system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How did they predict existence of subatomic particles, black holes, multiple universes using maths and equations?
gpt
> subatomic particles

They didn't predict those with math. They were largely experimentally discovered. Thomson's cathode ray experiment found that there were negatively charged subatomic particles we now call electrons, for example. 

> black holes 

These were first thought of from Newtonian mechanics by Laplace (and others?), but it was really just an idea. After Einstein produced the general relativity theory, Schwarzschild predicted the limit at which a black hole could form. 

> multiple universes

Those aren't mathematically predicted either, they're really outside the realm of science.