Science

Science highlights: Warm Antartica and glasses with expression

Sarah Wild

The world of science is filled iwth interesting, quirky and downright strange discoveries. Science editor Sarah Wild chooses some of this week's best.

Warm welcome to Antarctica

It is the coldest place on Earth. Satellites have recorded temperatures of lower than -90°C on the surface of Antarctica, and the snow that falls does not melt but is compacted into ice.

But scientists from Yale University have found that during the Eocence epoch, 40- to 50-million years ago, its temperatures were about the same as they are in Johannesburg and Cape Town during autumn-winter.

Today, the South Pacific Sea near Antarctica is well below freezing; then it was about 22°C. The Eocene epoch was characterised by high concentrations of greenhouse gases, which the scientists claim was a reason for these high temperatures.

"Quantifying past temperatures helps us understand the sensitivity of the climate system to greenhouse gases, and especially the amplification of global warming in polar regions," Hagit Affek, an associate professor of geology and geophysics at Yale, said.

They used a new technique to measure the temperatures, called "carbonate clumped isotope thermometry", which involves two rare substances found in fossil shells to determine the historic climate. The concentration of bonds between carbon-13 and oxygen-18 reflect the temperature in which the shells grew, the researchers said.

"We managed to combine data from a variety of geochemical ­techniques on past environmental conditions with climate model simulations to learn something new about how the Earth's climate system works under conditions different from its current state," Affek said.

iEye, captain

From the land that brought us dirty underwear in a vending machine, we now have fake-expression spectacles, the "AgencyGlass".

Hirotaka Osawa from Japan's Tsukuba University has developed glasses that have LED screens where a person's eyes would be and allows the wearer to choose the expression they want to show the world.

You could seem to be looking happily at someone, the corners of your eyes crinkling with every appearance of enjoying their company, whereas behind the shield you are in fact looking over their shoulder for someone else to talk to. On the one hand, it is modern society's latest attempt to doctor the image that we present to the world – think of the falseness of Facebook, but stuck to someone's face.

On the other hand, it would be a godsend to those working in the service industry. Waitresses, air­hostess and concierges, among many others, would only need to paralyse the bottom half of their faces and their AgencyGlasses could give them every appearance of being cheerful.

Although it would mean that, when they finally broke a tray over an incredibly irritating diner's head, it would come as a complete surprise.

Fear gets an F for motivation

Fear can be a useful motivator. A journalist, for example, needs the dual drivers of time pressure and fear to meet deadlines. But there are downsides.

"Study or you'll fail" and "If you don't do well, you won't get into university or get a job" are common refrains heard from teachers, but new research shows that this does more harm than good.

"Teachers are desperately keen to motivate their students in the best possible way but may not be aware of how messages they communicate to students around the importance of performing well in exams can be interpreted in different ways," according to Edge Hill University's David Putwain.

His study, published by the American Psychological Association, involved about 350 male and female students and found that those who felt threatened by their teachers' messages felt less motivated and achieved poorer results than those whose teachers were not threatening.

"Psychologists who work in or with schools can help teachers consider the types of messages they use in the classroom by emphasising how their messages influence students in both positive and negative ways and by recommending they consider the messages they currently use and their possible consequences," Putwain said.

"Teachers should plan what types of messages would be the most ­effective and how they could be incorporated into the lesson plans," he said.

Exfoliating leads to true power

It would appear that carbon is the Little Chemical That Could. There's dirty, combustible coal; charcoal that can be used to purify and filter water and absorb poisons; diamonds that are not only a girl's alleged best friend but also one of the hardest materials on Earth; and graphite, the soft grey substance in pencils. And there is also graphene, in which carbon atoms are arranged in a one-layer, chicken wire-like mesh.

Researchers from China's Nanjing University of Aeronautics and Astronautics have shown that electricity can be generated by moving a droplet of sea water across a sheet of graphene. In their paper, published in the journal Nature Nanotechnology, they write: "We [have shown] that a voltage of a few millivolts can be produced by moving a droplet of sea water or ionic solution over a strip of monolayer graphene under ambient conditions [room temperature]."

It's incredible to think that, one day, maybe, in a techno-utopia, droplets of sea water moving over graphene surfaces could replace giant power stations.

Traditionally, it has been difficult to manufacture large quantities of graphene that it is defect free. (If the atoms do not make that a perfect mesh, many of its wonder-material properties are lost.)

But scientists have now devised a manageable solution, published in Nature Materials: mix graphite (the stuff in pencils) with an "exfoliating liquid" at high speed. It simplifies things to the extent that if you could get your hands on this "exfoliating liquid", technically you could make graphene at home in your blender.

Monkey three, monkey two

Mankind may be worried about computers taking over the world, and artificial intelligences turning on their human creators, but perhaps we should be more concerned about the monkeys. Researchers at Harvard Medical School claim to have shown rhesus monkeys how to count.

Published in Proceedings of the National Academy of Sciences, the research details how they taught these lab monkeys to recognise symbols and add them together in exchange for rewards.

The team, headed up by Harvard's Margaret Livingstone, taught the monkeys to memorise the numbers zero to nine, as well as 16 letters, with the incentive of food rewards.

"Given the choice of two different symbols, the monkeys chose the symbol that represented the larger reward with up to 90% accuracy, suggesting that the monkeys had learned to assign specific values to the 26 distinct abstract symbols", according to the report in the journal.

"The authors then introduced pairs of symbols that carried a reward equal to the symbols' additive value. The monkeys learned to choose the larger value, whether it was represented by a single symbol or two symbols that had to be added."

We need to find out what rewards the researchers were giving those monkeys. If television is to be believed: first, maths; then, escape and world domination. Forget candles and tinned food. We're going to need lots of those treats to placate our primate overlords.

Shrimp's killer knobkerrie

It is the Iron Man of the seas. The peacock mantis shrimp, with its flamboyant colour, may be the ocean's greatest fighting machine, and scientists are now developing materials based on the design of this 10-15cm juggernaut. "The more we study the club of this tiny crustacean, the more we realise its structure could improve so many things we use every day," says David Kisailus, chair of energy innovation at the University of California Riverside's Bourns College of Engineering. The shrimp moves the club through water at the speed of a bullet, it can strike prey thousands of times without breaking, and it moves so quickly that the club creates cavitation: boiling bubbles that implode against its prey. Also, the force with which the club bludgeons its prey is more than 1 000 times the shrimp's own weight, meaning that Kisailus and his colleagues have to keep the shrimp in special tanks.

In their research, the scientists have created a carbon composite based on the club material, and found that it was more impact resistant than the materials used in aeroplanes. "Biology has an incredible diversity of species, which can provide us with design cues and synthetic routes to the next generation of advanced materials for light-weight automobiles, aircraft and other structural applications," says Kisailus.


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