View Single Post
Jun20-10, 05:20 AM
Sci Advisor
P: 1,866
Quote Quote by unusualname View Post
You first said the possibility of non-trivial quantum effects in photosynthesis was BS
I did not say that. I said that it's BS to suggest that "entanglement can protect macroscopic states from decoherence". I don't even know where you got that idea.

At the same time I pointed out that quantum effects are expected when it comes to photon absorption and electron/phonon-transfer kinetics, which are wholly quantum-mechanical phenomena to begin with. Entangled states related to phonon transfer have not been observed in biochemical systems. AFAIK, nobody's looked for them either. This result was interesting because it indicates such a state (of some mechanistic significance), and makes for something which could be experimentally verified.

What would a 'trivial' quantum effect be in this case?

Anyway the main point of interest in that result is not that you have these entanglements, but rather the resulting effect that the excitations are preferentially directed to the reaction site. Some of the efficiency of the enzyme may be attributable to its utilization of non-classical dynamics for energy transfer. And that's plenty interesting in itself if you ask me.

now you're pretending your entire aggressive response was directed to my passing mention that quantum effects in the brain have previously been dismissed because of decoherence arguments (tegmark etc)
No my aggressive response was to you implying these results lend crediblity to 'quantum-conciousness' ideas.
If you're now implying that it's at odds with the Tegmark's results, that's wrong as well. Tegmark's estimates of decoherence times were on the order of 10^-13 s.

But the more important reason to dismiss large-scale quantum effects in the brain is that there is simply no reason to assume that there are any.

In my second reply I thought I'd share a fun speculative idea, just to upset you really.
So you admit you're trolling?

it's useful to know that we can learn some tricks from the superb nano-engineer that is evolution, unless of course that research I mentioned is BS.
I agree. Which is why I do quantum chemical studies of biochemical systems. And that research is not BS, and my research is not BS.
Quantum-consciousness stuff however, is BS. And I know I speak for more people in the field than just myself when I say I'm fed up with having legitimate research that happens to involve quantum mechanics and biochemical systems conflated with ideas perpetuated by a few fringe scientists and guys like Deepak Chopra.

Have you got anything interesting to say about decoherence in large systems?
Keep it cold and isolated and make sure the substance has as few degrees of freedom as possible. I.e. 'conventional wisdom' on decoherence.