The theory is that space-time is infinitely large, and there is an infinite amount of energy within it (afaik). Actually the theory (General Relativity)is that

The theory is that space-time is infinitely large, and there is an infinite amount of energy within it (afaik). Actually the theory (General Relativity)is that a closed universe should have measurable positive curvature, unless it has some weird topology that isn't "naturally" expected (although everything consistent is possible of course). We measure a curvature approximately 0, so that would imply the universe is in fact infinite. Since it is also expected to be isotropic (have approx. the same distribution properties everywhere and in any direction), then it also would have infinite energy. There's no proof of this infiniteness of course, it is only the most natural expectation (most natural of course is always controversial since some physicists probably don't like infinite universes). What we observe, and what can affect us in any way, is of course the 'Observable Universe', and up to its edge it appears boringly uniform (except for a minor anomaly[1]), arranging in a web of huge filaments[2] that extend across its entirety. [1] https://en.wikipedia.org/wiki/Axis_of_evil_(cosmology) https://en.wikipedia.org/wiki/Axis_of_evil_(cosmology) [2] https://en.wikipedia.org/wiki/Galaxy_filament https://en.wikipedia.org/wiki/Galaxy_filament