Many years ago over some German beers and Magic the Gathering cards my physicist friend and I discussed the possibility that the mind is quantum given the close-ish proximity between neurons.

Neuron's heads have a gap of 20-40nm and the side-by-side distance between cells is similar around 15-100nm. This is just slightly beyond the typical distance where quantum effects dominate (<10nm). Thats why our CPU transistors have been getting quite problematic as we've been pushing into the single digit nanometers.

Quantum tunneling occurs when an electron probability cloud overlaps a particle nearby and appears to disappear from one particle and joins the second particle instead. It's different than a chemical bond because the electron is transiting "through" Hilbert space, which really only exists in probability math land. When that occurs in a transistor its a bad bit flip. But maybe in our brains it's an insight?

The transmission probability of a particle attempting to tunnel through a potential energy barrier (empty space) drops off exponentially with distance. So at 5nm thats around 1 in a million but at 15nm its 1 in a quintillion, so a trillion times less likely. But, we mused drunkenly, maybe theres some other effect that inches it up a bit more that isn't yet known resulting in occasional quantum effects occurring...

Since then I hadn't done any further investigation on the subject. Until today when I stumbled upon the idea of Quantum Biology in a deep research AI query. Turns out a Nobel Laureate physicist named Sir Roger Penrose came up with a hypothesis called "Orchestrated Objective Reduction" which postulates that quantum computation is occurring within neuron microtubules, plenty small for such effects.

Here's the core ideas summarized by AI/wikipedia:

Thesis: Consciousness originates from non-computable quantum processes inside neurons, not classical synaptic computation.

Quantum Superposition: Tubulin protein dimers within microtubules contain hydrophobic pockets. Delocalized pi-electrons within these pockets act as qubits, entering quantum superposition.

Orchestration ("Orch"): Synaptic inputs and Microtubule-Associated Proteins (MAPs) isolate, tune, and organize these fragile quantum states.

Objective Reduction ("OR"): Wave function collapse is not random. It is a deterministic physical mechanism triggered by fundamental spacetime geometry (quantum gravity). Collapse triggers when gravitational self-energy of the superposition reaches a critical threshold.

Output: Each discrete collapse produces a singular "moment" of conscious awareness.

Primary Barrier (Decoherence): Classical physics dictates the brain is too "warm, wet, and noisy" to sustain quantum coherence. Max Tegmark (2000) calculated decoherence would occur at $10^{-13}$ seconds—too rapid to influence neural firing.

Current Evidence: Hydrophobic microtubule interiors theoretically shield quantum states from thermal noise, extending coherence times. Recent anesthesiology data (e.g., experiments involving Xenon isotope nuclear spin) indicates anesthetics directly dampen quantum dipole oscillations inside microtubules, establishing a causal physical link between quantum suppression and the loss of consciousness.

If true this would be highly controversial. People have said the brain is far too warm & wet to sustain fragile quantum superpositions. So Sir Penrose is directly contradicting established decoherence models.

Penrose argues that these tubulins and the surrounding water physically shield the quantum states from the brain's thermal noise just long enough for the gravitational collapse threshold. Also this hypothesis requires Quantum Gravity (an unverified unification of general relativity and quantum mechanics) to bypass the need for a conscious "observer" to collapse a wave function.

But for now that is another rabbit hole I won't be going down tonight. Maybe someone here will dig in more. Seems like there could be applications to cognition, quantum computers, and perhaps physics in general if true!