How Do You Kill a Black Hole?




Universe Today Video show

Summary: Black holes want to absorb all matter and energy in the Universe. It's just a matter of time. So what can we do to fight back? What superweapons have been devised to destroy black holes? Black holes are the natural enemies of all spacefaring races. With their bottomless capacity to consume all light and matter, it’s just a few septillion years before all things in the Universe have found their way into the cavernous maw of a black hole, crushed into the infinitely dense singularity. If Star Trek has taught us anything, it’s that it’s mankind’s imperative to survive against all odds. So will we take this lying down? Heck no! Will we strike first and destroy the black holes before they destroy us? Heck yes! But how? How could you kill a black hole? This... gets a little tricky. For a black hole, any matter entering the event horizon is added to the mass. Shoot bullets at a black hole, and you just make a slightly more massive, slightly more dangerous black hole. Detonate a nuclear bomb inside the event horizon, and you only make the black hole more massive. Fire your forward phasers at the black hole, and that’ll still make it even more massive. Swap those bullets in for lasers and black holes don’t care. Within the event horizon, energy and matter are one, and those very same black holes can convert that energy into mass. So all your projectiles and energy weapons inevitably just make it more dangerous. What if we crashed a star into it? Would that fill it up, or burn it out? Nope. It would just gobble that star up, and go on with its business. If we smashed another black hole into it? Would that tear it apart? The cause is also the cure? Not even maybe. As soon as black holes get within each other’s event horizons, they’ll just merge into a more massive, and even nastier, meaner black hole. Number 1, it’s time to bring out the big guns. Reverse the particle flow, flood the dilithium chamber with exotic particles and route it through the main deflector dish, and construct your own black hole out of antimatter. Then kamikaze this new antimatter black hole right into a the black hole you want to destroy. Would that do it? Would that solve our problem? As you probably know, when you crash matter into antimatter, you get an explosion of pure energy. It’s the most perfect energy weapon we can envision. Unsurprisingly, this brings its own set of complications. It’s not entirely clear you’ve still have antimatter in your antimatter black hole. It’s possibly been converted into a regular flavour black hole. Still, if you *could* crash an antimatter and regular matter black hole together, you would get an incomprehensible explosion. Converting that entire dense and gigantic mass into pure energy, as calculated by Einstein. As soon as you did, all that energy would be immediately converted... into more black hole. Nothing, not even light itself can escape a black hole. That includes all your magnificent explosion energy from your antimatter impact. You wouldn't even see it happen. You’d just end up with a black hole with twice the mass. And that might be just what it wants. As we learned in a previous episode, we can extract angular momentum from a black hole. By dropping material into the event horizon, we can remove energy and slow its rotation. We can even bring it to a stop. So we can slow down its spin, but that won’t make it go away. So, is that it, are we out of options? Good news, we have one last strategy, and it’s so crazy it just might work. According to Stephen Hawking, black holes can actually evaporate over enormous periods of time. Virtual pairs of particles are constantly popping into existence all around us. Then they recombine in a flash and disappear from the Universe. When one of these particle pairs appears right on the edge of a black hole, one particle falls into the black hole, and the other is free to fly off into space. And here’s the amazing thing.