The Geneva area a few minutes after LHC startup April 14, 2008Posted by dorigo in astronomy, humor, news, personal, physics, science.
I received this morning the poster of a workshop on Dark Matter searches at the LHC, which will be held in my University on April 22nd. This is a single afternoon of talks addressed to students of Physics, to educate them on the connection between particle physics and cosmology in view of the start of the collider this fall. Upon glancing at it, I immediately sensed the subliminal message it sends to whomever has been reached by the headlines on the recent lawsuit concerning the risk of black hole creation in the high-energy proton-proton collisions… Here is the poster:
The galaxy has of course nothing to do with an expanding black hole, but it still sends a sinister message. Let me say it here again: black holes will NOT be created at LHC. Scientists cannot even assess the chance of that happening, because the probability that 1) Large extra-dimensions exist in nature, 2) the scale of quantum gravity being both fine-tuned to allow black holes to be produced by LHC and not by past colliders, and orders of magnitude smaller than what it is most reasonable to conceive, is too small to be investigated meaningfully.
In any case, even if microscopic black holes were created at LHC, they would evaporate instantly, due to a phenomenon, Hawking radiation, which only rests on general relativity and quantum gravity, and is thus on much more solid ground than the very production of black holes. And in any case, even if black holes were created and they did not evaporate, they would escape the Earth without more than a few nuclear interactions. And in any case, even if scientists were wrong on all the previous counts, collisions like the ones LHC will produce are generated everywhere by cosmic rays, so the black holes generated inside the LHC would be nothing new under the sun.
For a more meaningful discussion of these issues, please visit this instructive post at backreaction.