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Concern Over Creating Black Holes

Posted by kdawson on Mon Sep 11, 2006 12:50 PM
from the nothing-to-fear dept.
Science
Maria Williams writes to tell us about worry surrounding the impending startup of CERN's Large Hadron Collider. Some fear that the device, in creating mini black holes, could jeopardize Life As We Know It. While the tiny black holes should evaporate quickly — throwing off so-called Hawking radiation that can be detected — CERN software developer Ran Livneh reminds us that "Any physicist will tell you that there is no way to prove that generated black holes will decay." The LHC site assures us there's nothing to worry about. The flap is reminiscent of the time the Relativistic Heavy Ion Collider went live. The worry then was that "negative strangelets" could gobble up the world.
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  • Please, for the love of God... (Score:5, Interesting)

    by daveschroeder (516195) * on Monday September 11 2006, @12:51PM (#16082503)
    ...no crap about John Titor [wikipedia.org] actually being a real person.

    Thanks.

    For those who don't know, in the John Titor story, the CERN LHC allegedly lays the groundwork for using artificial black holes as part of a time machine (made for the military by General Electric, of course!).

    (And no, John Titor is not a real time traveler.)

    For example:

    Along with the prediction of World War III, another notable prediction is that of a Civil war in America, which was predicted to begin in 2004, around the time of the presidential election, and would escalate until 2008, which, according to Titor, "[is] a general date by which time everyone will realize the world they thought they were living in was over."

    Even statements like this are subjective and many people still choose to believe; I'm sure there are many slashdot readers (judging from the kind of posts I see here) who believe we are currently in a nascent "civil war" and that, indeed, the "world they thought they were living in was over." This is all typical vague crap that can be viewed a variety of different ways, Nostradamus-style, and never soundly disproven, conspiracy-theory-style. Even now, people are arguing that John Titor's visit may have allowed us to "change our future". Yeah, because the mental giants who believe the John Titor story have had a huge impact on things.

    ...

    It's quite impressive how many people actually believe this tripe, though.

  • Ack! (Score:5, Funny)

    by ultramk (470198) <ultramk@noSpAm.pacbell.net> on Monday September 11 2006, @12:51PM (#16082507)
    Nothing for you to see here. Please move along.

    It's already begun!

    m-

  • Calling Dr. Freeman (Score:5, Funny)

    by CerebusUS (21051) on Monday September 11 2006, @12:52PM (#16082519)
    As long as Gordon Freeman is there to watch over the experiment, I think we'll all be okay. Maybe.

    I hear the Vortigaunts are our allies.

  • Creating them is a problem (Score:5, Funny)

    by Rik Sweeney (471717) on Monday September 11 2006, @12:52PM (#16082520) Homepage
    The worry then was that "negative strangelets" could gobble up the world.

    You see, the problem is that we could all get sucked off before we know what's going on.

  • The world didn't end last time... (Score:5, Funny)

    by Skyshadow (508) * on Monday September 11 2006, @12:52PM (#16082523) Homepage
    Seems to me that the only real problem with blowing this sort of thing off by saying "this is just like last time when we tried something that had a small chance of destroying the world and it worked out okay then" is that you really only have to be wrong once.

    "Oh shit! Yeah, our bad -- man, are our faces red. Sorry about that, everybody."
    • I think microscopic black holes couldn't eat up the earth due to the three stooges problem. They are so small that only an atom at a time can get in, but the gravity is strong enough to try to suck in more, so all the atoms get bunched up around the event horizon like the three stooges all trying to get through a door at the same time. Problem nullified. Whoop hoop oop! Nyuck nyuck, why I oughta!

      • Re:The world didn't end last time... (Score:5, Insightful)

        by dgatwood (11270) on Monday September 11 2006, @01:16PM (#16082787) Journal

        I don't think I buy that reasoning. That's like saying that a {particle beam, laser} won't work because the hole at the end of the tube is only big enough for one {atom, photon}.

        Except it's worse than that. As soon as things shift around a little so that a single atom goes in, the event horizon is now slightly larger. Repeat ad infinitum. All it takes is an occasional atom getting through.

        A microscopic black hole either dissipates or it doesn't. If it does, great. If it doesn't, we have a problem. It may take millennia to become a serious problem, but....

          • -if- it were the case that it does not dissipate, then there's a potential problem.

            You sound like Einstein - "um, i don't THINK the a-bomb will create a chain reaction of splitting atoms that will destroy the universe as we know it... but... just in case you might wanna get you some of that AFLAK insurance."

          • You are correct (Score:5, Interesting)

            by jd (1658) <[moc.oohay] [ta] [kapimi]> on Monday September 11 2006, @03:18PM (#16084007) Homepage Journal
            The size of the singularity is fixed, but the size of the black hole is not. The size of the black hole is directly proportional to the mass and should be a function of the entropy. Hawking radiation is the stream of particles of quantum foam which switch from being virtual to being real when the opposite particle is captured by the black hole. For reasons I do not entirely understand, it is assumed that the majority of particles captured will be the anti-particle, thus adding a negative amount of mass to the black hole. The companion particle will then be observed as radiation that appears to come from the vicinity of the black hole.

            There is an assumption in all of this, that the singularity is a point in space/time. This is how it is normally considered, but it is by no means the only interpretation that would be valid. Evaporation only applies within this assumption because entropy can only ever increase and the entropy of a physical point singularity that did not evaporate would be a constant. If a singularity does not exist as a point (there are other solutions, such as a "Kerr Ring Singularity") or doesn't actually exist as a physical entity at all (see below for a trivial theory where that would work), then all bets are off.

            This is a "just for amusement" theory, for the sole purpose of illustrating a singularity that would not violate the second law of thermodynamics and still not evaporate. Let us say that a singularity does have infinite gravity at the point at which it "exists", and that the curvature of space/time is a direct function of gravity, then what we call a singularity would not actually exist as an object. At all. What you would have is a "well" of essentially zero diameter where the sides were orthogonal to space and along the axis of time in a negative direction. The notion that "space and time end at a singularity" would not be true to an observer within the Universe, as they would not experience the well as anything other than a continuation of space. However, space would then not be simply-connected and it would be mathematically possible to show that there were mathematically definable points within an otherwise well-defined region that could not be reached.

            Now for the well itself. It cannot stop within the universe, because there are no forces along that axis. F=ma, so if F=0, then a=0. Nor can it continue forever, because it's going along the axis of time and time does not continue forever. There is exactly one place such a well could terminate, that being the moment of the Big Bang. (It stops there because there's nothing more to travel along.) It would be an express trip, there would be no possibility of getting off anywhere else. So it's just as well that, if this correct, anything that fell in would be crushed into quantum foam. Nothing else is going to fit in a well of zero diameter. Hawking's theory of imaginary time becoming real time would certainly fit this description.

            This theory would require that (a) black holes can only ever expand, (b) hawking radiation would contain equal numbers of particles and anti-particles (which would explain why we have such trouble finding any), (c) the recently-proved Poincare hypothesis does NOT apply to space/time, as it is no longer simply-connected, and therefore the Universe is NOT topologically equivalent to a hypersphere (which is going to upset the Chinese and Russians no end), and (d) the Hubble constant absolutely must be below 1.

            (That last one might not be obvious, so I'll explain. This theory recycles matter and energy through time to the big bang. Since you have a Universe's worth of matter/energy, you would not need inflation theory - which is "good" because inflation is an ugly hack whose chief benefit is that it works vastly better than every other mainstream theory in existance. But you can't guarantee that the whole Universe is recycled if the Universe is open. You can only guarantee 100% recycling if every possible photon and every possible particle is absolutely

            • Re:You are correct (Score:4, Funny)

              by KingSkippus (799657) * on Monday September 11 2006, @05:04PM (#16084913) Homepage Journal

              So... That's a yes, right?

            • Re:You are correct (Score:4, Insightful)

              by sjames (1099) on Monday September 11 2006, @05:27PM (#16085087) Homepage

              Actually, the idea behind Hawking radiation is that the intense gravity gradient of a black hole causes virtual particles to become actual near the event horizon. One goes in and the other escapes. It doesn't matter which one went in. Of course, a pair of particles just appearing out of the vacuum leaves a "hole" that must be filled (otherwise cionservation of mass/energy is violated). The energy to fill the hole tunnels out of the black hole itself. The net result is that it loses the mass of the escaped particle.

              It's worth noting that the size of black hole we're talking about here would evaporate in a small fraction of a second, most likely before it would even encounter another particle. It would have to somehow absorb a few hundred metric tons of matter to even last 1 second.

              Should all of this theory prove wrong, we may still feel safe since collisions with this level of energy DO occur in nature already and obviously haven't created "The Black Hole that Swallowed the Earth".

    • Re:The world didn't end last time... (Score:5, Funny)

      by 2short (466733) on Monday September 11 2006, @01:14PM (#16082760)
      I remember that last time, and I think a friend of mine summed it up best:

      "Scientists constructing a device that could potentially destroy the earth? Don't we have super-heroes to deal with this sort of thing?"

    • Re:The world didn't end last time... (Score:5, Insightful)

      by MORB (793798) on Monday September 11 2006, @02:20PM (#16083398)
      So what?

      If it doesn't destroy the world, scientific knowledge advances.
      If it does, no onw will be around anymore to worry about it.

  • its one way to go... (Score:4, Funny)

    by russ1337 (938915) on Monday September 11 2006, @12:53PM (#16082524)
    Well, it beats being hit by a bus....

    Standing at the pearly gates it would be a great converstation starter... "oh yeah? I was killed by a black hole...."

  • Am I the only one that read.... (Score:5, Funny)

    by LordPhantom (763327) on Monday September 11 2006, @12:53PM (#16082527)
    ....Hard On Collider? I think I'd prefer an earth swallowing black hole.
  • The black holes would only eat up Kurt Vonnegut. However, the efect would be the same as if they ate up the whole world, since it's all a figment of his imagination.

  • Okay... (Score:5, Insightful)

    by addaon (41825) <addaon+slashdot@gmail.com> on Monday September 11 2006, @12:53PM (#16082531)
    Being cautious about a potentially real issue is one thing, but of course the big issue here is that collisions of similar energy happen, if not commonly, at least not entirely rarely due to cosmic rays. If the world could be destroyed by the side-effects of such a collision, we wouldn't be here to be nervous about it.
    • Precisely, although, if I may add a bit as to why people might still be afraid of this research ...

      It's natural to fear what you don't understand. It might even be a quality of a species that determines its success as many things in nature are quite dangerous. For better or for worse, mankind has this built in as a default setting no matter who you are whether you're fearing a black hole or suffering from xenophobia.

      I am not a physicist but I think the fears here are quite unfounded. All the math and theory point to a black hole having a finite event horizon. If the black holes they are producing are microscopic and last relatively little amount of time, they shouldn't be very dangerous. I think this has been covered before [slashdot.org].

      It is interesting though, because I believe a black hole's event horizon has a radius proportionate to the amount of mass it consumes. I believe that if you make them small enough, however, they don't last long enough to expand. I would be concerned if they were attempting to make massive singularities to destroy garbage heaps with these but I don't see how those would be possible to create as the only known method is to accumulate so much mass in such a small volume that gravity crushes it into a singularity. My understanding of the collider is that it smashes particles together at a fast rate and, as a result, very tiny and brief black holes may result. As this article [nature.com] states:
      The physicist Stephen Hawking predicted in the 1970s that black holes would evaporate by radiating away their energy. For astrophysical black holes this is a very slow process, but extremely small black holes should last about as long as a snowflake in hell.

      People will, as always, fear what they don't understand so I believe it's hopeless to quell all fears about physics research. I'm sure a lot of people are concerned about this being the next "atomic bomb" technology. Where we "drop" black holes on enemies. Though that doesn't really make sense, it still could have military applications such as creating electromagnetic devices that are so strong they displace gravity and aiming them at your enemies. Sure would make for a cheesy sci-fi book whether it was true or not!

  • No way? (Score:5, Funny)

    by Anonymous Coward on Monday September 11 2006, @12:54PM (#16082556)
    "Any physicist will tell you that there is no way to prove that generated black holes will decay."

    Of course there's a way. Empirical research, just like they're doing. First you make a black hole, then you see if it expands until it destroys all life on earth. Simple, straight forwards, effective.

  • SETI paradox resolved (Score:5, Interesting)

    by Gary W. Longsine (124661) on Monday September 11 2006, @12:55PM (#16082557) Homepage Journal
    Where are they? Gone.

    Civilizations routinely destroy their home planet by creating miniature black holes thereupon whilst trying to figure out what makes them tick. Technology advances faster than democracy, and it has never yet in the long history of the universe been put to a vote.

  • Perspective (Score:5, Informative)

    by truthsearch (249536) on Monday September 11 2006, @12:55PM (#16082561) Homepage Journal
    Some scientists were very concerned the first atomic bomb would produce so much heat it would ignite the atmosphere and burn the entire surface of the earth. Fortunately it didn't happen. But it's good that people bring up these ideas so we challenge assumptions and try to be safe while still advancing science.

  • I thought everyone knew... (Score:5, Funny)

    by LinuxGeek (6139) * <linuxgeek&djand,com> on Monday September 11 2006, @12:56PM (#16082566)
    This is the reason that the Earth entry was changed from "Harmless" to "Mostly harmless".
  • Edward Teller speculated that an atomic weapon could ignite the atmosphere. Another physicist discredited and disproved the idea, but the fear wasn't laid to rest until the actual weapons were used.

    http://en.wikipedia.org/wiki/Manhattan_Project [wikipedia.org] (wikipedia, blah blah blah)

    • Re: (Score:3, Informative)

      by zippthorne (748122)
      No, the fear wasn't laid to rest until Teller and other scientists did the math. They didn't do the experiments until after they made the calculations.

    • Re:There was concern over atomic weapons too... (Score:4, Interesting)

      by dpbsmith (263124) on Monday September 11 2006, @01:57PM (#16083201) Homepage
      That fear resurfaced during the 1954 "Bravo" shot. It was twice as powerful as expected, and as physicists watched and saw the cloud keep expanding and expanding and expanding, with no signs of stopping, at least some of them momentarily wondered whether the atmosphere had been ignited after all.

      But don't worry. Physicists will never make a mistake again. And, hey, the atmosphere didn't ignite, so, no problem.

  • The biggest word in that sentence (Score:3, Insightful)

    by Weaselmancer (533834) on Monday September 11 2006, @12:58PM (#16082602)

    While the tiny black holes should evaporate quickly...

    The biggest word in that sentence is should.

  • Cosmic rays have prior art (Score:5, Informative)

    by arevos (659374) on Monday September 11 2006, @01:02PM (#16082641) Homepage
    Primary cosmic rays impact the earth all the time, and these often have far higher energies than even our largest particle accelerators are capable of producing. For any experiment we attempt, we can be reasonably sure that colliding cosmic rays have already produced the same results, sometime within the past few billions years. If we could create massively destructive black holes through our particle accelerators, one would expect that stray cosmic rays would have already done so.

      • Re:Cosmic rays have prior art (Score:4, Interesting)

        by arevos (659374) on Monday September 11 2006, @05:05PM (#16084924) Homepage
        There's never any proof per se in science. There have been, however, many experiments, observations and measurements of cosmic rays since they were discovered in 1912. In 1954, MITT used 11 scintillation detectors to measure the energy spectrum of cosmic rays, and found it to extend beyond 1e20 eV. To put that into perspective, our largest particle accelerator, the Tetravon Accelerator at CERN, can only manage 1e12 eV. We'd need over 100 million times the power to start getting beyond the capability of cosmic rays, which is a pretty comfortable margin in my book :)

  • Fermi knew the answer long ago (Score:5, Informative)

    by Framboise (521772) on Monday September 11 2006, @01:04PM (#16082665)
    This type of fear occurred many times during the nuclear physics history, when higher and higher energies were explored. The answer against fears of unknown catastrophic effect has been that some cosmic rays are much more energetic than any artificially accelerated particles (10^21 eV for some cosmic rays in comparison to the feeble 10^12 eV in today accelerators such as LHC). For sure the Earth and the Sun did already receive zillons of cosmic rays without disappearing...

  • Natural Particle Accelerators (Score:5, Interesting)

    by noretsa (995866) on Monday September 11 2006, @01:04PM (#16082668)
    If it were really so easy to destroy the world it would have happened long ago.

    For example, there are as yet little-understood phenomena that can accelerate particles six orders of magnitude faster than anything achievable in a lab. Try reading about Ultra-high-energy cosmic rays [wikipedia.org].

    More specifically read the story of the Oh-My-God Particle [fourmilab.ch]. This was a proton detected in October of 1991 that had an energy of 3.2 * 10^20 eV. The equivalent energy of a baseball thrown at 55 mph... all in a single proton travelling at 99.99999999999999999999951% the speed of light!

    While something travelling that fast has little probability of interacting with anything you could imagine the surprise if one of those hit you! I think that the fact we are alive with such powerful forces already at work in our universe means we have little to fear.

  • Utter Crap (Score:5, Interesting)

    by bockelboy (824282) on Monday September 11 2006, @01:07PM (#16082688)
    I work one of the LHC expirements (low-level grad student, no one important), and this is utter crap.

    Yes, there are physicists who are concerned. There is a chance that this could happen - one of those "if everything we know about high energy physics is completely wrong, this could happen". There is an approximately equal chance that Pat Buchanan will be nominated as the Democrat candidate for president in 2008. No physicist can prove that this won't happen - just like no physicist can actually prove that Superman doesn't exist.

    Unfortunately, it's about the only way a reporter can "sexy up" a story about a particle accelerator. I can't wait to see the headlines in 2007 - "Will the Earth end tomorrow?" (subheading: "Respectable scientists say 'No'").

  • OK, imagine the black hole not decaying... (Score:5, Funny)

    by Yonzie (516292) on Monday September 11 2006, @01:10PM (#16082724) Homepage
    What will happen?

    We'll all die. Simultaneously. Noone will feel anything.

    What's the big problem aside from the end of the earth?

  • Has anyone seen my car keys? (Score:3, Funny)

    by Easy2RememberNick (179395) on Monday September 11 2006, @01:11PM (#16082732)
    "Has anyone seen my car keys? I set them right next to the collider."

      This reminds when I read Brian Greene's Elegant Universe, he mentioned that there was a possibilty of creating another Universe when (if it were possible) smashing together Superstrings. Something like that, I'm not sure where I put the book.

  • Better we kill ourselves... (Score:3, Funny)

    by thebdj (768618) on Monday September 11 2006, @01:15PM (#16082769) Journal
    before the big asteroid or comet comes. Or the sun goes red giant. Or the sun shoots off enough matter to defeat the ozone and expose us all to radiation. (Yes, I have heard this one.) Oh, or Yellowstone goes all explosion on us and brings about a second ice age or something. (There was a Docu-drama on this one.) Oh, or maybe the moon can be partially destroyed and threaten to crash into earth. (Reference to a ABC Family comedy or in some ways to Cowboy Bebop). Oh, or nuclear winter. I am sure I forgot some.

    But better us then nature!

  • And here I sit... (Score:5, Funny)

    by TimeOnMyHands (995573) on Monday September 11 2006, @01:25PM (#16082894)
    working in a small cubicle, doing nothing that will ever even change the world, while these guys are working on a project that could destroy the world! I'm so jealous... I've made bad choices.

  • I bet you $1,000,000... (Score:4, Funny)

    by exp(pi*sqrt(163)) (613870) on Monday September 11 2006, @01:28PM (#16082931) Journal
    ...that the world won't end as a result of this experiment. Any takers?

  • Nature itself tells us: no doomsday (Score:5, Interesting)

    by xPsi (851544) on Monday September 11 2006, @03:12PM (#16083954)
    IAAP (who worked on RHIC physics). The same arguments used in 1999-2000 with RHIC (and with Fermilab before that) should be used here. There is no chance for doomsday catastrophe. While these events at the LHC are "high energy" from a human technology point of view (per event per particle), the LHC generates low energy events at low rates compared to nature itself. There are millions of LHC-like events (or "greater") per second that occur on the surface of the moon alone, not to mention in our own atmosphere from cosmic rays. While cosmic rays are carefully studied, the reason we build machines such as RHIC, Fermilab, and LHC is, as scientists, we like to study events systematically and carefully at specific energies in a relatively low-noise environment (difficult to do with cosmic rays, which is why we might not formally detect strangelets or black holes in such events when measured). However, if there were problems with voracious black holes, stranglets, or other doomsday scenarios due to elementary particle collisions, they would have happened long, long ago in nature (locally) -- we would have seen evidence for it on the moon, atmosphere, etc. (assuming we survived long enough to witness it with such a high event rate - it probably would have happened long before we had a chance to even evolve).


    See Doomsday Fears at RHIC [highbeam.com] in particular the reference Review of Speculative "Disaster Scenarios" at RHIC [arxiv.org]

  • Where do they think black holes come from!?!? (Score:5, Funny)

    by brundlefly (189430) on Monday September 11 2006, @03:50PM (#16084325)
    Every black hole in existence in the universe is a result of some fairly advanced civilization reaching a point where each eventually says "Hey, let's build a Large Hadron Collider and see what happens".

    The rest, as they say, is astronomical history....

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