Colliding Particles Can Make Black Holes After All 269
cremeglace writes with this excerpt from ScienceNOW:
"You've heard the controversy. Particle physicists predict the world's new highest-energy atom smasher, the Large Hadron Collider (LHC) near Geneva, Switzerland, might create tiny black holes, which they say would be a fantastic discovery. Some doomsayers fear those black holes might gobble up the Earth — physicists say that's impossible — and have petitioned the United Nations to stop the $5.5 billion LHC. Curiously, though, nobody had ever shown that the prevailing theory of gravity, Einstein's theory of general relativity, actually predicts that a black hole can be made this way. Now a computer model shows conclusively for the first time that a particle collision really can make a black hole."
That said, they estimate the required energy for creating a black hole this way to be roughly "a quintillion times higher than the LHC's maximum"; though if one of the theories requiring compact extra dimensions is true, the energy could be lower.
well duh... (Score:3, Insightful)
basically what the TFA is saying is that if you put a lot of energy in a very small spot, you get a black hole...
in other words:
E=mc
+
high mass density = black hole
Nothing to see here, move along
PS: IAAP
Proved conclusively? (Score:4, Insightful)
I don't see how you can prove something conclusively in silico, you put in what you know and you get a distillation of it out. How can you discover* completely new physics when the computer can only start with a potentially incorrect/inaccurate theory and make deterministic calculations based on that input? I mean, you can't get out more than you put in, can you?
Caveat: I can easily accept that collisions of the same energy take place all the time in nature, even if a hole were somehow formed I have far more confidence in Hawking than someone who can scream "Think of the Children!!!" while keeping a straight face.
*There's no reason why you can't put in your theory and come out with a simulation that doesn't resemble how things happen in nature and so begin to disprove a theory. That being said, if CERN could have shown the existence of the Higgs boson using only simulations then they might not have bothered with the LHC.
feh (Score:2, Insightful)
Wow, a computer model says so? Really? (Score:5, Insightful)
Re:Please remember (Score:5, Insightful)
Re:Wow, a computer model says so? Really? (Score:3, Insightful)
For the record, those financial models were perfectly accurate. The data fed into them, however, was stupidly naive and optimistic, which isn't surprising, as the users of the models tweaked the data to get the results they wanted.
Or: Why you should blame the carpenter, not the hammer.
Self-contradictions (Score:5, Insightful)
Gee, what's wrong with this sentence:
Now a computer model shows conclusively...
I'm sure the research modeling is interesting and worthwhile, and it's just the writeup that is idiotic. But y'know *computer* models do not ever show anything *conclusively*. The model is only as good as the assumptions that went into designing it. Those might be good and reasonable guesses, but you are only doing the model because you *haven't* (or can't) observe the actual phenomenon.
Re:Please remember (Score:5, Insightful)
This can be explained very simply.
Shutting down the LHC will not inconvenience these people in the least.
Telling them not to use their SUV to drive to the corner store all the time, or to use it for a one person long distance commute to work will inconvenience them.
Re:Yes (Score:4, Insightful)
Our best theories suggest that if (and it's a big if) a black hole forms, it will evaporate in an instant.
We KNOW that much more powerful collisions occur all the time from cosmic rays. We also know that none of them have destroyed the Earth.
That, in turn, means either such black holes don't form even at much higher energies than we are anywhere near able to produce, or that they decay rapidly just as we theorize, or for some other reason it's nowhere near as bad as we think it could be.
There is no credible theory to even suggest that an LHC produced black hole would be any more problem than those produced naturally by cosmic radiation over the last few billion years.
Re:Ignorance, plain and simple (Score:5, Insightful)
Not true either. At the energies the LHC will collide, not the protons collide, but the constituent quarks and gluons. In fact, when producing very massive objects, it will be the quarks constituting the proton, the so-called valence quarks, that interact; gluons and the so-called sea-quarks are extremely unlikely to reach those energies. So you would end up with some fractional charge. A detail, maybe, but as an LHC physicist, I like things correct :-).
The comparison to the helium atom is wrong too: helium ions, stripped of their electrons, exert quite an electrical pull on their surroundings. But usually they very quickly recombine into neutral helium atoms. Or they have to be accelerated such that their kinetic energy is to large to form a stable atom.
Finally, the comment about the mass of the moving proton is plain wrong too. The only thing that matters to calculate the gravitational pull of the created object is it's rest mass. The relativistic mass that is being referred depends on the frame of reference (and is therefore an uninteresting quantity we never really work with). Imagine the force being dependent on the frame of reference...
That all being said, I agree the whole apocalyptic story is plain stupid, but as scientists we cannot afford using wrong arguments. And we need better PR maybe, because a 1/quintillion (or whatever probability limit set) is maybe not zero, but should be rounded down as such for public dissemination.
Re:Ignorance, plain and simple (Score:3, Insightful)
I take your point about the quarks. The point about mass though is that there is a privileged frame in this context, namely the rest frame of the eventual black hole. If you are in some other frame you will see a HIGHER mass, since you will see a moving black hole at the end of the day. Another way of seeing it is that the energy put into accelerating the protons ends up in the rest mass of the black hole.
Re:Please remember (Score:4, Insightful)
Re:No harm, no foul (Score:5, Insightful)
I am more likely to trust a peer review from the guys at the LHC, when they talk about their research, than the IPCC folks, when they talk about theirs.
Both cause me puzzlement, since how can a (necessarily imperfect and incomplete) computer model conclusively prove anything???
Either the scientists have too much faith in their own genius, or the Science Now "journalist" doesn't know how to critically think.
few atom balck holes evaporate instantly (Score:3, Insightful)
(1) First is lifetime would be shorter than time it would take to interact with anything else.
(2) Its event horizon would be so small as to keep from interacting with most matter before it evaporated.
(3) Particles dont interact gravitationally in practice. Other atomic forces are 38 or more magnitudes larger.
I wouldnt be surprised if existing colliders and cosmic rays routinely make black holes. We just dont see these very tiny ones.