Our brains use angular measurements to decide how far away objects are.

Even if trigonometry wasn’t your strong suit in school, your brain uses it constantly. You judge distance by measuring the angle between the ground and your line of sight to an object, a new study shows. The finding could improve the design of robots and artificial vision systems 1 .

Volunteers who looked through prisms that increased this angle thought objects were closer than they reall

New catalyst means greener paper is not pulp fiction.

Pollution from paper production could be cut, say US chemists, with a new way of refining wood pulp 1 . But the process must go through the mill before it can convert industry.

During paper production, gluey wood component lignin is stripped out to leave stringy cellulose. The harsh chemicals used create environmental pollutants, such as toxic and long-lasting chlorinated compounds.

A new chemical

Scientists are finally beginning to understand how common genetic differences among individuals underlie differences in the structures that make up their brains. In the first attempt to actually map these variations, neurologist Paul Thompson and colleagues at the University of California at Los Angeles have discovered that brain structures related to cognitive ability and language seem to be under tight genetic control. The group’s findings, which could help explain how diseases like schizophre

Air lets water droplets skim across the kitchen sink.

Scientists have found the answer to a question pondered over many a kitchen sink: why do little droplets skim across the surface of washing-up water rather than mix with it?

Yacine Amarouchene and colleagues at the University of Bordeaux in Talence, France have discovered that the height from which the drops fall has no effect on their lifespan 1 .

Soap, detergent – and indeed food grease – are ’

A microelectronic sensor may alert doctors to bacterial hazards.

Smart bandages could soon alert doctors to the presence of certain bacteria in a wound by glowing different colours. Researchers in the United States have created a tiny device that emits faint light of two colours in response to two types of bug 1 .

Benjamin Miller, of the University of Rochester in New York State, and colleagues hope that a refined sensor might ultimately generate an instant an

Solar cells printed like wallpaper.

Solar cells might one day be produced by the roll, as cheaply and easily as wallpaper. Scientists in Arizona are using screen-printing, a technique developed for patterning fabrics, to produce plastic solar cells 1 .

The technique is another step towards the general availability of solar power from flexible devices on plastic sheets or glass panels. The basic materials of a photovoltaic cell are inexpensive, but combining t