New Scientist 14Mar2020

18 | New Scientist | 14 March 2020

Global warming

Gold-coated fabric

could be safety boon

STRETCHABLE, light-emitting

clothes made from fabric coated in

gold could be a smart alternative

to high-visibility gear – not to

mention a bold fashion statement.

Tricia Carmichael at the

University of Windsor, Canada,

and her colleagues started with a

fabric that is 87 per cent nylon and

13 per cent spandex. They added a

very thin coating of gold to act as

an electrode and send power to a

Moon rocks do show

trace of giant impact

WE HAVE found new evidence in

moon rocks to support the leading

hypothesis about our satellite’s

birth – that a Mars-sized object

called Theia hit Earth 4.5 billion

years ago in a giant impact.

If this idea is accurate, it would

have involved debris being blasted

into orbit around our planet which

later fused to become the moon.

As a result, we would expect the

rocks on the moon to look like

a mix of Earth and Theia, but

samples from the moon show that

oxygen isotope levels look a lot

like those in Earth rock. So what

happened to the bits of Theia?

Fresh light has been shed on

this by Erick Cano at the University

of New Mexico and his colleagues

who have conducted a new

analysis of lunar rocks. They

were able to take more precise

measurements than had been

done previously, while also

Solar system^ Materials science

THE recent bush fires in Australia

were made more likely by human-

made climate change, an

international team has found.

An analysis by World Weather

Attribution (WWA), an international

climate initiative, discovered that

the weather conditions responsible

for the fires were made at least

30 per cent more likely because

of human-induced warming. Two

climate phenomena, the Indian

Ocean dipole and southern annular

mode, were also found to have

played a big role.

Debate has raged over the cause

of the fires, with Australian prime

minister Scott Morrison calling

them business as usual, while

misinformation campaigns

blamed arson by green activists.

The WWA ran climate models of

a world with and without human-

made climate change to identify any

effect on the bush fires. They didn’t

find humanity’s fingerprint in

monthly and annual drought

records, but they did find one in a

fire weather index, a measure of

weather conditions, including

temperature, wind and humidity,

that make fire more or less likely.

Friederike Otto at the University

of Oxford, part of the WWA team,

says: “Because of climate change

alone, we find at least a 30 per cent

increase in the likelihood of these

events to occur.” But the true figure

is likely much larger, she says,

because the models underestimate

the role of temperature rises.

The attribution analysis looked

only at south-east Australia.

Overall, the fires burned 19 million

hectares and destroyed nearly

6000 buildings. Adam Vaughan

Our carbon emissions made

Australia’s fires more likely

light-emitting material (pictured)

in a range of patterns.

The fabric as a whole is semi-

transparent, so light can shine

through it. Carmichael says it has

big advantages over existing high-

visibility gear, which relies on

reflecting light from other sources.

But it will be a while before

such light-emitting clothes

hit the shops, as the current

version requires an unfashionable

battery pack about the size of a

deck of cards. One alternative the

researchers are looking at would

be to harvest energy directly from

the movement of the wearer’s

body (Matter, doi.org/dpbv).

“Having clothing that can light

up without requiring an external

light source would be valuable,”

says Clara Barker at the University

of Oxford, but the team will need

to look at durability, cost and

battery life. “A heavy, poor lasting

or unreliable battery will be a

critical factor in the success of

this technology,” she says.

Layal Liverpool

considering both the type of rock

and where they were found – and

discovered huge variation in

oxygen isotope levels.

“While Earth rocks occupy a

very narrow range of oxygen

isotope compositions, the lunar

samples demonstrated nearly

three times that variability,” says

Cano. He says this had been

overlooked in the past because

rocks returned from the moon are

in limited supply and researchers

rarely get to analyse a lot of them.

The team found that the lunar

rocks from the deepest parts of the

moon showed the most variation

in oxygen isotope levels compared

with rocks from Earth (Nature

Astronomy, DOI: 10.1038/s41561-

020-0550-0). Cano says that these

could be the most representative

of Theia’s original composition.

“This work is definitely a very

big deal,” says Sara Russell at the

Natural History Museum in

London. She says the findings give

more support to the giant-impact

idea. Jason Arunn Murugesu

ANDREW MERRY/GETTY

THE CARMICHAEL LAB

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