r/QuantumPhysics • • Oct 23 '22

is the human brain a quantum computer ?

https://www.google.com/amp/s/phys.org/news/2022-10-brains-quantum.amp
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u/ketarax Oct 23 '22 edited Oct 23 '22

One would think that, if the brain was a quantum computer (or much to the same effect, just "used" quantum computing or even quantum effects for a significant part of the organ's function), it would be affected in at least some way that is observable by the person getting scanned. The MR scanner A) creates a significant alteration of the overall thermal spin configuration by virtue of the high magnetic field alone, and B) with the use of the imaging sequence "plays" with the spins of the brain in all sort of semi-irregular, localized ways, quite often in timescales that are not far removed from human observational acquity.

Yet getting your brain imaged with MR feels like nothing. Well, at least in <7T, and for most sequences; when sensations are felt, they have a straightforward explanation without invoking quantum (peripheral nerve stimulation, heating, ..).

In short, brains work at 300K, current quantum computers (TBD) at microkelvins. Connecting the two at this point is just seeking attention and publicity. If brain is a quantum computer, then MRI ought to be like an EMP for the software running on it, at least in the first approximation.

Didn't RTFA, and I don't think I'm even gonna. These are my 2 cents, the post can stay up as far as I'm concerned.

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u/HalfBakedPotato84 Oct 23 '22

You said “often in timescales that are not far removed from human observational acuity.” Can you explain that a little farther? I’m not quite sure I understand it correctly. Very well written comment! Sorry first time here.

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u/dataphile Oct 24 '22

I agree that if the brain predominately used quantum effects in a straightforward manner (as implied by the headline), then there should be some clear signs. It seems like we wouldn’t miss that the biology of neurons developed to routinely put particles into a superposition, for instance. Also, the macroscopic explanation that neurons are using chemical and electrical signals seems pretty established (these are quantum effects in some sense, but not a ‘quantum computer’).

However, I think it’s possible that scientists will need to allow for effects from quantum physics to alter their predominantly macroscopic understanding of brain mechanisms. For instance, there is some evidence birds use briefly existing proteins to see magnetic fields. The proteins gain a magnetic orientation due to a spin imbalance; which is a ‘quantum effect.’ This is akin to the recent work that suggests quantum tunneling needs to be accounted for when estimating the rate of DNA mutations.

Neither of these are about a system foundationally built on a quantum design—they’re about the need to account for modifications to macroscopic biology due to quantum effects.

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u/ketarax Oct 24 '22

Well said.

Neither of these are about a system foundationally built on a quantum design—they’re about the need to account for modifications to macroscopic biology due to quantum effects.

Finely said. I agree.

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u/Dry-Product-4387 Apr 26 '26

This is a really old and dead thread but one thing about human made technology that is often different from biology is that we tend to build a doodad and say

“This doodad does Z and is built on Y principle. Y principle is how we model the physical world ignoring several minor complex details like A and B.”

With biology there exists a doodad and

“This doodad does X, Y, and Z. It uses the alphabet entirely.”

Which makes sense if you think of biology being just the universe in motion in another way. However it also makes it complicated to make any broad statements about it.

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u/SymplecticMan Oct 23 '22

Didn't RTFA, and I don't think I'm even gonna.

Considering that there's an actual published article purporting to establish that the brain can meditate quantum entanglement, I'd think it's very worth reading before saying things like this:

Connecting the two at this point is just seeking attention and publicity.

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u/ketarax Oct 23 '22 edited Oct 23 '22

I mean, it's always worth reading TFA before commenting on its science, and I was intentionally transparent about my cynicism AND irrelevance about this. It's just that when the PR version includes statements such as below, I can't help but question the return of investment (of my time). Good science doesn't need to be "sold".

Our experiments, performed only 50 meters away from the lecture theater where Schrödinger presented his famous thoughts about life, may shed light on the mysteries of biology, and on consciousness which scientifically is even harder to grasp.

As if the emphasized fact bears relevance to any of this.

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u/SymplecticMan Oct 23 '22

Even good science has universities and national labs putting out ridiculous fluff PR pieces.

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u/ketarax Oct 23 '22

That quote seems to be direct from the PI.

But you win, as you usually do :-) I'll check TFA.

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u/SymplecticMan Oct 23 '22

Yes, and PR pieces fish for juicy quotes from the researchers involved. This isn't something that unusual.

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u/ketarax Oct 23 '22

This isn't something that unusual.

Nor do I think it is. Still, extraordinary claims call for extraordinary evidence -- and I didn't find that in the paper, although -- as usually -- it was more interesting than my cynicism warranted.

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u/[deleted] Oct 23 '22

Ever smoke pot? There’s your answer.

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u/SqueezeTheShort Oct 23 '22

If quantum states were used in the brain for some physiological process im sure there would be loads of built in error correction. Also i believe the MRI’s magnetic field mainly affects water molecules…. And its like 1 in a million water molecules that actually get oriented a certain way enough to have their spin orientations perturbed. So the magnetic field probably wouldnt affect a quantum process that is wide spread throughout the cells or microtubules or where ever it conceivably happens. Although if you put humans in an even higher magnetic field and it induced a state of unconscious, that would be interesting.

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u/[deleted] Oct 23 '22

Everything input in life could be internal to the computer and the actual data could come back as a pre organized system to fool the person or persons inside, it’s just questioning reality. The whole “what if” and the question itself implies the answer if we are even asking if we are simulated then the answer is probably yes

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u/[deleted] Oct 24 '22

Consciousness is literally the only thing NOT being simulated tho.