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

Logic and causality?

  1. Aug 3, 2008 #1
    Logic and causality???

    Hi, what implications does quantum physics have on the realm of causality? For instance, due to the wave-particle duality, is it reasonable to say that the universe can be explained through causality? How does this change the concept of 'logic'?

    Intuitively, we believe that one thing causes another, no matter how complex or convoluted a system is. But with quantum physics, to what extent does the causal/logical model of the universe break down?

    I can't decide what to believe, maybe human language itself cannot explain what is going on.
  2. jcsd
  3. Aug 4, 2008 #2


    User Avatar

    philosophical reflection

    Quantum mechanics has abandoned the idea of deterministic causation between events, but it certainly has not abandoned causation. Instead it makes use of a kind of probabilistic causation.

    Ie. he intedeterminism at event level, is restored at probability level. So that probabilities of any event evolve deterministically.

    What implications this has for logic is a interesting question. In the strict sense I wouldn't not sure it has any hard implications, but it may have suggestions. I tend to make associations between physical interactions and inductive reasoning, and then you may come up with the wild idea that inductive logic is more fundamental than deductive. But I think many find that crazy, but the idea would be that in a certain sense deductive logic is inductive, if you consider the axioms to be chosen in a way that one might argue is nothing but a kind of induction. And once you've chosen, then you can forget about the choice ans pretend that you are doing hard deductions. But first the axioms must be picked.

    But the above is highly personal reflections, not anything that follows from quantum theory, and neither is it impliciations.

  4. Aug 4, 2008 #3


    User Avatar

    Re: Logic and causality???

    I think the way to go is to analyze this further. Why do we "believe" that one thing causes another? Or rather, why have we "come to believe" this?

    So rather than some prejudiced opinion that "everything must have a deterministic case", usually I think you have some evidence at hand, from which you form this belief by induction. But if you try to assign confidence levels to your beliefs, then it seems it's all about degrees of confidence.

    There is clearly an utility of beeing able to predict things, so the emergence of causal relations, although "fuzzily probabilistic" rather than deductive seems plausible.

    This view of things, suggets to focus on understanding the logic of induction in this context. Or the logic of belief and how it is subject to revision.

    What I argue in favour of here though, is a version of the bayesian inspired interpretations of QM, but what I find interesting that taking this serious, it seems to suggest improvements to the existing formalism. This is the possible utility that drives my interest in this angle.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook