# Alternate double slit experiment explanation.

A quite uninformed supposition. But possible?

What if the double slit experiment is indicating a sort of step level of interactions of particles and such? For instance.

A photon travels through a slit. If it goes very close to the center, it does not deviate much. But if it goes through a little closer to one edge, it encounters forces related to the material of that slit edge. I do not know what forces they might be. But the edge is composed of matter. Might there be forces that deflect the particle? Could the forces be in packets of force? Steps of force? So if the particle interacts fully within that area of force, it is deflected a fairly discrete amount. Maybe as you get closer to the matter of the slit, the strength of the packets/steps increases? So there would be a banding effect. The particles going through the slit being deflected in somewhat discrete steps. So there would be some piling up of collisions with the detector at those discrete steps of deflection. Looking like waves.

I imagine some effect of the mass of the material of the slit. Gravitation???

Quantum mechanics. The name indicates quanta of things. Discrete in effect? Or nearly.

I have tried to get more detailed information of slit experiments. But have not had success in finding a middle level of explanation that I can decode. They are very low level, or way over my head. Have experiments been done to specifically see effects of the materials used? Could more or less dense materials cause different band patterns?

Read Richard Feynman’s classic book on QED.
https://www.amazon.com/QED-Strange-Theory-Light-Matter/dp/0691024170

Accessible and covers exactly what you want.

Would the path of the particles be deflected, if opposite charges were put on the sides of the slits? If so. Would the interference bands be distorted as well?

So how does putting a second slit next to the first one change the pattern so much? If each particle only goes through one slit, and doesn’t know about the other slit, then the two-slit pattern should look like a pair of one-slit patterns stacked on top of each other. But it actually looks completely different.

Another question I had. So there are photons emitted at the same time? Each going through a different slit. But close enough in time to interfere?

I am not sure, but I think I read that a single slit can exhibit some banding?

You can get an interference pattern even if the photons are emitted so infrequently that there will be only one photon anywhere near a slit at any time.

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Can one photon, going through one slit, produce a band effect that looks like a wave entering both slits? Or does the wave looking effect have to be built up over time, of many hits of photons?

No - one photon shows up in only one specific place (rather like a particle), but if you send one photon a day through the double slits, after a few hundred days, you’ll see the interference pattern develop.

Really? That is a great tidbit of information I have not come across. But I think that reinforces that it is not a wave effect. How can yesterdays photon, determine todays photon behavior, so it appears as if it is interfering or reinforcing in a wave like manner?

So if you closed off one slit for ten days. The result would look like a single slit experiment. But then swap slits and wait ten days. The cumulative result would look like a double slit experiment?

Yes, really. I’m not sure if the one photon per day experiment has been tried, but experiments have been done with a slow enough rate that only one photon would be in the apparatus at a time. It sounds more like it confirms a wave property - it’s one photon acting like a wave, interfering with itself.

No. It would look like two overlapping single slits (or as if you moved the single slit). Even with one photon per day, it matters if there are two slits.

Wow. Thank you for these bits of information. I will look into this aspect more. Can you point me in the direction of an article about how the photons are generated and counted?

You just need a feeble enough source. Keep turning it down (or stick absorbing stuff in the way) until the average rate is low enough. You can make a detector out of any device that registers individual photons. Any modern digital camera has a quantum efficiency high enough to work. You don’t need photomultiplier tubes anymore. You could perform the experiment at home with no expensive gear.

Frankly, these are the fundamental aspects of the double slit experiment, covered by any introductory book on quantum mechanics, or any general-public explalanation of the experiment. Including the wikipedia entry for “Double-slit experiment”.

And a “feeble enough” light source doesn’t need to be very feeble at all. Even if you’ve got a whole lot of photons per second, well, it takes light a whole lot less than a second to make it all the way through your apparatus, and clear the way for the next one.

If you want to give particles always well-defined trajectories and be compatible with the predictions of quantum mechanics, it is possible, and you will end up with something like this for the double-slit experiment:

https://www.researchgate.net/figure/Possible-Bohmian-trajectories-in-the-double-slit-experiment-from-C-Philippidis-C_fig1_226707799

If anyone is still listening.
No idea how to word a search for this, so hoping you folks might know. Has anyone performed the slit experiments with the slits being placed in detectors? Such that any particles/waves that don’t go through the slits. Instead hit the detectors that the slits are in. Maybe detectors in positions capable of detecting anything that does not go through the slits.
Your replies were great. Especially the one that enlightened me to a particle interfering with itself. Did not know that at all. I also wondered if a pair of fiber optic filaments, could act as slits. Two together at the emitter, if that is possible to capture the emission. Then branching apart facing the detector screen. A portion of a wave going through both. Then splitting before emitting to the screen.

Today’s photon has no idea where yesterday’s photon went; each is just choosing a spot to land, independently. 1t’s random, but with a big chance to land in the center, a really tiny tiny chance to land just outside the center, medium chance to land a little farther out, super tiny chance to land yet farther out, and so on. So if you send one photon, you’ll get a dot somewhere (probably in the center but maybe somewhere else). Send another photon and you’ll get another dot (again probably somewhere in the center). Keep that up for a bunch of photons and you’ll get a bunch of dots in the center and a few outside of it. Send a even more photons, and the center will be pretty much all dots, with almost no dots just outside of it, then a few dots a little farther out, none yet farther out, etc. With a ton of photons, you get solid white in the center, and interference bands of light and dark as you move outward from the center.

So each photon is interfering with itself, to decide the chances it will land in any particular spot. It then randomly chooses a spot based on those chances.