Scientists now have a fairly thorough understanding of the event known as the Big Bang, but what, if anything, came before it? According Tim Maudlin, professor of philosophy at New York University, modern cosmologists must consider two possibilities: that the universe was born of out nothing, or that the Big Bang was preceded by ‘another state’. However, both possibilities – that time simply began, or that an infinite amount of time has elapsed – provoke discontent among scientists and philosophers, which leaves the door open for a range of competing theories.