The grandfather paradox is just one of the thorny logical problems that arise with the concept of time travel. But one ...

While parallel universes are a staple of science fiction, there are some real scientific theories to support them. But if parallel universes do exist, could we ever travel to them? It certainly wouldn ...

Today, space travel for the average person is no longer a matter of "if" but "when," thanks to the imaginations of self-funded business magnates with an eye on the sky. Space is the tourism ...

One of the most famous paradoxes ever, the grandfather paradox, cautions against making changes that could break the timeline if you were to ever travel back in time. But, according to one scientist, ...

Black holes, vast regions of space with gravity so strong that even ... offers a potential pathway to unlocking the mysteries of time travel." ...

Vanderbilt University physicist Lorenzo Gavassino isn't so sure this is as big an obstacle as time-traveler pessimists have made out. In a recent examination of the finer details on entropy, space, ...

With these vast distances and the time involved, manned space travel to other stars seems unlikely with our current technology. Watch the video below to see how our current space ships developed ...

(Mark Kelly, now a U.S. senator, also spent a brief time in space ... not all — underscoring the potential health hazards of space travel, many of which are unknown. These will ratchet up ...

So when we travel to zero gravity environments like the International Space Station or limited gravity ... and that's because there's never a time here on Earth where we're not exposed to zero ...