By News and Communications Staff
April 01, 2024
Brad Dowden (Philosophy, emeritus) published the encyclopedia article “The Arrow of Time” in the Internet Encyclopedia of Philosophy, an online encyclopedia of 880 peer-reviewed and double-blind refereed articles by university faculty. Many philosophers and physicists have claimed that time has an arrow that points in a special direction. The Roman poet Ovid may have referred to this one-way property of time when he said, “Time itself glides on with constant motion, ever as a flowing river.” However, understanding this arrow is not as straightforward as some believe. For instance, many researchers say a better illustration of time’s arrow should not mention “time itself,” as Ovid did, because time itself has no arrow, just as space itself has no arrow. Experts divide into two broad camps on the question of the arrow’s foundation. Members of the intrinsic camp say time’s arrow is an intrinsic feature of time itself, its uninterrupted passage or flow from the past to the future. Members of the extrinsic camp say, instead, that the arrow is all the processes that go regularly in only one time direction such as balloons exploding but not unexploding, and people getting biologically older, not younger.