John W. Moffat has been a professor of physics for more than three decades. He is currently Professor Emeritus at the University of Toronto, a member of the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, Canada, and adjunct professor in the physics department at the University of Waterloo. Moffat is well known for his alternative theory of gravity to Einstein's general relativity. He is the author of Reinventing Gravity: A Physicist Goes Beyond Einstein and Einstein Wrote Back: My Life in Physics.