Einstein's theory of gravity — general relativity — has been very successful for more than a century. However, it has theoretical shortcomings. This is not surprising: the theory predicts its own ...

BOULDER- Black holes, time travel and E= mc^2. They are all related to Albert Einstein's Theory of Relativity. How many of us, though, can actually explain any of it? This year, Einstein's theory ...

For years, astronomers have wondered why real-life versions of Tatooine are so rare. With thousands of confirmed exoplanets and countless binary star systems in our galaxy, planets orbiting two suns ...