In the beginning, there was … well, maybe there was no beginning. Perhaps our universe has always existed — and a new theory of quantum gravity reveals how that could work."Reality has so many things that most people would associate with sci-fi or even fantasy," said Bruno Bento, a physicist who studies the nature of time at the University of Liverpool in the U.K.In his work, he employed a new theory of quantum gravity, called causal set theory, in which space and time are broken down into discrete chunks of space-time. At some level, there's a fundamental unit of space-time, according to this theory. Bento and his collaborators used this causal-set approach to explore the beginning of the universe. They found that it's possible that the universe had no beginning — that it has always existed into the infinite past and only recently evolved into what we call the Big Bang.Related: ​​Big Bang to civilization: 10 amazing origin events