Passage in the Block

Tim Maudlin (New York University)

Abstract. Over many years, different views about the nature and structure of space and time have acquired various names and associations. In one common usage, it is said that one sort of view accepts a “block universe” or is a “B-theory”, and therefore rejects the notions of a “passage” or “flow” of time, while a “dynamical” or “A-theory” account of time accepts that time “flows” or “passes”. Further, it is also often added that according the “block universe” view there is no intrinsic direction of time, while according to a “dynamical” theory there is. Finally, it is often said that present physics (especially Relativity) endorses or entails a ‘block universe” theory, so anyone desiring to maintain that time “passes” must modify present physics. I will argue that all of this is misconceived. There is no incompatibility between a “block universe” and “dynamical time” or “passage of time”. Further, nothing in physics precludes, or even casts doubt on, an intrinsic direction of time. If one wants to speak of a block universe, there is passage in the block and directionality in the block. I will briefly discuss a way of characterizing the geometrical structure of space-time that can make this evident.