Researchers in the US have developed a new kind of organic solar cell that converts a small but significant fraction of the sunlight that falls onto it into electricity, while still allowing most of the visible part of that light to pass through. Thanks to this transparency, the team says that the cell could be mounted onto windows in buildings or cars in order to tap a currently under-exploited source of energy.

A new experiment reported in Physical Review Letters shows that—contrary to popular wisdom—paddling can be as effective in air as it is in water. This could imply that insects evolved their flight capability from some earlier swimming trait.

Using high-speed video cameras to track wing motion, the team observed certain cases where the flies paddled their wings forward and backward. To confirm that this was indeed drag-based motion, the team plugged their wing data into an “insect flight simulator” and found that they could reproduce the fly’s overall movement. The authors constructed a simple model of paddling, which seems to support the theory that insect wings evolved in water.

This pattern of interactions matches how humans share information on social networking sites like Facebook, says the study's lead author, biologist Noa Pinter-Wollman. Most Facebook users are connected to a relatively small number of friends. A handful of users, however, have thousands of friends and act as information hubs.

computer simulations of the ants' social networks showed that information flows fastest when a small number of individuals act as information hubs. Fast-flowing information allows ant colonies to respond faster to threats such as predators and weather hazards, Pinter-Wollman says.

These well-connected ants might have an advantage in responding to threats, but they are also more vulnerable to infectious diseases, which can spread quickly through the colony.

Physicists at the Relativistic Heavy Ion Collider (RHIC) in New York say they have created nuclei of antihelium-4 for the first time – the heaviest antimatter particles ever seen on Earth.

In a Rapid Communication appearing in Physical Review A, Pengfei Zhang and colleagues at Shanxi University, China, describe experiments where they tracked an atom’s path with a spatial resolution of 100 nanometers and in a measurement time of 10 microseconds.

But not everyone is optimistic about discovering SUSY. "We will get in a crisis, I think, in a few years," Dorigo predicts, sceptical of the theory because it introduces so many new particles of which data presently show "no hints". However, even though he would lose a $1000 bet, he says that he would still be among the first celebrating if the LHC does turn up sparticles.

Like an engineer accounting for a skyscraper swaying in the wind, Madagascar's Darwin's bark spider (Caerostris darwini) spins enormous, river-spanning webs that stretch and contract as the trees to which they're anchored bend this way and that. A new study finds that this spider's silk is the toughest biomaterial yet discovered.

The spiders' colossal orb webs can span up to 2.8 square meters and are anchored by threads as long as 25 meters.

Two independent groups of physicists have built invisibility cloaks that can shield large objects lying on a plane. These "carpet cloaks" are far closer to the intuitive idea of an invisibility cloak than devices previously built, they argue, because they hide objects that can be seen with the naked eye and do so at visible wavelengths. The cloaks are also relatively cheap and easy to make, being constructed from the natural material calcite.

The team used a technique known as transformation optics to design their cloak.

Tomas Tyc of Masaryk University in the Czech Republic, who was not a member of either group, thinks that the papers "describe important achievements in the area of experimental cloaking." But he maintains that a carpet cloak is quite different to a fully fledged Harry Potter-style invisibility cloak. He points out that a carpet cloak only really works when viewing an object – be it a rucksack or a sword on someone's back, for example – side on. Otherwise the object will appear flat but still be visible.

models suggest that cut may also have cut into the warming of the state's climate in an unexpectedly big way, preventing temperatures from climbing even higher.

"This indeed has major implications for mitigating climate change on a global scale," says Ramanathan. "We have the chance to see a quick global response."