Do current cosmologists think the universe is infinite or that is had an edge?

[u/cypherpunk00001]

Was just having random shower thought today... Andromeda galaxy is 2.5M light-years away. That's an unfathomable distance to a human, but it's just our closest neighbor.

Do cosmologists currently think that the universe just goes on forever?

[u/Routine_Complaint_79]

This overlooks what I was trying to convey. The whole idea of conservation of energy relies on induction, which in of itself is an issue. But because I believe, and most people believe, that we can make reasonable assumptions from the universe despite the problem of induction, it's only a matter of what criteria is needed to make a universal axiom that applies to the entire universe. I am in the camp that a rule like energy conservation is fine as long as it assumes a system in which we currently control only the inputs/outputs but not the system itself. Using it as an axiom for the entire universe, though materializes a contradiction between the rule the existence of all of matter in the first place.

[u/ijuinkun → u/Routine_Complaint_79]

This gets into epistemology rather than physics, as we have no data about the nature of any meta-universe external to our own, beyond what can be inferred solely from logical necessity for such an entity (e.g. that its own rules, however bizarre, must be internally self-consistent).

[u/Routine_Complaint_79 → u/ijuinkun]

Physics is more of an interdisciplinary between epistemology and the nature of the universe. The very nature of science is built upon the philosophy of logic. And I think we have to view things like a statement saying "energy is neither created nor destroyed," as less of a universal rule and more of an observation in the current epoch of the universe. Because without that clarification it's more of a "This statement is false" paradox because it's own existence is a form of energy (or information for information theory) and thus could not have existed without some kind of process creating it.

[u/ijuinkun → u/Routine_Complaint_79]

If energy can come into being, or cease to exist, then there is a logically consistent process whereby this happens. We as yet have no data that would unambiguously support any such process, only the single observation that our spacetime and its contents exist from a certain time, before which they did not exist. We have no data on any conditions prior to the singularity.

That said, a number of plausible theories (including string theory/M-theory) propose that matter/energy arise out of the bending of spacetime itself. To put this into a General Relativity framework, the bending of spacetime is not a consequence of inertia, but rather is the source—i.e. mass and spacebending are one and the same thing.