Many-world interpretation: simple physics explanation?

Question

We went a little off topic in physics class today and my teacher was explaining how quantum physics explains the idea of parallel universes. She believes in a idea called many world interpretation where the universe consist of timelines that continuously splits leading to an $\infty $ of parallel universes. She says that it is because particles have wave properties and waves can be in two places at once. So all particles appear in multiple places, but in its own universe. I want to know how does physics explain this theory of parallel universes? I understand the timeline concept, but not the physics. Any explanation will be very much appreciated!

If we are made out of particles then we exhibit wavelike characteristics, right? So, then can theoretically(if quantum theory is proven to be true) be an infinite number of particles that are us, just in different parallel universes which we can't observe?

Can anyone explain to me the physics behind this MVI? I will try to follow each and every answer to the best of my ability.

Below is a picture of the timeline! It keeps on splitting and we remain on one, other version of ourself remain on others? :

Side Note:I looked at wikipedia, but it only refers to a wave function and doesn't give a concrete understanding

Answer 1

You essentially answered the question yourself when you said it is because quantum particles are waves and can be in more than one place at once. The physics, or mathematics of this is the mathematics of waves, superposition, linear algebra. It's essentially quantum mechanics. So study quantum mechanics. I understand the literature on quantum mechanics isn't exactly enlightening. It requires deep thought. I'm working on presenting these sort of ideas in a more intuitive way. However for the time being, I suggest to learn more quantum theory if you are mathematically inclined. If not, then you'll have to wait.

Answer 2

As far as I know the parallel universe (or multiverse) theory has two reasoning:

1- How can we get rid of the idea of god?
In the universe we live, the physical laws seems as if they are fine tuned for the form of life we know to exist. Of course this cannot be true!!! Therefore there must be some other (infinitely many, to be precise) universes with, say, gravitational constants varying all over the place where primates could never stand up, etc.

2- How can we make sense of the measurement problem and probalistic nature of quantum mechanics?
The best example is the most famous cat on the planet. Until the box is open the cat is both dead and alive (technically speaking in a state with 50% chance of being dead and 50% alive). When we open the box we find the cat, say, dead in our universe. There is a possibility that the cat is alive in another universe.