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Concern Over Creating Black Holes

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.

14 of 597 comments (clear)

  1. Please, for the love of God... by daveschroeder · · Score: 4, Interesting
    ...no crap about John Titor 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.

  2. SETI paradox resolved by Gary+W.+Longsine · · Score: 5, Interesting

    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.

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    If you mod me down, I shall become more powerful than you could possibly imagine.
    1. Re:SETI paradox resolved by crabpeople · · Score: 1, Interesting

      There was a book where they kept building bigger and bigger experiments, the latest one with a diamater of part of the solar system - and one of the characters postulates that that was how the big bang always started. Scientists of an advanced civilization solving the only problems left to solve would eventually try to re create the big bang out of a search for knowledge.

      Forget the name of the book though.

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      I'll just use my special getting high powers one more time...
  3. You Fear What You Don't Understand by eldavojohn · · Score: 4, Interesting
    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.

    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 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!
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    My work here is dung.
  4. Natural Particle Accelerators by noretsa · · Score: 5, Interesting
    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.

    More specifically read the story of the Oh-My-God Particle. 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.

  5. Utter Crap by bockelboy · · Score: 5, Interesting

    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'").

  6. Black Holes and Birth of our World by Intangible+Fact · · Score: 2, Interesting

    Knowing the government and their previous actions on subjects like this I think they have already experimented with the mini black holes. Most scientific information that would give the general public a stir is withheld for many years until the people are ready. I believe that black holes are not time traveling devices, but more of a door to a new universe. Black holes suck in anything and everything, including light. Our universe started from a Singularity in which matter was infinitely compressed and space and time was infinitely distorted. Black holes compress and distort matter and time. Put two and two together and what do you have? The birth of our universe. I believe our universe was born inside of a black hole and that we are currently living and evolving inside of it. Thus means every black hole we see out in space possibly is a gateway to another universe. Tell me what you think?

    1. Re:Black Holes and Birth of our World by libra-dragon · · Score: 3, Interesting

      I think each block hole is created by civilizations conducting experiments similar to ours. They're thinking that this is just too small and unstable to turn into one of those real big black holes out there...

  7. Re:There was concern over atomic weapons too... by dpbsmith · · Score: 3, Interesting

    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.

  8. Nature itself tells us: no doomsday by xPsi · · Score: 5, Interesting
    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 in particular the reference Review of Speculative "Disaster Scenarios" at RHIC

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    i\hbar\dot{\psi}=\hat{H}\psi
  9. You are correct by jd · · Score: 5, Interesting
    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

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    It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
  10. Re:The world didn't end last time... by Thuktun · · Score: 2, Interesting

    A black hole eating up the Earth appears in the Hyperion series, usually referred to as the "Big Mistake of '08".

    Curiously, the LHC is going to come online in 2007. Hope that's just coincidence.

  11. Re:Cosmic rays have prior art by arevos · · Score: 3, Interesting

    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 :)

  12. Is Hawking worried? by Kumiorava · · Score: 2, Interesting

    If not then I might go on with my life and not to bother with this.

    If he is worried then I guess I should stop saving for my retirement fund.