When I first saw this article by Jim Al-Khalili and Johnjoe McFadden, my skeptical reflex kicked and I was, well, skeptical. Often when quantum mechanics gets mentioned with biology, it’s questionable material. But I’ve seen enough of Al-Khalili’s other work, and as President of the British Humanist Association, I’m not inclined to think he’s subject to being taken in by woo:
You’re powered by quantum mechanics. No, really… | Science | The Observer.
For years biologists have been wary of applying the strange world of quantum mechanics, where particles can be in two places at once or connected over huge distances, to their own field. But it can help to explain some amazing natural phenomena we take for granted.
Al-Khalili and McFadden describe three biological processes where quantum effects are crucial: enzymes, photosynthesis, and animal navigation via Earth’s magnetic field. They finish up with this:
All these quantum effects have come as a big surprise to most scientists who believed that the quantum laws only applied in the microscopic world. All delicate quantum behaviour was thought to be washed away very quickly in bigger objects, such as living cells, containing the turbulent motion of trillions of randomly moving particles. So how does life manage its quantum trickery? Recent research suggests that rather than avoiding molecular storms, life embraces them, rather like the captain of a ship who harnesses turbulent gusts and squalls to maintain his ship upright and on course.
The more I learn about how much quantum physics encroaches on processes in the macroscopic world, the less confident I feel about our knowledge of how the universe works. If quantum effects are so critical to biological processes, that seems to imply that quantum uncertainty plays a much larger role in macroscopic reality than is commonly acknowledged. It seems like a serious strike against determinism, at least determinism within observable reality.
Given our recent discussions, I have to admit that it also makes me a little more nervous about the feasibility of mind uploading. The fact that fundamental and evolutionarily ancient biological processes, like photosynthesis, utilize quantum effects seems to raise the probability that the brain also makes use of those effects. It wouldn’t necessarily mean that we might not someday be able to copy a brain, but it might make the idea of running that copy anywhere but in another biological type substrate infeasible.
Unless of course I’m just overinterpreting this?
17 thoughts on “Biology uses quantum effects.”
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Fascinating points. Very plausible. Need some more empirical data and subject them to some neat out-of-box interpretations, hypotheses and take a look at the handiwork!
Thanks, and I agree that more empirical work is needed. For instance, it’s still just a speculative possibility that the brain uses quantum effects; I haven’t heard of any real evidence for it yet.
SAP: “The more I learn about how much quantum physics encroaches on processes in the macroscopic world, the less confident I feel about our knowledge of how the universe works. If quantum effects are so critical to biological processes, that seems to imply that quantum uncertainty plays a much larger role in macroscopic reality than is commonly acknowledged. It seems like a serious strike against determinism, at least determinism within observable reality.”
I am not as pessimist as you are on this. The entire universe is a macroscopic object, a bit larger than any biologic cell. While the marco-state of the universe (the movement of galaxies) are totally deterministic, its driving force (the dark energy) is powered by Quantum principle (see http://prebabel.blogspot.com/2013/11/why-does-dark-energy-make-universe.html ). No, quantum effects and deterministic are not in conflict but are in mutual immanence (see http://prebabel.blogspot.com/2013/01/welcome-to-camp-of-truth-nobel-laureate.html ).
SAP: “Given our recent discussions, I have to admit that it also makes me a little more nervous about the feasibility of mind uploading.”
See http://scientiasalon.wordpress.com/2014/10/24/identity-a-neurobiological-perspective/comment-page-1/#comment-9075 .
I wouldn’t really call my view pessimistic unless you mean that doubting determinism is pessimistic. And I’m only talking about strict determinism, the idea that everything was determined at the big bang. Obviously what will happen if I drop a ball of sodium into water is pretty deterministic. But it also seems obvious to me that we can’t determine, in our observable universe, whether Schrodinger’s cat is alive.
The more I learn about how much quantum physics encroaches on processes in the macroscopic world, the less confident I feel about our knowledge of how the universe works.
I hear you.
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Speaking of which, some physicists proposed measuring the superposition of a virus. I thought they already did it, but couldn’t find any references. Here’s an older article discussing this idea:
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Interesting article. Thanks for the link!
I don’t see any reason to doubt that quantum effects can have macroscopic results. The very fact that we are discussing quantum mechanics is such an example. But all kinds of technology from lasers to transistors depends on quantum mechanics.
Even regular chemistry depends on quantum mechanics too, so quantum mechanics has to be necessary for biology at some level. I’m not so surprised that nature has devised ways to exploit QM in ingenious ways because evolution will simply do whatever works, no matter how brilliant it seems to us as we try to tease out how it works. If we can figure out how to use QM to produce desirable macroscopic effects there’s no reason to suppose nature couldn’t do the same. It’s had billions of years of trial and error to find these solutions after all.
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Good point. I’d been operating under the assumption that life was a phenomena that started at the molecular level (mostly because that’s as low as most popular science books discuss it). But it appears that was naive.
It reminds me of something I read or heard a while back about what might happen if computer code designed to randomly mutate was allowed to evolve freely. Someone speculated that, among the things it might end up doing, is make use in some way of the magnetic interference fields between hardware components, rather than trying to filter them out.
What concerns me is that the closer life gets to the fundamental layer of reality (at least accessible reality), the harder it seems like it would be to simulate or copy.
I’ve heard of just such an example, where researchers were evolving a circuit that would produce something approximating a sine wave. The circuit which evolved was much better and much more efficient than they dreamed possible. It turns out that it had developed something like an antenna from a line of components, and it was picking up a sine-like radio signal as interference from some nearby equipment.
I don’t think it necessarily makes life more difficult to simulate. Simulating it at the molecular level is already infeasible. There is every reason to believe that the kinds of phenomena life takes advantage of can be simulated at a high level without descending into detailed quantum mechanical simulation, just as chemistry can be simulated at a high level and neural networks can be simulated at a high level.
I think it depends on how crucial the details of those lower level layers are, and how uniform they are. If we have to simulate a brain from the quantum layer up, the amount of processing resources may make it unfeasible, or at least forever keep it from being common.
I’ve been thinking about this since Hariod pointed me to that same The Guardian article. There is a difference, I think, between quantum effects, such as how light works, and the specific quantum phenomenon of waveform collapse (the one truly (seeming) random thing in the universe). There is nothing random in how light refracts, but there is a quantum-level explanation (c.f. Feynman’s Q.E.D for an excellent account of this).
I’d like to know a lot more about those robins. Quantum entanglement is not supposed to allow for transmission of information — such would violate Special Relativity. It would be interesting to know the details of how the robins make use of it.
Excellent points. If I understood the article correctly, the entangled electrons used by the robins takes place completely in their heads, so no long distance communication is involved. But I totally agree it would be interesting to know more.
The problem is that entangled is entangled. It can’t be based on information exchange, because any entangled system that works at short range has to work at any range, potentially violating SR.
It just means the birds must make use of both entangled parts — perhaps comparing them. It might be somewhat similar to how a SQUID works but without superconduction.
Entangled parts have opposing quantities, so perhaps a small magnetic difference is magnified into a differential signal — doubling the apparent value. Two opposing parts spaced far enough apart for a neuron to detect, perhaps?
Totally just guessing, obviously! 😀
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Interesting (and informed) guessing. Thanks!