Comment by periheli0n | Hacker News Reader

Comment by periheli0n | Hacker News Reader

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Ok, let's phrase it differently. In response to well-evidenced critique, raised after that 2002 book, the vibration theory of olfaction has been watered down so far that it is now arbitrary.

The wikipedia entry for the vibration theory of olfaction has plenty of links: https://en.wikipedia.org/wiki/Vibration_theory_of_olfaction?...

It didn't help the scientific debate that Turin's 2002 book contains some ad-hominem insults to scientists who had voiced challenges to his theory.

If the vibration theory has ever succeeded to uncover structure-smell relationships (like in the application with the US military that you quote), it is because the vibrational spectrum of a molecule encodes its shape and internal flexibility. It does not mean that all olfactory receptors perform spectroscopy, as Turin claimed (note the past tense - he stepped back from that claim at least 8 years ago).

3.1 Isotope effects 3.2 Explaining differences in stereoisomer scents 3.3 The sulfurous smell of boranes

Most of the critiques are debunked in the book from 1982 that I linked.

How can a book from 1982 "debunk" experimental evidence that has been obtained 20-39 years later? It cannot.

Much has happened in olfaction since 1982. A very small proportion of that work has actually debunked the vibration theory of olfaction.

It's a pity, since that theory had some very appealing properties. But it just doesn't align with the current experimental evidence.

edit: By the way, all of the observations mentioned can be explained by classical ligand-receptor interactions. No need for esoteric assumptions like spectroscopy performed by olfactory receptors.

"How can a book from 1982 "debunk" experimental evidence that has been obtained 20-39 years later? It cannot."

Well, it talks exactly about the points you mentioned and that are listed in Wiki. This book was decades ahead of its time. Seriously.

I know both sides of the argument.

There are anecdotal observations and theoretical arguments that support the vibration theory. But all aspects of it can be explained using less exotic models of ligand-receptor interaction. Proponents of the vibration theory are ignorant of those alternative explanations. The experimental evidence does not give a conclusive picture, either. Some experiments have clearly falsified aspects of the vibration theory, whereas the key experiments that support it suffer from systematic weaknesses.

Therefore, unless texperimental evidence appears that clearly supports that olfactory receptors perform electron-tunneling spectroscopy, I remain unconvinced.

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