New Scientist 14Mar2020

(C. Jardin) #1
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,
“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



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