Is the universe infinite? The answer gets weird fast
Measurements of ancient light from the cosmic microwave background suggest that the universe is remarkably flat. But that does not prove it is infinite, because the observable cosmos could be only a small patch of a much larger curved universe. Space could even be flat while wrapping around on itself in exotic ways.
原文：https://www.a8q9.cn/en/article/is-the-universe-infinite-the-answer-gets-weird-fast-9b2156.html