Interaction is Everything


    1 Comment

  1. Daniel PinkelNovember 18th, 2018 at 07:40 pm

    The conclusions of this paper rely critically on the interpretation of the Quantum Maze experiment in Figure 7.  The author has focused on the entanglement between the two photons that could be generated in each of the down converters, and further asserts that the status of detectors monitoring the idler channels (“on” or “off”) determine whether or not an interference pattern will appear on the screen.

    By contrast I do not believe that an interference pattern will be produced under any conditions if the experiment behaves as the author indicates.  The basic reason is that under the authors assumptions each signal photon that is detected on the screen will originate entirely in one or the other of the down converters.  The pattern produced on the screen will be the overlapping single slitpatterns produced by each of the down converters acting individually.  There is no interference.  Note that in a classic double slit experiment each detected signal photon has its origin in both slits.   Since there is never a diffraction pattern in this analysis, none of the issues that concern the author about positioning of the idler detectors, and space and time should arise.

    I suggest that a more complete analysis of this experiment would find that there is a (partial) diffraction pattern, but also that there would be no issues of space and time that the author is concerned with.  Consider the following:

    For each input photon there are two output photons from the down converters, each with half the initial energy. While the author focuses on both photons coming from one or the other of the down converters, I believe that the overall entanglement in this system also allows for the output photons to come from different down converters.  Thus if one placed detectors directly at the 4 output channels of the down converters one would detect two output photons for each input photon, and those would be distributed randomly over all possible pairs of the output detectors.

    If we then arrange for any two of the output channels overlap on the screen in Figure 7, which are then called the signal channels, we can ask what intensity pattern will develop after inputting multiple single photons.  This intensity pattern has three contributions:

    1. If no photons are detected on the screen for an input photon, then for that trial an output photon will appear in both idler channels. These are available for detection by the idler detectors, but this behavior does not depend on whether idler detectors exist or are turned on. Events of this type will occur for on average 1/6 of the input photons.

    2. If one photon is detected on the screen for an input photon, then one photon would also appear in one or the other of the idler channels. These could be detected by idler detectors (if they exist and are turned on), but they could provide no definitive “which way” information.  Whether or not these detectors exist and are turned on makes no difference to the outcome.  Similar to the discussion at the beginning of my comments, these signal photons would be distributed on the screen in a single slit pattern since each signal photon has its source entirely in one of the down converters, even though it was not possible to determine which down convertor produced it. The lack of “which way” information may be necessary to produce diffraction, but it is not sufficient. This type of event will occur on average for 4/6 of the input photons.

    3. If two photons are detected at the screen for one input photon, then no photons will appear in the idler channels.Both of these signal photons have their (coherent) origins in both down converters, and thus these double-detection events will form a two slit diffraction pattern on the screen.  Events of this type will occur for on average 1/6 of the input photons.

    Combining these expectations, the overall signal pattern on the screen will consist of a diffraction pattern riding on top of a single-slit pattern.  The single slit pattern will contain 2/3 of the photons detected at the screen (4/6*1), while the diffraction pattern will contain 1/3 of the photons detected at the screen (1/6*2).  Given the fact that the signals from the interference pattern are restricted to about half of the area (in the peaks), the troughs of the overall pattern will have about 50% of the intensity of the peaks.

    If the above analysis of the experiment is correct, then neither the existence, nor the location, nor the “on/off” status of the idler detectors affects the signal pattern on the screen.

    If the author disagrees with these comments I suggest that he provide a reference to, or present, a full analysis of the complex entanglement relationships and their consequences.

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This paper argues that experimental evidence, quantum theory, and relativity theory, taken together, suggest that reality is relational: Properties and behaviors of phenomena do not have a priori, intrinsic values; instead, these properties and behaviors emerge through interactions with other systems.


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Joshua Sandeman (2018). Interaction is Everything. Researchers.One,

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