What is time? If it exists, can it be measured? And if it can be measured, does it occur in just one universe or several?
Over 600 curious people came out to OISE to hear the answers to these questions at the Great Time Debate, an event co-hosted by the Centre For Inquiry and the University of Toronto Secular Alliance. Cosmologist J. Richard Bond and philosopher James Robert Brown, both from U of T, joined Lee Smolin, a physicist from the Perimeter Institute in Waterloo, Ontario. Dan Falk, a science journalist and the author of In Search of Time, moderated the talk.
“I think it’s safe to say that as long as our species has existed, our ancestors have been fascinated by the natural cycles that we see, the cycles of time,” Falk said in his introductory remarks, citing mechanical devices and theoretical models that people built to measure time and to explain it.
Einstein’s theory of relativity destroyed Newton’s idea of a “universal now,” the idea that time operates the same way in all universes, Falk said. Each part of the universe has its own concept of now and its own way to measure time. Falk also picked apart the metaphor of time as a river.
“A river flows with respect to the shore; what could time flow with respect to?” he asked. “ A river flows at a rate you can measure […] at what rate does time flow?”
These questions framed each panelist’s arguments for their position on the event’s topic.
According to Bond, our universe is one in a series of multiverses born of eternal inflation. Eternal inflation results from oscillations in the structure of each universe, including our own. Each universe has its own clock—in this case, time is completely relative and past, present, and future collapse.
Brown’s view of time rested on an argument for “the relativity of simultaneity.” All times are happening at once, he said, which means that past, present and future are all happening simultaneously and are all real.
Smolin disputed the idea of simultaneous nows by positing a “Darwinian cosmology,” where laws and universes evolve. The only real time is the present. He took issue with the idea that we happen to exist in a habitable universe.
“We are scientists and must do better than theology. These views do not yield testable results and are therefore not science,” he said.
An audience member asked each presenter to sum up their concept of time with the phrase “Time is.” Bond replied that time is the fourth-dimension and said, “We do not have control of the horizontal or the vertical,” a passing reference to the sci-fi show The Outer Limits. Brown shrugged, threw his hands up in the air, and said, “Time is obscure.” Smolin paused for a moment before announcing with a smile: “Time is real.”
