Issue / Micro Black Holes

Q: Is it time for the precautionary principle??

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From "Warped Passages" by Lisa Randall (Harvard Physics Dept.), page 380 --

[...] "If this is the case, black holes might be produced at close to a TeV energy, and such higher-dimensional black holes would be a gateway to a better understanding of classical gravity, quantum gravity, and the shape of the universe. If the relevant energies [...] are sufficiently low, black hole production could be imminent; they could be formed at the LHC."

[NOTE: the Large Hadron Collider will go online at CERN in Switzerland in this decade.]

"The higher dimensional black holes that would form at colliders would be far smaller than the ones in the universe around us. They would be comparable in size to the very tiny extra dimensions. In case you are worried, rest assured that these small, very short-lived black holes won't pose a danger to us or our planet; they'll be gone well before they could do any damage. Black holes don't last forever: they evaporate by emitting radiation through the phenomenon known as Hawking radiation. But just as a small drop of coffee evaporates more quickly than a full cup, so the small black holes that could conceivably be produced at colliders will evaporate almost immediately. Nevertheless, if they are produced, these higher-dimensional black holes would last long enough to leave visible signs of their existence at a detector. They would have a very distinctive appearance since they would produce many more particles than you would find in ordinary particle decays, and these particles would go off in all directions."

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Of course this raises the question -- ARE YOU SURE? Gravity at high energies and small distances is still squarely in the realm of theory. What if due to some as yet undiscovered physical principles, the evaporation rate is not as fast as predicted? Or suppose a micro black hole were to immediately encounter and absorb a hefty amount of mass, through a fortuitous series of very rapid collisions, thus bulking up and extending its life long enough to encounter yet more matter, triggering a chain reaction gravitational collapse?

According to Exit Mundi NL (see under Human->Black Hole), a likely scenario is that the micro black hole(s) would be quite tiny at first and, seeing that matter is mostly empty space, would head for the center of the Earth, hitting electrons or nuclei occasionally on the way down. Then as they gained mass, the entire Earth would be sucked in, yielding a black hole 9 mm in diameter with the same mass as the present Earth, which the Moon would continue to orbit around as before.

Acceleration due to gravity is 32 feet per second per second, and our planet's total mass does not change, so the rate of collapse is the time it would take for all our matter to fall 4,000 miles. Bottom line, in a couple of minutes everyone and everything would disappear.

Should we be demonstrating in Geneva? Lying down in front of the trucks delivering the giant electromagnets? Walking around in robes urging everyone to Repent Now, because the End is Nigh?

It would be helpful to see a set of well-reasoned analyses showing why this is NOT a problem, but so far my inquiries to theoretical physicists have gone unanswered. Perhaps the lure of all those Nobel Prizes waiting to be won is clouding their vision, but as we know they are not awarded posthumously!

Originally posted 1/18/06