Does the experiment where a single photon goes through 2 slits really show the universe is constantly dividing into alternate realities?

Question

Probably not well worded (bad at Physics!)

In: Physics

Answer 1

There are a number of competing theories about what happens on a quantum level. There’s what you’re suggesting, the Many Worlds Theory, where every possibility is accounted for in timelines that we can’t experience, but there are two other bigshots that take up a lot of the stage.

We have the Copenhagen Interpretation where particles are undefined probability waves until the moment that they interact with a field or another particle, causing the wave function to collapse into a single defined state.

The more recent addition is Pilot Wave Theory where particles are always defined but they can only exist in certain states or locations, as dictated by the quantum wave function. Interaction alters the wave function, and the particle ends up following this new path.

All three are enticing theories but break down in unique ways when you look too closely under the hood. As things stand, they can all be valid with certain tweaks that we can’t figure out right now. At the same time, though, they can’t be used as a definitive model for how the universe works.

So, to answer your question, the double slit experiment doesn’t show that there are constantly splitting universes. It only shows that there’s something weird going on at those scales and that Many Worlds might be the way to explain it, if we can somehow prove it.