Albert Einstein's general theory of relativity is a landmark in our understanding of the universe. It gave rise to the notion of a spacetime continuum against which all physical phenomena play out.

Einstein's inexhaustible field equations just keep on predicting weird stellar objects, and the latest one is a doozy—so strap on your helmet, inside of which is another helmet, encasing still yet ...

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American Only a year before, Einstein had finally ...

According to Einstein’s general relativity, nothing is ever seen crossing a black hole’s event horizon. From the outside, objects appear to slow down, redshift, and freeze in time before fading away.