[ELI5] how do we prove that something goes to infinity or – infinity since we can’t observe it?

Question

For instance how do we know that something weird doesn’t happen at some insanely large number?

In: 3

Answer 1

In maths, there’s no observation to do. It’s just a language at the end of the day. It does nothing weird like that because it is just a description and iteration of logic

In physics, this absolutely could be and probably is true. We can only be certain of the laws of physics in the place where we observe them. There’s some interesting theories about how we might be living in a void and the rest of space might have a different speed of light or strength of gravitational force. We also think that *a lot* of weird things happen on event horizons of black holes, and we have no idea what kind of things could be beyond the observable universe and no reason to suspect that there’s nothing else out there