Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

QM uncertainty, it couldn't have been any other way

  1. Jul 20, 2006 #1
    I'm relatively new to QM and find it very interesting. At first it seemed odd that particles could behave with such uncertainty, but I then thought that it couldn't have been any other way.

    Here is my reasoning.

    If there was a mathematical way to determine the exact position and momentum of all particles then we could predict the exact position/momentum of resulting collisions of particles. If this was the case, then we could in theory predict future events with a very very very complex mathematical equation. For example, you would be able to, in theory, calculate tomorrows loto numbers, based on quantum collisions occuring today.This would then mean that the future is fixed and completely predictable to infinity. We would then all just be pupets carrying out a pre-determined destiny.

    The uncertainty of QM adds just enough randomness to break us free from a pre defined destiny making the future unknown.

  2. jcsd
  3. Jul 20, 2006 #2
    Regardless if there is determinism or not, your reasoning is not valid:

    X = The future is determined.
    Y = We would all be pupets.

    So you are saying "if X then Y"

    So how does show that X is false?

    Would could be puppets afteral and not know it right? :smile:
  4. Jul 20, 2006 #3


    User Avatar
    Science Advisor
    Gold Member

    I think I see the point. If there was no uncertainty (HUP), then we might conclude there is predestination. But we observe uncertainty, therefore we don't know one way or the other.

    Of course, there are those iinterpretations of QM - I think Bohmian Mechanics would qualify - in which the uncertainty is an artifact of our lack of knowledge. As I understand it, non-local interactions provide the missing ingredients to the state equation and a mechanistic view is possible. I guess in that line of reasoning, the OP's conclusion does not hold.
  5. Jul 20, 2006 #4

    Doc Al

    User Avatar

    Staff: Mentor

    Wouldn't that just make us puppets of quantum randomness? :smile:
  6. Jul 20, 2006 #5
    Wouldn't symmetry breaking prevent determinism, irregardless of uncertainty? Or is symmetry breaking somehow dependent on it?
  7. Jul 20, 2006 #6
    Dr Chinese
    Congratulations on completing your first millennium of posts, with # 1000 here.
    May the next millennium be even more interesting.
    Looking forward to seeing more of yours.

    On the issue of determinism and predestination, I’m satisfied that reality is not deterministic or has predetermined all our comments here.
    If deterministic I don’t think something as simple as generating verifiable random numbers would be so easy, nor making judgments about just how random they truly are.

    However, I’m NOT satisfied that the details of any our current theories are correctly identifying why reality is not predetermined. And not knowing if it is due to a UNCERTAINTY or a definable LACK OF KNOWLEDGE of something (maybe an unknowable something) is a good way to put it.

    Finding and verifying why is a much bigger step that producing various but different explanations how predetermined is not true. There are too many different ways to explain it, to be able to claim we know which way is the correct explanation. And that leaves open the possibility that none are correct, including HUP.
  8. Jul 20, 2006 #7
    You do not need to go to Quantum Uncertainty to acheive unpredictablilty. In a nonlinear system, any error in measuring the initial conditions eventually becomes larger than what you are trying to measure.
  9. Jul 20, 2006 #8
    Does the puppet imply a puppeteer? :confused:
  10. Jul 20, 2006 #9

    The "puppeteer" or "big guy" consciously added uncertainty in QM so that the measurement error was large enough to prevent a deterministic future.

    I guess, what is the point of creating a universe if from day one the future is deterministic? Add a dash of uncertainty and then watch how it unfolds. :smile:

    I guess the comments of us not really knowing if uncertainty is truly just that, are valid. Perhaps we just don't know all the variables.

  11. Jul 21, 2006 #10
    My next comment will definitely get this thread moved!

    But I don't think random genetic mutation is sufficient to account for evolution. When I see fractal patterns, I get a hunch that there is some deeper pattern than just randomness.

    I am NOT saying intelligent design or anything like that, I am just saying I think there is something else beneath the surface that we haven't figured out yet.
  12. Jul 21, 2006 #11


    User Avatar
    Staff Emeritus
    Gold Member
    Dearly Missed

    Well, you were right:biggrin:
  13. Jul 21, 2006 #12


    User Avatar
    Staff Emeritus
    Gold Member

    Of course random genetic mutation is not sufficient to account for evolution. It is simply one mechanism by which variation is introduced into a population. In order to account for evolution, we need to introduce other mechanisms by which variation is introduced (although all are ultimately derivative on mutation historically speaking), as well as a mechanism for decreasing variation, which is the entire idea of natural selection.

    I'm going to assume this was moved to value theory in error. A discussion of the teleology of quantum indeterminacy seems metaphysical to me, so off to metaphysics.
  14. Jul 21, 2006 #13
    Did the puppeteer create uncertainty for its sake, our sake, or both? Does God play dice, or just allow us to?

    I think the answer can be found in thinking about time. If God is subject to time, then God is playing dice. If time is subject to God, then we are the ones playing dice.

    I vote for God not playing dice. But does it allow us to play dice or is it necessary that we do?

    I think if there was no future (unknown), then all things would happen at once, they would all have to be one thing, and there would be no space or mass.

    God would be the one thing inside of itself (what else?), so God would also be outside of itself, which means God would be relative and there would be no existence whatsoever.
  15. Jul 23, 2006 #14
    Your post confuses a number of issues.

    Firstly, determinability (ability to predict the future) is quite a different beast to determinism (whether the future is "fixed"). Even if QM were 100% deterministic, it does not follow that the world would be determinable - for 2 main reasons : Chaos and self-referentiality.

    Secondly, the empirical data from QM show that the world is indeterminable - they do NOT show conclusively that the world is indeterministic. There are non-local hidden variables interpretations of QM which are entirely deterministic; and there is no indeterministic interpretation (that I am aware of) which explains the ontology behind delayed-choice quantum eraser experiments.

    Thirdly, the introduction of indeterminism allows for "alternative possibilities" (makes the future unknown), but to assume from this that we have any freedom to choose those possibilities is incoherent - introduction of random effects into the world simply makes our acts arbitrary. A deterministic world would be more in keeping with our desire to control our actions.

    Best Regards
    Last edited: Jul 23, 2006
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook