Why don’t black holes swallow all of space?

Science Alert
Black holes are great at sucking up matter. So great, in fact, that not even light can escape their grasp (hence the name).
But given their talent for consumption, why don’t black holes just keep expanding and expanding and simply swallow the Universe? Now, one of the world’s top physicists has come up with a new explanation.
Conveniently, the idea could also unite the two biggest theories in all of physics.
The researcher behind this latest explanation is none other than Stanford University physicist Leonard Susskind, also known as one of the fathers of string theory.
He recently gave his two cents on the paradox in a series of papers, which basically suggest that black holes expand by increasing in complexity inwardly – a feature we just don’t see connected while watching from afar.
In other words, they expand in, not out.
Weirder still, this hypothesis might have a parallel in the expansion of our own Universe, which also seems to be growing in a counterintuitive way.
“I think it’s a very, very interesting question whether the cosmological growth of space is connected to the growth of some kind of complexity,” Susskind was quoted in The Atlantic.
“And whether the cosmic clock, the evolution of the universe, is connected with the evolution of complexity.
There, I don’t know the answer.”
Susskind might be speculating on the Universe’s evolution, but his thoughts on why black holes grow in more than they do out is worth unpacking.
To be clear though, for now this work has only been published on the pre-print site arXiv.org, so it’s yet to be peer reviewed. That means we need to take it with a big grain of salt for now. On top of that, this type of research is, by its very nature, theoretical.
But there are some pretty cool idea in here worth unpacking. To do that, we need to go back to basics for a moment. So … hang tight.
For the uninitiated, black holes are dense masses that distort space to the extent that even light (read: information) lacks the escape velocity required to make an exit.
The first solid theoretical underpinnings for such an object emerged naturally out of the mathematics behind Einstein’s general relativity back in 1915. Since then physical objects matching those predictions have been spotted, often hanging around the centre of galaxies.
A common analogy is to imagine the dimensions of space plus time as a smooth rubber sheet. Much as a heavy object dimples the rubber sheet, mass distorts the geometry of spacetime.