Physicists at St Andrews University, Fife, have developed a low cost laser that may greatly help security guards at airports. The laser can, according to the physicists, detect hidden explosives.

The laser device works like a robot dog nose, sniffing out minute particles that the explosives emit. As well as being great for airport security, the laser could also be ideal for detecting landmines and bombs in foreign countries such as Iran or Afghanistan.

Dr Graham Turnbull, of the research team, said: “Floating above a landmine in Iraq or Afghanistan, there’s a very weak, dilute cloud of vapours of explosive molecules that the bomb is made from.” This is what the laser detects.