2019-06-01_New_Scientist

1 June 2019 | New Scientist | 17

Social networks

Drones Ecology

Women less likely

to receive CPR

An analysis of more than

5700 cardiac arrests in the

Netherlands has found that

only 68 per cent of women

received a resuscitation

attempt from a bystander,

compared with 73 per cent

of men (European Heart

Journal, doi.org/c55n). This

may be because symptoms

more commonly reported

by women than men – such

as fainting, fatigue and

vomiting – are less obvious

than chest pain.

Chimps’ ingenuity

earns them a treat

Chimpanzees in West Africa

have learned how to get

hold of tortoise meat. The

apes, in Gabon, were seen

bashing the soft underside

of the shells against tree

trunks to crack them open

and get to the animals’

flesh (Scientific Reports,

doi.org/c56k).

Keeping cool

with wood

A material made by

treating wood with

hydrogen peroxide

could keep houses cool.

It reflects visible light

and only absorbs very

low levels of near-infrared

light, so would transmit

barely any heat from the

sun indoors (Science,

doi.org/c57x).

How to burst your

social media bubble

AS EUROPEAN parliamentary

elections neared last week,

Facebook was again awash with

misinformation. In response,

it barred dozens of suspicious

pages and groups.

But new accounts can pop up

very quickly, so another approach

is to try to prevent misinformation

from reverberating in so-called

echo chambers. These segregated

groups lack the range of opinions

that can help counter fake news.

A SHAPE-SHIFTING drone is ready

for almost any environment, with

the ability to transform itself into

a car on command.

Called FSTAR, it can navigate a

range of surfaces and environments,

making it potentially useful for

search and rescue. With a wheel

and a propeller on each of its four

legs, it is about 35 centimetres long.

During operation, a person uses

a controller to steer the drone.

When flying, its legs are parallel

to the ground. When it lands and

receives the command to turn into

a car, its legs lower so that its

wheels can touch the ground.

FSTAR’s wheels are slanted,

which offers an advantage over

vertical wheels. “They are more

stable, especially on smooth

surfaces, so you can drive at

a higher speed,” says David

Zarrouk at Ben-Gurion University

of the Negev in Israel, one of the

drone’s creators.

FSTAR can drive at up to

2.6 metres per second and reach

15 metres per second when flying.

In tests, it could crawl over rubble,

lower itself to squeeze under small

gaps or fly over bigger obstacles.

Work on the drone was presented

at the International Conference

on Robotics and Automation in

Montreal, Canada. Yvaine Ye

A new analysis has found a few

simple tweaks to combat this.

Kazutoshi Sasahara at Indiana

University and his colleagues have

shown that the structure of social

networks makes echo chambers

inevitable – especially the ability

to unfollow or unfriend whoever

you like. This means it is easy to

cut off views you disagree with.

They also found that when

social networks recommend that

users follow friends of friends –

people who are likely to share

similar views – echo chambers

form more than twice as quickly.

Sasahara and his colleagues

Downsized future

for life on Earth

ANIMALS, collectively speaking,

are getting smaller, as humans

drive big beasts such as elephants

to extinction, with far-reaching

consequences for ecosystems.

Previous studies have shown

that bigger animals are at a greater

risk of dying out. Now a model of

the next 100 years predicts that

habitat destruction, poaching and

other pressures will cause an

overall decline in body size.

Researchers led by Rob Cooke

at the University of Southampton,

UK, modelled the future of 15,

endangered species. Critically

endangered ones such as the black

rhinoceros were given a 99 per

cent likelihood of disappearing,

while vulnerable ones had a 10 per

cent chance. The results showed

the loss of big species would see

the average body mass of animals

drop around 9 per cent from today,

to 64.1 grams in 2119 (Nature

Communications, doi.org/c56x).

This matters, and not just

because we care about charismatic

megafauna – tigers and so on. Big

species can be vital for ecosystems,

such as herbivores keeping grass

productive. They also perform

roles that help us, like scavenging.

For example, where vultures have

declined, disease has risen.

Adam Vaughan

suggest that social networks could

try to prevent echo chambers by

making it harder for people to

sever connections with those

with different opinions. Users

should be encouraged to “snooze”

an account rather than stop

following it entirely or be alerted

when they are about to unfollow

their last source of a particular

type of information.

Similarly, the researchers say

social networks should avoid

recommending new connections

that are likely to reinforce

opinions too strongly (arxiv.org/

abs/1905.03919). Douglas Heaven

Transformer flies, drives and

squeezes past obstacles

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Really brief

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