So according to Max Tegmark, the highest level of multiverse is mathematical. Obviously this is very controversial as this goes into the realm of metaphysics. I wonder what this community thinks about it. Personally, this makes sense. Everything in physics is described using math. For example, consider two objects under gravitational attraction. The amount of force/accelerating is described using math. The colors of the objects is described using mathematical wavelengths. There is distance between them, which is geometrical. The mass is measured with numbers. The idea that these are masses and not something else is just categorization under Set Theory. Any subjective opinions of those masses are just patterns of neurons firing in our brains in a very mathematical way. Since this universe is described very well mathematically, then maybe mathematical structures subsume all universes/reality.