the underlying assumptions rig the debate

I never said that things collapse "only when tied to an experiment".

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It seems to me that regardless of how you look at this, it still comes back the OP's point that the past is indeed mutable.

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At this point I can only note that you hvae tried quite hard to avoid discussing the sort of mutability required by the OP. From the last two posts it appears that the past is mutable only to the extent that the information required to reconstruct it is unavailable even with unlimited technical resources. Zeilinger asserts that the information that we have is immutable. If the past can only be changed in ways that do not affect the observed present then the OP is not correct at all.e

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So in your view, based on this statement, you believe he is saying the photon does not collapse until the detector is set up.

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I understand him as sayign that the photon will not collapse unless the apparatus is capable of measurign the path or if it leaves the path information determinable in principle after the photon leaves the apparatus.

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That does not help your point at all because if the collapse only occurs when we can determine what path the photon took, then almost no photons have ever collapsed at all.

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The reasoning appears to be absent. If it is true that most photons are in a superimposed state how would it hurt my point ?

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If you are saying that if via interaction, the photon does collapse,then the photon would have collapsed in the quantum eraser experiment without the detector being present

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Not so. If I understand Zeilinger correctly only interactions that would let us determine the path would collapse the state. The eraser prevents such an interaction from happening by destroying the information that would permit such an interaction to happen.t

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You earlier defined an uncollapsed state as being indeterminate. Now, I don't happen to agree with you since I think both the wave-like and particle-like paths are determined paths. Indeterminate would be to say no path was taken until observation, and that is whatsome physicists do say.

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To explain again, when I say that the path is indeterminate I mean that the wave-like behaviour is the result of the photon being "smeared" across all possible paths. (i.e. it is in a superposition of states where the states are the possible paths, rather than being in a single determinate state).

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But let's look at both propositions. First, if the path is indeterminate until someone sets up a detector that can determine a single path, then essentially all of pasy reality is indeterminate, right?

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Provided by "most of the past" you mean insignificant details like the exact path followed by individual photons. It doesn't mean that anything important is indeterminate. Remember that according to Zeilinger if the information needed to reconstruct any past event has not been completely eradicated then that event is immutable.So it seems as if there is no real hope for your OP here.The more so since, more than 200 posts later, you haven't dealt with the philosphical and theological issues I raised in my first post to this thread.s

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So you believe the photon travels as a wave until there is some means to determine a single path, and then it takes a single path, even if the measurement takes place after the photon has taken the path.

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No, I mean that the particle is "smeared" across all possible paths unless there is information that would restrict it to a single path.

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How is this not a change in the past? It moves from a superposition state to a single state, right? That is a change, correct?

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As I keep having to repeat it isn't the sort of change required by the OP.

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PaulK, every stance you have taken is inconsistent with observed reality.

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That certainly isn't true.

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You err by calling superposition indeterminate first off

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To claim that something in a superposition of states is in a single state would be a contradiction. Therefore it is wong to say that I "err" in rejecting such a view. If a particle is in a superposition of states it is because it is not in a single determinate state - it can only be described in terms of the probabilities of the various states in the superposition.

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...but regardless, you admit that the path changes from a superpositional state to a collapsed state and that this is retroactive. Your admission proves my point.

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I woul say that your refusal to defend the claims in the OP, instead settling on this lesser claim which I haven't disputed proves MY point. The claims of the OP lack scientific support. Or more specifically, to go back to the point which started this discussion of QM, it is reasonable to reject your views without rejecting quantum entanglement. Thus your claims of inevitable victory have been shown to be hollow and unfounded.
o

Strictly speaking all we can say from the experiments is that what we see at the far end is what we would see if the photon had taken a single path. What actually happens in between is not directly knowable Because it doesn't affect anything. And that is where your argument falls down - this phenomenon doesn't help your argument in the OP.
Edited by PaulK, : Provide reason for edit here. -->if (getCookie('UseUserTimeZone')) {printDateTime(1150870536000, 'US', '-', 4, 'AMPM');} else {document.write('06-21-2006 02:15 AM');}: Provide reason for edit here. ">http://

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This message is a reply to:
	Message 240 by randman, posted 06-20-2006 6:44 PM		randman has replied

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	Message 242 by randman, posted 06-21-2006 2:03 PM		PaulK has not replied
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