New Scientist - USA (2019-07-13)

13 July 2019 | New Scientist | 17

Space exploration

Archaeology Computing

Largest ever patch

of seaweed seen

Satellites have revealed

a 9000-kilometre algae

bloom stretching from

West Africa to the Gulf

of Mexico, spurred on

by fertiliser discharged

from the Amazon river.

The seaweed hampers

marine life, as well as

plaguing coastal towns that

have to keep removing it

from beaches (pictured).

Cockatoo learns a

dance move or two

A cockatoo called Snowball

has invented 14 different

dance moves to music.

They include body rolls and

head banging with a foot

in the air (Current Biology,

doi.org/dsds9s). Sulphur-

crested cockatoos like

Snowball are smart and can

use tools. However, they

are not known to dance

in this way in the wild.

Zika babies can

make a recovery

Among a group of 216

babies born to mothers

who contracted Zika virus,

about one-third had

developmental delays.

However, a new study has

found about half of the

affected babies had normal

developmental test results

by age 3 (Nature Medicine,

DOI: 10.1038/s41591-

019-0496-1).

Solar panels in space

just got a bit easier

A SPECIAL plastic can make folded

solar panels unfurl on their own

when exposed to sunlight. This

might be helpful for the panels

that power some spacecraft.

Such panels have to be launched

in a small container and opened

out in orbit. This usually relies on

something like a coiled spring or

a motor. But Chiara Daraio at the

California Institute of Technology

and her team have built a solar cell

that unfolds itself using a shape-

DNA from skeletons suggests the

Philistine people mentioned in the

Bible were a genetically distinct

community with ties to an influx

of Aegean immigrants.

The Old Testament makes many

references to the Philistines, often

as adversaries of Hebrew people.

To find out more about them,

Michal Feldman at the Max Planck

Institute for the Science of Human

History in Jena, Germany, and her

team used DNA from 10 skeletons

found in the ancient Philistine city

of Ashkelon (pictured), on the coast

of what is now Israel. The earliest

three remains date to about 1600

BC, four were infants buried around

1200 BC, and three individuals date

to about 1100 BC. Their DNA was

compared with DNA from all over

the world, both ancient and modern.

Those from the middle period had

significant ancestry from southern

Europe, but this signal had faded in

the most recent group, probably as

a result of assimilation with locals

(Science Advances, doi.org/c7zc).

The new genetic data, together

with existing archaeological data

such as Greek-style pottery found

in Philistine cities, strengthens the

case that such places saw migration

from Greece and western Turkey,

says Christoph Bachhuber at the

University of Oxford. Clare Wilson

memory polymer which can be

packed away and then return to

a set shape when warmed.

They started with a plastic ring

from an expanding toy called a

Hoberman sphere. The ring

comprises a series of hinged joints

that allow it to take on a much

smaller size. The researchers

replaced the hinges with polymers

that expand when exposed to

temperatures above about 35°C.

They stretched a sheet of shape-

memory polymer across the ring,

and covered it with shards of solar

panel. They arranged the shards so

that when the ring was collapsed,

Sweet answer for

safer data storage

WE KNOW DNA can be used for

digital storage. Now it turns out

that solutions of sugars, amino

acids and other small molecules

could replace hard drives too.

Jacob Rosenstein and his

colleagues at Brown University,

Rhode Island, stored and retrieved

pictures of an Egyptian cat, an ibex

and an anchor using an array of

these small molecules. They say

storing data this way could make

it less vulnerable to hacking and

better for use in more extreme

environmental conditions.

Rosenstein’s team created

mixtures of common metabolites,

solutions containing sugars,

amino acids and other small

molecules that humans and other

living organisms use to digest

food and to carry out other

important chemical functions.

The presence or absence of

particular metabolites in different

drops of the mixtures represented

the binary 1s and 0s to encode

information. Rosenstein and his

colleagues used many separate

drops on a plate to store data and

were able to retrieve it with around

99 per cent accuracy. They did this

by using a mass spectrometer to

analyse the chemical mix within

each drop (PLoS One, doi.org/

c7x6). Ruby Prosser Scully

the pre-creased sheet would twist

them into a tight bundle, known

as a flasher origami fold.

When the folded apparatus was

exposed to heat, the expansion of

both the hinges and the creases

in the sheet caused the shards

to unfurl into a solar panel, its

surface area going from 5 square

centimetres to half a square metre

in under 40 seconds (Physical

Review Applied, doi.org/c7zz).

This could be used as a simpler

solar power device for spacecraft

that unfolds when exposed to

sunshine after launch, says Daraio.

Leah Crane

Biblical Philistines had

genetic link to Greeks

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Really brief

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