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Paul WV

Beckley, WV

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#323
Mar 18, 2012
 

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polymath257 wrote:
<quoted text>
No, you are misunderstanding these experiments. The well confirmed experimental fact is that QM is upheld in every case. Instead of the electron being 'in both boxes', the probability wave is. The electrons are only detected at the *end* of the experiment, when the wave has had a chance to interfer (or not).
<quoted text>
No, you are misunderstanding what happens in these experiments. Let me focus on a specific example: the quantum 'bomb detector':
http://en.wikipedia.org/wiki/Elitzur%E2%80%93...
In this experiment, a photon is passed through a half-silvered mirror, which allows the photon to go one of two paths: either by a bomb or a different path that avoids the bomb. If the bomb is a 'dud', a photon taking the path by the bomb will not be absorbed, while if the bomb is 'usable', the photon will certainly be absorbed and the bomb will explode. If the photon takes the path away from the bomb, the bomb does not explode in either case.
After, the two paths are brought back together, allowing interference to happen. There are two detectors: A and B. The experiment is adjusted so that interference from the two paths is complete, sending a signal to A and not to B. If only one path is taken, both A and B fire with equal probability. Such a setup can be done in practice.
What happens? Classically, there is no way of knowing there is a usable bomb without it exploding: the path around the bomb gives no information, but the path by the bomb will make the bomb explode. There is no way to determine a bomb is usable and NOT to explode it.
Quantum mechanically, the *probability wave* starts going through *both* paths no matter what. If there is a dud, both paths are fully taken, there is complete interference, and only detector A fires. But if there is a usable bomb, the part of the probability wave going past the bomb is blocked, so no interference happens. In that case, A fires half the time and B fires half the time. But now, if B fires, we *know* the bomb is usable even though it did not explode! We end up detecting half of the usable bombs.
This experiment (obviously not with bombs) has been done and the results agree with quantum mechanics.
This shows the 'reality' of the probability wave even if the photon 'does not go past the bomb'. In reality, the probability wave goes through both paths and either interfers or does not depending on whether there is a bomb. This happens even if only one photon is 'in the aparatus' at a time.
Notice that it is NOT consciousness that determines the results here.
If you have another, specific, experiment that you think shows the electron (or photon) is 'actually' in two places at a time as opposed to the probability wave being so, please give a link.
The probability wave is the electron's probability wave and it is both places. You are very inconsistent in your thinking; at one point you agreed with the article I linked which says the probability waves are real and this gives rise to the many-world hypotheses. Now you are talking like the probability wave is not real but some phantom, mathematical abstract, or spirit. So, is the probability wave real or not? Whether the wavefunction is real or not the electron is said to be in two places until it is observed; a position held by leading physicists.

“Think&Care”

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#324
Mar 18, 2012
 
Paul WV wrote:
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The experiments "demonstrate" the electron is either in both boxes
In these experiments, the electron is *never* detected in both boxes. Instead, the wave function goes through both boxes and then interfers. The fact that there is interference says the wave function was in both boxes. But the elcrons are only detected *after* the interferenc, never in the boxxes themselves.
or one box
In these experiments, the wave function is either not allowed to interfer. That changes the resuoting wave function. Also, in *this* case, the electrons are typically atually measured in the boxes and are found in one or the other. Again, the probability wave *at the detector* determins the probability of detecting an electron in *all* cases.
depending on which experiment you "chose" to do. It is the observerís choice of experiments which determines whether the electron is in both boxes or only one box.
No, it is the experimenter's choice whether the wave function goes through both boxes and interfers or is detected in the boxes themselves.

“Think&Care”

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#325
Mar 18, 2012
 
Paul WV wrote:
<quoted text>
The probability wave is the electron's probability wave and it is both places. You are very inconsistent in your thinking; at one point you agreed with the article I linked which says the probability waves are real and this gives rise to the many-world hypotheses. Now you are talking like the probability wave is not real but some phantom, mathematical abstract, or spirit. So, is the probability wave real or not? Whether the wavefunction is real or not the electron is said to be in two places until it is observed; a position held by leading physicists.
The probability wave is real. When have I said anyrhing different? It determins the probabiliy of detecting an electron at a detectr. It is sloppy use of language to say that the electron is on both places: no measurement detects an elecron in both places. What *is* detected in the interference of the probabiliy wave.

“Think&Care”

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#326
Mar 18, 2012
 
Paul WV wrote:
<quoted text>
The probability wave is the electron's probability wave and it is both places. You are very inconsistent in your thinking; at one point you agreed with the article I linked which says the probability waves are real and this gives rise to the many-world hypotheses. Now you are talking like the probability wave is not real but some phantom, mathematical abstract, or spirit. So, is the probability wave real or not? Whether the wavefunction is real or not the electron is said to be in two places until it is observed; a position held by leading physicists.
Peraps I should clarify what happens in he bomb detector.

Le's assume, for the sake of specificiy, that 20% of bombs are usable.

Clasically, 50% of the photons go the path away from the bomb. half of these set off detector A and half set off detector B. The other 50% of the photons go past the bomb. Now, 20% of thiese will have a usable bomb, which will explode leaving nothing at the detector The other 80% will have duds, and the photon will trigger A half the time and B half the time.

The result: clasically,, 25+30=45% of the time, A will be triggered. Similarly, 45% of the time, B will trigger. In both cases, there will be no explosion. Finally, 10% of the time (half of 30%) the bomb will explode and no detector will be triggered.

In QM, A will *always* be triggered when there is a dud (80% of the time). If there is a usable bomb, there is no constructive interference so A will trigger half the time, and B half the time. So A triggers 90% of the time and B triggers 10%. Whenver B triggers, there is a usable bomb that did not explode. Of the 90% of the time that A triggers, 10% will also have an explosion from a bomb.

“Think&Care”

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#327
Mar 19, 2012
 
Where there are 30's, read 20's above.
Paul WV

United States

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#328
Mar 19, 2012
 
polymath257 wrote:
<quoted text>
The probability wave is real. When have I said anyrhing different? It determins the probabiliy of detecting an electron at a detectr. It is sloppy use of language to say that the electron is on both places: no measurement detects an elecron in both places. What *is* detected in the interference of the probabiliy wave.
So are you not in agreement with the Copenhagen Interpretation which holds the wave function is not real?

“Think&Care”

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#329
Mar 19, 2012
 
Paul WV wrote:
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So are you not in agreement with the Copenhagen Interpretation which holds the wave function is not real?
The Copenhagen Interpretation holds that to talk about *anything* other than measured results should be avoided. So, an electron is not 'real' in the Copenhagen Interpretation until and unless it is measured. I do not go so far.

So, once again, the wave function is as real as *anything* at the quantum level. In the way that I use the term 'real', both electrons and wave functions are real. My definition differs from that of the Copenhagen interpretation in that I allow things to be real even if not directly measured as long as they have measurable effects. At this point, it is a matter of semantics, which is why I asked you for *your* definition of the term 'real'.
Paul WV

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#330
Mar 19, 2012
 
polymath257 wrote:
<quoted text>
The Copenhagen Interpretation holds that to talk about *anything* other than measured results should be avoided. So, an electron is not 'real' in the Copenhagen Interpretation until and unless it is measured. I do not go so far.
So, once again, the wave function is as real as *anything* at the quantum level. In the way that I use the term 'real', both electrons and wave functions are real. My definition differs from that of the Copenhagen interpretation in that I allow things to be real even if not directly measured as long as they have measurable effects. At this point, it is a matter of semantics, which is why I asked you for *your* definition of the term 'real'.
I would use real in the same sense the Copenhagen Interpretation does.

“Think&Care”

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#331
Mar 19, 2012
 
Paul WV wrote:
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I would use real in the same sense the Copenhagen Interpretation does.
So then an electron isn't real unless it is being measured? In which case the electron *isn't* in both boxes since it is meaningless to say where it is at all unless there is a specific measurement for its position. That is consistent, but leads to the question of how so many un-real things can produce something real like a chair.
Paul WV

Beckley, WV

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#332
Mar 19, 2012
 
polymath257 wrote:
<quoted text>
So then an electron isn't real unless it is being measured? In which case the electron *isn't* in both boxes since it is meaningless to say where it is at all unless there is a specific measurement for its position. That is consistent, but leads to the question of how so many un-real things can produce something real like a chair.
So you "are" saying the electron is in two places until it is observed.

“Think&Care”

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#333
Mar 19, 2012
 
Paul WV wrote:
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So you "are" saying the electron is in two places until it is observed.
No. I am saying that it has no definite position: it only has probabilities of being in various positions. These probabilities are given by the wave function.

“Think&Care”

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#334
Mar 19, 2012
 
Paul WV wrote:
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So you "are" saying the electron is in two places until it is observed.
*YOU* are the one that claimed it was in both boxes, not me. The wave function is in both boxes and there is a probability for the electron to be in both boxes, but the position is not determined.
Paul WV

Beckley, WV

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#335
Mar 19, 2012
 
polymath257 wrote:
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*YOU* are the one that claimed it was in both boxes, not me. The wave function is in both boxes and there is a probability for the electron to be in both boxes, but the position is not determined.
Now that we agree the wave function is "real" we can throw out the Copenhagen Interpretation and go from there. Now you lean towards the many-world hypotheses and I lean more towards a conscious observer creates reality hypotheses. Where there is experimental evidence giving my position an edge over your position there is none for yours.

“Think&Care”

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#336
Mar 20, 2012
 
Paul WV wrote:
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Now that we agree the wave function is "real" we can throw out the Copenhagen Interpretation and go from there. Now you lean towards the many-world hypotheses and I lean more towards a conscious observer creates reality hypotheses. Where there is experimental evidence giving my position an edge over your position there is none for yours.
I gave an example above with the bomb detector. Consciousness has nothing to do with the end results; only the presence of something interacting with the probability wave. Also, all the work on quantum coherence, which is used in making quantum computers (such as we have so far). Again, consciousness is not the determining variable, but interaction with a complex enough environment (in a way that the interaction can't be 'undone').

“Think&Care”

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#337
Mar 20, 2012
 
Paul WV wrote:
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Now that we agree the wave function is "real" we can throw out the Copenhagen Interpretation and go from there. Now you lean towards the many-world hypotheses and I lean more towards a conscious observer creates reality hypotheses. Where there is experimental evidence giving my position an edge over your position there is none for yours.
Care to give the experimental evidence for your position? Be specific.

“Quantum Junctn: Use Both Lanes”

Since: Dec 06

Tulsa, Oklahoma USofA

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#338
Mar 25, 2012
 
.... cricket... cricket....

... the silence from the godbot crowd is deafening.

“Universal Conscious Conscience”

Since: Feb 08

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#339
May 17, 2013
 
SupaAFC wrote:
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Congratulations?
Hey what have you been up to?

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