Slashdot Mirror


Entanglement Could Be a Deterministic Phenomenon

KentuckyFC writes "Nobel prize-winning physicist Gerard 't Hooft has joined the likes of computer scientists Stephen Wolfram and Ed Fredkin in claiming that the universe can be accurately modeled by cellular automata. The novel aspect of 't Hooft's model is that it allows quantum mechanics and, in particular, the spooky action at a distance known as entanglement to be deterministic. The idea that quantum mechanics is fundamentally deterministic is known as hidden variable theory but has been widely discounted by physicists because numerous experiments have shown its predictions to be wrong. But 't Hooft says his cellular automaton model is a new class of hidden variable theory that falls outside the remit of previous tests. However, he readily admits that the new model has serious shortcomings — it lacks some of the basic symmetries that our universe enjoys, such as rotational symmetry. However, 't Hooft adds that he is working on modifications that will make the model more realistic (abstract)."

10 of 259 comments (clear)

  1. I knew it. by Anonymous Coward · · Score: 5, Funny

    Free will is a sham. Of course, believe whatever you will. It's not like you have a choice.

    1. Re:I knew it. by Chris+Burke · · Score: 5, Insightful

      Free will is a sham. Of course, believe whatever you will. It's not like you have a choice.

      Dude, if you were counting on the non-determinism of quantum entanglement to save the concept of free will, then you were out on a limb to begin with. How is randomly following the rules of the universe any more a matter of "will" than deterministically following them?

      You could try to rely on a seriously weird and unlikely interpretation of QM which is basically a pun (measurement -> observation -> observer -> sentient observer), but then you're using the concept of sentience/free will influencing quantum events to explain how sentience/free will is possible in the first place. Maybe it's possible, but it's quite a long shot to be basing your whole concept of self awareness on.

      I have free will because as far as I can tell I exercise it. In a pure philosophical sense you could never prove you have it even if we somehow did show that QM is influenced by "observers". But that act of faith has worked well enough for me. I'm certainly going to live my life as though I have free will, and if I'm only "automatically" making that choice, then so be it.

      --

      The enemies of Democracy are
  2. Hidden controlled by Hidden by Twillerror · · Score: 4, Insightful

    I've often been skeptical of the idea that you could disproove a hidden variable. The hidden variable itself could be dynamic controlled by another hidden variable.

    I guess I just assume that there is more we don't know about the universe that we do know about it.

    1. Re:Hidden controlled by Hidden by blueg3 · · Score: 5, Informative

      It's not really valid, though; it makes a false distinction between "a hidden variable" and "a hidden variable controlled by another hidden variable" as if they were different. Bell's theorem covers (or at least appears to cover) any additional information or state, regardless of the theory or process involved, provided that state is "attached" to the entangled particles (that is, it's local).

  3. "Backwards" Causation by etymxris · · Score: 5, Interesting

    Bell's inequalities fall apart if current particles can "know" about future measuring devices. However, for particle physics, neither direction of time is privileged. Particles are just as likely to be influenced by future interactions as they are by past interactions. Because of this, there is no "action at a distance". Influences travel along the backwards light cone and remain perfectly relativistic.

    This simple, straightforward solution has been largely ignored.

    Note that most interpretations of quantum mechanics are explicitly time asymmetric due to the "collapse" caused by observation. Cramer's transactional theory is an exception, it is symmetric and there is no collapse, but it doesn't get much attention.

  4. Re:Come up with a generic theory... by Anonymous Coward · · Score: 4, Insightful

    Come up with a generic theory...And then tweak it to match reality.
    I'm afraid people do that all the time, each one new and different.

    Uh...yeah. That is how the scientific process is supposed to work. You form a hypothesis based on what you know already, you test it, and as the results of your tests roll in, you modify the hypothesis accordingly. Form and then tweak. This is the essence of all scientific progress we have made to date.

    Why do you have a problem with this? I'd say the proof is in the pudding.

    But why do they bother? We already have the ultimate "parameterize and tweak the theory to match reality" theory in String Theory, so why bother with anything else?

    Because string theory lacks evidence, and we don't have the technological means to gather much evidence for it (at present). Also, at present, the theory fails to offer much utility (we can't build any useful devices based on string theory).

    Your attitude sounds a bit scarey. I read it as, "we already KNOW the truth, so why continue looking?" This very attitude inhibited scientific progress for most of human history. I wonder if it also inhibits you?

  5. Dammit, there goes the planet. by BigGar' · · Score: 5, Funny

    If Stephen Wolfram turns out to be correct, his ego will collapse into a singularity form the rapid mass inflation it will under go, taking the Earth with him.

    --


    Shop smart, Shop S-Mart.
  6. Its just a matter of modeling by Brain-Fu · · Score: 5, Insightful

    When you model the universe in terms of will-less mechanisms, you will (amazing!) discover that free will is a logical impossibility.

    Trying to model free will in terms of physics is like trying to describe the combustion engine using only the words found in a book on home gardening.

    The only reason some people find this personally problematic is because they have decided that our current model of physics is also the concrete, accurately-represented holy truth. In fact, our current model is just an abstract representation of something we can't see, and it is just the best we've come up with so far (in fact, any scientist worth his salt will predict that our models will change in the future).

    So the quantum-mechanical model of the universe is incompatible with any free-will-is-real model of the universe. So what? This incompatibility doesn't make either theory right or wrong. The evidence for each theory is all that matters.

    As Epicurus (one of the fathers of the modern scientific method) advised, "if several theories are consistent with the observed data, retain them all."

  7. 3 choices by mbone · · Score: 4, Informative

    Hidden variables in this case should be thought of as a hidden micro-states. A hidden variable theory would have quantum mechanics be something like thermodynamics; i.e., a theory that is not really basic, but appears so as we cannot see the fine scale true reality. Einstein was convinced that this had to be the case.

    The tests of Bell's Theorem shows that no locally causal hidden variable theory is viable. This says basically that one of these must be the case

    There are no hidden variables (i.e., true quantum uncertainty applies, and quantum mechanics is correct).

    The speed of Light can be violated (i.e., there are hidden states that can exchange information faster than the speed of light). This implies, by the way, causality failures would be possible, so that in principle you could do something like kill your grandfather and prevent your own existence.

    There is action at a distance (i.e., the theory is non-local).

    There has long been a viable theory, that of Bohm, that replicates normal quantum mechanics. It's non-local.

    I cannot tell from a read of the article (and without seeing the underlying paper) if 't Hoof has a non-local theory or just how he stays consistent with Bell's Theorem.

  8. Ask an alchemist. by Anonymous Coward · · Score: 4, Insightful

    Or maybe a Sorceror.
    Or maybe a Christian.

    Modeling the universe in terms of magic is what humanity has been doing for most of recorded history.

    Modeling the universe in terms of mechanical interactions of particles or waves is the new-and-cool. And we are still getting our heads around how to do it.