Has anyone ever (or does anyone know of anyone who has ever) performed the double-slit experiment inside a well-shielded Casimir cavity? I think that'd uncover some interesting aspects of what we consider to be the wave-particle duality of light (and/or electrons).

I contend that electrons are particles (they have a rest mass, after all, and it's now been proven that they reject QVZPE field modes longer than their radius, as all matter does, which is why those out-of-phase QVZPE field modes impinge upon the electron in the first place, and part of the reason a magnet's magnetic field is coherent (a "field" (for want of a better descriptive term) of electrons all rejecting out-of-phase QVZPE field modes longer than the Compton radius (acting much like a Casimir cavity) damps electron precession as a whole in the bulk of the magnet, allowing the Larmor radiation thrown off by those electrons to be more coherent and thus perceivable at the pole faces)... they're just so small and light that the QVZPE field modes that destructively interfere with its orbit about a nucleus make it appear as though it were of a similar nature to those QVZPE field mode electromagnetic waves that are impinging upon it. The electron wants to make a nice circular orbit about the nucleus, but the destructively-interfering QVZPE field modes toss it about, necessitating that we use quantum superposition to estimate its most likely position simply because we have no equipment that can zoom in enough and which has a fast enough data acquisition speed to accurately determine its position.

For free electrons, I further contend that what we're seeing in the double-slit experiment with electrons is a manifestation of the electron being impinged upon by those destructively-interfering QVZPE field modes. We're not seeing the electron as a wave, we're seeing the QVZPE field modes (ie: electromagnetic waves) impinging upon the electron such that it's "tossed" upon those QVZPE electromagnetic waves. So we're actually seeing the anisotropy of the QVZPE field, said anisotropy caused by the electron passing through the QVZPE field on its way to the target and interacting with the QVZPE field... it's kind of like that "random walk" game called Plinko at carnivals (you put a disc in at the top, it bounces off of pegs on its way down, you get points or a prize if it lands in a certain spot)... except replace the disc with the electron, and the pegs with the QVZPE field modes impinging upon that electron.

By conducting the double-slit experiment in a Casimir cavity such that the QVZPE wave modes that predominantly destructively interfere with electrons is damped, we might be able to determine once and for all whether an electron is a particle or a wave.

Interestingly, Einstein hinted at this:
http://www.bourbaphy.fr/grangier.pdf

Quote

Interestingly again, he goes even further in the 1909 conference (as well as in another article [3] published also in 1909), and identifies two basic contributions to the fluctuations of radiation: one is a “particle-like” contribution, that we would call now shot-noise, and the other one is a “wavelike” contribution, which is due to random interferences, and that we would call now speckle-like fluctuations, or the Hanbury-Brown and Twiss effect.

I haven't seen anything about the experiment being done in a Casimir cavity. I have, however, seen an explanation that makes sense to me. The particle (quanta) is surrounded by fields much like a magnet. When the quanta goes through a single slit the nature of the fields keeps the quanta centered in the slit thus it appears as a particle. When the quanta goes through a slit in a multi-slit experiment it still only goes through one slit but the field surrounding the quanta gets sliced by the other slits such that the field is now in separate planes and these planes can interfere with each other making it look like a wave. I'm not sure that is exactly the right description but there is a video. It's a bit tedious but very much worthwhile.

The single/double slit explanation starts at 37:07 but the entire video is useful as well as the entire series - parts 1 to 3 so far.

The Primer Fields Part 3

Yeah, that's what I'm thinking. An electron is a fundamental particle, its charge is indivisible. The only explanation that makes sense when taking that into account is that the electrons are riding on the waves of the QVZPE field before they hit the double slit (and after, of course), and thus sometimes they get diverted a bit left or right as the QVZPE waves are perturbed by the electrons passing through them before hitting the double slits. You take away one of the slits, you take away the interference pattern of the QVZPE field, and thus you only get one stripe of electrons on the collector. This is described by De Broglie's and Bohm's Pilot Wave Theory, which was initially rejected in favor of the Copenhagen Interpretation's "Shut Up And Calculate" contention that particles are waves and waves are particles, etc., but which had a major new experiment corroborate it in 2014. You'll note that Einstein himself supported Pilot Wave Theory, encouraging Bohm to develop it further from De Broglie's initial findings.

This means Einstein was yet again right... God doesn't "play dice" with the universe. It is deterministic in nature, but we simply don't have the ability to determine the beginning state of even a simple quantum system (let alone the entire universe) sufficiently to track how it will evolve at any given moment. The failing is on our part, and the Copenhagen Interpretation was our attempt at explaining that failing away. But science marches onward toward the ultimate truth, and the Copenhagen Interpretation is falling by the wayside. In time and with sufficient scientific progress, we will be able to determine a system's beginning state sufficiently to not only track its progression but to predict its outcome at any given point in time.

https://gravityandlevity.wordpress.com/2009/05/10/surfing-and-the-double-slit-experiment/

Note that the post above was from 2009, back when physicists weren't sure if the QVZPE field was a reality or merely the result of their mathematics. The QVZPE field has since been confirmed to exist, and in fact virtual photons have been concretized from the QVZPE field using Dynamical Casimir Effect by Chalmers University in 2011. Photons are the easiest to concretize, they require less energy, but I expect eventually we'll be able to concretize pretty much any element from the QVZPE field.

quite a nice video, good to have some insight into the double slit paradox.
I couldn't understand why higher energy light bent more in the prism though, there was something missing there or I missed something. Quite a long video though, the information is presented in a very slow way with quite a bit of repitition, it could be compressed quite alot , but still worth watching it.
Heres a couple of thoughts on the vids:
1. if there are circulating wave like particles in the em fields, since they are already travelling with the speed of light, on one part of their circulation they will be slower than the speed of light, and on another part of their circulation they will be faster than the speed of light ( since the velocities are summed)......leads to another paradox as they would violate 'c' as max speed.
2. he mentions that how far you can divide up the wave particles, is not known, as in there may or maynot be a smallest particle size............or it may go on forever.....or does the plank length hold true.
3.he discusses wavelength and speed changes as em waves are slowed, but does frequency remain unchanged? Is frequency a sort of constant once a wave is created?