JON CARTWRIGHT – Page 48 – & THREE QUARKS EDITORIAL

Lasers could nudge space debris aside

NatureJon Cartwright15 March, 2011

Published in Nature, 15 Mar 2011

Scientists in the United States have devised a new way to avoid collisions among space debris, and possibly even reduce the amount of debris in orbit. The method uses a medium-powered, ground-based laser to nudge the debris off course — but some are concerned that the laser could be used as a weapon.

Debris orbiting Earth is a mounting problem. Two years ago, a satellite owned by the communications provider Iridium, based in McLean, Virginia, smashed into a defunct Russian satellite at ten times the speed of a rifle bullet, putting an end to the ‘big sky’ theory that assumed space was too vast for chance collisions. That incident alone created more than 1,700 pieces of debris, raising the total amount by nearly 20%. […]

The rest of this article is available here.

The battle to find Maxwell’s perfect image

Physics WorldJon Cartwright9 March, 2011

Published in Physics World, 9 Mar 2011

To make a perfect lens – one that produces images at unlimited resolution – you need a very special material that exhibits “negative refraction”. Or so researchers had thought.

Now scientists in the UK and Singapore have published experimental evidence that shows perfect lenses don’t need negative refraction at all – and that a simpler solution lies in a 150 year-old design pioneered by James Maxwell. If true, the discovery could be a goldmine for the computer-chip industry, allowing electronic circuits to be made far more complex than those of today. However, the work is proving so controversial that the lead scientist has become embroiled in a fiery debate with other experts in the field. […]

The rest of this article is available here.

Carbon nanotubes – a boon for chiral catalysts

Chemistry WorldJon Cartwright8 March, 2011

Published in Chemistry World, 8 Mar 2011

Researchers in China have created a new catalyst that could help in the production of ‘chiral’ molecules for medical drugs. The catalyst, which consists of platinum nanoparticles encapsulated in carbon nanotubes, is the most active of its type ever reported, they say.

A chiral molecule is asymmetric – not symmetrical – in such a way that its mirror image cannot be super-imposed on itself. Although a chiral molecule’s two manifestations, known as ‘enantiomers’, (the molecule and its mirror opposite) are often produced in reactions in equal quantities, they can have different properties. In medicine, one enantiomer can be more effective than the other, and researchers are keen to find ways to encourage production of single enantiomers, rather than mixtures. […]

The rest of this article is available here.

Memristors Make Fast Work of Mazes

ScienceJon Cartwright7 March, 2011

Published in ScienceNOW, 7 Mar 2011

For some, mazes are a way to idle away a few spare minutes or a way to get lost among the hedges of country gardens. Yet maze solving has more serious uses, such as helping robots navigate or planning better routes for traffic. Now such applications could benefit from what two U.S. researchers say is the best maze-solving method yet—and it all rests on a simple electrical circuit and an unusual device called a memristor.

In the past, researchers have tried various ways to solve mazes. They include the slow but simple “random mouse” method, which involves taking a random left-or-right decision at every junction and wandering aimlessly until the exit is found, and mathematical algorithms that analyze each possible route. Last year, a group from Northwestern University in Evanston, Illinois, showed that even simple oil droplets could navigate mazes, so long as they were driven by chemicals placed at the end. […]

The rest of this article is available here.

Earth’s missing xenon could be hiding in quartz

Chemistry WorldJon Cartwright1 March, 2011

Published in Chemistry World, 1 Mar 2011

What’s happened to the Earth’s missing xenon? For decades scientists have known that the abundance of xenon is curiously lower than predicted from comparisons with the other noble gases. Yet they have been unable to determine why. Now chemists in Canada have evidence that it is residing in the ground beneath our feet.

Some of the first hints of the anomaly came in the 1970s, when scientists found that xenon is about 20 times less abundant in our atmosphere than other noble gases – even though studies of meteorites suggested its general abundance in the Solar System should be roughly the same. Theories abounded: maybe the xenon has been lost into space, or frozen into the ice caps, or trapped inside sedimentary rock. But calculations showed that these processes could account for at best one-fifth of the missing gas. […]

The rest of this article is available here.

The great sound escape

New ScientistJon Cartwright26 February, 2011

Published in New Scientist, 26 Feb 2011

Urban life is a barrage of thumping bass lines and blaring horns. Is there any way to silence the din? Jon Cartwright goes in search of a good night’s sleep

IT IS 3 am. Thud, thud, thud go the footsteps up the stairs. Uh-oh. Sure enough, laughter and music are soon pouring through the ceiling. Even with my head buried under the pillow, bass notes pound through my skull. Eventually I drop off, only to be woken a few hours later by revving engines as the rush hour begins.

Being kept awake by noisy neighbours and traffic is maddening. It is not just the mounting resentment that your personal space is being compromised and the stress of trying to deal with it: chronic noise pollution can seriously damage your health too, and it is a growing problem. […]

The rest of this article is available here.

Insect antennae inspire responsive nanopores

Chemistry WorldJon Cartwright20 February, 2011

Published in Chemistry World, 20 Feb 2011

Researchers in the US have created nanopores that can capture, concentrate and shift molecules in predictable ways. The development – inspired by the waxy coating on insect antennae – could help to characterise proteins and membranes for therapeutic drugs.

Nanopores are a type of sensor used for detecting nanoscale objects such as single proteins, DNA and the molecules involved in chemical and biological reactions. Unlike ‘bulk’ sensors, nanopores enable scientists to see static and dynamic variations that would otherwise be lost among numerous other processes. Several teams are working towards nanopore systems that can sequence individual DNA molecules. […]

The rest of this article is available here.

Spinning black holes twist light

Physics WorldJon Cartwright15 February, 2011

Published in Physics World, 15 Feb 2011

Light passing near to the spinning black holes thought to reside at the centre of many galaxies becomes twisted, possibly offering a new way to test Einstein’s general theory of relativity. That is the conclusion of an international team of physicists, who say the phenomenon could be seen with existing telescopes.

The general theory of relativity (GR), put forward by Einstein more than 90 years ago, predicts few phenomena that can be easily tested. One example is gravitational lensing – that the gravity of stars and black holes can warp space–time enough to bend the passage of light. Another is time dilation, which makes clocks sitting in regions of lower gravity – say, at high altitudes – tick faster. Scientists are still trying to directly detect yet another general-relativity phenomenon called gravitational waves. These are ripples in space–time thought to be generated when large masses accelerate. […]

The rest of this article is available here.

Worms’ diet the key to coloured silk

Chemistry WorldJon Cartwright15 February, 2011

Published in Chemistry World, 15 Feb 2011

Scientists in Singapore have found out how to produce coloured silk based on the diet fed to silkworms. The discovery has the potential to end the expensive and environmentally harmful methods currently used to dye silk fibres, and could also pave the way for luminescent silk scaffolds for use in medicine.

Ming-Yong Han of the Agency for Science, Technology and Research and colleagues have fed silkworms various dyes, and examined the molecular take-up with fluorescence imaging and spectroscopic quantification. […]

The rest of this article is available here.

Outcast Planets Could Support Life

ScienceJon Cartwright11 February, 2011

Published in ScienceNOW, 11 Feb 2011

If aliens exist, where are they? Many astronomers look to the nearest stars, in the hope that they harbor a warm, wet planet like Earth. But now a pair of researchers believe extraterrestrial life could exist on a rogue planet that has been ejected from its birthplace.

Astronomers have never spotted a rogue planet with certainty, but computer simulations suggest that our galaxy could be teeming with them. Slingshotted out of their planetary system by the gravity of a bigger planet, these lone worlds zoom far from their parent suns, slowly freezing in the cold of outer space. Any water fit for life would freeze, too. Yet in a paper submitted to The Astrophysical Journal Letters, planetary scientists Dorian Abbot and Eric Switzer of the University of Chicago in Illinois suggest that a rogue planet could support a hidden ocean under its blanket of ice, kept warm by geothermal activity. […]

The rest of this article is available here.