[bascule]

This article covered more than I was expecting, but still manages to squeeze a small amount of substance into a relatively large article. Here's a tl;dr:

- Penrose and Hameroff postulate microtubules might have quantum mechanical behavior in their Orch-OR hypothesis. This hypothesis was refuted by Max Tegmark in the 90s. Penrose doesn't care and keeps preaching his hypothesis, and has not put forth any new scientifically compelling arguments in the past 2 decades.

- Photosynthesis is shown to be quantum mechanical. I'm not sure quantum mechanical behavior in plants is the best argument that quantum mechanics are responsible for consciousness.

- Fischer hypothesizes that phosphate ions in biological cells might exhibit distinctly quantum mechanical behavior, but is wary about any link to "quantum consciousness".

This is pretty much all of the substance of the article.

Even if there were a conclusively demonstrated link between quantum mechanical behavior in human cells (there isn't), using that to argue that our brains are quantum computers and that consciousness is a fundamentally quantum phenomenon would be a huge non sequitur.

[mannykannot]

Furthermore: "Photosynthesis is shown to be quantum mechanical" - well, yes, just like everything else in physics, with the possible exception of those issues, like black holes, where gravity is dominant. The quantum-mechanical basis of chemistry has been included in high-school chemistry curricula for at least half a century, so it would be quite remarkable if photosynthesis were a exception.

While it is possible that the human mind has no classical-approximation explanation, the equating-of-ignorance argument, stated in the article's subtitle, is no reason to think it is so (and quantum mechanics is much better understood than the human mind, anyway.)

[thraway180306]

All chemistry is ultimately quantum, same with rocks and everything up to celestial bodies (meaningfully, the moon Hyperion decoheres). For most of calculations though classical models are good enough, vast majority of chemical reactions behave as if molecules were newtonian springs. When people talk of quantum effects in chemistry they really mean it. In case of photosynthesis the basic molecule's efficiency was found hinging on stuff that is very quantum. This was described by Gregory Engel et al. Alan Aspuru-Guzik interprets some of what's happening as a realization of quantum computation running a tree-walking algorithm.

The wider conclusion is that living organisms do evolve around quantum effects (if the molecule existed a priori somehow) or maybe even evolve to the point of reaching and then harnessing them (making the molecule).

Now to what's Penrose about. Seldom anybody actually reads the guy or know the context. He was after the computational theory of mind. Not necessarily looking for a theory, but sneering at one big non-theory. This is in context of the 80's with unhinged stuff coming from the AI community (same as today). He was wondering if brain could really be this reducible and a known model of computation (he hasn't done a good review) from the physical point of view. For him a full logical reductionism necessiated excissing the measurement problem (the basic point goes back to Niels Bohr who thought biology cannot be entirely physics because of this). So he proposed a crude version that fleshes out measurement as a real physical process. His idea has the main upside of removing both quantum and AI mysticism.

This received angry and mostly off-topic response based on caricature summaries like elsewhere in this thread. Of course lending themselves to such caricatures says a lot about writing if not the ideas, but it's an honest try that ain't entirely silly and without upsides. The microtubules guy is someone else who Penrose was just happy to see come and collaborate with later. He'd be happy with any kind of other stuff, such as from the original article. BTW the author is Philip Ball, a long time editor of the Nature journals, and he's got a new book out about interpretations of quantum mechanics that is really superb to anything else on the market by far (that is could be better but isn't worthless).

[adrianN]

My problem with his theory is not that consciousness in the brain might be dependent on quantum effects, but that he seems to conclude that this makes it impossible for computers to have consciousness. Quantum computers can be simulated by classical computers.

[thraway180306]

That's a significant goalpost move. From debating particular mechanisms and postulated inevitability of AI, to assuming full blown strong Church-Turing-Deutsch principle and moving from there. Along with moving whole discussion from practical concerns into philosophy and really arguing from the thesis, at which point most people lose interest.

[jungletime]

Somewhat related, Giulio Tononi on his theory of consciousness and why computers can't have consciousness.

https://youtu.be/eskWYOH-Oxs?t=270

Starts at 4:34

[lloeki]

> Hyperion decoheres

Fascinating!

http://blogs.discovermagazine.com/cosmicvariance/2008/10/23/...

[noetic_techy]

They are referring to the finding that plants utilize coherence to transport photons efficiently to reaction centers to be converted to chemical energy. A quantum trick not thought possible in biological settings.

https://www.bbc.com/news/science-environment-22996054

[mannykannot]

My issue is with how the author is using this fact as if it were an argument for the proposition that consciousness cannot be explained without invoking quantum 'weirdness' (and, conversely, will be explained with it.)

The way the author presents it seems calculated to suggest that it is a more relevant fact to his claim than it is, mainly by leaving out any context and details that show it is not.

This is not even the worst case, which I think goes to this: "Might it be that, just as quantum objects can apparently be in two places at once, so a quantum brain can hold onto two mutually-exclusive ideas at the same time?"

Note how the author phrases it in a way that would allow him to brush it off as mere speculation or analogy if he is challenged on it - a case of the motte-and-bailey tactic. I think this passage qualifies as being "not even wrong", and the whole article clearly fits Feynman's definition of cargo-cult 'science'.

Meanwhile, I have a computer that can do two tasks at the same time - does that mean that it is a quantum computer? I see D-Wave is selling quantum computers for upwards of $15M, but mine is available with bids starting at a mere $5M.

[noetic_techy]

I completely agree. It was by and large a very good article, but could have been better if it presented the other side. I'd like to know what the counter evidence is. The author seems to imply that the other side is "in the dark" on this question, and has no hypothesis and speculation of their own.

[SubiculumCode]

What do you think of this paper?

Nuclear Spin Attenuates the Anesthetic Potency of Xenon Isotopes in Mice: Implications for the Mechanisms of Anesthesia and Consciousness.

Xenon is an elemental anesthetic with nine stable isotopes. Nuclear spin is a quantum property which may differ among isotopes. Xenon 131 (Xe) has nuclear spin of 3/2, xenon 129 (Xe) a nuclear spin of 1/2, and the other seven isotopes have no nuclear spin. This study was aimed to explore the effect of nuclear spin on xenon anesthetic potency.

CONCLUSIONS: Xenon isotopes with nuclear spin are less potent than those without, and polarizability cannot account for the difference. The lower anesthetic potency of Xe may be the result of it participating in conscious processing and therefore partially antagonizing its own anesthetic potency. Nuclear spin is a quantum property, and our results are consistent with theories that implicate quantum mechanisms in consciousness.

https://www.ncbi.nlm.nih.gov/pubmed/29642079

[GorgeRonde]

This paper describes the effect of Xenon on plants:

"Anaesthetics stop diverse plant organ movements, affect endocytic vesicle recycling and ROS homeostasis, and block action potentials in Venus flytraps"

> Xenon was effective at different levels of responses, such as seed germination, chlorophyll accumulation, ROS production and vesicle recycling.

> Plant sensitivity to anaesthetics might help to reveal elusive mechanisms of their actions. It is puzzling how such chemically and physically diverse compounds, including the chemically inert gas xenon, the volatile organic solvent ether and water-soluble molecule such as lidocaine, can induce very similar impacts in both plants and animals.

Source: https://flore.unifi.it/retrieve/handle/2158/1111827/295556/m...

[selimthegrim]

There’s probably some effect on the vibrational or Raman spectrum, sounds like the sort of thing this guy would study

http://www.cce.caltech.edu/people/daniel-p-dan-weitekamp

[Nasrudith]

Photosynthesis as an argument is more 'it is possible that quantum effects have a place here' - that said it is a long leap given that our retinas are technically quantum just by processing particle-wave dualities. The quantum /computing/ is what is relevant to proof of there being any 'special sauce' to the human brain vs just a bunch of parallel processing power.

Essentially the quantum effects are necessary for a quantum consciousness but are definitely not sufficient. Personally I can see one way to make that link which is quite a long-shot.

Given what little I know from quantum computing and cryptography comparing parallel processing solving speed relative to problem sizes vs quantum approaches would give a theoretical basis for distinguishing the /computing/ aspects.

If human brains are able to solve progressive problems with a time increase more consistent with qubit processing than non-quantum computing combined with heuristics it would hint at quantum processing power. Needless to say that is a major tall order and would probably result in most humans failing to complete period.

[Jipazgqmnm]

Non sequitur? It's like writing: I ate a salty sandwich, hence I behave like a NaCl crystal. Or when I roll the dice careful enough, it gets deterministic. Hence the hole world is deterministic.

I think you can politely call it nonsense.

[hyperpape]

Pretty much. I forget who is responsible for providing it, but one summary of the Penrose argument is:

1. Quantum mechanics is weird and confusing.

2. Consciousness is weird and confusing.

3. Therefore, quantum mechanics probably explains consciousness.

[Marazan]

That's basically everyone's summary of the Penrose argument about consciousness and quantum effects. I don't think you can ascribe it to any one person.

The summary his argument against hard question AI is even better. Human consciousness is special. Computers don't have that specialness. AI is therfore impossible.

[coldtea]

Or, you know, he probes (even if without results) for things we consider "done and closed" or "needless", so we reduce any argument he makes to a huge strawman.

[EGreg]

Actually that is how pilot wave theory is explained.

You have a deterministic world, you just think it's random because you don't have enough knowledge of how everything is going to work.

[pknight]

> This hypothesis was refuted by Max Tegmark in the 90s.

No it wasn't and Tegmarks earlier criticisms were proven fundamentally flawed. What scientifically compelling arguments has Tegmark produced for his theories?

[GorgeRonde]

> - Photosynthesis is shown to be quantum mechanical. I'm not sure quantum mechanical behavior in plants is the best argument that quantum mechanics are responsible for consciousness.

--------------------------------------------------------

"Something Really Fascinating Happens When You Give Plants Anaesthetic"

> While there's a range of chemicals that can induce anaesthesia in humans, just how these unrelated compounds trigger a lack of consciousness remains somewhat unclear.

> And the mystery deepens when you consider it isn't only animals that are affected by anaesthetics – plants are, too.

...

> "That animals/humans and also plants are animated via action potentials is of great importance for our ultimate understanding of the elusive nature of plant movements and plant-specific cognition/intelligence based plant behaviour."

> Ultimately, the team thinks these similarities between plant and animal reactions to anaesthetic compounds could lead to future research where plants might function as a substitute model or test system to explore human anaesthesia – something scientists are still pretty uncertain about.

Source: https://www.sciencealert.com/plants-respond-anaesthetics-wei...

--------------------------------------------------------

Now if I had to add a philosophical icing to the cake, I'd guess once something gets to complicated to be explained from the ground up as a consistent whole, the only way to get at it is to study what causes this whole to cease.

[perl4ever]

I think "lack of consciousness" is not a well-defined concept. Popular forms of anesthesia these days result in what appears to be a more or less conscious patient in one sense, who can respond to some stimuli, but who does not form memories or feel pain. So in retropect, when the procedure is over, it's as if it never happened. But any observer can see they weren't unconscious as in dreamless sleep.

The point being, there are many components to what we call consciousness that seem to be demonstrably separable and it doesn't help to talk as though it's all just one unified whole.

[deepnotderp]

Tegmark's criticisms were actually shown to be wrong

[SubiculumCode]

citation?

[coldtea]

>This article covered more than I was expecting, but still manages to squeeze a small amount of substance into a relatively large article. Here's a tl;dr: - Penrose and Hameroff postulate microtubules might have quantum mechanical behavior in their Orch-OR hypothesis. This hypothesis was refuted by Max Tegmark in the 90s. Penrose doesn't care and keeps preaching his hypothesis, and has not put forth any new scientifically compelling arguments in the past 2 decades.

"Doesn't care" as in la-la-la hands-in-the-ears, or doesn't care as in, believes the refutation is not valid, or believes that despite the refutation of that particular mechanism there's enough evidence that there's another related mechanism?

Here's how Wikipedia puts it, which is not at all as "Tegmark won", but rather like "Tagmark's claims were wrong themselves, and refuted further":

In response to Tegmark's claims, Hagan, Tuszynski and Hameroff[56][57] claimed that Tegmark did not address the Orch-OR model, but instead a model of his own construction. This involved superpositions of quanta separated by 24 nm rather than the much smaller separations stipulated for Orch-OR. As a result, Hameroff's group claimed a decoherence time seven orders of magnitude greater than Tegmark's, although still far below 25 ms. Hameroff's group also suggested that the Debye layer of counterions could screen thermal fluctuations, and that the surrounding actin gel might enhance the ordering of water, further screening noise. They also suggested that incoherent metabolic energy could further order water, and finally that the configuration of the microtubule lattice might be suitable for quantum error correction, a means of resisting quantum decoherence.

Since the 1990s numerous counter-observations to the "warm, wet and noisy" argument existed at ambient temperatures, in vitro[23][42] and in vivo (i.e. photosynthesis, bird navigation). For example, Harvard researchers achieved quantum states lasting for 2 sec at room temperatures using diamonds.[58][59] Plants routinely use quantum-coherent electron transport at ambient temperatures in photosynthesis.[60] In 2014, researchers used theoretical quantum biophysics and computer simulations to analyze quantum coherence among tryptophan π resonance rings in tubulin. They claimed that quantum dipole coupling among tryptophan π resonance clouds, mediated by exciton hopping or Forster resonance energy transfer (FRET) across the tubulin protein are plausible.[61]

In 2007, Gregory S. Engel, Professor in Chemistry at The University of Chicago, claimed that all arguments concerning the brain being "too warm and wet" have been dispelled, as multiple "warm and wet" quantum processes have been discovered.[60][62]

In 2009, Reimers et al. and McKemmish et al., published critical assessments.[19][37][45] Earlier versions of the theory had required tubulin-electrons to form either Bose–Einsteins or Frohlich condensates, and the Reimers group claimed that these were experimentally unfounded. Additionally they claimed that microtubules could only support 'weak' 8 MHz coherence. The first argument was voided by revisions of the theory that described dipole oscillations due to London forces and possibly due to magnetic and/or nuclear spin cloud formations.[6] On the second issue the theory was retrofitted so that 8 MHz coherence is sufficient to support the whole Orch-OR hypothesis.

McKemmish et al. made two claims: that aromatic molecules cannot switch states because they are delocalised; and that changes in tubulin protein-conformation driven by GTP conversion would result in a prohibitive energy requirement. Hameroff and Penrose responded to the first claim by stating that they were referring to the behaviour of two or more electron clouds, inherently non-localised. For the second claim they stated that no GTP conversion is needed since (in that version of the theory) the conformation-switching is not necessary, replaced by oscillation due to the London forces produced by the electron cloud dipole states.

[selimthegrim]

Posner molecules are not the same as phosphate ions.

[bascule]

> Fisher says, if the phosphorus atoms are incorporated into larger objects called "Posner molecules". These are clusters of six phosphate ions, combined with nine calcium ions.

[selimthegrim]

Yes, my point exactly. It’s a complex with calcium.

[bascule]

If that was your point, perhaps you should've mentioned it. That would've made your post informative, rather than merely nitpicking.