[aeternum]

The concept of a field can be described using mathematics but does that really mean mathematics is actually what the universe is made of?

Suppose for example we found that protons, neutrons, and electrons really were fundamental. Their behavior can be described with mathematics but wouldn't we say it's still the elementary particles that our compose our universe?

[criddell]

Tegmark's theory says exactly that - the particles are ultimately mathematics. Not that they can be modeled with mathematical methods, but that they are actually constructed from mathematical structures.

It's definitely not a mainstream theory.

[goatlover]

What does the mean, though? Mathematics as we understand it is an abstraction. If the universe is fundamentally abstract, what breathes fire into the models? Consciousness?

[wcoenen]

Modal realism. A mathematical structure is "real" to its conscious inhabitants (if any), and merely an abstraction from the perspective of those who are not, i.e. the inhabitants of other mathematical structures.