3 ms·

Correction: it has to be accessible to a single particle, but the information could be non-localized across the whole system, since your particle is itself fair

Correction: it has to be accessible to a single particle, but the information could be non-localized across the whole system, since your particle is itself fairly non-localized, and arguably has weakly interacted with the various devices along the way, meaning that Im not sure we can fully disentangle the wave-equation for the photon from the equations for the splitters. This could easily be the photon "borrowing" bits from the splitter, by sharing a non-local value with it, which carries the split path information for both. Which is just to say that the system (in full) has to be able to contain a number of bits sufficient for that, which your setup does.

lisper 10y ago
> Im not sure we can fully disentangle the wave-equation for the photon from the equations for the splitters That doesn't matter. The two sides of the experiment are space-like separated, and the splitters on each side are light-like separated. There is no place the information can possibly be other than in the photons.
- SomeStupidPoint 10y ago
  ...except non-local variables. Which is why I keep mentioning non-locality. I don't think words are working and I'm not sure I understand your point fully. Could you draw a diagram? Specifically, the apparatus and where you think the requirement for information occurs. I really do want to understand your point, because it's an interesting argument, even if I'm not sure I agree.
  - lisper 10y ago
    > I don't think words are working Indeed. I have no idea what you mean by "non-local variable." You should read this: http://www.scottaaronson.com/democritus/lec11.html http://www.scottaaronson.com/democritus/lec11.html just to make sure we're on the same page about the basics. (Pay particular attention to the part starting with "No-go theorems galore".)
    - SomeStupidPoint 10y ago
      Could you point out what you think that has to do with locality? It mentions it once, to assert it as a desired axiom (and incorrectly assert that QM can be local, which it can't be). I also would argue that GR supports non-local theories well enough, in that the actual geometry can appear macro-Euclidean (or other nice space) while containing micro-bridges which break the locality structure for the "nice" macro space. A non-local value is any value which can impact things at super-luminal speed (generally, instantaneously). Of course, I would argue that the non-locality is only apparent, and we're simply seeing the shape of things very wrong because of how brains work, the information reaches us, etc.
      - lisper 10y ago
        > A non-local value is any value which can impact things at super-luminal speed Ah. Those are ruled out by relativity. If you can send information faster than light, then you can send information backwards in time and violate causality.

lisper 10y ago

> Im not sure we can fully disentangle the wave-equation for the photon from the equations for the splitters That doesn't matter. The two sides of the experiment are space-like separated, and the splitters on each side are light-like separated. There is no place the information can possibly be other than in the photons.

SomeStupidPoint 10y ago
...except non-local variables. Which is why I keep mentioning non-locality. I don't think words are working and I'm not sure I understand your point fully. Could you draw a diagram? Specifically, the apparatus and where you think the requirement for information occurs. I really do want to understand your point, because it's an interesting argument, even if I'm not sure I agree.
- lisper 10y ago
  > I don't think words are working Indeed. I have no idea what you mean by "non-local variable." You should read this: http://www.scottaaronson.com/democritus/lec11.html http://www.scottaaronson.com/democritus/lec11.html just to make sure we're on the same page about the basics. (Pay particular attention to the part starting with "No-go theorems galore".)
  - SomeStupidPoint 10y ago
    Could you point out what you think that has to do with locality? It mentions it once, to assert it as a desired axiom (and incorrectly assert that QM can be local, which it can't be). I also would argue that GR supports non-local theories well enough, in that the actual geometry can appear macro-Euclidean (or other nice space) while containing micro-bridges which break the locality structure for the "nice" macro space. A non-local value is any value which can impact things at super-luminal speed (generally, instantaneously). Of course, I would argue that the non-locality is only apparent, and we're simply seeing the shape of things very wrong because of how brains work, the information reaches us, etc.
    - lisper 10y ago
      > A non-local value is any value which can impact things at super-luminal speed Ah. Those are ruled out by relativity. If you can send information faster than light, then you can send information backwards in time and violate causality.