Saturday, September 06, 2008

End of the world, or not, post

I'm getting mightily annoyed with the way the media, and particularly science journalists, are reporting the "end of the world" stories regarding the LHC. Not because they are being sensationalist (though a small fraction are), but because they are, more often than not, being overly dismissive while at the same time clearly ignorant of the detail of the debate.

For example, the science editor at The Times is Mark Henderson, who himself has no science background, and certainly looks very young. He wrote in The Times that:

Once again the cry has gone up that the accelerator could create a black hole that would devour the planet. Legal challenges have sought to halt it, and these have been more widely reported this week than the project itself.

Yet the claim is utterly ridiculous. ...

This isn't a story that's worthy of serious discussion, even as kooky fun. It might sound harmless, but it feeds stereotypes of crazy and reckless boffins who know everything about nothing and nothing about everything, and encourages the contemptible but widespread view that scientists are not to be trusted.
"Utterly ridiculous" ideas generally don't get responded to by detailed safety studies, Mark.

Henderson and his ilk seem to have missed this comment by Mangano, the physicist most credited with this year's safety review, reported earlier this year:
"If it were just crackpots, we could wave them away," the physicist said in an interview at the European Organization for Nuclear Research, known by its French acronym, CERN. "But some are real physicists."
Mark and most other science journalists writing reassuring articles this week also seem to have missed the issue raised only in August by astrophysicist Rainer Plaga that there might be another mechanism (other than the earth being eaten by a black hole) by which micro black holes might be dangerous. Yes, Mangano and Giddings have responded to this claim, but isn't this a newsworthy addition to the current reporting?

Plaga's concerns are particularly newsworthy because, as I noted a few posts back, he seems well and truly within the mainstream of astrophysicists. He writes:
The luminosity of a mBH accreting at the Eddington limit with the parameters assumed above corresponds to 12 Mt TNT equivalent/sec[11], or the energy released in a major thermonuclear explosion per second. If such a mBH would accrete near the surface of Earth the damage they create would be much larger than deep in its interior. With the very small accretion timescale (≪ 1 second) that was found with the parameters in section 3, a mBH created with very small (thermal or subthermal) velocities in a collider would appear like a major nuclear explosion in the immediate vicinity of the collider.
I have asked nice physicist Sabine Hossenfelder, who has discussed the LHC safety issues before at length at her Backreaction blog, about this. Unfortunately, she has not seen Plaga's paper or Mangano's reaction, and is showing little interest in reading them any time soon. (I think she doesn't really believe any micro black holes are likely to be created, and that may well explain her lack of concern.)

Therefore I don't know who else to ask in the physics world as to whether the Mangano response is conclusive.

Well, in the interests of citizen science journalist, I have sent a short email to Plaga himself, asking if the Mangano/Giddings comments on his paper has caused him to change his mind.

I will let you know if I get a response.

UPDATE: No response yet, but I just wanted to clarify that, as explained here, on 10 September the LHC is only planning on getting the first beam circulating in one direction. There won't be any no particle collisions until they get another beam, going in the opposite direction, up and running. According to the Guardian:

"If the beam goes all the way round on the first go, that would be quite amazing. It's never happened in the history of particle colliders," said Cern's James Gillies. If the test is successful, scientists may try to send the beam around in the opposite direction, though first collisions are not expected until next month.

They expect to spend a few months getting to grips with the machine before putting it to work in earnest.
So, even in the worst case scenario, we all have at least another few weekends ahead of us. Drink up, be merry, ask questions, etc.

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