'Quantum smell' idea gains ground
A controversial theory that the way we smell involves a quantum physics effect has received a boost, following experiments with human subjects. It challenges the notion that our sense of smell depends only on the shapes of molecules we sniff in the air. Instead, it suggests that the molecules' vibrations are responsible. A way to test it is with two molecules of the same shape, but with different vibrations. A report in PLOS ONE shows that humans can distinguish the two. Tantalizingly, the idea hints at quantum effects occurring in biological systems - an idea that is itself driving a new field of science, as the BBC feature article Are birds hijacking quantum physics? points out. But the theory - first put forward by Luca Turin, now of the Fleming Biomedical Research Sciences Centre in Greece - remains contested and divisive. The idea that molecules' shapes are the only link to their smell is well entrenched, but Dr Turin said there were holes in th...