Could The Theoretical White Hole Actually Exist?
You may know that a black hole is said to suck matter into a single point of entry. But what if you reversed that formula? A white hole is a theoretical black hole in reverse. But could it actually exist?
White Holes Sound Just As Terrifying As Black Holes
White holes are the unicorns of the universe. They probably don't exist, but they're a fantastical thrill ride to think about. These things are the theoretical opposite of black holes, thought to expel matter from a single point with no entryway. Yes, think about a point in space that is just constantly spewing space junk that literally comes out of nowhere. So why do they (probably) not exist? There would need to be not a single speck of matter within the event horizon for a white hole to form—which isn't very likely, from what we know. White holes break the second law of thermodynamics, because where black holes increase entropy, white holes would decrease entropy.
Of Course Einstein Is Involved
What's a crazy-cool physics thing without mention of Albert Einstein? One theory that supports the possibility of white holes comes from Einstein's theory of relativity. As PBS reports, "One possibility involves a spinning black hole. According to Einstein's general theory of relativity, the rotation smears the singularity into a ring, making it possible in theory to travel through the swirling black hole without being crushed. General relativity's equations suggest that someone falling into such a black hole could fall through a tunnel in space-time called a wormhole and emerge from a white hole that spits its contents into a different region of space or period of time."
Don't get your hopes up. Mathematical solutions for white holes exist, but "they're not realistic," Andrew Hamilton, an astrophysicist at the University of Colorado at Boulder. PBS explains, "That is because they describe universes that contain only black holes, white holes and wormholes—no matter, radiation or energy. Indeed, previous research, including Hamilton's, suggests that anything that falls into a spinning black hole will essentially plug up the wormhole, preventing the formation of a passage to a white hole."