Physics is the study of how. The questions How and Why don’t have much difference in context of physics.

Example :- Why is Earth orbiting sun ?
Gravity.

How is Earth orbiting sun ?
Lo mismo, Gravitacion.

But Metaphysics, is the a branch of physics that concerns itself with the why of how’s in physics. Sort of like, Physics of Physics itself. It hasn’t found much attention other than from Philosophers and Cocktail party dinners. One such topic of prominence would be Quantum mechanics Interpretation. Sort of like Philosophy, it doesn’t require much maths and can be a fun topic for chit-chat among Mortys. Because Ricks are Nihilistic and don’t give a pittance.

Bohr interpretation :- The one that is calculative and makes much more sense. Named after Bohr, but the main man, in my opinion was Max Born. He says that, if I assume a proper quantum system, properly quantum without any semi classical stuff going on, the states of the system must form a Hilbert space. It would be fine if they just formed a vector space, but that would only work with statics. The dynamic part requires us to calculate inter-state transitions and that requires the concept of inner product and Hence, a Hilbert space.

Like with any vector space, you have the option of combining two or more States and that would still be a state of the system. The coefficients of mixture of states maybe interpreted in relevance to probability. If that system were to function like a pin ball machine, probability of landing that state is the square of that coefficient. From that moment, we step into the zone of probability. For conserved quantum systems, meaning the system doesn’t lose quantum states over a period of observation, the governing principle would be unitarity. And Hence, the mixing or transition operators must be unitary.

Many worlds interpretation :- In the context of QM, this just seems like a far fetched idea. Instead realizing the working as probabilities, this says that each outcome is realized in it’s own universe. So for an 2 states system analogue in Born interpretation, Many worlds or DeWitt interpretation would have 2 universes corresponding to 2 pure states and infinite ones correpsonding to infinite ways of mixing two states to obtain total probability to be one. This interpretation is not of very much experimental value.

In my humble opinion, theorists are sinners for we cannot resist the provoking of thoughts. Experimentalists are the angels in aid of the God. If you chose this interpretation to work with, you haven’t left much for god to salvage, you know.

String theory also offers a possibility along this line of thought.
In a string theory, only free parameter is the Tension of the string or rather, the Universal Regge Slope.
This free parameter in turn determines the observable constants like Planck constant, charge of electron, Cavendish Constant etc
So, in a DeWittian way of thinking, I am tempted to say that for a particular Regge Slope, I will have a universe with a particular set of constants.

Certainly, physics will be different among those universes.

This is the Multiverse theory. This discussion is fun and, not at all productive in my opinion.

But for the sake of playing along, We all are from Earth 616, the same one that houses Kal-El of Hope and Rick Sanchez of C-137.
We are uniquely identified by a combination of our Justice League Society and Trans-dimensional Council of Ricks.

So guys, that’s all for this post.