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Arrow of time in copenhagen interpretation.

  1. Jun 24, 2012 #1
    Most physicists don't draw a distinction between past, present and future.. this is called the arrow of time. Physicists such as Sean caroll, Paul Davies e.t.c But if all events exist in some sense then the future is <not> open.

    If the future is not open then determinism is true.. thus copenhagen interpretation must be wrong on that account. yet it's the most popular interpretation and is indeterministic.

    Do the advocates of the copenhagen variation revert back to the idea of an objective time in the universe?? It makes no sense.. if it's indeterminism ontologically.. then that simply must mean that the future is open-- and thus that time really does exist.

    Even if there are uncauses events-- they still have to appear(they were never uncertain to ever occur) since everything is already "finished" in universe without an objective time and thus determinism is correct after all.

    Are these sloppy terminologies with "indeterminism" labels or what's going on here?--
  2. jcsd
  3. Jun 24, 2012 #2


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    Open in which sense? As viewed from "our" point in time? Or when viewed from the future, "after" the event? Or do you plan to define some "outside" view?

    You can work with a 4-dimensional spacetime with all events fixed inside, which perfectly behaves like Copenhagen. Think of a computer simulating a universe (with Copenhagen interpretation) and storing the result.
  4. Jun 24, 2012 #3
    Open in the sense that whatever happens in the future does<not> need to happen.. but of course in a block-universe everything has already happened.. and everything is "stored" like in a fully compromised dvd movie.

    According to the copenhagen interpretation an event clearly doesn't need to happen since it's indeterminism and random... that's my main contention here... nothing is unclear if time does not exist..

    So we really need a genuine time for it to be an ontological uncertainty in the copenhagen version and also abandon causality to prevent any future event from being written in stone so it really is open as to what will happen:).

    "You can work with a 4-dimensional spacetime with all events fixed inside, which perfectly behaves like Copenhagen. Think of a computer simulating a universe (with Copenhagen interpretation) and storing the result."

    But then it can't be indeterminism since every event we observe had to occur if all events already exist even before we encounter them(such as our own future). Nothing is uncertain to happen in a finished movie..the same would be true with a "finished" block-universe.
    Last edited: Jun 24, 2012
  5. Jun 24, 2012 #4
    "Think of a computer simulating a universe (with Copenhagen interpretation) and storing the result."

    During the simulation process it's indeterministic but that would mean a passage of time... Before and after the random selection has been decided and is finished.

    But of course if there was <never> a genuine passage of time as the physicists asserts.. then all events we experience has always existed and thus every future event also already exist and had to be that way.
  6. Jun 24, 2012 #5
    Now you've got ME confused, rocket123456!!! Oh, never mind, I was already confused when I came here. :-)

    I think I agree with your confusion. The uncertainty principle suggests indeterminism, yes? And the quantum formalism requires that no single outcome of a condition may be determined until the collapse of the equation by observation or measurement, yes? Uncertainty means that the potentials of any condition are always greater than one, while the outcome of that condition can never be greater than one. Doesn't this in itself suggest very strongly that time exists, that every condition incorporates a necessary potential for change which is the substance of time?

    I'm sorry. This stuff is all over my head, but I surely agree with you that something is amiss in the stated conclusions of QM here.

  7. Jun 24, 2012 #6
    That's the problem since almost no physicist believe in an objective time(no external clock ticking for the universe which we are experiencing as passage of time)! Hence I wondered if it's an exception with those that adhere to the copenhagen interpretation
  8. Jun 25, 2012 #7


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    I would define indeterminism as "given full knowledge of the universe at time t, it is (in general) impossible to determine the state of the universe at time t'>t". This is satisfied with Copenhagen, even if spacetime is viewed as a 4-dimensional object - which is just a mathematical description.
  9. Jun 25, 2012 #8
    Then it's not correct for Einstein to complain about a lack of determinism... it would only mean in an epistemological sense.. not ontologically...

    If all future events "are out there" and thus had to happen they way they did then it's determinism. Wikipedia labelling the copenhagen interpretation as indeterminism is therefore misstaken.
  10. Jun 25, 2012 #9


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    No, it just uses a different meaning of the word. "are out there" is not well-defined on its own. They "are out there" in the sense that I can assign a time coordinate value to them. So what?
  11. Jun 25, 2012 #10
    "Are out there" means that whatever you will do in an hour is already determined-had to happen... it's not unclear(only to our limited knowledge).

    Now maybe this is why Lawrence Krauss said that all interpretations of quantum mechanics are indeed deterministic, and added that the measurements are indeterministic.

    "Determinism is a philosophy stating that for everything that happens there are conditions such that, given them, nothing else could happen"

    This definition has nothing to do with if you can calculate and aquire knowledge of uppcomming events.

    So if we talk about the actual world we are living in, and place the copenhagen interpretation in a block-universe then it's deterministic by definition!
  12. Jun 25, 2012 #11
    Why does Michio Kaku talk about indeterminism from this theory like it actually means "it did not have to happen"

    He mentions the hypotethical axe murderer and cites Einstein-- and then says he was wrong.

    So that would entail that by indeterminism it is indeed referring to what I was interpreting it to be.
    Last edited by a moderator: Sep 25, 2014
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