Rogue theory of smell gets a boost
　　1．A controversial theory of how we smell, which claims that our fine sense of odour depends on quantum mechanics, has been given the thumbs up by a team of physicists．
　　2．Calculations by researchers at University College London (UCL) show that the idea that we smell odour molecules by sensing their molecular vibrations makes sense in terms of the physics involved．
　　3．That's still some way from proving that the theory, proposed in the mid-1990s by biophysicist Luca Turin, is correct．But it should make other scientists take the idea more seriously．
　　4．"This is a big step forward," says Turin, who has now set up his own perfume company Flexitral in Virginia．He says that since he published his theory, "it has been ignored rather than criticized．"
　　5．Most scientists have assumed that our sense of smell depends on receptors in the nose detecting the shape of incoming molecules, which triggers a signal to the brain．This molecular 'lock and key' process is thought to lie behind a wide range of the body's detection systems: it is how some parts of the immune system recognise invaders, for example, and how the tongue recognizes some tastes．