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Two atoms at opposite sides of the universe are connected?

  1. Oct 17, 2012 #1
    I am sure you all are familiar with the name Brain Greene. And are probably familiar with his popular videos on quantum physics and quantum mechanics. In one of his videos i believe it was "the fabric of the cosmos" he speaks of how atoms at opposite ends of the universe send and receive messages. If this is possible, our idea of the universe and how things work must be completely backwards, right? Wouldn't this mean the whole entire universe is connected to every single atoms in the entire universe, just like blood cells are to the human body?

    To my point. If this is possible (i assume its theoretical physics) how can this be? Brian Greene began to confuse me a bit when he described how this phenomenon worked, or lack thereof. Anyone with information on how something like this operates please explain.

    Thank you
  2. jcsd
  3. Oct 18, 2012 #2


    Staff: Mentor

    Its got to do with the phenomena of entanglement which basically says when two particles interact then separate they each in some sense know something about the other regardless of how far apart they become (even if they are on opposite sides of the universe) - well roughly anyway - its a bit more subtle than that.

    For more details check out:

  4. Oct 18, 2012 #3


    User Avatar
    Gold Member

    As you will know by now if you have looked into it further, there is no way to use entanglement to send information. It's spooky action at a distance, BUT it doesn't have any practical effect.
  5. Oct 18, 2012 #4

    When atoms are kept in superposition, they are not spatially located in an exact manner as happens at our end of the scales(but superpositions are hard to maintain and entanglement is easily broken).

    Can you find the reference? In most treatments of the CI, measurements are fundamental. I am not sure if it's at all possible to reconcile the traditional worldview(no ftl influences) with something like entanglement.

    If everything is constantly in superposition and the familiar objects are simply excitations of the relative field in qft style.

    Those are mostly philosophical questions(interesting indeed) and at the edge of science(the old paradigm is still correct though FAPP). Don't be surprized if the thread gets locked/deleted.
    Last edited: Oct 18, 2012
  6. Oct 18, 2012 #5

    Certainly, but it's still there and it deserves an explanation(one day)
  7. Oct 18, 2012 #6
    One day indeed I hope I am alive.
  8. Oct 18, 2012 #7
    I wonder what kind of explanation you expect. I think the non-locality of the quantum state space gives a very good explanation.
  9. Oct 18, 2012 #8

    In terms of physics, not mathematics, since i assume this to be a physical universe.
  10. Oct 18, 2012 #9
    So you want a reason for the state space to be what it is? Well, it's the only working construction if you want to create a multi-particle hilbert space.
    Or do you mean a "mechanism" for entanglement? That would be quantum theory.
    Some kind of yet undiscovered interaction that communicates nonlocally?
    I really don't see what kind of explanation you mean with one in terms of "physics"
  11. Oct 18, 2012 #10

    It's irritating when someone starts throwing around terms like "the non-locality of state-space" as if it were somehow a fact. Your view on the matter is an opinion, not fact(most working physicists don't accept non-locality)

    My reasons are basically the same reasons why Einstein started the now famous 35-year EPR debate, if you've forgotten what it was about you may need to go back and re-read the paper. In particular, did Einstein like to think particles had definite positions and momentums at all times and did he worry what that implied for what he believed?
  12. Oct 18, 2012 #11
    The nonlocality of the mathematical construction of the quantum state space is a fact, you cannot deny this. This is why entanglement follows from the construction of the state space. This has nothing to do with my opinion. You may question if the construction is an accurate description of reality, but not that is is what it is.

    That was entirely uncalled for. I have no interest in discussing what Einstein believed or didn't. Quantum theory moved on since he died, and even before. He has some points, and I share much of his criticism, but not all of it. If you want to know what I believe or not read my blog at http://aquantumoftheory.wordpress.com
  13. Oct 18, 2012 #12

    I am not sure that the nonlocality of state space has much to do with any nonlocality in nature(you need nonlocality in nature/the macro scale/, not just in state space, unless you toss out realism as well).

    If anything, it moved in the opposite direction that Einstein was hoping for taking away any hope of an intuitive understanding of the unification of the micro and macro scale. Anyway, thanks for the link, i'll read it to better grasp your points.
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