A physicist at the University of Maryland says that time travel will never be possible, and he has the physics techno-babble to back him up.
Time travel is a really cool idea. Who hasn't thought about going into the future to check out the flying cars and sex robots, or going back in time to meet your grandparents - but never, ever assassinating Hitler? Unfortunately, actually traveling through time seems to be the real sticking point - we don't have time travelers popping up here and there, so most people consider it an impossibility.
One physicist says that he has final and conclusive evidence that will rule out time travel once and for all. Via the use of metamaterials - artificial materials engineered to have properties that normally do not exist in nature - University of Maryland professor and metamaterial theorist Igor Smolyaninov simulated the flow of time by "mapping light distribution" in one of the aforementioned metamaterials.
Frankly, almost all of the scientific parts in Smolyaniov's research paper go over my head. Hell, even the neat little summarization on PopSci goes over my head - look, I haven't had a science class since High School, okay?
But taking the summary at face value, Smolyaniov found that not only is the flow of time inexorable and unstoppable in its progression (just ask anyone in their 30s and 40s, they'll tell you the same thing), but it's impossible to bend the progression of light (and time) back in on itself - at least, not on its former location.
All you need to know is that Smolyaniov simulated the Big Bang, saw in the scattering of light particles a simulation of the entropic forces that are slowly causing the heat death of the universe, and (apparently) proved that time travel is impossible.
It's kind of a bummer, isn't it? There's good news, though: Smolyaniov's experiment showed that while light can't be bent to go to its former location, it could go to somewhere like its former location - in another dimension.
So time travel is out, but visiting alternate realities and killing their Hitlers for fun could still be in! Keep the dream alive, guys.