Travelling forward in time is theoretically possible, according to theoretical physicist Michio Kaku. Because of Einstein’s Law of Special Relativity, spending time in space can actually slow down time; the closer to the speed of light something moves in space, the slower time passes. Astronaut Scott Kelly, who spent a year in space, actually got a few microseconds younger and is now technically a different age than his twin brother who stayed on earth. Someday, Kaku theorizes, when we can travel at the speed of light, we will be able to go into the future. Hence, the outlandish part of BACK TO THE FUTURE isn’t time travel itself, but the fact that Marty, Doc Brown (whose poufy white hair mimics Einstein’s), and their dog Einstein can travel both forward and backward in their nuclear powered DeLorean car. The theoretic feasibility of time travel backwards has been disputed among physicists and mathematicians, including Steven Hawking, and using quantum mechanics scientists are still trying to resolve how it might work.

Watch Kaku talk about BACK TO THE FUTURE below:

The Museum of the Moving Image will screen BACK TO THE FUTURE in 35mm on Friday, July 1 at 7pm as part of a series of films which were originally released over July Fourth weekend.

Cover image taken from a 35mm film print of BACK TO THE FUTURE. Photo by Carolyn Funk.