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B Double Slit

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  1. Aug 4, 2015 #1
    I was wondering if the double slit experiment had been conducted in space away from interference from earths magnetic core/field. I know the scientific community would have considered all variables and would have set proper controls for this experiment but I am unable to find any notes on this. I am trying to figure out the magnetic/electrical field and gravity into this whole equation.

    -Geronimo
     
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  3. Aug 4, 2015 #2

    Orodruin

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    Earth's magnetic field is far too small (and homogenous on the scale of a typical double slit experiment) to affect the double slit experiment significantly. Furthermore, you can perform the double slit experiment with photons, which do not have a coupling to the magnetic field.
     
  4. Aug 4, 2015 #3
    Would you know what effect, if any, would gravity and solar winds have? I'll have to do the math on this one.

    Thank you,

    Geronimo
     
  5. Aug 4, 2015 #4

    Nugatory

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    Every piece of electronic equipment in any modern satellite or space probe depends on quantum mechanics working the way we expect in the presence or absence of the earth's magnetic field. That's a lot of testing of the basic principles.
     
  6. Aug 4, 2015 #5

    DrChinese

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    Yes, you get an interference pattern in a vacuum. In quantum versions of the double slit, the interference is always self-interference. Therefore the presence of air does not increase the interference effect.
     
  7. Aug 9, 2015 #6
    The same question occurred to me today and I was also unable to find any references for the 2 slits experiment having being carried out away from the influence of these fields. It would be fascinating to test for any variation in the results of the experiment were it to be carried out on the space station (perhaps this is not a practical option?). However Nugatory makes a good point to cast doubt on there being any variations when he says "Every piece of electronic equipment in any modern satellite or space probe depends on quantum mechanics working the way we expect in the presence or absence of the earth's magnetic field".

    From my understanding wherever the experiment was conducted there would always be some field present (e.g. background radiation) which could potentially be a factor in the presence of interference patterns. One difficulty with considering the potential effect of the presence electromagnetic waves on an atom or molecule seems to me to be in first comprehending what constitutes the wave (i.e. what is actually waving?).
     
    Last edited: Aug 9, 2015
  8. Aug 9, 2015 #7

    DrChinese

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    Do you have a hypothesis as to how "background radiation" would affect the outcome of a double slit experiment? Because nothing from current theory would apply. And the experiment controls for that anyway, by removing the presence or absence of "background radiation" as a variable.

    If you have a hypothesis, that could be separately tested - even on Earth perhaps. If you have no hypothesis, then this is purely speculation. You may as well ask if the results on Thursdays in Manila might be different than Tuesdays in Canada. I don't think that has been done either. Hopefully my point is clear.
     
  9. Aug 9, 2015 #8
    I almost missed where you were going, and was going to say gravity is negligible, and it should be commonly known what effect solar flares have on electrical systems, so I ask you to elaborate and confirm my suspicion, if you wouldn't mind.
     
  10. Aug 9, 2015 #9

    Vanadium 50

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    Why? The gravity on the space station is almost the same as it is on Earth.
     
  11. Aug 9, 2015 #10
    it is apparently about 89% of the effect on the surface of the earth so there is enough difference to potentially alter the results of an experiment.
     
  12. Aug 9, 2015 #11
    How does the experiment remove the presence or absence of "background radiation" as a variable?
     
  13. Aug 10, 2015 #12

    DrChinese

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    Because it is present when there is an interference pattern, and it is present when there is no interference pattern. The purpose of the double slit experiment is to demonstrate there is particle interference when the path is unknown/unknowable. So obviously the demonstrated effect is independent of "background radiation".

    On the other hand: if you had a hypothesis that "background radiation" could alter this experiment somehow, it would not be enough to change the standard predictions. But it might be detectable in a range of experiments that were designed to detect it.

    But you would need to have a hypothesis. What is yours? And is this simply conjecture, or do you have a particular reason to associate it with the double slit experiment in particular?
     
  14. Aug 11, 2015 #13
    Thank you for this explanation. I do not currently have any coherent hypothesis.

    What would preclude the individual atom during its journey through the slits from actually consisting of both a particle and a wave?
     
  15. Aug 11, 2015 #14

    DrChinese

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    Nothing in particular. This is something of a philosophical question, as there are interpretations (Bohmian Mechanics for example) in which there is both a point particle and something called a pilot wave. There is no known experiment (on Earth or otherwise) however which would identify this concretely, and it is actually axiomatic that there cannot be such (that doesn't stop folks from trying however).
     
  16. Aug 12, 2015 #15
    The background fields are not the only problem. When the experimenters put a sensor at one of the slits, the interference pattern disappears. The sensor must have an effect on the wave/particles going through the slit. How can they do that without invalidating the test. Also the particles that go close to the sides of the slit would be influenced by the Casmir effect. I am looking for a intuitive interpretation of the double slit experiment that takes into account these fields, sensors, and Casmir issues.
     
  17. Aug 12, 2015 #16
    The magnetic and gravitational fields are all very well understood besides the double slit, the only near miss is gravitational collapse, but that is way off topic for a standard double-slit interference pattern, which is simply intended to display destructive and constructive interference. Sensing the path the quantum objects take, as you mentioned has not just a lack of interference, but the introduction of "particle behavior" as well. The Casimir effect would just scatter the edges.
     
  18. Aug 12, 2015 #17

    DrChinese

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    Actually you can have the same "sensors" on both slits and get interference, or not get interference. So no, it's not the presence of sensors that do it. You should review the double slit fundamentals so you understand why this and the other things you mentioned are not factors. If they are held constant, they do not explain the results.
     
  19. Aug 12, 2015 #18

    Nugatory

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    Of course the detector has an effect - it makes the interference pattern disappear. That doesn't "invalidate" the test, it confirms the quantum mechanical prediction that there will be no interference pattern if there is a macroscopically significant interaction at either slit.
     
  20. Aug 13, 2015 #19

    Gaz

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    I hear a lot about detector's interfering with the pattern but no explanation ever telling me what detector's there actually using that causes it. Other than polarization filters what detectors are used ??
     
  21. Aug 13, 2015 #20
    Let me sum things up: Conventional wisdom: if there is a "macroscopically significant interaction at either slit" the wave collapses down to a particle which appears to go through only one or the other slit and the interference pattern disappears. I have no trouble with the wave itself anymore because particles cannot be made of still finer particles indefinitely. I used to find the wave-collapse concept as very mysterious but now I see it more intuitively: Any attempt to measure a wave must steal energy from it, and at the quantum level that might easily be half or all of the energy, so it disrupts the wave. It flips the attribute bits in a probabilistic way (based on probability, but perhaps jittered by real world chaos rather than true randomness).
     
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