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BBC Jim Al-Khalili Presentation -- robin bird eyes use quantum entanglement?

  1. Jan 1, 2015 #1

    I searched in this forum and no one has mentioned this. What are the thoughts of general physicists regarding Al-khalili presentation how the robin bird eyes use quantum entanglement? Searching at the net producing the following:


    "They turned to results from recent experiments on European robins, in which the captured birds were exposed to flip-flopping magnetic fields of different strengths during their migration season. The tests revealed that a magnetic field of 15 nanoTesla, less than one-thousandth the strength of Earth's magnetic field, was enough to interfere with a bird's sense of direction (Biophysical Journal, DOI: 10.1016/j.bpj.2008.11.072).
    These oscillating magnetic fields will only disrupt the birds' magnetic compass while the electrons remain entangled. As a weaker magnetic field takes longer to alter an electron's spin, the team calculated that for such tiny fields to have such a strong impact on the birds' compasses the electrons must remain entangled for at least 100 microseconds. Their work will appear in http://prl.aps.org/accepted/L/90079Ya1Ff316529366b47a0c9e2917fa594941b5 [Broken]."

    Elsewhere I found the following how "The results were stunning, as the robins became disoriented and flew aimlessly around the room whenever the field was turned on. At 150 nanoTesla, the field was about 300 times weaker than the Earth's magnetic field, which means the birds should never have become disoriented unless they really were using quantum entanglement to navigate. It does seem to rule out the iron molecule hypothesis, as the field would need to be 100 to 1000 times stronger for iron to be affected."

    As light enters the eye, it hits a protein called the cryptochrome, which surrounds the retina. Electrons in this protein are entangled, but light causes one part of an electron pair to get knocked out. The freed electron starts to wobble in reaction to Earth's magnetic field, but its still entangled brother also experiences these same movements and the magnetic pull from the rest of the molecule. The difference in how these two electrons move - because the free electron is no longer affected by the magnetic pull of the cryptochrome - creates patterns in the retina that the robin's brain can then interpret and use for navigation."

    What is your thoughts on this? More at https://www.sciencenews.org/article/quantum-compass-birds
    Last edited by a moderator: May 7, 2017
  2. jcsd
  3. Jan 1, 2015 #2


    Staff: Mentor

    Is it correct - 100% for sure.

    What are it's implications - does it mean a paradigm shift in the way biology is viewed (ie a lot of biological phenomena, like the weird behaviour of liquid helium, may depend crucially on QM effects - conciousness for example) - that's a lot harder to answer. My gut says - yes - but only time will tell.

    It certainly is a fascinating and interesting interdisciplinary field. IMHO such will be much more commonplace as science progresses and our education system will need to keep up - integrated science programs like they have at Princeton are the way of the future:

    Last edited: Jan 1, 2015
  4. Jan 1, 2015 #3


    User Avatar

    Staff: Mentor

    It is indeed one of those infrequent results that are fascinating, surprising, and plausible (any two of those of three is more common), but it is a brave man who says "100%" of a result before it's been independently repeated.
  5. Jan 1, 2015 #4

    See picture of the so called N@C60 molecule above with nitrogen surrounded by carbon. We know in living system, random walk or heat can thermalize any molecules destroying any fragile quantum coherence.. that is why in laboratory quantum system have to be isolated or decoherence would occur in no time. Does anyone can give any idea how the bird eye can do it or maintain any coherence.? wouldn't the so called cryptochrome protein thermalize too as it forms random walk in the eye? anyone can show how decoherence for certain time are prevented from occurring?
  6. Jan 1, 2015 #5


    Staff: Mentor

    True - I did get carried away a bit - but it just looks 'right'

  7. Jan 1, 2015 #6
    If you were to build circuits to detect 150nanoTesla.. what materials would you use and how would you implement it? don't we have sensors that can do this? Maybe the robin bird eye has amplifier and filters to detect them that may not be related to quantum coherence.
  8. Jan 1, 2015 #7


    Staff: Mentor

    My background is applied math - my knowledge of experimental physics is rudimentary - very rudimentary.

  9. Jan 2, 2015 #8
    I'm looking for computational reference how 2 kHz to 5 MHz that can disrupt the robin compass have to do with spin states... and why do birds sensive to those windows of frequencies when radio waves were just invented the last 2 centuries. The following is details of the physics of spin states and how they can be affected in bird eyes written by a scientist (perhaps you can share what is the math reason for the frequency windows relation to spins, I can't find the computations):


    The following background brief of how the 2 Hz to 5 Mhz window of sensitivity were discovered:


    "Neither power lines nor cellphone signals are to blame for the electromagnetic field effect on the birds, according to the new study published in the 8 May 2014 edition of the http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13290.html. Instead, the culprits consist of frequencies between 2 kHz and 5 MHz, such as AM radio signals and ordinary electronic equipment that might be found in businesses or private homes.

    The discovery came about when researchers at the University of Oldenburg in Germany attempted to set up a typical experiment on the magnetic sense of birds, according to National Geographic's Phenomena blog. But the European robins they used in the studies kept flying in random directions rather than using their magnetic "sixth sense" to find their bearings—until the team came up with the idea of putting a Faraday cage around the birds' windowless huts to block the effects of nearby electromagnetic fields. Suddenly, the birds could navigate using their magnetic compass once more."
    Last edited by a moderator: May 7, 2017
  10. Jan 2, 2015 #9
  11. Jan 2, 2015 #10
    Thanks. I have spent half day searching the net for it and related materials. Helpful one would be

    which reports the origin of the 1.3 MHZ sensitivity as the resonance frequency of the electron

    We now determine an appropriate choice for our parameter
    k in Eqn. 2. In Ref. 10, the authors report that a perturbing
    magnetic field of frequency of 1.316 MHz (i.e. the resonance
    frequency of the ‘remote’ electron) can disrupt the avian compass."

    In summary the reported sensitivity to RF fields implies that
    both amplitude and phase (and thus entanglement) are indeed
    protected within the avian compass. The timescales are at
    least tens of microseconds even for a pure dephasing environment,
    and hundreds of microseconds for the more general
    models. It is not clear why such remarkable protection occurs,
    but given the widely-accepted RP model together with
    the recent experimental data [10], this conclusion follows."

    The mystery is the structure of the Cryptochrome.

    Going back to Al-Khalili. He mentions how about sense of smell may be quantum mechanical.. something not just with molecular shape but with molecular vibration affecting entanglement in our nose sensors...


    This is easier to scrutinize since it involves purely physics concept without complex biophysics of the Cryptochrome. More papers like this would be appreciated.
  12. Jan 2, 2015 #11

    Andy Resnick

    User Avatar
    Science Advisor
    Education Advisor

    I read that paper when it came out, and along with molecular models for photosynthesis (for example, http://www.nature.com/nphys/journal/v6/n6/abs/nphys1652.html) both phenomena use delocalized electrons to 'explain' observed behavior. However, I would caution against extrapolating this model.
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