It's possible that one day, the science fiction of "Back to the Future" and "Looper" will actually become science fact.
Scientists performed one of the first time travel simulations, using quantum mechanics to study the effects of sending a particle through a time loop. And it turns out, the simulation essentially confirmed that several prevailing theories about time travel might actually be scientifically possible.
The scientists set out to solve the "Grandfather Paradox" that makes many scientists, like Stephen Hawking, believe time travel to be a load of bull. It asks what would happen if you traveled back in time and killed your own grandfather, something that "Back to the Future" explored when Marty accidentally prevented his own birth.
Think about it for a second without your head exploding: if you killed your grandfather, you'd never be born, meaning you'd never be able to go back in time to kill him, meaning he would survive to have you, so you could go back in time to kill him. Freaky stuff, right?
But scientist David Deutsch proposed a solution to this back in 1991, with something called a "closed timelike curve," or CTC, an anomaly which could happen near a black hole. It's pretty hard to understand, but boils down to the fact that quantum particles allow for paradoxes because their behavior is based on probability, not on the set natural laws.
In movie terms, the CTC is pretty close to "Back to the Future" in how it works. Since there is a possibility you wouldn't kill your grandfather, that's good enough, in quantum terms, to avoid the paradox and let you travel through time.
But like "Back to the Future," you might not get back to your own present day. The "present" you'd get back to wouldn't have to be consistent with the present you left, allowing for that alternate 1985 Marty travels to in "Back to the Future II."
Other scientists prefer something more akin to the "Terminator" and "Lost" model, where everything that happened in the past actually happened, and so the future the time traveler returns to is exactly the same as the one he or she left. Take it away, Hurley.
Pretty heavy, huh? But what's cool is that these simulations actually allow for both of these universes, so that one day, we might be sending robots back to the past to kill people, or, less horrifyingly, send teenagers and their wacky scientist friends back to teach us rock and roll.
Now that's a future I'd want to live in.