Discuss ultimate truth of universe between me & John Cramer. 争取以后造个时间机器的。。。。
-----Original Message-----
From: John G. Cramer [mailto:jcramer@u.washington.edu]
Subject: Re: My system to test retrocausality
Dear ,
The setup involves single photons, not entangled pairs. That would be a very big advantage, because making entangled pairs of photons is a tricky and very low-efficiency process. However, in my opinion there will be no superluminal "signal" provided by this setup.
Reason: whether the upstream splitter is in or out, one of detectors B and C will always detect a photon, so it is no different from placing a single detector immediately after the second splitter on the same path. With the upper splitter removed, one gets information about the path in the upper MZ interferometer but NOT in the lower MZ interferometer (which is what would be needed to suppress interference and put 50% of the photons into detector A). Therefore, with upper splitter IN, all photons (in a perfectly aligned MZ interferometer) would go to detector B. With upper splitter OUT, half the photons would go to detector B and the other half would go to detector C. In no case would any photons go to detector A, because the interference condition would still be present. Sorry!
Regards,
John Cramer
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> Mr. Cramer:
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> I am sending this for your review when you are convenient.
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> The following system will be able to test if the current measurement
> create or change a past event or not. The system involves two
> Mach-Zender interferometers. The second interferometer has a removable
> beamsplitter at last. The Detector A shall not detect any photon due
> the interference of the photons. However, if the removable
> beamsplitter is removed after the light has passed the last
> beamsplitter of the first interferometer, there shall be 50% of the
> times that Detector A will now detect the photon; because once the
> removable beamsplitter is removed, the photon must choose to take a
> path as a particle from the original light source, and the
> interference pattern will disappear at the first interferometer and
> the photon will have 50% chance to arrive at the Detector A. Exact
> time stamp shall be recorded whenever the detector A detects the
> photon at the above situation. It is expected the exact time stamp of
> the Detector A shall be slightly earlier than the exact time stamp
> when the removable beamsplitter is removed. If the time difference
> between when the removable beamsplitter is removed and when the
> Detector A detects the photon matches with the time required for light
> travel between the two interferometer systems with high accuracy, and
> if the probability of the Dectector A detects the photon in the
> beamsplitter-removed-situation is close to 50%, this will prove the
> validity of retrocausality of the quantum mechanics.
>
>
>
> See attached setup
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-----Original Message-----
From: John G. Cramer [mailto:jcramer@u.washington.edu]
Subject: Re: My system to test retrocausality
Dear ,
The setup involves single photons, not entangled pairs. That would be a very big advantage, because making entangled pairs of photons is a tricky and very low-efficiency process. However, in my opinion there will be no superluminal "signal" provided by this setup.
Reason: whether the upstream splitter is in or out, one of detectors B and C will always detect a photon, so it is no different from placing a single detector immediately after the second splitter on the same path. With the upper splitter removed, one gets information about the path in the upper MZ interferometer but NOT in the lower MZ interferometer (which is what would be needed to suppress interference and put 50% of the photons into detector A). Therefore, with upper splitter IN, all photons (in a perfectly aligned MZ interferometer) would go to detector B. With upper splitter OUT, half the photons would go to detector B and the other half would go to detector C. In no case would any photons go to detector A, because the interference condition would still be present. Sorry!
Regards,
John Cramer
>
> Mr. Cramer:
>
>
>
> I am sending this for your review when you are convenient.
>
>
>
>
>
>
> The following system will be able to test if the current measurement
> create or change a past event or not. The system involves two
> Mach-Zender interferometers. The second interferometer has a removable
> beamsplitter at last. The Detector A shall not detect any photon due
> the interference of the photons. However, if the removable
> beamsplitter is removed after the light has passed the last
> beamsplitter of the first interferometer, there shall be 50% of the
> times that Detector A will now detect the photon; because once the
> removable beamsplitter is removed, the photon must choose to take a
> path as a particle from the original light source, and the
> interference pattern will disappear at the first interferometer and
> the photon will have 50% chance to arrive at the Detector A. Exact
> time stamp shall be recorded whenever the detector A detects the
> photon at the above situation. It is expected the exact time stamp of
> the Detector A shall be slightly earlier than the exact time stamp
> when the removable beamsplitter is removed. If the time difference
> between when the removable beamsplitter is removed and when the
> Detector A detects the photon matches with the time required for light
> travel between the two interferometer systems with high accuracy, and
> if the probability of the Dectector A detects the photon in the
> beamsplitter-removed-situation is close to 50%, this will prove the
> validity of retrocausality of the quantum mechanics.
>
>
>
> See attached setup
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
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