A new solution to Albert Einstein's theory of general relativity suggests hypothetical gravitational stars that look like black holes could be nested within one another. When you purchase through ...

New impressions A visualization of a curved space–time “sea” from the general-relativity simulations carried out by the authors.(Courtesy: James Mertens) From the Genesis story in the Old Testament to ...

The accelerating expansion of the universe could be explained by modifying general relativity so that gravity has mass – or so thinks a small group of physicists. Matthew Francis reports What lies ...