Register | Sign In


Understanding through Discussion


EvC Forum active members: 65 (9162 total)
2 online now:
Newest Member: popoi
Post Volume: Total: 915,821 Year: 3,078/9,624 Month: 923/1,588 Week: 106/223 Day: 4/13 Hour: 0/2


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   the underlying assumptions rig the debate
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 76 of 246 (322866)
06-18-2006 10:06 AM
Reply to: Message 43 by randman
06-18-2006 12:19 AM


Re: not misunderstanding "observe" here
randman writes:
Furthermore, I think you are focussing on the technical difficulties with building quantum computers to somehow reject 80 plus years of development of quantum theory and hard experiments.
Iblis never expressed any doubt about the possibility of quantum computers. What he explained to you is that it is a misinterpretation of entanglement to believe you can transmit information faster than the speed of light. You can't.
Iblis also never rejected "80 plus years of development of quantum theory and hard experiments." He's pointing out your misinterpretation. It is your own viewpoint which is the one that is contrary to contemporary understanding of quantum theory.
Edit to add you also make a common fallacy of claiming that somehow there is a misunderstanding of actual experiments with photons as wave or particle-like due to not "really knowing" the math. That's hogwash and shows a major misunderstanding of the real-world nature of these experiments. The experiments are not about math. math may be used to describe the experiments and make predictions, but they are an actual, real-world process, and to suggest otherwise is a stupendous error.
Iblis was only saying that the Wiki article makes it easier to reach misunderstandings like yours. He's not saying the results of the experiments aren't real, which is what you mischaracterize him as saying, but that the conclusions you reach from reading descriptions of the experiments are incorrect and don't actually follow from the experimental results.
Let me return to a point I made earlier. Were your interpretation actually the correct one and it is just a group of us here at EvC Forum that have fallen into a misinterpretation but that the rest of the scientific world shares your interpretation, then you could walk into the science section of any large bookstore and find popularizations of quantum theory that include descriptions of how one day we might be able to retroactively change past events. But such books don't exist. That's because the scientists whose views such books attempt to represent don't think this is a valid interpretatin of quantum theory.
I do think that Iblis makes an error in his appendix example at the end of his message. It implies that the difference between the two particles actually existed back in time, we just didn't know which was which until later. I don't believe that's correct.
I like Wikipedia a lot, but I've found that one has to take care and not be too trusting. Much of it is fine, but for subtle or complex topics it is a good idea to find confirming sources. Anyway, about quantum entanglements Wikipedia includes this comment:
Wikipedia writes:
Although two entangled systems appear to interact across large spatial separations, no useful information can be transmitted in this way, so causality cannot be violated through entanglement.
It doesn't get any clearer than that.
--Percy

This message is a reply to:
 Message 43 by randman, posted 06-18-2006 12:19 AM randman has replied

Replies to this message:
 Message 78 by randman, posted 06-18-2006 2:35 PM Percy has replied

  
Jazzns
Member (Idle past 3912 days)
Posts: 2657
From: A Better America
Joined: 07-23-2004


Message 77 of 246 (322868)
06-18-2006 10:24 AM
Reply to: Message 40 by randman
06-17-2006 11:03 PM


Re: QM
No you just don't understand what I am talking about. If a point in the past is singularly determined then time is STILL linear. It is only not so if I could somehow continually determine a single point in time in which case the result would be many alternate timelines. If you can only determine it once, time is still linear.
Also you didn't address at all my point on how you would even tell if a point is time was determined or not.

Of course, biblical creationists are committed to belief in God's written Word, the Bible, which forbids bearing false witness; --AIG (lest they forget)

This message is a reply to:
 Message 40 by randman, posted 06-17-2006 11:03 PM randman has not replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 78 of 246 (322920)
06-18-2006 2:35 PM
Reply to: Message 76 by Percy
06-18-2006 10:06 AM


science fiction as an argument
Percy, your appeal to science fiction or stuff like that is strange on a several points. First off, it is factually wrong as there is fiction in both books and movies related to time travel and things like this. In fact, there is a ton of it.
Secondly, the issue of fiction has no place in a scientific discussion.
Third, you act as though transverse wave theory and the many-worlds theory don't exist. Transverse waves are causality backwards in time, but theorized in a manner to preserve the time-line on a macro-level. Many-worlds deals with an evolving multiverse continually being spun off (all possible realities coexist).
The more mainstream theories deal with photons in these experiments upon observation taking on more particle-like behaviour, and in fact experiments do demonstrate this with the photon's path prior to the observation affected. This is incontrovertible. You are just not understanding the experiments, though it appears PaulK did.
The simple fact is in the delayed-choice experiments, the delayed-choice is a delayed-observation/measurement. What it shows is that the photon acts as a particle, going through one hole or the other, rather than a wave, when it is observed, and this is amazingly true even if the particle goes through one path prior to the observation. That is why language is sometimes used as if the photon "knows" what is going to happen to it, and so knows to be particle-like.
There are a lot of theories to explain why this occurs, and no one is disputing that, but you and some others seem to be disputing that it even occurs at all, as if the experiments are not real or something, and imo, that is wrong.
There is a reason language is used to suggest the photon seems to know in advance, and the most logical assumption and the actual thing we observe (however you want to reinterpret it) is that a later event on the photon's trajectory affects it's path before it got there.
This is really what Wheeler's original thought experiment dealing with a photon from billions of years away was about. He theorized that the photon's path would be based on how we decide to observe it. Wheeler's solution to the issue was to claim the photon had never really travelled at all until we observe it, but existed in an undefined and unreal state of possibilities.
There are other ways to look at it, but these experiments were designed to test that idea, and they showed that indeed the way we observe, and even whether we have the ability to observe affects the photon's behaviour. If we can know it's path, it travels in one path only. If that information is scrambled and we cannot know it's path, it travels more wave-like in superposition. That can be seen with the interference pattern appearing when we have no way to know the path, and disappearing when we do have a way even if delayed to after the fact.
This is why Anton Zellinger theorizes that elementary particles as he calls them contain a bit of information. Once that information is able to be detected, then the collapse occurs and the bit is spent.
Imo, you don't seem to have a basic grasp of the discussion as evidenced by your comment on FTL communication which is an interesting debate, but not that germane to this particular discussion. You ought to take some time to look at these experiments. Read what Zellinger thinks is going on and some of his work. Read Wheeler's views. See what the Chaio group thinks (some curious comments by them), etc,...
Edited by randman, : No reason given.

This message is a reply to:
 Message 76 by Percy, posted 06-18-2006 10:06 AM Percy has replied

Replies to this message:
 Message 84 by Percy, posted 06-18-2006 3:40 PM randman has not replied
 Message 85 by Percy, posted 06-18-2006 3:40 PM randman has replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 79 of 246 (322923)
06-18-2006 2:41 PM
Reply to: Message 75 by cavediver
06-18-2006 9:50 AM


Re: Yes it's possible
So backwards in time waves "obery causality"?
Clearly, the future can affect the past in your view if you think transverse waves can flow back and affect earlier times. Seems like a reversal here from your earlier claims?
Now on the topic of the wave-function being a 4-D function, are you claiming that the wave function spans more than one moment in time in respect to it's surroundings?

This message is a reply to:
 Message 75 by cavediver, posted 06-18-2006 9:50 AM cavediver has replied

Replies to this message:
 Message 81 by cavediver, posted 06-18-2006 3:05 PM randman has replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 80 of 246 (322926)
06-18-2006 2:50 PM
Reply to: Message 72 by PaulK
06-18-2006 6:53 AM


Re: general reply to all
My point is that the past is not materially affected. At the macroscopic scale nothing noticable has changed at all.
How is the past not materially affected? If the past takes on discrete form as a result of present observation, then it is materially affected. I assume materially refers to material and not in the legal sense.
Now, it may well be true these affects are very small at any given point in time, but adding up all points in time since this works, the effects can add up. Remember that the macroscopic world consists of the quantum world.
There may be parts of the past that remain indeterminate but that does not entail that those parts of the past that have been determined could be changed.
Why not? You admit that some parts of the past are indeterminate, or are determined later by events in the present. So should we assume these changes cannot affect the past? Your logic makes no sense. Causing an indeterminate area to be determined is by definition a change.
They don't even try to measure the role of consciousness and there is no reason to suppose the results would be any different if the conscious choice were to be replaced by an unthinking mechanical choice.
So? How is that relevant at all to the fact that the delayed-choice still affects the wave function as if the choice was not delayed; that the photon still travels one route and does so before the choice?
I do not agree that the macroscopic past can be changed through QM.
Everyone is entitled to their faith, but that doesn't make it a correct scientific argument.

This message is a reply to:
 Message 72 by PaulK, posted 06-18-2006 6:53 AM PaulK has replied

Replies to this message:
 Message 82 by PaulK, posted 06-18-2006 3:12 PM randman has replied

  
cavediver
Member (Idle past 3644 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 81 of 246 (322930)
06-18-2006 3:05 PM
Reply to: Message 79 by randman
06-18-2006 2:41 PM


Re: Yes it's possible
Clearly, the future can affect the past in your view
Clearly not.
Seems like a reversal here from your earlier claims?
Look, let's get something straight here: you are so out of your depth it is just not funny. To explain this stuff to an interested student would take more time than I have right now. To explain this stuff to you, with you thinking you have it all pat, and us scientists haven't a clue, is just a none starter. You need to go get yourself a real textbook on quantum mechanics and start some studying of the basics. You are trying to engage me and argue with me about something in which you have no foundation.
Now on the topic of the wave-function being a 4-D function, are you claiming that the wave function spans more than one moment in time in respect to it's surroundings?
We live in a 4d universe. How could it not? We write Psi(x,y,z,t). As I said, you need to go right back to the beginning...

This message is a reply to:
 Message 79 by randman, posted 06-18-2006 2:41 PM randman has replied

Replies to this message:
 Message 87 by randman, posted 06-18-2006 4:16 PM cavediver has not replied

  
PaulK
Member
Posts: 17822
Joined: 01-10-2003
Member Rating: 2.2


Message 82 of 246 (322931)
06-18-2006 3:12 PM
Reply to: Message 80 by randman
06-18-2006 2:50 PM


Re: general reply to all
The past is not materially affected because the newly determined state is consistent with all past observations. Only future observations can potentially be affected.
quote:
There may be parts of the past that remain indeterminate but that does not entail that those parts of the past that have been determined could be changed.
Why not? You admit that some parts of the past are indeterminate, or are determined later by events in the present. So should we assume these changes cannot affect the past? Your logic makes no sense. Causing an indeterminate area to be determined is by definition a change.
It would be better for you to explain why it is entailed. However, if the only change possible is for an object in a superposition of states to be fixed in a single state then naturally objects that are already in a determined state will not be affected. As I have pointed out the only "changes" available to you leave past observations unaffected.
quote:
So? How is that relevant at al l to the fact that the delayed-choice still affects the wave function as if the choice was not delayed; that the photon still travels one route and does so before the choice?
As should be clear from the context my point is that the delayed choice experiments do not test for any role for consciousness. There is no reason to beleive that a "choice" contolled by a random number generator would produce any different result. Conscious choice as such may not play any significant role.
quote:
I do not agree that the macroscopic past can be changed through QM.
Everyone is entitled to their faith, but that doesn't make it a correct scientific argument.
And that works both ways. You have only faith that changes to the macroscopic past are possible through QM.
As I understand it, the science tends to support my position over yours, and with the philosophical and theological problems with your position brought out in my first message to this thread it's hard to see why you keep arguing. k
Edited by PaulK, : No reason given.

This message is a reply to:
 Message 80 by randman, posted 06-18-2006 2:50 PM randman has replied

Replies to this message:
 Message 83 by randman, posted 06-18-2006 3:33 PM PaulK has replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 83 of 246 (322933)
06-18-2006 3:33 PM
Reply to: Message 82 by PaulK
06-18-2006 3:12 PM


Re: general reply to all
The past is not materially affected because the newly determined state is consistent with all past observations.
Care to prove or substantiate that? That is your assumption, and that's the point here.
Moreover, this gets more complicated as "consistent with all past observations" is not really a well-defined concept, is it?
However, if the only change possible is for an object in a superposition of states to be fixed in a single state then naturally objects that are already in a determined state will not be affected.
The quantum eraser experiments have proven that "determined" states can be undone, despite physicists thinking otherwise for decades. A collapse of the wave function to particle-like path and behaviour can be reversed, correct?
So there are not determined states that cannot be changed. I have given a hard example backed by experiments where information can be erased, and so a determined path undone. Have you got anything to back up your claim that it cannot be?
Why not be openminded here and consider the possibility, or better yet, the likelihood that indeed the past is not determined, but can be affected, but those affects are small at any given point in time, but multiplied over all points in time, they add up.
As should be clear from the context my point is that the delayed choice experiments do not test for any role for consciousness. There is no reason to beleive that a "choice" contolled by a random number generator would produce any different result. Conscious choice as such may not play any significant role.
I think you and Percy as well are mixing up thread topics. I have talked about the role of consciousness on other threads, but it matters not a whit for the scope of this discussion, except perhaps if we get into the idea of the It from Bit. But whether it is a mechanical process (that can potentially be observed) or not, the issue is quite simply that the collapse of the wave function to a particle-like path occurs even when the measurement on the trajectory occurs afterwards.
Then the
famous question can be posed: through which of the two
slits did the particle actually pass on its way from source
to detector? The well-known answer according to standard
quantum physics is that such a question only makes
sense when the experiment is such that the path taken
can actually be determined for each particle. In other
words, the superposition of amplitudes in Eq. (1) is only
valid if there is no way to know, even in principle, which
path the particle took. It is important to realize that this
does not imply that an observer actually takes note of
what happens. It is sufficient to destroy the interference
pattern, if the path information is accessible in principle
from the experiment or even if it is dispersed in the
environment and beyond any technical possibility to be
recovered, but in principle still ””out there.’’ The absence
of any such information is the essential criterion for
quantum interference to appear. For a parallel discussion,
see the accompanying article by Mandel (1999) in
this volume.
http://www.physik.fu-berlin.de/...ikationen/RevModPhys99.pdf
Note that the criterion is whether information is available to know whether the particle took one path or the other. If this knowable based on the current events in the apparatus, the photon travels as a particle, but if not, as a wave.
The germane point to this discussion is that even if part of the apparatus that can indicate whether a wave or particle passes through is placed at the end of the process, the result is the same. The photon takes a particle path, and this confirms some aspects of Wheeler's delayed-choice thought experiments, right? That a present event can have a determinative affect on the past. The pathway of the photon BEFORE the measurement is affected if the measurement is such that information can be conveyed.
Note Zeilinger's comment on the mascroscopic world (same link).
In any case, it will be interesting in the future to see
more and more quantum experiments realized with increasingly
larger objects. Another very promising future
avenue of development is to realize entanglements of
increasing complexity, either by entangling more and
more systems with each other, or by entangling systems
with a larger number of degrees of freedom. Eventually,
all these developments will push the realm of quantum
physics well into the macroscopic world.
Edited by randman, : No reason given.

This message is a reply to:
 Message 82 by PaulK, posted 06-18-2006 3:12 PM PaulK has replied

Replies to this message:
 Message 86 by PaulK, posted 06-18-2006 4:13 PM randman has replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 84 of 246 (322935)
06-18-2006 3:40 PM
Reply to: Message 78 by randman
06-18-2006 2:35 PM


Re: science fiction as an argument
Duplicate content removed, website is somehow misbehaving today, very strange!
Edited by Percy, : Duplicate post.

This message is a reply to:
 Message 78 by randman, posted 06-18-2006 2:35 PM randman has not replied

  
Percy
Member
Posts: 22394
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 85 of 246 (322936)
06-18-2006 3:40 PM
Reply to: Message 78 by randman
06-18-2006 2:35 PM


Re: science fiction as an argument
randman writes:
Percy, your appeal to science fiction or stuff like that is strange on a several points. First off, it is factually wrong as there is fiction in both books and movies related to time travel and things like this. In fact, there is a ton of it.
Of course there is. My favorite is David Gerald's The Man Who Folded Himself.
But you've misunderstood the point, which was that if your view were the one actually shared by physicists, then science fiction writers would have picked up on it as a mechanism for time travel stories. I was trying to get you to see that isn't just at EvC Forum that no one agrees with you - no one agrees with you anywhere, not even science fiction writers.
The other part of the point was that if your view were correct, then you could walk into bookstores and find science popularizations talking about what scientists have discovered about the possibilities of changing the past. But you can't find such books. Because they don't exist. Because scientists don't believe the present can change the past.
Secondly, the issue of fiction has no place in a scientific discussion.
Then why are you here?
Seriously, I wasn't introducing fiction into the discussion. I was making the point that even those who stretch the views of science for a living haven't gone where you are going. It was just an attempt to get you to see just how far "out there" you are.
Transverse waves are causality backwards in time,...
Really? I didn't know that. I don't think anybody knows that there's causality backwards in time.
There are a lot of theories to explain why this occurs, and no one is disputing that, but you and some others seem to be disputing that it even occurs at all...
You keep saying stuff like this, and everyone keeps telling you that we all accept and understand entanglement, and we all accept and understand the 2-slit experiment. What we're telling you is that you are drawing incorrect conclusions from these experiments. These experiments are not demonstrations of backwards causality. Backwards causality is just your misinterpretation.
Imo, you don't seem to have a basic grasp of the discussion as evidenced by your comment on FTL communication which is an interesting debate...
Omigod! Don't tell me you also believe entanglement makes possible faster than light communication! That would be almost too funny! Look out, Alice and Bob, here we come!
--Percy

This message is a reply to:
 Message 78 by randman, posted 06-18-2006 2:35 PM randman has replied

Replies to this message:
 Message 91 by randman, posted 06-18-2006 4:49 PM Percy has not replied
 Message 93 by randman, posted 06-18-2006 4:51 PM Percy has not replied

  
PaulK
Member
Posts: 17822
Joined: 01-10-2003
Member Rating: 2.2


Message 86 of 246 (322939)
06-18-2006 4:13 PM
Reply to: Message 83 by randman
06-18-2006 3:33 PM


Re: general reply to all
quote:
The past is not materially affected because the newly determined state is consistent with all past observations.
Care to prove or substantiate that? That is your assumption, and that's the point here.
I'm only stating my position here, which is to my understanding consistent with QM. If you claim that it is wrong it is up to you to substantiate your position.
quote:
The quantum eraser experiments have proven that "determined" states can be undone, despite physicists thinking otherwise for decades. A collapse of the wave function to particle-like path and behaviour can be reversed, correct?
To the best of my understanding they do not affect the past in the way you suggest. In fact they work by erasing the influence of the past - according to the link you provide they render it impossible for past observations to be contradicted.
From your own link:
Obviously, the interference pattern can be obtained if
one applies a so-called quantum eraser which com-pletely
erases the path information carried by particle 2.
That is, one has to measure particle 2 in such a way that
it is not possible, even in principle, to know from the
measurement which path it took, a8 or b8.
This seems to support my view that past observations are not contradicted. If they could be then why would we need to erase the information that might produce a contradiction ?
quote:
Why not be openminded here and consider the possibility, or better yet, the likelihood that indeed the past is not determined, but can be affected, but those affects are small at any given point in time, but multiplied over all points in time, they add up.
I have already given reaons why your hypothesis is sterile. In the absence of significant arguments for it, why should I consider it any further than I have. Why can't you be openminded enough to admit that your idea is simply speculation and quite likely false ?
quote:
I think you and Percy as well are mixing up thread topics. I have talked about the role of consciousness on other threads, but it matters not a whit for the scope of this discussion
Since I was responding directly to one of your comments, made in this thread, and quoted in the earlier reply it seems unlikely that I am mixing up threads.
As to your long quote, lets get to the meat:
quote:
The pathway of the photon BEFORE the measurement is affected if the measurement is such that information can be conveyed.
And the way it is affected is that instead of being a superoposition of states it is one single state. That's it. In other words it presents absolutely no support for your idea.
I'm not sure how well supported Zeilinger's ideas on entanglement in macroscopic objects are. Certainly my own reading indicates that the idea that macroscopic changes automatically collapse the wave function was widely held.

This message is a reply to:
 Message 83 by randman, posted 06-18-2006 3:33 PM randman has replied

Replies to this message:
 Message 89 by randman, posted 06-18-2006 4:31 PM PaulK has replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 87 of 246 (322940)
06-18-2006 4:16 PM
Reply to: Message 81 by cavediver
06-18-2006 3:05 PM


Re: Yes it's possible
cavediver, so we are back to your typical approach, eh? Resort to claims of authority and refuse to substantiate your points, substituting your resume for argument.
The problem is that you suggest all scientists agree with you here when clearly that is not the case. You also dodged the issue of whether in your view a 4-D wave-function operates over several points of time simultaneously. If that is your stance, I can see why you don't want to go there. You would then by definition be agreeing with me.
On having all this down-pat, no, I don't claim that. At the same time, the little bit I have gleaned is pretty straightforward although understanding the correct interpretation is dicey. You though, seem to be denying the actual events observed in experiments, and do so in a rude manner without ever getting into the details, and just say, you don't understand it, but each time I question you about details, you are forced to admit those details.
Maybe you just don't like the implications of these experiments. Einstein didn't like some of the implications either, whether true ot not, but not liking the implications due to your theology is not the same as a scientific argument.
If we can know about which path the photon took in the experiments, then it behaves like a particle, correct?
If we cannot know, then it behaves like a wave, correct?
This is true even if the way we can know which path it takes occurs after the path has been taken, correct?
So however you want to describe it, the simple fact is from our vantage point, the event to determine what we can know even when occuring after the photon travels, results in the same thing; particle-like behaviour.
I realize you may have all sorts of ways to talk about this, as do many physicists; some like Wheeler resolve it by stating the photon doesn't really exist as a wave or particle until observed or measured, but regardless, the path BEFORE THE MEASUREMENT in it's trajectory is affected somehow.
Btw, for the lurkers, one of the solutions often presented (by men such as Wheeler) and often rejected by others is as follows:
The key notion here may be that one "has to take into account the whole experimental apparatus" and that that INCLUDES the experimenter. Its not either that "how reality is seen depends on how we measure it" OR that "reality changes depending on how we measure it" but rather that one needs probably to drop the concept of "reality" as distinct from the experimenter altogether.
410 error - Gone
Note the way some, and perhaps PaulK on this thread is one, gets around the appearance of "reality changes depending on how we measure it" is to deny reality altogether as separate from the observer and other factors. My point is that this is a conundrum because the experiments appear to show delayed-choice affecting past reality, and in one sense, there is no question that occurs. The question is whether we have a good enough handle on what reality and the past actually consists of, imo.

This message is a reply to:
 Message 81 by cavediver, posted 06-18-2006 3:05 PM cavediver has not replied

  
Iblis
Member (Idle past 3896 days)
Posts: 663
Joined: 11-17-2005


Message 88 of 246 (322943)
06-18-2006 4:25 PM


the emperor has no shoes
One small part of the problem is that the word "entanglement" is being used 2 different ways in the array of sources being appealed to. I'm going to try to get around this by using capital-E Entanglement in reference to the new theory that is gently replacing Heisenberg's Uncertainty Principle and lowercase-e entanglement in reference to the phenomenon which is covered by both, but which the experiments are showing is covered best by the new, in that the results seem to reduce the old to nonsense.
IF and only if Heisenberg were a complete picture of the phenomenon of entanglement, these experiments could be said to break causality and send information backwards in time. Seeing as how this is manifest nonsense, for the simple reason that we couldn't catch it happening if that was the case, and whatever is happening is in fact observable, the Uncertainty Principle is being supplemented / replaced by what is presently being referred to as Entanglement theory in honor of the phenonomenon that is doing the work of breaking the old paradigm.
Percy writes:
Iblis makes an error in his appendix example
Yep, that's me carefully selecting which inanities I'm willing to be reduced to in order to cover a specific point. A more accurate analogy would be one guy who can somehow be in two places at once, who is mistakenly believed to be twins, and doctors who are surprised that when one "twin" has his appendix out, the appendix of the "other twin" also seems to have disappeared. (An even more accurate analogy would be if the "twins" or manifestations of the single person were too small to see, too fast to see, seemed to appear and disappear at will, and had to be operated on with scalpels that were already cutting away at them while the operating table was still empty.)
Here's the main deal though. The mistaken, bad, wrong assumption playing out here is that entanglement involves two separate entities, thought of as classical particles, which retain a specific causal relationship due to some prior relationship. The reality is that they are not separate entities at all, they are different ends of the same waveform.
cavediver writes:
elucidate?
I'm just saying, if I ever have to teach a class, I'm going to call on the guy who has his shoes on backwards, because it appears to be more educational for the general audience when we correct answers that are dead wrong than when we try to improve on someone who mostly has it right already

Replies to this message:
 Message 90 by randman, posted 06-18-2006 4:38 PM Iblis has replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 89 of 246 (322945)
06-18-2006 4:31 PM
Reply to: Message 86 by PaulK
06-18-2006 4:13 PM


Re: general reply to all
I'm only stating my position here
That's correct. You are stating your position (an assumption) without any substantiation.
This seems to support my view that past observations are not contradicted. If they could be then why would we need to erase the information that might produce a contradiction ?
The experiment has nothing to do with "erasing information that might produce a contradiction" as far as I can tell. The experiment is about a simple observation that overturned previous beliefs. If the potential to know the path is there, the photon takes on path, but that information can be erased by removing the ability to determine what path the photon took. If we cannot know what path the photon took, then the photon takes all the available paths.
That's what the experiment is showing. It doesn't explain this coorelation between potential knowledge and the wave-function, but it does demonstrate it. Zeilinger offers a theory to explain it, however.
But regardless, I don't see where you come up with the past observations thing.
And the way it is affected is that instead of being a superoposition of states it is one single state. That's it. In other words it presents absolutely no support for your idea.
How is that not hard evidence of what I am talking about, PaulK. There is clearly a definite change in what the photon does, behaving more like a particle or more like a wave. It is affected, right?
I'm not sure how well supported Zeilinger's ideas on entanglement in macroscopic objects are. Certainly my own reading indicates that the idea that macroscopic changes automatically collapse the wave function was widely held.
As was the idea that the quantum eraser was totally impossible, but we see that was not the case, don't we?

This message is a reply to:
 Message 86 by PaulK, posted 06-18-2006 4:13 PM PaulK has replied

Replies to this message:
 Message 92 by PaulK, posted 06-18-2006 4:49 PM randman has replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 90 of 246 (322949)
06-18-2006 4:38 PM
Reply to: Message 88 by Iblis
06-18-2006 4:25 PM


whose mistaken assumption
The mistaken, bad, wrong assumption playing out here is that entanglement involves two separate entities, thought of as classical particles, which retain a specific causal relationship due to some prior relationship. The reality is that they are not separate entities at all, they are different ends of the same waveform.
Whose mistaken assumption are you talking about? Certainly not mine. In fact, you coming around to this point (from my vantage point) helps bring my point home. Here we have a system that manifests 2 or more discrete forms in the material universe over long distances and considering GR, irrespective of time, correct?
So the waveform occupies and works in a manner irrespective of space and time in some sense, correct?
Now here is the crux of this debate....if we conduct an action at the end of a photon's path that can determine which path the photon took, does it act particle-like and take one path or does it behave like a wave and take all potential paths?
I submit that the photon takes on path like a particle, and as such, the action at the end of it's path affects which path the particle took before it ever got to the end of it's path. I further submit that this is not randman's idea but a simple, observed fact for which some reason you guys don't want to come clean and admit to.
Now, I realize there are lots of different interpretations, but I think there needs to be some agreement that the photon behaves like a particle and takes on path if that is knowable, even if the way to determine which path it took occurs at the end of the process and after the path has occured.
Edited by randman, : No reason given.

This message is a reply to:
 Message 88 by Iblis, posted 06-18-2006 4:25 PM Iblis has replied

Replies to this message:
 Message 96 by Iblis, posted 06-18-2006 5:18 PM randman has replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024