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New Heavy Ion Collider could "destroy the earth"

Posted by Hemos on from the honey-i-destroyed-the-earth dept.

Sith Lord Jesus writes "According to an article in the London Sunday Times, a new nuclear accelerator designed to recreate the Big Bang might possibly--*possibly*--cause the earth to "disappear in the twinkling of an eye." Oops. " This reminds me of the some the fears that the folks in the Manhatten Project had-almost zero chance of anything occuring, but the notion of creating a black hole on the surface of the Earth is a strangely appealing one, from a sheer comedic value POV.

2 of 413 comments (clear)

  1. The problem is that they're scientists by Anonymous Coward · · Score: 5

    So they won't say it "can't" happen, since you can't say that about anything. If you solve the quantum mechanics of picking my nose there is a nonzero probability that I will create Dark Matter which will cause the subsequent distintigration of my nose, me, and the alpha quadrant. That is what our probibalistic universe means. There is just about a nonzero probability of anything.

    Back in the 70s when the first recombinant DNA experiments were taking place, there was a public outcry, mainly a result of politicians stirring up people for political reasons. They dragged a bunch of biologists into court and asked them the probability of creating dangerous organisms, as some scientists had suggested. Of course, the biologists who were about to do the experiments had carefully researched this possibility and come to the conclusion that it was extraordinary- but of course, not nonzero. When they testified, they were repeatedly asked if such a thing could never happen. They had to answer no, of course not, there is always a probability of anything happening.

    Well, the experiments were banned for several years. No one in the world had any problems with inadvertant creation of dangerous organisms, and now recombinant dna experiements are commenplace. But think of the progress that was lost!

    Remember that scientists are people too, and don't want the earth to collapse any more than you do. Saying that something has a small probability is about the safest assurance you can hope for, at least from a real scientist. Articles like this that attempt to use scare-mongering to whip up readership, at the expense of science, are very dangerous for everyone.

  2. Re:cosmic ray energies by Neil+Rubin · · Score: 5
    Actually, a very small number of cosmic rays have been observed above 10^8 TeV (10^20 eV). A total of about 9 events have been observed, by several different experiments, with energies above the so-called GKZ cutoff of 2.5*10^7 TeV. This number of events corresponds to a few cosmic rays above that energy per square kilometer of the Earth's atmosphere per century, or roughly 10^16 of these events in the history of the Earth, if my math is correct.

    The question of exactly where all of these insanely high energy particle come from is a deep mystery. Proposed answers include: Gamma Ray Bursts, Active Galactic Nuclei, interactions involving Magnetic Monopoles or Cosmic Strings, the decays of super-massive relics from the big bang, etc. For more info on these rare events, see the Pierre Auger Observatory website at www.auger.org.

    Now 2.5*10^7 TeV sounds like an incredible ammount of energy compared to the .1 TeV/nucleon of RHIC, but since the cosmic rays are hitting essentially stationary nuclei in the Earth's atmosphere as opposed to the head-on collisions of RHIC, most of the energy just goes into the kinetic energy of the collision debris rather than into producing interesting physics. The relevant figure is the center of mass energy of the cosmic ray and target nucleus system. It turns out that this is equal to sqrt(2*m*E), where m is the mass of the target and E is the mass of the cosmic ray. Supposing that the target is a Nitrogen nucleus, we get sqrt(2*.014 TeV*2.5*10^7 TeV) or roughly 10^6 TeV. The corresponding figure for RHIC 2*(200 nucleons)*(100 GeV/nucleon)=4*10^4 TeV. The cosmic ray events win, but only by a bit more than an order of magnitude. (Note that this is all very much "back of the napkin" calculation, and may not be exactly right, but it's close.)

    That was fun, but what does it all mean? Well, from the RHIC documentation, I figure that RHIC will have roughly 10^15 bunch crossings in each full year of collision running. Assuming that there is less than one collision per beam crossing (it makes it much easier to figure out what's going on in each collision), RHIC will produce an order of magnitude fewer collisions, with an order of magnitude lower energy density than these cosmic rays that bombard the Earth naturally. While a more careful analysis may change some of these numbers by a bit, it seems pretty unlikely that RHIC will destroy the Earth, when all of these cosmic ray collisions obviously haven't.