JON CARTWRIGHT – Page 55 – & THREE QUARKS EDITORIAL

Martian grains keep on bouncing

Physics WorldJon Cartwright2 March, 2010

Published in Physics World, 2 Mar 2010

The sands of Mars are a conundrum for physicists. Both dunes and ripples of sand appear to move around on the surface, and the stuff has fallen onto the deck of NASA’s Spirit Martian rover. Yet measurements of the Martian wind suggest that it rarely gets strong enough to lift even a single grain.

Now a researcher in the US believes to have solved this apparent contradiction. “While it is very difficult for the wind to lift sand grains, once the wind does become strong enough to start blowing sand on Mars, the sand will keep bouncing, even when the wind speed drops by up to a factor of 10,” explains Jasper Kok from the University of Michigan in Ann Arbor. […]

The rest of this article is available here.

New fusion director inherits delays on ITER project

Physics WorldJon Cartwright1 March, 2010

Published in Physics World, 1 Mar 2010

The body overseeing Europe’s contributions to the ITER fusion project has appointed a new interim director amidst a further year’s delay and potential cost overruns to the 710bn experiment. Fusion for Energy (F4E) will now be led by the UK scientist Frank Briscoe following the departure of the previous director Didier Gambier last month. Briscoe has spent more than 25 years in fusion research, including managing the UK fusion experiments MAST and JET, and leading an international assessment of ITER costs last year. However, F4E says that his appointment was not made as a result of the delays, which will see construction of the reactor completed no earlier than 2019. […]

To read the rest of this article, please contact Jon Cartwright for a pdf.

Reactions on DNA origami watched with AFM

Chemistry WorldJon Cartwright28 February, 2010

Published in Chemistry World, 28 Feb 2010

Chemists in Denmark have for the first time imaged chemical reactions on a DNA origami scaffold so that they can precisely attach single molecules. Their method, which involves atomic force microscopy, will help researchers to create self-assembling DNA nanodevices for applications ranging from biosensing to drug delivery.

Although DNA itself has limited potential in chemistry, optics and electronics, its structure can serve as a template for building materials with new functional properties. For complex structures, long DNA molecules can also be folded into different shapes, known as DNA origami. The idea is that different molecules can then be attached to the origami ‘pegboard’ so composite structures become tailored, say, for conducting or optical circuits. […]

The rest of this article is available here.

Biofuels without the blend

Chemistry WorldJon Cartwright25 February, 2010

Published in Chemistry World, 25 Feb 2010

Scientists in the US have come up with a method to recycle agricultural waste into renewable alkenes for jet and diesel fuel. The breakthrough opens the door to biofuels that do not rely on special farms and that can directly replace their petroleum counterparts.

Biofuels have long been considered a promising means to reduce our dependence on oil, but traditional candidates have faced several problems. Ethanol, for instance, can be oxygenated for use in combustion engines, but only as a blend where the other 90 per cent is petrol. It is also of little use to aeroplanes, since it has such a low energy density. Finally, there is the issue of where the ethanol comes from: typically vast corn fields, which often require huge areas of deforestation. […]

The rest of this article is available here.

Ultracold magnetic atoms bode well for quantum studies

Physics WorldJon Cartwright18 February, 2010

Published in Physics World, 18 Feb 2010

Physicists in the US have for the first time trapped ultracold atoms of dysprosium, the most magnetic element in the periodic table. The breakthrough could open the door to a greater understanding of superfluidity, highly sensitive probes of magnetic fields, and new ways to read and encode quantum information.

Researchers would like to trap as many of the periodic table’s elements as possible, because the unique properties of each allow for different simulations of condensed-matter systems. The typical method involves a magneto-optical trap (MOT), in which a laser causes atoms to temporarily absorb photons and jump into an excited state. These photons give the atoms a push that, combined with the right magnetic field, is directed towards the centre of the group and keeps the atoms cooled and trapped. […]

The rest of this article is available here.

Warm white dwarfs could reveal ‘inelastic’ dark matter

Physics WorldJon Cartwright11 February, 2010

Published in Physics World, 11 Feb 2010

Direct observations of dark matter – the substance thought to account for 80% of matter in the universe – are sketchy, at best. Some experiments have found what seem like dark-matter signals, while others looking within the same parameter range have found nothing. Yet there is a hypothetical candidate for dark matter, known as “inelastic” dark matter, that could reconcile such results – and now two teams of physicists have proposed new ways to see if it exists.

The story of inelastic dark matter begins over a kilometre beneath Gran Sasso mountain in Italy, which is home to the underground DAMA experiment. Here, a bank of detectors watches out for the flash of light that is expected when a dark-matter particle strikes a nucleus within the experiment. Although such collisions are very rare, in theory there should be more flashes in summer, when the Earth is orbiting against the prevailing “wind” of dark matter in our galaxy. […]

The rest of this article is available here.

London, the ‘polycentric’ city

Physics WorldJon Cartwright3 February, 2010

Published in Physics World, 3 Feb 2010

How do commuters move around in big cities? Most people would assume that they all do pretty much the same thing: travel from the outskirts to the centre, and then back again. Yet according to a group of physicists in the UK and France, this is not the case.

“The popular conception of a city – that people work in the centre and live around the edge – is, to a certain extent, a gross simplification of what actually happens,” says Michael Batty, director of the Centre for Advanced Spatial Analysis at University College London (UCL). “The notion that one could simplify the sort of complexity that is evident is probably a non-starter.” […]

The rest of this article is available here.

Net widens for funding of arXiv

Physics WorldJon Cartwright26 January, 2010

Published in Physics World, 26 Jan 2010

Librarians at Cornell University want more external funding to support their popular arXiv preprint server because the running costs are now “beyond a single institution’s resources”.

arXiv has become the most widely used preprint server among academics in the physical sciences. It received more than 60,000 new submissions in 2009, has about 400,000 registered users and provides 2.5 million article downloads per month. Its rate of expansion is so rapid that staff expect its budget – which covers personnel as well as operating expenses – to increase from $400,000 in 2010 to $500,000 in 2012. Most of the top 25 institutional users have already made financial commitments, but to meet the budget demands Cornell Library would like several hundred others to pledge support too. […]

The rest of this article is available here.

Ions trapped by optical fields

Physics WorldJon Cartwright22 January, 2010

Published in Physics World, 22 Jan 2010

Physicists in Germany claim to have trapped single ions using lasers for the first time – an achievement that could open the door to advanced simulations of quantum systems.

In the past, the trapping of atomic particles has followed a basic rule: use radio-frequency (RF) electromagnetic fields for ions, and optical lasers for neutral particles, such as atoms. This is because RF fields can only exert electric forces on charges; try to use them on neutral particles and there’s little effect. A laser, on the other hand, can draw the dipole moments of neutral particles towards the centre of its beam. But the resultant optical trap is relatively weak, and so ions – which are sensitive to stray electric fields – easily escape. […]

The rest of this article is available here.

Down to Earth: Gadgets from outer space

New ScientistJon Cartwright18 January, 2010

Published in New Scientist, 18 Jan 2010

A space probe plunges its way through Titan’s atmosphere and lands safely on the surface. Over a billion kilometres away here on Earth, a machine fills a bag of potato crisps. Georg Koppenwallner didn’t think that Saturn’s largest moon had much in common with his favourite bar snack – at least not until he got a call from the European Space Agency (ESA).

Koppenwallner’s company Hyperschall Technologie Göttingen in Germany runs experiments in wind tunnels and calculates the aerodynamics of spacecraft, including ESA’s. This time ESA had an unusual request: could the firm’s scientists and engineers take time out from their daily grind to help find a way of packing crisps faster? Koppenwallner’s team duly obliged. Sure enough, they found a way to fill 50 per cent more bags using clever aerodynamic tricks with air pulses to speed up crisps on the production line.

It might sound strange that ESA is helping out such a decidedly non-space industry. Yet it makes good economic sense. With tens of billions of dollars spent on research every year, ESA, NASA and the Japanese space agency JAXA have access to some of the best technology and facilities in the world. That’s where Frank Salzgeber, head of ESA’s technology transfer office in Noordwijk, the Netherlands, comes in. “We make the best out of every buck the taxpayers pay,” he says. […]

The rest of this article is available here.