White holes are objects that only show up in physical theories – none have yet been observed. When a black hole is formed, all the matter and energy that falls into it should go somewhere. The idea is that somewhere else, either in our own universe or another one, another “hole” is created, the opposite of a black hole. This is why it’s called a white hole. It’s theorized that matter and energy that falls into a black hole comes out of a white hole somewhere else.
This is only science fiction at this point, and it may not be correct at all. Steven Hawking discovered something called Hawking Radiation where, in addition to matter falling into black holes, energy is also emitting as the black hole “dies”. This may account for all of the “lost” energy.
Tags: black hole, Hawking Radiation, white holes