Surveillance cameras have proliferated in recent times. If you worry about low light cameras identifying you as you go out and about in the night you could try a

. The baseball cap includes LED lamps that

when seen straight on. They don't help for your daytime anonymity needs though. Or maybe you could just by an LED bulb and sew it into your favourite cap yourself.


ATTRACTIVE SOLUTION: Phosphorus is a valuable element that we need for good health, but one way and another excess phosphorus finds its way into water, including waste water systems where it becomes a pollutant. German scientists believe they can recover this valuable raw material whose reserves are being depleted. Their technique adds superparamagnetic particles to the water. If these particles detect a magnetic field they themselves become magnetic, otherwise they just float freely. The researchers added bonding sites to the particles so phosphorus attaches to them. At some point the particles can be magnetised and removed from the water, then the phosphorus can be recovered. That beats just sending it into the sea.

PICK UP NANOSTICKS: It seems about 6% of global traded goods are counterfeit, and much time is spent trying to defeat the perpetrators. Now randomly scattered silver nanowires may provide a solution. Each wire has a diameter of around 70 nanometers and an average length of 10 to 50 microns. The technique is to dump some 20 or 30 wires onto a thin plastic film, creating a tag. The outcome is a pattern that's almost impossible to replicate. Indeed, replicating the pattern could cost more than the value of the item being protected. An algorithm recognises the positions and colors of the silver nanowires and creates a database entry with a unique ID. Then an item can be quickly authenticated. The weak spot is clearly the database, and passing the IDs to and fro.

DUST DISCOVERIES: You and I might carelessly brush away a speck of dust, but the 7 particles the Stardust spacecraft collected between 2000 and 2002 must be some of the most precious on the planet. Stardust used blocks of aerogel to collect interstellar particles, but then the problem was how to find the particles inside the gel. The team had members of the public examine microscopic images to pick out the telltale tracks left by speeding particles, ultimately locating 7 that weighed trillionths of a gram each. Now the team need to actually analyse those specks of dust, without losing or destroying them. All in all a very delicate operation.

HIDE THE LIGHT: The problem with actually seeing the planets that orbit other stars is that the light of the star far outshines any light from the planet itself. That's where NASA's flower-shaped PlanetQuest starshade comes in. It's designed to work in conjunction with a space-based telescope, positioning itself precisely between the telescope and the star that's being observed, blocking the starlight before it reaches the telescope's mirrors. That way any light from an exoplanet could be observed, making photos possible. The starshade is shaped like the petals of a flower to soften the edges and reduce the bending of light waves. But aren't there a lot of other stars whose light would interfere too?

Miraz Jordan,