I know that although there are alternatives to this model (such as the torus model) most observations fit with the classic flat infinite universe, which is what I'd like to inquire about. If I understood properly, it means that the Universe has no boundaries whatsoever and, were it possible, one could travel in any direction indefinitely without ever coming back to the starting point. Now, if there is a finite amount of energy and matter in the Universe, would that mean we could reach a region in spacetime (please ignore faster-than-light travel limitations) where there is no matter and energy? Would this inevitably contradict homogeneity? I'm assuming there's a finite amount of energy and matter because I can't visualize how infinite amounts would make the law of conservation of energy any meaningful. Am I missing something very important and/or making a terrible reasoning mistake? By now it should be pretty clear that I'm by no means trained in physics, so I'd really appreciate it if you could keep it in layman's terms. Thank you very much in advance!