t turns out the headline answer is brutally simple: a universe that truly began cannot also be actually infinite. If space were already infinite at the first instant, you’d be asking reality to do the impossible—jump from non-existence to infinite existence in zero time. That’s the “born infinitely old” paradox in disguise. The math that describes expansion in an infinite model is fine, but as a story about origins it collapses: you don’t explain an origin by declaring you had infinity from the start. Even inflation doesn’t rescue this—it just hides the boundary in a special inflaton setup. The upshot: infinity is a great calculator’s trick, not a credible birth certificate.
Flip to the finite picture and everything snaps into focus. Edges give physics teeth: information stays bounded, probabilities stay meaningful, and the arrow of time emerges cleanly from a low-entropy beginning. Causality has room to operate, predictions stay testable, and “coincidence” goes back to being evidence instead of inevitability. Infinity belongs to math; beginnings belong to reality. And the universe doesn’t need to be endless to be magnificent—just coherent enough to let us measure it, understand it, and be awed by it.