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Silicon droplets and double slit, in 3D?

  1. Jul 14, 2014 #1
    So Yves Couder have these silicon droplets bouncing on a vibrating surface of some liquid:

    ...and apparently they can produce some things quantum particles do, like double slit fringe pattern trick. The question is how does that translate to 3D and would it still work? I mean, instead of bouncing on the surface droplets are submerged, but instead of transverse, the waves would be longitudinal, I guess, so would the double-slit trick still work?

    And also, would it be possible to achieve the same effect if instead of vibrating surface and droplets we use some kind of vibrating little balls, so they produce the waves themselves?
    Last edited by a moderator: Sep 25, 2014
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  3. Jul 14, 2014 #2

    Simon Bridge

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    The bouncing droplets exhibits some behavior which is similar to quantum effects but not exactly the same.
    The historical (3D) model that echoes this approach is called "pilot waves" or "deBroglie Bohm" and you can look it up under those terms.

    further reading:


    I don't think there can be a similar macroscopic experiment in 3D ... the water-surface bounce effects seem to rely on the "ball" spending most of it's time out of contact with the waves it produces. Totally immersed, that would not be possible.
  4. Jul 15, 2014 #3
    I don't quite see what "pilot wave" is really supposed to be in any practical terms, it's even more abstract than em-waves. Photons we can at least polarize and figure out there is really some waving going on and it has its plane of oscillation, frequency and wavelength. How do you measure a 'pilot wave'? In contrast to silicon droplets I don't think it's clear where or how exactly these pilot waves originate, and are they transverse or longitudinal. On the other hand, it sure makes more sense than a photon splitting apart to be in two places at once and then interacting with itself.

    I agree translation to 3D does not really seem to follow, but I also think there could be more to it, not immediately obvious. Can there exist transverse waves in "submerged" fluid dynamics?
  5. Jul 15, 2014 #4

    Simon Bridge

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    The pilot wave is pretty much as abstract as the probability waves - yeah.
    The attraction seems to be mostly due to being easier to imagine - but the maths is usually harder.
    Also - when the theory was originally mooted, some people were still hanging on to the notion that there is a medium to "empty" space that particles could interact with. This is where the crackpots seem to be attracted.

    Note: The standard interpretation for the double-slit experiment does not involve a particle "splitting apart" either.

    It is possible to have transverse waves in "submerged fluid dynamics"... if I understand you.
    In water waves, for eg, sub-surface particles travel in circles - so the waves comprise part longitudinal and part transverse motion.
  6. Jul 15, 2014 #5
    This is the closest I could find about "submerged" transverse waves:


    But I don't think that's what I'm looking for. So going back to longitudinal waves, wouldn't sound waves passing through two slits also diffract and interfere on the other side to form interference pattern?
  7. Jul 15, 2014 #6


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  8. Jul 16, 2014 #7

    Simon Bridge

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    To be clear, the interference pattern is in the amplitudes that particles move back and forth (or in the pressure reading on a gauge).
    One could experiment with having sound pressure move things around... see if you can find something to ride a sound pulse say. But this would not have the desired "particle gives rise to the wave" aspect.
    The wave has to have some intimate relation to the particle to get the deBroglie-Bohm effect where the particles wavelength, as well as the slits, determines the details of the interference pattern.
  9. Jul 16, 2014 #8
    I just found out there is a thing called "antibubble", a droplet of liquid surrounded by a thin film of gas.


    So if we vibrated a liquid with some of these antibubbles (or whatever else) submerged in it, wouldn't they be reflecting off that vibration and effectively produce longitudinal waves around them? Then all they need perhaps is a little push in one direction which could disturb its wave dynamic in such way to make the liquid less dense in that direction, and if this new dynamic was stable and self-sustaining the droplets would continue to move in that direction. Or something among those lines.
  10. Jul 16, 2014 #9

    Simon Bridge

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    You need the waves they generate to influence their movement.
    Crunch the numbers.
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