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Beyond determinism?

  1. Jul 15, 2008 #1
    With the assumption that the Big Bang model is correct, is it conceivable that perhaps the initial state of the universe would in fact determine every single event that ever happened thereafter?

    In other words, given the same initial starting condition, could it have possibly resulted in anything different than that of what we know of today, if allowed to play out a second time? This seems very unlikely.

    Are not these very words, written by myself, nothing more than a consequence of the initial conditions?
  2. jcsd
  3. Jul 15, 2008 #2
    According to quantum mechanics it is impossible to precisely determine the exact whereabouts of particles. So you can't really know what's going on behind the scenes.

    Also in QM a superposition principle says that a system exists in many different possible states at any time. But you won't know in which state a system is unless you make a measurement. When you take a measurement, then all those possible states collapse into one state. Fine, but if you take another measurement subsequently, then you might measure something else altogether,that is another state out of a pool of possibilities so to speak.

    That's why Einstein said "god does not play dice with the universe."
  4. Jul 16, 2008 #3
    I dont think we yet really know the answer to that question. In the classical/newtonian era before qm theory was developed; most phycists would probaby hedge for a Deterministic universe. Now with qm it's a very contentious issue.

    Leaving aside the qm argument, personally my feeling is this universe is at least partly non deterministic. Think about it; what would be the implications for future human progress if we were able to absolutely predict the life from start to finnish? Who you married, hw many kids you would have, who then they would marry and so on....

    To me it makes no sense because if we could acurately predict all these things it means we could also predict our own death. So even if we do exist in a deterministic universe i would think that nature would hide the truth as it seems to me to be an antithesis of evolution and biological progress.
  5. Jul 16, 2008 #4
    At out level of existence, everything is determined.
  6. Jul 16, 2008 #5
    In Everret's interpretation, all the possibilities are realized. Nitpicking, sure, especially since already at the classical level one would need to know the initial with infinite precision, which makes the whole procedure useless.
  7. Jul 16, 2008 #6
    I must admit that i find MWI very counter-intuitive and confusing. For instance if one reads the wiki explanation it is highly contradictory. On the one hand MWI purports to not require an observer or even a measurment to take place in order for the branching to occur; but reading the wiki version it mentions "observers" and "measurement". For instance wiki:

    "MWI response: the decoherence or "splitting" or "branching" is complete when the measurement is complete. In Dirac notation a measurement is complete when:
    where O represents the observer having detected the object system in the i-th state. Before the measurement has started the observer states are identical; after the measurement is complete the observer states are orthonormal.[5][1] Thus a measurement defines the branching process: the branching is as well- or ill- defined as the measurement is. Thus branching is complete when the measurement is complete. Since the role of the observer and measurement per se plays no special role in MWI (measurements are handled as all other interactions are) there is no need for a precise definition of what an observer or a measurement is -- just as in Newtonian physics no precise definition of either an observer or a measurement was required or expected. In all circumstances the universal wavefunction is still available to give a complete description of reality."

    Just see how many times those two words are used in that explanation .

    However when pushed on why this interpretation keeps using that terminoloy to supposedly describe an observer-less, or measurement-less model - no rational explanation is forthcoming. Instead we are told that in the case of MWI, a measurement is treated as something else. That really is semantic nionsense. Either a measurement is what we all understand it to be or MWI needs to use different terminology.

    Other problems i have with MWI include its clear contradiction of nature's conservation of energy. Its no good saying that because there are different universes the principle of energy conservation is still maintained in each single universe. The problem with that argument is that the branch universes are still part of the qm system, so it doesnt matter how many universes one has to play with they are actually part of the same physics platform. Where as CI with no tweaking abides by conservation of energy. CI is far more efficient with its use of matter/energy than MWI which wastes it on a scale which makes human decadence appear stingy

    Another problem is this idea of a multitude of universes to explain the biophillic tuning of the universe we find ouselves in. I consider any theory which requires an infinite amount of universes as highly dubious apart from the fact it contravenes Occam's priniciple.

    So what has MWI got going for it compared to much more simple and straight-forward qm intepretations? Personally the only saving grace i can see is that it attempts (though unsuccessfully) to rid qm of the essentiality of an observer, or conscious measurement. I dont think its enough since it doesnt even do that satisfactorily.
    Last edited: Jul 16, 2008
  8. Jul 17, 2008 #7
    The universe doesn't appear to play with us, or hide its workings from us.
    Just because we are aware of ourselves doesn't mean the universe means for us to not predict everything.
    In fact, we've been able to predict almost everything so far, otherwise we wouldn't be able to function in this world.

    Which takes me to my next point. There's very little, or most likely zero non determinism in the macroscopic world.
    I don't think anyone has encountered a car that suddenly flew or whatever yet.
    Why should there be non determinism in the micro/subatomic world?
    If energy cannot be created or destroyed, and the universe is deterministic, then everything since the dawn of space and time could be predicted since then.

    Another thing is that if there was non determinism on small scales, why didn't it propagate through the system?
  9. Jul 17, 2008 #8
    Hi octelcogopod,

    "The universe doesn't appear to play with us, or hide its workings from us"

    I think it does "appear" to play with us but that could just be because we don't fully understand how the universe and nature functions.

    "In fact, we've been able to predict almost everything so far, otherwise we wouldn't be able to function in this world"

    I'm not sure about almost everything. Yes some things, but there are many things we cannot accurately predict and not for want of trying such as the weather, or earthquakes etc..Just because we can predict some things does not necessarily mean we can predict everything. I would just refer to chaos theory for some good examples of classically deterministic systems which demonstrate chaotic results given enough time, or interactons.

    And of course on the microscopic scale qm is for the moment (until local variables are shown to exist) non-deterministic, or atleast uncertain. Also that's not taking into account the observer's choices of measurment on a qm system. Obviously thats whole other discussion about free-will :smile:

    "Which takes me to my next point. There's very little, or most likely zero non determinism in the macroscopic world"

    I'd say its mixed and biology may be a non-deterministic aspect of the universe. Our whole lives is a struggle against the clock, the environment etc...it seems to me evolution itself is almost like a struggle against determinism. So i suspect we could have a ying yang thing happening with determinism/non-determinsm, in the same way that the physical constants are so tightly balanced.

    "I don't think anyone has encountered a car that suddenly flew or whatever yet."

    Well if you calculate the uncertainty principle for a particle and then extrapolate that into an object the size of a car the chances of it flying would probably be close to absolute nil - a virtual impossibility. I think this is why we dont see the car flying. Perhaps someone who understands the HUP better than i can confirm how it is applied to macroscopic objects.

    "Why should there be non determinism in the micro/subatomic world?"

    I don't know but it appears to be that way.

    "If energy cannot be created or destroyed, and the universe is deterministic, then everything since the dawn of space and time could be predicted since then."

    Again that's not taking into account quantum fluctuations, or the the uncertainty in qm, or the potential for biological free-will/choice (if its genuine).

    "Another thing is that if there was non determinism on small scales, why didn't it propagate through the system?"

    We dont know it doesnt. And as i mentioned with chaos theory macroscopic scales also exhibit non-determinstic tendencies. If we really live in a Deterministic universe then we are missing some quite big parts of the physics jigsaw.

    However you are in good company with people like Einstein :smile:
  10. Jul 17, 2008 #9
    On large scales you have probabilities that can accurately predict what's going to happen (like radioactive decay), however on a quantum scale you cannot predict with any accuracy what's going on in that region of space.

    At the time of the Big Bang, the universe was smaller than Planck's length which makes events during that time period completely unpredictable. If you rewound time and let it all begin again I seriously doubt things would be exactly the same. In fact, the entire structure of the universe was probably determined at this point and possibly the physical laws themselves.
  11. Jul 17, 2008 #10
    The thing here is.....we don't know what are the initial conditions of everything. We don't even know how the initial conditions got there/here in the first or whatever place.
  12. Jul 17, 2008 #11
  13. Jul 17, 2008 #12
    This is a contradiction. If it "got there" then it wasn't always there. What has always been there never "got there". Ever. Claiming that the universe has always existed simply means that it didn't magically appear out of nothing, no further explanation is needed to understand this.
  14. Jul 18, 2008 #13
    Regardless of what assumptions you're making from your own assumptions. The question is....'how did it get there?', aka how did energy become abundant? You don't know. Here, I'm just choosing a point to start from ..... say ...energy. There's no telling how far things go behind/before/around energy. Like, what mechanisms made energy abundant? And what's behind those mechanisms? And behind those?

    Do you think about this kind of thing?

    Anyway, the biggest puzzle of the universe is: how did anything become abundant? And to say it was always here doesn't cut it, because of the 'how did it get there' question.
  15. Jul 18, 2008 #14
    You are describing the tower of turtles problem with most cosmological theories. It seems we can always ask what came prior to such and such etc...Its why people have such a problem when they are told not to ask what happened before the big bang because science would have us believe nothing happened as there was no time etc...

    Personally i find a closed loop, self-explanatory universe more appealing from a philosophical point of view. Something along the lines of that famous image of an eye that looks at it's own tail. Of course it still begs the question of what started the loop.
  16. Jul 18, 2008 #15
    Exactly! That's one good way of looking at the puzzle about the universe.
  17. Jul 18, 2008 #16
    Okay but if we pretend that there is a fundamental puzzle of origin which can never be solved, does not the looping self-explanatory universe close the door better than the tower of turtles type theories?

    If one considers Wheelers PAP, i believe it represents a brilliant way to explain us (biology), the universe and it also kind of makes it impossible for us to know anything other than the looping universe of which we are part of.

    If that makes any sense :smile:
  18. Jul 18, 2008 #17
    You are missing the point. I made no assumption. I replied to your own question where you ask how something that has always been there got there. This question makes no sense. If something has always been there then it never "got there" and the question of how it did that doesn't apply. Given a premise that something never happened, asking "how" it happened is sloppy reasoning.

    But back to the OP.

    Big Bang or not, there are only two possibilities. Either all of reality is completely deterministic or it isn't. If it is then yes, all our thoughts, emotions and decisions are determined by prior conditions and nothing can be done about it. If not then all our thoughts, emotions and decisions are spontaneous to some degree and nothing can be done about it.
    Last edited: Jul 18, 2008
  19. Jul 18, 2008 #18
    "Big Bang or not, there are only two possibilities. Either all of reality is completely deterministic or it isn't."

    Yes its easy to get into the "partly deterministic and partly non" paradox; when really its just one or the other because if there is any scope for non determinism then the whole model is non deterministic.

    If we accept what we are told about the state of the universe at the bb then it only consisted of one singular type of substance which went on to expand, cool and become clumpy through inflation. Other deterministic systems then were born from that initial state all with varying and different initial conditions of their own. So considering what we know about the "sensitvity of initial conditions" re chaos in deterministic systems - i dont see how the universe could be Deterministic.

    Also i find something really depressing and disturbing about the idea of a Determinsitic universe. That would be like we were programmed from start to finnish with zero non-linear ability. One predicted event after another - how horrible.
  20. Jul 18, 2008 #19
    I'm missing no point at all. I just understand that if something is there, then it leads to something else (that made it, or is related to it). Basically, the whole thing is about 'resources'. The 'things' that are here/there is a resource. And, how did the collection of these things....the resource become abundant. That is the question. And by saying that it was always abundant is not good enough, because what we want to know is how it became abundant and available. If you don't know, then just leave it at that.
  21. Jul 18, 2008 #20
    This shows once again what you are indeed missing: if it was always abundant then it never became abundant. You don't seem to understand this contradiction in your quest. Until you do, you will continue to ask the same meaningless question and keep yourself in the dark, scratching your head.
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