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Replace non-locality with infinite universes, which is more troubling? The article does touch on this question. Additionally, the article's aim was to demonstr

by xlm1717 10y ago

Replace non-locality with infinite universes, which is more troubling? The article does touch on this question. Additionally, the article's aim was to demonstrate that the ESSW does not contradict pilot-wave theory, not to show that pilot-wave theory explains the results better than alternative theories, and it demonstrated this by showing that there is no contradiction if you take in account nonlocality. The title is not misleading because the experiment described in the article does provide experimental support to the theory, support which ESSW aimed to take away. Importantly, it is not an experiment designed to show pilot-wave theory describes the results better than other theories.

btilly 10y ago
If the experiment does nothing to advance this theory over any competitor, or vice versa, how can you say that it provides experimental support to the theory? ESSW demonstrated that pilot-wave theory requires a weird form of non-locality. These experiments confirm that experiment requires the exact form of non-locality that ESSW required. Whether non-locality bothers you depends on your philosophical position, and is not affected by this experiment.
- mangeletti 10y ago
  You seem to suggest that support for a theory is meaningless unless it is absolutely conclusive. If that was the case, I'm pretty sure most of quantum physics would have been abandoned long ago. Until we know everything, is anything in theoretical physics really a zero-sum game? I think the problem is in the thinking quantum physicists must possess in order to believe in such a theory in the first place. I mean, the idea of, "if we don't know where it came from, it couldn't possibly be hidden information; it must therefor be 'random'" is absurdly egotistic in the first place.
  - btilly 10y ago
    I have no idea how you get from my words to, "...support for a theory is meaningless unless it is absolutely conclusive." What I said is that if the outcome of an experiment is predicted by two different theories, getting the expected result does nothing to help you decide between them. It happens to be the case that ANY experiment that is in accord with quantum mechanics is equally well explained by EVERY interpretation of quantum mechanics. The result is that most working physicists so not consider wondering about the right interpretation to be a useful scientific endeavor. Indeed most will gladly affirm that they belong to the "shut up and calculate" school of physics in practice. There are plenty of detailed questions within quantum mechanics which can be asked and answered by experiment. That is what scientists tend to do instead of debating interpretations.
- leeoniya 10y ago
  > If the experiment does nothing to advance this theory over any competitor, or vice versa, how can you say that it provides experimental support to the theory? Non-contradiction of existing theories can be seen as a prerequisite for support. As a restricted affirmation of non-wrongness perhaps.
  - jocro 10y ago
    >restricted affirmation of non-wrongness I think this is a really good way to put it, and an important criteria given the timescale over which these theories develop.
int_19h 10y ago
>> Replace non-locality with infinite universes, which is more troubling It's a question to the philosophers, not the scientists. There is no objective measurement for what "troubling" is. And if we don't start with any preconceived notions of how things _should_ work, then discovering that they work differently is not particularly troubling.
- matt_kantor 10y ago
  > It's a question to the philosophers, not the scientists. As discussed upthread, this is all philosophy. The popular interpretations of quantum mechanics are all experimentally equivalent, so we need to use elegance, intuitiveness, troubling-ness, etc to choose between them (and these can be highly personal). EDIT: After re-reading your comment I think I'm agreeing with you here.
  - eru 10y ago
    You can also use the `operational non-interpretation', and just use the math to calculate without worrying about what it `means'. (That's pretty close to the spirit of the Copenhagen interpretation, though.)
naasking 10y ago
> Replace non-locality with infinite universes, which is more troubling? The nature of the multiple universes is deply misunderstood. If you just think of the universe as a very large N-bit quantum computer, then the "multiple universes" are simply the superpositioned state of the computer itself. Nothing magical or non-physical about it. And since we are almost certainly living in a simulation [1]... ;-) [1] http://www.simulation-argument.com/simulation.html http://www.simulation-argument.com/simulation.html
- contravariant 10y ago
  The problem is that you wouldn't just need a superposition over a finite number of state, but for the theory to make sense the universe should be some superposition over all possible physical states. There are simply just too many possible states to meaningfully describe something like a distribution over them, which is what a superposition would be. Mathematics simply gives up when you try to integrate over an infinite number of dimensions.
  - naasking 10y ago
    I don't know where you are seeing a relevant infinity. At any given time, there are a finite number of particles each with a finite number of observables. It's a large number, but finite.
    - EGreg 10y ago
      How do you know? All we can see is the visible universe, and the horizon is receding faster than the speed of light. Where do you get that there are finitely many particles?
      - lmm 10y ago
        There was (to the best of our knowledge) a single big bang, since when energy is conserved. That gives us a total energy for the universe, which is large but finite, which puts an upper bound on the number of particles at any given time.
vorg 10y ago
> it demonstrated this by showing that there is no contradiction if you take in account nonlocality The article suggests pilot-wave theory "apparently" contradicts special relativity. We know the other interpretations "only" have a problem uniting with general relativity. Perhaps the core issue is Steinberg's quote in the last paragraph: “The universe seems to like talking to itself faster than the speed of light. I could understand a universe where nothing can go faster than light, but a universe where the internal workings operate faster than light, and yet we’re forbidden from ever making use of that at the macroscopic level — it’s very hard to understand.”
- btilly 10y ago
  The problem with general relativity is that general relativity can't be quantized. We have produced quite a few theories of gravity that can be quantized...then subjected them to experiment and they all failed. These days theorists are trying to create theories out of which both QM and GR could arise in the limit. An unbelievable amount of energy has gone into things like string theory and loop quantum gravity. True believers believe that a theory will be found..but they haven't succeeded yet. Back to pilot-wave theory. In special relativity, no inertial reference frame is privileged over the others. In pilot-wave theory one must be..but no experiment can reveal which one is. This is aesthetically ugly, but not actually a contradiction.
  - deleted 10y ago
    [deleted]
  - dnautics 10y ago
    > In pilot-wave theory one must be [preferred]..but no experiment can reveal which one is. Interestingly has this in common with tangherlini relativity... which, iirc, also has nonlocal effects (haven't done the math; am not sure) No one has combined bohm + tangherlini
  - deleted 10y ago
    [deleted]
  - acjohnson55 10y ago
ghgfhgfhn 10y ago
Everything that can be, is. Makes perfect sense to me.

by xlm1717 10y ago

btilly 10y ago

If the experiment does nothing to advance this theory over any competitor, or vice versa, how can you say that it provides experimental support to the theory? ESSW demonstrated that pilot-wave theory requires a weird form of non-locality. These experiments confirm that experiment requires the exact form of non-locality that ESSW required. Whether non-locality bothers you depends on your philosophical position, and is not affected by this experiment.

mangeletti 10y ago
You seem to suggest that support for a theory is meaningless unless it is absolutely conclusive. If that was the case, I'm pretty sure most of quantum physics would have been abandoned long ago. Until we know everything, is anything in theoretical physics really a zero-sum game? I think the problem is in the thinking quantum physicists must possess in order to believe in such a theory in the first place. I mean, the idea of, "if we don't know where it came from, it couldn't possibly be hidden information; it must therefor be 'random'" is absurdly egotistic in the first place.
- btilly 10y ago
  I have no idea how you get from my words to, "...support for a theory is meaningless unless it is absolutely conclusive." What I said is that if the outcome of an experiment is predicted by two different theories, getting the expected result does nothing to help you decide between them. It happens to be the case that ANY experiment that is in accord with quantum mechanics is equally well explained by EVERY interpretation of quantum mechanics. The result is that most working physicists so not consider wondering about the right interpretation to be a useful scientific endeavor. Indeed most will gladly affirm that they belong to the "shut up and calculate" school of physics in practice. There are plenty of detailed questions within quantum mechanics which can be asked and answered by experiment. That is what scientists tend to do instead of debating interpretations.
leeoniya 10y ago
> If the experiment does nothing to advance this theory over any competitor, or vice versa, how can you say that it provides experimental support to the theory? Non-contradiction of existing theories can be seen as a prerequisite for support. As a restricted affirmation of non-wrongness perhaps.
- jocro 10y ago
  >restricted affirmation of non-wrongness I think this is a really good way to put it, and an important criteria given the timescale over which these theories develop.

int_19h 10y ago

>> Replace non-locality with infinite universes, which is more troubling It's a question to the philosophers, not the scientists. There is no objective measurement for what "troubling" is. And if we don't start with any preconceived notions of how things _should_ work, then discovering that they work differently is not particularly troubling.

matt_kantor 10y ago
> It's a question to the philosophers, not the scientists. As discussed upthread, this is all philosophy. The popular interpretations of quantum mechanics are all experimentally equivalent, so we need to use elegance, intuitiveness, troubling-ness, etc to choose between them (and these can be highly personal). EDIT: After re-reading your comment I think I'm agreeing with you here.
- eru 10y ago
  You can also use the `operational non-interpretation', and just use the math to calculate without worrying about what it `means'. (That's pretty close to the spirit of the Copenhagen interpretation, though.)

naasking 10y ago

> Replace non-locality with infinite universes, which is more troubling? The nature of the multiple universes is deply misunderstood. If you just think of the universe as a very large N-bit quantum computer, then the "multiple universes" are simply the superpositioned state of the computer itself. Nothing magical or non-physical about it. And since we are almost certainly living in a simulation [1]... ;-) [1] http://www.simulation-argument.com/simulation.html http://www.simulation-argument.com/simulation.html

contravariant 10y ago
The problem is that you wouldn't just need a superposition over a finite number of state, but for the theory to make sense the universe should be some superposition over all possible physical states. There are simply just too many possible states to meaningfully describe something like a distribution over them, which is what a superposition would be. Mathematics simply gives up when you try to integrate over an infinite number of dimensions.
- naasking 10y ago
  I don't know where you are seeing a relevant infinity. At any given time, there are a finite number of particles each with a finite number of observables. It's a large number, but finite.
  - EGreg 10y ago
    How do you know? All we can see is the visible universe, and the horizon is receding faster than the speed of light. Where do you get that there are finitely many particles?
    - lmm 10y ago
      There was (to the best of our knowledge) a single big bang, since when energy is conserved. That gives us a total energy for the universe, which is large but finite, which puts an upper bound on the number of particles at any given time.

vorg 10y ago

> it demonstrated this by showing that there is no contradiction if you take in account nonlocality The article suggests pilot-wave theory "apparently" contradicts special relativity. We know the other interpretations "only" have a problem uniting with general relativity. Perhaps the core issue is Steinberg's quote in the last paragraph: “The universe seems to like talking to itself faster than the speed of light. I could understand a universe where nothing can go faster than light, but a universe where the internal workings operate faster than light, and yet we’re forbidden from ever making use of that at the macroscopic level — it’s very hard to understand.”

btilly 10y ago
The problem with general relativity is that general relativity can't be quantized. We have produced quite a few theories of gravity that can be quantized...then subjected them to experiment and they all failed. These days theorists are trying to create theories out of which both QM and GR could arise in the limit. An unbelievable amount of energy has gone into things like string theory and loop quantum gravity. True believers believe that a theory will be found..but they haven't succeeded yet. Back to pilot-wave theory. In special relativity, no inertial reference frame is privileged over the others. In pilot-wave theory one must be..but no experiment can reveal which one is. This is aesthetically ugly, but not actually a contradiction.
- deleted 10y ago
  [deleted]
- dnautics 10y ago
  > In pilot-wave theory one must be [preferred]..but no experiment can reveal which one is. Interestingly has this in common with tangherlini relativity... which, iirc, also has nonlocal effects (haven't done the math; am not sure) No one has combined bohm + tangherlini
- deleted 10y ago
  [deleted]
- acjohnson55 10y ago

ghgfhgfhn 10y ago

Everything that can be, is. Makes perfect sense to me.