As Albert Einstein's general theory of relativity turns 100, here are five ways it has made the universe – in reality and in science fiction – a more interesting place.

Einstein’s theory of general relativity suggests that our universe originated in a Big Bang. But black holes, and their gravitational forces, challenge the limits of Einstein’s work.

For over a century, Einstein's general theory of relativity has been key to understanding gravity. But new research suggests this theory "glitches" in the farthest reaches of space. That doesn't ...