White holes would be even stranger than black holes. They would still have singularities at their centers and event horizons at their borders. They would still be massive, gravitating objects.

White holes are theoretical cosmic regions that are opposite to black holes. Just as nothing can escape a black hole, nothing can enter a white hole.

The bold question-askers at What If imagine the cosmic consequences of a collision between a black hole and a white hole.

At the moment, white holes are theoretical mathematical concepts that astrophysicists use to help further study black holes in space. To study a black hole, scientists mathematically explore the ...

The major difference between black holes and white holes is their formation. We know, thanks to the work of J. Robert Oppenheimer and collaborators, that when a massive star undergoes a complete ...

White Holes, like Rovelli's other works, is remarkably short — less than 200 pages. But the clarity of his explanations is unparalleled. As a scientist who is also a popularizer, ...

Black holes seem to get all the attention. But what about their mirror twins, white holes? Do they exist? And, if so, where are they? To understand the nature of white holes, first we have to examine ...

Of course, white holes are not a new idea, and were first proposed way back in the 1930s. But what little we know about black holes the same can be doubly said for white holes.