Cosmic rays, heavy ions, and the safety of the LHC

[LSR]

Cosmic rays, heavy ions, and the safety of the LHC

One of the main safety arguments for the LHC is that Nature has already conducted the LHC experiment many times over. The current official safety report states that:

…Nature has already completed about 10^31 LHC experimental programmes since the beginning of the Universe. Moreover, each second, the Universe continues to repeat about 3 x 10^13 complete LHC experiments. There is no indication that any of these previous 'LHC experiments' has ever had any large-scale consequences.

This calculation is relevant only for the LHC's programme of proton-proton collisions, with a design energy of 14 TeV. The safety report includes no comparable calculation for the LHC's programme of lead-lead collisions, with a design energy of 1148 TeV. The report estimates that once it reaches peak luminosity, one month of the LHC's heavy ion programme each year for ten years will result in up to 8 x 10^10 lead ion collisions. The report presents no compelling evidence that even one lead-lead collision at a centre-of-mass energy of 1148 TeV has ever taken place before, let alone that 2.4 x 10^24 such collisions occur each and every second.

See the original text at:
http://www.lhcsafetyreview.org/docs/cos ... y-ions.pdf

[chelle]

Good point, but at the end of the day they'll say that there are:

... ultra-high-energy cosmic ray (UHECR) is a cosmic ray particle with a kinetic energy greater than 10^18 eV, far beyond both its rest mass and energies typical of other cosmic ray particles.
http://en.wikipedia.org/wiki/Ultra-high ... cosmic_ray