[Right Wing Professor]

Actually, my criticism of quantum coherence ideas in water are essentially those of Tegmark, who says coherence lifetimes in these sorts of microtubule systems should be 10^-13 s. Hameroff's argument that bound water forms part of the quantum system is specious 'Bound water' in macromolecules exchanges in and out on timescales of nanoseconds to seconds, depending on the coordination shell; exchange with free water will destroy any coherence; Brownian motion will also destroy any coherence.

Coherent excitation frequencies on the order of 10^9 to 10^11 Hz (identical to the time domain for functional protein conformational changes, and in the microwave or gigaHz spectral region) were deduced by Fr hlich who termed them acousto-conformational transitions, or coherent (pumped) phonons

This corresponds to a time scale of 10 ps - 1 ns. I have no argument with that. It is 5 - 7 orders of magnitude too short to sustain the sort of long-time coherences he needs for his theory to work.

[Alamo-Girl]

Thank you so much for your reply! Indeed, Max Tegmark is one of my favorites to watch, but in all fairness I must submit Hameroff's rebuttal to Tegmark's debunking:

The debate on decoherence - Biological feasibility of quantum states in the brain

Quantum approaches can explain enigmatic features of consciousness. However quantum coherent states must be isolated or shielded from environmental interactions and thermal noise which cause "decoherence". Critics of quantum approaches to consciousness point out that the "warm, wet and noisy" brain milieu would be particularly unfriendly to delicate quantum coherent states.

In early 1999 physicist Max Tegmark published a widely reported "refutation" of the "Penrose microtubule" model of quantum consciousness. Tegmark calculated decoherence times for microtubule quantum states (10-13 sec) which seem too fast to affect neuronal functions. An editorial in Science by Charles Seife (Cold numbers unmake quantum mind) suggested Tegmarks calculations had dealt a body blow to quantum consciousness.

However Tegmarks paper didnt address the relevant model (i.e. the Penrose-Hameroff Orch OR model) but one of his own making; he only disproved his own theoretical concoction. Physicists Scott Hagan and Jack Tuszynski and I wrote a paper using Tegmark's own decoherence formula, but correcting for stipulations of the Orch OR proposal. Our paper (Quantum computation in brain microtubules: decoherence and biological feasibility) was published in the June 2002 issue of Physical Reviews (the same journal which published Tegmarks paper) and was also selected for inclusion in the June 2002 issue of The Virtual Journal of Quantum Information. Our calculations using the actual Orch OR proposal gave microtubule decoherence times of about 10-2 to 10-1 sec, with significantly longer times possible based on topological quantum error correction effects due to microtubule structural geometry. Thus our calculations theoretically bring microtubule quantum states into a physiological realm. Recent molecular dynamic simulations of microtubules based on crystallographic structural data by Professor Tuszynskis group further support significant quantum communication.

Tegmark has been invited to debate the microtubule decoherence issue at the forthcoming conference Quantum Mind 2003: Consciousness, quantum physics and the brain but has thus far declined to acknowledge the invitation.

Here we include the abstract of our paper responding to Tegmarks decoherence paper, a link to the complete paper in PDF format, and the Science editorial by Charles Seife.