Physicists describe gray holes as objects sitting just 5% above the Schwarzschild radius — close enough to a black hole that light can barely escape. Unlike black holes, matter falling in does not ...

Black holes are places where gravity is so powerful that nothing — not even light — can escape. Rather than being empty, black holes are chock full of matter that gets squeezed into a teensy space.

For decades, black holes have stood as the most enigmatic objects in the universe, defying our understanding of space, time, and matter. Yet, some physicists propose an even more mind-bending idea: ...

An ambitious project to map the density of every object in the cosmos has yielded a few surprises, and may help lead to new ...