Could quantum mechanics be necessary to analyze some biology scenarios?Why is a classical formalism necessary...

Why is my solution for the partial pressures of two different gases incorrect?

It took me a lot of time to make this, pls like. (YouTube Comments #1)

Avoiding morning and evening handshakes

Proof by Induction - New to proofs

How can I improve my fireworks photography?

How to satisfy a player character's curiosity about another player character?

How do I add a variable to this curl command?

Should I choose Itemized or Standard deduction?

On what did Lego base the appearance of the new Hogwarts minifigs?

ip vs ifconfig commands pros and cons

Where was Karl Mordo in Infinity War?

F1 visa even for a three-week course?

Is my plan for fixing my water heater leak bad?

Do commercial flights continue with an engine out?

If I delete my router's history can my ISP still provide it to my parents?

How to mitigate "bandwagon attacking" from players?

Why is this code uniquely decodable?

How would an AI self awareness kill switch work?

How to prepare vegetables for a sandwich that can last for several days in a fridge?

Do authors have to be politically correct in article-writing?

Find the number of ways to express 1050 as sum of consecutive integers

How do we edit a novel that's written by several people?

What's a good word to describe a public place that looks like it wouldn't be rough?

Can I become debt free or should I file for bankruptcy? How do I manage my debt and finances?



Could quantum mechanics be necessary to analyze some biology scenarios?


Why is a classical formalism necessary for quantum mechanics?What is the math knowledge necessary for starting Quantum Mechanics?How necessary is the “exponential explosion” in quantum mechanics?A thought experiment with Heisenberg's Uncertainty PrincipleCould quantum mechanics work without the Born rule?I am learning Quantum Mechanics and I have some questions about some basic conceptHeisenberg uncertainty principle clarificationDoes quantum mechanics play a role in the brain?What are some resources for Algebraic quantum mechanics for PhysicistsWhy can't we make shrink/grow rays?













8












$begingroup$


As an example, we could talk about a neuron cell in brain, with a size of $1 mu m$ (=$10^{-6}$ m), being the distance between one neuron and next one in a synaptic connection of around 40 nm (=$40 cdot 10^{-9}$ m) (reference).



According to my information, atomic radius are around 100 pm ($10^{-10}$m), not very far of the synapse size (factor of 400).



Thus, my question is, could quantum mechanics be necessary to analyze biological scenarios, such as neuron cell interaction, etc ?



I've read several examples about why take into account quantum effects, as Heisenberg's uncertainty principle, is "useless" at the scale of usual objects (say a rocket), but what about at the scale of cells ?










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    This question would be even more relevant to the functional structures embedded in the synapse membrane (receptors, re-uptake pumps, voltage-gated $Ca^{++}$ channels, all having sizes around 5 nm).
    $endgroup$
    – Thomas Fritsch
    9 hours ago


















8












$begingroup$


As an example, we could talk about a neuron cell in brain, with a size of $1 mu m$ (=$10^{-6}$ m), being the distance between one neuron and next one in a synaptic connection of around 40 nm (=$40 cdot 10^{-9}$ m) (reference).



According to my information, atomic radius are around 100 pm ($10^{-10}$m), not very far of the synapse size (factor of 400).



Thus, my question is, could quantum mechanics be necessary to analyze biological scenarios, such as neuron cell interaction, etc ?



I've read several examples about why take into account quantum effects, as Heisenberg's uncertainty principle, is "useless" at the scale of usual objects (say a rocket), but what about at the scale of cells ?










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    This question would be even more relevant to the functional structures embedded in the synapse membrane (receptors, re-uptake pumps, voltage-gated $Ca^{++}$ channels, all having sizes around 5 nm).
    $endgroup$
    – Thomas Fritsch
    9 hours ago
















8












8








8


1



$begingroup$


As an example, we could talk about a neuron cell in brain, with a size of $1 mu m$ (=$10^{-6}$ m), being the distance between one neuron and next one in a synaptic connection of around 40 nm (=$40 cdot 10^{-9}$ m) (reference).



According to my information, atomic radius are around 100 pm ($10^{-10}$m), not very far of the synapse size (factor of 400).



Thus, my question is, could quantum mechanics be necessary to analyze biological scenarios, such as neuron cell interaction, etc ?



I've read several examples about why take into account quantum effects, as Heisenberg's uncertainty principle, is "useless" at the scale of usual objects (say a rocket), but what about at the scale of cells ?










share|cite|improve this question











$endgroup$




As an example, we could talk about a neuron cell in brain, with a size of $1 mu m$ (=$10^{-6}$ m), being the distance between one neuron and next one in a synaptic connection of around 40 nm (=$40 cdot 10^{-9}$ m) (reference).



According to my information, atomic radius are around 100 pm ($10^{-10}$m), not very far of the synapse size (factor of 400).



Thus, my question is, could quantum mechanics be necessary to analyze biological scenarios, such as neuron cell interaction, etc ?



I've read several examples about why take into account quantum effects, as Heisenberg's uncertainty principle, is "useless" at the scale of usual objects (say a rocket), but what about at the scale of cells ?







quantum-mechanics biophysics biology






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited 18 mins ago









299792458

2,78652029




2,78652029










asked 10 hours ago









pasaba por aquipasaba por aqui

202112




202112








  • 1




    $begingroup$
    This question would be even more relevant to the functional structures embedded in the synapse membrane (receptors, re-uptake pumps, voltage-gated $Ca^{++}$ channels, all having sizes around 5 nm).
    $endgroup$
    – Thomas Fritsch
    9 hours ago
















  • 1




    $begingroup$
    This question would be even more relevant to the functional structures embedded in the synapse membrane (receptors, re-uptake pumps, voltage-gated $Ca^{++}$ channels, all having sizes around 5 nm).
    $endgroup$
    – Thomas Fritsch
    9 hours ago










1




1




$begingroup$
This question would be even more relevant to the functional structures embedded in the synapse membrane (receptors, re-uptake pumps, voltage-gated $Ca^{++}$ channels, all having sizes around 5 nm).
$endgroup$
– Thomas Fritsch
9 hours ago






$begingroup$
This question would be even more relevant to the functional structures embedded in the synapse membrane (receptors, re-uptake pumps, voltage-gated $Ca^{++}$ channels, all having sizes around 5 nm).
$endgroup$
– Thomas Fritsch
9 hours ago












3 Answers
3






active

oldest

votes


















6












$begingroup$

It should be said that a few years ago (around 2007 I believe) there has been some fuzz in the physics community after some researchers found (some) evidence of quantum behavior in biological systems. Most notably some bacteria. In one of these experiments quantum effects (at ambient temperature!) were observed in the FMO complex and involved say, coherent assisted transport of excitations.
I don't think the results are disputed but I believe the consensus nowadays is that, in a way, those measurements are so precise that after all is not that surprising if a (tiny) effect becomes observables.



There were other biological systems where quantum effects were predicted or observed (avian compass is another one, and even a model for sensing odor) but these were more controversial.



I will add some references if you are interested. Googling FMO complex or quantum-biology should give you plenty of hits.



Added Edit



In fact there is even a Wikipedia page which is quite explanatory



https://en.m.wikipedia.org/wiki/Quantum_biology






share|cite|improve this answer









$endgroup$





















    4












    $begingroup$

    So the short answer is that we don't 100% know but most physicists do not think so.



    The reason that they do not think so comes down to two things: Ehrenfest’s theorem and decoherence.



    Ehrenfest’s theorem is a bound on how weird quantum mechanics can be. It says that on average quantum mechanics is not weird: particular measurement outcomes get correlated in weird ways but the average picture looks always like classical mechanics would say it looks.



    Decoherence says that quantum things start to average out as soon as they get entangled with some broader outside world. So for example a protein folding in water is constantly entangling with those water molecules which constantly entangle with each other, and so the interesting correlations cannot be measured on the protein itself anymore but we would have to involve all of the water molecules too.



    Biological structures that would display quantum features would therefore have to create a safe, non-interacting space for a quantum state to be preserved. This is why the slightly cooky among us like Penrose start from examples like cytoskeleton tubules: they are looking for the tiny little spaces that are walled off from the rest of the world. It is also why smart non-physicists like Searle are very careful to say something like “look I just want to import the bulk features of our quantum realm like nondeterminism but then explain things as classical physics+nondeterminism rather than getting super cooky for quantum mechanics,” it's not that it's wrong to say that it's a quantum system because undoubtedly it is, everything is—it's just that it probably has a very good classical approximation because it couples strongly with all of the noisy things around it.



    Quantum does not really mean “small” and we have created tests of QM spanning kilometers. It just requires “isolated” things, and small nanoscale systems and single atoms happen to be isolated from their surroundings more often than big things like baseballs flying through the many air atoms knocking them all out of the way.






    share|cite|improve this answer











    $endgroup$









    • 2




      $begingroup$
      Physicists may not think so, but chemists are absolutely positive that molecules are unavoidably quantum. Protein folding deals with molecules, so it very likely needs quantum mechanics to explain it fully. See this question on chemistry.SE. Neurons are much larger than proteins, so neurons are probably not quantum.
      $endgroup$
      – Peter Shor
      9 hours ago












    • $begingroup$
      @Peter Shor: neurons are "big" (some of them several meters), but their communication methods (where "memory is stored") are composed / use very smaller parts: synapses, gates, amino-acid carriers, ... .
      $endgroup$
      – pasaba por aqui
      8 hours ago








    • 4




      $begingroup$
      The issue isn't if quantum mechanics plays a role or not—it underlies *everything*—but when and where lumped models and effective theories are more useful and more solvable. Once upon a time it was easy to say that biology was a realm where the less fundamental theories were always better. Improved measurement techniques allow us to see quantum mechanics in action in some biological systems but it may still be more useful or tractable to describe those systems in effective terms. These are the question that you ask when you work in the fuzzy boundaries between fields.
      $endgroup$
      – dmckee
      7 hours ago



















    2












    $begingroup$

    I'll discuss two controversial "quantum mechanics explains it" issues in biophysics.



    A biophysical explanation of olfaction remains incomplete. It mostly centres on two models, neither of which can explain all data, but it's possible olfaction uses a combination of both effects (and possibly also something else). One model, the docking theory, is preferred; it relies on how molecules interact through shape and chemistry. The other, the vibrational, theory, depends on quantum tunnelling.



    Orchestrated objective reduction posits that consciousness relies on quantum effects in neurons. This is at odds with the usual view that connections between neurons are responsible. However, physicists as eminent as Roger Penrose have worked on and championed Orch OR, which is why I'm risking it being mainstream enough for inclusion in an answer here despite our policies. Penrose conjectures that superpositions form spacetime "blisters" that undergo OR in a time $hbar/E_G$, with $E_G$ the blister's gravitational self-energy. A radius-$R$ density-$rho$ neuron has mass $M=frac{4pirho R^3}{3}$, GPE $E_G=frac{3GM^2}{5R}=frac{16pi^2 Grho^2 R^5}{15}$ and OR timescale $frac{15hbar}{16pi^2 Grho^2 R^5}$. For $rho =10^3text{kg},text{m}^{-3},,R=10^{-5}text{m}$ (if you'll pardon such approximations of a neuron) this is $1.5mutext{s}$. Take any such number with a pinch of salt, though, because neurons vary in size.






    share|cite|improve this answer









    $endgroup$













      Your Answer





      StackExchange.ifUsing("editor", function () {
      return StackExchange.using("mathjaxEditing", function () {
      StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
      StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
      });
      });
      }, "mathjax-editing");

      StackExchange.ready(function() {
      var channelOptions = {
      tags: "".split(" "),
      id: "151"
      };
      initTagRenderer("".split(" "), "".split(" "), channelOptions);

      StackExchange.using("externalEditor", function() {
      // Have to fire editor after snippets, if snippets enabled
      if (StackExchange.settings.snippets.snippetsEnabled) {
      StackExchange.using("snippets", function() {
      createEditor();
      });
      }
      else {
      createEditor();
      }
      });

      function createEditor() {
      StackExchange.prepareEditor({
      heartbeatType: 'answer',
      autoActivateHeartbeat: false,
      convertImagesToLinks: false,
      noModals: true,
      showLowRepImageUploadWarning: true,
      reputationToPostImages: null,
      bindNavPrevention: true,
      postfix: "",
      imageUploader: {
      brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
      contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
      allowUrls: true
      },
      noCode: true, onDemand: true,
      discardSelector: ".discard-answer"
      ,immediatelyShowMarkdownHelp:true
      });


      }
      });














      draft saved

      draft discarded


















      StackExchange.ready(
      function () {
      StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fphysics.stackexchange.com%2fquestions%2f464184%2fcould-quantum-mechanics-be-necessary-to-analyze-some-biology-scenarios%23new-answer', 'question_page');
      }
      );

      Post as a guest















      Required, but never shown

























      3 Answers
      3






      active

      oldest

      votes








      3 Answers
      3






      active

      oldest

      votes









      active

      oldest

      votes






      active

      oldest

      votes









      6












      $begingroup$

      It should be said that a few years ago (around 2007 I believe) there has been some fuzz in the physics community after some researchers found (some) evidence of quantum behavior in biological systems. Most notably some bacteria. In one of these experiments quantum effects (at ambient temperature!) were observed in the FMO complex and involved say, coherent assisted transport of excitations.
      I don't think the results are disputed but I believe the consensus nowadays is that, in a way, those measurements are so precise that after all is not that surprising if a (tiny) effect becomes observables.



      There were other biological systems where quantum effects were predicted or observed (avian compass is another one, and even a model for sensing odor) but these were more controversial.



      I will add some references if you are interested. Googling FMO complex or quantum-biology should give you plenty of hits.



      Added Edit



      In fact there is even a Wikipedia page which is quite explanatory



      https://en.m.wikipedia.org/wiki/Quantum_biology






      share|cite|improve this answer









      $endgroup$


















        6












        $begingroup$

        It should be said that a few years ago (around 2007 I believe) there has been some fuzz in the physics community after some researchers found (some) evidence of quantum behavior in biological systems. Most notably some bacteria. In one of these experiments quantum effects (at ambient temperature!) were observed in the FMO complex and involved say, coherent assisted transport of excitations.
        I don't think the results are disputed but I believe the consensus nowadays is that, in a way, those measurements are so precise that after all is not that surprising if a (tiny) effect becomes observables.



        There were other biological systems where quantum effects were predicted or observed (avian compass is another one, and even a model for sensing odor) but these were more controversial.



        I will add some references if you are interested. Googling FMO complex or quantum-biology should give you plenty of hits.



        Added Edit



        In fact there is even a Wikipedia page which is quite explanatory



        https://en.m.wikipedia.org/wiki/Quantum_biology






        share|cite|improve this answer









        $endgroup$
















          6












          6








          6





          $begingroup$

          It should be said that a few years ago (around 2007 I believe) there has been some fuzz in the physics community after some researchers found (some) evidence of quantum behavior in biological systems. Most notably some bacteria. In one of these experiments quantum effects (at ambient temperature!) were observed in the FMO complex and involved say, coherent assisted transport of excitations.
          I don't think the results are disputed but I believe the consensus nowadays is that, in a way, those measurements are so precise that after all is not that surprising if a (tiny) effect becomes observables.



          There were other biological systems where quantum effects were predicted or observed (avian compass is another one, and even a model for sensing odor) but these were more controversial.



          I will add some references if you are interested. Googling FMO complex or quantum-biology should give you plenty of hits.



          Added Edit



          In fact there is even a Wikipedia page which is quite explanatory



          https://en.m.wikipedia.org/wiki/Quantum_biology






          share|cite|improve this answer









          $endgroup$



          It should be said that a few years ago (around 2007 I believe) there has been some fuzz in the physics community after some researchers found (some) evidence of quantum behavior in biological systems. Most notably some bacteria. In one of these experiments quantum effects (at ambient temperature!) were observed in the FMO complex and involved say, coherent assisted transport of excitations.
          I don't think the results are disputed but I believe the consensus nowadays is that, in a way, those measurements are so precise that after all is not that surprising if a (tiny) effect becomes observables.



          There were other biological systems where quantum effects were predicted or observed (avian compass is another one, and even a model for sensing odor) but these were more controversial.



          I will add some references if you are interested. Googling FMO complex or quantum-biology should give you plenty of hits.



          Added Edit



          In fact there is even a Wikipedia page which is quite explanatory



          https://en.m.wikipedia.org/wiki/Quantum_biology







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered 9 hours ago









          lcvlcv

          50325




          50325























              4












              $begingroup$

              So the short answer is that we don't 100% know but most physicists do not think so.



              The reason that they do not think so comes down to two things: Ehrenfest’s theorem and decoherence.



              Ehrenfest’s theorem is a bound on how weird quantum mechanics can be. It says that on average quantum mechanics is not weird: particular measurement outcomes get correlated in weird ways but the average picture looks always like classical mechanics would say it looks.



              Decoherence says that quantum things start to average out as soon as they get entangled with some broader outside world. So for example a protein folding in water is constantly entangling with those water molecules which constantly entangle with each other, and so the interesting correlations cannot be measured on the protein itself anymore but we would have to involve all of the water molecules too.



              Biological structures that would display quantum features would therefore have to create a safe, non-interacting space for a quantum state to be preserved. This is why the slightly cooky among us like Penrose start from examples like cytoskeleton tubules: they are looking for the tiny little spaces that are walled off from the rest of the world. It is also why smart non-physicists like Searle are very careful to say something like “look I just want to import the bulk features of our quantum realm like nondeterminism but then explain things as classical physics+nondeterminism rather than getting super cooky for quantum mechanics,” it's not that it's wrong to say that it's a quantum system because undoubtedly it is, everything is—it's just that it probably has a very good classical approximation because it couples strongly with all of the noisy things around it.



              Quantum does not really mean “small” and we have created tests of QM spanning kilometers. It just requires “isolated” things, and small nanoscale systems and single atoms happen to be isolated from their surroundings more often than big things like baseballs flying through the many air atoms knocking them all out of the way.






              share|cite|improve this answer











              $endgroup$









              • 2




                $begingroup$
                Physicists may not think so, but chemists are absolutely positive that molecules are unavoidably quantum. Protein folding deals with molecules, so it very likely needs quantum mechanics to explain it fully. See this question on chemistry.SE. Neurons are much larger than proteins, so neurons are probably not quantum.
                $endgroup$
                – Peter Shor
                9 hours ago












              • $begingroup$
                @Peter Shor: neurons are "big" (some of them several meters), but their communication methods (where "memory is stored") are composed / use very smaller parts: synapses, gates, amino-acid carriers, ... .
                $endgroup$
                – pasaba por aqui
                8 hours ago








              • 4




                $begingroup$
                The issue isn't if quantum mechanics plays a role or not—it underlies *everything*—but when and where lumped models and effective theories are more useful and more solvable. Once upon a time it was easy to say that biology was a realm where the less fundamental theories were always better. Improved measurement techniques allow us to see quantum mechanics in action in some biological systems but it may still be more useful or tractable to describe those systems in effective terms. These are the question that you ask when you work in the fuzzy boundaries between fields.
                $endgroup$
                – dmckee
                7 hours ago
















              4












              $begingroup$

              So the short answer is that we don't 100% know but most physicists do not think so.



              The reason that they do not think so comes down to two things: Ehrenfest’s theorem and decoherence.



              Ehrenfest’s theorem is a bound on how weird quantum mechanics can be. It says that on average quantum mechanics is not weird: particular measurement outcomes get correlated in weird ways but the average picture looks always like classical mechanics would say it looks.



              Decoherence says that quantum things start to average out as soon as they get entangled with some broader outside world. So for example a protein folding in water is constantly entangling with those water molecules which constantly entangle with each other, and so the interesting correlations cannot be measured on the protein itself anymore but we would have to involve all of the water molecules too.



              Biological structures that would display quantum features would therefore have to create a safe, non-interacting space for a quantum state to be preserved. This is why the slightly cooky among us like Penrose start from examples like cytoskeleton tubules: they are looking for the tiny little spaces that are walled off from the rest of the world. It is also why smart non-physicists like Searle are very careful to say something like “look I just want to import the bulk features of our quantum realm like nondeterminism but then explain things as classical physics+nondeterminism rather than getting super cooky for quantum mechanics,” it's not that it's wrong to say that it's a quantum system because undoubtedly it is, everything is—it's just that it probably has a very good classical approximation because it couples strongly with all of the noisy things around it.



              Quantum does not really mean “small” and we have created tests of QM spanning kilometers. It just requires “isolated” things, and small nanoscale systems and single atoms happen to be isolated from their surroundings more often than big things like baseballs flying through the many air atoms knocking them all out of the way.






              share|cite|improve this answer











              $endgroup$









              • 2




                $begingroup$
                Physicists may not think so, but chemists are absolutely positive that molecules are unavoidably quantum. Protein folding deals with molecules, so it very likely needs quantum mechanics to explain it fully. See this question on chemistry.SE. Neurons are much larger than proteins, so neurons are probably not quantum.
                $endgroup$
                – Peter Shor
                9 hours ago












              • $begingroup$
                @Peter Shor: neurons are "big" (some of them several meters), but their communication methods (where "memory is stored") are composed / use very smaller parts: synapses, gates, amino-acid carriers, ... .
                $endgroup$
                – pasaba por aqui
                8 hours ago








              • 4




                $begingroup$
                The issue isn't if quantum mechanics plays a role or not—it underlies *everything*—but when and where lumped models and effective theories are more useful and more solvable. Once upon a time it was easy to say that biology was a realm where the less fundamental theories were always better. Improved measurement techniques allow us to see quantum mechanics in action in some biological systems but it may still be more useful or tractable to describe those systems in effective terms. These are the question that you ask when you work in the fuzzy boundaries between fields.
                $endgroup$
                – dmckee
                7 hours ago














              4












              4








              4





              $begingroup$

              So the short answer is that we don't 100% know but most physicists do not think so.



              The reason that they do not think so comes down to two things: Ehrenfest’s theorem and decoherence.



              Ehrenfest’s theorem is a bound on how weird quantum mechanics can be. It says that on average quantum mechanics is not weird: particular measurement outcomes get correlated in weird ways but the average picture looks always like classical mechanics would say it looks.



              Decoherence says that quantum things start to average out as soon as they get entangled with some broader outside world. So for example a protein folding in water is constantly entangling with those water molecules which constantly entangle with each other, and so the interesting correlations cannot be measured on the protein itself anymore but we would have to involve all of the water molecules too.



              Biological structures that would display quantum features would therefore have to create a safe, non-interacting space for a quantum state to be preserved. This is why the slightly cooky among us like Penrose start from examples like cytoskeleton tubules: they are looking for the tiny little spaces that are walled off from the rest of the world. It is also why smart non-physicists like Searle are very careful to say something like “look I just want to import the bulk features of our quantum realm like nondeterminism but then explain things as classical physics+nondeterminism rather than getting super cooky for quantum mechanics,” it's not that it's wrong to say that it's a quantum system because undoubtedly it is, everything is—it's just that it probably has a very good classical approximation because it couples strongly with all of the noisy things around it.



              Quantum does not really mean “small” and we have created tests of QM spanning kilometers. It just requires “isolated” things, and small nanoscale systems and single atoms happen to be isolated from their surroundings more often than big things like baseballs flying through the many air atoms knocking them all out of the way.






              share|cite|improve this answer











              $endgroup$



              So the short answer is that we don't 100% know but most physicists do not think so.



              The reason that they do not think so comes down to two things: Ehrenfest’s theorem and decoherence.



              Ehrenfest’s theorem is a bound on how weird quantum mechanics can be. It says that on average quantum mechanics is not weird: particular measurement outcomes get correlated in weird ways but the average picture looks always like classical mechanics would say it looks.



              Decoherence says that quantum things start to average out as soon as they get entangled with some broader outside world. So for example a protein folding in water is constantly entangling with those water molecules which constantly entangle with each other, and so the interesting correlations cannot be measured on the protein itself anymore but we would have to involve all of the water molecules too.



              Biological structures that would display quantum features would therefore have to create a safe, non-interacting space for a quantum state to be preserved. This is why the slightly cooky among us like Penrose start from examples like cytoskeleton tubules: they are looking for the tiny little spaces that are walled off from the rest of the world. It is also why smart non-physicists like Searle are very careful to say something like “look I just want to import the bulk features of our quantum realm like nondeterminism but then explain things as classical physics+nondeterminism rather than getting super cooky for quantum mechanics,” it's not that it's wrong to say that it's a quantum system because undoubtedly it is, everything is—it's just that it probably has a very good classical approximation because it couples strongly with all of the noisy things around it.



              Quantum does not really mean “small” and we have created tests of QM spanning kilometers. It just requires “isolated” things, and small nanoscale systems and single atoms happen to be isolated from their surroundings more often than big things like baseballs flying through the many air atoms knocking them all out of the way.







              share|cite|improve this answer














              share|cite|improve this answer



              share|cite|improve this answer








              edited 10 hours ago

























              answered 10 hours ago









              CR DrostCR Drost

              21.8k11959




              21.8k11959








              • 2




                $begingroup$
                Physicists may not think so, but chemists are absolutely positive that molecules are unavoidably quantum. Protein folding deals with molecules, so it very likely needs quantum mechanics to explain it fully. See this question on chemistry.SE. Neurons are much larger than proteins, so neurons are probably not quantum.
                $endgroup$
                – Peter Shor
                9 hours ago












              • $begingroup$
                @Peter Shor: neurons are "big" (some of them several meters), but their communication methods (where "memory is stored") are composed / use very smaller parts: synapses, gates, amino-acid carriers, ... .
                $endgroup$
                – pasaba por aqui
                8 hours ago








              • 4




                $begingroup$
                The issue isn't if quantum mechanics plays a role or not—it underlies *everything*—but when and where lumped models and effective theories are more useful and more solvable. Once upon a time it was easy to say that biology was a realm where the less fundamental theories were always better. Improved measurement techniques allow us to see quantum mechanics in action in some biological systems but it may still be more useful or tractable to describe those systems in effective terms. These are the question that you ask when you work in the fuzzy boundaries between fields.
                $endgroup$
                – dmckee
                7 hours ago














              • 2




                $begingroup$
                Physicists may not think so, but chemists are absolutely positive that molecules are unavoidably quantum. Protein folding deals with molecules, so it very likely needs quantum mechanics to explain it fully. See this question on chemistry.SE. Neurons are much larger than proteins, so neurons are probably not quantum.
                $endgroup$
                – Peter Shor
                9 hours ago












              • $begingroup$
                @Peter Shor: neurons are "big" (some of them several meters), but their communication methods (where "memory is stored") are composed / use very smaller parts: synapses, gates, amino-acid carriers, ... .
                $endgroup$
                – pasaba por aqui
                8 hours ago








              • 4




                $begingroup$
                The issue isn't if quantum mechanics plays a role or not—it underlies *everything*—but when and where lumped models and effective theories are more useful and more solvable. Once upon a time it was easy to say that biology was a realm where the less fundamental theories were always better. Improved measurement techniques allow us to see quantum mechanics in action in some biological systems but it may still be more useful or tractable to describe those systems in effective terms. These are the question that you ask when you work in the fuzzy boundaries between fields.
                $endgroup$
                – dmckee
                7 hours ago








              2




              2




              $begingroup$
              Physicists may not think so, but chemists are absolutely positive that molecules are unavoidably quantum. Protein folding deals with molecules, so it very likely needs quantum mechanics to explain it fully. See this question on chemistry.SE. Neurons are much larger than proteins, so neurons are probably not quantum.
              $endgroup$
              – Peter Shor
              9 hours ago






              $begingroup$
              Physicists may not think so, but chemists are absolutely positive that molecules are unavoidably quantum. Protein folding deals with molecules, so it very likely needs quantum mechanics to explain it fully. See this question on chemistry.SE. Neurons are much larger than proteins, so neurons are probably not quantum.
              $endgroup$
              – Peter Shor
              9 hours ago














              $begingroup$
              @Peter Shor: neurons are "big" (some of them several meters), but their communication methods (where "memory is stored") are composed / use very smaller parts: synapses, gates, amino-acid carriers, ... .
              $endgroup$
              – pasaba por aqui
              8 hours ago






              $begingroup$
              @Peter Shor: neurons are "big" (some of them several meters), but their communication methods (where "memory is stored") are composed / use very smaller parts: synapses, gates, amino-acid carriers, ... .
              $endgroup$
              – pasaba por aqui
              8 hours ago






              4




              4




              $begingroup$
              The issue isn't if quantum mechanics plays a role or not—it underlies *everything*—but when and where lumped models and effective theories are more useful and more solvable. Once upon a time it was easy to say that biology was a realm where the less fundamental theories were always better. Improved measurement techniques allow us to see quantum mechanics in action in some biological systems but it may still be more useful or tractable to describe those systems in effective terms. These are the question that you ask when you work in the fuzzy boundaries between fields.
              $endgroup$
              – dmckee
              7 hours ago




              $begingroup$
              The issue isn't if quantum mechanics plays a role or not—it underlies *everything*—but when and where lumped models and effective theories are more useful and more solvable. Once upon a time it was easy to say that biology was a realm where the less fundamental theories were always better. Improved measurement techniques allow us to see quantum mechanics in action in some biological systems but it may still be more useful or tractable to describe those systems in effective terms. These are the question that you ask when you work in the fuzzy boundaries between fields.
              $endgroup$
              – dmckee
              7 hours ago











              2












              $begingroup$

              I'll discuss two controversial "quantum mechanics explains it" issues in biophysics.



              A biophysical explanation of olfaction remains incomplete. It mostly centres on two models, neither of which can explain all data, but it's possible olfaction uses a combination of both effects (and possibly also something else). One model, the docking theory, is preferred; it relies on how molecules interact through shape and chemistry. The other, the vibrational, theory, depends on quantum tunnelling.



              Orchestrated objective reduction posits that consciousness relies on quantum effects in neurons. This is at odds with the usual view that connections between neurons are responsible. However, physicists as eminent as Roger Penrose have worked on and championed Orch OR, which is why I'm risking it being mainstream enough for inclusion in an answer here despite our policies. Penrose conjectures that superpositions form spacetime "blisters" that undergo OR in a time $hbar/E_G$, with $E_G$ the blister's gravitational self-energy. A radius-$R$ density-$rho$ neuron has mass $M=frac{4pirho R^3}{3}$, GPE $E_G=frac{3GM^2}{5R}=frac{16pi^2 Grho^2 R^5}{15}$ and OR timescale $frac{15hbar}{16pi^2 Grho^2 R^5}$. For $rho =10^3text{kg},text{m}^{-3},,R=10^{-5}text{m}$ (if you'll pardon such approximations of a neuron) this is $1.5mutext{s}$. Take any such number with a pinch of salt, though, because neurons vary in size.






              share|cite|improve this answer









              $endgroup$


















                2












                $begingroup$

                I'll discuss two controversial "quantum mechanics explains it" issues in biophysics.



                A biophysical explanation of olfaction remains incomplete. It mostly centres on two models, neither of which can explain all data, but it's possible olfaction uses a combination of both effects (and possibly also something else). One model, the docking theory, is preferred; it relies on how molecules interact through shape and chemistry. The other, the vibrational, theory, depends on quantum tunnelling.



                Orchestrated objective reduction posits that consciousness relies on quantum effects in neurons. This is at odds with the usual view that connections between neurons are responsible. However, physicists as eminent as Roger Penrose have worked on and championed Orch OR, which is why I'm risking it being mainstream enough for inclusion in an answer here despite our policies. Penrose conjectures that superpositions form spacetime "blisters" that undergo OR in a time $hbar/E_G$, with $E_G$ the blister's gravitational self-energy. A radius-$R$ density-$rho$ neuron has mass $M=frac{4pirho R^3}{3}$, GPE $E_G=frac{3GM^2}{5R}=frac{16pi^2 Grho^2 R^5}{15}$ and OR timescale $frac{15hbar}{16pi^2 Grho^2 R^5}$. For $rho =10^3text{kg},text{m}^{-3},,R=10^{-5}text{m}$ (if you'll pardon such approximations of a neuron) this is $1.5mutext{s}$. Take any such number with a pinch of salt, though, because neurons vary in size.






                share|cite|improve this answer









                $endgroup$
















                  2












                  2








                  2





                  $begingroup$

                  I'll discuss two controversial "quantum mechanics explains it" issues in biophysics.



                  A biophysical explanation of olfaction remains incomplete. It mostly centres on two models, neither of which can explain all data, but it's possible olfaction uses a combination of both effects (and possibly also something else). One model, the docking theory, is preferred; it relies on how molecules interact through shape and chemistry. The other, the vibrational, theory, depends on quantum tunnelling.



                  Orchestrated objective reduction posits that consciousness relies on quantum effects in neurons. This is at odds with the usual view that connections between neurons are responsible. However, physicists as eminent as Roger Penrose have worked on and championed Orch OR, which is why I'm risking it being mainstream enough for inclusion in an answer here despite our policies. Penrose conjectures that superpositions form spacetime "blisters" that undergo OR in a time $hbar/E_G$, with $E_G$ the blister's gravitational self-energy. A radius-$R$ density-$rho$ neuron has mass $M=frac{4pirho R^3}{3}$, GPE $E_G=frac{3GM^2}{5R}=frac{16pi^2 Grho^2 R^5}{15}$ and OR timescale $frac{15hbar}{16pi^2 Grho^2 R^5}$. For $rho =10^3text{kg},text{m}^{-3},,R=10^{-5}text{m}$ (if you'll pardon such approximations of a neuron) this is $1.5mutext{s}$. Take any such number with a pinch of salt, though, because neurons vary in size.






                  share|cite|improve this answer









                  $endgroup$



                  I'll discuss two controversial "quantum mechanics explains it" issues in biophysics.



                  A biophysical explanation of olfaction remains incomplete. It mostly centres on two models, neither of which can explain all data, but it's possible olfaction uses a combination of both effects (and possibly also something else). One model, the docking theory, is preferred; it relies on how molecules interact through shape and chemistry. The other, the vibrational, theory, depends on quantum tunnelling.



                  Orchestrated objective reduction posits that consciousness relies on quantum effects in neurons. This is at odds with the usual view that connections between neurons are responsible. However, physicists as eminent as Roger Penrose have worked on and championed Orch OR, which is why I'm risking it being mainstream enough for inclusion in an answer here despite our policies. Penrose conjectures that superpositions form spacetime "blisters" that undergo OR in a time $hbar/E_G$, with $E_G$ the blister's gravitational self-energy. A radius-$R$ density-$rho$ neuron has mass $M=frac{4pirho R^3}{3}$, GPE $E_G=frac{3GM^2}{5R}=frac{16pi^2 Grho^2 R^5}{15}$ and OR timescale $frac{15hbar}{16pi^2 Grho^2 R^5}$. For $rho =10^3text{kg},text{m}^{-3},,R=10^{-5}text{m}$ (if you'll pardon such approximations of a neuron) this is $1.5mutext{s}$. Take any such number with a pinch of salt, though, because neurons vary in size.







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  answered 9 hours ago









                  J.G.J.G.

                  9,24921528




                  9,24921528






























                      draft saved

                      draft discarded




















































                      Thanks for contributing an answer to Physics Stack Exchange!


                      • Please be sure to answer the question. Provide details and share your research!

                      But avoid



                      • Asking for help, clarification, or responding to other answers.

                      • Making statements based on opinion; back them up with references or personal experience.


                      Use MathJax to format equations. MathJax reference.


                      To learn more, see our tips on writing great answers.




                      draft saved


                      draft discarded














                      StackExchange.ready(
                      function () {
                      StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fphysics.stackexchange.com%2fquestions%2f464184%2fcould-quantum-mechanics-be-necessary-to-analyze-some-biology-scenarios%23new-answer', 'question_page');
                      }
                      );

                      Post as a guest















                      Required, but never shown





















































                      Required, but never shown














                      Required, but never shown












                      Required, but never shown







                      Required, but never shown

































                      Required, but never shown














                      Required, but never shown












                      Required, but never shown







                      Required, but never shown







                      Popular posts from this blog

                      “%fieldName is a required field.”, in Magento2 REST API Call for GET Method Type The Next...

                      How to change City field to a dropdown in Checkout step Magento 2Magento 2 : How to change UI field(s)...

                      變成蝙蝠會怎樣? 參考資料 外部連結 导航菜单Thomas Nagel, "What is it like to be a...