Sending a Photon Backwards in Time

Dr. Seth Lloyd
Massachusetts Institute of Technology

Friday, April 23, 2010</strong

2:30 PM – Salvatori Auditorium (SAL-101) Lecture
3:30 PM – Salvatori Auditorium (SAL-101) Reception

Ever since Einstein, physicists have argued about whether time travel is consistent with the laws of physics, and, if so, how it might be accomplished. This talk presents a new theory of time travel based on quantum teleportation. Unlike previous theories, the theory can be tested experimentally. I report on an experimental realization of the “grandfather paradox:” we send a photon a few billionths of a second backwards in time and have it try to “kill” its previous self.

Seth Lloyd was the first person to develop a realizable model for quantum computation and is currently working with a variety of groups to construct and operate quantum computers and quantum communication systems. Dr. Lloyd is the author of over one hundred scientific papers, and of Programming the Universe, (Knopf, 2004). He is currently the director of the W.M. Keck Center for Extreme Quantum Information Theory (xQIT) at the Massachusetts Institute of Technology.