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Questions on multi-worlds interpretation

  1. Dec 26, 2007 #1
    Can anybody please answer 3 questions realted to MWI:
    i)Suppose I measure anything, then I will also be divided into two different universes according to the no. of probable things. But I don't feel any change. I think everything is going continous. But if it really divides where does 'I' go. I don't feel any change. What thing my mind thinks? Where does that previous 'I' go?
    ii)Suppose there's a match between India and Pakistan going on. There will be many events in the match and hence too many universes will be created. But the result will be either India wins or Pakistan wins. So, different results will happen in different (too many) universes. So, I think all the universes will combine in 2 universes according to the result. Can this happen?
    iii)Suppose an electron is in a superposition of 2 states adn the probability is 0.8 for A and 0.6 for B. Then according to MWI both the things will happen in 2 different universes. Then what's teh matter of probability here if both the things happen?
  2. jcsd
  3. Dec 27, 2007 #2
    I'm not sure that there are easy answers to these questions. As for the first, each "you" continues to exist. To accept many worlds requires you to accept the lack of a definitive "you". They are all you; alternatively there is no "you" beyond your protons neutrons and electrons. Each of your neurons exists many times over therefore making many "you"'s.

    For this reason some dislike the theory as it is tantamount to saying there is no soul.

    On the question of probabilities, remember that even though an event might have a binary outcome, other things are going on simultaneously, thereby
    further splitting the multi universe. The probabilities mean that of all the infinite number of universes in which a particular interaction occurred, in, say, 80% of them one outcome occurs, and in 20%, the other occurs. So dont think of it as two outcomes, two universes. Think of it as every outcome occurs in some subset of an infinite number of universes.
  4. Dec 27, 2007 #3
    i) You go both ways of course, so theres one of you before, and two of you afterwards. Years of time later, the other one, is the one you think about, when you concider what would have happened if the result had been otherwise.
    ii) No even if you only care about the total result and not the each ball thrown, plenty of
    other people watched the whole match, and so did the tv cameras, so universe will not
    combine according to the result, but at a much finer (fine-grained is the technical term) level.
    iii) The amplitides should be 0.8 and 0.6, so that the probablity are 0.64+0.36=1. The probablitity can be thought of as given a width to each particle universe. It doesn't matter that MWI says both happen somewhere. Any observer will see the result with the
    given probablities.
  5. Dec 28, 2007 #4
    Then where the previous 'I' go? Does he go randomly into the one?

    But I have given u only one condition. There are only two points and one electron in the unievrse. Now what will u say?
  6. Dec 28, 2007 #5
    But look I am coming from some event thinking, then the universe is divided and 'I' go in one of the universes. The question is taht I fell nothing. I keep on thinking continously without any break. Now, teh question is that where does I go. Is taht a probability?
    Ok, I provide u with a universe in which only the game is happening. Neglect every other thing. Think that every other thing is calm. Think of ground only. That way would be easier. Then too many universes will be created during the whole play. Now let's examoine the situation right after the match. So, we will find many universes unrelated. But my arguement is that when we take the time interval from start to end we find only 2 probabilities. SO, teh universe should be divided into 2 universes. So, I think when we combine both ideas, teh result is that the universes should be combined according to the result.
    If the width will be changed then the whole concept of parallel unievrses will vanish.
  7. Dec 28, 2007 #6
    "You" wind up in whatever world the observation which "you" witness occurred. If another "you" exists, he witnessed a different result for the measurement.

    If there is one and only one electron in the universe, there can't be two points. :) Also what about your measuring device? The molecular oscillations there cause splits as well. The premise of the question is flawed.

    But nonetheless, yes, if there is truly only one electron in the universe, and it truly is given a binary choice, it will result in precisely two universes.
  8. Dec 28, 2007 #7
    ...um I'm not trying to derail the convo here and if you'd rather me start a new thread than I will but I must ask one question: the "you" and "I" prospective makes no sense to me. After a choice has been made why would one of the out comes be special? I don't have a good working idea of statistics(sp?) however it seems as though you are implying that another entity is being "made up" after thr choice which doesn't make sense to me. Should't it be that the original is modified into two seperate things?
  9. Dec 28, 2007 #8
    Whether the original "Peter" is modified into "PeterA" and "PeterB", or if a new Peter is created entirely, is really an academic question. Even if there's one that's modified into two separate things, by definition they have no awareness of each other, therefore they might as well just be two copies.

    I should add that I really put very little weight into this theory; I personally don't believe it at all and I don't think it makes any testable predictions, to my knowledge, so it's rather academic.
  10. Dec 29, 2007 #9
    So, what's teh matter of probability here if only 2 unievrses will occur?
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