Recent content by PeterDonis

Everything I wrote down in that post (and in the post by @Morbert I was quoting from) is after the A/D measurement and before B/C enter the swap apparatus.

I've already said I'm taking no moderation actions in this thread. I was speaking as a participant. And the paper in question was the Ma paper, which you already agreed was difficult to follow. Also, there have been a number of posts about that paper since the one of mine that you quoted, which...

Newton didn't when he developed his mechanics, which he did in the mid-1660s, but didn't publish until his friend Edmund Halley badgered him into it in the 1680s. The Michelson Morley experiment, which was the first indication that the prevailing theory of light, which predicted that its speed...

There is: The Hilbert Space representation treats states as vectors in a vector space. The wave function representation treats states as functions on configuration space. It turns out that these are mathematically equivalent because the space of all possible wave functions turns out to be a...

There's no change in the Hilbert Space. There is a change in the wave function, or perhaps a better term if we're talking about the Hilbert Space formuiation would be "state vector" (what kets represent). The Hilbert Space is the vector space of all possible state vectors; that doesn't change...

With regard to the question I asked that you quoted, which is not "is the change a physical change", but "is it the same kind of physical change as if we measured the z-spin of particle 2". Which the quotes you gave from Norsen do not address at all. I asked because I think the question is...

Yes, I see what you're doing, and it makes it clearer what is actually being correlated in the Ma et al setup. I would say, based on your analysis, that the Ma et al setup makes everything behave as if photons 2 and 3 were in the appropriate Bell state as they come into the beam splitter marked...

Do you have a reference? This is not an interpretation I'm familiar with.

That's why I ruled out i); because it talks about the future swap causing the A/D correlation. As i) is phrased it says this creates the illusion of causation into the past, but the A/D measurement results are already known before the swap, and the swap can't change them. It can only adapt the...

"Correlation" might not be the best word to convey what has a causal effect. The point is that the A and D measurement results happen first, and those have a causal impact on what happens at the swap. In Bohmian mechanics, this is straightforward: those measurements cause an effective collapse...

Are you sure you don't have the choices mixed up? Here they are again: i) seems like the one that is problematic if you don't want backwards in time causation. ii) seems like the one that is straightforward forward in time causation: the A/D measurements happen first, before the swap, so that's...

I agree, and I certainly agree that that's the position Bohmian mechanics takes, which is why I chose ii). :wink:

Yes, agreed.

Do you think the wording I proposed in #114 means something different from the wording you proposed in the post I was responding to?

No. See post #13. The laws of physics plus the particular configuration of matter in the Earth.