The Big Bang Theory posits that matter began from a singularity and expanded outward, thus you would surmise expanded yet bounded matter by the “big bang,” but the theory allows that matter is unbounded, a limitless cosmos, so why do they allow that contradicting the logic? It’s because to admit bounded matter is to admit gravitational time dilation during the expansion of matter such that the distant stars billions of light years away are actually only thousands of years old.