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Can atoms/ ions behave quantum mechanically at biofriendly temperature

  1. Dec 24, 2013 #1
    Can atoms/ ions/ molecules behave quantum mechanically at bio-friendly temperature?

    For example, cells in the human body needs around 37 degree Celsius to function properly. There are however some organisms such as Tardigrade ( which can survive for a few minutes at -273°C and for days at -200°C. Red stomach worm can survive the later temperature for about a year. ) The cells also need exchange of ions, such as Na+, K+ etc for their functioning.

    Do those ions behave quantum mechanically at such temperatures? Or, to put it another way, can any atom, ion or molecules behave quantum mechanically at such temperatures?

    ( Scientists have been able to demonstrate that even large-scale objects can behave quantum mechanically at very low temperature. http://en.wikipedia.org/wiki/Quantum_machine )
     
  2. jcsd
  3. Dec 24, 2013 #2

    bhobba

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    All objects behave quantum mechanically all the time. Quantum effects are common place eg transistors work because the absence of an electron can itself behave like a particle called a hole - this is a purely quantum effect.

    What you may be asking is if some rather strange effects like for example liquid helium which some say is QM writ large can be demonstrated at room temperature? The answer is no. Objects behave in a basically classical way because they are entangled with the environment. The absence of such entanglement can only occur at very low temperatures. And even then many other factors must be removed eg a few stray photons from the CMBR is enough to decohere a dust particle and give it a definite position.

    Thanks
    Bill
     
    Last edited: Dec 24, 2013
  4. Dec 24, 2013 #3
    Thank you very much for answering. Yes, I missed the fact that all matters behave quantum mechanically all the time. And yes, I was asking whether atoms/ ions/ molecules can show those bizarre effects such as being at multiple places at the same time, and that uncertain property of matters that makes them unpredictable. I have almost no knowledge and understanding about quantum mechanics, so please pardon my ignorance.
     
  5. Dec 24, 2013 #4

    bhobba

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    There is no need to seek apology.

    You have shown an interest in a very interesting and exiting area.

    Why not join us and learn about it?

    Check out:
    http://theoreticalminimum.com/

    Post here with any queries - they are most welcome.

    And once you learn a bit you can help others out - its great fun.

    Thanks
    Bill
     
  6. Dec 24, 2013 #5
    Thank you very much, again. I would really love to know more about quantum mechanics, but I have exams starting from next January, and will go on till March, and I haven't prepared myself yet. I hope to reboot learning on it as soon as my exams end. But, thank you very much, again.

    A question about that page, though. I visited it, and saw no links to any forum or discussion page. Where can I post questions?

    And, I will apologise for this. Since I am a little ( or very ) obsessive, I had one more question. But before asking, I want to tell what I understood from this conversation. What I understood is: Atoms/ ions/ molecules can't show those bizarre effects ( such as being at multiple places at the same time, and that uncertain property of matters that makes them unpredictable ) at temperatures NOT VERY LOW, such as -273°C to 200°C ( which is not very low ), because such temperatures ( along with other factors, such as photons ) can get them entangled with the environment.

    Did I get it right? Is -273°C not low enough for atoms/ ions/ molecules to show those counter-intuitive quantum behaviour? If it is low enough, is there a lower limit of temperature that can be considered low enough for atoms/ ions/ molecules to show that kind of behaviour?
     
    Last edited: Dec 24, 2013
  7. Dec 24, 2013 #6

    bhobba

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    Here mate - here.

    Any questions about QM or physics in general you like.

    I would say for this type of counter intuitive behavior, rather than simply technologically startling phenomena like superconductivity, the temperature of liquid helium is about as high as you can go to do it. But its really a matter of opinion just what type of behavior you put in that class.

    You never know, someone may come along tomorrow with something really bizarre at room temperature that relies on quantum weirdness - but as of now I think liquid helium is the upper limit. The reason is this kind of behavior emerges because quantum mechanically objects have a lowest ground state and that is a very very low temperature near absolute zero.

    Thanks
    Bill
     
    Last edited: Dec 24, 2013
  8. Dec 24, 2013 #7
    Oh, sorry, I didn't get that ( by "here", you meant here. )

    And thank you very much for your clarification again. So the larger an object is, the closer to zero kelvin you have to take its temperature to make it show that kind of weird quantum behaviour, right?
     
  9. Dec 24, 2013 #8

    bhobba

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    Sort of - but that is a very loose way of looking at it.

    Thanks
    Bill
     
  10. Dec 24, 2013 #9

    atyy

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    I don't know if these are correct, but some relevant papers are:

    http://arxiv.org/abs/0906.3725
    Sustained Quantum Coherence and Entanglement in the Avian Compass
    Erik Gauger, Elisabeth Rieper, John J. L. Morton, Simon C. Benjamin, Vlatko Vedral

    http://arxiv.org/abs/1104.3883
    A critical view on transport and entanglement in models of photosynthesis
    Markus Tiersch, Sandu Popescu, Hans J. Briegel

    http://arxiv.org/abs/1111.2126
    Persistent dynamic entanglement from classical motion: How bio-molecular machines can generate non-trivial quantum states
    Gian Giacomo Guerreschi, Jianming Cai, Sandu Popescu, Hans J. Briegel
     
  11. Dec 25, 2013 #10
    Thank you very much for answering with links to such remarkable studies. So maybe those birds or plants have some sort of chamber in which quantum decoherence doesn't happen, because certainly larger structures, such as, nuclei of cells don't show quantum coherence.
     
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