Here's my guess: neurons tap into quantum mechanics but we are too primitive to understand that for now. The brain was initially modeled as humors/fluids back when we developed aqueducts, then telegraph came into the scene and it was modeled as electrical impulses and now computers/ML are popular therefore we see it as a neural network. Next step is quantum.
It's certainly not proven, but there are many hints in that direction, and the hints keep piling up. Recent research [1] on how the classic anaesthetics work (a great mystery!) suggests they operate by inhibiting the entanglement of pairs of electrons in small molecules which split into free radicals, the electrons then physically separated but still-entangled.
It seems it is at least possible, that there is speed-of-light quantum communication within the brain. And that consciousness may hinge fundamentally on this. If this is true, we're pretty much back to square one in terms of understanding.
We don't currently fully know how anesthetics work largely because we don't really know how the human brain works on a large scale. We'd have to solve that before seriously proposing quantum effects. In other words, it's too early to rule out classic physics and chemistry as the brain's primary mechanism. (Although solving how it works could first solving quantum mysteries, but Occam's razor is classic rules in my opinion.)
Chemistry is quantum physics at its core. It is just that quantum equations are so hard to solve for anything bigger than hydrogen that most of the times, chemists prefer to use empirical rules to do their job.
Einstein's spooky action at a distance, between neurons. This is speculative, maybe recklessly so, but one possible interpretation is that these are neurotransmitters. The halves of the entangled pair float off and they bind to different receptors, and do their usual neurotransmitter thing of affecting how the neuron fires. But they are entangled, so theoretically the quantum state of one half could affect the other half and alter the chemical properties of the molecule that contains the other electron. Neurotransmitters signalling through a quantum communication channel. This effect would propagate at light speed, although the subsequent chemical side of it would not.
"Spooky action at a distance" propagates at faster than light speed.
That's why Einstein thought it was spooky! But in the widespread interpretation[1] of quantum entanglement it turns out not to be a problem because (while entanglement effects are real) it's impossible to transmit information or action via it.
Worth noting that this link doesn't talk about that at all. Instead it's about quantum chemistry effects.
If the Brian is using some physics we don’t understand that’s something new not Quantum Mechanics. QM a specific theory of how the world operates, if something else is involved it doesn’t fall under that theory it’s [insert new theory’s name here].
I really don’t get why everyone wants the Brian to operate on some new QM effect other than peoples perception that a 100 year old theory is somehow cutting edge, spooky, or something. Perhaps it’s that the overwhelming majority of people who talk about QM don’t actually understand it even a little bit. Odd bits of QM are already why lasers, LED’s, and transistors work. You use incites from the theory everyday in most electronic devices, but it’s just as relevant for explaining old incandescent bulbs we just had other theories that seemed to explain them.
I think you're probably missing a number of the important details. In the Penrose/Hammerof model, they're explicitly saying that humans are observed to generate problem solutions that could not have been generated by a purely classical computing process, therefore, the brain must exploit some specific quantum phenomenon.
When you talk about QM a a theory of how the world operates, there are wide ranges of QM. Everything from predicting the structure and energy states of a molecule, to how P/N junctions work, to quantum computers. Now, for the first one (molecules), the vast majority of QM is just giving ways to compute the electron density and internuclear distances using some fairly straightforward and noncontroversial approaches.
For the other ones (P/N junctions, QC computers, etc), those involve exploiting very specific and surprising aspects of quantum theory: one of quantum tunnelling, quantum coherence, or quantum entanglement (ordered from least counterintuitive to most). We have some evidence already that there are some biological processes that exploit tunnelling and coherence, but none that demonstrate entanglement.
Personally, I think most people think the alternative to Penrose- the brain does not compute non-computable functions, and does not exploit or need to exploit any quantum phenomena (expect perhaps tunnelling) to achieve its goals.
Now, if we were to have hard evidence supporting the idea that brains use entanglement to solve problems: well, that would be pretty amazing and would upend large parts of modern biology adn technology research.
The Brian using entanglement would completely destroy modern physics as we know it, the effect on biology would be tiny by comparison.
Your other points are based on such fundamental misunderstanding that it’s hard to respond. Saying something isn’t the output of classical computing processes while undemonstrated, is then used to justify saying they must therefore use Quantum Phenomenon. But logically not everything that is either classical or Quantum so even that logical inference is unjustified. Logically it’s like saying well it’s not a soda so it must be a rock.
PS: If people where observed to solve problems that can’t be solved by classical computer processing that would be a really big deal. As in show up on Nightly News, and win people Nobel prizes big. Needless to say it hasn’t happened.
The set of problems that are computable by a classical computer are the same set of problems computable by a quantum computer. I think you might be misstating the Penrose argument/position.
I should have said "problems which do not have computable solutions" rather than "set of problems computable by a quantum computer", which seems fairly pedestrian compared to what Penrose is saying.
My understanding of the hypothesis being represented here is QM as a kind of random number generator operating at the neuron/microtubule level. I didn't think there was anything other than a modest injection of randomness being invoked, but I could be misstating the premise.
It's an absurd premise to begin with: The scale at which quantum effects propagate and are observed is radically different than the scale at which the neurons in your brain operate.
The functional channels for neurons are well understood, even if we're still diagramming out all the types of neurons. Voltage gated calcium channels are pretty damn simple in the grand scheme of things, and they don't leave space for quantum interactions beyond that of standard molecular interactions.
The only part of the brain we don't understand is how all the intricacies work together, because that's a lot more opaque.
Neurons almost certainly use quantum processes, but so do most transistors. The brain is too too warm for large-scale quantum effects though. You're not going to find phase coherence at that scale in such an environment, which is pretty much the prerequisite for quantum effects (that is fairly well understood).
I believe what was meant was quantum-only or primarily-quantum effects rather than the aggregate effects we normally see (classic physics & chemistry), which are probably the result of quantum physics, but we have "classic" abstractions that model them well enough. Thus, the issue is whether the brain relies mostly on classic effects (common aggregate abstractions) for computations or on quantum-specific effects.
I don't think that's a meaningful distinction. Many effects in classical physics are just previously poorly understood quantum effects. The distinction has more to do with when they were discovered than what causes them. Electricity is a good example. A large reason why electrons act collectively the way they do is a direct consequence of the pauli exclusion principle.
People don't understand quantum physics.
People also don't understand AGI.
Therefore it's obvious that they're related.
So it seems clear that AGI will be solved with the help of quantum physics.
My aunt Mildred is a very well renown academic and has written much on this topic.
She unfortunately is also not well understood.
So it seems quite clear - perhaps obvious - that AGI will be solved by applying some Mildred.
Because we don't understand quantum physics, and we don't understand the brain. I don't think we know if it's the final step. There could be wizard jelly or something at the bottom.
Quantum physics is fairly well understood. Perhaps not among laymen, but that's mostly due to pedagogical challenges, which is why a lot of the discourse seems to be stuck approaching it as though we were living nearly 100 years into the past.
