From Isaac Newton’s ‘absolute space’ and ‘absolute time’, which envisioned the two phenomena as fundamental and separate, to Albert Einstein’s ‘spacetime’, which condensed them into a single concept, the relationship between space and time has been the mystery driving fundamental physics for more than four centuries. And over the past several decades, some physicists, including Lee Smolin of the Perimeter Institute for Theoretical Physics in Canada, have come to believe that the fabric of reality is perhaps due to be torn into yet again. In this interview with Robert Lawrence Kuhn for the series Closer to Truth, Smolin discusses how developments in quantum mechanics have left physicists with questions that special relativity can’t seem to accommodate, and why the solution might be a conception of reality in which time is fundamental, and space emergent.