Luca Turin talks… 'Is Smell a Quantum Phenomenon?'

Luca Turin – esteemed fragrance critic, writer, scientist and all-round notoriously knowledgable character – presented a fascinating talk in congunction with The British Society of Perfumers and The Royal Society of Chemistry. Prefacing the talk by explaining a little more of the vibrational theory of scent – a theory he has spent years investigating, and later led to his continuing career as a fragrance critic and scent expert, Luca explained:
‘Our sense of smell is extraordinarily good at molecular recognition – we can identify tens of thousands of odorants unerringly over a wide concentration range. The mechanism by which this happens is still hotly debated. One view is that molecular shape governs smell, but this notion has turned out to have very little predictive power. Some years ago I revived a discredited theory that posits instead that the nose is a vibrational spectroscope, and proposed a possible underlying mechanism, inelastic electron tunnelling. In my talk I will review the history and salient facts of this problem and describe some recent experiments both on fruit flies and on humans that go some way towards settling the question.’
In 2005, Turin presented a TED talk on The Science of Scent, which you can watch by clicking the video, below…

Having greatly expanded his research methods and been excited at the findings, Turin explained the main impetus behind his interest in the subject was simply wondering why certain things smell the way they do – how is odor written into a molecule? – with the more traditional ‘shape’ theory (which supposes all odor molecules are differing shapes so ‘fit’ certain receptors in the humn nose and not others) just didn’t explain it all satisfactorily. The Vibration Theory of Olfacation (as it is catchily known) proposes that a molecule’s smell character is due to its vibrational frequency in the infrared range. As an alternative to the more widely accepted shape theory of olfaction, which proposes that a molecule’s smell character is due to its particular molecular size, shape and functional group, it has been termed ‘contraversial’ – though Turin loathes the word and thinks it’s almost meaningless in the context of scientific research.
In the wood-panelled library, before a packed audience of scientists, chemists, biologists and many fragrance-loving knowledge-junkies and Turin fans, too; it was clear how truly passionate Luca Turin is about this subject. As one of the very few scientists able to fully explain his reasonings – never patronising his audience but allowing them to share his enthusiasm – it was such a privillege to hear him speak (even though we admit our heads hurt a little bit – in a pleasurable way! – at the end of it).
The British Society of Perfumers are hoping to open up a lot more talks and workshops to interested members of the public and guests in furture, and this we wholeheartedly applaud. Have a look at their website to see forthcoming events you might be interested in attending…
Written by Suzy Nightingale
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