Friday, April 04, 2008

Some decent stuff about mini black holes

Before I go away for the weekend, I thought I would point out these developments.

At last, at least one physicists' blog goes into a lot of detail about what they think would happen if mini black holes from the LHC did not evaporate via Hawking Radiation. This is well worth reading, although my feeling is still that it a pretty complex question and may yet be the subject of some uncertainty.

It seems to me, for example, that Bee's explanation of a mini black hole passing through the earth and hitting a subatomic particle does not coincide exactly with Greg Landsberg's explanation in 2006:
They would each take about 100 hours to gobble up one proton. At that rate, even if one did not take into account the fact that each black hole would slow down every time it gobbled up a proton, and thus suck down matter at an even slower rate, "about 100 protons would be destroyed every year by such a black hole, so it would take much more than the age of universe to destroy even one milligram of Earth material....
Compare that to Backreaction:
Nobody knows exactly what will happen when a tiny black hole hits a nucleon. On the scale of the black hole, the nucleon is about 1000 times larger in diameter, and a very dilute cloud of a few quarks and gluons. It may be that the black hole hits one of these partons, as they are called, thus disrupting the nucleon and carrying away a fraction of its mass. There is no theory to describe this, and there are all kinds of problems involved, as to what happens to confinement, colour neutrality, and so on. But whatever happened, in the end, the black hole may have gained, in the most extreme case, the mass of a nucleon.
It may be that they are in complete agreement, if Landsberg's explanation was given in more detail. But it reads to me like there is some uncertainty.

That said, they both agree that very, very few mini black holes should have less than escape velocity. That's good, although again it appears to me that Backreaction's estimate and Landsberg are different.

Another physicist spends a lot of time pointing out that the very limited experience in physics of litigant Walter Wagner, and getting upset that the media does not report this clearly. But on the more important point of why Wagner is wrong (in detail), we haven't heard from Steinberg yet. (Maybe he will just agree with Backreaction's analysis.)

Really, if physicists are unhappy about Wagner getting publicity over this, why didn't they simply address the issue in detail when asked about it over the last couple of years by the likes of James Blodgett. Instead, the reaction was (by and large) very dismissive, especially once you asked "what if HR does not exist?" I know that Greg Landsberg did go into a fair amount of detail in answers to James Blodgett, but he was pretty much the exception, as far as I know. (And he eventually stopped taking questions anyway.)

Only now, it seems, are we getting the detail which indicates that it was never a completely stupid question.

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