This referenced paper seems like primarily a theoretical modelling paper (almost all of its figures are simulations?) that contains as far as I can read 3 (!) actual experimental measurements in bulk on a fluorospectrophotometer. The claim is that the observed increased fluorescent quantum yield (QY) of microtubules over tubulin can be explained by the ideas in their simulations.
It's hard to buy that their proposed stories are the simplest explanation for these few measurements. Much more boring phenomena can influence QY. e.g. simply occluding fluorophores from the bulk solvent can have a huge influence on QY and spectra. (I used to design biological fluorescent reporter reagents...)
The paper itself[0] is a little (hah!) over my head, but this[1] tickled me:
> I’ve heard more than one person say that what a pity that Penrose fell for this crazy Hameroff person. But, well, I’ve met both Penrose and Hameroff and they’re both crazy of course, but neither of them is stupid.
The important thing in that paper is not "quantum", but the claim that internal data transmission by light within neural systems is a thing. The paper cites this result on ultra-weak light emissions from neurons.[1] The paper is behind Elsevier's paywall.
So the paper then takes data transmission by light as a given, and goes on to hypothesize structures that direct light as fiber optics do, and from there goes on to "ultrafast" data transmission.
Comments from biochemistry people would help here. It's not at all clear what's an actual result and what's hand-waving. However, it is clear that this is an area where experimentation is possible. Further work should move this out of the range of speculation and either confirm or dismiss it.
Given that the brain is a physical object subject to all quantum effects, wouldn’t the novelty be that it doesn't use quantum effects? That it does sounds obvious.
Words are intended to cut up the world - this is how they get their meaning. If you’ve taken these words to apply to everything in the in universe, you’ve rendered them meaningless, which is not the intention. Projectiles are subject to quantum effects but you can model their behaviour classically perfectly well. A charitable reading would be something like “to model the operational behaviour of the brain, classical mechanics is insufficient”.
I’m sorry, but your projectile example is just terrible. We’ve known for decades that the proper functioning of many (most?) enzymes depend on quantum effects. Your body would just break down otherwise.
Quantum mechanics is needed to explain any microscopic phenomena in chemistry and biology - that is not at all in dispute.
The odd set of claims is that somehow biology has 1) figured out how to preserve long-range entanglement and coherent states at 300K in a solvated environment when we struggle to do so in cold vacuum for quantum computing and 2) somehow still manages to selectively couple this to the -known- neuronal computational processes that are experimentally proven to be essential to thought and consciousness.
This more or less amounts to assertions that "biology is magic" without any substantive experimental evidence over the last thirty years that any of the above is actually happening. That's why most biophysicists and neuroscientists don't take it at all seriously.
I am a complete lay person, so I feel a bit silly challenging someone who is clearly an expert, but the idea that a physical process that has had countless trillions of generations of mutation and change, "figuring out" how to use an underlying feature of the universe to optimise, isn't far fetched at all.
It seems that the most powerful force in the universe is simply, survival of the fittest.
Yeah, a bit like when I try to lift my leg, I actually think about how to activate my neurons so that muscle fibers contract one by one...
That's definitely not what happens.
That at some level we have quantum phenomenon doesn't mean that everything occurs at the quantum level.
“Quantum effects” usually refers to coherent states of superposition. In an environment like the brain that is suffused with photons (it’s warm), if nothing else, superpositions decohere virtually instantly. It’s therefore implausible that quantum effects could play any appreciable computational role in the brain.
When these claims come up they don't mean that they are using quantum effects to do normal atomic and molecular things, but rather that somehow quantum effects are used in the process of "cognition" thus allowing us to believe that we are in fact more than biological machines and leave room for various magical properties we like to think we have (souls, consciousness, free will, etc).
While quantum effects have been found to aid in photosynthesis, interesting uses in cognition or otherwise are in fact extremely rare in biology. I believe photosynthesis is one of the few documented examples. Also, despite the popularity of the quantum brain idea, no one has been able to show definitive evidence of it for decades now.
TLDR yes it would be incredibly novel if this claim were proven to be true.
"Soul" I think is basically the memories in our brain. And memories are data, like a picture of bits some of which are on and some of which are off. Is there a picture or just random noise? If there is picture, there is soul.
Another way of thinking about it is that a picture is made up dots which are NOT lit up. So our memories, our soul is is not "physical". It does not have mass, because whether a dot is lit up or not does not change its weight. Memory is not made up of particles but by the information encoded by their positions.
Perhaps the title should have been "Brain uses Quantum effects in a useful/controllable way". Sabine explains it well in the video. To use quantum effects for computation, you'd need very controlled conditions and it was thought be to not possible in the brain.
I think -- roughly speaking -- Penrose argues that human capabilities such as transductive reasoning are clearly not computable, therefore falsifying the idea that the mind reduces to an algorithm. He then goes on to propose how nonetheless what the mind does might be physically grounded, even if not in purely computational machinery.
I think the interesting question here is whether Penrose is claiming that the things of which the brain is capable (most notably the production of consciousness) are inherently non-computable by _any_ kind of artificial device, which is effectively a form of vitalism, or whether he is claiming that they _might_ be computable, but only with a quantum computer.
In your statement, I'm not sure by which definition physically grounded things are a sufficient condition for being computable, but I think Penrose depends on the Turing notion of computability and the hardness of the halting problem.
We can of course move goal posts, redefine computability however we like, to get whatever conclusion we care for, but I think that Penrose effort is intellectually honest.
That wasn't the impression I got from Sabine's video. It's consciousness itself (the subjective experience) that isn't computable (AI will probably never be conscious).
Would you say that philosophical zombie is computable? AFAIK dualists agree that philosophical zombie is impossible in this universe, which means what is computable is a conscious being.
There are several biological processes for which we're fairly certain that some quantum mechanical process is exploited. Strictly speaking, everything about biology is ultimately explained by quantum chemistry and physics, but not in a particularly exciting way. However, I don't think anybody has found any concrete evidence that any process in biology exploits entanglement. Instead, the examples we've seen so far are mostly around tunnelling, and coherency.
People argue a lot about the "meaning of quantum" but nearly all the arguing is about the behavior of entanglement and wavefunction collapse. Tunnelling and coherency are pretty banal QM phenomena at this point.
As for Sabine... I don't find her popular science vides about biology to be particularly enlightening or accurate.
Not at all! There is evidence of quantum effects in the light harvesting complexes in chlorophyll that operate at ambient temperatures. This appears to be a key element to the efficiency of guiding photons to the photosystem.
I honestly think that mosquitoes might be already exploiting a quantum
effect while flying. For example, when you're not looking at them directly
or when they fly in a chaotic manner to avoid being seen, they seem to
disappear and reappear in different locations, traveling through
space-time.
I'm always amused by the lack of creativity of biologists.
It seems every decade or so some closely held dogma of biological systems is proven wrong after they mock physicists, computer scientists or mathematicians who first suggest it.
I suspect a lot. He has unorthodox views on lots of topics. For one he doesn't seem to believe in the heat death of the Universe. He has some interesting theories in regards to gravitational waves and so on.
> he doesn't seem to believe in the heat death of the Universe
I’m not sure I believe that the heat death of the universe really is the end of all things forever and for all time either, after reading Asimov’s The Last Question and a particularly fantastic manga oneshot adaptation by manga artist Ryul.
If you haven’t read it, I can’t recommend it more highly, and the manga version is a nice addition to the canon. I found a version narrated by the man himself on the Internet Archive, and I also found a fully voice acted audio version from the Drabblecast, also linked below.
Why is the link to this blog spam instead of to the paper or a better article? Hossenfelder lacks qualifications in neuroscience and is often confidently inaccurate.
Readit News
It's hard to buy that their proposed stories are the simplest explanation for these few measurements. Much more boring phenomena can influence QY. e.g. simply occluding fluorophores from the bulk solvent can have a huge influence on QY and spectra. (I used to design biological fluorescent reporter reagents...)
> I’ve heard more than one person say that what a pity that Penrose fell for this crazy Hameroff person. But, well, I’ve met both Penrose and Hameroff and they’re both crazy of course, but neither of them is stupid.
0: https://pubs.acs.org/doi/10.1021/acs.jpcb.3c07936
1: https://www.youtube.com/watch?v=R6G1D2UQ3gg&t=181s
So the paper then takes data transmission by light as a given, and goes on to hypothesize structures that direct light as fiber optics do, and from there goes on to "ultrafast" data transmission.
Comments from biochemistry people would help here. It's not at all clear what's an actual result and what's hand-waving. However, it is clear that this is an area where experimentation is possible. Further work should move this out of the range of speculation and either confirm or dismiss it.
[1] https://www.sciencedirect.com/science/article/abs/pii/S10111...
The odd set of claims is that somehow biology has 1) figured out how to preserve long-range entanglement and coherent states at 300K in a solvated environment when we struggle to do so in cold vacuum for quantum computing and 2) somehow still manages to selectively couple this to the -known- neuronal computational processes that are experimentally proven to be essential to thought and consciousness.
This more or less amounts to assertions that "biology is magic" without any substantive experimental evidence over the last thirty years that any of the above is actually happening. That's why most biophysicists and neuroscientists don't take it at all seriously.
It seems that the most powerful force in the universe is simply, survival of the fittest.
We haven’t even been able to reproduce abiogenesis.
That at some level we have quantum phenomenon doesn't mean that everything occurs at the quantum level.
Seems that even Nature uses abstractions.
While quantum effects have been found to aid in photosynthesis, interesting uses in cognition or otherwise are in fact extremely rare in biology. I believe photosynthesis is one of the few documented examples. Also, despite the popularity of the quantum brain idea, no one has been able to show definitive evidence of it for decades now.
TLDR yes it would be incredibly novel if this claim were proven to be true.
Another way of thinking about it is that a picture is made up dots which are NOT lit up. So our memories, our soul is is not "physical". It does not have mass, because whether a dot is lit up or not does not change its weight. Memory is not made up of particles but by the information encoded by their positions.
How would you know that when we just started studying such effects?
A chemical system is necessarily QM. Chemistry is either purely empirical, or quantum.
By which definition? Why does anything that is "physically grounded" and "achievable" be computable?
Meanwhile, I don't know what "physically grounded" and "achievable" mean in this context.
We can of course move goal posts, redefine computability however we like, to get whatever conclusion we care for, but I think that Penrose effort is intellectually honest.
There is also a theory that quantum mechanics plays a role in olfaction[1].
[1] <https://en.wikipedia.org/wiki/Vibration_theory_of_olfaction>
People argue a lot about the "meaning of quantum" but nearly all the arguing is about the behavior of entanglement and wavefunction collapse. Tunnelling and coherency are pretty banal QM phenomena at this point.
As for Sabine... I don't find her popular science vides about biology to be particularly enlightening or accurate.
It seems every decade or so some closely held dogma of biological systems is proven wrong after they mock physicists, computer scientists or mathematicians who first suggest it.
I’m not sure I believe that the heat death of the universe really is the end of all things forever and for all time either, after reading Asimov’s The Last Question and a particularly fantastic manga oneshot adaptation by manga artist Ryul.
If you haven’t read it, I can’t recommend it more highly, and the manga version is a nice addition to the canon. I found a version narrated by the man himself on the Internet Archive, and I also found a fully voice acted audio version from the Drabblecast, also linked below.
https://en.wikipedia.org/wiki/The_Last_Question
https://www.isfdb.org/cgi-bin/title.cgi?41230
Original publication:
https://archive.org/stream/Science_Fiction_Quarterly_New_Ser...
Manga version:
https://imgur.com/a/9KWrH
https://www.mangaupdates.com/series/oo67iat/the-last-questio...
https://mangadex.org/title/f1e5d886-cc50-4cbf-ac8b-6914d9343...
https://archive.org/details/manga_The_Last_Question
Audiobook versions:
https://archive.org/details/IsaacAsimovAudioBookCollection/1...
https://www.drabblecast.org/2011/03/11/drabblecast-200-the-l...