4 ms·

How does this not enable ftl information transmission? It seems to me that you have a valve that instantly opens/close a different valve at an arbitrary distan

How does this not enable ftl information transmission? It seems to me that you have a valve that instantly opens/close a different valve at an arbitrary distance.

Natanael_L 11y ago
You can't control what the value will be or when it will open/close. It isn't a detectable "push event" like in computer systems.
hsk 11y ago
Because whether the spin is up or down when you observe it is completely random. Both observers at either end would believe they looked at it first without any other information, and the stream of bits would be completely random AND 100% correlated with other.
- Paradigma11 11y ago
  Ok, so you will always have perfect correlation and since you spun the polarizer after the photons started moving that implies spooky action at a distance. right?
JulianMorrison 11y ago
Many worlds makes it clear how it can't: because there is no FTL transmission. There is only stuff that has been pulled into the superposition (seeing a definite answer) and stuff that hasn't yet (for which both answers are still superposed). When the latter comes in contact with the former, it enters the superposition, which from the outside perspective is a split. From the inside perspective, it looks like "the superposition collapsed". From the outside, one side gets "open" and the other gets "closed". From the inside, this looks like getting a random answer. You can see intuitively why this can't convey information. You always get both answers (in different "worlds").
- TheOtherHobbes 11y ago
  That doesn't really explain the mechanics of the splitting process. It's "And to explain this, we postulate that a whole new universe appears fully formed out of nowhere, with an identical history but a distinguishable future, because it does." I suppose it's possible. But it doesn't seem very parsimonious - because you effectively have to double the energy in the multiverse for every distinguishable quantum event. Does conservation of energy not apply in the multiverse? Are universes - as many as you need - free at point of sale?
  - david_ar 11y ago
    Splitting is just a metaphor for a superposition of macroscopic states. There's no extra mechanics involved.

How does this not enable ftl information transmission? It seems to me that you have a valve that instantly opens/close a different valve at an arbitrary distance.

Natanael_L 11y ago

You can't control what the value will be or when it will open/close. It isn't a detectable "push event" like in computer systems.

hsk 11y ago

Because whether the spin is up or down when you observe it is completely random. Both observers at either end would believe they looked at it first without any other information, and the stream of bits would be completely random AND 100% correlated with other.

Paradigma11 11y ago
Ok, so you will always have perfect correlation and since you spun the polarizer after the photons started moving that implies spooky action at a distance. right?

JulianMorrison 11y ago

Many worlds makes it clear how it can't: because there is no FTL transmission. There is only stuff that has been pulled into the superposition (seeing a definite answer) and stuff that hasn't yet (for which both answers are still superposed). When the latter comes in contact with the former, it enters the superposition, which from the outside perspective is a split. From the inside perspective, it looks like "the superposition collapsed". From the outside, one side gets "open" and the other gets "closed". From the inside, this looks like getting a random answer. You can see intuitively why this can't convey information. You always get both answers (in different "worlds").

TheOtherHobbes 11y ago
That doesn't really explain the mechanics of the splitting process. It's "And to explain this, we postulate that a whole new universe appears fully formed out of nowhere, with an identical history but a distinguishable future, because it does." I suppose it's possible. But it doesn't seem very parsimonious - because you effectively have to double the energy in the multiverse for every distinguishable quantum event. Does conservation of energy not apply in the multiverse? Are universes - as many as you need - free at point of sale?
- david_ar 11y ago
  Splitting is just a metaphor for a superposition of macroscopic states. There's no extra mechanics involved.