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Earth Science

Black Holes From the LHC Could Last For Minutes 672

KentuckyFC writes "There is absolutely, positively, definitely no chance of the LHC destroying the planet (or this way either) when it eventually switches on some time later this year. And yet a few niggling doubts are persuading some scientists to run through their figures again. One potential method of destruction is that the LHC will create tiny black holes that could swallow everything in their path, including the planet. Various scientists have said this will not happen because the black holes would decay before they could do any damage. But physicists who have re-run the calculations now say that the mini black holes produced by the LHC could last for seconds, possibly minutes. Of course, the real question is whether they decay faster than they can grow. The new calculations suggest that the decay mechanism should win over and that the catastrophic growth of a black hole from the LHC 'does not seem possible' (abstract). But shouldn't we require better assurance than that?"
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Black Holes From the LHC Could Last For Minutes

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  • by gatkinso ( 15975 ) on Friday January 23, 2009 @12:08PM (#26575343)

    >> proud motherland of the apes, chimpanzees, macaques, baboons

    Not to mention humans.

    PS Crack a dictionary, read the definition of "niggle." But then again a mind that operates at your level is easily distracted by shiny objects and rhyming words, I suppose.

  • by Smidge207 ( 1278042 ) on Friday January 23, 2009 @12:08PM (#26575359) Journal

    "haven't accounted for 96% of the energy and mass of the universe in their current model."

    BUT...they also haven't accounted for all possible group particle mergers and interactions in the LHC. Unlike nature, in a particle accelerator they have groups of high energy particles moving in close proximity. In nature, we have lone high energy particles. We don't know what we can create in group collision mergers of high energy particles and even though these are rare compared with single particle interactions, they can still occur. Even if a black hole like particle was briefly formed and then hit by another particle or two or twenty, then what?. The point is, we simply don't know whats possible, but its very likely to be a different situation than simply a lone particle able to break down. If a group collision merger occured in nature, it would most likely be very rarely occuring, but it could be enough to help account for some fraction of the mass of the universe. We simply don't know, but we do know that in a particle accelerator, its going to happen a lot more often than in nature and we don't know what kinds of reactions group high energy mergers could cause.

    While its (mostly) safe to assume single high energy particles are not going to be a problem, as they happen relatively often in nature, we cannot say the same for multiple collsion mergers and all possible interactions of multiple particles, as we simply do not know for sure. The current various theories are not proof its safe and the fact we cannot account for so much energy and mass in the universe is a very good reason to suspect our theories are wrong.

    Also the fact they are building the LHC is proof in itself that they build it to learn, so they don't currently know for sure. Also for all their planning, even that magnet failure showed their theories and multi-million dollar design plans about how the machine should function can still go wrong. Humans make mistakes. Thats fine, we all accept that, but making a mistake with the LHC could potentially be the most serious mistake in human history.

    What concerns me is their intense desire to learn is going to bias their judgment. (I know my desire to learn has biased my judgment from time to time), but this is the most important experiment in human history, so its vital it doesn't go wrong in any way, or it could be the last experiment.


  • by tnk1 ( 899206 ) on Friday January 23, 2009 @12:09PM (#26575365)

    There is absolutely, positively, definitely no chance of the LHC destroying the planet (or this way either) when it eventually switches on some time later this year. ...

    But physicists who have re-run the calculations now say that the mini black holes produced by the LHC could last for seconds, possibly minutes. Of course, the real question is whether they decay faster than they can grow.

    Well its good to know that despite their uncertainty about the the data, they are absolutely certain of their conclusions.

  • Well... (Score:5, Insightful)

    by AltGrendel ( 175092 ) <ag-slashdot&exit0,us> on Friday January 23, 2009 @12:09PM (#26575369) Homepage
    ...there's one sure way to find out.

    Fire it up, boys!
  • cosmic rays (Score:5, Insightful)

    by cats-paw ( 34890 ) on Friday January 23, 2009 @12:09PM (#26575371) Homepage

    I thought that this entire line of doomerism had been dispensed with thanks to cosmic rays.

    Since cosmic rays are striking the earth all the time, and a decent percentage of them have a much higher energy level than anything the LHC can produce, we should have already seen such a phenomena.


  • by Mindwarp ( 15738 ) on Friday January 23, 2009 @12:10PM (#26575393) Homepage Journal
    The Sun in conjunction with the Earth's atmosphere has been colliding particles with WAY higher energies that the LHC could ever manage for billions of years now. As far as I know we've not been consumed by a mini black hole yet.
  • already happens (Score:2, Insightful)

    by Anonymous Coward on Friday January 23, 2009 @12:11PM (#26575407)

    Anything that could happen due to the LHC, already happens daily. The collisions in the LHC aren't as energetic as collisions that occur in the upper atmosphere from cosmic rays, etc ALL OF THE TIME. The reason to build the LHC and other accelerators is that it's kind of a pain in the ass to mount detectors on balloons and *hope* that your detector intercepts some of said cosmic rays...

  • Re:Assurances (Score:3, Insightful)

    by jespley ( 1006115 ) on Friday January 23, 2009 @12:25PM (#26575637)
    To put some numbers on this, the LHC [] will produce protons with 10^14 eV of energy. At that energy, we expect [] more than 1 per m^2 per year. I haven't seen any black holes recently in the square meters of the Earth's surface I routinely interact with. You? I wish the numerical illiterate would stop scare-mongering.
  • by dazedNconfuzed ( 154242 ) on Friday January 23, 2009 @12:27PM (#26575675)

    A black hole is just the gravity well of a given mass compressed into a sufficiently small space. In this case, the given mass is miniscule, so very little (practically nothing, hence the "evaporation" issue) will be drawn to it.

    You have more to worry about from the gravitational pull of your shoes.

  • Re:cosmic rays (Score:5, Insightful)

    by Goldsmith ( 561202 ) on Friday January 23, 2009 @12:45PM (#26575999)

    There is no need for comments on this article other than the parent. In fact, this article should just be put into idle.

    As a physicist, this whole thing has been an embarrassing reminder of just how bad physicists are at public relations and the failure of many people to think logically. I'm not the biggest fan of LHC, but I'd like to see some intelligent criticism out there (Is this really where we should be putting our smartest scientists? Are particle accelerators the best way to do this measurement?), not this junk.

  • by chunkyq ( 995864 ) on Friday January 23, 2009 @12:46PM (#26576037)
    The parent post is also a fine example of making grand claims about advanced science without providing a single reference.
  • by syphax ( 189065 ) on Friday January 23, 2009 @12:52PM (#26576175) Journal

    I was so not in a joking mood at the end of that experience-

  • by AndersOSU ( 873247 ) on Friday January 23, 2009 @12:52PM (#26576189)

    I would think you'd need a quantum theory of gravity to express the effects time dilation in or near a black hole of this scale.

  • Re:cosmic rays (Score:3, Insightful)

    by 0xABADC0DA ( 867955 ) on Friday January 23, 2009 @01:03PM (#26576433)

    What I object to is exactly that kind of reasoning.

    I'm not a particle physicist, so I don't know the math and formulas and such, but what I do know for sure is that they are incomplete. Our physics doesn't completely account for everything in the universe so there is no way you can say that just because high energy particles have been hitting the planet for eons that LHC can't destroy the planet. For instance, when was the last time a high energy particle hit the earth near a torus of high energy particles and huge magnetic fields? Oh, that hasn't ever happened in the history of the planet you say? Interesting.

    These physicists are people, like everybody else, and they make the same kinds of mistakes. I can't count the number of times debugging a program crash that I've said or others have said that the cause can't possibly be X because we know for a 'fact' that the code is correct, only to have it turn out to be exactly that. That's the same scenario, only seen from the opposite direction. People make bad decisions and especially when they are invested in that decision (like, it being the culmination of 40+ years of your work...).

  • by Goaway ( 82658 ) on Friday January 23, 2009 @01:11PM (#26576583) Homepage

    You shouldn't be so quick to take everything you read on Wikipedia at face value, you know.

    What happened was, the possibility was considered, and quickly calculated to be impossible, but somebody still entered it into the betting pool as a very dark joke, same as the "destruction of New Mexico" entry. Both were known to be impossible.

  • Re:cosmic rays (Score:5, Insightful)

    by Thiez ( 1281866 ) on Friday January 23, 2009 @01:26PM (#26576859)

    > Is this really where we should be putting our smartest scientists?

    What gives us the right to decide where to 'put' 'our' smartest scientists? They belong to themselves, right? It is their choice what to do with their brains (cure cancer or get drunk or work at the LHC).

    If you insist on asking a question I guess you could ask 'Do we really want to fund the LHC?'.

  • Re:Bogus (Score:4, Insightful)

    by LeDopore ( 898286 ) on Friday January 23, 2009 @01:56PM (#26577463) Homepage Journal

    First things first: I'm not an alarmist, and I don't think the LHC will blow up the Earth.

    That said, I'd like to point out that not nearly all of that 10^20 eV is available to make new particles/black holes in the center of mass frame of the collision. Since all the collision products will have to have a ton of momentum in the direction that the cosmic ray was originally traveling, the available energy for creating new, potentially dangerous particles scales with the square root of the product of the energies (see [] for a pretty good explanation of where this square root dependency comes from).

    In contrast, the LHC will collide two particles in the TeV range head-on, which means the collisions have more of a chance of creating an "exotic" than even a 10^20 eV particle hitting stationary atmosphere.

    However, I bet two high-energy cosmic rays each with energy > 10^14eV sometimes collide with *each other*, and that collision would have more available energy than the LHC collisions. The big question is how often does this happen? If collisions like these happen at a slow enough rate, I could imagine that the LHC might put Earth into unexplored territory in terms of numbers of collisions with ~10^14eV of available (i.e. not constrained to producing products with high momentum) energy.

    I trust that the physicists have worked out the rates of these head-on, two-cosmic-ray collisions. Otherwise they would have no right saying that cosmic ray history shows that the LHC will be safe. Still, the only defense based on cosmic rays I've heard has been talking about cosmic rays hitting atmosphere, which isn't valid. Does anyone have a good link to a website analyzing the frequency of head-on two-cosmic-ray collisions?

  • by Hordeking ( 1237940 ) on Friday January 23, 2009 @02:03PM (#26577591)

    Here's an interesting thought.

    1kg black hole would have a cross sectional area far smaller than that of an atomic nucleus (or electron, or even the elementary particles), and gravity will be too small to do any attractions.

    How would electroweak and strong forces apply to this? I can certainly theorize that since strong forces act over the femtometer scale, and the schw. radius is smaller than that, the particle would certainly be able to get within strong range. And the strong force of 1kg worth of mass acting on an atom would have to be absolutely astronomical.

    A second thought would be what would happen if the black hole collides with the particle. Assuming the event horizon can't envelop the whole particle, and the particle is indivisible (unlike stars, gases, planets, and other macroscopic objects), what happens? Do we have a particle with a hole in it, a particle that goes completely into the hole, or do they not interact?

  • Re:It's Crazy (Score:3, Insightful)

    by GeneralEmergency ( 240687 ) on Friday January 23, 2009 @02:15PM (#26577827) Journal

    The vacuum between that girl's ears must be vastly superior to the LHC's.

    She must be studied.


  • Re:Bogus (Score:3, Insightful)

    by Eudial ( 590661 ) on Friday January 23, 2009 @03:01PM (#26578631)

    Really a footnote, but a very high-energy collision with a stationary object like you describe would be more worrisome, since whatever exotic matter would be created could possibly move at relativistic speeds, increasing their half life by the Lorentz factor.

  • Re:Bogus (Score:3, Insightful)

    by Eudial ( 590661 ) on Friday January 23, 2009 @06:38PM (#26582279)

    What's a low-momentum, high-energy particle, 50% the speed of light rather than 5 nines the speed of light?

    Non-relativistic particles shouldn't be impossible. If the momenta of both colliding particles are equal and opposite, the sum momenta of the resulting "debris" will be 0. Though, even at speeds like 95% of the speed of light, the Lorentz factor is pretty negligible when it comes to extending the life of the particles. It's measurable, but it won't make them survive for hours and days when they were supposed to live for nanoseconds.

  • Answer: no (Score:3, Insightful)

    by toriver ( 11308 ) on Friday January 23, 2009 @07:49PM (#26583171)

    But shouldn't we require better assurance than that?

    The doomsayers have grabbed onto this idea of horrible black holes, but the proof that these will even appear are from the same scientists that try to convince them that any black holes, in the unlikely case they will appear, will be harmless. "Assurance" seems to be a requirement directed at only one side of the fence while the other is free to do its unscientific fantasizing without any need to provide actual proof.

    I mean after they have proven that the Earth will not be swallowed by a black hole when they perform the experiments, what next?

    Prove that a dimensional gate will not open, letting in Yog-Sothoth from the great beyond.

    Prove that the collision will not exterminate the (ultra-rare) unicorns.

    Prove that the collider doesn't employ Goa'uld technology.

    It never ends.

    Meanwhile, said doomsayers carry mobile phones in their pockets even though it hasn't been proven that the radiation doesn't cause infertility and cancer. They drive cars even though the probability of getting killed that way is many orders of maginitude higher than the black hole forming hypothesis...

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