JesseM said:If you don't want to discuss experimental observations now that's fine, but you seem to have been talking about them before when you disagreed with my comments about the observation of interference by saying "I'm sure it would be different, I would expect no interference pattern if mirrors were in place when the signal photons were detected, even if beam splitters were then swapped over before the idlers arrived." "I would expect no interference pattern" is a statement about what would be observed, not about how we interpret our observations. If you don't want to stand by that statement no problem, but that was the statement that led to this particular tangent of the discussion.
"No friggin idea" about what? I think any experiment involving correlations between entangled particles has potential to be explained locally via a many-worlds type interpretation, see [post=1557143]this post of mine[/post] for a simple "toy model" explaining conceptually how this could work. I looked at your webpage and you don't seem to have a very clear model, you seem to include some concept of "collapse" but you don't seem to give an answer to the problem I raised earlier about models with collapse:unusualname said:Ok, I didn't even look at the experiment, maybe I got something mixed up, but understand this: if the setup is changed during the flight time of the photons you have no friggin idea do you, whereas I can EXACTLY explain it.
then you have to explain what exactly causes the "collapses" to occur if you want to say that the measuring-system obeys the same laws as the system being measured.
The point is I could not be bothered with your experiment you linked to, really, is it that different to any other **** we've been subjected to over the years?JesseM said:"No friggin idea" about what? I think any experiment involving correlations between entangled particles has potential to be explained locally via a many-worlds type interpretation, see [post=1557143]this post of mine[/post] for a simple "toy model" explaining conceptually how this could work. I looked at your webpage and you don't seem to have a very clear model, you seem to include some concept of "collapse" but you don't seem to give an answer to the problem I raised earlier about models with collapse:And from your non-response to my comment about your statement "I'm sure it would be different, I would expect no interference pattern if mirrors were in place when the signal photons were detected, even if beam splitters were then swapped over before the idlers arrived", I take it you are indeed abandoning this claim, but for some reason are refusing to acknowledge this explicitly? There's no shame in retracting a statement you made too hastily y'know, everyone does this from time to time, but it's kind of odd when someone is repeatedly pressed on a comment but they just won't say anything more about it one way or the other.
On your side about what? I don't like any interpretation that treats "collapse" as real, seems absurd to me given what's known about decoherence.unusualname said:f this was my first or early response, on the forum of course it would be rude, but it's not, I've argued out (practically alone) the unbelievers on the quantum physics forums for over a year
. You've stood there in the sidelines with your hope for everett mwi, but come on, man up, I know you're on my side but you don't like the cak-handed way I'm doing it. I*'m sure you think I've surely got it.
I don't get it, what "classical conditions" would be in the delayed choice quantum eraser (feel free to assume it's performed in space too) that wouldn't be in the Walborn setup?unusualname said:The reason I can't argue your experiments is because there are a lot or classical conditions with phase relationships and absorption/reflection laws that can brought into play to really complicate things, and I don't want to do that (because it's pointless). Better two satellites in space in something like the Walborn setup with polarisers placed during the transit time of the photons.
JesseM said:On your side about what? I don't like any interpretation that treats "collapse" as real, seems absurd to me given what's known about decoherence.
I don't get it, what "classical conditions" would be in the delayed choice quantum eraser (feel free to assume it's performed in space too) that wouldn't be in the Walborn setup?
What "classical phase relationships" are significant in the delayed choice quantum eraser? Are you referring to the fact that the D0/D1 and D0/D2 interference patterns are out-of-phase so their sum is a non-interference pattern? If so I don't see what's "classical" about this, and in any case I said near the beginning of the thread that I would guess something similar would be true in the Walborn setup if you looked at the interference patterns at Ds for different specific positions of Dp...for each specific position of Dp you would see an interference pattern at Ds, but if you summed all the interference patterns for different positions of Dp I bet they would add up to a non-interference pattern.unusualname said:The walborn setup doesn't allow any possibility of classical phase relationships being in any way significant
On your side about what? I don't like any interpretation that treats "collapse" as real, seems absurd to me given what's known about decoherence.
I don't know what that mean. Again, the Schrödinger equation gives the evolution of the quantum state vector, which only assigns complex amplitudes to different possible observable results, you can only turn those into real-valued probabilities by invoking a "collapse" due to measurement with the Born rule. And "collapse" does not follow from the deterministic evolution under the Schrödinger equation, it's an entirely separate assumption.unusualname said:Decoherence has been observed in exactly the way that an ontological probability evolving according to scrhoedinger evolution would predict.
JesseM said:What "classical phase relationships" are significant in the delayed choice quantum eraser? Are you referring to the fact that the D0/D1 and D0/D2 interference patterns are out-of-phase so their sum is a non-interference pattern? If so I don't see what's "classical" about this, and in any case I said near the beginning of the thread that I would guess something similar would be true in the Walborn setup if you looked at the interference patterns at Ds for different specific positions of Dp...for each specific position of Dp you would see an interference pattern at Ds, but if you summed all the interference patterns for different positions of Dp I bet they would add up to a non-interference pattern.
There is no "collapse", trust me. The universe just evolves and we have to measure it to see what it evolved to. (Controversially , I suggest we can change the unitary evolution with free-will, but let's not go there now)JesseM said:I don't know what that mean. Again, the Schrödinger equation gives the evolution of the quantum state vector, which only assigns complex amplitudes to different possible observable results, you can only turn those into real-valued probabilities by invoking a "collapse" due to measurement with the Born rule. And "collapse" does not follow from the deterministic evolution under the Schrödinger equation, it's an entirely separate assumption.
Yes, I understand that. My point is that there need not be any interference pattern in the total pattern of photons at Ds even with the polarizer in front of Dp, because it's only when you look at the subset of signal photons at Ds whose idlers were detected at a particular position that you get interference, if you were to add up all the different subsets in an expanded experiment where the Dp detector could detect idlers at a range of positions, then all those interference patterns would add up to a non-interference pattern. If the total pattern of signal photons (without doing any coincidence matching) could show interference depending on whether a polarizer was in place in front of Dp, then this would allow for FTL signalling, but just as in the delayed choice quantum eraser this is avoided by the fact that interference is only seen in coincidence-matched subsets.unusualname said:eh? So what, you have to sum for the specific position of Dp in each case, have you actually studied the experiment?
No need to be condescending, I understand the experiment but was making a point about a variant that would help explain why looking at the pattern of photons at Ds doesn't give you any FTL knowledge about whether a polarizer was placed in front of Dp.unusualname said:It wouldn't make sense to sum over different positions of Dp for specific position of Ds,
geez, this is an undergrad experimet, it's not so hard to analyse.
That doesn't really make any sense. If you treat the measurer as a quantum system and allow everything to evolve according to the Schrödinger equation, then measurement will simply entangle the measurer with the system being measured, causing the measurer to be in a macroscopic superposition like Schrödinger's cat. That would be OK if you were advocating a many-worlds type interpretation, but if you want there to be a single definite outcome each time you can't just have evolution according to the Schrödinger equation at all times.unusualname said:There is no "collapse", trust me. The universe just evolves and we have to measure it to see what it evolved to. (Controversially , I suggest we can change the unitary evolution with free-will, but let's not go there now)
JesseM said:That doesn't really make any sense. If you treat the measurer as a quantum system and allow everything to evolve according to the Schrödinger equation, then measurement will simply entangle the measurer with the system being measured, causing the measurer to be in a macroscopic superposition like Schrödinger's cat. That would be OK if you were advocating a many-worlds type interpretation, but if you want there to be a single definite outcome each time you can't just have evolution according to the Schrödinger equation at all times.
Calm down man, how would you expect me to know that's what you mean when you just got through saying everything evolves according to the Schrödinger equation? (you said your model involved 'an ontological probability evolving according to scrhoedinger evolution') If there are random quantum jumps, then it's not actually true that the Schrödinger equation determines the dynamics at all times. And saying the jumps are "random" is not very specific, is there supposed to be a probability distribution determining the likelihood that another quantum jump will happen a given time after the previous one? Or are you invoking consciousness/free will to determine when jumps occur? What actually happens to the quantum state vector during the jumps, does it involve jumping onto an eigenstate of some observable (or a complete set of commuting observable), if so it is always a position eigenstate or can the whole universe jump into a momentum eigenstate where there is maximal uncertainty in position, and if so what would that be like? If it does involve jumping into an eigenstate, you need to realize this is exactly what is meant by "collapse", so you were wrong to say earlier 'There is no "collapse", trust me'. If it doesn't involve jumping into an eigenstate, what prevents the universe from just continually jumping into states that involve macroscopic superpositions like Schrödinger's cat? You need specific answers to these kinds of questions for your idea to be remotely well-defined.unusualname said:Jesus Christ, the WHOLE universe (you, me, every friggin thing) evolves unitarily seeded by RANDOM quantum "jumps".
JesseM said:Calm down man, how would you expect me to know that's what you mean when you just got through saying everything evolves according to the Schrödinger equation? (you said your model involved 'an ontological probability evolving according to scrhoedinger evolution') If there are random quantum jumps, then it's not actually true that the Schrödinger equation determines the dynamics at all times. And saying the jumps are "random" is not very specific, is there supposed to be a probability distribution determining the likelihood that another quantum jump will happen a given time after the previous one? Or are you invoking consciousness/free will to determine when jumps occur? What actually happens to the quantum state vector during the jumps, does it involve jumping onto an eigenstate of some observable (or a complete set of commuting observable), if so it is always a position eigenstate or can the whole universe jump into a momentum eigenstate where there is maximal uncertainty in position, and if so what would that be like? If it does involve jumping into an eigenstate, you need to realize this is exactly what is meant by "collapse", so you were wrong to say earlier 'There is no "collapse", trust me'. If it doesn't involve jumping into an eigenstate, what prevents the universe from just continually jumping into states that involve macroscopic superpositions like Schrödinger's cat? You need specific answers to these kinds of questions for your idea to be remotely well-defined.
Anyway my critique about decoherence still applies, I find it very inelegant to assume objective "jumps" that just happen to behave exactly like the records you would get if you assumed no jumps until the very end of a long series of experiments, just continuous evolution of the quantum state vector according to the Schrödinger equation, with a final "jump"/collapse in which the measurement records go to a classical state. In this case the records will appear to show a series of previous collapses when the small quantum system interacted with a large measuring instrument, due to decoherence, even though none actually happened earlier in this model. The fact that decoherence would give "fake" collapses that happen to look just like real collapses seems too coincidental to me.