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Biology might not be quantum, but its math is quantumlike

123 points · 60 comments · pseudolus

  1. __MatrixMan__ · · focus · HN ↗
    I feel like "is biology quantum?" gates are kept in a needlessly stringent way.

    They say that biological systems are too warm for quantum coherence to persist long enough to have meaningful effects. But if you have some molecule whose conformation is in a superposition of states--however briefly--and then the environment causes it to decohere and take on some fully determined non-quantum shape... that actual shape is still one of many possible ones into which it did not decohere. The environment has still hacked probability to trigger decoherence into this shape and not some other one, and evolution leans on this.

    If you took a classical bag and filled it with classical locks and classical keys and just shook it around for a while, none of those keys would end up in the locks. But because of this quantum lubricant, ligands binding receptors do find themselves in the appropriate conformation to facilitate signal transduction, even at low concentrations. It's absolutely astounding that it works at all, and in a fully classical world it wouldn't for the same reason that the keys don't end up in the locks when you shake the bag for a while.

    Biology is plenty quantum, and the people who are here to tell you it isn't are citing the abundance of interactions as evidence that it is not quantum, but it's through those many interactions that its quantum nature expresses itself.

    Maybe it's not spooky-action-at-a-distance style quantum. Maybe it's not indeterminate enough for this theoretical purpose or that one. If you're trying to cram god in there, well it might not be quite spooky enough for that, but so much of what happens in the macroscopic world would not happen if the quantum world were not as strange as it is, and that's doubly true for biology.

    1. dnautics · · focus · HN ↗
      > If you took a classical bag and filled it with classical locks and classical keys and just shook it around for a while, none of those keys would end up in the locks

      I think you are vastly underestimating the number of collisions required to get an enzyme binding event. We did a back of the envelope calculation in grad school and it was something like >> 10^6 ~ 10^9.

      And you can of course do macroscopic things like this:

      <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=3X6qEE2fHvE" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=3X6qEE2fHvE

      1. ravila4 · · focus · HN ↗
        Exactly, and the classical lock and key analogy ignores electromagnetic and hydrophobic&#x2F;hydrophilic interactions, which we can fully model in classical molecular dynamics systems
        1. dnautics · · focus · HN ↗
          That&#x27;s not correct. Lock and key absolutely does take into account em and hydrophobic interactions. Also, molecular dynamics is nearly useless at modeling these things (which is why heuristic models such as alphafold, Rosetta, dominate)
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