You are definitely right in saying cosmic rays have been measured for years, but the majority of them consist of protons, and heavy ions are more rare. Cosmic rays consisted of protons are known to reach high energies (10^20 eV), but are there any direct measurements concerning leads ions?
"…because of the low flux of ultrahigh-energy cosmic rays, the mass composition cannot be measured directly. Instead, it is inferred from measurements of the extensive air showers—the cascades of high-energy ions created when incident cosmic rays collide with atoms in the atmosphere."
"All of the natural elements in the periodic table are present in cosmic rays, in roughly the same proportion as they occur in the solar system."
"The safety margins we have derived [for RHIC] would improve by the same factor [for LHC]."
What else do you want? If you want more, try sending your questions to CERN, because you're asking for information that I don't have.
Also, I ask you again, do you have some information concerning these collisions that thousands of scientists don't have? This hysteria has gone on with the public for more or less every single particle accelerator ever built. RHIC was painted as a doomsday machine ten years ago, and LHC has essentially been an encore of that circus (initially spearheaded by the same guys who attacked RHIC).
For a long time these ultra high cosmic rays were thought to be made of iron, but a recent study found them to be protons after all. http://www.insidescience.org/research/scientists_prove_cosmic_rays_are_made_of_protons
Maybe you missed something from that brief article:
"Cosmic rays have energies that can be much higher than anything produced by physicists. HiRes looks at the composition of cosmic rays with energies a million times greater than those generated on Earth, such as in the accelerator at the Large Hadron Collider."
Also, that is brand new information (published less than a month ago), and it by no means suggests that iron-iron or even lead-lead collisions do not or cannot occur in the atmosphere. Even beyond that, lead has been used in collisions for years, so we again go back to: do you have some information concerning lead ions that thousands of scientists don't have?
This bring me back to the RHIC safety report, where the authors claim they can't possibly know which type of collision (proton, iron, lead etc.) is more effective at triggering a vacuum instability event, so they have to make sure there are higher cosmic ray collisions from both types.
Now you might say this document is 11 years old, but since the LSAG said no new information was brought into consideration regarding this particular doomsday scenario, it seems fair for us to make conclusions based on that paper.
The idea of a vacuum instability event is frightening (a lot more than people quoting the bible and Nostradamus), and I want to be absolutely sure we have nothing to worry about.
Just knowing lead ion collisions in cosmic rays suppress 2.76 TeV would make me more calm.
"…because of the low flux of ultrahigh-energy cosmic rays, the mass composition cannot be measured directly. Instead, it is inferred from measurements of the extensive air showers—the cascades of high-energy ions created when incident cosmic rays collide with atoms in the atmosphere."
"All of the natural elements in the periodic table are present in cosmic rays, in roughly the same proportion as they occur in the solar system."
"The safety margins we have derived [for RHIC] would improve by the same factor [for LHC]."
The LSAG safety report, if you've read all of it, also states: "However, if LHC collisions could produce vacuum bubbles, so also could cosmic-ray collisions. This possibility was first studied in [7], and the conclusions drawn there were reiterated in [8]. These bubbles of new vacuum would have expanded to consume large parts of the visible Universe several billion years ago already. The continued existence of the Universe means that such vacuum bubbles are not produced in cosmic-ray collisions, and hence the LHC will also not produce any vacuum bubbles."
I think you're getting confused over what a particular ion is (i.e. lead, gold or iron) versus the centers-of-mass and velocities of particles in a given collision.
Seriously, try asking CERN. Further, try watching this lecture. You can also usually find the e-mail addresses of scientists who author various papers, sometimes on their university web pages. Some scientists welcome random public inquiry about the work, others not so much. Be forewarned. You might additionally have a look at this forum and website. Sadly, even that board has a certain base of users who ask questions, get answers, then claim nobody answered their questions. So I'm becoming increasingly convinced that some people just can't be pacified. Maybe they don't even want to be, because nothing seems good enough for them.
The only alternative to trusting the conclusions of scientists in a particular field, is to become a scientist in a particular field. If you're still worried after that, publish a paper explaining why.
I don't know what else to tell you other than repeat that the information you asked for has been provided. If that isn't sufficient, I apologize, but I can do no more, other than provide the additional sources linked above.
Natalie (guest) 19 Jul 2010 18:59
