Stephen Hawking is probably the greatest living expert on black holes.
Except, according to him, they don't actually exist.
We know black holes exist. One of them sits in the middle of our galaxy, acting as a gravitational anchor to hold the entire thing together. Without them everything, quite literally, falls apart.
The problem is that black holes mess up our view of the universe. The issue is the "event horizon" - the point in a black hole's gravity well from which even light can't escape. General relativity insists that passing the event horizon itself wouldn't do anything to you.
Unfortunately, quantum mechanics says that there must be a raging inferno just inside the event horizon, the "firewall," which is what creates Hawking radiation - the stuff that makes black holes not quite black.
General relativity says the firewall can't exist. Quantum mechanics says it has to exist.
Hawking's new theory?
There's no such thing as an event horizon. And if there's no event horizon, there's no black hole. Instead, he's talking about an "apparent horizon," within which information becomes completely scrambled...to then escape as that Hawking radiation.
This one's bound to ignite an inferno of its own. And frankly, most of us can't understand it, but it might be one step closer to the unified theory scientists are seeking.
Or one step closer to proving that the unified theory doesn't exist any more than black holes do.
Grey holes, maybe?