Are the “Black Holes” that CERN claims to make, (or will make after the Large Hadron Collider is fixed) the same black holes that are in the center of Galaxies? They claim that these tiny holes won’t suck up the World, our Planet, Solar System, etc. but why won’t they? Seems to me that a Black Hole is what it is, a gravity abortion that will suck up everything within its area in microseconds, by definition. And eventually me! Can it? Will it? If not, why won’t it? Will I wake up someday flying toward France and CERN to be gobbled up by one of these things? (It would be kinda a cool way to go, though!)
The mind boggles……
Hawking radiation is the answer.
I’m not even going to try to explain it, but suffice it to say that black holes evaporate in finite time. For the giant black holes at the cores of galaxies and resulting from collapsing massive stars, the time span to evaporation is on the order of 10[sup]n[/sup] years – the number climbing rapidly with increasing mass. For the infitesimally small black holes that CERN might produce, though, the numbers would be on the order of 10[sup]-n[/sup] seconds – aand the evaporation would just give off what energy was put in.
As world-ending disasters go, this is slightly lower on the probability scale than fire-breathing mutant iguanas with a taste for Japanese cities.
There have been about 10[sup]n[/sup] previous threads on this, if you want to search.
Well, that’s not really what a black hole is, by definition.
Phil Plait:Why do black holes have such strong gravity?
The gravity of a black hole depends on its mass, so the heaviest black hole a scientist can create still has only the amount of gravity you’d expect an energetic subatomic particle to be.
The only way a black hole of that size could grow would be to accidentally collide with some other thing and absorb it, and it would have to keep accidentally running into things faster than its rate of evaporation. That’s extremely unlikely to happen. In fact, I wonder if it would be possible to keep it alive even if we wanted to.
It should also be noted that the LHC is not expected to produce black holes, and producing black holes is not the purpose for which it was built. It’s conceivable that we might get very lucky and discover that the laws of physics are such that it can produce black holes, but if that happens, it’s icing on the cake. The purpose for which the LHC was built is to detect the Higgs boson.
To elaborate on this, if you were to suddenly turn the Sun into a black hole, keeping its mass the same, then all of the planets would continue to orbit it in exactly the same way they do now. In practical terms, the only way in which a black hole is different from any other mass is that gravity gets stronger as you get closer to a mass, and you can get closer to a black hole than you can to anything else: If you try to get closer than about 700,000 km to the center of the Sun, you’ll find that you end up colliding with the surface, but for a solar-mass black hole, you could get down to about 3 km without colliding with anything.
Finally, whatever the LHC might end up doing, black holes or otherwise, we know that it can’t possibly destroy the Earth. Cosmic rays with energies far greater than anything the LHC can produce strike the Earth on a regular basis, and none of them has ever destroyed the Earth. The only reason we’re building the LHC instead of just studying the cosmic rays is that you can never know when or where a cosmic ray is going to hit, so they’re harder to study.
Even if MBHs were actually created, and for some miraculous reason didn’t instantaneously evaporate via Hawking radiation, what you’d have is a tiny little thing with a mass on the order of a few TeV, equivalent to the mass of a few thousand protons or roughly 10[sup]-23[/sup] kg, about one billionth of a billionth of the mass of a grain of sand. What can a black hole of this mass do to you? Well, pretty much what anything of this mass can do to you: not very much at all. If you’re very unlucky, it might hit a nucleon while passing through you – Backreaction has a nice, semi-classical estimate showing that a black hole going through solid iron can be expected to hit a nucleon about every 200km. What happens then, though, is pretty much anyone’s guess, and the most likely answer is probably nothing – even a proton, to a black hole of this size, is pretty much just a dilute cloud of quarks and gluons. Still, worst comes to worst, you’re out of a proton (or neutron) you won’t miss.