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Now do you think that propagating probability amplitude is a real physical thing?

by platz 7y ago

RangerScience 7y ago
Yes, actually! I just went looking and can't find it, but there was a science paper years ago about dropping.... hydrogen ions into liquid helium? The expectation was that the electrostatic forces would create "bubbles" of empty around the ions, which (the bubbles, not the ions) would then be detected when they reached the bottom. They found those bubbles. They also found many differently sized bubbles, all smaller, in a size distribution correlating to the probability that the ion would pierce the surface tension of the liquid. The interpretation was that the smaller bubbles were the "pieces" of the waveform that traversed the surface tension. This was taken as evidence the waveform is an actual thing that actually exists. I really wish I could find it...
- notanote 7y ago
  “Can the wave function of an electron be divided and trapped?” https://news.brown.edu/articles/2014/10/electron https://news.brown.edu/articles/2014/10/electron
leni536 7y ago
It doesn't make much sense to argue which parts of the equations are real physical. Having said that for me the Aharonov-Bohm effect proves the "reality" of the wave function. https://en.m.wikipedia.org/wiki/Aharonov%E2%80%93Bohm_effect https://en.m.wikipedia.org/wiki/Aharonov%E2%80%93Bohm_effect
TheOtherHobbes 7y ago
Yes, for mysterious values of "physical". Clearly there is a consistent ordering principle involved, just as there is in entanglement and related phenomena. But you can't look at a single photon/electron/whatever and get this contextual information out of what we know about the physical structure of the object itself. There is no physical marker we can read "inside" a photon that says it's entangled, or that it's passed through two slits by "interfering with itself". So the information - and probably the process itself - is contextual. We don't know where this information lives. But it has to exist somewhere, because we can see the effects of its operation very easily. So it's physical in the sense that we can see physical effects. Photons etc know what they're doing, and we can make excellent predictions about that behaviour. But the exact nature of the entities and relationships that makes this process work, and the way it maps to observable events and properties, remains a mystery. The obvious implication is that what we see isn't really fundamental. Neither field excitations nor the fields of QFT are the ground truth, and there's another layer of reality that generates them - and probably spacetime too. But that layer has some very unusual properties from our POV, and we're going to need some new metaphors to understand it.
wruza 7y ago
It’s interesting how classical knowledge offsets what we (me too) feel physical and what we don’t. If you think of particles like they’re hard repulsive spheres, does that make them more “real physical”? Why should matter be fundamental and not be emergent from phenomena that are unlike any of our experience?

Now do you think that propagating probability amplitude is a real physical thing?

by platz 7y ago

Now do you think that propagating probability amplitude is a real physical thing?

Yes, actually! I just went looking and can't find it, but there was a science paper years ago about dropping.... hydrogen ions into liquid helium? The expectation was that the electrostatic forces would create "bubbles" of empty around the ions, which (the bubbles, not the ions) would then be detected when they reached the bottom. They found those bubbles. They also found many differently sized bubbles, all smaller, in a size distribution correlating to the probability that the ion would pierce the surface tension of the liquid. The interpretation was that the smaller bubbles were the "pieces" of the waveform that traversed the surface tension. This was taken as evidence the waveform is an actual thing that actually exists. I really wish I could find it...

notanote 7y ago
“Can the wave function of an electron be divided and trapped?” https://news.brown.edu/articles/2014/10/electron https://news.brown.edu/articles/2014/10/electron

leni536 7y ago

It doesn't make much sense to argue which parts of the equations are real physical. Having said that for me the Aharonov-Bohm effect proves the "reality" of the wave function. https://en.m.wikipedia.org/wiki/Aharonov%E2%80%93Bohm_effect https://en.m.wikipedia.org/wiki/Aharonov%E2%80%93Bohm_effect

TheOtherHobbes 7y ago

Yes, for mysterious values of "physical". Clearly there is a consistent ordering principle involved, just as there is in entanglement and related phenomena. But you can't look at a single photon/electron/whatever and get this contextual information out of what we know about the physical structure of the object itself. There is no physical marker we can read "inside" a photon that says it's entangled, or that it's passed through two slits by "interfering with itself". So the information - and probably the process itself - is contextual. We don't know where this information lives. But it has to exist somewhere, because we can see the effects of its operation very easily. So it's physical in the sense that we can see physical effects. Photons etc know what they're doing, and we can make excellent predictions about that behaviour. But the exact nature of the entities and relationships that makes this process work, and the way it maps to observable events and properties, remains a mystery. The obvious implication is that what we see isn't really fundamental. Neither field excitations nor the fields of QFT are the ground truth, and there's another layer of reality that generates them - and probably spacetime too. But that layer has some very unusual properties from our POV, and we're going to need some new metaphors to understand it.

wruza 7y ago

It’s interesting how classical knowledge offsets what we (me too) feel physical and what we don’t. If you think of particles like they’re hard repulsive spheres, does that make them more “real physical”? Why should matter be fundamental and not be emergent from phenomena that are unlike any of our experience?