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Man-Made Black Holes Looming?
camusflage writes: "The New York Times has a story that some physicists think it might be possible to make black holes at the under construction Large Hadron Collider at CERN, slated to come online in 2006. Trying to allay concerns about a man-made black hole blipping us out of existence, they say "The same calculations ... predict that around 100 such black holes a year are `organically' and apparently safely produced in the earth's atmosphere in cosmic ray collisions." As long as we can keep critters from building nests in the singularity, we should be okay."
We all know Black holes suck..
As everyone knows, gravity is the weakest of all the fundamental forces by a very very long way, something like 40 orders of magnitude weaker than the weakest of the nuclear forces. I remember reading an article here long ago (can't find it and put a link to it because Slashdot search is down...grr) that talked about some speculation that gravity is so weak because the universe has more dimensions than the four that we see (this is also a prediction of superstring theory), and while the other three forces are only capable of propagating there, gravity is able to propagate through these extra dimensions, making it seem weaker. These dimensions are supposed to be curled up small so we don't normally notice them, so one of the implications of this theory is that the value of the universal gravitational "constant" should shoot up dramatically when you try to measure it at smaller scales; the smallest scale at which gravity has been measured so far is on the order of centimeters only. Another implication is that it should be possible to create low mass black holes with less energy than the weakness of gravity as we know it predicts. So if these scientists are successful in making such small black holes, it could go a long way to validating this theory.
Qu'on me donne six lignes écrites de la main du plus honnête homme, j'y trouverai de quoi le faire pendre.
Everybody already knows black holes spontaneously appear. Here's an experiment to prove it.
Place two matching socks in a washer machine. turn the washer machine on, wait for it to finish. Remove the single sock. Voila. Black holes.
Now place that single sock into the drier. Turn it on, wait for it to finish. Remove one entirely different sock, which you have never owned. Kazow. Alternate Dimensions.
The field of pairingsocks physics solved the Black Hole question years before the cosmologists or those silly particle physicists. This article is old news.
The simple fact is that nature still does better at creating high energy particles than anything we can do in the lab. The reason a 100 blackholes might be created in the atomsphere is because cosmic rays are still more powerful than accelerators. In fact rare extremely powerful cosmic rays, believed to be extra-galatic in origin, are still several orders of magnitude beyond what we can make.
Since these high energy cosmic rays will have the same types of collisions as they want to produce in the lab, you would expect them to produce black holes if that is possible. Any such black holes that might be produced obviously haven't destroyed the Earth thus far, so these energies are probably safe to use in a lab. Of course this may just mean that they never actually create black holes.
Regarding your other issue, nuetrinos. The reason they didn't come out right is because Super Kamiokande and the other 1st generation experiments could only detect electron and muon nuetrinos. The next generation results, which came out in the last two years, show that when you account for the number of tao nuetrinos, the total flux from the sun turns out to be right where it should be according to the theories for what goes on in stellar fusion.
The surprise here is that nuetrinos of one type can apparently turn into another type. We knew from theory how many electron nuetrinos to expect but they were hidden by changing into the other two varieties. Thus the appearance of low nuetrino counts. Flavor mixing, as it's called, is exactly what is predicted and required if nuetrinos have a non-zero mass. So we simple have to accept that nuetrinos have small but non-zero mass and figure out how this revises the "Standard Model" of particle physics.
The ultimate Darwin Award
Don't worry about posting a pun. When the story is about black holes, there's no escaping it.
They better not try to put their pet black hole in a bag of holding.
As another poster pointed out - if this kind of black hole creation were going to cause any problems, it already would have. If these high-energy particles they will be making will produce black holes, then there are about 100 black holes produced per year as a result of cosmic radiation - and they haven't been detected yet, so obviously they have a pretty small effect, and there's nothing to worry about.
People often worry excessively about Nuclear phenomena. This is, as far as I can tell, because very few people actually know what natural levels are.
There is a natural background level of radiation which varies by 10% from place to place. Nuclear facilities are typically permitted to increase the level by 1%. By contrast, international flights usually involve triple the normal background level of radiation - it's cosmic radiation that doesn't reach the ground.
In one mole of carbon - 12g, about what you might find in a fruit - you get about 100 decays a second; this is from the tiny fraction of naturally produced 14C. How radioactive do you think you are? (grin)
Rachel Butt
Nuclear Physics PhD student.
Fast forward a few years, scientists make a black hole. Why doesnt it destroy the earth?
1) The black hole weighs no more than the particles slammed together to make it. It has essentially zero pull on anything. A grain of salt would make an incredibly more effective attractor.
So you say, yes, but the black hole will persist and continue to grow in mass by swallowing more and more particles.
But the scientists in the Times article say the black hole will "evaporate".
The following paragraph, from this page, states it well:
Since the 1970s, it has been known that black holes are not completely black. In fact, they emit very low-energy radiation called Hawking radiation. The lower the mass of a black hole, the higher the energy of the emitted Hawking radiation. As a black hole radiates, its mass decreases, and it starts emitting more and more radiation, causing it to evaporate more and more rapidly. Eventually, it shrinks to around the Planck mass, the point at which its DeBroglie wavelength is equal to the Schwarzschild radius. At this point, we no longer know what happens, since to describe physics at the Planck scale requires a theory of quantum gravity.