Yes, we do understand quantum mechanics very, very well. It is a profoundly reliable theory, and fully describes all phenomena that could plausibly have causal effects on biochemistry. You have to get to black holes, galaxy formation, or femtokelvin above absolute zero to encounter regions where the standard model breaks down / new physics becomes possible.
Regarding critical evaluations of Penrose, this is the first that pops up: https://physicsworld.com/a/quantum-theory-of-consciousness-p... Like most published accounts, it is respectful towards Penrose and less inflammatory than what I wrote, at least on the surface. I'd draw your attention to this bit towards the end though:
> Still, they say, the overall requirements seem daunting – the brain needing to maintain a mass of 10−16 kg in a coherent state for 25 ms over a length scale of about 10 nm. “This vastly exceeds any of the coherent superposition states achieved with state-of-the-art optomechanics or macromolecular interference experiments,” they note.
This is a devastating statement hidden in technical terminology. Basically he's saying: "Even with the most sophisticated physics laboratories, under ideal conditions & with highly sensitive instrumentation, we're unable to achieve the superpositions that Roger Penrose is claiming is going on in the absolutely hostile thermal bath of the brain."
Regarding critical evaluations of Penrose, this is the first that pops up: https://physicsworld.com/a/quantum-theory-of-consciousness-p... Like most published accounts, it is respectful towards Penrose and less inflammatory than what I wrote, at least on the surface. I'd draw your attention to this bit towards the end though:
> Still, they say, the overall requirements seem daunting – the brain needing to maintain a mass of 10−16 kg in a coherent state for 25 ms over a length scale of about 10 nm. “This vastly exceeds any of the coherent superposition states achieved with state-of-the-art optomechanics or macromolecular interference experiments,” they note.
This is a devastating statement hidden in technical terminology. Basically he's saying: "Even with the most sophisticated physics laboratories, under ideal conditions & with highly sensitive instrumentation, we're unable to achieve the superpositions that Roger Penrose is claiming is going on in the absolutely hostile thermal bath of the brain."