 However, current physics can only describe the early universe from 10−43 seconds after the Big Bang (where zero time corresponds to infinite temperature); a theory of quantum gravity would be required to understand events before that time.Nevertheless, many physicists have speculated about what would have preceded this limit, and how the universe came into being.For example, one interpretation is that the Big Bang occurred coincidentally, and when considering the anthropic principle, it is sometimes interpreted as implying the existence of a multiverse.