Black hole in LHC?

  1. Hi,
    I have no academic grounding in advanced physics, but I have read a lot of the popular books on physics, and am generally interested in it. (In a couple of years that's probably what I'll learn in college).
    Anyway, there are people who are afraid that when the LHC goes on this summer we might accidentally create a black hole and destroy the planet.
    I don't have the mathematics to back this up, but:
    If we do create a singularity in CERN we will be inside the event horizon, and so close to the singularity itself that we will feel the effects of infinite time dilation. So if we did create a black hole, we won't know about it because time has ceased to have a meaning for us.
    Does that make any sense?
     
  2. jcsd
  3. We have been discussing this many times, and you can find many such discussions. [thread=236225]This one for instance[/thread]...

    Physicists know what they are doing, and the LHC will not destroy the Earth.
    Otherwise claims are simple displays of scientific misunderstandings. Those claims simply do not hold water under inspection.

    Most important for us physicists, is that this is a communication problem. We have interesting things to do in LHC. Public interest in this fake problem is very disappointing, since it distracts attention from the real points of LHC.
    No it does not. Sorry. This is qualitatively wrong, not even to mention quantitative thinking.

    If you want to study physics, may I advise you to quit reading popular books, and start reading the real stuff ?
    I mean, at your level, start building a concrete knowledge of physics instead of reading about physics.
     
    Last edited: May 26, 2008
  4. I for one am not worried about the black hole, I think it would be pretty cool. It would be even more cool if the time dilation thing made sense.
    Could you please explain (without being condescending) why this is qualitatively and quantitatively wrong.
    What do you mean "the real stuff"?
    I've read two of Stephen Hawkings' books, (didn't like them much), Brian Greene's "The elegant univers" (3 times), George Gamow's "Mister Thompson" (the original and the newer one with the right physics), "Big Bang" by Simon Singh and a few others I've forgotten.
     
  5. Sorry if I appear condescending to you. I am just really tired of discussing about BH in LHC. As I mentionned to you, the BH stuff is anecdotal compared to what LHC is really about.

    It should not be my task to show to you why "If we do create a singularity in CERN we will be inside the event horizon..." is just wrong. I can not guess where your calculation went wrong if you do not let us know any element of this calculation. For one thing, what is the BH mass that you use ? The BH mass will allow us to estimate the horizon radius. You should find something insanely tiny, much smaller than typical atomic sizes.
     
  6. Sorry about that. I'm interested in the LHC not because of th BHs but for the REAL experiments going on there. I thought that it would also be cool if we got a BH and didn't know about it.
    This was a supposed to be a funny question, nobody was supposed to take it seriously. But seeing how you do not have a sense of humor I humbly beg your apology and retract my question.

    If you do know any physicists with a sense of humor, show this to them.

    Good day to you sir.
     
  7. malawi_glenn

    malawi_glenn 4,727
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    Homework Helper

    How could you come to that statement of yours without having any mathematics to back it up? That is a riddle for me..

    And if you think the books you have read is "real stuff" then welcome to reality, try this one for instance: "A First Course in General Relativity" by Bernard F. Schutz
     
  8. Well, we probably do not have the same sens of humour :bugeye:
    I myself know quite a few physicists with quite a good sens of humour ! :tongue2:

    edit
    Besides, this is the physics discussion forum, not the science-joke forum (which exists somewhere else).
     
  9. Assuming this kind of physics is right, then you have virtual BHs popping in and out of existence around your own self in the vacuum, but you can't know it. Now, that is funny to me.
     
  10. You mean BS, right?
    Anyway, being young (21) I still think the universe is governed by cool.
    If it's cool it works, if it isn't, it doesn't.
    How cool is that?
     
  11. cristo

    cristo 8,394
    Staff Emeritus
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    Precisely!

    Max: Where in your post do you say that this is a joke? If it posted in the technical forum, then we take it to be a serious physics question. If you wish to joke around, then please use general discussion.
     
  12. LHC Hazards

    I have seen endless debate regarding the risk of Black Hole production at the LHC. The possibility seems to be thoroughly answered. But I have found nothing regarding the the risk of of 'strangelets'. Has that also been answered? If so, where? -Harry Wertmuller
     
  13. ZapperZ

    ZapperZ 29,631
    Staff Emeritus
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    Gold Member

    Just to add to what derekmcd has linked to, the report relied heavily on the study done by Goodings and Mangano. This study appeared on ArXiv this morning.

    http://arxiv.org/abs/0806.3381

    Zz.
     
  14. For that matter, the report itself appeared on the arXiv this morning: http://arxiv.org/abs/0806.3414 (submitted last Friday). Goodings & Mangano only address black holes, though in much greater depth than the safety review itself.
     
  15. Re: LHC Hazards

    Are there any estimates on how likely it is that some sort of black holes would be produced?
     
  16. malawi_glenn

    malawi_glenn 4,727
    Science Advisor
    Homework Helper

    Re: LHC Hazards

    Have you read the articles?
     
  17. Re: LHC Hazards

    It is a very hard question. I would advise you to read Randall's papers, or lectures.
    Warped Extra-Dimensional Opportunities and Signatures
     
  18. Re: LHC Hazards

    I've read the LSAG report and I get that if the black holes are produced they are unlikely to be stable and even in the case they are they are probably harmless. I get that there is no reason for concern, that's not what I'm asking about. I'm interested in the likelihood of any kind of black hole being produced. I haven't read the Giddings/Mangano article, but it appears to be focusing on the effects of black holes should they be produced rather than the likelihood of them being produced. If there are such estimates within the article I would appreciate it if someone who has read it would point them out. Thanks.
     
  19. Re: LHC Hazards

    I would expect any such estimates to be very model-dependent. To my (very limited) knowledge, to get black holes at the LHC, the fundamental scale of gravity (Planck scale) must really be the TeV scale, not the very high energy scale it seems from naive dimensional analysis. You could get this from theories of large extra dimensions or warped extra dimensions, or apparently just by dictating it, and the production predictions depend on which model, with which parameters, you're considering. All of this is very speculative.

    A quick spires search gives a few results, including this large extra dimensions paper and this older discussion of various models. This recent paper uses non-observation of black holes in cosmic ray experiments to try to determine a "model independent limit for the four-dimensional reduced Planck mass", though they seem to work in a "model recently proposed to solve the hierarchy problem by lowering the Planck scale to the TeV region without the introduction of extra-dimensions". The article humanino posted should give some estimates in warped extra dimensions models.

    So you can check out those papers and references therein for predictions of black hole production in the framework of various BSM models.
     
  20. Re: LHC Hazards

    I doubt if there was a black hole, that it would absorb the world because of hawking's radiation. If it forms black holes, I highly doubt it will destroy the world, since fast collisions like that happens all the time, though detection could be difficult, so there is a possibility. World destruction, not a possibility.
     
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