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This is an old revision of this page, as edited by Kleuske (talk | contribs) at 11:47, 28 February 2016 (→Doesn't a photon travel X light-years in X years?). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Iron Nucleus

I've changed in the beginning most likely a proton into Iron Nucleus, and halfway in the article subatomic particle into Atomic Nucleus; because of this article: the team has found evidence that these highest-energy cosmic rays might be iron nuclei, rather than the protons that make up most cosmic rays. http://www.nature.com/news/2010/100222/full/4631011a.html

Second I also cut out this part because it wasn't a proton:

-- The particle was traveling very close to the speed of light — assuming the particle was a proton, its speed was only about 1.5 femtometers (quadrillionths of a meter) per second less than the speed of light, translating to a speed of approximately 0.999 999 999 999 999 999 999 9951c. At that speed, in a year-long race between a photon and the particle, the particle would fall behind only 46 nanometers, or 0.15 femtoseconds (1.5×10 s); or one centimeter every 220,000 years.

The speed of the particle, if it was a proton, is so high that it would experience relativistic time dilation by a factor of about 320 billion. At that rate, the particle could have traveled for the entire duration of the universe's existence while experiencing a bit less than sixteen days of subjective time. --

Michel_sharp (talk) 22:31, 21 June 2015 (UTC+01:00)

I don't think one study's claim that some UHE cosmic rays might be iron nuclei is sufficient to warrant a rewrite of the article. Would you consider reverting those changes and adding a note of reference to this article as an alternative hypothesis instead? Bobathon71 (talk) 21:17, 21 June 2015 (UTC)

Looking at recent reviews such as http://arxiv.org/abs/1101.4256 and http://arxiv.org/abs/1403.2967 it seems that the iron nucleus hypothesis has merit but is far from being established as fact. If the article is to be rewritten as if this cosmic ray is not a proton, note that the calculation in the sentence beginning "The effective energy..." is no longer correct. Bobathon71 (talk) 12:50, 22 June 2015 (UTC)

Wait a minute

It is slower by 1.5 fm/s, but would only be behind 0.15 fm after a full year? There is a problem here. Tazerdadog (talk) 04:00, 27 August 2012 (UTC)

0.15 fs, not 0.15 fm. The bigger problem is the "year-long" race. A year in what frame of reference? Certainly not relative to the particle -- the particle would observe light traveling at the speed of light. I guess it is relative to a staionary observer. -- Schapel (talk) 14:23, 13 November 2012 (UTC)

The detected kinetic energy was relative to the Detector; or, in other words, the Particle's velocity, v, was relative to the Detector's frame of reference. Suppose the Year Long Race commences as the Photon and the Oh-My-God-Particle whizz past the Detector. On the passage of one year, as reckoned from within the Detector's frame, the Photon and the OMGP will have receded to two different distances from the Detector. Of course it doesn't have to be relative to the Detector. It can be any frame of reference relative to which the OMGP has its characteristic velocity. — Preceding unsigned comment added by 24.223.130.60 (talk) 00:20, 13 May 2014 (UTC)

So does that mean that if this particle hit you, it would be like getting hit by a baseball going 60mph? You'd like stagger or fall over for no apparent reason? If not, why not? Would you spontaneously human combust? lol :) This particle is the Oh-My-Devil particle. Dkelly1966 (talk) 16:03, 21 June 2013 (UTC)

What could be the source of this thing? Kortoso (talk) 22:31, 21 October 2014 (UTC)

One of the sources named is Cygnus X-3 and if it hit's you, you do not feel anything. These particles travel at a large fraction of he speed of light. It needs more time to impart kinetic energy than is available. Compare it to a bullet flying into a bunch of cotton-balls. Kleuske (talk) 12:51, 22 October 2014 (UTC)

Wait, so it would just pass through you? Hdjensofjfnen (Is something wrong?) 00:21, 23 February 2016 (UTC)

AFAIK, yes. In fact,you may be hit with high energy cosmic rays on a daily basis, without noticing. Kleuske (talk) 11:33, 23 February 2016 (UTC)

Planck Energy

There wasn't a source for the fraction of the Planck energy: 3×10/1.22×10=2.46×10. Both Plank Energy and the energy of the particle in question are well sourced. Expressing that as a fraction is a routine calculation. I haven't reverted since a) i'm not that sure how meaningful such a fraction is and b) WP:CALC seems to refer to original research. Any opinions? Kleuske (talk) 09:24, 30 July 2014 (UTC)

Doesn't a photon travel X light-years in X years?

" it would take 220,000 years for the photon to gain a 1 centimetre lead, and the particles will have travelled approximately 86,664,000,000,000,000 kilometers, about 9,160.4 light-years. " so wouldn't the particles have traveled about 220000ly?

159.92.27.130 (talk) 00:22, 28 February 2016 (UTC)

By definition it does. Where the numbers come from is unclear to me, but they obfuscate more than they explain, so I've deleted the claim. Kleuske (talk) 11:47, 28 February 2016 (UTC)

1. Bird, D. J. (March 1995). "Detection of a cosmic ray with measured energy well beyond the expected spectral cutoff due to cosmic microwave radiation". Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 441, no. 1, p. 144-150. Retrieved February 14, 2014.
2. J. Walker (January 4, 1994). "The Oh-My-God Particle". Fourmilab.