While still theoretical and highly debated, the mathematics of string theory suggests that there could be multiple dimensions of time. Columbia University's theoretical physicist Brian Greene ...

String theorists are betting that extra dimensions do indeed exist; in fact, the equations that describe superstring theory require a universe with no fewer than 10 dimensions. But even physicists ...

In a groundbreaking exploration of physics, researchers have revealed a way to extend Albert Einstein's special theory of relativity ... space and time into a four-dimensional continuum.