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ESA's Planck mission has released its first full-sky map. The image shows the cosmic microwave background (CMB) in higher resolution than ever before and it may help cosmologists to develop a much clearer picture of the early universe. "This is the moment that Planck was conceived for," says David Southwood, who is ESA's director of science and robotic exploration. "We are opening the door to an Eldorado where scientists can seek the nuggets that will lead to deeper understanding of how our universe came to be and how it works now."

Neural networks -- collections of artificial neurons or nodes set up to behave like the neurons in the brain -- can be trained to carry out a variety of tasks, often having something to do with pattern or sequence recognition. As such, they have shown great promise in image recognition systems. Now, research coming out of the University of Hong Kong has shown that neural networks can hear as well as see. A neural network there has learned the features of sound, classifying songs into specific genres with 87 percent accuracy.

Similar networks based on auditory cortexes have been rewired for vision, so it would appear these kinds of neural networks are quite flexible in their functions. As such, it seems they could potentially be applied to all sorts of perceptual tasks in artificial intelligence systems, the possibilities of which have only begun to be explored.

By tracking the particle's motion using a video camera and then using image-analysis software to identify when the particle had rotated against the field, the researchers were able to raise the metaphorical barrier behind it by inverting the field's phase. In this way they could gradually raise the potential of the particle even though they had not imparted any energy to it directly.

"Nobody thinks of using bits to boil water," he says, "but that would in principle be possible at nanometre scales." And he speculates that molecular processes occurring in nature might already be converting information to energy in some way. "The message is that processes taking place on the nanoscale are completely different from those we are familiar with, and that information is part of that picture."

The picture was made with the Canon 5D mark II and a 400mm-lens. It consists of 1.665 full format pictures with 21.4 megapixel, which was recorded by a photo-robot in 172 minutes.

In recent years, researchers have created early versions of "invisibility cloaks" and advanced optical fibers by manipulating light using structures composed of tiny, repeating units. In the 9 April Physical Review Letters, a team proposes a different way to make an artificial optical material--from a network of light-guiding filaments. If such structures are practical, they could open new ways to control light in technologies ranging from high-speed telecommunication to high-resolution imaging.

the first negative index metamaterial to operate at visible frequencies

By engineering a metamaterial with such properties, we are opening the door to such unusual -- but potentially useful -- phenomena as superlensing (high-resolution imaging past the diffraction limit), invisibility cloaking, and the synthesis of materials index-matched to air, for potential enhancement of light collection in solar cells

A nice contrast to these high-tech installations, Adrian Lee's Search for Extra-Terrestrial Intelligence (SETI) Citrus Division (below), sees 65 lemons trying to communicate with aliens. Using their own juices, these lemon batteries power a small motor - which turns a disc into which is punched the Morse code for "We are here". As the disc rotates, a class 2 laser - also powered by the lemons - shines through the holes and the encoded message is then directed by a small mirror up into space...or in this case, onto the ceiling of the Ambica P3 venue. Amusing, simple and sophisticated all at once, the Citrus Division mixes old and new science and technology in just the right measure.

Reversible logic could cut the energy wasted by computers to zero. But significant challenges lie ahead.

By some estimates the difference between the amount of energy required to carry out a computation and the amount that today's computers actually use, is some eight orders of magnitude. Clearly, there is room for improvement.

There are one or two caveats, of course. The first is that nobody has succeeded in building a properly reversible logic gate so this work is entirely theoretical. But there are a number of computing schemes that have the potential to work like this. Thapliyal and Ranganathan point in particular to the emerging technology of quantum cellular automata and show how their approach might be applied.

equations were developed for astronomers using the Hubble telescope, Holmberg’s crew adapted them for biologists studying Earth’s biggest fishes

Holmberg also hopes that other programmers will follow his lead and lend their coding skills to worthy projects. “Pick the species or concern you’re most passionate about, pick the researchers who are working on it, and identify their technical needs,” he said. “I’m not even a great programmer. I’m underqualified but highly productive