The universe would have to experience big bang and big crunch over and over again
Nothing can arise out of nothing. Everything that is there must always have been there in some form. That means that what is there must also exist infinitely in some form.
Thus, all matter and energy in the universe should have always been there and will always exist. Given the probability of a big bang before the creation of the universe, a big crunch would be the most logical fate of the universe. Since we would then be living in a closed universe, this means that if only you traveled far enough in a certain direction, you would end up where you left off. In this way, the universe is simultaneously bounded and infinite.
