the ou delusion -...

WEEKLY 8 September 2018

TWO DECADES MORE Embryo gene tweaks to

vastly extend lifespan

EARTH’S ALIEN PASTOur planet’s hidden clues

to life elsewhere

APOCALYPSE NEVERSci-fi genius Cixin Liu

predicts the future

PLUS ANTI-POLLUTION PRAMS / MUMMIFIED PENGUINS / EUROPA’S MYSTERY COLD SPOT / DESALINATION’S DIRTY SECRET

HYDROGEN RESURGENCEThe battle for the future of clean cars

THE YOU DELUSIONWhy your sense of self isjust a trick of the mind

9 7 7 0 2 6 2 4 0 7 2 8 2

3 6

No3194 £4.50 US/CAN$6.99

РЕЛИЗ ПОДГОТОВИЛА ГРУППА "What's News" VK.COM/WSNWS

8 September 2018 | NewScientist | 1

CONTENTSnewscientist.com/issue/3194

Leader

3 We should be open to the idea that

human intelligence isn’t as special

as we like to think

News

4 THIS WEEK Crunch time for

Ebola. Brazil National Museum fire.

Race to save Opportunity. Find

your heart age. The reality of the

American dream

6 NEWS & TECHNOLOGY

Mummified penguins. Dark matter

blasted. Laser-powered drones.

DNA editing before birth. Europa’s

mystery cold spot. How you type

could reveal Parkinson’s. Do AIs

know what we are thinking?

Corals fight the heat. Pram

design can cut air pollution risk.

Overworked brains. CRISPR helps

dogs’ muscle disease. Fish pass

the mirror test

17 IN BRIEF Elk antler gamble.

Non-addictive opioid. Warm water

threatens Arctic. AI tracks cancer.

Print with sound and honey

Analysis

20 INSIGHT Why your next car could

run on hydrogen

22 COMMENT The lunar gateway

is a terrible idea. Why Americans

should vote for a scientist

23 ANALYSIS Is self-harm in UK

teens rising?

Features

28 The you delusion Why your

sense of self is just a trick of

the mind

32 The briny deep Ocean

desalination could provide drinking

water for all – if only we knew

what to do with the waste salt

36 The surgeon fixing a scandal

We could have avoided the worst

consequences of vaginal mesh,

says Sohier Elneil

38 Earth’s alien past Our deepest

history may hold the key to the

search for life on other planets

Culture

42 Apocalypse never China’s

sci-fi genius Cixin Liu on why our

future is bright. PLUS: This week’s

cultural picks

44 A fantastical experiment

Ceramic art acts as a foil for a

collection of scientific curios

Regulars

24 APERTURE

Eye to eye with a hawkmoth

52 LETTERS

Polluter pays - but to whom?

55 CROSSWORD

56 FEEDBACK

The politics of alien abduction

57 THE LAST WORD

Eggstraordinary claim

On the cover

38 Earth’s alien past

Our planet’s hidden clues

to life elsewhere

7 Two decades more

Embryo gene tweaks to vastly

extend lifespan

42 Apocalypse never

Sci-fi genius Cixin Liu predicts

the future

28 The you delusion

Why your sense of self is just

a trick of the mind

20 Hydrogen resurgence

The battle for the future of

clean cars

Anti-pollution prams (13).

Mummified penguins (6).

Europa’s mystery cold spot (8).

Desalination’s dirty secret (32)

News Critical moment for Ebola outbreak in the DRC 5Volume 239 No 3194

JOH

N W

ES

SE

LS

/AF

P/G

ET

TY

IMA

GE

S

KIM

RO

SE

LIE

R

Plus

ManagementExecutive chairman Bernard Gray

Finance director Jenni Prince

Chief technology officer Chris Corderoy

Marketing director Jo Adams

Human resources Shirley Spencer

Non-executive director Louise Rogers

Publishing and commercialCustomer services manager Gavin Power

HR co-ordinator Serena Robinson

Facilities manager Ricci Welch

Executive assistant Sarah Gauld

Receptionist Alice Catling

Display advertising

Tel +44 (0)20 7611 1291

Email [email protected]

Commercial director Chris Martin

Richard Holliman, Justin Viljoen,

Henry Vowden, Helen Williams

Recruitment advertising

Tel +44 (0)20 7611 1204


Recruitment sales manager Mike Black

Key account managers

Martin Cheng, Reiss Higgins, Viren Vadgama

US sales manager Jeanne Shapiro

Marketing

Head of marketing Lucy Dunwell

David Hunt, Chloe Thompson, Andrew Wilkinson

Web development

Maria Moreno Garrido, Tom McQuillan,

Amardeep Sian

New Scientist Live

Tel +44 (0)20 7611 1206


Creative director Valerie Jamieson

Sales director Jacqui McCarron

Exhibition Sales Manager Charles Mostyn

Event manager Henry Gomm

Conference producer Natalie Gorohova

Head of marketing Sonia Morjaria-Shann

Marketing executive Sasha Marks

UK Newsstand

Tel +44 (0)20 3787 9001

Newstrade distributed by Marketforce UK Ltd,

2nd Floor, 5 Churchill Place, Canary Wharf,

London E14 5HU

Syndication

Tribune Content Agency

Tel +44 (0)20 7588 7588


Subscriptions

newscientist.com/subscribe

Tel +44 (0)330 333 9470


Post New Scientist, Rockwood House,

Perrymount Road, Haywards Heath,

West Sussex RH16 3DH


DO

MIN

IQU

E F

AG

ET

/AF

P/G

ET

TY

IMA

GE

S

LEADER

EditorialEditor Emily Wilson

Managing editor Rowan Hooper

Art editor Craig Mackie

Editor at large Jeremy Webb

News

News editor Penny Sarchet

Editors Jacob Aron, Timothy Revell, Jon White

Reporters (UK) Andy Coghlan, Alison George,

Jessica Hamzelou, Michael Le Page,

Clare Wilson, Sam Wong

(US) Leah Crane, Chelsea Whyte

(Aus) Alice Klein

Features

Chief features editor Richard Webb

Editors Catherine de Lange, Gilead Amit,

Julia Brown, Daniel Cossins,

Kate Douglas, Joshua Howgego,

Tiffany O’Callaghan, Sean O’Neill

Feature writer Graham Lawton

Culture and Community

Editors Liz Else, Mike Holderness, Simon Ings,

Frank Swain

Subeditors

Chief subeditor Eleanor Parsons

Tom Campbell, Hannah Joshua, Chris Simms

Design

Kathryn Brazier, Joe Hetzel,

Dave Johnston, Ryan Wills

Picture desk

Chief picture editor Adam Goff

Kirstin Kidd, David Stock

Production

Mick O’Hare, Melanie Green ,

Alan Blagrove, Anne Marie Conlon

Contact us

newscientist.com/contact

General & media enquiries

Tel +44 (0)20 7611 1202

[email protected]

UK

25 Bedford Street, London, WC2E 9ES

Tel +44 (0)20 7611 1200

AUSTRALIA

PO Box 2315, Strawberry Hills, NSW 2012

US

210 Broadway #201

Cambridge, MA 02139

Tel +1 617 283 3213

© 2018 New Scientist Ltd, England

New Scientist is published weekly by New Scientist Ltd. ISSN 0262 4079.

New Scientist (Online) ISSN 2059 5387

Registered at the Post Office as a newspaper and printed in England by William Gibbons (Wolverhampton)


WE LIKE to think that the human mind is special. One sign of our superiority is self-awareness, which is generally seen as the pinnacle of consciousness. Only a select group of species has passed the test of being able to recognise themselves in a mirror. Most, including elephants, apes and dolphins, are notoriously smart. But now a scrappy little fish, the cleaner wrasse, has joined their ranks (see page 14). What are we to make of this?

Admittedly, the mirror test is a questionable way of probing the minds of other animals. But the finding does fit with an emerging idea that the ability to recognise

oneself is more related to an animal’s lifestyle than to its brain size. Self-awareness is likely to occur in creatures whose survival is dependent on reading the minds of others. In fact, by this way of thinking, it is nothing more than an accidental by-product of evolution, a simulation created by the brain, or even just a hall of mirrors giving the illusion of complexity (see page 28).

The cleaner wrasse lives on coral reefs and provides a service by nibbling parasites off the scales of bigger fish, a delicate relationship that may require insight into the minds of its clients. Such “theory of mind”

has long been seen as another cornerstone of human mental superiority. The possibility that fish possess it is not, however, the only threat to our human exceptionalism. It may not be long before computers give us a run for our money, too.

Researchers have created a set of tests to look for theory of mind in artificial intelligence – and some systems are on the verge of passing (see page 10). We probably don’t need to worry about robots that can recognise themselves in mirrors. But we might want to be more open to the idea that human intelligence isn’t quite as special as we like to think.

Like looking in a mirrorWe’re not unique – lots of species can recognise themselves

There are only two weeks to go

now until New Scientist Live. The

four-day show is a unique mixture

of fascinating talks from scientists

and an amazing array of exhibits,

from a slime Olympics to a virtual

reality tour of the brain. It’s an

enormous and joyful celebration

of ideas, and we call it “the world’s

greatest science festival”

because we really think it is.

Last year, more than 30,000

people came through the doors

at ExCeL in London and it was

a privilege for us to get to

know so many of you. If

you’re in striking distance

from 20 to 23 September

this year, please come

along. I’m most looking

forward to introducing

astronaut Tim Peake’s

talk on the Thursday,

but whatever day you

come, there will be

something brilliant

going on. Check out

the programme at

newscientistlive.com.

Emily Wilson

A NOTE FROM THE EDITOR


4 | NewScientist | 8 September 2018

THIS WEEK

IT IS the American dream that

anyone can become prosperous

through hard work, irrespective of

their status at birth – but the reality

is different. The socio-economic

status of someone in the US is more

strongly influenced by that of their

parents than previously thought.

Michael Hout of New York

University looked at data from 21,000

people, each given a “socio-economic

index” (SEI) score – a measure of pay

and credentials ranking 0 to 100, with

0 representing the lowest in society.

The data included questionnaire

answers that helped establish the

SEI scores of the people’s parents.

The American dream suggests that

anyone can achieve a high SEI score,

but Hout found otherwise. It turned

out that there was a strong linear

relationship between someone’s SEI

score and that of their parents (PNAS,

DOI: 10.1073/pnas.1802508115).

Earlier studies have hinted at such

“intergenerational persistence”, says

Hout, but not to such a strong degree

as his findings suggest.

TIME is running out for NASA’s

Opportunity rover. A dust storm that

has been raging on Mars since early

June is starting to subside, potentially

giving the rover enough sunlight to

charge its batteries. But on 30 August,

NASA set a 45-day deadline before it

gives up trying to wake it.

The Opportunity rover runs solely

on solar power, so a dust storm like

this one, which has blocked out more

than 99 per cent of sunlight on Mars’s

BU

DA

ME

ND

ES

/GE

TT

Y

surface, can be catastrophic. The last

signal received from Opportunity was

on 10 June. Since then, it has been in

sleep mode, using any power it has

left to keep its batteries warm enough

to survive on the frigid surface.

Now that the planet-encircling

storm has begun to clear, rover

operators are sending Opportunity

wake-up calls three times a week with

orders to send back a beep if it is alive.

The hope is that sleep mode kept the

battery safe, and that a Martian dust

devil will soon come along and blow

the sand off the rover’s solar panels,

allowing it to charge up again.

HEALTH chiefs in England this week

launched an online “heart-age” test,

which is claimed to reveal people’s

risk of a heart attack or stroke. Public

Health England (PHE) says that if a

person’s heart is “older” than their age,

they are at increased risk and should

consider diet and lifestyle changes.

PHE says that of 1.9 million who

have already tried the test, 78 per

cent had hearts older than their age.

In 14 per cent, their hearts were

10 years older. But critics say the

test – which asks simple physical and

lifestyle questions – could create

unfounded alarm by basing estimates

on incomplete data.

It asks for accurate measurements

of blood pressure and cholesterol, but

if these are not available, it seems to

assume abnormal values, potentially

overestimating heart age. “I just

entered this as a 30-year-old with

no risk factors, and it told me to get

cholesterol and blood pressure-

tested,” tweeted Margaret McCartney,

a family doctor in Glasgow, UK. “Where

is [the] evidence of benefit?”

Doubts raised over online heart test

Race to save Mars rover Opportunity

American dream is slipping away

NA

SA

/JP

L

Treasured artefacts lostBRAZIL’S oldest and most important

scientific museum was gutted by

fire on 2 September. Within hours,

the blaze destroyed many priceless

scientific artefacts and collections

gathered since the National Museum

was founded in 1818.

Items potentially lost include

the massive Bendegó meteorite,

weighing 5260 kilograms, and Luzia,

a 12,000-year-old human skeleton,

the oldest in the Americas.

Based in Rio de Janeiro, the

museum housed irreplaceable

collections of scientific artefacts,

specimens and records in geology,

botany, biology, palaeontology and

zoology, as well as priceless cultural

and anthropological artefacts. Almost

90 per cent of the 20 million items

there are thought to have been lost.

“It is incalculable for Brazil to lose

the collection of the National

Museum,” said Michel Temer, Brazil’s

president, in a statement reported by

The Rio Times. “200 years of work,

research and knowledge were lost.”

Media sources report that the

fire began between the museum

closing at 5 pm as usual on Sunday

2 September and 7.30 pm.

Some reports claim that two

key fire hydrants on site were dry,

preventing firefighters from tackling

the fire in the early stages. Other

reports say that successive

governments had allowed the

museum to fall into disrepair.

The Brazilian government says it

is now seeking corporate funding to

help rebuild the museum. Officials are

also seeking international help and

are speaking to UNESCO, the cultural

agency of the United Nations.



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

THE Ebola outbreak in the Democratic Republic of the Congo (DRC) has reached a critical juncture. It seems to be subsiding, after striking 121 people and killing 81 as of 2 September. But the coming days may be crucial, says Tedros Ghebreyesus, head of the World Health Organization (WHO).

That is partly because the outbreak is in North Kivu province in the war-torn east of the DRC, where fighting by more than 50 armed groups puts many areas off limits.

To stop the virus spreading, medical teams must isolate and vaccinate anyone who has had contact with an infected person, and all the people they in turn came into contact with. But the teams can’t work much more than 30 kilometres from the epidemic’s centre in the city of Beni.

Worse, the UN’s International Organisation for Migration (IOM) has found that people in the region are highly mobile, with traders and miners transiting to Uganda and Rwanda, and a million people have been displaced by violence.

Such high population mobility, plus a slow medical response, caused an Ebola outbreak in West Africa to mushroom into an unprecedented epidemic that killed more than 11,000 in 2014.

This time, the response has not been slow. The outbreak was recognised on 1 August, only a week after an Ebola epidemic on the other side of the DRC had been halted. A week later, teams in North Kivu were vaccinating.

This selective “ring vaccination” of the contacts of known cases, then their contacts, makes best use of limited vaccine stocks by containing virus spreading from known cases. It seems to be working: on 1 September, with

5462 contacts vaccinated, the WHO reported 13 new cases the previous week, down from 25 and 35 in the weeks before that.

If that continues, the 300,000 doses of vaccine available worldwide should be more than enough to contain this epidemic. But epidemics can hit tipping points and soar exponentially.

Stopping that requires stopping all the chains of transmission, says Mike Ryan, head of emergency response at the WHO.

Moreover, Ebola epidemics come in waves: the next surge could be incubating, or invisible in violent no-go areas. Worryingly, four of the new cases reported last week were not from known chains of transmission, so there are unknown chains out there.

They may be hard to find. The IOM has used its data to choose

the 34 most important transport hubs where people leave the region, and Congolese authorities have so far checked 840,000 travellers there for symptoms.

It has also mapped highly vulnerable spots, such as popular markets and churches with strong connections to the outbreak zone, for closer monitoring.

But the IOM is only able to monitor relatively safe zones. “The news of two confirmed cases in Oicha is extremely distressing, because the area is almost entirely surrounded by armed militants,” says Michelle Gayer of the US-based International Rescue Committee.

Last week, a medical team with a heavy UN military escort vaccinated 97 contacts of the two infected people in Oicha, discovered only because one travelled to Beni. Anyone in the area around Oicha cannot be reached.

The WHO also last week decided to test three antiviral drugs in randomly chosen patients. No one will get a placebo, so the trials

can’t establish formally how much better the drugs are than getting no drug. But they can compare the three.

Two people have received ZMapp, a cocktail of antibodies, the immune proteins that attack the Ebola virus. It showed promise in 2014, but is hard to administer and must be stored at −80°C, which is difficult in the DRC. Five have had remdesivir, a molecule that blocks the infection process.

The big surprise is that 13 have been given mAb114, an antibody from a survivor of the 1995 Ebola epidemic in Kikwit, DRC, which can be kept in a refrigerator and needs only one simple injection.

Last year, a WHO panel judged it too untested to use in epidemics, but the US National Institutes of Health has since rushed through safety trials in humans. Two people on it have recovered, says the WHO, but it is not yet known if the drug helped. ■

Crunch time for Ebola in the DRCWar zones may thwart efforts to halt virus, reports Debora MacKenzie

JOH

N W

ES

SE

LS

/AF

P/G

ET

TY

IMA

GE

S

A church service near Beni, DRC, the epicentre of an Ebola outbreak

“ Ebola comes in waves: the next surge could still be incubating, or invisible in violent no-go areas”



NEWS & TECHNOLOGY

Michael Marshall

MUMMIFIED penguins have been found littering the ground in Antarctica. The birds seem to have died during two bouts of extreme weather over the past 1000 years. Such conditions are expected to become more common as a result of climate change, making mass die-offs more likely.

The birds were found on Long Peninsula, in east Antarctica, by researchers led by Liguang Sun at the University of Science and Technology of China in Hefei.

It isn’t unusual to find dead penguins, but those on Long Peninsula – mainly chicks – are especially numerous, with up to 15 per square metre and hundreds overall. “They consist of well-preserved dehydrated mummies,” the researchers write in a paper.

All are Adélie penguins (Pygoscelis adeliae), which only live in Antarctica. They currently breed in the Antarctic summer at about 250 sites, forming huge colonies near the coast.

To find out what happened on Long Peninsula, Sun’s team used carbon dating to estimate the ages of the corpses. They also studied

sediments, which contain excrement and nest material.

They found that penguins have lived there for at least 3900 years, but most of the deaths occurred in two periods, about 750 and 200 years ago. The colonies were abandoned afterwards each time, as little new sediment was laid down in later centuries.

The cause seems to have been unusually heavy snow or rain over several decades. The team found evidence of floods that carried

sediment and corpses downhill, and signs of erosion (Journal of Geophysical Research: Biogeosciences, doi.org/ctj9).

Rain is a lethal threat, says Yan Ropert-Coudert of the French National Centre for Scientific Research. “The chicks especially are not made for wet weather,” he says. Hypothermia is a risk. Meanwhile, snow makes it hard for parents to find pebbles to make nests, and if it melts the meltwater can drown chicks.

The cause of the wet weather was probably a shift in the Southern Annular Mode, a pattern of winds in the Southern Ocean

that can send extra damp air to east Antarctica. Climate change is likely to make this more frequent.

Adélies are widespread, so can handle occasional disasters, says Steven Emslie at the University of North Carolina Wilmington. But they face increasing pressures. In April, Emslie published a study of the largest modern Adélie colony, at Cape Adare. “Sea level rise is going to displace hundreds of thousands of penguins there and at Cape Hallett within the next 30 to 50 years, as those beaches are gradually inundated,” he says.

Ropert-Coudert has detailed the disastrous 2013-14 breeding season, when no chicks survived in a major colony on Petrel Island in east Antarctica. Unusually heavy snowfall killed them, combined with weak winds that failed to break up the sea ice, preventing adults from catching enough food. And it wasn’t a one-off. “In 2016-17 we had a second massive breeding failure in the same place,” he says.

According to the International Union for Conservation of Nature, Adélie penguins are at low risk of extinction. But Ropert-Coudert says repeated breeding failures on Petrel Island are a bad sign. The solution is to limit climate change as much as possible, he says. We could also set up protected areas to “prevent other threats from superimposing on the climate ones”. ■

Graveyard is a bad omen for penguins

HIR

OY

A M

INA

KU

CH

I/M

IND

EN

PIC

TU

RE

S/F

LP

A

“ Dark matter density should increase as you move to the centre of a galaxy, but some didn’t get the memo”

THE dark matter in small galaxies has

been giving cosmologists a headache.

Blowing up a few stars may provide

the solution.

Dark matter is thought to make

up most of the matter in the universe

and should be found mixed in with

the regular matter of galaxies. The

standard model of cosmology, called

lambda-CDM, predicts that the density

Star explosions could explain misfit galaxies

of this dark matter should increase

as you move towards the centre of a

galaxy, but some dwarf galaxies didn’t

get the memo: they have a constant

density of dark matter.

That might seem a minor wrinkle,

but if it can’t be explained within

lambda-CDM, it could deal a blow to

our understanding of dark matter.

“The implications of these very

subtle measurements are large

so people have argued a lot over

them,” says Marla Geha at Yale

University, who wasn’t involved

in the latest work.

Star formation is one potential

explanation. Some stars are born

after old ones die in explosive

supernovas, which send matter flying.

Bursts of such star formation in small

galaxies might blow some dark matter

towards the edges, smoothing out

the distribution.

Justin Read at the University of

Surrey in the UK and his colleagues

used measurements of the mass at

the centres of dwarf galaxies to test

this idea. They picked out samples of

two different types of galaxy, eight

that stopped forming stars long ago,

and eight that are still forming stars

or only stopped relatively recently.

They found that the galaxies with

higher rates of star formation had less

dark matter in their centres, pointing

to a more uniform distribution. That

matches up with the idea that star

formation moves mass towards

the edges of the galaxy, which then

shifts the dark matter outward.

It’s a good sign for lambda-CDM,

if the result stands up (arxiv.org/

abs/1808.06634). Leah Crane ■

Climate change threatens the Adélie penguins of Antarctica



MAKING dozens of changes to DNA in human egg and sperm cells or very early embryos could dramatically extend the lifespan of offspring – according to the first attempt to quantify potential benefits of germline genome editing.

“This… shows that we could potentially use germline gene editing to make us all resistant to diseases of old age,” says biomedical ethicist Christopher Gyngell at the University of Melbourne, Australia, who was not involved in the study.

It is already possible to prevent genetic diseases caused by single mutations, such as cystic fibrosis – by screening IVF embryos before implantation, for instance.

But we all carry thousands of gene variants that don’t inevitably lead to diseases, yet affect our risk of developing them. Changing one wouldn’t have a big impact, but changing many could potentially add years to lives that would otherwise be cut short. This may be possible in the next few

decades, says Roman Teo Oliynyk, a computational biologist at the University of Auckland, New Zealand. For instance, CRISPR genome editing has been used to make multiple changes to animal egg cell genomes.

Oliynyk looked at gene variants known as SNPs that affect the risk

of developing diseases of old age, including heart disease, type 2 diabetes, stroke, Alzheimer’s, osteoarthritis and some cancers. From these it is possible to estimate whether a person has a greater or lower risk of developing these diseases.

Oliynyk modelled what would happen if those with a higher-than-average risk had undergone genome editing before birth to reduce their risk to the average. This would mean altering dozens of SNPs – even hundreds in those

with the highest risk. The findings suggest the results would be dramatic, with people on average living many years longer before developing these diseases.

The benefits would be greatest for cancers. Those treated would live two decades longer, on average, before developing breast, prostate or colorectal cancers, and their lifetime risk would be more than halved, even if they live 10 years longer (bioRxiv, doi.org/ctjp).

However, as Oliynyk acknowledges, his conclusions depend on several assumptions. One is that we have correctly identified SNPs that affect disease risk. In reality there is still huge uncertainty. “I don’t think we are there yet. I’m not sure we ever will be,” says geneticist Helen O’Neill of University College London.

She points out that the effect of gene variants can depend on the environment and other gene variants and may prove impossible to accurately predict.

Another assumption is that altering SNPs has no side effects, says Ali Torkamani of the Scripps Research Institute in La Jolla, California. “There is often a trade-off to be had – you’ve reduced your risk for coronary artery disease but you may have increased your risk for some other disorder,” he says.

There is also a major practical problem, says O’Neill. You can’t know what SNPs an embryo will inherit until it forms, so you can’t work out risk in advance. But if you wait until this stage, it may be too late to edit the genome.

Oliynyk thinks the answer could be the use of synthetic genomes – rebuilding genomes from scratch and correcting disease-causing variants. This is not yet possible with large genomes like ours, but Oliynyk is confident it will be.

“It is a purely technological issue, and these are always solved,” he says. Michael Le Page ■

For more on gene editing, see page 14

THE US Army is taking wireless

recharging to new heights, by

using lasers to power small drones

in mid-air.

Small multicopters – flying vehicles

with several rotating blades – have

proven valuable to the military for

intelligence gathering. But they

are power-hungry, meaning that

their flying time is limited to half

an hour or less.

Now the US Army’s

Communications-Electronics Research,

Development and Engineering Center

based in Maryland is developing

a power beaming system with a

combination of lasers and efficient

photovoltaic cells.

The aim is to provide enough

power from 500 metres away to

keep a drone patrolling indefinitely

above a base, or flying over a convoy

for its entire route. The system works

by firing laser light at photovoltaic

cells on the drone, which then

converts the light into electricity.

“The major challenge we see is

thermal management,” says project

engineer William Rowley. Any energy

that is not converted to electricity

becomes heat, so there is a risk

of melting or burning the drone.

This problem is being overcome by

developing accurate beam control

and ensuring the excess heat can

dissipate.

The plan looks technically feasible,

according to David Anderson at the

University of Glasgow, UK. However,

proving its safety is another matter,

given the potential risks from the

high-energy beam, such as eye or

skin damage.

“The challenge is how you can

convince the regulatory authorities

that it is safe,” says Anderson.

“Specifically, you have to persuade

them that the laser will not miss

the drone energy collector panel

when charging.”

The team aims to demonstrate

a first working system in 2019.

David Hambling ■

DNA editing before birth may bring healthier lives

JAD

E A

LB

ER

T S

TU

DIO

/GE

TT

Y

For daily news stories, visit newscientist.com/news

“ Those treated would live two decades longer on average before developing a range of cancers”

Drone can fly indefinitely by laser power

Genome engineering could reduce disease risk in generations to come



NEWS & TECHNOLOGY

SUBTLE clues in how you type on a

keyboard may be able to reveal early

signs of Parkinson’s. The hope is that

this could help spot the disease before

pronounced hand tremors or serious

changes in the brain have occurred.

To test the approach, hundreds

of volunteers installed a program

on their computers that monitored

their typing over nine months.

Warwick Adams at Charles Sturt

University in Australia then whittled

the sample down to 76 individuals

who were of the appropriate age, not

taking medication, and who either

didn’t have Parkinson’s or whose

condition was of mild severity.

Adams wanted to see if the times

between key presses could be

accurately plotted against a sine

wave of 4-6 hertz – the frequency of

Parkinson’s hand tremors. If these

data points didn’t map well to such

a curve, that would be an indication

that no tremor was present.

Using this technique, the system

was able to correctly identify patients

who had mild Parkinson’s disease

tremor with 78 per cent accuracy

(bioArXiv, doi.org/ctjk).

“The endgame is to develop a

widely available screening test

for both GPs and individuals,” says

Adams, who has Parkinson’s himself,

but not tremors.

Early detection would in

theory allow doctors to prescribe

treatments that can inhibit the

progression of the disease. About

three-quarters of people with

Parkinson’s develop hand tremors.

Adams has previously developed a

method of detecting early Parkinson’s

disease by spotting changes in the

flow of someone’s typing. He thinks

combining the two methods will help

build a diagnostic tool.

However, one difficulty the system

will face is that mild tremors are most

pronounced when resting, not typing,

says Álvaro Sánchez Ferro at the HM

CINAC Comprehensive Neurosciences

Center in Spain. Chris Baraniuk ■

Your typing could reveal Parkinson’s

Leah Crane

THERE is a weird cold spot on Europa, and nobody knows what it is. The first full thermal map of Jupiter’s icy moon has thrown up a spot about 300 kilometres across that seems colder than its surroundings, and we don’t have enough data on the area to figure out why.

Samantha Trumbo at the California Institute of Technology and her colleagues used the Atacama Large Millimeter Array, a set of more than 60 radio telescopes in Chile, to measure the heat radiating from Europa’s surface in a set of four overlapping thermal images. It represents the first full temperature map of the icy moon.

“We weren’t so interested in cold spots, we were more interested in hot spots, because those could indicate geological activity,” says Trumbo. “But we saw this one cold spot repeated in two of the images.” The spot is only about 9°C colder than the surrounding areas, but it

is different enough to be surprising, she says (arxiv.org/ abs/1808.07111).

There are two main potential explanations for the cold spot: either it is emitting less heat than the rest of the surface, or it takes longer to warm up in Europa’s morning.

The first could happen if the ice there has a different composition to that in the surrounding area, making it harder for heat to travel through it. The second could be a result of a blockier, less grainy texture. A large block of ice would

take longer to warm up, much as an ice sculpture can last an entire afternoon but a bowl of ice cubes will melt within a few minutes.

“If this spot is real, I would expect it to be a large ice sheet, maybe younger than the rest of the surface because it hasn’t been broken up yet,” says

Jessica Noviello at Arizona State University. “On Europa, I would be interested in studying something young to see what this moon really looked like in its earlier state and how it changed over time.”

The model that Trumbo’s team used to spot this anomaly was partially based on limited data from the Galileo spacecraft on the area’s albedo, or reflectiveness. Because of that, Noviello and Julie Rathbun of the Planetary Science Institute in Arizona doubt that the cold spot is actually there. “I looked back over the Galileo data, and there is no good data on that area, so we have no idea what it looks like,” says Rathbun.

Despite the lack of data, Trumbo insists that there’s something odd going on. “It is possible that our albedoes are not 100 per cent correct – actually it’s likely,” she says. “But it would be strange if they were wrong significantly in only one location without that spot being somehow different.”

Figuring out exactly how it is different will have to wait for more data. “For now, you can imagine almost anything,” Trumbo says. ■

Mystery cold spot found on Europa

NA

SA

/JP

L-C

ALT

EC

H/S

ET

I IN

ST

ITU

TE

“ The cold spot might emit less heat than the rest of the surface or take longer to warm up in the morning”

Part of Jupiter’s icy moon Europa is even chillier than the rest


DAVID YARROW INTRODUCES THE NIKON FULL FRAME D850.

To launch the new Nikon D850, master wildlife photographer David Yarrow was given

the creative freedom to capture the image of his lifetime, shot on the D850. Thanks

to the powerful combination of the 45.7MP FX format back-side illuminated CMOS

sensor and the speed of 9*fps shooting, he could tell a story like never before.

With ISO 64 to 25600, 153-point AF, 8K time-lapse** and full frame 4K UHD video,

now you too can capture your masterpiece. David is passionate about wildlife

conservation, and is the ailiated photographer of the Tusk Trust Foundation.

To find out more about the D850, and David’s story, visit www.nikon.co.uk

*Requires the optional MB-D18 Multi-Power Battery Pack, EN-EL-18a/b battery, BL-5 battery cover and MH-26a charger. **Requires Interval Timer settings and 3rd party software.

I AM RELENTLESS



NEWS & TECHNOLOGY

Timothy Revell

DO COMPUTERS know what we are thinking? To find out, a team at the University of California, Berkeley, has created a set of gruelling tests that probe AI’s progress in understanding the world. None has passed the tests yet, but one got very close.

The tests examine theory of mind – the ability to reason about another’s beliefs – and are inspired by experiments in psychology. Each consists of a short paragraph describing a scenario involving people – for example, Sally hides a marble and then Anne moves it to a new location.

Passing the test revolves around identifying first and second-order beliefs. A first-order belief is working out what someone else thinks, answering a question like “where does Sally think the marble is?”, for example. A second-order belief is what someone thinks someone else is thinking, for example, “where does Anne think Sally thinks the marble is?”.

Children are normally able to correctly identify first-order beliefs by around age 3, but it isn’t until age 6 or 7 that they can do

the same for second-order beliefs.Aida Nematzadeh, who led the

work and is now at Google’s AI lab at DeepMind, and her colleagues generated 10,000 scenarios and associated questions that tested theory of mind via first and second-order beliefs. They then put them to four state-of-the-art AIs. None managed to achieve a passing score, which was set at 95 per cent. Most humans should be able to score 100 per cent.

The highest achiever was an AI called RelNet, produced by Adam Santoro and his colleagues at DeepMind, which scored 94.3 per cent. The other three AIs managed scores of between 82 and 94 per cent (arxiv.org/abs/1808.09352).

However, the results were fairly fickle. Inserting an unrelated sentence with no bearing on the tested situations was enough to bamboozle the AIs. All of them dropped their scores by between 5 and 20 per cent, suggesting they weren’t properly grasping the meaning of the text.

Though no AI has yet displayed theory of mind, they are improving at an impressive rate. Only two years ago, Facebook produced a series of tests that

would examine AI’s ability to answer questions about the world. None tested could handle the task at the time, but some can now pass with few mistakes.

A machine with theory of mind could prove useful, says Alan Wagner at Georgia Tech Research Institute in Atlanta. “An AI agent teaching assistant might be able to reason about a student’s false beliefs related to a course, for

example, that the final exam is next week when in fact it is tomorrow, and in doing so be better suited to help.”

Another example is self-driving cars, says Johannes Bjerva at the University of Copenhagen, Denmark. An AI-driven car with theory of mind might realise that the driver of another car hasn’t seen a person in the road, and honk its horn to warn them, he says.

However, even if an AI can pass these tests, it may still not have theory of mind, says Wagner. ■

AI takes ‘marble’ theory-of-mind test

EY

EE

M/A

LA

MY

ST

OC

K P

HO

TO

“ If we take action now, some coral reefs may still exist a hundred years in the future”

REPEATING an experiment 47 years

after it was originally carried out has

revealed some rare good news about

corals: some species appear to have

become significantly better at

surviving temperature increases.

In 1970, marine zoologist Steve

Coles collected three species of coral

from a reef in Kane‘ohe Bay, Hawaii.

When he put them in a chamber and

Some corals are beginning to beat the heat

gradually heated the water, he found

that they couldn’t tolerate increases

of 1 to 2°C. They started to bleach,

ejecting the colourful algae that live

within them. Without these, coral die.

Overall, no corals from one species

survived, and survival rates were 40

per cent and 5 per cent for the others.

But Coles, at the Hawaii Institute of

Marine Biology, got a different result

when he repeated the experiment

using the same species of coral from

the same area decades later. When

he raised temperatures by the same

amount, it took a few days longer for

the corals to begin bleaching, and more

than half survived (PeerJ, doi.org/cthn).

“That was a big surprise,” says Coles.

The finding is in line with anecdotal

observations from reefs that some

corals seem to be surviving bleaching.

Coles doesn’t know how they do it,

but other research suggests some

corals adapt to higher temperatures

by associating with species of algae

that are more tolerant of heat stress.

It isn't clear whether corals in

Hawaii are individually acclimatising

to rising temperatures, or whether

they have genetically evolved a heat

tolerance that they will pass onto

future generations, says Mikhail Matz

at the University of Texas at Austin.

Either way, it is good news, he says,

although genetic adaptation may

have more lasting benefits.

Coles doesn’t think the change will

be enough to counteract the effects

of global warming on coral. But it

suggests that, if we take action on

climate change now, some coral reefs

may still exist in a hundred years’

time, he says. Katarina Zimmer ■

Tracking marbles can test the ability to reason what others think–


All-seeingWe help pilots see the big picture where it counts. Whether helmet-mounted or head-up, our intuitive displays provide flight-critical information when and where it’s needed most.

To find more about our innovations,

visit us at New Scientist Live - stand no. 1711

baesystems.com/nsl2018Copyright © 2018 BAE Systems


Subscribe today

To subscribe visit newscientist.com/11380 or call 0330 333 9470 and quote 11380

Prices are for delivery in the UK only. International prices apply. Free book How to Be Human is only available with annual App + Web or Print + App + Web subscription purchases where delivery is in the United Kingdom or Euro area.

PRINT + APP + WEBWeekly magazine delivered to your door

+ full digital access to the app and web

Only £4.58 per week

(Print or digital only packages also available)

HOW TO BE HUMANTake a tour around the human body and brain

in the ultimate guide to your amazing existence.

Find witty essays and beautiful illustrations in

this 270 page hard back edition.

More ideas... more discoveries... and now even more value

+

“A beautifully produced book which

gives an excellent overview of just what

makes us tick”

SAVE 52% AND GET A FREE BOOK

WORTH £25

SUBSCRIPTION OFFER

“A beautifully produced book which

gives an excellent overview of just what

makes us tick”



NEWS & TECHNOLOGY

EVER felt like you are struggling to

think about too many things at once?

That might be because your brain’s

attention systems are full.

A brain scanning method that

shows how much energy nerve cells

are using has provided support for

the idea that we have a finite amount

of attention available. This offers an

explanation for the bizarre “invisible

gorilla” optical illusion, in which

people focus so much on one aspect

of a staged video that they fail to

see a person in a gorilla suit.

Nilli Lavie at University College

London (UCL) took advantage of a

new brain scanning method, called

broadband functional near infrared

spectroscopy, which was developed

as a way of measuring the brain’s

oxygen levels with a simple headset.

Another research group at UCL

has tweaked the technology so

that instead of oxygen, it measures

the activity of an enzyme inside

mitochondria, the tiny structures

that provide cells with energy. “We

are measuring the metabolism inside

the neuron,” says Lavie.

In her latest experiment,

participants did either an easy or hard

version of a visual task that involved

spotting certain shapes and colours on

a screen, while wearing the headset.

Half the time they were also shown a

flickering chequerboard pattern in the

periphery of their vision.

When the main task was easy, the

brain cells dealing with peripheral

vision raised their firing rates as the

pattern started flashing. When the

main task was difficult, the flashing

chequerboard pattern led to little

increase in neural activity. “You

suppress things you’re not attending

to,” says Lavie, who presented the

findings at a recent UCL Neuroscience

Symposium.

Jan de Fockert of Goldsmiths,

University of London, says other work

has also shown that demands on our

attention from one sense can affect

other senses too. Clare Wilson

Brains at full capacity stop noticing things

Inga Vesper

HIGH prams with canopies that shield a baby’s head could go some way towards reducing exposure to dangerous particle pollution.

By kitting out prams with air quality sensors and taking them for a stroll, a team at the University of Surrey, UK, is studying how much pollution babies are exposed to and the pram designs that are best at combating it.

The team has found that higher prams are better, because most particle pollution is concentrated in the first metre above road level. On average, children in prams breathe at a height of about 0.85 metres, meaning they are exposed to about 60 per cent more pollution than adults.

On top of this, particle pollution is more dangerous to infants than adults, says Jonathan Griggs at Queen Mary University of London, who was not involved in the study. Babies breathe faster than adults and they are more vulnerable to the effects of

pollution because the protective mechanisms in their lungs are not yet fully developed, he says.

When choosing the best pram for defending against pollution, the weather is also a factor. Hot summer air concentrates pollution close to the ground, making seat height particularly important. But when the air is cold, the heat from car exhausts whirls dangerous particles higher in the air, after which they descend. In these cases, prams with some kind of covering, such as a canopy or plastic bad-weather

cover, can help protect children from pollution falling down on them from above (Environment International, doi.org/cthc).

“There are very few existing studies to draw conclusive evidence on which pram design is best,” says Prashant Kumar, who led the research. So far he is only

able to identify broad things to look for in a pram, but his team are running further tests until the end of September, after which they plan to make more detailed recommendations.

In the future, it may be possible to purchase add-on air filter systems for prams. One currently in development is called Brizi. The device consists of a flat headrest with wings on either side of the baby’s head.

Air is sucked in on one side, cleaned, and blown out the other, creating a bubble of slightly higher air pressure, which keeps out particles.

Exposure to particle pollution damages lungs and can cause inflammation and long-term respiratory problems. According to the UK government’s Clean Air Strategy, around 340,000 life years are lost in the country every year due to pollution.

Designing better prams is only an interim solution to tackling pollution itself, says Griggs. “It’s certainly prudent not to stick your child next to an exhaust pipe, but in the end it is not about protecting babies by technology, but reducing emissions on roads,” he says.

Pram design can cut air pollution risk

WE

HN

ER

/PL

AIN

PIC

TU

RE

“Babies are more vulnerable to pollution than adults –they breathe faster and have less developed lungs”

Canopies can shield babies from swirling car exhaust particles



NEWS & TECHNOLOGY

Chelsea Whyte

CRISPR gene-editing has been used to improve muscle function in dogs with a condition similar to Duchenne muscular dystrophy (DMD) – and the technique might one day lead to a treatment for humans. The study represents the first use of CRISPR gene-editing in a living large animal.

People with DMD have a genetic mutation that makes them unable to produce dystrophin, a protein that maintains muscle structure and function. The condition can

result in heart or lung failure. In 2010, Richard Piercy at the

Royal Veterinary College in London and his colleagues identified the same mutation in a Cavalier King Charles spaniel that was brought into the veterinary hospital showing muscle weakness. They found relatives of that dog and bred them with beagles. Three of the resulting pups have now been used to test

a potential treatment for DMD.Today there is only one

approved DMD treatment to elevate dystrophin levels. In clinical trials, this drug treatment had modest effects: people taking it could produce dystrophin but only at about 0.4 per cent the levels seen in healthy individuals.

The gene-editing treatment has been able to restore up to 92 per cent of the dystrophin expression in the beagles’ heart tissue, 58 per cent in the diaphragm and 64 per cent in the biceps.

This method relies on CRISPR Cas9, a genome editing enzyme that cuts a cell’s DNA in a specific spot, guided there by RNA .

The team injected a virus carrying CRISPR and its RNA molecular guide into the skeletal muscle and heart tissue of two one-month old beagles with the DMD mutation. It is the first time CRISPR has been used in live animals of such a large size, says Eric Olson at the University of Texas Southwestern Medical Center. Six weeks later, they analysed the dogs’ muscles and sequenced their genomes before comparing them with a dog with the same mutation, and a healthy dog.

“We looked through the microscope and it was jaw-dropping,” says Olson. “Virtually all of the muscle fibres showed high levels of dystrophin underlying every membrane. We were exuberant.”

However, he says it is not known whether the treatment would have such dramatic effects in the human version of the condition (Science, doi.org/ctgz).

Melissa Spencer at the University of California, Los Angeles, says the results are a great first step towards a treatment, but she cautions that

they require more safety testing. “The Cas9 protein expresses

for a long time, so the immune system could attack it. We need a better assessment of the immune response, and we also need to be sure CRISPR isn’t cutting off-target,” Spencer says.

Recently, concerns have been raised that CRISPR does indeed cut off-target – snipping up DNA where it isn’t supposed to. Olson says they didn’t see evidence that this was happening in the dogs, and blood tests were normal after the treatment.

Piercy adds that he hopes the treatment could lead to a routine therapy for dogs with muscle disease, as well. ■

CRISPR helps dogs’ muscle disease

RV

C

“ Virtually all of the muscle fibres showed high levels of dystrophin. We were exuberant”

THE cleaner wrasse has become the

first fish to pass the mirror test – a

classic experiment used to gauge

self-awareness in animals.

Until now, only relatively intelligent

animals – such as apes and elephants –

have passed the test, which shows

whether an individual can recognise

itself. To see if fish may also be

self-aware, Masanori Kohda at Osaka

Fish passes mirror test for first time

City University, Japan, and his

colleagues put 10 wild cleaner wrasses

in individual tanks with a mirror.

During the first few days, seven

of the fish attacked their mirror

images. But these fish then began

to dash towards the mirror and

dance – unusual behaviours that

have never been observed before.

The team put a coloured gel onto

the heads of eight of these fish, in

positions that could be seen only

using the mirror. Seven of the fish

spent significantly more time in front

of the mirror in poses that let them

observe the mark on their head. Some

even tried to scrape it off (bioRxiv,

doi.org/cthm). According to the team,

this means cleaner wrasses are as

successful at recognising themselves

in a mirror as elephants.

However, Gordon Gallup of the

University at Albany, New York, who

invented the mirror test, is not

convinced. Cleaner wrasses eat

parasites living on other fish. These

wrasses probably mistook the marks

for parasites on the skin of other fish,

Gallup says. Yvaine Ye ■

See page 10 and page 28 for more on

self-awareness and intelligence

Some of these dogs have a genetic muscle condition – but which?

Cleaner wrasse are only about the

size of a human finger

HE

LM

UT

CO

RN

EL

I/A

LA

MY


DIAL UP THE DENIM

Friday 21 September is Jeans for Genes Day! Join Michael Dapaah and organise a

Jeans for Genes Day in your workplace to

help raise vital funds to support children

with life-altering genetic disorders.

Encourage everyone to wear jeans

and donate, and you will be doing

something amazing for children

with genetic disorders.

Sign up for your free fundraising pack jeansforgenes.org

Jeans for Genes ® and ™, © 2018 Genetic Disorders UK.

Registered Charity Number 1141583.



THE Arctic is in hot water, literally. Heat has been accumulating rapidly in a salty layer 50 metres down in a large part of the Arctic Ocean. Currently, it is capped by a less-dense layer of fresh water, but the fear is that winds could make this lid fall apart. If the two layers mix, this could melt all the seasonal sea ice above.

Mary-Louise Timmermans at Yale University and her colleagues

discovered the heat time bomb after analysing data on ice cover and sea temperature, heat content and saltiness at different depths over the past three decades in the Canadian basin, which is fed by waters from the North Chukchi Sea, north of the Bering Strait between Alaska and Siberia.

The team found that the heat content of the 100-metre-thick salty layer had doubled over this

time. The root cause is global warming, which has seen Arctic surface temperatures rise by 2°C from pre-industrial levels, leading to record-low sea ice coverage.

With sea ice retreating, heat absorption by surface waters has increased fivefold in 30 years, the team found. Strong winds push these newly warmed surface waters at the Arctic fringes down to the depths where they are now accumulating under the ice (Science Advances, doi.org/ctf4).

IN BRIEF

AG

AM

I PH

OT

O A

GE

NC

Y /

AL

AM

Y S

TO

CK

PH

OT

O

Wolves may have influenced when elk shed their antlers

EACH spring male elk lose their antlers so they can grow

back bigger and stronger to fight rivals for mates in

autumn. It turns out wolves may have helped shape the

evolution of this timing: if elk lose their antlers too soon,

their risk of ending up as wolf food rises. Too late and

they may fail to win a mate.

Matthew Metz at the University of Montana and

colleagues analysed 55 encounters between male elk

and wolves in Yellowstone National Park from 2004 to

2016. They found that elk that shed their antlers early

were also the most vulnerable to wolf attacks.

In 18 cases wolves attacked a lone male, and the

presence or lack of antlers made no difference. But the

remaining 37 encounters involved attacks on groups of

two or more male elk, and wolves targeted stags without

antlers. Groups containing at least one antler-less animal

were 10 times more likely to be attacked (Nature Ecology

& Evolution, DOI: 10.1038/s41559-018-0657-5).

The findings may also apply to related species.

Elk don’t have a choice about when they shed their

antlers – it is probably linked to testosterone levels –

but shedding early seems to carry long-term benefits for

a potential short-term but fatal cost.

“We suggest that wolves – formerly everywhere across

the northern hemisphere – have shaped the timing of

when elk… shed their antlers,” says Metz.

Warm-water time bomb threatens Arctic

Opioid blocks pain and addiction

A NEW opioid drug has been shown to stop monkeys feeling pain, without any apparent addictive or harmful side effects.

Opioids such as morphine stop pain, but can also be addictive. In the US alone, more than 46 people die daily from overdoses of prescription opioids.

Mei-Chuan Ko at Wake Forest University in North Carolina and his colleagues have found that a drug called AT-121 blocks pain by activating two types of opioid receptor in the brain. One is the mu opioid receptor, the pain-relieving receptor targeted by many opioids. The other is the nociceptin opioid receptor, which blocks the brain’s addiction-forming response, while also providing pain relief.

The drug was 100 times as good as morphine at reducing pain in monkeys. No addictive properties were seen (Science Translational Medicine, doi.org/ctf3).

Serengeti shaped by ancient herders

AFRICA’S Serengeti grasslands are far from pristine works of nature. In fact, their rich biodiversity may owe more to cowpats from livestock corralled overnight by nomadic herders millennia ago.

Such dung has long been known to provide hotspots of nutrients in otherwise barren grasslands, eventually enabling much richer ecosystems to develop. It was assumed that, on the Serengeti, these spots – called grassy glades – date back roughly 1000 years.

Fiona Marshall of Washington University in St Louis, Missouri, and her colleagues have shown they may be much older. The team sampled five sites in Kenya and found evidence of dung and richer soils dating back 3700 years (Nature, doi.org/gd3zfb).



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

A machine to split the electron

SURF’S up! Electrons riding a plasma

wave can be accelerated to high

energies, which may let us build

small particle accelerators to smash

them up and learn more about the

tiniest objects in the universe.

The world’s largest accelerator,

the Large Hadron Collider at the

CERN particle physics laboratory

near Geneva, Switzerland, smashes

protons by whizzing them around

a 27 kilometre ring, but that won’t

work for electrons – they have to

be accelerated in a straight line.

The Advanced Proton Driven

Plasma Wakefield Acceleration

Experiment, also at CERN, gets

round this by shooting hundreds of

billions of protons into a tube filled

with rubidium atoms that have been

stripped of their electrons, forming

a plasma. This results in waves in

the plasma, and when electrons

are injected into the tube,

the waves accelerate them.

The container used is just

10 metres long, and the electrons

at the end reached energies of

2 gigaelectronvolts (GeV) (Nature,

doi.org/gd3zfz).

Electrons are fundamental

particles, meaning we think they

don’t break down into anything

smaller. But we don’t know for

sure. To test that would require

smashing electrons at hundreds

of GeV, which could be done

using higher-energy protons.

Print with sound using honey as ink

PRINTERS that use sound waves may

one day let us build structures out of

honey droplets, or even print human

tissue without harming cells.

Regular inkjet printers are great

at controlling the placement and

size of ink droplets, but only work

for watery fluids. Daniele Foresti at

Harvard University and his colleagues

have come up with a way to print

droplets of viscous liquids.

Inkjet printers rely on streams of

liquid naturally separating into drops.

To make droplets from a viscous fluid,

that fluid has to be forcefully broken.

The team turned to sound waves,

which can exert a force on objects.

Their printer extrudes a droplet

from a nozzle and then fires sound

waves at it to make it fall to the

printing surface.

The sound is extremely loud,

but it is at a high frequency that

the human ear cannot detect.

The researchers tested the printer

using water, honey and a liquid mix

of gallium and indium metal. They

also tried an ink full of human cells to

confirm they wouldn’t be killed by the

sound (Science Advances, doi.org/

ctjq). “With the cells, you could do

tissue engineering,” says Foresti.

AN ARTIFICIAL intelligence system called Revolver is unveiling the evolutionary tricks cancers use to spread and defy treatment. It should allow doctors to more accurately identify what stage cancers have reached, what they will do next and how to stop them.

We can treat cancer if we intervene early enough, says Andrea Sottoriva of the Institute of Cancer Research in London, whose team is developing Revolver. “The key is, can you stay one step ahead of the disease?” he says.

Revolver helped Sottoriva’s team unmask key evolutionary steps in cancers. It uses data from patients to create a genetic “family tree” tracking how cancer evolves, and identifies the series of mutations that most often lead to cancer. Existing analyses, often relying on samples from one patient, can struggle to distinguish important mutations from harmless ones.

Revolver instead analysed mutation data from 178 patients, covering 768 tumour samples and four types of cancer – bowel, lung,

breast and kidney. This made key evolutionary steps stand out better. Three key gene mutations are known to be crucial for benign colon polyps to turn cancerous, for example, but have not been seen together in a single patient.

Despite this, Revolver identified the three mutations as the key ones when tested on gene profiles from 95 colorectal cancer patients. It also correctly identified key mutations already known to drive evolution of lung, breast and kidney cancers (Nature Methods, doi.org/cthk).

AI could help doctors stay one step ahead of cancer

MS drug halves loss of brain tissue

AN EXPERIMENTAL drug for the most severe forms of multiple sclerosis has slowed brain shrinkage by nearly 50 per cent.

Loss of brain tissue is a marker of disease progression in primary and secondary progressive MS. In these forms of the disease, the ongoing breakdown of the protective myelin that surrounds nerve fibres in the brain leads to slower nerve signals, which can ultimately result in muscle weakness and problems with balance and vision.

Robert Fox at the Cleveland Clinic in Ohio led a phase II clinical trial of a drug called ibudilast, which inhibits proteins that can result in central nervous system inflammation.

The trial involved 255 people from the US, with 126 receiving a placebo instead of the drug. Each took up to 10 capsules per day for 22 months and had brain scans every six months to gauge the volume of brain tissue.

The team found that, on average, ibudilast slowed brain shrinkage by 48 per cent compared with placebo, with those given the drug losing 2.5 millilitres less brain matter (New England Journal of Medicine, doi.org/ctf2).

CE

RN

DA

NIE

LE

FO

RE

ST

I, JE

NN

IFE

R A

. L

EW

IS,

HA

RV

AR

D U

NIV

ER

SIT

Y

IN BRIEF


B O O K Y O U R T I C K E T S N O W

newscientistlive.com

The world’s most exciting festival of ideas and discovery

20 – 23 Sept 2018 | ExCeL London

CUSTOMISE MY COCKPIT!It’s 2040 and you’re piloting Britain’s newest fighter

aircraft. At Mach 1.2, you ask the AI assistant to plot

a course and hand it control of the plane. You switch

to night mode and look down to see an image of the

terrain below created from multiple sensors on the

plane’s skin...

Rewind to 2018 and engineers are working on a

sleek, stealthy combat aircraft that isn't due to fly

for many years. Yet its systems are not so far from

reality – they will be based on technologies being

developed by scientists at BAE Systems and the

University of Birmingham.

For pilots the changes will be profound. AI will

take on an increasing range of tasks, for example.

But the biggest change is likely to be in the look

and feel of the cockpit. “What we’re trying to do

is to augment the human,” says Nick Colosimo,

a technology strategist at BAE Systems.

Pilots today are largely stuck with a massive

array of instruments and controls. By making them

virtual, the cockpit can be de-cluttered so pilots see

only things that are relevant to their mission. They

can also personalise what they see, like customising

the home screen on their mobiles.

Head-up displays will be transformed to

have a very wide field of view in full-colour and

high-resolution. These will offer a wide range of

functions, such as adding markers to significant

locations that appear to be outside the cockpit.

Pilots’ brain waves and blood oxygen will be

monitored to detect when they are overloaded or

losing alertness. In such cases, the cockpit could

automatically de-clutter to focus attention. The

flight suit could also squeeze the pilots’ legs to

prevent blood flowing from the brain.

At New Scientist Live on Saturday 22 September,

Colosimo will discuss these developments with Bob

Stone, director of the human interface technologies

team at the University of Birmingham. Some he

hopes will transfer to everyday life. For example,

high g forces can make pilots’ arms feel

heavy while vibrations give them the

shakes. So researchers at BAE Systems

are testing hands-free ways to

communicate with the plane. One option

is eye-tracking, which Colosimo hopes

could eventually be transferred to the health

sector. “We hope we can spin back some

of this work,” he says.

TECHNOLOGYZONE SPONSOR

A D V E R T O R I A L



HYDROGEN-POWERED cars have had a bumpy ride. Back in 2003, they were touted as “one of the most encouraging, innovative technologies of our era” by US president at the time George W. Bush. Then the Tesla revolution came along and they were left in the dust by their battery-driven electric rivals.

Now, there are signs of a comeback. A recent survey of more than 900 global automotive executives by consulting firm KPMG found that 52 per cent rated hydrogen fuel cell vehicles as a leading industry trend. Japan has announced plans to put 40,000 hydrogen vehicles on the road in the next five years, and South

Korea 16,000. Germany wants to have 400 refuelling stations for hydrogen vehicles by 2025 and California has already opened 35.

This renewed push has its sceptics. Tesla chief Elon Musk, for example, has dismissed hydrogen cars as being “extremely silly”. But Joan Ogden at the University of California, Davis, sees a future in which hydrogen and electric vehicles play complementary roles. “There are arguments for having both,” she says.

Like electric cars, hydrogen vehicles produce zero pollutants and carbon emissions, so they don’t damage our health or the climate. The main difference is that hydrogen cars use a fuel cell

instead of a battery to power an electric motor. Hydrogen is stored in a tank and fed into the fuel cell, where its chemical energy is converted into electrical energy (see diagram, above right).

Hydrogen cars are finally becoming commercially viable

because fuel cells have become smaller and lighter, says Matthew Macleod at Toyota, which began selling the Mirai, one of the first mass-market hydrogen cars, in 2014 for $60,000. Honda and

Hyundai have competing models, and Mercedes-Benz plans to launch one next year.

We are also figuring out better ways to transport and store hydrogen, says Michael Dolan at Australia’s national science organisation, the CSIRO. Last month, his team showed that hydrogen gas can be converted to liquid ammonia for transportation, then converted back using a membrane made from the metal vanadium. Liquid ammonia takes up less space and is less flammable than hydrogen gas, making it easier to ship to refuelling stations.

The ability to rapidly refuel is one of the main advantages hydrogen vehicles have over their electric counterparts, says Macleod. Filling up a hydrogen car takes about the same time as filling a petrol one, rather than the hours it typically takes to recharge

INSIGHT HYDROGEN CARS

Gassed up and ready to goVehicles that run on hydrogen have been dismissed by the likes of Elon Musk, but they’re making a comeback, says Alice Klein

GE

TT

Y

The Toyota Mirai is one of the first mass-market hydrogen cars

“Hydrogen vehicles produce zero emissions, so don’t damage our health or the climate”



an electric car’s battery. You can also go further on a full tank of hydrogen – about 500 kilometres, compared with 300 kilometres for a standard fully charged battery (see table, below).

But although hydrogen reacts cleanly – the only thing coming out of the exhaust pipe is water – hydrogen vehicles are more energy-intensive than electric ones if you factor in fuel production and transport, says Jake Whitehead at the University of Queensland, Australia.

At the moment, most hydrogen is extracted from natural gas – a fossil fuel. “Green” hydrogen can be made by splitting water using solar or wind power, but this involves multiple steps, each using energy along the way. In contrast, a single energy step is required to directly recharge a car battery at home.

Clean fuel?

If you account for this complete energy cycle, Whitehead’s modelling shows that hydrogen vehicles require between 80 and 100 kilowatt-hours of electricity to travel 100 kilometres, compared with about 20 kilowatt-hours to travel the same distance in a battery vehicle. This is the main charge levelled by Musk at hydrogen cars. “[The efficiency is] terrible, so why would you do that? It make no sense,” he told reporters at the Automotive News World Congress in Detroit in 2015.

Hydrogen fuel is also more expensive than petrol. Hydrogen cars currently cost about 13 cents per kilometre to run, compared with 8 cents per kilometre for petrol cars. However, some projections suggest that the costs will become equivalent by 2025 as the technology to produce hydrogen becomes cheaper.

At the moment, there are only about 6000 hydrogen vehicles on the road globally, compared with 2 million electric vehicles. But Ogden says that hydrogen vehicles may end up becoming

more popular among certain drivers. “If you’re only using your car for short commutes or to get around the city, battery cars can handle all your needs,” she says. “But if you want a big car that you can take on long drives in the mountains on a whim, a hydrogen fuel cell car might be better.”

The shorter refuelling time and longer range of hydrogen fuel cells also make them appealing for taxis, buses and long-haul trucks, says Dolan. “These vehicles can’t afford to be stopping for hours at a time to recharge,” he says.

Hydrogen fuel cells are already finding applications in these heavy-use vehicles. Japan will showcase 100 hydrogen buses at the 2020 Tokyo Olympics, and South Korea plans to introduce 1000 hydrogen buses by 2022. A fleet of 180 hydrogen taxis, private-hire and police cars is being trialled in London, Paris and Brussels, and retailer Amazon has recently invested in hydrogen-powered forklifts for its warehouses. US manufacturer Nikola Motors, meanwhile, says it has received 11,000 pre-orders

for its hydrogen fuel cell truck.Japan and South Korea are

leading this push because they want to embrace zero-emissions technology, but their combination of small land masses and large populations means they don’t have enough solar, wind or other renewable energy to support large numbers of battery electric vehicles, says Dolan.

They can’t import renewable energy itself, but they can import hydrogen made from renewable energy in other countries. Australia, for example, could use its abundant solar energy to split water and export hydrogen to these countries, says Dolan. “You can see hydrogen basically as a carrier for renewable energy.”

Many people feel jittery about hydrogen because of its connection with hydrogen bombs and the 1937 Hindenburg disaster, in which a hydrogen-filled airship spectacularly caught fire, killing 36 people. But the hydrogen tanks used in modern fuel cell vehicles are made from multiple layers of resin, carbon fibre and fibreglass that keep the flammable gas safely contained. Tests show they

can even survive being shot at or set on fire. New ways of transporting hydrogen – like in the form of ammonia – will also make its deployment safer, says Macleod.

The most probable future scenario is that we will have a mix of vehicles run by batteries, hydrogen and petrol, each performing different roles, says Ogden. “There are proponents of the different technologies saying it’s all going to be all hydrogen or all batteries, but auto-makers are putting their money on both,”

she says. According to the KPMG survey, car-makers are predicting an even four-way split between electric, hydrogen, petrol and hybrid vehicles by 2040.

The final mix will depend on the willingness of governments and industry to invest in hydrogen infrastructure – for example, by building refuelling stations and introducing hydrogen buses – as well as consumer enthusiasm for hydrogen cars. But whether it ends up being hydrogen or battery power that wins the bigger share, any dent in the dominance of petrol vehicles is likely to be a good thing. With less emitted carbon warming our globe, less toxic exhaust fumes choking our lungs and less smog staining our skylines, we will all be better off. ■

“There are only about 6000 hydrogen vehicles on the road globally, versus 2 million electric vehicles”

For daily news stories, visit newscientist.com/news

A chemical reaction between oxygen and hydrogen generates electricity, which is fed to the car’s battery and motor. Water is the only by-product, leading to clean emission

BatteryPower

generation

Motor

High-pressure hydrogen tank

H2O2

Fuel cell stack

Water outAir in (oxygen)

Hydrogen in

SOURCE: TOYOTA

Car type Petrol Battery Hydrogen electric fuel cell Emissions Carbon dioxide, None Water

carbon monoxide,

NOx gases etc.

Typical refuel/ 3-5 minutes 8 hours 3-5 minutes

recharge time

Typical range 400 kilometres 300 kilometres 500 kilometres

Typical 8 cents/ 3 cents/ 13 cents/

running cost kilometre kilometre kilometre



COMMENT

The US plan to build a habitable station orbiting the moon is the worst idea of the new space age, says Robert Zubrin

BEFORE the recent Mars Society convention, I was asked what I thought of the US plan to send astronauts to the moon. No doubt I was expected to explain why the Red Planet is a more suitable goal, but I said this was about much more than the moon versus Mars.

I am prepared to make the case for prioritising Mars, though. Once warm and wet, it may have evolved life, and if we can find evidence of it, we could learn a lot about the possible prevalence and diversity of life in the cosmos.

Taking on Mars would inspire millions of young people into science. It is also the closest planet with the resources for human settlement. In short, Mars is where the science is, where the challenge is and where the future is. It should be the goal.

Unfortunately, that argument assumes that those making US space policy think it is important

for NASA’s human space flight programme to have any goal at all. This is far from evident. While the Trump administration says that it is setting its sights on a return to the moon, its actions do not lend credence to such claims.

If it intended to put people on the moon again, it would fund the development of a lunar lander. Instead it is funding the Lunar Orbit Platform-Gateway, a costly boondoggle that serves no useful purpose. US Vice President Mike Pence talks of it as a done deal.

What he fails to add is that we don’t need a lunar-orbiting base to go to the moon, or to Mars, or to go anywhere. Not only that, crewed trips to anywhere beyond Earth orbit would be designed to use the gateway as a staging post, adding to fuel requirements and decreasing the load they can carry, which is why I call it the Lunar Orbit Tollbooth instead.

Sheer lunacy

If they value facts, Americans can elect a scientist, says Shaughnessy Naughton

THE battle for political power in the US is heating up. The two main parties are stepping up pleas for support in this autumn’s midterm election, which will decide who controls Congress.

That’s nothing unusual. But November’s vote does offer something the electorate hasn’t seen before: a dedicated push to

get candidates with science backgrounds on the ballot. Anti-science attitudes in US politics are well-documented. For those enraged by them, help is at hand. I started 314 Action in 2016 to recruit, train and support scientists running for office, and we’ve been laying the groundwork to bring evidence-based policy to

the halls of power ever since. I founded this organisation in part because I know how hard it is to be a candidate with a STEM background – I was one myself. I’m a chemist by training, and when I ran for Congress in 2014, I realised that if you aren’t a lawyer or a career politician, it can be hard to break into politics.

Take, for example, the simple barrier of entry for scientists in the middle of their careers. Unlike lawyers (who are often

encouraged by their firms to run), taking a year off to campaign can spell the end of a scientist’s career. Our organisation acts as a support system and siren call for a community that has long shied away from politics.

The response has been promising. An unprecedented number of scientists ditched lab coats for suits and launched campaigns. While I neither expect nor desire every seat of Congress to be held by persons with STEM backgrounds, 2018 is a great chance to bolster the scientific community’s representation there. Currently, there is one physicist (Representative Bill

“There are more talk radio hosts in Congress than there are physicists and chemists”

A vote for reason



Clare Wilson

ALARMING headlines suggest one

in four teenage girls in the UK are

self-harming, motivated by sexist

stereotypes and pressures to look

good in a selfie society. The truth may

not be as bleak as it first appears.

These stories come from a report

by UK charity The Children’s Society,

based on an ongoing survey of 11,000

children aged 14, called the Millennium

Cohort Study. Among the girls, 22 per

cent said they had self-harmed.

For boys it was 9 per cent.

But while the term self-harm

conjures images of teenagers cutting

themselves, that may, thankfully,

be only the most extreme end of

a broader spectrum. In this survey,

participants were merely asked if

they had “hurt themselves on

purpose in any way”.

Some could have answered yes

for things like punching a wall in

frustration or deliberately getting

falling-down drunk. Others could have

thought the question included mental

hurt – such as spending a miserable

evening stalking an ex on social media.

They needed to have done something

like that just once in the past year

for it to count.

Such self-destructive behaviour

would naturally be of concern to

parents, but wouldn’t be that unusual

for teenagers. Max Davie, a health

promotion officer for the UK’s Royal

College of Paediatrics and Child Health,

does believe that self-harm among

teens is somewhat on the rise –

but thinks the question in this survey

was not specific enough to reveal its

real prevalence.

The latest headlines join an ongoing

narrative about a mental health crisis

in today’s youth. Some blame cutbacks

in social services, while others point

to a loosening of sexual norms putting

teens at risk. For those wary of new

technologies, it is social media or the

latest popular computer games.

But such reports also deserve

some scepticism. Claims of soaring

rates of depression are usually based

on surveys with very loose, non-

medical criteria. Teenagers have

always been sad or anxious from time

to time. Thankfully, clinical depression

is still rare in this age group.

In fact, a different and regularly

repeated survey has found no change

in 11-to-15-year-olds’ happiness with

life as a whole between 1995 and

2016. Nor did their satisfaction with

their appearance change, which makes

it odd to blame the selfie culture for

the apparent self-harm epidemic.

This survey, called Understanding

Society, even found a boost in

happiness with family and schoolwork

over that period. These more

optimistic findings were also in

the latest Children’s Society report,

but were buried at the bottom of

their press release.

Davie thinks the rise in self-harm

may not be due to a rise in

unhappiness, but simply that this age

group now sees self-harm as a more

culturally acceptable way to express

anguish. “It may be that previously

people didn’t know that this was

something you could do. If people

are talking about something and

normalising it, it’s probably more

likely that their peers will do it.”

If that is the case, it is all the more

reason not to make self-harm seem

more common than it really is. ■

Need a listening ear? UK Samaritans:

116123 (samaritans.org). Visit bit.ly/

SuicideHelplines for hotlines and

websites for other countries.

Are modern teens hurting or happy?

ANALYSIS Self-harm

SH

ES

TO

CK

/GE

TT

Y

“ The latest headlines join an ongoing narrative about a mental health crisis in today’s youth”

For more opinion articles, visit newscientist.com/opinion

Yet the problem with the project is bigger than the waste of time and money and the harmful distortions imposed on other missions. The deeper problem is the form of thinking it represents.

NASA’s astronomy and robotic exploration programmes have achieved epic accomplishments because they are purpose-driven. In contrast, since Apollo ended, NASA’s human space flight work has been purpose-free. As a result, accomplishments have been few. The science programmes spend money to do things. The human space flight programme is doing things to spend money.

The situation is ironic. With the success of the Falcon Heavy rocket that could send crew to the moon and Mars, the US could be poised for a deep space breakthrough.

The Lunar Orbit Tollbooth cash, if spent on developing landers and ascent vehicles, could enable a return to the lunar surface within four years and human missions to Mars in eight. What is lacking is intelligent direction. We will never get to Mars if we allow our human space flight programme to be run as a random walk.

Robert Zubrin, an astronautical

engineer, is president of the Mars

Society, which advocates for a human

mission to the Red Planet

Foster) in Congress. There are more than 200 lawyers. There are more talk radio hosts in Congress than physicists and chemists.

The time for signing polite letters and waiting to be tapped for an advisory role is over. Scientists need to get involved in electoral politics.

Voters want governance based in facts and evidence, and who better to lead that charge than those who have spent their careers in a role where there is no room for “alternative facts”. ■

Shaughnessy Naughton is founder

of 314 Action, which seeks to get

scientists into elected office in the US


APERTURE




Eye to eyeNO NEED to fear this hairy monster. This

poplar hawkmoth couldn’t even try to bite you:

it has no functioning mouthparts, and will

never be able to eat.

These moths (Laothoe populi) are found all

over Europe, and can reach the size of a small

bat. Unlike other moths, they have no proboscis

protruding from their head, so are unable to sip

nectar from flowers.

Instead, these adults rely solely on body

fat they stored for energy when they were

caterpillars. This keeps them going for just three

or four weeks, meaning the race is on to find a

partner and mate.

The large insects use pheromones to find each

other. This moth is a male, and will use his yellow

antennae to search for scent-emitting females in

the night. The females send their signals and wait.

They are so weighed down by eggs that flying is

too strenuous.

If they mate successfully, the eggs are laid and

more than 100 pale green caterpillars will emerge

a week later. Before winter arrives, these bulk up

on the food that gives their species its common

name – the leaves of poplar trees.

“I wouldn’t have stood a chance had this

individual been flying,” says photographer Alex

Hyde of this close-up. He snapped this hawkmoth

as it rested in Derbyshire, UK, early one summer

morning. “It is humbling to remember that we

are surrounded by a multitude of fascinating

creatures every day, most of which are too small

for us to give a second look to as we charge

through our busy lives,” Hyde says. Yvaine Ye

Photographer

Alex Hyde

Naturepl.com


JOIN US AT THE WORLD’S G

Over 120 talk

THE MANY WORLDS OF QUANTUM MECHANICS • THE NATURE OGUT HEALTH • GENOME EDITING • EXPLORING CONSCIOU

FUSION FUTURE • GRAVITATIONAL WAVES • NEUT

Book now at newscientistlive.com/dps

COSMOS ZONE SPONSOR

MAIN STAGE SPONSOR

EARTH ZONE SPONSOR

Everyone had a brilliant time – thought-provoking

and huge fun


REATEST SCIENCE FESTIVAL

s including …

OF TIME • HOW TO LOSE WEIGHT, FIND LOVE AND LIVE FOREVERUSNESS USING PSYCHEDELICS • ARTIFICIAL INTELLIGENCETRINOS • WHAT SHOULD WE DO ABOUT PLASTIC?

20 -23 September, ExCel London


HUMANSZONE SPONSOR

newscilive

newscientistlive

#nslive

@newscilive



LOOK into a mirror and you may see pimples, wrinkles or unruly facial hair, but beneath the superficial lies something

far more interesting. Every time you lock eyes with your reflection, you know exactly who is looking back at you. The sense of self is unmistakable. It is so much a part of being human that we often fail to notice it. Yet self-awareness is one of the biggest mysteries of the mind. How did it arise and what is it for?

Looking at other animals suggests we are not alone in being able to recognise ourselves in a mirror. Admittedly, it’s a short list of species that seem capable of this feat, but it hints at a possible explanation. Self-awareness may have evolved in only the brightest animals with the biggest brains. If so, it represents the peak of mental complexity – the highest form of consciousness.

However, some people have started to question this idea. Now, an extraordinary finding lends weight to their scepticism: one monkey species that was previously deemed unable to recognise itself in a mirror can easily learn to do so. This isn’t simply another name to add to the echelons of the self-aware. The discovery suggests we need to fundamentally rethink our ideas about mirrors and minds.

The hunt for self-awareness among non-

humans has been going on for decades. In the most widely used test – the so-called face-mark test – researchers stealthily apply a spot of odourless dye to an animal’s forehead or cheek and then observe its reaction when it is in front of a mirror. The underlying premise is that those with a firm sense of self can acknowledge their reflection and attempt to scrub off the dye.

Most of the animals that have passed this test are considered to be intelligent. They include chimps, bonobos, orangutans, Asian elephants and Eurasian magpies (a member of the notoriously clever corvid family). Killer whales and bottlenose dolphins also seem to recognise themselves in a mirror, although their anatomy means they can’t remove a face mark. This apparent correlation with smarts means that self-awareness has become a sort of proxy for mental complexity. But there are some puzzling evolutionary gaps. Gorillas, for instance, usually fail the test – with the notable exception of the recently deceased Koko – yet our more distant primate relatives, the orangutans, pass it. Also, the self-aware elite contains some bizarre anomalies such as pigeons, manta rays, ants and even a robot.

Some of these findings – particularly with ants and pigeons – are contested.

The why of me

Is having a sense of self really the hallmark of a sophisticated brain or simply an accident of evolution? Soia Deleniv investigates

>



RE

ILIK

A L

AN

DE

N/P

LA

INP

ICT

UR

E

COVER STORY



Researchers have tried to explain away others, arguing, for example, that gorillas have mentally regressed since their split from the other ape lineages because they face fewer pressures in their environment. But the recent discovery in monkeys is harder to dismiss.

Last year, Liangtang Chang and colleagues at the Shanghai Institutes for Biological Sciences, China, released video footage of a small group of rhesus macaques interacting with a mirror. It shows the monkeys contorting their bodies, tugging at their facial hair, inspecting their fingertips and making flashy displays of their genitals, all the while keeping their eyes on their reflections. They are captivated, leaving little doubt they recognise themselves. Yet, rhesus macaques have consistently failed the mirror test. And just a few weeks earlier, the ones studied by Chang’s team had shown no signs that they understood their reflections. What changed?

In fact, there is anecdotal evidence of macaques in the lab showing a sudden interest in mirrors after being fitted with bulky neural recording devices that protrude from their heads. Chang’s team wondered whether the monkeys genuinely lacked self-awareness, or whether they were being held back by a lack of coordination – an inability to link what they saw with internal signals generated by their muscle movements. To test this, they taught the monkeys to link vision and movement by giving them a food reward for touching a projected laser dot. At first, the researchers shone the laser where the monkeys could easily see it, then gradually worked up to shining it in places only visible in the mirror. Fast-forward a few weeks of practice, and they passed the face-mark test with flying colours.

At the least, this indicates that the way we test for self-awareness is flawed (see “Mirror, mirror”, right). That, in turn, raises the possibility that self-awareness is much more widespread than we think. So, what do we know about the evolution of this prized trait?

Levels of consciousness

Many psychologists and anthropologists hold that there is a hierarchy of consciousness that corresponds with increasing brain complexity. At its base is the minimal consciousness attributed to animals with simple nervous systems. These minds are thought to be permanently adrift in a sea of raw sensory experiences, tossed around between perceptions such as colour, hunger, warmth and fear, with little awareness of their meaning. Few minds are sophisticated enough

to experience the world differently – through an introspective lens. Even then, they may have a limited sense of self. Only at the peak of mental complexity do we find minds able to construct a lifelong narrative of experiences centred around an abstract concept of “self” – these are the elite.

What is the evidence for this hierarchy? After all, mental complexity is a slippery concept and, besides, none of us has insight into even the mind of another human, let alone a bat or a beetle. Well, there’s no question that some brains are much bigger and more structurally complicated than others. This disparity is mainly the result of the differing evolutionary demands that animals must meet to survive. For example, the nervous system of a sedentary, filter-feeding oyster consists of just two cell clusters. These allow it to do exactly what an oyster needs to do – control its digestion, and transmit signals from light-sensing tentacles to the muscle that snaps it shut when a predator looms. Meanwhile, at the other end of the spectrum, there is one particular demand that seems to have led to the evolution of complex brains and could also have created the conditions for a sense of self to arise. That challenge is dealing with the minds of others – be they prey, competitors or other members of your social group.

According to the social brain hypothesis, developed by Robin Dunbar at the University of Oxford, life in tight-knit communities is especially challenging because close relationships hinge on being able to understand what is going on in another individual’s mind. To achieve this, brains needed to evolve from being simply things that experience sensations and thoughts to becoming their observer. To do this, they needed to build a model of a mind, according to neuroscientist Michael Graziano at Princeton University. And once the biological machinery for such model-building evolved, it could be used to represent not only the minds of others, but also one’s own mind.

A model – be it for mind reading, weather forecasting or whatever – usually starts with some assumptions about the factors that contribute to the system in question and their relative importance. It then runs a simulation and, depending on how much the result diverges from physical observations, modifies the assumptions. The model thus acquires an accurate representation of the forces at work, allowing it to make reasonable predictions about the future. “The brain is a model-builder,” says Graziano. “You can’t move your arm properly if your motor system doesn’t JO

E R

AE

DL

E/N

EW

SM

AK

ER

S

The ability to recognise oneself in

a mirror is generally taken to be an

indicator of self-awareness, but that

idea is being challenged. For a start,

developmental psychologists argue

that it doesn’t necessarily reveal an

awareness of self that extends

beyond the here and now.

Experiments show that children can

acknowledge themselves in a mirror

at the age of 3, yet cannot recognise

themselves in videos taken a few

months earlier. They will struggle

with the idea of existing in the past

for another year or two.

It is even less clear what it means

for a non-human animal to recognise

itself in a mirror. Only a handful of

species seem capable of the task.

The majority are either our primate

relatives or animals with complex

social lives, like us. So, rather than

reflecting mental complexity, it could

simply indicate that their minds have

evolved to face similar challenges

to our own. Besides, the discovery

that animals can learn to pass the

mirror self-recognition test hints

that there could be many species

with undetected self-awareness

(see main story).

MIRROR, MIRROR



know where it is, can’t predict where it will be in the next few seconds, and can’t run simulations about what will happen if it sends out this or that command to the muscles.” And, he argues, the brain uses exactly the same strategy to model minds so that it can interact socially. If he is correct, then what you consciously experience is the simulation.

By extension, self-awareness is the conscious state of running that simulation on your own mind. Graziano believes we have no reason to put it on a pedestal. “Self-awareness is not higher-order, or intrinsically more complicated, than consciousness,” he says. “It is another example of consciousness.” A mind is just an object that some brains can model, and so become aware of. Moreover, it is hard to establish whether this ability is associated with uniquely complex biological machinery. After all, we are still struggling to pin down what consciousness looks like in the brain.

Most researchers agree that the brain operates at least partly by generating simulations. However, many disagree that consciousness is a functional piece of the modelling machinery. Instead, a widely held view sees it as the unintended by-product of information rushing through the closed loop of connections that is the brain. Consciousness can’t help existing despite serving no particular purpose, just like the noise emitted by a running engine, which has no bearing on the workings of the engine itself. By this way of thinking, self-awareness isn’t even a simulation; it is just a hall of mirrors.

Such emergent phenomena are common in nature. They give the mesmerising impression of complexity and intentionality, despite stemming from a system whose components operate with no regard for the phenomenon itself. One notable example is the collective behaviour of flocks of birds, which can be modelled using individuals driven by just two opposing forces – an instinct to follow their nearest few neighbours, and to back off if they get too close. Apparent complexity emerges even in Petri-dish-bound bacterial colonies, where individual bacteria automatically respond to chemical signals secreted by their neighbours to regulate their proximity.

The structure that emerges has no agency or purpose – it is purely an indicator of the forces at work in each individual.

Similarly, self awareness may be an apparently complex phenomenon that emerges from the brain. However, unlike with birds or bacteria, a mind cannot observe its individual components. It can only glean the echo of billions of neurons responding to each other with electrical signals. The flow of signals is dynamic, rushing along a different set of connections every moment. But some paths are more well trodden than others. In humans, the predominant connections seem

to be those used to contemplate the minds of others – the same connections used to contemplate ourselves. What emerges from this is a pattern that seems constant. To you, that is your sense of self, confined inside the Petri dish of your brain.

In other animals, the well-trodden paths in the brain will be different. In bats, for example, it might be those transmitting information from the echolocation clicks used to construct a 3D model of the world. There will be a huge diversity of emergent mental patterns that serve the various survival needs of different species. Looked at this way, there is no clear hierarchy of consciousness corresponding to mental complexity.

Consider the octopus

In fact, some of nature’s most sophisticated minds probably lack a sense of self as we know it. In mammals, those with bigger social groups generally have bigger brains, implying that a sense of self goes hand in hand with intelligence. But some other animals seem to have evolved to be highly intelligent without having had to understand the minds of others.

Take cephalopods – a group of marine animals that includes cuttlefish and octopuses. Having spent years collaborating with marine biologists, philosopher of science Peter Godfrey-Smith at the University of Sydney believes that the particularly large brain of the common octopus is shaped mainly by the unique demands on a soft-bodied animal inhabiting an environment dominated by vertebrates. This challenge might have triggered the evolution of a bodily self-awareness akin to that of primates, but Godfrey-Smith sees a clear distinction between the two. “When one watches an octopus squeeze through a tiny space, it certainly looks [different],” he says. Either way, we can rest assured that if an octopus has a sense of self, it will have very little in common with the “self” that inhabits our brains. It is even less likely to be something we can measure with a mirror.

Indeed, all this makes clear that the best we can hope for with mirrors is an imperfect glimpse into minds like our own. What’s more, if we proceed under the assumption that such minds are the true pinnacles of complexity, then we will miss out on the most beautiful thing about minds – that they are biological machines for adaptation, with contents that can be sophisticated in so many ways.

Sofia Deleniv is a doctoral student at the University

of Oxford

Smart animals like chimps and dolphins can recognise themselves in a mirror, but have they led us up the garden path?

JAM

ES

BA

LO

G /

AU

RO

RA

PH

OT

OS

“ Perhaps self-awareness isn’t even a simulation but just a hall of mirrors”



FOR the time being, Cape Town has dodged a bullet. After months of unrelenting drought, the recent winter rains have

begun to refill its parched dams. That doesn’t mean things are easy. City residents are still limited to using 50 litres of water a day, scarcely enough to half-fill a bath. But at least so-called day zero, when the taps run dry and residents have to wait in line to collect survival rations of water, has been averted.

The South African city is an extreme example, but it is far from the only place facing a severe water shortage. To slake that thirst, many cities are turning to the ocean, a seemingly inexhaustible supply of water. They are doing this through desalination, a water purification technology that has been around for decades. Cape Town is bringing a

couple of desalination plants online in a hurry and many others are being built elsewhere. As they spring up, however, attention is focusing on what they leave behind: concentrated brine, millions of litres of it a day.

Now scientists are sounding a note of caution about the impacts of dumping all that salt in the environment. “Increasing salinity is one of the most important environmental issues of the 21st century,” says engineer Amy Childress. But smarter methods of desalination are emerging and they have benefits far beyond providing clean water.

Sao Paulo, Cairo, Beijing, Bangalore – the list of cities with water shortages runs long and touches every continent. Even London, often thought of as a wet city, only gets about 600 millimetres of rain a year and will

probably have supply problems by 2025. As populations grow, things are set to worsen. In 2007, the UN found that about 1.6 billion people lacked adequate infrastructure to supply them with drinking water. By 2025, the organisation expects 1.8 billion people, almost a quarter of the world’s population, to be living in areas where there is not enough water to sustain them.

Ideally, we would meet demand by tapping into stores of fresh water such as rain-filled reservoirs and rivers, or perhaps groundwater wells. But plenty of places don’t have sufficient, easily accessible sources of fresh water to support growing populations. One option is to recycle waste water on a mammoth scale. Another is to turn to salty water, like the ocean or brackish lagoons.

The briny deep

Ocean desalination would provide drinking water for all – if only we knew

what to do with the waste salt. Katherine Bourzac reports



That is where desalination comes in, and there are plenty of ways to do it. For example, you can evaporate water from one spot and condense it in another, leaving salt and impurities behind. But the most energy-efficient method is reverse osmosis.

Imagine a strong salt solution and a weak one, separated by a membrane that allows only water through. In this situation, the water will flow naturally from the weak solution to the strong, evening out their concentrations in a process called osmosis. Do the reverse, forcing ocean water at high pressure through a salt-excluding membrane in the opposite direction, and you are well on the way to making drinking water.

This approach is becoming more common. In 2005, desalination produced

about 40 billion litres of water daily, according to the International Desalination Association. By 2015 that had increased to 87 billion litres, produced by nearly 1900 plants around the world. The vast majority of those are in the dry countries around the Persian Gulf, but the technology is on the up elsewhere too. The Australian city of Adelaide gets roughly half of its water from a huge desalination plant. California already has a few plants and is spending more than $30 million on eight new ones.

Great news. Except what about all that brine left behind? It is about twice as salty as the starting water, depending on the desalination technique used, and most plants dispose of it by pumping it back out to sea. That is a source of concern for researchers, including

Childress, who is based at the University of Southern California.

The concentration of salts in the sea varies. On average it is 35 parts per thousand, meaning that for every 1000 grams of seawater, about 35 grams is salt. Once salt levels exceed what marine plants and animals are used to, there is a danger that their cells might cease to work properly.

The evidence so far for what happens to life around brine outflows from desalination plants is mixed. In 2012, a study for the California State Water Resources Control Board looked at how animals responded to increased salt concentrations in lab >

For coastal communities, the ocean is a tempting source of water

SP

AC

ES

IMA

GE

S/P

LA

INP

ICT

UR

E



conditions. It found that many marine species would probably be fine in increased salinity. But some important ones, like giant kelp, would be at risk. Dense strands of these tall algae form underwater forests along the California coastline, and their canopies are home to a diverse range of species including sea otters and urchins.

Giant kelp reproduces most successfully at salinity levels between 25 and 35 parts per thousand, says Michael Foster at California’s Moss Landing Marine Laboratories. With the Pacific Ocean’s salinity already at 35 parts per thousand, any increase might be problematic for the kelp and the ecosystem it supports. The water control board study also found that red abalone, a prized edible mollusc, seems to be highly sensitive to salinity increases.

Heather Cooley, director of research at the Pacific Institute, a water think tank in California, is alert to the unintended consequences of brine disposal. “We don’t really know what the impacts will be on the marine environment,” she says.

Cooley has conducted an extensive review of the evidence, for example looking at levels of biodiversity and dissolved oxygen before and after the installation of brine outflows from desalination plants in Perth, Australia, and elsewhere. The results are not easy to interpret and do not necessary apply

elsewhere. Wave patterns, for instance, significantly influence brine dispersion, she says.

Still, the potential risks mean that most desalination plants must already dilute their brine before discharging it into the ocean. That in itself is problematic. The stuff used for the dilution is often cleaned-up waste water or water used to cool industrial facilities. It is clean enough to dump in the ocean but not quite drinkable.

That whole procedure is drenched in irony. Desalination plants are needed only where there is a lack of fresh water, yet they are taking fresh water that could be easily cleaned to make it drinkable, and instead flushing it into the sea. “Why aren’t we reusing that water?” says Cooley. “You’re treating it, then dumping it back in with desalination brine. It just defies logic.”

Childress thinks innovative engineering could stop this. In order to desalinate water, you have to fight against its natural tendency to flow from areas of low to high salt concentration. But if you let nature take its course – allowing forward, not reverse,

osmosis – it is possible to get more and more water to flow across a salt-excluding membrane into a container of brine, increasing the pressure. That pressurised water can be used to drive a turbine and generate electricity in a process called pressure-retarded forward osmosis (PRFO). Add this stage to a reverse-osmosis desalination plant and you not only dilute the waste brine, you also get power that can be fed back into the process or used however you like (see diagram, below).

Hybrid systems like this do not work perfectly yet. The first such facility, opened in 2009 and operated by Norwegian company Statkraft, closed after five years because it didn’t generate enough electricity to justify the building and operating costs. Childress is currently modelling similar systems in her lab to see if they can be made successful, though the details are under wraps.

There are hopeful signs elsewhere. Neal Tai-Shung Chung, a chemical engineer at the National University of Singapore, says his lab has developed the technology to a point where it makes economic sense. It comes not a moment too soon in his home country. “We don’t have energy and we don’t have water,” he says. Singapore buys a significant amount of water from neighbouring Malaysia, but the arrangement is set to expire in 35 years and has long been a political football.

Chung’s group set up a test system based on essentially the same idea as the Statkraft plant, but using the team’s own improved membranes. When the researchers ran the set-up for 500 hours, feeding it municipal waste water and seawater, its power consumption was just 1 watt per cubic metre of desalinated water made, a quarter of what is typically needed for reverse osmosis alone. A Singapore research incubator has taken up the designs and is planning a larger pilot plant.

Ultimate utopia

Some want to take desalination even further. Carry on removing water from brine, and you eventually get pure water and salt. Childress calls it the “ultimate utopian” desalination process. The technical name for it is zero liquid discharge (ZLD) desalination. Anyone who pulls off the feat would get three-fold rewards: zero brine, maximum fresh water and a haul of valuable compounds. In some cases that includes lithium salts, which would provide the crucial component of our best batteries.

“It’s amazing how much work has been done on this,” says Christopher Bellona,

“ The ideal desalination process will reap valuable minerals, not just water”

Dilution solutionDesalination produces concentrated brine. Pumping this back out to sea is a potential problem for the environment, but diluting it wastes water that could be otherwise recycled. Extracting energy from the dilution could make it worthwhile

Salt water from the sea

REVERSE OSMOSIS

PRESSURE RETARDED FORWARD OSMOSIS

MEMBRANE

FRESH WATER

WASTE WATER

Water treatment plant

Concentrated brine returned to the sea or...

...mixed with treated water before being returned to the sea

PRESSURE

PRESSURE

Pressure used to drive a turbine

producing electricity



an environmental engineer at the Colorado School of Mines. Chemists have explored mining just about any mineral from brines: uranium, lithium, rubidium, plain old table salt. But turning briny trash into treasure has never quite hit the big time, principally because the various salts are present at low concentrations and in mixtures that are hard to separate. There are, however, a few places where the economics finally add up.

Most desalination happens at the shoreline, but the US is an exception. Much of the country has groundwater reserves that tend to be salty, which is why 95 per cent of its desalination plants are inland. With no ocean to discharge into, the waste brine is even more of a problem than usual. Most of the time,

it gets dumped in rivers. Where land is cheap, it might be routed to evaporation ponds. In Texas and other places with favourable geology, it is injected into deep wells. But all these options have a limited capacity. That’s why Arizona is trying to get Mexican permission to build a brine-carrying canal to the sea, so far without success.

The largest inland desalination facility in the US is the Kay Bailey Hutchison plant in El Paso, Texas. It slakes the thirst of 2.7 million people and injects its brine into deep wells. That is expensive and the wells will be full before long, a combination that has breathed

new life into the ZLD dream. The plant has teamed up with Enviro Water Minerals of El Paso and, in April, they finished building a brine-mining facility inspired by, and using some technology from, the petroleum industry. The firm’s CEO Hubble Hausman calls it a “water refinery”. Just as crude oil can be separated into many valuable products, the facility separates brine into about five different streams, eventually extracting nearly all the water and a handful of useful compounds. These include hydrochloric acid, sodium hydroxide, gypsum and magnesium hydroxide, all of which are either used in industry or in building materials.

The facility will soon be running at full scale, recovering an additional 7.5 million litres of drinking water a day from the plant. There is no new technology involved, just existing tech in a new combination. “It’s a brilliant idea,” says Michael Mickley, a hydrologist and consultant in Colorado. “Whether it makes sense economically is the question.” Only time will tell.

Oily treasure trove

Other engineers are looking to turn waste water into treasure under even more challenging conditions. Benny Freeman at the University of Texas at Austin has his eye on oil wells, which extract five times as much water as oil. “There’s been talk about using the water, but the least expensive thing to do is pump it back into the ground,” he says.

Yet oil well water in Texas contains 1000 parts per million of lithium. Freeman has collaborated with chemists at Monash University in Australia to develop membranes that can selectively separate the element from water. Even if mining the lithium in this way makes economic sense, Freeman is the first to admit that turning this system into a full-on desalination process would be a challenge, but he says it is an obvious thing to try next.

The ZLD dream won’t work everywhere. But desalination is a tool that city and state planners need to have ready, says Childress. She says the only way to solve the problems that come with it is to embrace a diverse set of technologies and pick the options that work locally. The reason many of these more cutting-edge ideas are not widely used is not that they don’t work. Rather, it is that “we aren’t desperate enough yet”. Perhaps the lesson from Cape Town is that we soon will be. ■

Katherine Bourzac is a freelance science journalist

based in San Francisco

California is building 8 desalination plants. The effect of waste salt on kelp forests is unknown

RIC

HA

RD

HE

RR

MA

NN

/FL

PA

BL

OO

MB

ER

G/G

ET

TY



IN THE late 1980s, the medical industry was looking for new ways to treat women experiencing urinary incontinence and

vaginal prolapse, both relatively common conditions following childbirth. At the time, doctors suggested physiotherapy, weight loss and other non-surgical interventions, with complex surgery as a last resort.

When mesh implants came along, they seemed like a simple and convenient alternative: a flexible plastic scaffold that took less than an hour to implant and allowed women to leave hospital quickly and get on with their lives. Permanent mesh implants became standard treatment for millions of women with these conditions.

They have proved effective in many cases. But some women have experienced complications, including mesh eroding through the vaginal wall or piercing the bladder, nerve damage and infection. The implant can cause chronic pain, sometimes so severe women are barely able to walk.

Tens of thousands of women around the world have brought lawsuits. The US Food and Drug Administration reclassified mesh as a “high-risk” device in 2016. More recently, Australia and New Zealand have banned its use in some circumstances. And in July the UK’s National Health Service suspended the use of mesh in England for stress incontinence.

The mesh was designed to allow bodily tissue to grow through it, so it is very hard to remove. Sohier Elneil at University College Hospital in London is one of fewer than 10 surgeons in the UK able to carry out the procedure. She performed her first mesh removal in 2005 and, since then, has been

at the forefront of the campaign to raise awareness of mesh complications.

How bad is the situation? It’s a crisis that’s probably unprecedented – we still don’t know the depth of it. Worldwide, 3.7 million meshes were sold between 2005 and 2013, and we will have to monitor patients for the next 15 to 20 years.

The complication rate is around 1 in every 10 women who receive mesh, according to research I was involved with. And that’s just for the first five years after implantation – we have really limited information on longer-term outcomes. But there are indications that complications could be as high as 40 per cent for mesh inserted to treat prolapse.

The complications can be serious, so why have doctors been using the material for so long? Originally, the complication rates were

deemed to be between 1 and 3 per cent. But this was based on hospital data, where there was no standardised way to record mesh complications and removals. And these figures didn’t consider patients who had gone to a family doctor or pain clinic.

Why did you start removing mesh?Women with mesh implants would often come into the chronic pain clinic I ran with colleagues at University College Hospital in London. We initially focused on using medication and other pain management strategies but a significant group of patients did not respond. We concluded the only thing would be to try to remove this mesh.

Do women’s symptoms improve after the mesh is removed?In certain patients, things do improve and generally women are back on track. But the pain doesn’t always go away. There are long-term consequences even after you have taken the mesh out, including an autoimmune

The surgeon fixing a scandalThe worst consequences of vaginal mesh could have been avoided if doctors had taken women’s reports of pain seriously, surgeon and campaigner Sohier Elneil tells Julia Brown

INTERVIEW

Protesters outside the UK Houses of Parliament call for a halt to vaginal mesh implants

AL

ICIA

CA

NT

ER

/EY

EV

INE



response seen in some people, as well as complex nerve problems affecting the pelvis and lower limbs.

How many people in the UK are qualified to insert mesh?Hundreds are qualified to insert it, but relatively few are qualified to remove it. My training involved a lot of complex vaginal surgery, in particular in women who’d had really bad, traumatic childbirth. So my skill set came from that background. Mesh removal is difficult and occasionally scary surgery. The mesh adheres to the bladder, urethra, vagina, blood vessels, nerves and bones. Once removed, the symptoms of incontinence and prolapse often return and so one needs to consider non-mesh options to restore functionality. That can be difficult in tissue that has been chronically inflamed or infected by the mesh.

Even though others can do removals, I understand women seek you out.Many patients were dismissed for a long time,

so they lost trust in their doctors. They want somebody who will listen to them. There’s also a group of women who feel that nobody else can do their surgery, and there’s an element of truth to that: many surgeons are starting to learn how to deal with potential surgical complications, but many are still not far enough down the road of experience.

You and others face resistance for speaking out against mesh. What do you think is behind that? There has been a great deal of resistance, even anger, from some clinicians, even though evidence is coming out all the time. I think there are some who believe this is media hype and upset, and that women have jumped on the bandwagon. And of course if a surgeon is stopped from using mesh, and they haven’t

been trained in all the other complex surgical techniques, they cannot offer a surgical option to their patients, so they have no alternative. Some doctors are taking it personally: they fail to recognise that the injury isn’t to them – the injury is to the women.

So, what’s the alternative?Research shows that over 70 per cent of women with stress urinary incontinence who committed to physiotherapy did not need any further intervention. So, many clinicians are reverting to conservative measures first before considering surgery, and some are retraining in the traditional surgical techniques, which existed in the pre-mesh era.

How do you feel about the issue from a cultural perspective?It’s no longer just a mesh issue or a pain issue.This is about right of access to good healthcare, and belief in women: it’s a women’s rights issue. What makes me angry is the fact that many women affected by complications were not listened to. They were ignored, patronised, and many were sent to psychiatrists or psychologists when their problem was physical. Sometimes these women couldn’t walk unaided, couldn’t function, gave up their jobs, couldn’t look after their families – the impact on their quality of life was huge.

What has happened in the past few years has made me sad because it has affected the way I think about my profession. But occasionally in life, and especially in medicine, you must stand up because you have to make people think differently.

Is the situation getting better in the UK?Until the recent suspension led by Julia Cumberlege and her team in tandem with NHS England and the Department of Health, people were still using continence and prolapse mesh. The suspension has meant many have stopped, albeit temporarily. But we are just at the tip of the iceberg in dealing with the complications of the mesh already implanted. This is going to get bigger in years to come, globally. I have several trainees and colleagues working with me, learning how to do removals. And women are becoming much more aware. Many women are telling doctors: I’m not having this, thank you very much.

The suspension is a good result for the women: it is a vindication. I suspect using mesh will become more difficult from now on. ■

Julia Brown is an interview editor at New Scientist

“ This crisis is unprecedented. We still don’t know the depth of it”

Photographed for New Scientist by Dave Stock



ST

AN

LE

Y C

HO

W



FEW discoveries could be bigger than detecting life on another planet. Whether it is a rocky ball or a giant cloud of gas,

hot, cold, or somewhere in between, we aren’t picky: so long as a world has life, we want to find it.

For as long as we have searched, we have had one image in mind: Earth. It might seem like vanity, but our focus makes a certain amount of sense. After all, Earth is the only planet in the universe that we know for a fact supports life. Even if faraway exo-Earths don’t have oceans, continents, rainforests, deserts and polar caps, the long-standing assumption is that they will still be familiar in certain ways. There will be water on the surface, oxygen in the air, possibly even vegetation on the land.

But Earth hasn’t always looked the way it does now. In the 4.5 billion years our planet has existed, it has experienced dramatic transformations: ice ages and warming periods, times when the atmosphere was

twice around Earth, using the planet’s gravitational pull as a slingshot to power it on its way to its ultimate goal, Jupiter. The astronomer Carl Sagan suggested taking the opportunity to point our best alien-finding equipment at Earth itself. If it found nothing, he reasoned, that meant life elsewhere might also escape our attention.

Galileo was to be the first of several probes to use their instruments in this way, and they confirmed that our technological civilisation should be detectable by a distant, similarly advanced alien civilisation.

Where there are no hints of technology to home in on, by far the best life sign to latch on to is oxygen. Its abundance in our atmosphere – 21 per cent – would be difficult to sustain without plants pumping it out constantly. Methane, released by bacteria as well as flatulent livestock, is a more ambiguous biosignature, given that a number of non-biological mechanisms can produce the gas.

A bigger giveaway than either oxygen or methane on their own, however, is the presence of both. That is because the combination is combustible and releases energy when it reacts, forming carbon dioxide and water. “If these two gases are left to their own devices, they’ll usually annihilate,” says Chris Reinhard at the Georgia Institute of Technology. “The fact that they’re both present at relatively high abundance suggests that they’re being pumped into the atmosphere at very high rates, potentially by biology.”

Another reliable sign of life is the light reflected by plants. Although our planet’s vegetation absorbs most visible wavelengths, with the exception of green, it absorbs far less infrared light. The upshot is an abrupt jump – known as the red edge – in Earth’s reflectance spectrum, a phenomenon that would be hard to replicate without living organisms.

Searching for high levels of oxygen, methane coexisting with oxygen, or a red edge would be a good way of picking up planets that look like Earth now. But Earth has been inhabited – not to mention inhabitable – for far longer than it has displayed any of these features (see diagram, page 41).

The earliest known life forms emerged about 4 billion years ago, when the planet’s crust was cooling to form rocks and the beginnings of continents. At this time, known as the Archaean, Earth’s atmosphere would have been dominated by carbon dioxide produced by active volcanoes. In this hostile environment, primitive microbes emerged

Lessons from early EarthOur deepest history could hold the key to the search for life on other planets. Kelly Oakes reports

>

impossible to breathe, when large areas were desert, or when lush tropical forests hugged the poles. Throughout the vast majority of this turbulent history, life has somehow clung on.

If, armed with a spotters’ guide to the world we inhabit today, we found exoplanets resembling those early Earths, would we even recognise them for what they were? Maybe not. We know how to seek comparatively advanced signs of intelligent life, such as cacophonous radio transmissions and the bright lights of megacities. If a planet has less sophisticated inhabitants, however, we must rely on identifying other signatures of life. That is why scientists interested in filling in the blind spots of our search for intelligent life have started a lot closer to home. They want to imagine how early Earth would look if seen from far outside the solar system.

The first time we tried to study our planet from afar was when the Galileo mission launched in 1989. It was programmed to orbit



that made methane, and oxygen levels were at an all-time low. This was fortunate – if they had been any higher, life as we know it might not have emerged at all. “Oxygen poisons some of the prebiotic chemistry that we think culminated in the origin of life on Earth,” says Stephanie Olson at the University of California, Riverside.

A billion or so years later, the planet was entering a time called the Proterozoic. Photosynthesis was already well under way, but it was at this time that the ability to convert carbon dioxide into oxygen had lasting consequences for the planet. For the first time, oxygen, carbon dioxide and methane coexisted in the atmosphere, leading to the accelerated evolution of multicellular life.

During this time there were two “snowball Earth” events, when the entire planet was covered in ice. The trigger may have been something as trivial as a brief drop in global temperatures, allowing the polar ice caps to expand. This reflected more sunlight, reducing temperatures even more in a feedback loop that eventually froze the whole planet. The trouble is, we don’t know how freezing over would have affected the chance of spotting life from afar. “The composition of the atmosphere during the snowball Earth events is actually not terribly well known,” says Reinhard.

The Proterozoic’s defining feature, however,

was a billion-year period of apparent stability from 1.8 billion years to 800 million years ago. After the frenzied emergence of multicellular life, and the chaos of the first snowball Earth event, the planet relished the opportunity to take a breather. The climate was constant, life appeared to be evolving very slowly, if at all, and oxygen remained at low levels. Little wonder that geologists have taken to calling this the “boring billion”.

Oxygen masked

Some think that name is a tad unfair. After all, this was when sexual reproduction first evolved, and when the first eukaryotes – organisms with complex cells that ultimately gave rise to ourselves – appeared, “which is a big deal”, says Nick Butterfield at the University of Cambridge. From the perspective of an alien Galileo space probe, however, little would appear to change.

By the time the boring billion ended, life was really stepping on the accelerator pedal. At this time, called the Phanerozoic, the diversity of life forms skyrocketed in what is known as the Cambrian explosion, oxygen finally reached levels that would be remotely detectable and plants began to flourish on the planet’s surface. This is when the red edge would have first been visible.

This complicated history offers a stark lesson for those hunting exoplanets based on Earth’s current appearance. “For about four-fifths of Earth’s history we would not be able to see evidence of life on the surface,” says Reinhard. Whether searching for high oxygen levels, oxygen-methane coexistence or a red edge, you would mostly come up empty-handed. “The obvious candidates for biosignatures aren’t going to work as well as we thought,” says Olson.

Part of the problem is how little we know about early Earth. It is no exaggeration to say that, in some ways, we will soon know more about planets billions of kilometres away than we do about our own world billions of years in the past. With so little surviving evidence – and each piece so open to interpretation – reconstructing Earth’s history is a major challenge. Until the gaps are filled in, what life-hunting astronomers need is a broader-brush way of figuring out which planets to investigate further.

For Enric Pallé at the Institute of Astrophysics of the Canary Islands, one promising avenue is the ancient equivalent of red edge. Ever since the days of the Archaean, long before the continents became hotbeds

The emergence of vegetation dramatically changed Earth’s appearance from space

VIT

AL

IJ C

ER

EP

OK

/EY

EE

M/G

ET

TY

“ For about four-fifths of Earth’s history, we would not have been able to see evidence of life as we know it on the surface”



for vegetation, they were probably swamped by purple mats of single-celled bacteria. If these tiny organisms were present in great enough numbers, says Pallé, their effect on the light reflected from Earth would be similar to that of vegetation, but shifted toward the far red end of the spectrum. “You can envision a whole bunch of colours you can get,” says Abel Méndez, director of the Planetary Habitability Lab at the Arecibo Observatory in Puerto Rico, depending on which bacteria are most common.

Attractive though this sounds, its signal could be weak and tough to spot from afar. Olson and her colleagues think they have identified two more promising avenues. The first could be to observe planets over a long period, instead of just getting a snapshot of their atmosphere’s composition. Observing Earth in this way, for example, would reveal a seasonal change in atmospheric carbon dioxide levels. That is because plants use more carbon dioxide during their growing season, with the northern hemisphere dominating the effect because of its greater land mass. “You’d see that it’s kind of wobbly up and down once a year,” says Reinhard.

On plant-free planets like Proterozoic Earth, it is not likely that photosynthesis by microbes would be enough to cause clear oscillations in carbon dioxide levels. Instead, respiring organisms might produce similar seasonal variations in oxygen. And although oxygen levels themselves might be too low to spot from afar, the effect of their fluctuations on levels of other chemicals

such as ozone could conceivably be picked up.One downside of using seasonality as a

biosignature is that some worlds don’t have seasons. Méndez points out that planets around the smaller, dimmer stars that are Earth’s closest neighbours must orbit close to their star to be potentially habitable, but doing so means they tend to end up keeping the same face pointing toward their star all the time. “They are tidally locked,” he says, “so you won’t have any seasons.”

Delicate imbalance

The other idea Olson and her colleagues are working on could prove more fruitful. It involves rethinking how life might influence the make-up of an atmosphere. Much as methane and oxygen would not persist together on Earth if all present-day life disappeared, there are other combinations of gases that scientists regard as being in disequilibrium – that is, they would be hard to sustain without life. During the Archaean, for example, such was the imbalance of atmospheric methane with carbon dioxide, nitrogen and water that it would have been rapidly wiped out as soon as it stopped being produced.

But it isn’t necessary to look for all of those gases at once. Olson’s team argues that you need only see carbon dioxide and a sufficiently large amount of methane together in an atmosphere to realise something biological is probably afoot. And although the relative abundance of oxygen and methane would probably not have been measurable

from afar at any point in Earth’s history, that of carbon dioxide and methane might be. “A detectable carbon dioxide and methane disequilibrium is more likely on a broader range of planets,” says Olson, “including those with undetectable levels of oxygen.”

Butterfield thinks looking for these atmospheric imbalances is an interesting idea, but cautions against falling for alien life as the explanation. “Just seeing disequilibrium is interesting,” he says. “But it doesn’t necessarily have to be biological activity.”

Although false positives are inevitable, Olson is hopeful that clues like disequilibrium and seasonality will help fill in some of those blind spots in our search for life. For one thing, says Olson, “they’re not tied to specific metabolisms”. Alien life wouldn’t necessarily need to be like us, or even be carbon-based, for these potential biosignatures to reveal its existence on a distant planet.

Getting a good enough look to find out, however, isn’t going to be easy. Figuring out what is going on in the atmosphere of an exoplanet means gathering as much light as possible from it. But of course, planets don’t produce light; they only reflect it, and that signal is dwarfed by the light of their star. To separate them, we will need enormous telescopes like NASA’s James Webb telescope, due to launch in 2021, or the next generation of extremely large, ground-based telescopes. Even with these devices, the task will be tricky. Seasonality on an exoplanet will require so much telescope time, says Pallé, that “we will not be able to measure that, not as long as you or I are alive”.

No single measurement is ever going to be conclusive. By looking at the make-up of a planet’s atmosphere, how it changes over time and anything unusual that appears to be going on at the surface, researchers will instead build a slowly evolving picture of that world’s chances of hosting life. “It’s not going to be like a discovery where you dig something and you say, ‘That’s it! I found it’,” says Pallé. “It’s a process where we are slowly choosing our best candidate.”

Our continuing ignorance of aspects of Earth’s primordial past could also hamper the hunt for distant life. What set off the snowball Earths of the Proterozoic, for example, is still a mystery. Even if we spot an exoplanet in an ice age, says Reinhard, we won’t know how to interpret what we see. One of the biggest discoveries in history could elude us once again. ■

Kelly Oakes is a freelance writer based in London

103

102

101

100

10-1

10-2

10-3

10-4

10-5

10-6

Earth through the ages The characteristic signals of present-day life on Earth include the coexistence of methane and oxygen in the atmosphere. But life existed on the planet for billions of years before the atmospheric composition we see today formed

ARCHAEAN

Earliest signs of life

Oxygen appears in the atmosphere First land plants appear

Photosynthesis develops

SO

UR

CE

: AR

XIV

.OR

G/1

80

3.0

59

67

Re

lati

ve a

tmo

sph

eri

c co

nce

ntr

ati

on

TO

DA

Y

Glaciation”Snowball Earth”

Plate tectonics resemble modern Earth

PROTEROZOIC PHANEROZOIC

bya

Oxygen

Methane

3.54.0 3.0 2.5 2.0 1.5 1.0 0.5 0



Your Three-Body Problem trilogy, first published between 2006 and 2010, describes the 20-million-year-long fallout from humanity’s attempt to make contact with extraterrestrials. How well prepared are we for the arrival of an alien race like your Trisolarans?We are totally not ready yet. The technology we have is still primitive. If other civilisations visit – aliens who are able to travel distances of hundreds or even millions of light years to get here – the gap between our respective technologies would be about the same as that between humans and ants. How will a group of such highly civilised aliens even know that we are intelligent?

Actually, that problem works both ways. How does that ant wandering across your desk know you are the planet’s dominant species? You don’t know how to dig a hole, you don’t fondle delicious dead bugs and you don’t protect your queen. All you do is hit those square-shaped things in front of you – an activity that generates absolutely no food whatsoever. Ants don’t think humans are intelligent at all.

In Dark Forest, the middle volume of your trilogy, you wrote “Each civilization’s goal is survival”. This sounds like a Darwinian process, applied at a civilisation level. Is it possible to have a galactic ecosystem that is ethical?First, we haven’t discovered any extraterrestrial life form, not to mention any other civilisation! And if we are to picture what the universe would be like if there

were an enormous number of civilisations out there, we can only derive assumptions from our own experience. A glance over human history tells us that the rise and fall of a great many civilisations is the result of war.It is even more depressing when we think about inter-species interactions. What happens when a species meets a stronger,

more intellectually developed competitor? That thought gives me shudders. The Cretaceous-Paleogene extinction was a horrible event. Dinosaurs and many other animals and plants were killed. But consider what we are witnessing now. Every year, thousands of species disappear, because they ran up against humans. So, the survival theory in Dark Forest is reasonable. There could be a highly civilised cosmic ecosystem with high moral standards, but I think the possibility is low, given what we know about Earth’s history.

If we receive a message from the stars, should we respond?How to respond will be a decision for the entire world. We would need a consensus, as this would affect every one of us. I think we should be cautious, rather than recklessly respond to the message and expose our location. We simply don’t know whether we are talking to friends or enemies.

Some people think if a species enjoys a high level of civilisation, it is bound to maintain high moral standards. That’s very naive; we have no way of knowing whether that’s true.

Most of your stories have sad endings. Are you pessimistic about the development of civilisation?I’m absolutely positive about human survival. We will continue to develop our civilisation and expand not just on Earth, but also across the solar system, the galaxy, even the entire universe. But I’m absolutely pessimistic about the survival of the other species who currently share Earth with us. The development of human civilisation will eventually force other living things to go extinct or become our food.

Are you not concerned that the destruction of Earth’s ecosystems will threaten human survival? We are almost wholly reliant on science and technology for our survival already. We can create an environment to sustain ourselves with technology, even if the ecosystem collapses. The new system could be on Earth or in space; we might develop one system or hundreds of them. Frankly, these environments could probably only support humans, although we probably wouldn’t care about other species anyway. Humans are selfish, and because of our innate selfishness, I’m very confident that we can overcome any amount of environmental destruction.

CULTURE

Among the cruel stars

China’s leading sci-fi author Cixin Liu tells Yvaine Ye that the future is bright for our species – partly because we kill everything in our path

“Because of our selfishness, we can overcome any amount of environmental destruction”

ZA

CH

AR

Y B

AK

O/R

ED

UX

/EY

EV

INE

PROFILEDubbed “China’s Answer

to Arthur C. Clarke”

by The New Yorker,

Cixin Liu worked as a

computer engineer for

a power plant before

winning accolades in the

late 1990s as a writer of

galaxy-spanning science

fiction. In Liu’s thrillingly

pessimistic space

operas, intelligence does

not breed virtue, and the

most advanced cultures

live in fear of each other.

His 2004 novel Ball

Lightning has just been

published in English by

Atlantic Books.

Can we work together as civilisation develops further in the future?I believe we can work together. Even though we still have defined nations, and each nation pursues its own self-interest, the borderlines between nations, ethnicities and religions are disappearing. Technology is improving communication and accelerating cultural exchange. So, I think the concept of



DON’T MISS

ListenScience guru Bill Nye’s views on

the politics of space feature in the

latest instalment of astrophysicist

Neil deGrasse Tyson’s excellent

(if slightly hokey-sounding)

StarTalk All-Stars podcast.

PlayActions have consequences in

Growing the Galaxy: Boundless,

a game where every element –

from the politics to the buildings –

is left entirely in the hands of

the players. It launches on

11 September for PC and PS4.

VisitThe premiere of Marshmallow

Laser Feast’s immersive black hole

experience Distortions in

Spacetime kicks off this year’s

British Science Festival, in Hull

from 11 to 14 September.

LearnDiscover how conflict can shape

international science at “Science

and the First World War: the

aftermath”, a one-day conference

at London’s Royal Society on

13 September.

WatchCharlton Heston has crashed onto

a distant planet ruled by apes! Go

cheer him (or them) along at a

50th-anniversary screening of

Planet of the Apes (pictured) on

15 September at the National

Space Centre in Leicester. Doors

open at 6.30pm BST.

nationhood will eventually vanish. The world will share the same set of values and become a more united group.

The science in your stories is very detailed. Do you consult experts over its plausibility when you write?I have never checked with any experts for my novels. Not long ago, science fiction was a very marginal activity and science-

fiction writers didn’t have access to expert opinions. Those ideas and concepts of mine are all distilled from my own self-taught understanding of the science.

When you write stories, do you let your imagination fly free or is there a limit to how far you can travel? The imagination in science fiction has boundaries. Unlike fantasy, science fiction must follow natural laws and scientific rules.

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

For example, if you want to fly, you need a massive amount of energy to work against gravity. Riding a magical broom doesn’t work in science fiction.

But there’s something paradoxical about the science in science fiction. Although it sets boundaries, science doesn’t restrain our imagination; it only spurs it. What modern physics has revealed goes far beyond common sense. We zoom out, and the universe in science fiction is 40 billion light years across, consisting of millions of solar systems with countless planets. We zoom in, and quantum mechanics inspires us to create a world that we can hardly visualise. Science immensely expands the canvas for science fiction. Fantasy, on the other hand, operates almost entirely at one, human scale.

Does it bother you that your wife and daughter don’t like science fiction?Not at all. It is understandable that they don’t like it. Science fiction, wherever it comes from, has always been a niche genre, only enjoyed by a unique group of people. I write science fiction, not because I’m fond of literature, but because I’m fascinated by science.

Which area of science excites you the most?I’m interested in studies that probe the mysteries of nature and the universe, such as physics and cosmology. I spend a lot of time every day reading about them and following the latest news.

Do you think science fiction can predict the future?I don’t think science fiction predicts the future at all. It simply lays out some possibilities. The 2018 we are living in now is so very different from the 2018 I wrote about in my short story of that name. Back when I wrote 2018, that year seemed really, really far away – but here we are! ■

Yvaine Ye is a science reporter



Surreal Science: Loudon Collection

with Salvatore Arancio, Whitechapel

Gallery, London, to 6 January 2019

WHENEVER the artist Salvatore Arancio visits a new city, he heads for the nearest natural history museum. He goes partly for research: his eclectic output, spanning photography and ceramics, explores how we categorise and try to understand natural and geological processes.

In the main, though, Arancio wants to be overwhelmed. “A lot of these collections are so vast, after a while you find yourself wandering around in a spaced-out state, inventing mental landscapes and narratives. It’s that feeling I’m trying to evoke here,” he tells me as we watch the assembly of his new show, Surreal Science, a collaboration with art patron George Loudon.

Loudon famously collected work by Damien Hirst and his generation years before they became global celebrities – until the day a canvas he bought wouldn’t fit through his door.

At that point, Loudon turned to the books, images and models (in clay, felt, glass and plaster) that educated 19th-century science students. “Looking back, I can see the move was a natural one,” Loudon says. “Artists like Hirst and Mark Dion were exploring the way we catalogue and represent the world. Around the time that collection felt complete I was travelling to South America a lot, and I became interested in the scientific discoveries made there – by Charles Darwin, Alexander von Humboldt, Alfred Russel Wallace and Henry Walter Bates.”

This isn’t a collection in the sense that there is any demarcation

to it. “It’s somebody’s personal eye that chooses this over that,” says Loudon. Nevertheless, a clear theme has emerged: how the explosion of science in the 19th century meant that scientists had to turn artist to produce educational materials for students. And, when the burden became too much, how companies of artisans emerged to satisfy the demand.

Loudon’s collection has been shown before, at the Manchester Museum last year, but Surreal Science is a different enterprise. The objects, designed to be handled, are exhibited here on open shelves, bringing the visitor tantalisingly close to the work in a very un-museumlike manner. Needless to say this makes for a nerve-racking build.

This is the moment of truth

for Arancio, who had to plan this installation-cum-exhibition armed only with photographs of Loudon’s collection and sheets of careful measurements. It is the first chance he has had to see his arrangements realised in situ.

The ceramic pieces he has created provide a foil for the

items in Loudon’s collection. An arrangement of ceramic flowers above an anatomical cut-away torso suggests a mandrake-like marriage of vegetable and human. Next to it is a discomforting juxtaposition of plaster models of teeth and wax copies of lemons. Models of cell division are easily

mistaken for geodes. Again and again, Arancio’s ceramic pieces – pools, leaves, corals and tubular spider forms – mislead the eye, so we miscatalogue what we see.

“I tried to create pieces that carried George’s objects off into some kind of fantastic realm,” says Arancio. Even before key elements of the show are installed –proper lighting, a looping educational film from 1935 and an experimental soundtrack by The Focus Group – it is clear that the experiment has succeeded.

For Loudon, it is a vindication of his decision to collect objects that until recently weren’t recognised by the fine-art market. He moves from shelf to shelf, past exquisite Blaschka glass slugs, felt fungi, a meticulously repaired elephant bird egg. “Now these objects have lost their original purpose, we can look at them as objects of beauty,” he says. “I’m not claiming that this is art forever. I am saying it is art for today.” ■

George Loudon’s collection is explored in

his book Object Lessons (Ridinghouse)

CULTURE

A fantastical experimentCeramic art acts as a cunning foil for a collection of scientific curios, finds Simon Ings

Loudon’s collection includes wax lemons and an anatomical torso

“ The explosion of science meant scientists turned artist to produce materials for their students”

PLASTER ANATOMICAL DEMONSTRATION MODEL TORSO 19TH CENTURY 72X37X26CM FRANCE OR GERMANY IMAGE COURTESY GEORGE LOUDON COLLECTION, PHOTOGRAPH BY ROSAMOND PURCELL

TOP: FRANCESCO GARNIER VALLETTI TWO BOXES OF WAX FRUITS (LEMONS AND PEACHES) 19TH CENTURYTURINIMAGE COURTESY GEORGE LOUDON COLLECTION, PHOTOGRAPH BY ROSAMOND PURCELL


Please email your CV and

Resume to:

Director of Research

NBPOL OPRS PNGOPRA

Dami Research Station

New Britain Province

Papua New Guinea

Email: [email protected]

Deadline: 30/09/18

Based in the heart of the oil palm basin

of Papua New Guinea, the Papua New

Guinean Oil Palm Research Association

was established in 1981

www.pngopra.org/.

PNGOPRA is an NGO currently funded

by New Britain Palm Oil Limited

www.nbpol.com.pg a Sime Darby

Plantation subsidiary

http://www.simedarbyplantation.com

and SIPEF Group http://www.sipef.be/.

Amongst other disciplines PNGOPRA

is looking for a suitable Head of

Plant Pathology to manage our Plant

Pathology Research Section on oil

palm but also coconuts. The role

encompasses the daily management

and human resources aspects and the

production of recommendations to the

PNG oil palm industry supported by

research results.

Head of Plant Pathology

its diseases issues.

mentoring and training.

makers.

A generous expatriate remuneration package includes:




newscientistjobs.com

The Rosalind Franklin Institute, a new national research centre at the interface between the engineering, physical, and life sciences, is seeking three experienced and dynamic research leaders to deliver the Institute’s thematic research programmes. The Rosalind Franklin Institute has been created as an independent institute to develop and accelerate the application of disruptive technologies and next-generation physical science methods that will underpin future advances in the life sciences. The Institute has identified key technology focus areas which include new strategies and chemical tools for drug discovery, and a range of multi-modal imaging and analytical platforms.

The role;

Able to see the bigger picture, build effective partnerships, and engage with colleagues from academia, industry and other end users, you will shape the RFI’s major technology goals, develop the detailed case for equipment investment in each theme area and deliver these central facilities for your theme. Alongside the Institute Director and Science Leads for other thematic areas you will help to lay the foundations for the long-term success of this £100m UK Government investment.We are seeking science leaders in; * Biological Mass Spectrometry * Imaging with Sound and Light (INSIGHT) * Next Generation Chemistry for medicine The ideal candidate will be responsible for the growth and development of their theme area. You will be an experienced research leader, working at a professorial or equivalent level in either an academic institution or industry. In addition to a strong research track record and international reputation, you will have a clear understanding of collaborative R&D, and experience of leading successful teams. The science leads will be based primarily at Harwell, the location for the new Rosalind Franklin Institute hub building, with collaborative work expected in our partner spoke universities across the UK. We expect and support our team members to reflect the values of the organisation both internally and externally. Diversity is central to the Institute, and reflects the interdisciplinary, open approach to research and innovation which the Institute has been created to lead.

For further information on how to apply, and a full job description and person specification, please see the RFI website www.rfi.ac.uk.

We are seeking Science Leads in Biological Mass Spectrometry, Next Generation Chemistry for Medicine,

and Imaging with Sound and Light

TECHNICAL ADVISER

(MARINE POLLUTION)

basis. We provide the maritime industry with objective technical advice on how to respond effectively to oil and chemical spills in the marine environment. We are seeking a Technical Adviser to join our small London-based team. Our work is varied and challenging. It involves giving advice world-wide on the most appropriate methods for cleaning up oil and chemical spills from ships, minimising their impact on economic resources and the environment, and providing advice on compensation. Further details of ITOPF’s activities can be found at www.itopf.org.

or related discipline and also preferably have relevant practical experience of pollution control, and/or the effects of pollution on marine resources. Fluency in a language other than English would be a distinct advantage. The successful candidates must be willing to travel extensively, often at short notice, and be able to work under pressure.

presentation abilities, and computer literacy are all vital.

Starting salary (circa. £50K) will be commensurate with experience and include a

If you feel you meet the above criteria and would like to apply for the Technical Adviser position, please visit our website http://www.itopf.org/contact/careers and complete the application form. This should then be submitted along with your current CV and a covering letter outlining your suitability for the role.

For any further information please contact:Vanessa Holliday (HR Manager)

ITOPF Limited, 1 Oliver’s Yard, 55 City Road, London EC1Y 1HQTel: +44 (0)20 7566 6999


Closing date for applications – 5 October 2018 ITOPF does not have a sponsor licence (issued by the UK Government) to employ workers from other

countries who do not already have the right to work in the UK. This means that ITOPF can only employ people who can demonstrate their right to work in the UK before their employment starts.

The world’s most exciting festival of ideas and discovery

COSMOS ZONE SPONSOR

EARTH ZONE SPONSOR

B O O K Y O U R T I C K E T S N O W

newscientistlive.com

20 – 23 Sept 2018

ExCeL London




Image: Christof Van Der Walt

Enhance your teaching Career todayPearson have exciting opportunities for Science teachers to become

please visit www.edexcel.com/aa-recruitment

01483 548804

Leading

Recruitment SpecialistsFor the discerning scientist

Urgent roles:

�

�

�


Reach your ideal chemistry candidate

in print, online and on social media.

Visit newscientistjobs.com and

connect with thousands of chemistry

professionals the easy way

Contact us on

+44 (0)20 7611 1204 or [email protected]


Where else can you meet, reach and inspire 30,000 curious minds?To exhibit at the world’s greatest science festival contact us today:

email [email protected]

or call 020 7611 1248

WINNER

20 – 23 Sept 2018

ExCeL London

COSMOS ZONE SPONSOR

MAIN STAGE SPONSOR

OFFICIAL RECRUITMENT PARTNER

EARTH ZONE SPONSOR




[email protected] @newscientist newscientist

LETTERS

I bring good news and bad news on methane

From Iain Climie,Whitchurch, Hampshire, UKIlkka Savolainen points to the importance of reducing methane emissions to combat climate change (Letters, 18 August). I have good and bad news.

Much methane is emitted by ruminant livestock. The good news is the success of tests on the methane-reducing effect of adding the seaweed Asparagopsis taxiformis to livestock food (Letters, 18 November 2017).

The bad news is that there are signs of massive methane releases from previously frozen deposits (27 July 2013, p 16). These could easily outweigh any reductions in emissions from human activities.

I suspect the current mess is due to three major blunders. The first was the emphasis on setting

targets to cut emissions instead of controlling levels of greenhouse gases. Second, many measures that are essential if conventional wisdom is correct – from reducing waste and developing alternatives to fossil fuels to cutting livestock’s impact – are sensible regardless of the effect of human activities on climate change, and would be even if the world were cooling. Instead of pursuing such win-win options, effort was wasted bickering about whether human activities mattered. Third, and predictably, nobody wanted to pay to address these concerns or to have their consumer convenience affected.

Neoliberal capitalism is a Ponzi scheme

From John O’Hara, Mount Waverley, Victoria, AustraliaWhatever value Earth Overshoot Day may have as a measure of the

From Daniel Hackett, London, UKFred Pearce reports how lawsuits over

climate change might bring justice

along the lines of “polluter pays”

(18 August, p 38). But from where

might the payee raise the fines?

From taxes or from energy charges,

no doubt. There is thus a risk of

sending money in circles, unless the

EDITOR’S PICK

fines are all spent on preventative or at

least remedial works. This could make

the exercise of suing nearly pointless,

and could even bring into question the

whole idea of the value of money.

There will be little progress until

some system can be devised in which

economies aren’t pitted against each

other. Until then, the environment will

always be the loser because it has not

been costed or is a common resource,

as in the case of the atmosphere and

the oceans, with their capacity as a

heat-sink. When a truer cost-benefit

analysis of our lifestyle is calculated,

we will all have to admit we are out of

our depth. Fatalism based on religion

will have to be tackled, since humans

are the only agency that could solve

this. So bring on the court cases –

but realise this is but the opening

shot in a massive upheaval.

Polluter pays – but pays to whom?



“ Being wrong should be on the curriculum: what holds people back is fear of it”

rate at which we are thrashing the planet, Mathis Wackernagel is on the money in describing typical economic activity as the largest “Ponzi scheme” (4 August, p 20).

The dominant global economic paradigm in the developed world is neoliberal capitalism. It ticks four boxes recognised as defining a Ponzi scheme: it is predicated on infinite growth, which is an impossibility in a finite world; when growth stops it falls over; there is no way to a soft landing; and the precise point of collapse can’t be predicted. The reason this description hasn’t registered in mass consciousness is the longish time span to collapse.

From Fred White,Nottingham, UKOur society determines actions based on cost-effectiveness and profit potential at all scales, from the household up to government

level. This should work, but these actions are based on an economic system that draws down capital assets and counts them as profits. It assumes that continual growth is possible in a finite system and takes no account for cleaning up the consequences of actions.

Our descendants will be at a loss to know how a society capable of exploring other planets and editing the genome could possibly have done so with an accounting system that encourages two plus two to equal seven.

When glaciers have gone it’s too late to use valleys

From Perry Bebbington,Kimberley, Nottinghamshire, UKErik Foxcroft suggests using vacant glacial valleys as water reservoirs for pumped storage hydropower (Letters, 18 August). By the time the glaciers have

water (and it can get very hot).Energy generation must be

accompanied by appliances that enable the resulting heat to be used in the most practical way.

What is the role of stress in producing allergies?

From Piers Roberts, Hampton in Arden, West Midlands, UKThank you for the interesting article on allergies (11 August, p 28). I was amazed, though, to find no discussion of whether stress levels can have a role, either as a precursor of allergic reactions or in exacerbating them.

From Tony Kelly,Crook, County Durham, UKPenny Sarchet doesn’t mention a factor that, I am sure, contributes to allergies: stress. I refer to unrelenting mental stress to which there is no conceivable

retreated enough to make this viable I think it will be a bit too late to think about such storage.

Renewable energy thwarted by appliances

From Enid Smith,Linton, Cambridgeshire, UKPaul Whiteley suggests that instead of funding large-scale energy projects we should spend the money putting solar hot water panels on people’s roofs (Letters, 4 August). We have solar hot water panels on our roof, and they have saved us money for some years.

But our predominant use of warm water is to wash clothes. Needing a new washing machine, we couldn’t find one that took warm water from the system, only ones that took cold water that was then heated. The rise in our electric bills has been significant. Meanwhile we have excess hot

Kate Shaw MA, MS, PsyD responds to a report that we can train

ourselves to better know when we are wrong (1 September, p 14).

>

One of the foremost physicists of

mid-Victorian Britain, John Tyndall’s

contribution to science underpin our

understanding of climate change, the

atmosphere, and glaciology. He was

also a pioneering mountaineer,

friend to the political and

literary elite of his day, and one

of the great popular science

communicators of his time.

Roland Jackson’s

biography makes

perfect summer

reading.

SUMMER READING

9780198788959 | 576 pages | £25

“If you want to understand AI, you need to

read The Deep Learning Revolution.”

—Erik Brynjolfsson, Professor at MIT Sloan

School of Management

mitpress.mit.edu/revolution



[email protected] @newscientist newscientist

LETTERS

ending or solution. I am sure, for example, that at least some children who develop an allergy after starting school are the targets of bullying.

In Australia, they keep cats under curfew

From Robert Craig, Washingborough, Lincolnshire, UKHugh Boyd complains that farming is blamed for wildlife woes and mentions that domestic cats kill vast numbers of birds (Letters, 4 August). In some areas of Australia there are curfews for cats, in contrast to the strange UK policy of allowing them to roam anywhere at any time. Aboriginal communities have found that feral cats, blamed for driving up to 30 species into extinction, are a great source of food.

Terraforming Mars in the style of science fiction

From Bryn Glover, Kirkby Malzeard, North Yorkshire, UKI was surprised to read that “we” (whoever that might be) have ever dreamed of converting Mars into

an Earth-like world (4 August, p 6). No one – surely – has ever really proposed this as a practical possibility, outside the realms of science fiction. Have they?

Future geologists will define the Anthropocene

From Jeffrey Harte, Caringbah, New South Wales, AustraliaWhile the International Union of Geological Sciences (IUGS) has declared that we are still in the Holocene epoch (28 July, p 24), I believe the “Anthropocene” is functionally and stratigraphically different to the Holocene. But when did it start and what evidence is appropriate to distinguish the two?

The idea of a layer of plastic rubbish as a marker is unlikely to be appropriate, because over many millennia rock strata are reworked vertically and laterally. Perhaps, though, the result will be a band of “plastiglomerate” lithic material that could serve as a new worldwide marker. Maybe the growth of radionuclides in sediments accumulated since the 20th century will provide a

uniform marker. The priority of the IUGS may be nomenclature – defining eras, periods, epochs and ages. But it needs to acknowledge the impact of a species on the geological record and not, as Mark Maslin and Simon Lewis intimate, go out of its way to confuse members of the public.

My job has already fallen to digital technology

From Alastair Brotchie,London, UKYour article on rules that robots should follow contains the platitude “We must be careful it isn’t only employers that benefit from robots” (4 August, p 38). As one of many whose profession has already been digitally destroyed, I am tired of this feeble plea.

For 30 years I painted backdrops for theatre. Now all middle-skilled work in this field is done by large-scale digital printing. There isn’t enough high-skilled work to support the infrastructure of training and career progression, so we see the end of a profession that dates back to the Renaissance. The owners of this technology

Letters should be sent to:

Letters to the Editor, New Scientist,

25 Bedford Street, London, WC2E 9ES


Include your full postal address and telephone

number, and a reference (issue, page number, title)

to articles. We reserve the right to edit letters.

New Scientist Ltd reserves the right to

use any submissions sent to the letters column of

New Scientist magazine, in any other format.

TOM GAULD

now have all our jobs, but “progress” is both incremental and accidental. There is no way I or my colleagues can get the originators or the owners of this technology to share its benefits – nor those who should perhaps be described as “unemployers”.

Nor will this change. (How can it?) All benefits accrue to those who control the technology.

Digital technology tends to promote the most rapacious form of capitalism yet seen.

Relying on votes from unsustainable farmers

From Geoff Browne,Sydney, Australia.Chris Milligan warns that much of the world is in for a rough ride from climate change (Letters, 4 August). This is timely, given the drought gripping New South Wales as I write. What isn’t timely is the response of the Australian government. As usual it is dispensing vast amounts of “drought relief” cash without consideration of whether the changing climate is making this largesse misplaced.

How many farms are really viable in this new climate world? Has any research been done to establish the viability of raising hoofed animals on soils that are drying and deteriorating? Of course, the current government depends on the farmers’ party to stay in office.

For the record

Paul Jackson was not involved with

the refurbishment of the bridge that

collapsed in Genoa (25 August, p 4).



CROSSWORD

ACROSS

8 0 (4)

9 1988 sci-fi animation directed by

Katsuhiro Otomo (5)

10 European nuclear research

organisation (4)

11 Judith ___ (1949–1986),

astronaut killed in the Challenger

disaster (6)

12 BBC wildlife programme

presented by David Attenborough

from 1954 to 1963 (3,5)

13 Component of an electrical

circuit (8)

15 Seed-eating finch, Spinus spinus

(6)

17 Supercontinent of the late

Palaeozoic and early

Mesozoic eras (7)

19 In photography, the ratio of the

focal length of a lens to the

diameter of the aperture (1,6)

22 1986 sci-fi film directed by

James Cameron (6)

24 Phylum to which vertebrates

belong (8)

26 To install new technologies

within older systems (8)

28 Early steam locomotive designed

by George Stephenson (6)

30 Integrated circuit (4)

31 Rotary wing of, for example,

a helicopter (5)

32 Element, atomic number 10 (4)

Crossword No22

Compiled by Richard Smyth

1 Unit of hereditary information (4)

2 ___ bomb, ordnance designed by

Barnes Wallis (8)

3 Mechanical seal (6)

4 Organ found in the digestive tract

of many animals (7)

5 Nathan ___ (1910–1999),

Warsaw-born US mathematician

(8)

6 Sanitary clothing worn by

surgeons (6)

7 Genus of flowering plants; part of

the eye (4)

14 Form of electronic communication

(5)

16 Unreactive – like 32 Across (5)

18 Of a leaf, sword-shaped (8)

20 Field in which Robert G.

Edwards won the 2010

Nobel prize (8)

21 CH3CO

2–, for instance (7)

23 Moon of Jupiter (6)

25 Mechanical model of the solar

system (6)

27 Computing command; damselfly

genus; letter in the NATO

phonetic alphabet (4)

29 Reactive structure in organic

chemistry (4)

DOWN

ACROSS: 1 STIGMA, 4 STOMACHS, 10 ESPARTO, 11 CONTACT, 12 TWO, 13 JOLIOT-CURIE, 14 TRIUNE, 15 DISEASE, 19 ANDROID, 20 TRIODE, 23 ADAPTATIONS, 25 MOA, 26 SAND BAR, 27 FLICKER, 28 CHAINSAW, 29 ENGRAM. DOWN: 1 STEATITE, 2 IMPLOSION, 3 MARY JANE RATHBUN, 5 TECTONIC, 6 MANIC DEPRESSION, 7 CHAIR, 8 SUTTER, 9 BOYLE, 16 SHOEMAKER, 17 LISTERIA, 18 HEXAGRAM, 21 PARSEC, 22 WOLFF, 24 APNEA.

Answers to Crossword No21

The Perfect Gift for Anyone Interested in Space! Launch them into the worldwide space community with the British Interplanetary Society. Membership includes our

astronauts, space scientists and thought leaders. Join in with one of our technical projects and help design the future

of space exploration!

From £20/year (Under 22) and £70/year (Standard)

www.bis-space.comTelephone +44 (0)20 7735 3160



A CONGRESSIONAL candidate in

Florida who claims to have been

abducted by aliens says she doesn’t

want to be defined by the experience.

City councillor Bettina Rodriguez

Aguilera claims that blond, Christ-like

aliens took her aboard a UFO as a child,

where she learned that Africa was the

energy centre of the world, and a cave

in Malta hid thousands of non-human

skulls. Since then, she has remained

telepathically in touch with aliens.

Florida is well-known for its

weirdness, which may explain why

the Miami Herald endorsed Rodriguez

Aguilera ahead of eight other

candidates. Although her head may be

in the clouds, an editorial praised her

“boots on the ground experience”.

After all, stranger ideas endure in

Congress, such as American

exceptionalism and trickle-down

economics.

CAR-MAKER Volkswagen is under a cloud after installing hail cannons at its plant in Puebla, Mexico. After factory-fresh cars were damaged by hail storms, VW

installed large cannons in the car lots. These emit loud bangs every 6 seconds during threatening weather, with the sonic wave said to break up hailstones.

But local farmers claimed the cannons were to blame for a recent drop in rainfall, and demanded $3.7 million in damages. There is no evidence that sound cannons can disrupt rainfall, and even less evidence that they can shatter hailstones.

VW has replaced the cannons with nets, but Feedback thinks the farmers may still have a case. Having famously cheated on their emissions tests, might VW bear some responsibility for a changing climate?

NAPOLEON’S defeat at Waterloo

might be down to the eruption of

Mount Tambora in Indonesia two

months earlier. According to Matthew

Genge at Imperial College London,

volcanic eruptions can shoot

electrified volcanic ash into the upper

atmosphere, leading to increased

cloud formation and changing the

climate on a global scale.

That could be why an unseasonable

June downpour the night before the

battle left the ground so muddy that

it had to start late, allowing time for

the Prussian army to arrive and fight

alongside the British. A reminder to

always check with your volcanologist

when drawing up battle plans.

A REGIONAL council on New Zealand’s South Island has proposed a ban on domestic cats, in an effort to preserve local wildlife. Claws are out for the housepets, which are blamed for killing huge numbers of birds.

Aside from two species of bat, New Zealand has no native land mammals, and the cat ban is part of an ambitious project to make the island free of all non-native predators by 2050. The ban would not apply to existing pets, but no new cats would be permitted, gradually reducing the population to zero.

Some citizens were alarmed by the impending cat-astrophe. “It’s not even regulating people’s ability to have a cat. It’s saying you can’t have a cat,” Omaui cat owner Nico Jarvis told the Otago Daily Times. “It’s like a police state.”

A JAPANESE rail company has been

criticised for making employees sit

next to bullet trains passing at

300 kilometres per hour. The training

exercises were introduced at JR West

following an accident in 2015, when a

plate fell off the outside of a train and

damaged the car behind. Employees

must now huddle in a safety trench

next to the tracks as the levitating

train flies past.

“It is to give employees who

work with train cars an opportunity

to experience and understand

the importance of their work,”

a spokesperson told The Mainichi

newspaper. Graduates of the

demonstration have compared

the experience to public flogging.

Despite pleas from the

workers’ union, the company said

it had no plans to suspend the

petrifying programme.

THE mayor of a French seaside town closed the beach following a spate of advances by an amorous dolphin. Zafar, as the animal is known, has been pestering bathers in the Brittany town of Landévennec.

Zafar is a familiar presence in the area, and was previously well-behaved. But since coming into season, he has been rubbing himself against boats and bumping into swimmers. After one woman was lifted out of the water by the dolphin, the town’s mayor Roger Lars issued a decree that forbade approaching the animal or entering the water when it was present.

The ban was lifted, reports the Associated Press, after the frustrated Zafar left Landévennec to find relief elsewhere.

WHEN life gives you lemons, make

lemonade. But what if life doesn’t

give you any lemons? That question

was answered by a 69-year-old man

in Thermal, California, who was

discovered with about 360 kilograms

of lemons in his truck, allegedly stolen

from a nearby farm. NBC San Diego

reports that the arrest was part of a

wider police investigation into fruit

rustling. Feedback notes the alleged

lemon thief was apprehended on

Grapefruit Boulevard.

For more feedback, visit newscientist.com/feedback

FEEDBACK

You can send stories to Feedback by

email at [email protected].

Please include your home address.

This week’s and past Feedbacks can

be seen on our website.

In the Czech Republic, falling water levels have exposed “hunger stones” in the river Elbe, where people recorded earlier droughts. Inscribed on one stone is the message: “If you see me, weep”

PA

UL

MC

DE

VIT

T


Last words past and present at newscientist.com/lastword

THE LAST WORD

Eggstraordinary claimI’ve just read that eggs should not be

stored in a rack on the back of a fridge

door, the exact place where most

fridge manufacturers put the egg

rack. Before I revamp my fridge,

is there any truth to this? And if so,

what could it be?

Once an unfertilised egg drops out of the back of a chicken, it crosses the road towards decay. This is because chick embryos need to breathe, so eggs must be gas-permeable. Even in the absence of an embryo, carbon dioxide diffuses out through the shell, and this makes the interior less acidic. Water from the white, or albumen, also diffuses outwards and, by osmosis, into the yolk.

The egg white thus becomes inhospitable to healthy proteins,

which have a naturally folded structure that depends on the local acidity. This in turn swells the yolk and makes membrane more fragile. If you ever try to make a soufflé using old eggs, you will find that the whites and yolks have become inseparable.

All these processes speed up with temperature, so storing eggs in the fridge is a good start. But an open rack behind the door is not the best spot. When you open the fridge, you waft fresh, warm air

over any layer of carbon dioxide that has built up at the egg’s surface. This encourages yet more diffusion out of the egg, and thus yet more ageing. You also tend to shake the eggs, resulting in a more watery albumen by mixing the thick and thin components of the white.

The best place in the fridge to store eggs is probably in a sealed box, to prevent diffusion, and as low down as possible – in other words, in the coolest part. This slows the loss of carbon dioxide and water to the air, and also prevents the egg taking up odours from inside the fridge.

It is worth remembering that eggs emerge from a contaminated part of a bird’s anatomy, so routinely harbour bacteria, notably Salmonella enteritidis. A sealed box would stop egg-winds wafting over the other contents of your fridge. We should also clean the egg rack regularly, wherever in the fridge it may be.

I wonder if fridge-makers originally put egg racks inside the doors because they could not think what else to use these tiny spaces for. Simon GoodmanGriesheim, Germany

Eggs can be stored in the fridge, preferably in a box to slow water loss, but they should be taken out and allowed to reach room temperature before cooking. This is important if you like a soft yolk: oeufs en cocotte and eggs sunny side up don’t work otherwise, because when the white is cooked,

the yolk is still only lukewarm. I learned this back in the 60s when working as a short-order chef at a motorway services, where I also learned to crack eggs single-handed.Luce GilmoreCambridge, UK

Clean cut

Every so often, my adopted cat brings

home geckos in two pieces, namely

the still-moving tail and the rest of the

body (also still moving). But there is

never any obvious blood. Why?

Wild animals often must recover from severe injuries, or die. Where we live, I am repeatedly amazed to see game birds survive incidental injuries and regain normal use of loosely flapping broken legs or wings that had been very crooked.

The realities of natural selection are so extreme that many snakes, insects, fish or birds have developed highly effective self-healing abilities. As a result, they can afford to try to redirect attacks towards non-critical areas at their rear, in particular frills of hair, loosely set feathers, fake heads – or, indeed, sacrificial tails. Some animals even use their tail non-sacrificially to attract prey.

Many lizards have more or less fragile tails that distract predators by thrashing when broken off. If alarmed, some geckoes drop their tail whether or not something is tugging at it, an example of what is known as autotomy.

We pay £25 for every answer

published in New Scientist. To answer

a question or ask a new one please

email [email protected].

Questions should be scientific

enquiries about everyday phenomena,

and both questions and answers

should be concise. We reserve the right

to edit items for clarity and style. Please

include a postal address, daytime

telephone number and email address.

You can also send questions and

answers to The Last Word, New Scientist,

25 Bedford Street, London, WC2E 9ES.

New Scientist Ltd retains

total editorial control over the

published content and reserves all

rights to reuse question and answer

material that has been submitted by

readers in any medium or in any format

and at any time in the future. All

unanswered questions and previous

questions and answers are at

newscientist.com/lastword/

“ Did fridge-makers put egg racks inside fridge doors because they did not know how else to use the space?”

A tail is a major investment, served by its own artery. Letting it bleed would be fatal, so muscles at intervals along the blood vessels clamp the flow, and the blood clots rapidly. It is something surgeons can only envy. Jon RichfieldSomerset West, South Africa

Many lizards and geckos display this behaviour, which is known as autotomy. Where I live, there are no geckos but lots of wall lizards, which shelter in and around the garden. Occasionally, just moving one of my outside bins will reveal a wriggling tail, the startled lizard having made off.

My cat loves hunting lizards and has brought in tails – although less often now – but never both the tail and its owner together. The lizards do grow a new tail, but it lacks vertebrae and clearly doesn’t match the rest of the body.Terence HollingworthBlagnac, France

In Hawaii, I see geckos hunted by cattle egrets (both are invasive species there). The egrets walk on the tops of hedges and reach down to grab geckos with their beak. If one gets hold of the tail, I frequently see the gecko fall away, leaving the egret with only a tail in its mouth. If it grabs the body, the egret must still twist the gecko 90 degrees to swallow it, and so may still end up with just the tail.Stephen JohnsonEugene, Oregon, US


the ou delusion -...

Documents