November 11, 2010 —
In a recent issue of Science News, the lead article of the "In the News" section by Laura Sanders concerns a new quantum-mechanical hypothesis about how time travel could actuallly work (http://www.sciencenews.org/view/generic/id/61301/title/Taming_time_travel).
This work was presented in an Electrical Engineering Distinguished Lecture in Spring 2010 by invited lecturer Seth Lloyd of MIT, and the Science News article has two paragraphs quoting the reaction of Todd Brun from the Ming Hsieh Department of Electrical Engineering. Professor Brun, who has also written papers on the subject, pointed out that the description of time travel presented by Lloyd and his co-authors can still lead to very odd behavior, by our usual everyday standards. For instance, the possibility of time travel could affect the probabilities of events now, even if time travel only occurs in the future.
As quoted in the article, Professor Brun concludes that despite these oddities, the new results form "a nice consistent loop," and make up "a really interesting body of work." However, since no one has any idea how to build a time machine in practice, he adds, "I don't expect these will be tested anytime soon. These are ideas. They're fun to play with."
Todd Brun is an associate professor in the Ming Hsieh Department of Electrical Engineering, and received his Ph.D. in Physics from Caltech in 1994. Since then, he has held appointments at the University of London, the Institute for Theoretical Physics in Santa Barbara, Carnegie Mellon University, and the Institute for Advanced Study in Princeton.