the micro black hole dilemma, revisited

November 16, 2009

Do you hear the rumble in the background? That’s the Large Hadron Collider getting ready to smash particles and either seal the standard model of particle physics for the foreseeable future, or overturn much of what we know about quantum mechanics. And of course, once again people are asking whether black holes will form as a result of smashing atoms at nearly the speed of light and if the world is about to be destroyed. Once the first collisions are imminent, don’t be surprised to hear doomsday chatter about micro black holes growing so large, they escape and devour the Earth as they either sink stealthily into the ground, or spectacularly blast the collider to pieces and unleash the kind of explosive doom on the word, it would move Michael Bay to tears.

smashed collider

Believe it or not, many physicists racked their brains about the possibility of micro black holes being made at the LHC and so far, all of them are sure that unless we’re completely way off base about the quantum world, a micro black hole couldn’t possibly harm us. The problem is mass. The smaller the black hole, the less pull it has, the more unstable it is and the faster it evaporates into nothing. Because its mass would be comparable to a few protons, it would evaporate so quickly, it wouldn’t have enough time to actually exist according to very basic calculations. On top of that, it’s radius would be smaller than Planck Length so it would also be way too small to register as a physical object. But again, those are just quick and dirty estimates. The reality of a micro black hole is much more complex and according to a recent paper, there is a chance it could be born and live long enough to be detected. Of course there’s a hitch. It would need five space-time dimensions to do it.

According to a five-dimensional construct of space and time known as the Randall-Sundrum model, there’s a dimension which experiences a gravity leak. Micro black holes would be anchored in this dimension and try to accrete matter faster than their predicted evaporation. Thus, they could last far longer than your quick and dirty estimate would allow them, but they would still evaporate within fractions of a second. To actually grow into an immense monster with which we’re familiar, would take longer than the lifetime of the entire universe. And it’s not guaranteed by any stretch of the imagination because this black hole would need optimal conditions and to be fed with enough matter in enough time and with the kind of precision that would put any atomic clock to shame. The worst possible case scenario in realistic terms? We’d get a micro black hole with the mass of a bacterium which would take countless eons to grow to a truly noticeable size. Considering that the sun would burn out well before that, a micro black that survived by being anchored to an extra dimension is the absolute least of our worries as far as the cosmos is concerned. And on top of that, we need to keep in mind that so far, the only place where the Randall-Sundrum model exists is in the realm of mathematics.

See: Casadio, R., et. al (2009). Theoretical survey of tidal-charged black holes at the LHC, arXiv: 0911.1884v1

[ illustration from the video game Dead Space, story tip by Dr. Ian O’Neill ]

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  • Loeck

    I heard something about a thing called strange matter that might come about by the operation of the LHC, and apparently is very dangerous, it turns everything else it touch’s into strange matter.

  • A black hole does not accrete until matter enters its event horizon. Million solar mass black holes’ accretion is glacial because angular momentum is conserved. Stuff does not “fall in,” it swirls around the drain and shoots out orthogonal to both sides of the accretion plane along the black hole’s rotation axis.

    Any created nano-black hole will have gonzo “rapidity.” It will be traveling at a goodly fraction of lightspeed in the lab frame. Car crashes are messy with flung parts. A drain hole smaller than the diameter of an atomic nucleus will be through the Earth and gone before it swallows anything. The mean diameter of the Earth is 0.0425 light-seconds and its escape velocity a mere11.186 km/s.

    God save us from the congenitally inconsequential.

  • Doug Dastardly

    After seeing the (Fantasy Sci-Fi) movie 2012, I think that a mini-black hole would be an exciting way to end it all, so long as I don’t die in the first couple of minutes. I would like about 30 minutes watching the world crumble around me…talk about an adrenalin rush. (LOL)
    But then again, I am a senior citizen that has just about done it all and is certainly not afraid of biting the bullet. Of course this gloom and doom must really suck for the younger population.
    I will not be loosing any sleep at all when they fire up the LHC since the only thing that will be generated, will be knowledge. The end is not NEIGH; and the future is so bright that I have to wear shades.

  • jimbo

    Just pointing something out here…

    In one breath you say “..or overturn much of what we know about quantum mechanics…”. Then you state that mini black holes could not be created “…unless we’re completely way off base about the quantum world…”. So is it not possible if the LHC overturns much about what we know about quantum mechanics, this could mean we were “way off base” in our understanding of QM?

  • Daniel

    Could be the solution to this paradox… :D

  • There are many out there who totally misunderstand science and physics, but seem to have won a publishing contract so they can promote their misunderstanding as truth.
    At this point, the general public will have a much harder time thinking critically about the dangers of science.

    For instance, this particular weirdo is publishing a sci-fi books on wormholes, totally raping the physics and physics history involved, and promoting the book via his blog. And his readers are lapping it up! Of course he is trying to promote Christianity from a physics standpoint… so you can see the futility in getting the guy to see reason.

    But it is easy to see what scientists are up against. They spend their time doing science, while a larger number of people with much more time on their hands mis-represent science. Sometimes I pessimistically feel that scientists are facing a losing battle.

  • No serious person thinks that the LHC might create a black hole and suck us all up. But at least several non-crackpot physicists and philosophers have considered that a stable strangelet is a possibility.

    What is completely unscientific are when physicists give probabilities like “one in a trillion” of a stable strangelet destroying the Earth. They are failing to take into account the prior probability that they are wrong due to unknown unknowns, which is a heck of a lot larger than one in a trillion.

  • Greg Fish

    “What is completely unscientific are when physicists give probabilities like ‘one in a trillion’ of a stable strangelet destroying the Earth.”

    Actually, that one in a trillion chance is the assumption that they’re wrong about some of the key factors of the Standard Model which is so exhaustive, it covers all we know about the behavior and interaction of particles.

    The problem with the strangelet hypothesis is that it assumed that strange matter would create more strange matter and it would have a negative charge in massive collisions. But the LHC is not even powerful enough to recreate the energy of cosmic ray collisions, much less create the negatively charged strange matter which is not repelled by what we know as normal matter.

    On top of that, we don’t know if negative strange matter would actually convert normal matter so the ice-nine scenario is making two assumptions, one of which needs a much more powerful collider then we have on this planet.