It kicked up a stink among sensory scientists when it was proposed a decade ago. Now a controversial theory that smell receptors in the nose respond to the vibration of molecules, rather than their size and shape, has been revitalised.
The theory, first proposed in the mid-1990s by Luca Turin, then of University College London (UCL), was based on the observation that some molecules with almost identical shapes can smell wildly different, while others with the same vibrational frequency, but different shapes, can smell similar. Turin proposed that the nose may work like a particular type of spectroscope that identifies…
