New Scientist - USA (2020-04-25)

18 | New Scientist | 25 April 2020

Space flight

Bats copy calls in mini

recording studios

BATS can learn to mimic specific

sounds, which puts them into

an elite group of animals.

Ella Lattenkamp at the

Max Planck Institute for

Psycholinguistics in Nijmegen, the

Netherlands, and her colleagues

put six adult pale spear-nosed

bats in mini recording studios

equipped with microphones,

speakers and remote-controlled

feeding devices. They then trained

Quantum chips

heat up – a tiny bit

FOR the first time, quantum

computer chips have been

operated at a temperature above

-272°C, or 1 kelvin. That may still

seem frigid, but it is just warm

enough to potentially enable a

huge leap in their capabilities.

Quantum computers are made

of quantum bits, or qubits, which

can be built in several ways. One

that is receiving attention from

some of the big players consists

of electrons on a silicon chip.

These systems usually function

only below 100 millikelvin,

or -273.05°C, so the qubits

have to be stored in powerful

refrigerators. The electronics

that power them won’t run at

such low temperatures, and also

emit heat that could disrupt the

qubits, so they are generally stored

outside the refrigerators with

each qubit connected by a wire

to its electronic controller.

Computing Animal behaviour

ASTRONAUTS’ brains increase in

volume after prolonged periods

in space, causing pressure to build

up in their heads. This may explain

why some astronauts have vision

problems after returning to Earth.

“This raises additional concerns

for long-duration interplanetary

travel, such as the future mission

to Mars,” says Larry Kramer at

the University of Texas Health

Science Center at Houston.

Kramer and his colleagues

scanned the brains of 11 astronauts

before they spent about six months

on the International Space Station,

and at six points over the year

after they returned to Earth. All

the astronauts had increased brain

volume – including white matter,

grey matter and cerebrospinal

fluid – after returning from space

(Radiology, doi.org/dr7h).

Under normal gravity, it is

thought that fluid in the brain

moves downwards when we stand

upright. But there is evidence that

the microgravity of space prevents

this, resulting in an accumulation

of fluid in the brain and skull.

The astronauts’ brain volume

increased by 2 per cent on average,

which could result in higher

intracranial pressure, says Kramer.

He suspects this might press on the

optic nerve, potentially explaining

the reported vision problems.

Kramer’s team is working on

methods to counteract the brain

changes by using artificial gravity.

These pull blood back towards the

feet and could include a human-

sized centrifuge that would spin a

person around at high speed, or a

vacuum chamber around the lower

half of the body. Layal Liverpool

Being in space for a long

time increases brain volume

the bats to imitate their own calls

by bribing them with mashed

banana if they repeated the sound.

The researchers recorded the

bats’ calls, then manipulated the

recordings to lower the frequency.

They then repeatedly exposed

the bats to different sounds,

rewarding the animals whenever

they imitated one correctly.

Within 30 days, all six bats had

learned to lower the frequency of

their calls to mimic the recordings

(Biology Letters, doi.org/ggr7gn).

The ability to imitate sounds,

called vocal production learning,

is rare. Humans can do it, as can

some birds, as well as elephants,

seals, dolphins and whales.

It is difficult, says Lattenkamp.

“You have to memorise the sound,

produce it and then you have

to hear again what you just

produced and compare it with

the template in your head.”

Vocal production learning

is crucial for speech, so studying

it in other mammals may show

how it developed in humans. LL

This makes it hard to scale up.

“It works for two qubits, but not for

a million,” says Menno Veldhorst

at QuTech in the Netherlands.

Veldhorst and his colleagues,

along with another team led by

researchers at the University of

New South Wales (UNSW) in

Australia, have now demonstrated

that these qubits can be operated

at higher temperatures.

The UNSW team was able to

control the state of two qubits

on a chip at temperatures up to

1.5 kelvin, and Veldhorst’s group

used two qubits at 1.1 kelvin in

what is called a logic gate, which

performs the basic operations

that make up more complex

calculations (Nature, doi.org/

ggsbjk and doi.org/dr7r).

Now qubits can function at

higher temperatures, the next step

is incorporating the electronics

onto the same chip. “I hope that

after we have that circuit, it won’t

be too hard to scale to something

with practical applications,”

says Veldhorst. Leah Crane

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