Let's hope we never find ourselves in a position where having a way to kill a black hole is important. But physicists, who are always looking out for our best interests, are trying to proactively figure out if it's possible. Obviously, black holes are scary for a bunch of reasons: they eat up everything that gets too close to them, and they have masses up to billions of times more than our Sun. A black hole also generates a lot of radiation that can be deadly to any object near its path.
At one point, scientists believed black holes were indestructible: they were objects that never decreased in size or went away. However, thanks to Stephen Hawking, we learned that as black holes emit radiation, they do eventually evaporate, although it takes a really long time: depending on the mass of the black hole, it can live over 1,000 times the age of the Universe. So is there a way to speed up that process?
Back in the 1980’s, scientists thought that something like a bucket being dropped into a black hole that could suck up some of its radiation might help it evaporate faster. Of course, such a bucket would have to be indestructible and have a rope with zero mass, which is, as we know, pretty much impossible. Such is the problem with theoretical thinking. However, recently, Adam Brown of Stanford University came up with the idea that the one-dimensional sub-atomic strings from string theory could be strong enough to provide the rope for the bucket. But there’s a problem with that, too. Brown said:
"Even they are not strong enough to lower a bucket into the fog of Hawking radiation. The best they can do is guide one extra photon out of the black hole at a time, like water drops travelling along a fishing wire."
So what if we added more strings? Unfortunately, even that wouldn't make much of a difference. Even if the strings could start sucking up the black hole’s material, they still wouldn't be able to do it significantly faster than the black hole would be emitting radiation anyway. Needless to say, black holes are still considered mostly indestructible, at least until they die from their own natural causes.
Via New Scientist