Undermines· moderateORCH-E007
Tegmark: microtubule decoherence 10⁻¹³–10⁻²⁰ s, far too fast for neural relevance
- what the source states
- The abstract reports calculated decoherence timescales for superposed neural states — specifically "for superpositions of neuron firing (coherent or not)" and "for either separated coherent states of a single tubulin or for two tubulins in the same state" — in the range 10⁻¹³ to 10⁻²⁰ seconds, against dynamical timescales of neural processes of 10⁻³ to 10⁻¹ seconds. The conclusion drawn is that "the degrees of freedom of the human brain that relate to cognitive processes should be thought of as a classical rather than quantum system."
- what we infer
- For twenty-five years this has been the reason most neuroscientists considered the question closed, and the gap it reports — ten to seventeen orders of magnitude — is large enough that no amount of refinement at the margins would close it. Its evidential status should be stated plainly though: it is a calculation about a modeled state, not a measurement of a microtubule, and its force depends entirely on whether the state it modeled is the state the theory proposes. That is precisely what the Hagan reply contests, which is why this is graded moderate rather than strong.
- limitations
- A theoretical calculation, not a measurement; no microtubule was observed.
- Models specific superposed states whose correspondence to the Orch OR proposal is disputed by Hagan et al. 2002.
- Predates the ordered-lattice and collective-state work of 2023–2024, which changes some of the assumed environment.
- Assumes environmental coupling parameters that the proponent reply argues are inappropriate for ordered biological structures.