Time travel is one of the hallmarks of science fiction, but many time-travel-based movies have plots that leave one with a headache just thinking about them. What if you could travel into the past, ...

The idea of a particle that races faster than light has long fascinated physicists. Known as the tachyon, it was originally dreamed up to help untangle paradoxes in quantum theory and relativity.

There’s little more satisfying than a solid sci-fi series, except perhaps a sci-fi series that brilliantly explores the concept of time travel. Any sci-fi fan can tell you that not all time travel ...