First theorem: any consistent formal system F within which a certain amount of elementary arithmetic can be carried out is incomplete; that is, there are statements of the language F which can neither be proved nor disproved in F. Alternative formulation: no consistent system of axioms is capable of proving all truths about the arithmetic of natural numbers.
Second theorem: any system that is strong enough to prove TNT system's consistency is at least as strong as TNT itself.
This theorem is another way of saying that mathematics is just a model, not an absolute truth about the (mathematical) reality. According to Principle of Computational Equivalence, the underlying reality is boundlessly rich and cannot be entirely described by any limited mathematical framework.
The multiverse is infinitely indescribable.
Related:
https://en.wikipedia.org/wiki/Gödel's_incompleteness_theorems