its have been replaced by letters and dots. Different letters stand for different digits, the same letter sta nds for the same digit each dot can be any digit and leading digits cannot be zero. What is the six-figure odd PUZZLE? WIN

O D D P U Z Z L E

£15 w i l l be awa rded to the sender of the first correct answer opened on Wed nesday 25 November. The Ed itor's decision is final. Please send entries to Enigma 1568, New Scientist Lacon House, 84 Theobald's Road, London WClX 8NS, o r to enigma@newscientist.com (please include you r posta l address). Answer to 1562 Same u nused dig its: The largest and smal lest of the six squares were 8649 and 2809 respectively. The winner Diane Erwin of Sunderland, Tyne and Wear, UK 28 1 NewScientist 1 24 Octo ber 2009

people" (26 September, p 36). sufficient. Bees' vision is based However, the charts that close in the ultraviolet, and shows part one of your "Blueprint for flowers as star-bright against a a better world" series show that grey background. hunger, malnutrition, extreme A bee colony requires a great deal of organisation. The waggle poverty and child mortality have reduced since the early 1990S, dance and pheromones are not enough to direct day-to-day and that food supply and access to clean water for drinking actions; there must be another method of communication. It and sanitation have improved (12 September, p 30). GDP per might be that bees communicate capita is steadily rising even in using their front legs. I have seen sub-Saharan Africa, which is the them stand on their four back legs benchmark for deprivation. and rapidly rub their front legs Additionally, Bj!1!m Lomborg together in what could be a form wrote in his book The Skeptical of sign language. Or perhaps they Environmentalist that the calories rub their antennae together for consumed per capita per day in the same purpose. Any of these the developing world have risen methods could be used by the bees to give directions to food steadily since 1960. What a shame that an otherwise sources, if required. interesting article should be based Until there is a better explanation of the waggle dance, on such unfounded premises. Weymouth, Dorset, UK perhaps we should accept that the girls just like to dance. Can't we at least acknowledge the possibility that bees have higher emotions What's the buzz? symbolised by dance? With my From Bill Summers experience of bees, I can. Sturminster Newton, Dorset, UK Caroline Williams casts doubt on the received wisdom that the bees' waggle dance is about From Margaret Woodhouse communicating the direction The discussion on the interpretation of the bees' and distance of a source of food (19 September, p 40). Having kept waggle dance missed an bees for 37 years, I concur. important point. Researchers use an observation hive with a Waggle dances can be seen most frequently in early spring. glass panel, which allows people to view the bees' movement. If their purpose is to provide directions, why should that be so? Within a conventional hive Foraging sources, and therefore there is almost total darkness, their location, change throughout so it is inappropriate to consider bees as "watching" the waggle the year, so dances pointing dance. Researchers need to other bees towards them should be equally frequent, whatever consider information systems other than sight to understand the season. how bees communicate. Other observations are also at odds with the conventional Cardiff, UK explanation of the waggle dance. When I have had occasion From Ken Green to rotate a frame from a hive I kept bees for five years. My hives were set in a line in front of a huge from vertical to horizontal, bees that were already dancing laurel hedge which faced due south. Some 550 metres distant, continued to do so. This change at 45 degrees to the line of hives, in orientation, which could only and behind a large block of confuse their directions, seems stables, was a nectar treasure not to affect the dance. trove of lime trees. When it comes to locating To get to the trees, navigating forage sources, vision ought to be


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around the large obstacle, the bees would fly along in a line, before changing direction when they encountered "marker" bees hovering about 1.5 metres above the ground at two points along the route. Penpathy, Cornwall, UK

No second chance From Charles Goodwin I agree with Harriet Coleman (22 August, p 24) that the debate about global warming is really about preserving our way of life, and that "in the worst case we will be trying to save enough civilisation not to have to start again from the Stone Age". However, I would also add that the chances of us being able to start again from the Stone Age are remote, since we will have blown what is most likely our only chance. Technological civilisation, as I think astronomer Fred Hoyle once pointed out, is almost certainly a one-shot affair, since it entails using up all the easily available resources and thereby making it virtually impossible for any subsequent civilisation to arise that uses anything other than muscle power, wind, water and burning wood. Wellington, New Zealand

Michael Le Page replies: • According to the child survival hypothesis, the less likely children are to die, the fewer children their parents have, so reducing child mortality rate eventually lowers the fertility rate. The short -term effect of improving child health will be to increase the population, but in the long term it helps reduce population growth.

Relative earnings From Neil Buchan The chart on "extreme poverty" at the end of part one of your "Blueprint for a better world" series errs in using the classification of earnings below $1.25 per day (12 September, p 30). This amount, off the tourist trails, in northern India or Chad, for example, would probably buy a whole family a decent meal, but in Europe or the US they would need much more than that for the purpose. It is not sensible to assess poverty in these monetary terms; it needs to be compared with the

Geo war

local cost of living. I concede that this is often difficult to define, but "$1.25 per day" doesn't mean anything without comparison. Reading, Berkshire, UK

From AOtson Bailes Another plea in your pages for geoengineering (12 September, p 34) makes me wonder if I am alone in my concern about the potential for warlike abuse of these techniques. Several of those now discussed could be used to intentionally damage territories and populations by inciting droughts or floods, or by changing sea or air chemistry. The 1978 Environmental Modification (ENMOD) convention banned hostile use of geoengineering techniques. With talk of implementing these technologies, isn't there a case for digging out and updating that convention? Reykjavik, Iceland

Improving Earth

You dirty rat

From Karl Jaeger I found your "Blueprint for a better world" series interesting (12, 19 and 26 September, and 3 October), as I am involved in

From Mark Allan Barnes In Henry Nicholls's article on taming wild animals, I was intrigued to read that "You can do anything with the tame rats . . .

Mortality rate From Rosie Caswell In his article on genetic engineering, Michael Le Page claims that genetically modified Golden Rice will "help to improve health and reduce child mortality, which will ultimately contribute to a reduction in population growth" (12 September, p 37). I disagree. Surely the population will increase if people live longer because they are healthier, and sick children do not die but live to a ripe and productive age. Harlow, Essex, UK

an endeavour called Our Future Planet, which has similar aims. To reduce population by 50 per cent while also offering children and parents a better interactive future, I suggest a family system in which a couple has one child and then joins with another couple with one child. The children have companionship, and the burden of raising the children is shared between four adults. Also, if one couple should ever split, the children may still have three adults for support. To immediately reduce the pollution due to cars, without the need for new types of vehicles or fuels, we could raise the legal driving age to 21. This would not only reduce greenhouse gas emissions, it should also eliminate the injuries and deaths now caused by young drivers. Bath, Somerset, UK

you can move their arms and legs" (3 October, p 40). Did those rats that were bred to be aggressive also have arms? Was there interest from the military in the idea of equipping them with tiny weapons? Cholsey, Oxfordshire, UK

Elementology From Philip Stewart Copernicus was a great scientist and should be commemorated, though Aristarchus of Samos came up with the heliocentric theory 17 centuries earlier. But it seems perverse to name element 112 after Copernicus when there are contributors to the periodic system who have not yet been honoured (25 July, p 7). Bars Hill, Oxfordshire, UK

For the record • We misspelled John (ockcroft's

name in our editorial on ITER, sorry (10 October, p S). • Apologies also to Georgios

Yannakakis whose name we misspelled in our article on adaptive computer games (10 October, p 21).

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24 Octo ber 2009 1 NewScientist 1 29


OPINION ESSAY

Ea rthl a treasu ry for a l l to l ive upon Fro m stock ma rkets to measu r i n g G D P, co nve nt i o n a l eco n o m i cs i s i n a m ess, Do w e n e e d ra d i c a l n e w ways to assess eco n o m i c activity, asks M i ke Holderness inaccurate estimate of public well-being. HOW much political power can one number exert? Gross domestic product (GDP) is a This clash between the economic measures of socio-economic phenomena and public strong candidate for the world's most potent numerical indicator. Politicians use it to rank perception of the same phenomena spurred President Nicolas Sarkozy of France into action. states in order of production, and to guide policies to maintain their place in the pecking Early last year, he asked economists Joseph Stiglitz of Columbia University in New York, order. Its year-on-year changes dictate Amartya Sen of Harvard University and Jean足 whether an economy is "in recession", which Paul Fitoussi of Sciences-Po (the Institute of in turn influences what you pay for the loan Political Studies) in Paris, France, to set up the to buy your home or run your business - and, Commission on the Measurement of Economic indeed, the price of fish. Performance and Social Progress (CMEPSP). But look under the hood at the factors that feed into the calculation of GDP and you'll see The commission's report was published some strange goings-on. For one thing, it's full last month, and the onset of global recession 足 of virtual production and trading. People who as determined by old-style GDP - means it is own their houses, for example, are deemed to likely to be read more widely than it might pay themselves rent, which is included in GDP; otherwise have been. The report itself says that some members of the commission it has to be this way, to keep the books tidy. believe one reason the economic crisis took Then there are the important transactions many by surprise is that " our measurement that are not included. No attempt is made to system failed us and/or. . . market participants value the services provided by the state, for and government officials were not focusing example. Fees charged by private hospitals on the right set of statistical indicators". are included, but when it comes to state-run As a result, accounting systems "did not hospitals only the goods and services they alert us that the seemingly bright growth buy in are deemed to contribute to GDP. performance of the world economy between Also unaccounted for is activity in the issues - how to measure environmental 2004 and 2007 may have been achieved at sustainability. The report notes that this "informal" economy. As well as dubious last goal will require indicators of crises such or downright illegal activities, this includes the expense of future growth". as those linked to climate change or to the The report's 12 recommendations centre things people make and do for themselves, their families and their neighbours without on changing the emphasis from measuring depletion of fishing stocks. cash necessarily changing hands. Measuring quality of life directly is not economic production to measuring human well-being, on the problems of defining Crucially, existing measures of GDP also going to be easy. In passing, the report cites fail to reflect the fact that some of the activity well-being and - perhaps the thorniest of such gems as the finding that women in that contributes to GDP does harm rather than Columbus, Ohio, surveyed about their PROFILE feelings, or " affect", while carrying out good. This distortion can encourage false choices - between promoting GDP and Mike Holderness is a writer and editor, He has different activities, felt better walking than protecting the environment, for example. when they were having sex. Puzzlingly, the written reports for the Royal Society, including So jammed roads increase GDP through the same researcher, Alan Krueger of Princeton The weather turned upside-down? Abrupt Climate Change: Evidence, mechanisms and implications, University, has also discovered that "the increased sales of fuel that is wasted, but do correlation between life satisfaction and net and edited the final report of the I nformation nothing for people's quality of life. And for affect is only 0-44" : people's description of anyone concerned about air quality, statistics Society Forum for the European Commission which ignore air pollution produce an their separate experiences does not predict 30 1 NewScientist 1 24 Octo ber 2009


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activist Gerard Winstanley's insistence that resources are " a common treasury for all to live comfortably upon" ? Any index of sustainability is bound to have little in common with the after-the-fact accounting that produces GDP, because it is, essentially, modelling the future. Here, we collide with the most miserable tool in the box of economics tricks : the measure of people's pessimism known as the discount factor. If I offer you either £5 today or £10 one year hence, you are likely to take the £5. On this basis, your discount factor with respect to me is 50 per cent per year. Even using a modest 5 per cent discount factor for future environmental damage, a million units of damage done 100 years in the future has a net present value

"An alternative economic index will have i mmense power to drive policy"

century, right up to the present day: the zero value normally ascribed to natural resources. Environmental groups promote the idea of very well how they feel about their lives. the "carbon footprint" or general "resource Yet "hedonology", as the study of pleasure footprint" as an index of sustainability. is called, remains more interesting than the But it has been left to the World Bank, often accountant's standard way of measuring well­ seen as conservative, to develop a more being, which is to ask about our willingness to radical measure it calls Adjusted Net Savings, pay cash for an equivalent experience. Other which treats resources as capital. The authors of the CMEPSP report stress efforts, such as the UN's Human Development that treating resources as assets or capital Index are, say the commission's authors, too goods " does not mean at all that we consider closely tied to GDP. that these assets should all be privately owned And what shall it benefit you to have cash or hedonic experiences now, if you know it will or submitted to market forces". Rather, many soon be all over? Proposing a sustainability of them are " collective assets that cannot be index brings us up against the core of standard managed efficiently by market mechanisms". Have we returned to the 17th-century English economics, from Adam Smith in the 18th GDP's inability to account for environmental

damage distorts economic choices

of few thousand units. The future simply disappears from capitalism's books. Whatever index is used, reducing an entire economy's performance - and especially its sustainability - to a single integer is bound to lose a great deal of information. The CMEPSP report therefore envisages a " dashboard" of measures. As it argues, "a meter that weighed up in one single value the current speed of the vehicle and the remaining level of gasoline would not be of any help to the driver". The report nevertheless acknowledges that if politicians do accept an alternative index, it will have immense power to drive policy. And prospects for acceptance turn out to be good. On 8 September, the European Commission issued a communication committing itself to "working to complement GDP and National Accounts (which presents production, income and expenditure in the economy) with environmental and social accounts". The European Commission has already adopted many of the report's proposals. Despite such hopeful signs, GDP isn't going to go away any time soon. The ratio of GDP to national debt may be meaningless, but it looks seductively like real accounting. Currency traders won't feel well-informed if they express national debt as a multiple of happiness or green prudence. Producing useful tools for guiding policy - never mind ideal ones - is going to take a while. But at the very least, exploring the CMEPSP report's recommendations will promote an interesting social and scientific discussion of what "sustainable" and "happy" mean to each of us . • 24 October 2009 1 N ewScientist 1 31


H ow d oes yo u r bra i n s l i ce a n d d i ce t i m e, a n d what ha ppens when it g oes h o rri b ly wrong? Douglas Fox i nvestigates

The time machine inside your head 32 1 NewScientist 1 24 October 2009


COVER STORY suffered by people with schizophrenia. But first, the basics. Perhaps the most fundamental question neuroscientists are investigating is whether our perception of the world is continuous or a series of discrete snapshots like frames on a film strip. Understand this, and maybe we can explain how the healthy brain works out the chronological order of the myriad events bombarding our senses, and how this can become warped to alter our perception oftime.

Spinning backwards

T

HE MAN dangles on a cable hanging from an eight-storey-high tower. Suspended in a harness with his back to the ground, he sees only the face of the man above, who controls the winch that is lifting him to the top of the tower like a bundle of cargo. And then it happens. The cable suddenly unclips and he plummets towards the concrete below. Panic sets in, but he's been given an assignment and so, fighting his fear of death, he stares at the instrument strapped to his wrist, before falling into the sweet embrace of a safety net. A team of scientists will spend weeks studying the results. The experiment was extreme, certainly, but the neuroscientist behind the study, David Eagleman at Baylor College of Medicine in Houston, Texas, is no Dr Strangelove. When

we look back at scary situations, they often seem to have occurred in slow motion. Eagleman wanted to know whether the brain's clock actually accelerates - making external events appear abnormally slow in comparison with the brain's workings - or whether the slo-mo is just an artefact of our memory. It's just one of many mysteries concerning how we experience time that we are only now beginning to crack. "Time," says Eagleman, "is much weirder than we think it is." By understanding the mechanisms of our brain's clock, Eagleman and others hope to learn ways of temporarily resetting its tick. This might improve our mental speed and reaction times. What's more, since time is crucial to our perception of causality, a faulty internal clock might also explain the delusions

Some of the first hints that we may perceive the world through discrete "frames" arrived with studies of the well-known "wagon wheel illusion", in which the wheels of a forward足 moving vehicle appear to slow down or even roll backwards. The illusion was first noted during the playback of old films, and it's due to the fact that the camera takes a sequence of snapshots of the wheel as it rotates. If the speed of rotation is right, it can look as if each spoke has rotated a small distance backwards with each frame, when the spokes have in fact moved forwards (see diagrams, pages 35 and 37). This effect is not restricted to the movies : people also report experiencing it in real life. If these observations proved to be reproducible, it would suggest that the brain naturally slices our visual perception into a succession of snapshots. So in 2006, Rufin VanRullen, a neuroscientist at the University of Toulouse in France, decided to recreate the illusion in his lab. Sure enough, when he span a wheel at certain speeds, all subjects reported seeing it turn the "wrong" way. "The continuity of our perception is an illusion," he concludes. The experiment even put a number on our visual frame rate -around 13 frames per second. But what within our brain sets this particular rate? When VanRullen measured his subjects' brain waves through electroencephalogram (EEG) electrodes on the scalp, he found a specific rhythm in the right inferior parietal lobe (RPL) -which is normally associated with our perception of visual location - that rises and falls at about the right frequency. It seemed plausible that as this 13-hertz wave oscillates, the RPL's receptivity to new visual information also shifts up and down, leading to something akin to discrete visual frames. To test this hypothesis, VanRullen used transcranial magnetic stimulation - a non足 invasive technique that can interfere with activity in specific areas of the brain - to disrupt the regular brain wave in the subjects' RPLs. > 24 October 2009 1 NewScientist 1 33


That inhibited the periodic sampling of visual in a higher processing stream. He calls these frames that is crucial for the wagon wheel the "building blocks of consciousness" and illusion, reducing the probability of seeing the reckons they underlie our perception of time illusion by 30 per cent (PLoS ONE, vol 3, p e2gu). (Philosophical Transactions ojthe Royal The subjects could still see the regular motion Society B, vo1 364, p 1887). It's an appealing idea, since patching together of the wheels, however, probably because other regions of the brain, which don't operate a chronological order of events hitting our at the necessary 13 hertz, took over some of the senses is no mean feat. Sounds tend to be processed faster than images, so without some motion perception. The case for discrete perception is far from sort of grouping system we might, say, hear a closed, however. When Eagleman showed vase smashing before we see it happen. Poppel's subjects a pair of overlapping patterns, both building blocks of consciousness would neatly solve this problem: if two events fall into the moving at the same rate, they often saw one pattern reverse independently of the other. same building block, they are perceived as simultaneous; if they fall into consecutive "If you were taking frames of the world, then everything would have to reverse at the same time," says Eagleman. VanRullen has an alternative explanation. "Perception is a seq uence The brain processes different objects within of 'on' and 'off' periods. We the visual field independently of one another, col lect i nformation thro u g h even if they overlap in space, he suggests. So the RPL may well be taking the "snapshots" d i screte sna pshots" of the two moving patterns at separate instances - and possibly at slightly different rates - making it plausible that the illusions could happen independently for each object. This implies that there is not a single "film roll" in the brain, but many separate streams, each recording a separate piece of information. What's more, this way of dealing with incoming information may not apply solely to motion perception. Other brain processes, such as object or sound recognition, might also be processed as discrete packets. To investigate, VanRullen examined another neural function, called near-threshold luminance detection. He exposed his subjects to flashes of light barely bright enough to see, and found that the likelihood of them noticing the light depended on the phase of another wave in the front of the brain, which rises and falls about 7 times per second. It turned out that subjects were more likely to detect the flash when the wave was near its trough, and miss it when the wave was near its peak. The work was published in The Journal ojNeuroscience earlier this year (VOI 2g, P 786g). "There's a succession of ' on' periods and ' off' periods of perception," VanRullen says. "Attention is collecting information through snapshots." So it seems that each separate neural process that governs our perception might be recorded in its own stream of discrete frames. But how might all these streams fit together to give us a consistent picture of the world? Ernst Poppel, a neuroscientist at the Ludwig Maximilian University in Munich, Germany, suggests all of the separate snapshots from the senses may feed into blocks of information 34 1 NewScientist 1 24 Octo ber 2009

buildings blocks, they seem successive. "Perception cannot be continuous because of [the limits of] neural processing," says poppel. "A space of 30 to 50 milliseconds is necessary to bring together in one time-window the distributed activity in the neural system."

Slices of time There's some evidence to suggest this might be what happens. In one experiment, Poppel analysed his volunteers' reaction times by measuring how quickly their eyes moved to follow a dot jumping across a computer screen. He found that their reactions seemed to follow a 3D-millisecond cycle. If the dot moved any time within this cycle, it took until the end of the interval before the volunteers would react (Naturwissenschajten, vol n p 267). A similar cycle has since been observed when volunteers are asked to discern whether an auditory and a visual stimulus are


simultaneous or consecutive - suggesting it may be at the root of Po pp el's building blocks of consciousness. The brain's effort to maintain its timekeeping has implications for understanding some diseases. Schizophrenia, for example, could arise from an inability to coordinate information arriving from different parts of the brain (see "Delusions on demand", page 36). A better knowledge of the way the brain integrates the discrete packets of information might provide further insights into this. The question of discrete versus continuous perception is not the only challenge that time presents to neuroscientists. Many, including Eagleman, are concerned with the speed at which time seems to pass in different situations. Why do we feel that some, usually frightening, experiences last longer than others, even if objectively they occurred for the same number of seconds? Eagleman experienced this apparent slowing of time

The wag o n wheel i l l us i o n If these fra mes were p layed i n succession, which way wo u l d the wheel appear to be rol l i n g - clockwise or anticlockwise?

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as an 8-year-old when he tumbled off a roof and broke his nose. There are two possible explanations, he says. It could be a facet of the memory, or it could be that his brain's processing speed accelerated under the stress, making outside events appear to slow down in comparison. Decades later, he decided to replicate his experience under carefully controlled conditions. After taking half a dozen members of his lab to a nearby amusement park and finding none of the rides scary enough, Eagleman found another outfit that offered a thrill ride known as a "suspended catch air device" which drops people from a 30-metre tower into a safety net below. To measure the speed of his plucky volunteers' perceptions, Eagleman and his team designed a wrist-worn device they call a perceptual chronometer. An LED array on the face of the device displays a flickering single­ digit number alternating with the negative of its image about 20 times per second. That would normally be too quick for a human to distinguish between the two images - you would just perceive all the elements of the LED array to be shining at once - but if their perceptual clocks of the terrified subjects accelerated even a little bit, Eagleman reasoned, the number would become visible. The results were disappointing. As expected, the volunteers overestimated the time it took them to drop into the net : they thought the fall lasted for more than 3 seconds, rather than the actual time of 2.5 seconds. But they could not discern the flickering numeral, suggesting that their perceptions had not actually speeded up. Eagleman now attributes the apparent slowing of time to a trick of memory. An intense experience, with heightened fear or excitement, rivets our attention and evokes the firing of many neurons across the brain, he says, causing us to soak up more sensory details (Philosophical Transactions of the Royal Society B, vo1 364, p 1841). Richer memories seem to last longer, he says, because you assume you would have needed more time to record so many details. "Your brain is on fire

when you're dropping," he says. "You lay down denser memory. When you read it back out, you think 'Gee, that was taking a long time'." That could explain many other temporal illusions too, such as the "oddball effect". When people see the same thing over and over (a picture of a dog flashed on a computer screen, say) and then suddenly see something different (Margaret Thatcher), the new thing seems to last longer, even if all the pictures are actually shown for the same duration. Functional magnetic resonance imaging has revealed that the brain shows a spike in activity when confronted with a surprising stimulus, suggesting that it causes a richer memory to be laid down - which, according to Eagleman's theory, explains why the experience seems longer-lasting. In total, Eagleman's theory seems to explain a dozen or so similar illusions. Yet it can't rule out the possibility that in certain situations, some internal clock in the brain might really

�f you speed u p someone� s u bjective time, they rea lly do seem to be able to p rocess more i nformation" tick at a faster or slower rate, changing the perceived speed of events in the process. Take the peculiar case of an individual known as BW. As BW drove his car one day, the trees and buildings by the road began to speed by, as if he were driving at 300 kilometres per hour. BW eased up on the accelerator, but the cityscape continued to whizz by. Unable to cope with the speed of the world around him, BW stopped his car by the roadside. While BW perceived the world as having accelerated, in reality what had happened was that BW had slowed down. He walked and talked in slow motion: when his doctor asked him to count 60 seconds in his head, he took 280 seconds to do it. It turned out that he had a tumour in his brain's frontal cortex. The case is not unique. Other people with damage in that area have reported similar > 24 October 2009 1 NewScientist 1 35


symptoms. Though such drastically altered perception can clearly be debilitating, it might occasionally be advantageous to change the brain's internal clock. "Accelerating" the brain - the opposite of BW's experience - might help a footballer, say, or a soldier to view the world in slow motion when things get tight. The difficulty, however, is in finding a safe way to induce the phenomenon on demand.

Speeding up the brain John Weardon, a n experimental psychologist at Keele University in the UK, claims to have found a way. When Weardon exposed his subjects to 10 seconds of fast clicks (about 5 per second) and then asked them to estimate the duration of a burst of light or a sound, they believed that second stimulus lasted about 10 per cent longer than if they'd heard silence or white noise before the burst. It looked as though their central pacemaker had accelerated but, again, the results might simply have been due to a distortion of memory. So Weardon's former student, Luke Jones at the University of Manchester, UK, decided to test the subjects' rate of mental processing during the experience. After exposing them to the clicks, he measured how quickly they could accomplish three different tasks : basic arithmetic, memorising words or hitting a specific key on a computer keyboard. The results, to be published in the Quarterly Journal ofExperimental Psychology, showed that the clicks accelerated the subjects' performance

Delusions on demand Schizophrenia has many symptoms:

accurately than most others. Now

brains compensated forthe delay,

tormenting voices which emanate

a flurry of studies has shown that if

to the extent that they actually

demonstrate that these eerie feelings

It's not the only experiment to

from windows or walls; delusions in

you upset the internal clocks of

perceived the movement of the

can arise from a faulty understanding

which those affected lose the

healthy people, you can create some

mouse and the movement of the

of the timing of events. For example,

sensation of controlling their own

of the symptoms and delusions

aircraft to take place simultaneously.

bodies and thoughts; and occasional

associated with schizophrenia.

But the subjects' strangest

we cannot normally tickle ourselves; somehow the intention to make the

clumsiness or a jerky gait. (ould all

In one experiment, healthy

experience occurred then the

movement also suppresses the

these problems stem from a faulty

volunteers learned to play a video

experimenters removed the delay

response. But when people were

internal clock?

game in which they had to steer

and set the timing back to normal.

asked to brush the palm of their hand

a plane around obstacles. Once

Suddenly, the players were perceiving

using a robotic probe that introduced

to affect people's perception of time.

people became used to the game,

the plane to be moving before they

a 200-millisecond delay between the

If someone with schizophrenia is

the researchers modified it to insert

consciously steered it with the mouse

intended movements and the actual

Schizophrenia certainly seems

shown a flash of light and a sound

a O.2-second delay in the plane's

(Psychological Science, vo1 12, p 532).

movements, they felt the same

separated by l/l Oth of a second, they

response to volunteers moving the

That's uncannily similar to how people

sensation as they would if someone

typically have trouble discerning

computer mouse. After the

with schizophrenia describe feelings

else were tickling them.

which came first. Such people also

modification, the players' performance

that they are somehow being

estimate the passing of time less

initially worsened; but in time their

controlled by another being.

36 1 NewScientist 1 24 October 2009

"That gets to a core issue in schizophrenia -the question of


in all three tasks by 10 to 20 per cent. It was N o ca me ra req u i red as if the drumbeat oftheir brain's internal slave In a movie this wheel would appear to be m ovi ng anticlockwise, when i n fact it is ro l l i n g cl ockwise galley had sped up - compelling each neuron to row faster. White noise had no such effect. Each frame captured by the camera shows The i l l usion, often seen in o l d weste rns "Information processing in the brain is running can be created in real l ife too, with no the wheel after just under a quarter of a in subjective time," says Weardon. "If you speed camera present. suggesting that the brain revo l ution. The bra i n assumes the wheel has creates the perception of continu ity from a moved the smaller distance - a slight angle up people's subjective time, they really do seem anticl ockwise with each frame, rather than series of di screte frames, just l i ke a fil m reel to have more time to process things." the bigger rotation c l ockwise A 10 per cent improvement could make all the difference in plenty of real-world situations. By listening to click trains through headphones, cricket or baseball batters might improve their reaction times and scores. "It would be instantly banned by sporting authorities," Weardon reckons, but this sort of neural enhancement would be welcome in other quarters - allowing students to cram more work into less time, for example. waves too - perhaps those that correspond "It's a cool result," says Eagleman - but he their observations arise from simple arousal. to the discrete snapshots in our perceptions. wonders whether click trains may simply "perk For one thing, white noise had no impact on VanRullen and Iones agree that this may be the person up a bit, like a little shot of caffeine," their subjects' performance in mathematics or memory tests, nor on their time perception. the answer. "When you have faster rather than having anything to do with time. Nor did the subjects show changes in heart oscillations, you have more snapshots per If that is the case, it may be little more than a close relative of the "Mozart effect". In 1993, second," says VanRullen. "You may be more rate, skin conductance or muscle tension researchers observed that students' associated with excitation. "We don't get any efficient at particular cognitive tasks, and because there are more snapshots in a given performances improved if they listened to increase in autonomic arousal," says Iones. So how else might the click trains alter time time, it may seem to last for longer." classical music before taking a test, but later If this theory is correct, the click train is perception and information processing studies showed that many sounds, including traffic noise or speech, can provide the same speeds? Edward Large, a neuroscientist at literally resetting the brain's frame-capture benefit. "It seems that any external auditory rate. It's an intriguing possibility. Who hasn't Florida Atlantic University at Boca Raton, has wished for a little more time now and then? found that rhythmic sounds can entrain stimulus has this excitatory, or arousal gamma brain waves, causing the beginning effect," says Edward Roth, who teaches music And you won't need to fall from an 8-story therapy at Western Michigan University in tower to get it. • of each sound to be accompanied by a burst Kalamazoo and has studied the Mozart effect. of several especially strong wave peaks. The click train may entrain other types of brain Weardon and Iones, however, doubt that Douglas Fox is a writer based in San Francisco

whether you are in control of your

feel as if someone else is controlling

brain: the cerebellum. For decades,

own body," says William Hetrick, who

your movements. And when an

the cerebellum has been seen as a

Texas, has studied people with

studies the brain's timekeeping and

advert appears on TV, your brain

centre for timing the movement of

schizophrenia using a video game

schizophrenia at Indiana University in

might picture the product before it

muscles, but some neuroscientists

similar to the aircraft game, which

Bloomington. "The ability to attribute

consciously registers seeing it on

now reckon that it might coordinate

lets him manipulate delays between

actions to oneself versus others, to

screen -creating the disturbing

thoughts and the processing of

volunteers' actions and

sensory perceptions too.

their outcomes.

perceive one's own thoughts against thoughts generated from external sources, perhaps requires a tight coupling in time [within the brain]." The idea could explain many of the experiences reported by people with

"By upsetting the brai n's clock, you can recreate some of the del usions seen in schizophren ia"

That would fit with the

College of Medicine in Houston,

When he alters time delays, people

neurological evidence. "During a

with schizophrenia find it more

broad range of mental tasks, people

difficult to compensate than healthy

with schizophrenia have lower rates

controls. "Schizophrenic brains seem

of cerebellar blood flow than healthy

to be temporally inflexible;' he says.

schizophrenia. By muddling the order

illusion that your thoughts are being

people do," says Nancy Andreasen,

"They don't recalibrate." Eagleman

of thoughts and perceptions within

broadcast on television.

a schizophrenia researcher at the

hopes such games might be useful in

your brain, for example, you might

If poor time-processing really does

move your hand before you are

underlie many psychotic delusions, it

conscious of the decision, making it

could point to a single culprit in the

University of Iowa in Iowa City. The idea has sparked plenty of interest. David Eagleman at Baylor

the future to measure the severity of schizophrenia, or patients' responses to treatment and drugs.

24 October 2009 1 NewScientist 1 37


Sunshine su perpower I s b u i l d i n g a g i g a ntic e l ectri city p l a nt i n the Sa h a ra rea l ly such a good i d ea, a s ks Fred Pea rce

E

VERY two weeks, the sun pours more energy onto the surface of our planet than we use from all sources in an entire year. It is an inexhaustible powerhouse that has remained largely untapped for human energy needs. That may soon change in a big way. If a consortium of German companies has its way, construction ofthe biggest solar project ever devised could soon begin in the Sahara desert. When completed, it would harvest energy from the sun shining over Africa and transform it into clean, green electricity for delivery to European homes and businesses. Prospects for the project, called Desertec, have blossomed over the past year, and this month 20 major German corporations are expected to announce the formation of a consortium that will provide the €400 billion needed to build a raft of solar thermal power plants in north Africa. They include energy utilities giants E.ON and RWE, the engineering firm Siemens, the finance house Deutsche Bank and the insurance company Munich Re. The current plan, outlined by the German Aerospace Centre (DLR) in a report to the federal government, envisages that the project will meet 15 per cent of Europe's electricity needs by 2050, with a peak output of 100 gigawatts - roughly equivalent to 100 coal-fired power stations. Preliminary designs in the German report show electricity reaching Europe via 20 high-voltage direct­ current power lines, which will keep transmission losses below 10 per cent (New Scientist, 14 March, p 42). Trans-Mediterranean links will cross from Morocco to Spain across the Strait of Gibraltar; from Algeria to France via the Balearic islands; from Tunisia to Italy; from Libya to Greece; and from Egypt to Turkey via Cyprus. Desertec would take its place in a wider European supergrid that conveys power generated from wind turbines in the North 38 1 NewScientist 1 24 Octo ber 2009

Sea, hydroelectric dams in Scandinavia, hot rocks in Iceland and biofuels in eastern Europe. Adding solar thermal capacity would help ensure a steady supply of green electricity. But is this really the best use of such a colossal amount of money? Critics are lining up to point out the project's shortcomings. They say it could make Europe's energy supply a hostage to politically unstable countries; that Europe should not be exploiting Africa in this way; that it is a poor investment compared to covering Europe's roofs with photovoltaic (PV) solar panels; and that, while deserts have plenty of sun, they lack another less obvious but equally indispensable resource for a solar thermal power plant - water. Is Desertec really the model of future power generation, as its promoters would have us believe, or is it politically misconceived and a monumental waste of money?

Canned heat Unlike PV panels, which convert sunlight directly into electricity, solar thermal electricity generation plants first trap solar energy in the form of heat, and use this heat to generate electricity just as a conventional power plant does. Solar thermal plants come in four main varieties. Three use mirrors that concentrate sunlight to heat oil, water or a molten salt, which is in turn used to generate steam that drives a turbine. The mirrors can take the form of parabolic troughs or an array of flat reflectors that redirect sunlight onto pipes suspended above them, heating the fluid that they contain. In the Mojave desert in California, an interlinked system of nine solar thermal plants which use trough mirrors has been generating up to 300 megawatts of electrical power for more than two decades. Alternatively, a field of mirrors can focus sunlight onto a central ceramic heat absorber

mounted on a tower. A prototype plant in Spain has 21,000 square metres of glass mirrors that heat the absorber to over 1000 °C and generate 1 megawatt. In the fourth type, a dish focuses heat on a Stirling engine which generates electricity by exploiting the expansion and contraction of a gas in a sealed piston chamber as it is heated and then allowed to cool (see diagrams, pages 40 and 41). Solar thermal energy is now coming to the fore, as it proves itself to have several advantages over PV. Among these is its ability to produce electricity in power-station quantities, without the complex organisation that distributed generation entails. What's more, it can feed electricity into the grid at night as well as by day. This is done by storing the heated fluid in an insulated container and releasing it hours later when the energy is required. Storing energy from PV panels would require a new generation of high­ capacity batteries - still a research project in its infancy for the scale needed. The clincher


is cost. Building a power-station-scale solar thermal installation costs only a fraction of PV generators with the same output. As a result, an army of new solar thermal plants are being planned for the US, China, Australia and Israel. PV cells have one clear advantage, however. Solar thermal requires direct sunlight, and so a cloudy day will slash power output to near

today and that all of Europe's electricity could be made in an area 250 kilometres across. In December, world leaders are likely to agree in Copenhagen, Denmark, on the need to cut carbon dioxide emissions by up to 80 per cent by 2050, so technologies to deliver these cuts are needed. Until recently, PV panels had been seen as the favourite route to

lilt is c l a i med that the p roj ect co u l d meet 15 per ce nt of E u ro p e's e l ectri c ity n e e d s by 205011 zero, whereas PV cells will generate at least some power until night descends. But the intensity of sunshine blasting the Sahara desert more than compensates for this. Every year, each square metre of the Sahara receives more heat from the sun than would be obtained by burning two barrels of oil. Desertec reckons that a patch less than 600 kilometres across could meet the entire world's electricity needs

emissions-free electricity. They are modular, compact and generate electricity even on a cloudy day. Because the panels are costly, supporters of PV have advocated putting panels on roofs, and generating electricity that will make the buildings concerned self足 sufficient - and with luck provide some extra that can be fed back into the grid. Out in the Sahara, however, another

problem has to be solved. Like a regular coal or oil-fired plant, a solar thermal generating station requires large amounts of cooling water to condense the steam after it goes through the generator's turbines, and there are inevitable losses from evaporation. The solar trough plant in the Mojave desert consumes around 3000 litres of water for every megawatt-hour of electricity it produces, and others are likely to need similar amounts. That's a lot of water to find in a desert. A typical Saharan solar farm would be expected to deliver abount 120,000 megawatt -hours of electricity per year per square kilometre. That equates to some 350 million litres of water, or enough to flood its area to a depth of 35 centimetres - not much less than would be needed to irrigate a crop of wheat. There is water beneath the Sahara. The giant Nubian aquifer is probably the world's largest, containing an estimated 60,000 cubic kilometres ofwater. But this is a non-renewable resource : it is a deep fossil reserve that has > 24 October 2009 1 NewScientist 1 39


been there for thousands of years and will not running costs. David Mills, whose company reserves by 35 trillion litres a year. By 2050, be replenished by rains. Moreover, the expense Ausra in Palo Alto, California, wants to build Desertec's solar thermal plants could almost and effort required to tap it are huge. Libya has an air-cooled solar thermal plant in the Nevada double the region's supply of fresh water. Whatever part desalination plays, it will not spent $27 billion ofits oil revenues over the past desert, says air cooling involves about a 10 per two decades building a system to deliver this be feasible to build solar thermal plants close cent penalty in terms of cost or performance. water to coastal farms for irrigation. The to the sea, as clouds lurk there. Maps in the The DLR's report does not directly address country pumps about 2 cubic kilometres Desertec's potential water requirements. German report show that along much of the Instead, it focuses on the fresh water the plants Atlantic and Mediterranean coastlines of (2 trillion litres) of water a year to the surface could produce by using part of their output to north Africa, solar radiation levels are below and sends it down a network consisting of desalinate seawater - a factor that Desertec's the threshold of commercial viability, which 3500-kilometres of massive 4-metre pipes that make up the so-called Great Man-made River. Costs on anything like that scale would "E u ro p e co u l d g e n e rate a l l the d o m esti c e n e rgy it make Desertec uneconomic. In a study for the US Congress, the needs th ro u g h roof to p p h otovo lta i c so l a r p a n e l s" Department of Energy concluded in February this year that water is shaping up to be a major constraint on harnessing solar power in desert backers hope will persuade north African the report's authors have set at 2 megawatt­ areas. The US National Park Service agrees. In hours per year from every square metre. governments to allow their land to be used to Some of the opposition to Desertec generate electricity for export. Let us use your April, it warned that solar thermal projects proposed for the Mojave desert could destroy sun to generate power, the argument goes, and comes from an unexpected quarter. Hermann you can share some of that energy to desalinate Scheer, the German member of parliament its limited underground water reserves. seawater to irrigate crops that will help feed who masterminded the programme that has Switching to air cooling for thermal solar power stations would cut water demand by up your growing populations. The German report put solar panels on 100,000 of the country's to go per cent, but brings problems of its own. estimates that north Africa's demand for water roofs, declared Desertec to be an unnecessary and expensive distraction that would divert Air cooling is less efficient than water cooling, will increase by two-thirds in the coming so the installations would require more land investment from projects in Germany itself. 40 years - far beyond available supply. The region is already over-pumping underground Europe could generate as much solar energy and more mirrors, adding to the capital and

Catch i n g the s u n

There are four ma i n ways of using heat from the sun to generate e lectricity

S o l a r towe r Pros

Pros

Locks on and tracks the s u n

H i g h operat i n g temperature

Very h i g h temperature ( N 790°C)

(565°C)

High efficiency of conversion

Heat stora ge built i nto design

of heat to e l ectricity ( N 30%)

Large·scale p l a nts produce

Can b e i n sta l l e d o n u n even

cheaper power than other options

g r o u n d . Further u n its can be

(ons

i n sta l l e d w h e n needed

H i g h water req u i rement

Low water re q u i rement m i rror

i n re c i rculating design

c l e a n i n g o n l y ( N 80 Iitres/M Wh)

(2000-300 0 I itres/MWh)

(ons No commercial i n sta l l ations yet;

Sti rling engine prod uces electricity d i rectly from heat without generating steam

two p l a n ned for Los Angeles C a n n ot easily store heat C a n n ot g e n e rate when s u n

Small p l a nts very expensive

S u n -tracking mi rrors focus its rays on wi ndow i n tower

M o lten salt pi ped past w i n d ow is heated to 565°C

is not shining

_",=,Ir---jc=",,"" WASTE H EAT

Sunl ight heats t h e chamber, causing the gas inside to expand This pushes piston A inwards, rotati n g the crankshaft As the shaft rotates, piston B draws warm gas into the upper chamber where it cools

PI STO N A L---"-.,..-

40 1 N ewScientist 1 24 October 2009

SHAFT DRIVES

On the return stroke, piston A returns gas to the chamber where it is heated to begin the next cycle

HOT SALT \

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...---""'L.....r-.----;,. Ar-+--'" C O O L SALT RETURNED FOR H EATI N G

I

STEAM TURBINE

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as it needs domestically with more rooftop PV panels, Scheer says. "It is strange how even Greenpeace has not yet understood this," he adds. "By the time solar power from north Africa can be supplied for the prices Desertec has promised, solar power generation will happen at a noticeably lower price here at home." Desertec supporters argue that the two types of system complement each other. In particular, stored heat at solar thermal plants can deliver electricity through the night, when output from Europe's photovoltaic panels dies. If the argument comes down to cost, how do the numbers stack up? In terms of capital cost, large-scale solar thermal installations are the clear winner. Building the plant now operating in Spain has cost €1670 for each megawatt­ hour of electricity it produces each year. Jeremy Leggett, who heads Solar Century, a London-based company which sells PV technology, says that installing PV panels would eat up more than double that, at €4000 per megawatt-hour per year. But capital cost is not the end of the story. While a solar thermal power plant requires a round-the-clock crew, PV installations pretty much run themselves.

What's more, PV power plants can grow electricity for Europe. Desertec says that two­ thirds of the potential solar resource in north piecemeal: they can start generating power Africa and the Middle East lies in Algeria, Libya for the grid from the day the first panel is and Saudi Arabia. Europe, like the US, wants to installed, while solar thermal mirrors are reduce its reliance on energy imported from useless until the entire power station is completed. For Desertec, there is also the small distant lands with an unpredictable political matter of getting Desertec's electricity from future. Why create a new hostage to fortune? Africa to Europe. With this many variables in The stage is set to recreate an uncomfortable the equation it becomes hard to make realistic parallel with western dependency on oil from Saudi Arabia, Iran and Iraq. comparisons between the available options. Ifeanyi Amajuoyi, who runs the Nigerian To fill the gap, Anthony Patt of the renewable energy company Nkubadorf, has International Institute for Applied Systems Analysis, a think tank in Laxenburg, Austria, is set up an organisation called Desertec-Africa conducting a detailed feasibility study of solar to promote the cause of exploiting African sunshine for the benefit of Africans. He plans to thermal power generation. He reckons that begin campaigning for governments in Africa to Desertec is unlikely to be competitive with ensure the energy from Desertec stays in Africa. coal-fired power generation for at least two decades, during which time it will swallow While the technical and political hurdles between €20 and €so billion, similar in scale facing Desertec are considerable, the rewards to Germany's expected subsidy for PV cells if it succeeds could be huge. It will elevate over the same period. renewables into one of the dominant energy And then there are the tricky political issues providers for Europe, and help make fossil that arise from a plan that will exploit land fuels a thing of the past. If it fails, the red faces won't be from desert sunburn . • in Africa, and possibly Asia too, to generate Fred Pearce is New Scientist's senior environment correspondent

Area of solar thermal power c o l l ectors that Desertec says is needed to g e n e rate e l ectricity for

• World 2005 D European U n i o n 2005

S o l a r tro u h

L i n e a r f res n e l refl ecto rs Pros

Pros

Most developed tec h n o l o gy, with

M i rrors easy to c l e a n

commercial p l a nts that have run

Cheap option

for ove r a decade

Tight arrangement means

Can use thermal stora g e for

effici ent use of l a n d

g e n e ration when sun is not

Could b e made t o store heat

shining

if molten salt replaced water

Can be combined w i t h g a s b u r n e r for back-up

Cons Water is heated i n pressurised tubes to produce steam at 2800( and 50 atmospheres

Cons

Low optical efficiency

Low m a x i m u m operating

of m i rrors means poor e n e rgy efficiency No commercial versions so far Existing d e s i g n s c a n n ot

temp erature means not very space efficient

Parabolic trough m i rrors track s u n and focus rays on pipes ca rryi n g o i l

H i g h water req u i rement (3000 l itres/MWh)

store heat High water req u i rement

COOL O I L

( N 4000 l itres/MWh)

STEAM

PA RABOLIC

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24 October 2009 1 NewScientist 1 41


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ust1 ce you ca n cou nt o n A poor g rasp of mathematics may be co m p ro m i s i n g our leg a l systeml wa rns Angela Sai n i

S

HAMBLING sleuth Columbo always gets his man. Take the society photographer in a 1974 episode of the cult US television series who has killed his wife and disguised it as a bungled kidnapping. It is the perfect crime - until the hangdog detective hits on a cunning ruse to expose it. He induces the murderer to grab from a shelf of 12 cameras the exact one used to snap the victim before she was killed. "You just incriminated yourself, sir," says a watching police officer. If only it were that simple. Killer or not, anyone would have a 1 in 12 chance of picking the same camera at random. That kind of evidence would never stand up in court. Or would it? In fact, such probabilistic pitfalls are not limited to crime fiction. "Statistical errors happen astonishingly often," says Ray Hill, a mathematician at the University of Salford, UK, who has given evidence in several high-profile criminal cases. ''I'm always finding examples that go unnoticed in evidence statements." The root cause is a sloppiness in analysing odds that can sully justice and even land innocent people in jail. With ever more trials resting on the " certainties" of data such as DNA matches, the problem is becoming more acute. Some mathematicians are calling for the courts to take a crash course in the true significance of the evidence put before them. Their demand: Bayesian justice for all. That rallying call derives from the work of Thomas Bayes, an 18th-century British mathematician who showed how to calculate conditional probability - the chance of something being true if its truth depends on

other things being true, too. That is precisely the kind of problem that criminal trials deal with as they sift through evidence to establish a defendant's innocence or guilt (see "Bayes on trial", below). Mathematics might seem a logical fit for the courts, then. Judges and juries, though, all too often rely on gut feeling. A startling example was the rape trial in 1996 of a British man, Dennis John Adams. Adams hadn't been

identified in a line-up and his girlfriend had provided an alibi. But his DNA was a 1 in 200 million match to semen from the crime scene - evidence seemingly so damning that any jury would be likely to convict him. But what did that figure actually mean? Not, as courts and the press often assume, that there was only a 1 in 200 million chance that the semen belonged to someone other than Adams, making his innocence implausible. >

8ayes on trial Suppose you have a piece of evidence, E, from a crime scene -a bloodstain, or perhaps

they are innocent: PIE 1 H) 0.1. To apply

Bayes's formula and find P(H 1 E) -your new =

a clothing thread - that matches to a suspect.

estimation of the defendant's innocence 足

How should it affect your perception or

you now need the quantity P(E) , the

hypothesis, H, of the suspect's innocence?

probability that his blood matches that at the

Bayes's theorem tells you how to work out the probability of H given E. It is: (the

crime scene. This probability actually depends on the

probability of H) multiplied by (the probability

defendant's innocence or guilt. If he is

of E given H) divided by (the probability of E).

innocent. it is 0.1 as it is for anyone else. If he is

Or in standard mathematical notation:

guilty, however, it is 1, as his blood is certain to

P(H 1 E)

=

P(H)

x

PIE 1 H)/ PIE)

Say you are a juror at an assault trial, and so far you are 60 per cent convinced the defendant is innocent: P(H) 0.6. Then =

you're told that the blood of the defendant

match. This insight allows us to calculate PIE) by summing the probabilities of a blood match in the case of innocence (H) or guilt (not H): PIE)

=

=

[PIE 1 H)

(0.1

x

x

P(H)] + [PIE 1 not H) x P(not H)]

0.6) + (1

x

0.4)

=

0.46

and blood found at the crime scene are both

So according to Bayes's formula the revised

type B, which is found in about 10 per cent of

probability of his innocence is:

people. How should this change your view? What the forensics expert has given you is

P (H 1 E) (0 . 6 x 0 . 1)';'0.46 0.13 As you might expect, by this measure the =

=

the probability that the evidence matches

defendant is between four and five times

anyone in the general population, given that

guiltier than you first thought - probably.

24 October 2009 1 NewScientist 1 43


FIVE FALLACI ES TO FORGO

It actually means there is a 1 in 200 million has just come up with a possible solution. With his colleague Martin Neil, he has chance that the DNA of any random member of the public will match that found at the developed a system of step-by-step pictures and decision trees to help jurors grasp crime scene (see "The prosecutor's fallacy", right). The difference is subtle, but significant. Bayesian reasoning (bit.ly/lc3tgil. Once a jury In a population, say, of 10,000 men who could has been convinced that the method works, I t pays to b e careful when the duo argue, experts should be allowed to have committed the crime, there would be a apply Bayes's theorem to the facts of the case 10,000 in 200 million, or 1 in 20,000, chance using statistics as evidence, as a kind of "black box" that calculates how the that someone else is a match too. That still as these examp les from the probability of innocence or guilt changes as doesn't look good for Adams, but it's not legal casebook show nearly as damning. each piece of evidence is presented. "You wouldn't question the steps of an electronic So worried was Adams's defence team that the jury might misinterpret the odds that they calculator, so why here?" Fenton asks. 1. PROSECUTOR'S FALLACY called in Peter Donnelly, a statistical scientist It is a controversial suggestion. Taken to its logical conclusion, it might see the outcome of "The prosecutors fallacy is such an easy mistake to at the University of Oxford. "We designed a a trial balance on a single calculation. Working make," says lan Evett from the Forensic Science questionnaire to help them combine all the evidence using Bayesian reasoning," says Service in England and Wales. It confuses two subtly out Bayesian probabilities with DNA and blood matches is all very well, but quantifying different probabilities that 8ayes's formula Donnelly (Significance, vol 2, p 46). They failed, though, to convince the jury incriminating factors such as appearance and distinguishes: P(H 1 E), the probability that someone of the value of the Bayesian approach, and is innocent if they are a match to a piece of behaviour is more difficult. "Different jurors Adams was convicted. He appealed twice will interpret different bits of evidence evidence, and P(E 1 H), the probability that someone unsuccessfully, with an appeal judge differently. It's not the job of a mathematician is a match to a piece of evidence if they are innocent to do it for them," says Donnelly. eventually ruling that the jury's job was (see "8ayes on trial", previous page). The first He thinks forensics experts should be "to evaluate evidence not by means of a probability is what we would like to know; the formula . . . but by the joint application of schooled in statistics so they can catch errors second is what forensics usually tells us. before they occur. Since cases such as Adams's, their individual common sense." Unfortunately, even professionals sometimes mix them up. In the 1991 rape trial of Andrew Deen that has already begun to happen in the US But what if common sense runs counter to justice ? For David Lucy, a mathematician at and UK. Lawyers and jurors, however, still in Manchester, UK, for example, an expert witness have far less - if any - statistical training. Lancaster University in the UK, the Adams agreed on the basis of a DNA sample that "the judgment indicates a cultural tradition that As the real-life fallacies that follow show, likelihood of [the source of the semen] being any other man but Andrew Deen [is] 1 in 3 million." there's no room for complacency. It is not needs changing. "In some cases, statistical analysis is the only way to evaluate evidence, about mathematicians trying to force their That was wrong. One in 3 million was the because intuition can lead to outcomes based likelihood that any innocent person in the general way of thinking on the world, says Donnelly: "Justice depends on getting everyone to population had a DNA profile matching that upon fallacies," he says. Norman Fenton, a computer scientist at reason properly with uncertainties." • extracted from semen at the crime scene -in other Queen Mary, University of London, who has words, P(E 1 H). With around 60 million people in the worked for defence teams in criminal trials, Angela Saini is a writer based in London UK, a fair few people will share that profile. 44 1 N ewScientist 1 24 Octo ber 2009


Depending on how many of them might plausibly

ex-wife, Nicole Brown, and her friend. Years before,

have committed the crime, the probability of Deen

Do n't pa n i c

Simpson had pleaded no contest to a charge of

being innocent even though he was a match, or

You've just been diagn osed with a rare condition that

domestic violence against Brown. In an attempt to

P(H 1 E}, was actually far greater that 1 in 3 million. Deen's conviction was quashed on appeal.

leading to a flurry of similar appeals that have

affl icts 1 i n 10,000. The test is 99 per cent certa i n. H o pe or despair?

•

True positive

down play that, a consultant to Simpson's defence team, Alan Dershowitz, stated that fewer than 1 in

•

1000 women who are abused by their husbands or

False positive

had varying success. The latest is the appeal of a

I n a p o p u l ation of 10,000, o n average one person w i l l

Californian man jailed last year, who was discovered

have t h e d i sease - a n d they w i l l a l s o test positive

boyfriends end up murdered by them. That might well be true, but it was not the most relevant fact, as John Alien Paulos, a mathematician

by police to be a DNA match to a rape and murder committed 35 years earlier.

at Temple University in Philadelphia, Pennsylvania, later showed. As a Bayesian calculation taking in all the pertinent facts reveals, it is trumped by the 80

2. U LT I M ATE I SS U E E RRO R

per cent likelihood that, if a woman is abused and later murdered, the culprit was her partner.

The prosecution in the Deen case stopped just

That may not be the whole story either, says

short of compounding their probabilistic fallacy.

criminologist William Thompson of the University of

In the minds of the jury, though, it probably morphed into the "ultimate issue" error: explicitly

California, Irvine. lf more than 80 per cent of all

equating the (small) number P(E 1 H} with a suspect's

murdered women, abused or not, are killed by their partner, "the presence of abuse may have no

likelihood of innocence.

diagnostic value at all".

In Los Angeles in 1968, the ultimate issue error sent Malcolm Collins and his wife Janet to jail. At first glance, the circumstances of the case left little room for doubt: an elderly lady had been robbed by a

If the test is o n l y 99 per cent accurate,

1 per cent of the

re m a i n i ng, hea lthy p o p u lation will test positive too

5. D E P E N D E NT EV I D E N C E FALLACY

white woman with blonde hair and a black man with

Sometimes, mathematical logic flies out of the

a moustache, who had both fled in a yellow car. The

courtroom window long before Bayes can even be

chances of finding a similar interracial couple

applied - because the probabilities used are wrong,

matching that description were 1 in 12 million,

Take the dependent evidence fallacy, which was central to one of the most notorious recent

an expert calculated.

miscarriages of justice in the UK. ln November 1999,

The police were convinced, and without much deliberation so was the jury. They assumed that

Sally Clark was convicted of smothering her two

there was a 1 in 12 million chance that the couple

children as they slept. A paediatrician, Roy Meadow,

were not the match, and that this was also the

testified that the odds of both dying naturally by sudden infant death syndrome (SIDS), or cot death,

likelihood of their innocence.

were 1 in 73 million. He arrived at this figure by

They were wrong on both counts. In a city such

multiplying the individual probability of SIDS in a

as Los Angeles, with millions of people of all races living in it or passing through, there could well be at

So i f you test positive, all oth e r th i ngs be i n g equal,

least one other such couple, giving the Collinses an

the re's a chance of over 99 per cent you

evens or better chance of being innocent. Not to

the d i sease

-

HOPE

don't have

family such as Clark's - 1 in 8500 - by itself. as if the two deaths were independent events. But why should they be? "There may well be

mention that the description itself may have been

unknown genetic or environmental factors that

inaccurate - facts that helped reverse the guilty

predispose families to SIDS, so that a second case within the family becomes much more likely," the

verdict on appeal. It is in fact less than 1 per cent. The reason is the

3 . BAS E - RATE N EG LECT

sheer rarity of the disease, which means that even

Royal Statistical Society explained during an appeal. "Even three eminent judges didn't pick up on the

with a 9 9 per cent accurate test, false positives will

mistake," says Ray Hill of the University of Salford,

Anyone looking to DNA profiling for a quick route to

far outweigh real ones (see diagram, above). That's

who worked for the defence team. He estimated

a conviction should recognise that genetic evidence

why it is so important to carry out further tests to

that if one sibling dies of SIDS, the chance of another

can be shaky. Even if the odds of finding another

narrow down the odds, We lay people are not the

dying is as high as 1 in 60, Bayesian reasoning then

genetic match are 1 in a billion, in a world of 7 billion,

only ones stumped by such counter-intuitive

produces a probability of a double cot death of

that's another seven people with the same profile. Fortunately, circumstantial and forensic evidence often quickly whittle down the pool of suspects. But

results: surveys show that 85 to 90 per cent of

around 1 in 130,000. With hundreds of thousands

health professionals get it wrong too (Behaviora/

of children born each year in the UK, there's bound

ond Brain Sciences, vo1 30, p 241).

to be a double cot death every now and then.

4. D E F E N DAN T'S FALLACY

Her case had a lasting effect, leading to the review

Clark was eventually freed on appeal in 2003.

neglecting your "base rate" -the pool of possible matches -can have you leap to false conclusions, not just in the courtroom. Picture yourself. for example, in the doctor's

It's not just prosecutors who can fiddle courtroom

of many similar cases. "I'm not aware of any cases of multiple cot deaths reaching the courts in recent

surgery. You have just tested positive for a terminal

statistics to their advantage: defence lawyers have

years;' says Hill. Clark herself never recovered from

disease that afflicts 1 in 10,000. The test has an

also been known to cherry-pick probabilities.

her ordeal. however. She was found dead at her

accuracy of 99 per cent. What's the probability that you actually have the disease?

In 1995, for example, former American football star O.J. Simpson stood trial for the murder of his

home in 2007, ultimately a victim of statistical ignorance. Angela Saini 24 October 2009 1 NewScientist 1 45


� � ...... �

If yo u\7e neve r co n s i d e red the eco l o g i c a l pawpri nt o f yo u r fu rry fri end, it's t i m e to fa ce tb'le fa cts, says Kate Ravi l i ous

� ..,.., � �

{Mqyv green �(� your pet7. •

......

,.., "'"

""' ,.., � � '"' � 'P"I ""i "'1"\ .,., '" '" '" .,., ,.., �

S

HOULD owning a great dane make you as much of an eco-outcast as an SUV driver? Yes it should, say Robert and Brenda Vale, two architects who specialise in sustainable living at Victoria University of Wellington in New Zealand. In their new book, Time to Eat the Dog: The real guide to sustainable living, they compare the ecological footprints of a menagerie of popular pets with those of various other lifestyle choices - and the critters do not fare well. As well as guzzling resources, cats and dogs devastate wildlife populations, spread disease and add to pollution. It is time to take eco­ stock of our pets. To measure the ecological paw, claw and fin-prints of the family pet, the Vales analysed the ingredients of common brands of pet food. They calculated, for example, that a medium-sized dog would consume 90 grams of meat and 156 grams of cereals daily in its recommended 300-gram portion of dried dog food. At its pre-dried weight, that equates to 450 grams of fresh meat and 260 grams of cereal. That means that over the course of a year, Fido wolfs down about 164 kilograms of meat and 95 kilograms of cereals. It takes 43.3 square metres of land to generate 1 kilogram of chicken per year far more for beef and lamb - and 13.4 square metres to generate a kilogram of cereals. So that gives him a footprint of 0.84 hectares. For a big dog such as a German shepherd, the figure is 1.1 hectares. Meanwhile, an SUV - the Vales used a 4.6-litre Toyota Land Cruiser in their comparison - driven a modest 10,000 46 1 NewScientist 1 24 Octo ber 2009

kilometres a year, uses 55.1 gigajoules, which includes the energy required both to fuel and to build it. One hectare of land can produce approximately 135 gigajoules of energy per year, so the Land Cruiser's eco-footprint is about 0-41 hectares - less than half that of a medium-sized dog. The Vales are not alone in reaching this conclusion. When New Scientist asked John Barrett at the Stockholm Environment Institute in York, UK, to calculate eco­ pawprints based on his own data, his figures tallied almost exactly. "Owning a dog really is quite an extravagance, mainly because of the carbon footprint of meat," he says.

Eco-pawprints Then there are all the other animals we own. Doing similar calculations for a variety of pets and their foods, the Vales found that cats have an eco-footprint of about 0.15 hectares (slightly less than a Volkswagen Golf), hamsters come in at 0.014 hectares apiece (buy two, and you might as well have bought a plasma TV) and canaries half that. Even a goldfish requires 0.00034 hectares (3-4 square metres) of land to sustain it, giving it an ecological fin-print equal to two cellphones. This kind of analysis appeals to David Mackay, a physicist at the University of Cambridge and the UK government's new energy adviser. He believes we should put as much thought into choosing a pet as we do into buying a car. "If a lifestyle choice uses more than 1 per cent of your energy footprint, then it is worthwhile reflecting on


that choice and seeing what you can do about it," he says. "Pets definitely deserve attention: by my estimates, the energy footprint of a cat is about 2 per cent of the average British person's energy footprint - and it's bigger for most dogs." Alternatively, consider the cumulative environmental impact of our furry friends. The US, which tops the list for both cat and dog ownership in absolute terms, is home to over 76 million felines and 61 million canines. Taking the estimated cat population for the top 10 cat-owning countries, the Vales calculate that the land required just to feed these cats is over 400,000 square kilometres. That's equivalent to one-and-a-half times the area of New Zealand. A further five New Zealands are required to feed the pooches living in the top 10 dog-owning countries - which, perhaps surprisingly, does not include the UK. Then there are the other environmental impacts of pets. Every year, for example, the UK's 7.7 million cats kill over 188 million wild animals (Mammal Review, vol 33, p 174). That works out at about 25 birds, mammals and frogs per cat. Similar figures have emerged from surveys in the US and Australia. There is also a knock-on effect because cats feasting on wildlife can leave wild predators such as hawks and weasels short of food. Dogs are not entirely blameless either. In 2007, Peter Banks and jessica Bryant from the University of New South Wales in Sydney, Australia, monitored bird life in woodlands

La n d g u zz I e rs The ecological footpri nts of our pets can m a ke SUVs look positively eco-friendly

levels can starve waterways of oxygen and kill aquatic life. 7.7 m i l l i on cats ki l l over Cat excrement is particularly toxic. In 2002, it emerged that sea otters along the 188 m i l l ion wild a n imals. Californian coast are dying from a brain That's 25 per cat" disease caused by Toxoplasma gondii. The parasite, which is found in cat faeces, ends up just outside the city to assess the impact of in rivers and estuaries thanks to cat owners dogs being walked there (Biology Letters, who flush their cat litter down the toilet or vol 3, p 611). They showed that bird life in areas allow their cats to defecate outside. Dolphins frequented by dogs, even when kept on a lead, and whales are also affected (newscientist. com/article/dm4037) . had 35 per cent less diversity and 41 per cent fewer birds overall. Areas with off-lead dogs So what is an eco-friendly animal lover to do? If you already have a pet, then changing seem to suffer even more : ongoing studies in the UK indicate that dogs are aiding the its diet can help. Meat is the key, since its production is so energy-intensive. You can decline of some rare species of bird, such as almost halve the eco-pawprint of your dog European nightjars (Ibis, VOl 149, p 27). Another major environmental problem, simply by feeding it many of the same sort of particularly in urban areas, is pet faeces. savory foods that you eat, which are likely to A study carried out in Nashville, Tennessee, be far less protein-rich than most dog foods. indicated that it is a significant cause of high As well as quantity, think about quality. bacterial levels in local rivers and streams, "If pussy is scoffing 'Fancy Feast' - or some particularly after heavy rain. As well as making other food made from choice cuts of meat the water unsafe to drink, high bacterial then the relative impact is likely to be high,"

"Every yea r the U K's

says Robert Vale. "If, on the other hand, the cat is fed on fish heads and other leftovers from the fishmonger, the impact will be lower." Dog owners might also want to avoid walking their dog in wildlife-rich areas, and cat owners could consider keeping Tiddles indoors. "Cats are nocturnal, so the single most important thing people can do to reduce predation is to keep cats in at night," says Michael Woods of the Mammal Society in Southampton, UK. And if you are thinking of acquiring a pet? "Shared pets are the best - the theatre cat or the temple dogs," says Robert Vale. But if you must own your own, think about getting an animal that serves a dual purpose. He recommends hens, which partly compensate for their eco-footprint by providing eggs. Or there is an even better alternative, if you can stomach it. "Rabbits are good," he says, "provided you eat them." • Kate Ravil ious is a science journalist based in York, UK, and the gui lty owner of a medium-sized dog

24 October 2009 1 NewScientist 1 47


BOOKS & ARTS

To forget or not to forget. . . W i l l u s i n g tec h n o l ogy to reta i n every m e m o ry of o u r l ives p rove to be a b l essi n g o r a cu rse? bits of episodes is unlikely to authors, all you need are sensitive really revolutionary any more. We owe this lUXUry of habituation really preserve these episodes. miniature sensors and several revolution will change everything terabytes of storage, which are to the wonders of the electronic Furthermore, when we perceive by Gardan Bell and J i m Gemmell, already or soon-to-be affordable. the world, we get not only universe and to pioneers and Duttan, $26,95 You can then record every minute visionary entrepreneurs like Bell objective input but also the Delete: The virtue offorgetting of your life using video, audio, and Gemmell (and Gates). But in context, including our complex in the digital age by Viktor Mayer­ location and physiological signals, their self-confident manifesto, internal physiological milieu and Schiinberger, Princeton University these cyberspace explorers culminating in the commitment all of our emotional baggage. Press, $24,95/£16,95 of this endless stream of overlook some attributes of Again, it is unlikely that a Reviewed by Yadin Dudai information to your personal the cognitive universe. computerised total recall system JUST as Moliere's bourgeois MyLifeBits account in your pocket For example, as cognitive will be able to register this unique gentleman spoke in prose without and/or in cyberspace. Proper endogenous world and the way it interacts with the outside world to software will permit you to being aware of it, most of those "For the human condition, forgetting who fear forgetting do not realise retrieve the information years generate the subjective percept. is at least as important Most importantly, though, the that they have amnesiphobia. But later, and it will even pass by perhaps this tiny lexical blind as remembering" authors, consumed by their hunt default to your progeny for spot is not important any more. for every last bit of information eternity, with the hope that (and even offering practical advice psychology and neuroscience Amnesiphobics, unite and rejoice : they will pay attention to it. The information technology Gordon Bell and Jim Gemmell demonstrate again and again, on how to make an extra buck in (and Bill Gates, in his enthusiastic capabilities depicted in Total two individuals sensing the same the process), forget forgetting. introduction) now inform us that Recall are fascinating, yet not For the human condition, input, or the same individual we need never fear forgetting sensing the same input at different forgetting is at least as important again. Total recall is around the as remembering - sometimes times, may understand very Compulsively capturing memories corner. But alas, in such a world, more so. Without it, we are all different things. So registering may be missing the big picture even our phobia of forgetting cannot be forgotten. Even if we wished to forget, Bell and Gemmell say, we couldn't, as somewhere in the cyberspace cloud engulfing us the engram of our old fears will live for eternity - or at least until the software is updated to a version that can't read the original files. Total Recall is an extended corporate US manifesto, whose explicit slogan is: "I hate to lose my memories. I want total recall." The subtext is a bit more naive : I want total control over my life, I want immortality. If only I could record and store everything, I would become Homo eternicus. This is the same philosophy that feeds the US's mammoth pharmaceutical, food and health industries. The scheme seems ingeniously simple and technically feasible. To overcome oblivion, say the Totol Recall: How the e-memory

48 1 NewScientist 1 24 October 2009


For more reviews and to add your comments, visit www.NewScientist.com/books-art

bound to lead the miserable life of A. R. Luria's patient Solomon Shereshevsky, who was crippled by his boundless, indelible memory, or his fictional counterpart, Jorge Luis Borges's Funes. No forgetting implies no generalisation, no real present time, no amelioration of trauma, and no weaving of meaningful life narratives. Total recall may be beneficial for businesses and courts, clinics and insurance agencies, even possibly in settling occasional disputes with significant others, but rarely would it be deeply rewarding for the humble self. As its title suggests, Delete is about forgetting, more specifically about the demise of forgetting and the resulting perils. Viktor Mayer-Schonberger is worried by the same things that excite Bell and Gemmell. He observes how advanced information technology can allow the traces of every experience to chase us forever. Yet evolution has created the brain in such a way that the traces of experience do fade over time, receding into oblivion. Presumably, this offers us some kind of survival advantage - as Shereshevsky and Funes would attest. Mayer­ SchOnberger presents a scholarly discussion throughout, unlike the PowerPoint style of some chapters in Total Recall. And he comes up with an interesting solution: expiration dates in electronic files. This would stop the files from existing forever and flooding us and the next generations with gigantic piles of mostly useless or even potentially harmful details. This proposal should not be forgotten as we navigate between the urge to record and immortalise our lives and the need to stay productive and sane . • Yadin Dudai i nvestigates memory, and chairs the Department of Neurobiology at the Weizmann Institute of Science in Rehovot Israel

Save the to n g u e La n g uages a re dyi ng at a n a l a rm i ng rate, but this wa ke - u p ca l l shows a l l may n ot be l ost

been used by Jewish scholars since biblical times. Modern Hebrew's messianic proponent, the Zionist Eliezer Ben-Yehuda, faced stiff opposition to the plan. A fellow Jew sarcastically told him: "If you only speak a dead language to your children, you will make them idiots!" Still, it's amazing to consider that in the early 20th century, German almost supplanted Hebrew among Jews in Palestine, because of its use in technical schools. Einstein, inaugurating the Hebrew University of Jerusalem in 1923, managed just one sentence in Hebrew, then switched to his native German.

Tick tock A Tenth af a Second by Jimena

Canales, University of Chicago Press, $35 Reviewed by Pa u l Col l ins

"WE LIVE in a tenth­ of-a-second world," Thomas Edison's ...."""'-"' ... '-'> ..cJ electrical engineer ''-'''..::. ' Arthur Kennelly in Paris, has studied this decline �..L...I�=L' mused. That unit On the Death and Life af Languages for more than three decades. His is roughly human by Claude Hagege, Yale University academic book, On the Death and reaction time and, Press, £20/$30 Life ofLanguages, which was first as measurement technologies Reviewed by Andrew Robinson published in French in 2000 and improved, this bodily lag from has now been translated into EVERY year, stimulus to response became a English, is a wake-up call, covering vexing matter of observational 25 languages die languages across the globe, from interference. Jimena Canales ably out, on average. Cornish to the polyglot brew of shows it was brought to a head by The world has Papua New Guinea. Hagege has no astronomers recording the transit perhaps 5000 doubt that linguistic imperialism of Venus in 1874 : precisely timing living languages is largely responSible for the anything through an eyepiece was though estimates vary - so by the problem: "The death threat that bedevilled by human error. end of this century there will be Yet while this history of the weighs upon languages today takes the guise of English," he only half this number. In North unit thoroughly covers scholarly America alone, there were concludes glumly. "And I wager dialectic in science journals, the underlying experiments receive between 600 and 700 languages that the wisest anglophones would not, in fact, wish for a when Columbus landed in 1492. little attention. We learn that world with only one language." gunner reaction times were This number had fallen to 213 by studied by time-motion acolytes However, he also focuses on 1962, of which only 89 languages had speakers ranging from how a few dying languages, such in the trenches of the first world children to the elderly. Since as Welsh, have been saved by war, but only get hints of results. then at least 50 more have gone their native-speakers, assisted The unit's cultural role in sports by governments. The rebirth of measurement flickers by in a extinct. For example, the last native speaker of Cupeno died in Hebrew in Israel receives detailed mention. Still, it is a thoughtful 1987 in Pala, California, aged 94. treatment. Uniquely, Hebrew look at the all-too-human is a spoken language fabricated Claude Hagege, a professor of perceptual complications facing objective observation. linguistics at the College de France from a written language; it has 24 October 2009 1 NewScientist 1 49


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detection and quantitation of

M e d i m m u n e US

For more information visit NewScientistjobs.com job ID:

For more information visit NewScientistjobs.com job ID:

MD - M a ry l a n d

G e n etics ( M I H G H/ E M H S )

Principal Scientist - Biological Reagents &-amp; Assay Development

extracta bles and leachables i n

ME - Maine

G l axoS m ith K l i n e (GSK)

t h e biopharmaceutical products

The successful candidate w i l l have

PA - Pe n n sylva n i a

including recombinant protei ns,

strong biochemistry or proteomics

The successful candidate w i l l be

monoclonal antibodies and

expertise, preferably in human

respo nsible for the generation and

vacci nes.

cancer research, and several peer足

val idation of biological reagents for

reviewed publications.

use in developing cell-based assays

200605528

For more information visit NewScientistjobs.com job ID:

For more information visit NewScientistjobs.com job I D :

200599388

with research programs focused on understanding

lab, working with biochemical and

200599331

disorders.

For more information visit NewScientistjobs.com job I D :

professional work experience in a

training i n the transgenic models,

For more information visit NewScientistjobs.com job ID:

Post Doctoral Position

and biochemical assays.

200606416

neurodegeneration or promoting

The U n iversity of North Caro l i n a

neural repair, but outstanding

a t Chapel H i l l

Associate Director, Protein Production Systems

Bioinformatics, BMD Expert

applicants with a focus on basic

NC - N o rth Caro l i n a

I ntrexo n Corporation

Novartis I n stitutes for

aspects of neuronal function are

Work in o u r laboratory is focused on

MD - M a ry l a n d

B i o M e d i c a l Research (US)

also encou raged.

understanding how T cells and M H C

Mainta in knowledge of Intrexon's

MA - Massa c h u setts

50 I NewScie ntist 1 24 Octo ber 2009


www.NewScientistJobs.com

COLUMBIA UNIVERSITY

College of Physicians and Surgeons Assistant -Associate Professor Basic Pain Research The Department of Anesthesiology seeks an established and independent research scientist at the Assistant or Associate Professor level to develop a research program in the area of pain biology. It is expected that the successful candidate will be able to interact successfully with a large group of leading neuroscientists in the areas of ion channels, neuronal neuronal circuitry, and synaptic plasticity. The opportunity also exists for interactions with the clinical pain service. The successful applicant will have strong research interests in aspects of pain and will have a Ph. D . , M . D . , or Ph.D.lM.D. with postdoctoral training. The incumbent will have established a strong independent research program in basic laboratory and/or translational pain research with successful extramural funding and have the creativity and commitment to take his/her current program to a higher level offered by this recruitment. Please visit our online application site at hups://academicj obs. columbia.edu/applicants/Centra1?quickFind= 5 2 1 5 3 for further information about this position and to submit your application.

Columbia University is an affirmative action/equal opportunity employer.

Mďż˝('ďż˝

American Association ../71"1 " for CancerResearch

AACR Mem bership

Members Ded icated to Conquering Cancer Through Research, Education and Training, Communication and Col laboration

www.aacr.org/membership 2 4 October 2009 1 NewScientist 1 51


www.NewScientistJobs.com You w i l l design, i mplement and

Molecular Pathologist

apply cutting edge computational

Novartis I n stitutes for

Tenure-track Professors Ottawa. Ontario U n iversity of Ottawa

Tenure Track Faculty Position. Neurosciences. Retinal Degenerative Diseases at the University of Connecticut School of Medicine

methods to ana lyze genome-

B i o M e d i c a l Research (US)

sca le data generated from mRNA

MA - Massa c h u setts

ON - Onta rio

microa rrays, microRNA profiling,

Help establishing and

The successful candidates will

Deep Sequencing, and other high-

supervise molecular pathology

possess a strong background in

through put platforms.

laboratory activities in

molecular neuroscience applied to

U n iversity of Connecticut H e a lth

Molecular histopathology

clin ical ly-relevant research in stroke

Center

group in Cambridge, M A such

recovery.

For more information visit NewScientistjobs.com job I D :

200606630

as; I m m u nohistochemistry/ fluorescence (IHc/I F), i n-situ hybridisation (ISH)

Science Education Specialist Society for N e u roscience DC - D i strict of Co l u m bi a

The Science Education Special ist

For more information visit NewScientistjobs.com job I D :

200606680

(SES) will bring special ized knowledge a n d ski l l s that support the Public Education team to

For more information visit NewScientistjobs.com job ID:

200607206

CT - Connecticut

The applicant will be a PhD. and/ or M D. with experience in stem cells and a n interest in applying that expertise to nove l therapies of retinal diseases including macular

Director/Senior Director. R&D of Viology

degeneration.

M D - M a ry l a n d

200610542

Medimmune US

Field Application Scientist US (east coast)

We are seeking a senior virologist

For more information visit NewScientistjobs.com job ID:

successfu lly execute SfN's

F l u x i o n Biosciences I n e .

w h o w i l l b e respo nsible for leading

expanding education and outreach

U n ited States

initiatives, working cl osely with both

Fluxion Biosciences is cu rrently

and managing a team of 10+

researchers in the development of

Research Technician B. Stem Cell Research [1199] Yesh iva U n iversity

the neuroscience and education

looking for a Field Appl ication

large molecule drugs agai nst viral

com munities.

Scientist (FAS) to provide pre-sales

pathogens.

For more information visit NewScientistjobs.com job ID:

200607164

Associate Pharmacometrician (DI-Associate / D2-Sr. Associate

support of product demonstrations a n d post -sales customer appl ication support for the BioFlux product l i ne throughout North America.

For more information visit NewScientistjobs.com job I D : 200609170

For more information visit NewScientistjobs.com job ID:

culture and operation of complex

200608832

eq u i pment such as an HPLC and

Clinical Research Lead - Sr Director/Director

some holidays. Must mainta i n tissue cultures and support va rious

Pfize r U S

experiments.

liquid handlers. This position will req u i re a lternate weekends and

CT - Co n n ecticut

Motivates and engages col l eagues

C T - Co n n ecticut

Clinical Pathology Biomarker Scientist (R3)

The successful candidate will be

Pfizer US

excitement i n an indication and

Pfize r U S

NY - New Yo rk

Responsi b i l ities will include cel l

in an understanding of disease and

For more information visit NewScientistjobs.com job ID:

200610544

part of a global Pharmacometrics

CA - Cal ifornia

mechanism. - In colla boration with

Department worki ng in partnership

A c l i n ical laboratory scientist who

the RPL and the Research Project

with m u lti-disci plinary cli nical

will conduct all aspects of routine

Team ensures that the translational

Research Assistant C Molecular Biology

development teams of qua ntitative

and special ized flow cyto metry

research plan supports the strategy

Thomas J effe rson U n iversity

scientists.

assays in support of prec l i n ical and

for c l i n ical development.

PA - Pe n n sylva n i a

For more information visit NewScientistjobs.com job I D : 200606801

Fellow. Endocrine and Reproductive Toxicology (Cambridge)

c l i n ical studies.

For more information visit NewScientistjobs.com job I D : 200606803

The candidate will be responsible

Post-doctoral position available to study the molecular mechanisms of cell-cell interactions in mammalian development and physiology

for the design and set-u p of a

U n iversity of Ca l ifornia, S a n

N ovartis I n stitutes for B i o M e d i c a l Research (US) MA - Massa c h u setts

For more information visit NewScientistjobs.com job ID:

200606788

Will util ize and array of general and special ized laboratory tech niq ues including mammalian cel l culture; design, synthesis, and expression of wild -type and mutant plasmids

Assistant. Associate or Senior Scientist Geology and Geophysics Massachusetts W o o d s H o l e Ocea n o g ra p h i c I n stitution MA - Massa c h u setts

Woods H o l e Ocea nographic

new experimental laboratory and

Fra n c i sco (USCF)

I nstitution Assistant Associate

the management of 2 technical

CA - Cal ifo r n i a

or Senior Scientist T h e Geology

staff. The candidate will also

Post -doctoral position ava i lable to

and Geophysics Department

in bacteria and eukaryotic cells; l ive and fixed cel l light microscopy, routine biochemical and molecular biological tech n iques.

For more information visit NewScientistjobs.com job ID: 200608897

be responsible for su bseq uent

study the molecular mechanisms of

invites appl ications for two fu l l -

Postdoctoral Fellow position - BACTERIAL PATHOGENESIS - Texas

development implementation

cell -ce l l interactions i n mammalian

time ten u re-track positions at

Texas A&M Health S c i e n ce

and management of experi menta l

development and disease, using

the Assistant Associate or Senior

Cente r-Co l l e g e of M e d i c i n e

studies.

mouse as a model system.

Scientist leve l .

TX - Texas

For more information visit NewScientistjobs.com job I D :

200606657

52 1 NewScientist 1 24 October 2009

For more information visit NewScientistjobs.com job I D :

200608979

For more information visit NewScientistjobs.com job I D :

200609071

Our research emphasizes determination of the genetic req u i rements for virul ence and


www.NewScientistJobs.com persistence in a va riety of host

at VBI interpret and apply vast

models, as we l l as molecular and

amounts of biological data

biochemical characterization of

generated from basic research to

virul ence determinants.

some of today's key chal lenges i n

For more information visit NewScientistjobs.com job ID:

200610546

Post Doctoral Fellows in Cancer Biology T h o m a s J effe rson U n iversity

t h e biomedical sciences.

For more i nformation visit NewScientistjobs.com job I D :

200611265

E N G I N EERI NG

PA - Pe n n sylva n i a

Quality Engineer 3

Applicants should show particular

Boeing

interest in understanding the

FL - Florida

signa ling mechanisms as they

Represents Qual ity function on team

relate to nuclear hormone receptor

activities to integrate contractual

signa l i ng and cel l cycle regu lation in

and Boeing Quality Management

both breast and prostate cancers.

System requirements into all

For more information visit NewScientistjobs.com job ID:

200608905

Sr. Pathologist Nova rtis I n stitutes for B i o M ed i c a l Research (US)

aspects of proposa ls and program processes and documentation.

For more i nformation visit NewScientistjobs.com job I D :

200605985

Systems Engineer 3/4

MA - Massachusetts

Boeing

The incumbent will be responsi ble

C A - Cal ifornia

for providing pathology support

Test & Eva l uation systems engi neer

to Research with additional contributions to preclin ical safety

Cognitive Neuroscience Assistant or Associate Professor (tenure-track U niversity of Washi ngton I nstitute for Learning & Brai n Sciences

The U niversity of Washingto n 's I nstitute for Learn i n g & Brain Sciences ( I - LABS ) , an i n terdisci plinary brain resea rch center, has a tenure­ track facu l ty open ing for an Assista nt! Associate Professor i n Cognitive Neuroscience with a foc us on Language. Departmental affi liation can be in Psychology, Speech & Heari n g Sciences, Linguistics, or Biology, depend i n g on the applicant's background and trai n i n g . Ph . D. req u i re d . Appoi ntment at t h e Associate Professor level wi l l be considered for candidates who have a n outstanding research record . I - LABS' facu lty study life - long learn i n g and specialize i n human cognitive development and learn i n g . We have a growi n g developmental g rou p at the I n stitute. The I n stitute wi ll open its own MEG - B rain I m agi ng Center i n Apri l 2 0 1 O . The successfu l candidate wi l l be one who brings expertise in h u m a n cognitive neuroscience with a focus in the domain of language, development, and/or research using MEG / E RP. Facu lty responsibi lities wi ll begin Septem ber 1 6 , 201 0 . Applicants should send a statement o f teachi n g a n d research i n te rests, cu rric u l u m vita, u p to 5 pub lication reprints, and th ree letters of reco mmendation to: Patricia Kuhl, Co-Di rector, I n stitute for Learning & Brai n Sciences, Mailstop 3 5 79 8 8 , U niversity of Washi ngton , Seatt le, WA 9 8 1 9 5 ; e-mai l:

begin in fitted.

Review of applications wilt will continue until the position is

pkku hl@u.washington . e d u .

January 1 5 , 20 1 0,

The University of Washington is an affirmative action, equal opportunity employer, and is building a culturally diverse foculty and staff ond strongly encourages applications from women, minorities, individuals with disabilities

is responsible for the successful

and covered veterans. UW faculty engages in teaching, research and service.

execution of the FAB- T system

Faculty Career Flexibility, is committed to supporting the work-l ife balance

The University of Washington, a recipient of the 2006 Alfred P Sloan award for

assessment across the drug

term inal i nteg ration and system

development process.

test activities.

200606646

200606406

Instructor Position Endocrinology, Job ID 20145Texas

Software Developerl Arch itect

U n iversity of Texas M e d i c a l

Research ( U S )

Bra n c h at Ga lvesto n

B u i l d and d e p l oy re a l p roduction

Neurobiology & Physiology Tenure-Track Faculty Position

TX - Texas

syste ms with scient i sts who h ave

The Department of Neurobiology & Physiology,

This position is to conduct

h i g h expe ctat i o n s for q u a l ity,

College of Arts and Sciences, seeks to recruit a new faculty member at

independent basic research on

turnaro u n d , performance and

the Assistant Professor level. Applicants holding a Ph. D . and/or M . D .

adi pose tissue metabolism under

rel i a b i l ity.

degree and demonstrating a n outstanding record of scientific achievement

For more information visit NewScientistjobs.com job ID:

the d i rection of the Pri ncipal Investigator. The candidate will be expected to publ ish peer-reviewed manuscri pts and present resu lts at

For more i nformation visit NewScientistjobs.com job I D :

200611348

CH E M I STRY Postdoctoral Associate Microfluidics Specialist Virg i n i a B i o i nformatics I n stitute VA - V i rg i n i a

By using bioinformatics, which com b ines transd isci plinary approaches to information technology and biology, researchers

NORTHWESTERN

N ovartis I n stitutes fo r B i o M e d i c a l

For more i nformation visit NewScientistjobs.com job I D :

200613730

UNIVERSITY

in the Weinberg

will be considered. We are interested in individuals whose research addresses fundamental issues in neuroscience, including but not limited to neurogenetics, and who show signifi c ant potential fo r innovation, scholarship, and commitment to excellence in research and teaching. Successful candidates will be expected to establish and maintain a high­

scientific meeti ngs.

For more information visit NewScientistjobs.comjob ID:

of its faculty.

profile research program amacting substantial extramural funding.

Engineering and Public Policy at Carneg;e Mellon seeks doc­ toral students with technical backgrounds to address p olicy issues such as: electric p ower, en­ ergy and environment, advanced vehicles, nanotechnology, climate change; cybersecurity, privacy, IT policy; risk analysis and regula­ tion; management of innovation and R&D. Opportunities for dual­ degrees with Portugal available. See www.epp.cmu.edu. Victoria Finney, EPP, Carnegie Mellon, Pittsburgh, PA 1 5 2 1 3 USA

The

appointee will have access to state-of-the-art life science research support facilities and opportunities to interact with colleagues in the Institute for Complex Systems, Cognitive Neurobiology and Alzheimer's Disease Center, Center for Reproductive Science, Center for Sleep and Circadian Biology, Robert H . Lurie Comprehensive Cancer Center and an interdepartmental neuroscience graduate program with over 1 5 0 faculty. Applicants will submit (in PDF format) a cover letter, a CV, and a description of research plans. For details on preparing the application, please

visit

www.neurobiology.northwestern.edu.

Please

plan

to

request at least three letters of recommendation. Applications received by November 13 will be ensured full consideration. Please direct any questions to nbpfacultysearch@northwestern.edu.

AA/EOE.

Women and minority applicants are encouraged to apply. 24 Octo ber 2 0 0 9 1 NewScientist 1 53


www.NewScientistJobs.com

Faculty Position Genome Stability Group University of Pittsburgh Cancer Institute The U n iversity of Pitts b u rg h Ca ncer I n stitute (U PCI) a n d U n iversity of Pitts b u rg h has a strong progra m in G e n o m e Sta b i l ity a n d DNA Re pa i r a n d seeks t o recruit faculty at t h e j u n i o r a n d m i d-career sta g e t o d eve l o p outsta n d i n g resea rch progra ms that b r i n g a p p roaches co m p l e menting o u r existi ng stre n gths. T h e cu rre nt g ro u p co nsists o f Ch ris Ba kken ist, P h D (ATM s i g n a l i n g ; D N A d o u b l e-stra nd b rea k repa i r); La u ra N i e d e r n h ofer. P h D, M D (ERCC1; cross- l i n k re pa i r; mouse model of a g i n g a n d ca nce r); Patty Opres ko, P h D (DNA h e l i cases; te l o m e ri c DNA d a m age, repa i r a n d re p l i cation); Vesna Ra p i c-Otri n, PhD (da m a g e reco g n ition by DDB; D D B-CU L4 E3 l i gase and h isto n e u b i q u iti nation in chrom ati n); Robert Sobol, PhD (base excision re pa i r; PARP & NAD+ s i g n a l i n g and meta b o l ism; chemothera peutic a p p roaches i n bra i n ca n ce r); Ben Va n Ho uten, PhD (structu re-fu n ction

of re pa i r p rote i ns; m itoch o n d ri a l physiology); Yong Wa n, P h D ( u b i q u iti n-dependent p roteolysis; cel l cycle contro l ; DNA d a m a g e res ponses). U PCI a n d U n iversity of Pitts b u rg h h ave world-class s h a red fa cil ities i n c l u d i n g the Ce nter for B i o l o g i ca l I m a g i n g (Si m o n Watki ns, P h D) a n d the U n iversity of Pitts b u rg h Drug Discovery I nstitute (J o h n Lazo, Ph D). There a re opportun ities for exten sive col l a borations with i n the U n iversity of Pitts b u rg h M e d i ca l Ce nter and Ca rneg ie Mellon U n iversity, as we l l as opportun ities fo r participation i n re lated g ra d uate p ro g ra ms. Interested a p p l ica nts worki ng on problems i n a l l aspects of g e n o m e sta b i l ity, i n c l u d i n g , polymerase fidelity, DNA d o u b l e-stra n d b rea k re pa i r,

stru ctu re-fu nction stud i es of DNA re pa i r e n zymes a n d DNA d a m a g e responses, a re e n co u raged to a p p ly. We seek excepti o n a l ca n d i d ates u s i n g state-of-th e-a rt biochemical a n d m o l ecu l a r biol ogy tools worki n g in an a rray of b i o l o g i ca l syste ms. We a re a lso i nterested in ca n d i d ates com b i n i n g h i g h t h ro u g h put screens with bioi nformatic a p p roa ches fo r the a n a lysis of l a rg e data sets. Ca n d i dates with a track record of i n d ependent fu n d i n g a n d p u b l ications in h i g h i m pa ct j o u rn a l s w i l l be g iven the h i g h est con s i d e ration. S u ccessfu l ca n d i d ates wi l l be expected to run a vibra n t co l l a borative progra m s u p p o rted by external fu n d i n g . A co mpetitive s a l a ry and resea rch sta rt- u p packa g e wi l l be provided. The U n iversity of Pitts b u rg h School of M e d i c i n e is cons istently a m o n g the top ten in N I H-fu n ded m e d i ca l schools i n the U S a n d i s l o cated i n o n e o f Ame rica's most l iva b l e cities. Positions wi l l be coord i nated with Departments in the U n iversity of Pitts b u rg h and a re te n u re tra ck. To a p p ly, p l ease send you r cu rricu l u m vitae, a o n e-page s u m m a ry of yo u r resea rch p l a ns, and th ree l ette rs of reco m m endation to: Bennett Van Houten, PhD, UPCI Research Pavilion, Hillman Cancer Center Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863, email: vanhoutenb@upmc.edu. A p p l i cations wi l l be reviewed and eva l uated on

a n o n g o i n g basis. The U n iversity of Pitts b u rg h is a n Affi rmative Actio n , Eq u a l O p p o rt u n ity E m p l oyer.

Endowed Professorship for Dementia Research The Department of Neurology and the Neuroscience Center at the University of

Assistant Professor - Epilepsy Genetics

North Carolina, School of Medicine, Chapel Hill, are seeking candidates with an interest in degenerative neurological diseases that produce cognitive impairment.

The I n stitute for I nteg rative Genomics and Departme nts of N e u rology

1 -2

This will be a full-time faculty appointment as assistant, associate or full professor on

and Medicine, Va nderbilt U n iversity a re seeking to fi l l

the tenure track with rank and tenure determined based on academic qualifications,

track Assistant Professor positions to h e l p establish a new, i nter足

The qualified candidate will have an M.D. or M.D./Ph.D. and an established

d epartmental

record of excellence in research as reflected by peer-reviewed publications and

should have a Ph . D . , M . D'/Ph . D . or M . D . degree and sign ifica nt prior

independent external funding. He/she will be expected to conduct a laboratory足 based research program investigating mechanisms of cellular death and dysfunction in neurodegenerative diseases using state-of-the-art cellular and molecular techniques. The position includes an endowed professorship of $1 million, ample modern laboratory space in the UNC Neuroscience Center and a generous start足 up package. The UNC Neuroscience Center maintains outstanding Core Facilities that support confocal and multiphoton imaging, vector construction and ES cell electroporation for generation of mouse genetic models, and Affymetrix Gene chip technology for expression profiling and SNP analysis. Interested candidates who

research

Center for Genetic E p i l e psy

expe rience

i n the genetics,

Research .

genom ics,

new te n u re Candidates

neurophysiology

or n e u ropharmacology of e p i l epsy. We a re especially i nterested i n ca ndi dates who including

1)

s t u d y t h e m o l e c u l a r genetics o f h u man epil epsy

Mendel i an

epile psies,

2)

seizure

d i sorders

and

genetically

complex

util ize mouse or other animal models to map genes

responsible for e p i l epsy s uscepti bil ity or genetic/epigenetic modifiers of Mendelian epi lepsies;

3)

i nvestigate the n e u rophysiologica l basis

of e p i l epsy using bra i n sl ice el ectrophysiology or other i n n ovative methods;

4)

i nvestig ate the pharmacology or pharmacogenomics of

anticonvulsant treatments. S u ccessfu l ca n d idates w i l l be provided

are eligible to obtain a North Carolina medical license should send a cover letter,

wel l appoi nted laboratory space and generous start-u p fu nds to i n itiate

CV and four letters of references to :

their inde pendent research programs in the co llegial and col laborative

William J. Powers, M.D. H. Houston Merritt Distinguished Professor and Chair Department ofNeurology, University ofNorth Carolina School ofMedicjne

1 70 Manning Drive-Room 2 1 3 1 ., CB #7025 Chapel Hill, NC 27599-7025 Telephone: 9 1 9 966-81 78 powersw@lneurology.unc.edu

scie ntific environment of Va nderbilt U n i versity. Appropriate secondary acad emic appoi ntments a re antici pated in basic science de partments as wel l as affi l iations with other neurosci ence research centers (Vanderbilt Brain I n stitute , Center for Molecular N e u rosci ence). I nterested ca n d idates should send by email a cu rre nt C.v. , s u m m a ry of research experience and futu re plans, and names and addresses of three references as a s i n g l e P D F fi l e to:

EOE

UNC

S C HO O L O F ME D I C INE

54 1 NewScientist 1 24 October 2009

L

V .

Epilepsy Facu lty Selection Comm ittee Division of Genetic Medicine, 529 Light Hall Vanderbilt Un iversity Nashvi lle, TN 37232揃0275 Debora h . M . H olgui n@vanderbilt.edu

Vanderbilt University is an equal opportunity and affirmative action employer


www.NewScientistJobs.com

S c i e n c e S c h oLa rs h i ps a n d F e l l ows h i ps

T h e U N C F/ M e rc k S c i e n c e I n i t i a t ive i s a n i n n ova t ive a p p ro a c h t h a t c re a t e s o p p o rt u n i t i e s in t h e b i o Lo g i c a L

Northeastern Assistant/Associate/Full Professor

a n d c h e m i c a L s c i e n c e s f o r Afri c a n A m e r i c a n s t u d e n t s

Movement Neuroscience

t h ro u g h o u t t h e c o u n t ry.

Northeastern University, Boston, .MA The Departments of Biology and Physical Therapy at Northeastern

University

are

seeking

interdisciplinary

applicants in experimental or computational Movement Neuroscience. All ranks will be considered. Individuals working on neurophysiological, biomechanical and executive functions

in

the

control

of movement,

rehabilitation

and restoration of function, development, sensorimotor integration, muscle function and other areas related to motor control are encouraged to apply. We are interested in individuals with a variety of research methods ranging from

behavioral,

neurophysiological,

biomechanical,

electrophysiological, engineering and imaging techniques. Applicants will be expected to support a strong research program

and

contribute

to

teaching

in

the

area

of

neurobiology and biomechanics of movement at both the graduate and undergraduate levels. Successful applicants are expected to maintain an independent research program of distinction, as well as effective collaborations with other

U N D E R G RAD UAT E

S c i e n ce Resea rch S c h o la rs h i p Awa rds

faculty at Northeastern University and institutions in the

• S c h o la rs h i p s up t o $ 2 5 , 0 0 0

Boston area.

• Two p a i d i n t e r n s h i p s a t M e rc k R e s e a r c h La b o ra t o ri e s w i t h st i p e n d s t o t a l i n g m o re t h a n

$ 1 0,000

• M e n t o r i n g a n d n e t wo r k i n g o p p o rt u n i t i e s

Qualifications

• E l i g i b i l i t y : C o l l e g e j u n i o rs , s c i e n c e m aj o rs , 3 . 3 G PA

achievements and extramural funding commensurate with

include

a

strong

record

of

scientific

the level of the appointment, and a willingness to contribute

G RAD UAT E

S c i e n ce Resea rch D i sserta t i o n Fe llows h i ps

to undergraduate and graduate teaching.

• F e l lows h i p s u p to $ 5 2 , 0 0 0

• M e n t o r i n g a n d n e t wo r k i n g o p p o rt u n i t i e s

Start date: Fa11 2010.

• E l i g i b i l i t y : P h . D . o r e q u i va l e n t d e g re e c a n d i d a t e s e n g a g e d i n d i ss e rt a t i o n re s e a r c h i n b i o l o g i c a l o r c h e m i c a l research f i e l d s

To apply, visit the College website http://www.northeastern.edu/cas/

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S c i e n ce Resea rch Fellows h i ps

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AP P LY O N - L I N E

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24 October 2009 1 NewScientist 1 55


FEEDBACK

For more feedback, visit www.NewScientist.com/feedback

claim, this will inspire kids to take

system requirements as the cost

an interest in science, but Feedback

of shipping is non-refundable for

has reservations about blurring

items ordered incorrectly."

the distinction between space fantasy and space reality in this

Feedback suspects that some boilerplate text has crept erroneously

way. After all, there are already

onto the page, and that its intended

enough people who believe the

import is: "If you have a Mac and

Apollo 11 moon landings took place

buy a computer program that runs

in a Hollywood studio.

only on the Windows system, don't come crying to us." For ourselves, we run on DNA

WHEN you are selling education when dinosaurs roamed it." We wonder if this approach to packs for children, some of education will catch on with, for whose parents might be fervent creationists, one of the options example, packs on the second available is to, well, cave in to world war which invite your family's personal view on which them and ditch the education side won it. part. That seems to be the option chosen by US publisher Live and Learn Press with its dinosaur pack. Wendy Nicholas heard about WHICH American has spent the longest time in space? In case the pack from another parent you haven't been paying attention, who seemed to think that she would be delighted to know it's Buzz, who quietly returned about this curriculum resource. to Earth on 11 September after She was, until she read the blurb : more than 15 months on the "Dinosaurs . . . every child seems International Space Station. That's to go through a stage of loving Buzz Lightyear, the action figure them! We've made our Dinosaurs from the Toy Story movies, not Learn 'N Folder [sic1 to take Buzz Aldrin the Apollo astronaut. advantage of this love. Your child Surprise, surprise, Disney has made the most of the event. with a will learn about these creatures, how they ate, where they lived, ticker-tape parade earlier this month how we have come to know about for Buzz the action figure at Wait them, and much more. There is no Disney World's Magic Kingdom in reference to dates so you are free Orlando, Florida, led by Buzz the to insert your family's personal Apollo astronaut. view of the age of the earth and Perhaps, as NASA and Disney

DON'T mention the chemicals! Henry Bewley draws our attention to this neat little bit of verbal obfuscation by Nivea. Its Visage range, we are told on the Nivea web site - for example at niveaproduct.notlong.com "uses ingredients inspired by nature to create high performing products that work in perfect harmony with your skin". "That would be human-made, chemical ingredients, then," observes Henry. Yes, but the magic word "nature" is there, so everything's all right. Henry has a keen eye for this sort of thing. Back in Feedback on 14 January 2006 he reported that health store Holland &

version 1.0 with a 1010 neuron memory, whatever that is in bytes. Will that do for the rucksack?

READER Simon Rockett is the nominatively determined head of science at a secondary school in East Anglia, UK. "Pupils joke," he says, "that they are learning Rockett science. Oh, how I laugh." The other day he noticed a pile of recently delivered boxes of supplies in the school corridor. One was a box of Mini Jumbo Toilet Rolls. Intrigued, he wondered if the same company might also sell Jumbo Mini Toilet Rolls.

FINALLY, Jane Dards sends us a photo of a fine example of a self-referencing sign that she saw on the wall outside a shop in Newtown, Powys, UK. The sign, which is fixed at right angles to the building, reads "Caution, protruding sign". Jane finds the fact that the sign is quite battered, presumably by incautious lorry drivers who have ignored its message, particularly appealing. After some thought about why the sign might exist. she reasoned that its other side

Barrett was using the same trick to avoid admitting that its ABC -plus vitamin range is made of chemicals as opposed to "natural" ingredients. It labelled the product "naturally inspired".

must have the real message on it. such as "Caution, pedestrians crossing" or some such warning. So she walked round and had a look, only to find that it had diagonal yellow and black hazard stripes, but no writing on it at all.

"Ha i r Loss Result G u a ra nteed!" proc l a i ms a n advert fo r the U K Adva nced H a i r Stu d i o . Ant Astley suspects it wou l d be cheaper s i m ply to shave it off h i mself 56 1 NewScientist 1 24 October 2009

AIMING to purchase a bag online, Paul Brown came across a folding rucksack at rucksack-system. notlong.com. Beneath the product description was this warning: "Please ensure that you have the correct

Vou can send stories to Feedback by email at feedback@newscientist.com. Please include your home address. This week's and past Feedbacks can be seen on our website.


Last words past a n d prese nt, p l u s q u esti o n s, at

THE LAST WORD

www. l a st-wo rd . co m

Air spray

trapped and its concentration increases. Initially it remains dissolved, because cold liquids I wanted to c h i l l a mug of water so can hold more dissolved gas than placed it in the freezer, but then forgot about it a n d it froze s o l i d . hot ones. This is why the outer W h e n I removed the b l o c k of ice layer is almost free of air bubbles. However, the concentration of from the mug it contained the dissolved air eventually exceeds most amazing thistl e - l i ke pattern of what seemed l i ke canals of a i r (see the ability of the water to retain it photo). None of these canals in solution, so air bubbles begin to exte nded to any outside s u rfaces. form and get trapped in the ice as What happened? the crystals grow inwards, forming the patterns observed. The lines all curve downwards because • The simple answer is that because you live in Somerset water on the verge of freezing is West, South Africa, you should ask less dense than slightly warmer your neighbour Jon Richfield, who water, and so rises. Thus the water freezes from the top down, meaning that the water at the bottom (which is also somewhat insulated from the cold air in the freezer) is the last to freeze. Simon Iveson Department of Chemical Engineering University ofNewcas tie Cal/aghan, New South Wales, Australia And, of course, fon didprovide an answer- Ed

In this case, the front advanced smoothly along the curves described by the long bubbles. The original spherical bubbles caught in place by the growing crystals acted as nuclei into which the rest of the gas collected as it escaped from solution. Being surrounded by ice in every direction except perpendicular to the ice surface, the bubbles formed tubes whose shapes traced the advance of the crystal-water interface. It's common to see such bubble growth, but the lovely symmetry

"The lovely symmetry req uires still water and suitable temperature gradients and solutes" and consistent bubble structure shown in the photograph require still water and suitable solutes, temperature gradients and crystal forms. To sculpt such bouquets in various forms, and possibly in other media, should make for satisfying science experiments and art projects. fon Richfield Somerset West, South Africa

answers so many of the questions on this page. Just in case Jon can't help, I'll venture an opinion. In the freezer the water is cooled from the outside in. So the first crystals of pure ice form around the outside of the mass of water. As these ice crystals grow inwards, the air dissolved in the water becomes

If the container is smooth, the outer layer is bubble-free because solutes in the water, gases in particular, are unsaturated when freezing starts. Bubbles form only after some ice has formed, forcing enough gas to supersaturate the surrounding water. Initially, tiny spherical bubbles appear on the advancing surface. What happens next depends on the path of the ice front and the form of the growing crystals.

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Spice attack

blood and exit via lungs, urine, sweat, saliva or sebum, more than most people notice. As a result, families or communities with distinctive cuisines have distinct body scents. There are many examples beyond obvious ones such as asparagus and onion-like foods. Stewed mutton and beef give a recognisable odour to one's urine. No doubt any self-respecting dog could identify other meats. Many nitrogen compounds are particularly likely to be excreted in urine or sweat. I rather like the yeasty smell of thiamine, but my wife hates it, as does a friend who once had to have daily thiamine injections. His skin would reek before the doctor even finished the injection. Some people can even guess which cheese you have eaten in the last few days; presumably the smell gets into your sebum. Fenugreek contains a range of sulphur and nitrogen-rich aroma molecules that the body modifies and excretes in breath and sweat, but the main burnt -sugar smell comes from the lactone sotolon, whose smell we can detect even in minute concentrations. Antony David Watford, Hertfordsh ire, UK

The Last Word has t o l d us w h y garlic makes yo u r breath and body smell,

This week's question

but I want to know why the spice methi, o r fresh fe n u g re e k, has a

RISE AND FALL

s i m i l a r, possibly stronger, effect.

Why are the largest tide ranges in the world - of up to 16 metres ­ found in the Bay of Fundy, on Canada's Atlantic coast? Peter Buckley Toronto, Canada

• Depending on their biochemical nature, volatile components of foods or their metabolic products enter the

Do Polar Bears Ciet Lonely? Our latest col lection serious e n q u i ry, bri l l iant i n s i g ht and the h i l a riously u n expected

Available from booksellers and at www.newscientist.com/ polarbears


Why so

.e.

pÂŁ.opl(, think

make.s chocolate.

f Grass,

KIDS DON'T G ET ENOUGH

reinvented

ART THESE DAYS,

So It'S no

expanding and editing It

wonder that some of them

in an e ffort to pu b l i s h his

mistake A m e r i c a ' s most

quintessential collection. In

Lea1!es

o

Lea1!es of Grass was WaIt

revolutionary poet for a

essence,

box of chocolat e s .

himself in verse form. Wa I t

The son o f a Qgaker

Whitman c h a n g e d poetry.

carpenter, Wait Whitman

H I S l i fe 's work was ahead

grew up with an affinity

of its time. And though

for n a t u r e . T h i s , along

he lived long before the

w i t h his love for N e w

Summer of Love, he was

York City, inspired him

the ongmal beatmk - an

to write a truly original kind of poetry, the likes of

WhJtman satISfied hIS sweet tooth wlth mh, wave,lrke verse. Every kid should make poetry a part of hIS diet.

inspiring example for writers like Gmsberg and Kerouac .

w h i c h A m e r i c a h a d never s e e n . H i s c o l l e c t i o n

W h l tman can I n flu e n c e

f

your child, too. That's what

Due to its h e d o n i s t i c , s e n s u a l ,

art does. In fact, the more art

e v e n n a r c i s s i s t i c subj e c t m a t t e r , t h e

kids get , the smarter they

poems w e r e often banned. T h i s guy

become in subjects like math

pushed the envelope all right, before

and science. So they become

most folks even knew there was an

more

of poems b e came known as

Grass.

much of WhItman's art won't g1ve you a stomachache.

Too

candy

Lea1!es

o

e n v e l o p e to p u s h . Throughout his career, Whitman rewrote and

For

well-rounded

Ten SImple Way s

adults .

: 'RITING GIve your ktds a chance succeed. Up therr dally dose of art.

to

to g e t more a r t i n k i d s '

l i v e s , V I S i t Amen c a n s ForTheArts . o r g .

New_Scientist_24102009  

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New_Scientist_24102009  

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