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A cat, an electron, and a metaphysician walk into a bar

  1. Sep 22, 2012 #1
    Hey all,

    With my first post on the forums I have a pretty simple question (atleast I think). Here goes nothing. What is the relation of superposition and entanglement? In the broadest and simplest explanation possible, how do they correlate? If theres a dead cat in one box, will there be an alive one in another unknown location?

  2. jcsd
  3. Sep 22, 2012 #2
    I have been spending the past two months studying Schrödinger’s Box however, I am approaching it from a completely different angle. I postulate that within the scenario there are several perspectives all existing simultaneously however at different location in time and space. One of the perspectives I call Scientific reality (SR) I define this perspective by explaining that is the point in space and time where all the other perspectives intersect and agree.

    Disclaimer: I have no formal background in physics and no training above a couple very simple college physics classes. I struggle with the math that I need to attempt to prove or disprove my theory so in terms of answering your question I may not be much help. My summations seem at this time to more rooted in philosophy but, I don't believe they belong there. I believe that the evaluation of Schrödinger’s Box has a great deal to do with something I have been referring to as quantumcom. Quantumcom is a geeky word my friends and I have coined to describe the large amount of communication that we believe is taking place between all objects. Maybe I am completely off my rocker; nonetheless I love thinking about this stuff.
  4. Sep 22, 2012 #3
    No. The cat is either dead or alive at any point in time (as well as space) but never both.

    That said.....however per the Many Worlds Interpretation (MWI) there will be an alive cat "elsewhere"

    MWI, and some of the other hypothesis, are wild imaginations/guesses at best. There is no proof for such "interpretations"
    Last edited: Sep 22, 2012
  5. Sep 22, 2012 #4
    what if we could prove the existence of different states of perception and the communication of those perceptions. Then would we be able to prove that the cat doesn't actually exist both alive and dead rather, it is just perceived differently from different places in time and space?
  6. Sep 23, 2012 #5
    yes that's possible. however there are three separate areas mingled in the above paragraph...;)

    1. perceptions can be different...the human brain might perceive things differently....that would be psychology not physics though

    or better still...coming to physics....

    2. (some aspects of) reality can be different....i.e. between different frames of reference....that's relativity....


    quantum mechanics
    3. the focus of Schrodinger cat paradox is on illustrating some aspects of quantum mechanics, not relativity...i.e. the frames of reference are kept the same between all observers....
  7. Sep 23, 2012 #6


    Staff: Mentor

    Exactly whats going on with entanglement, superposition, Schrodinger's Cat and all that is a bit technical. But explaining it as simply as I can here goes. The issue with Schrodinger's Cat is if you work through the math in a 'simplistic' manner it turns out the cat is in some weird sort of superposition of being alive and dead at the same time until you observe it. However if you are more careful and take into account what is called decoherence the quantum system, long before it has a chance to do things like break the vial to kill the cat, that emits the particle interacts with the environment (it becomes entangled with it). Mathematically you do something called tracing over the environment. The outcome is its no longer in a superposition but instead in one state or the other which means once all the shenanigans of breaking a vial etc goes on (or not as the case may be) the cat is definitely alive or dead prior to observation.

  8. Sep 23, 2012 #7
    I agree with you completely however, I believe that perception belongs to physics and we just don't quite understand it enough to define it in terms of measurable data (that is a big statement considering that my degree is in psychology). I also agree with you that there are different frames of reference for reality. I think that there is a scientific reality (something I have been calling SR) which is nothing more than the point in space-time where several other perceptions intersect in terms of the measurement of an event.
  9. Sep 23, 2012 #8
    May I barge in here to state that this isn't necessarily true? Under the Copenhagen Interpretation, it will be in a superposition of both to an outside observer. Whether or not this statement is true depends on your interpretation.
  10. Sep 23, 2012 #9
    This is a really poor thought experiment. It attempts to extrapolate fairly well understood effects of quantum mechanics to an extremely large system that nobody understands. Nobody knows exactly what would happen since nobody has been able to prepare any system even near the complexity of a cat in a superposition. I'm not saying that we shouldn't discuss it, but there isn't really a final correct answer (hence the metaphysicist in the title?).

    My take is that the complexity of the cat will necessarily cause decoherence. Life forms are thermalized objects that cannot be prepared (while alive) in a superposition. It is possible that this is just a technical failure and someday I will be proved wrong, but in the meantime I agree with San K and bhobba.
  11. Sep 23, 2012 #10
    You might find this post useful:

    What's the difference between an entangled state, a superposed state and a cat state?
  12. Sep 25, 2012 #11
    you may barge in however it won't help......;)

    the superposition breaks much before engulfing the cat.....

    once the superposition is broken the "interpretations" go kaput....

    Schrodinger, imho, via the cat paradox, was trying to illustrate the absurdities that arise - if you extend/extrapolate the superposition too far from microscopic objects to macroscopic ones
    Last edited: Sep 25, 2012
  13. Sep 25, 2012 #12
    So if we get a bunch of cats, radioactive materials, and boxes
    Put them in a frame
    and have a robot that checks them when tasked by a monitor
    Would that be a cat ,deadcat, inbetween cat, quantum computer

    *P.S. I'm joking*
  14. Sep 25, 2012 #13
    A metaphysician... a doctor that specializes in treating other doctors?
  15. Sep 25, 2012 #14
    A metaphysician...a person who goes into a dark cellar at night without a light looking for a black cat that isn't there.
  16. Sep 25, 2012 #15
    lets say you have 2 cards, a king and a queen, and you shuffle em up, and you give one to alice and one to bob. neither knows qhich they have.

    so, in a way, alice has a 50% chance of having the queen, and a 50% chance of having the king. the same goes for bob. the cards are in a state of superposition between queen and king (much like the cat being in a superposed state of alive and dead)

    so alice and bob part ways and alice decides to look at her card. because alice can say with 100% certainty the card bob has after she knows her card, the states of the cards are entangled.
  17. Sep 25, 2012 #16
  18. Sep 25, 2012 #17
    that is very Albert Einstein-ish and I believe that the explanation of this entanglement has been proven to work differently than that.

    The card theory is to say that an entangled particle already exists in one state or the other and if particle A is the king then particle B must be the queen and they particles possess those states even if we don't measure them. I believe that quantum mechanics teaches us that this isn't how quantum matter behaves in fact it is the opposite. A quantum particle is neither here nor there and is also here and there at the same time.

    Mind you I have no formal training in this field at all so if I am wrong someone smarter than I am please tell me.
  19. Sep 27, 2012 #18
    No. This is not entanglement. This is just correlation. 100% classical correlation. This type of correlation does NOT violate any Bell inequality.

    Entanglement is a very special type of correlation where the actual measurement of one particle in some way does something to the result of the other particle. This only happens to specially prepared pairs of quantum particles, that really behave as one single quantum system regardless of the distance between them.
  20. Sep 27, 2012 #19


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  21. Sep 27, 2012 #20


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    This is the Bertlmann's socks analogy in a different form. This is not entanglement, as has been mentioned.
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