# New Theory Says Black Holes Will Spit Out Their "Singularities" in Time

Pixabay composite

When reporting on Stephen Hawking's posthumous paper theorizing what happens to matter after falling into a black hole,

One of the most problematic parts of a black hole is what's at the center: the supposed home of the hole's singularity. According to current models, a black hole's "singularity" is a giant collection of mass that takes up no space at all, allowing it to have infinite density. This, of course, is a problem for mathematical models trying to describe black holes' behavior: nothing in the universe is truly infinite (at least, not that we know of), so trying to use calculations that involve infinite density run into problems pretty quickly. This has led many scientists to believe that a "singularity" is not what it seems.

To help figure out the nature of singularities, scientists have pioneered new models of gravity that work on very, very small scales, which is usually the domain of quantum physics. One of the more promising models is loop quantum gravity, which hasn't shed much light on black holes until now. However, according to research by scientists Pennsylvania and Louisiana State Universities, applying loop quantum gravity to a singularity has created a new explanation for what happens to all that matter: eventually, the black hole will start spewing it back into the cosmos.

The team claims that, over time, black holes will turn into white holes, which shoot matter out instead of sucking it in. In fact, all the matter the black hole has gobbled up is already in the process of "bouncing" back out, but due to the way the hole warps time, it's happening very, very slowly. Nevertheless, all that matter will eventually come back, say the researchers. This would also mean that a black hole's "singularity" isn't really infinitely dense—we just need a new type of math to understand what it's doing.

*New York Times*writer Dennis Overbye compared Hawking's conclusion to lines from Bruce Springsteen's song "Atlantic City":*Everything dies, baby, that's a fact, but maybe everything that dies someday comes back.*Hawking's idea was that all the "information" contained in a black hole's matter would eventually find its way back into the universe, instead of disappearing when the black hole eventually decayed. Now, a new study claims that all that matter will be back—it'll just take some time.One of the most problematic parts of a black hole is what's at the center: the supposed home of the hole's singularity. According to current models, a black hole's "singularity" is a giant collection of mass that takes up no space at all, allowing it to have infinite density. This, of course, is a problem for mathematical models trying to describe black holes' behavior: nothing in the universe is truly infinite (at least, not that we know of), so trying to use calculations that involve infinite density run into problems pretty quickly. This has led many scientists to believe that a "singularity" is not what it seems.

To help figure out the nature of singularities, scientists have pioneered new models of gravity that work on very, very small scales, which is usually the domain of quantum physics. One of the more promising models is loop quantum gravity, which hasn't shed much light on black holes until now. However, according to research by scientists Pennsylvania and Louisiana State Universities, applying loop quantum gravity to a singularity has created a new explanation for what happens to all that matter: eventually, the black hole will start spewing it back into the cosmos.

The team claims that, over time, black holes will turn into white holes, which shoot matter out instead of sucking it in. In fact, all the matter the black hole has gobbled up is already in the process of "bouncing" back out, but due to the way the hole warps time, it's happening very, very slowly. Nevertheless, all that matter will eventually come back, say the researchers. This would also mean that a black hole's "singularity" isn't really infinitely dense—we just need a new type of math to understand what it's doing.