Without a constant for dark energy, Albert Einstein’s original fear could be true: that gravity will pull the universe back into itself, leading to a Big Crunch that will reverse or undo the Big ...

Einstein's theory of general relativity suggests that the "memory" of ancient events, such as black hole mergers, may be etched into the fabric of space-time by gravitational waves. New research ...

With no outward pressure from fusion to counterbalance gravity's inward pull, the star condenses and collapses in upon itself. Despite their small diameters—about 12.5 miles (20 kilometers ...