"Everything seemed to be explainable by math."
Not true, when infinity is involved, maths becomes utterly useless.
Observe;
x = 0.9(recurring)
10x = 9.9(recurring)
9x = 9
x = 1

Maths has failed to explain how we got from 0.9999... to 1.

Therefore, a true replica of the universe can never be made. However, it can be made so big that we would never notice that it is finite. Or the boundaries can be programmed to annihilate anything that comes into contact with them. Like antimatter for example.