A PULSAR that is rotating just
once every 76 seconds raises
questions about how long these
star remnants can remain active.
When a giant star explodes
as a supernova, it can leave
behind a dense core in the form
of a neutron star. If this core is
highly magnetised and spinning
rapidly, it can send out regular
pulses of radio emissions, and
is known as a pulsar.
Manisha Caleb at the
University of Manchester,
UK, and her colleagues have
discovered a particularly odd
pulsar called PSR J0901-
using observations from
the MeerKAT radio telescope
in South Africa.Located about 1000 light
years from Earth, it rotates far
slower than any known active
pulsar, sending out a regular
300-millisecond-long pulse
every 76 seconds (Nature
Astronomy, DOI: 10.1038/
s41550-022-01688-x).“This is a very unusual
type of radio-emitting neutron
star,” says Caleb. “It resides
in what we call the ‘neutron
star graveyard’ where we
don’t expect pulses to emit.
It’s like a zombie star.”
Pulsars typically spin once
every 0.25 to 2 seconds, but as
they age, they lose energy and
spin more slowly. Eventually,
they stop sending out pulses
and become regular neutron
stars in a stellar graveyard.
The boundary that this occurs
at is known as the “death line”.
The discovery more than
doubles the previous record
for the slowest-spinning pulsar,
which took 23 seconds to
rotate. So our understanding
of where the death line begins
“may need to be revisited”, says
Caleb. “Sources in the neutron
star graveyard can still emit.”
The fact that the star is still
a pulsar challenges some
theoretical models, says Cole
Miller at the University of
Maryland, College Park. ❚TOURNIQUETS have long been
used on battlefields, and are now
employed by medics responding
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Over time, their design has been
honed to a nylon strap that doesn’t
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to constrict blood flow in a limb
and stop bleeding.
But getting hold of them can
be difficult in conflict zones.
Limited supply chains and
blockades in places like Gaza,
Myanmar and Ukraine make
these devices expensive and
often hard to buy.Now, several organisations have
created open-source tourniquet
designs that can be made anywhere
people have a 3D printer, internet
access and a spool of PETG plastic.
The 3D-printed components
include a buckle and windlass,
the tightening device made up
of a strong barrel and locking clip.
These can then be sewn together
with a nylon and Velcro strap.
The Glia Tourniquet by
Canadian company Glia has
been available since 2018. It was
designed to be manufactured
using solar-powered 3D printers
in Gaza, where an ongoing
blockade limits access to
basic medical supplies.
Most tourniquets now sold
are designed for adult soldiers.
Glia’s design is for a broader
range of people, including
children, and requires only
about 60 grams of PETG plastic,10 | New Scientist | 4 June 2022TechnologyJames StoutGL
IA
SpaceJonathan O’CallaghanNews
3D-printed tourniquets
could help save lives
at a cost of about $1 per tourniquet.
Others have now developed
similar products in response to
Russia’s invasion of Ukraine.
3D Printing for Ukraine, a group
of volunteers, published its design
in March. It allows plastic parts to
be printed anywhere in the world,
then tested and shipped to Poland,
Switzerland or western Ukraine to
be assembled and sent to the front
lines. Other tourniquets are being
printed in Ukraine using machines
and spools of printer plastic
donated by Polish firm Sygnis.
In Myanmar, where more
than a thousand civilians have
been killed after a February 2021
military coup, groups are using
3D printers to produce everything
from tourniquets to weapons.
Supply chains were slow before
the civil war, so farmers have
been printing tools there for
some time. Now those printers
are churning out medical devices.
Accessibility of 3D printing
makes it useful for production
in war zones, but ensuring that
products are robust is key. “It is
really important to have a high
standard of safety,” says Carrie
Wakem, Glia’s executive director.
3D Printing for Ukraine tests
each batch before sending it to the
front lines, and reports of failures
or suggestions for improvements
are sent back to individual makers
or the community as a whole.
Wakem says Ukrainian
medical authorities have got
hundreds of printed tourniquets
and are working on an open
source quality-control test.
A former US Special Forces
medical sergeant, who asked not
to be named because he works
in security in conflict zones, told
New Scientist that, until there is
rigid standardised testing, he can’t
recommend use of 3D-printed
tourniquets. “But there definitely
could be some promise,” he says. ❚SH
UTTE
RS
TOCK
/NASA
IMAGES76
seconds, the time between
flashes from a “zombie” pulsar3D printing
tourniquet
designed
by Canadian
company
Glia‘Zombie’ pulsar
is active member
of star graveyard
Artist’s impression
of a pulsar, a rotating
neutron star