Talk:Ultra-high-energy cosmic ray

hyphens

The hyphens seemed more common, and "particle" lower-case seems more consistent with other particles, that's about as deep a reasoning as I have for this particular choice of name. Stan 06:29, 24 May 2004 (UTC)

BTW, this article demonstrates the evils of orphans; I remembered reading the first article, but had a terrible time finding it. Finally located it in the list of links to Salt Lake City. Stan 06:34, 24 May 2004 (UTC)

I've added a back-link from the GZK limit page, which should make it at least a little more accessible. --Christopher Thomas 07:02, 27 Feb 2005 (UTC)

It's a proton or a Micro Black Hole?

Would be a Micro black hole affected by the GZK limit? If not, here's your "best" suspect. --LF1975 (talk) 13:23, 21 February 2008 (UTC)

fastball?

I think the use of fastball gives this piece a look as if it was a joke, can it be re-written slightly more formally? Cokehabit 12:17, 24 Feb 2005 (UTC)

The article first describes it as 3 × 10²⁰ electronvolts, then 50 joules, and only after those formal measures does it compare it to a fastball. Since an average everyday joe off the street is unlikely to have an intuitive grasp of what those first two measures are like I think it's quite useful to have a comparison to an everyday event like this. Bryan 17:34, 7 May 2005 (UTC)

Are you talkign about a baseball batted fastball..? It is unclear for non americans. --Procrastinating@^talk2me 14:14, 28 January 2006 (UTC)

That is why fastball is linked, you can click on it and learn everything you ever wanted to know. :) Bryan 20:44, 28 January 2006 (UTC)

Comparing the energy fo UHECRs to a fastball is a somewhat standard practice, from what I've seen. In the same way a parsec is described as "about three light years," UHECRs are given a value that helps everyone understand the energies involved.

Scientific joke?

If I have to use the sentence above - in particle physics I am one of those "joe off the street". However scientist tend to publish scientific jokes sometimes. Is this event confirmed by an independent source or it happened only for a short period in 1991 and only in particular region of Utah? The whole story and the name suggest more towards a joke. A real particle will not be only dubbed but will also be named. All the sources I was able to find through Google sooner or later go to fourmilab.ch. This is a site of an entusiast and not a scientific magazine (as it says in the faq - fermilab is in the other hemisphere). So please provide some verifiable sources. TIA, Goldie (tell me) 18:17, 13 December 2005 (UTC)

I think the article mentions something about a proton or so, never heard of this one...gotta be a joke. In good meaning, i recommend to first get acquainted "how to search the internet" -> google it up. Slicky 09:55, 28 February 2006 (UTC)

This is not a new _type_ of particle. This is an ordinary particle (either a proton or an atomic nucleus) moving at speeds more extreme than we've seen just about anything move at. Particles _moving in this manner_ are (whimsically) dubbed "oh-my-god particles". Whimsical naming in this manner is common in science. A relatively recent example is the "sonic hedgehog" gene in fruit flies (one of a series of "hedgehog" genes, named because they produce spiky-looking development defects), but even the names of the quarks show this (up, down, strange, charm, bottom, and top, with the last two formerly called "beauty" and "truth"). --Christopher Thomas 06:08, 1 March 2006 (UTC)

Definitely NOT a joke. The name "Oh-My-God" particle was clearly meant to be humorous, but there really have been detections of ultra high energy cosmic rays, which scientists are currently studying. See, for instance:

http://www.sciencemag.org/cgi/content/full/288/5469/1147a

http://prola.aps.org/abstract/PRD/v34/i5/p1622_1?qid=75ae0aca4f0202c0&qseq=15&show=10

http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000092000015151101000001&idtype=cvips&gifs=yes

-- tim314

Though these might be valid sources they all require payment:

• "The content you requested requires a subscription to this site or Science Pay per Article purchase. "
• "Access to PROLA requires a subscription. PROLA subscriptions are separate from the subscriptions to the current content journals."
• "If you are not a registered subscriber but would like to purchase this article, use ..."

Regardless whether it would be 1p or 1 million, I do not want to pay just to verify a scientific joke (or a nickname). So I still consider the information unconfirmed. For some reasons I am calling the proton a proton, and am not considering it a different particle than the ... proton. If those scientific journals state just a high-energy proton was detected, this whole article ought to be merged as a section at Proton. -- Goldie (tell me) 17:28, 30 March 2006 (UTC)

Merging it with proton makes no sense. If it was merged anywhere, it would be with cosmic ray, because it _is_ an extreme example of a cosmic ray. As for the validity of the term, it's used by two of the sources cited in the article. Searching on Google for '"oh my god particle" -wikipedia' (to exclude references sourced from Wikipedia) gives 30,000 hits, indicating that the term is at minimum in common use by laymen and popular press. It appears to have entered popular press via an article written by John Walker discussing the U of Utah detection results. --Christopher Thomas 18:01, 30 March 2006 (UTC)

It still strikes me that people tend to rely on Google for counting but are reluctant to rely on counters for ... er, searching. Moreover using the stated ("oh my god particle" -wikipedia) search pattern produced here only 482 hits. As I am not accessing Google from China, the politically-correct filtering ought not to apply. It was even more weird to me that one of the first-page hits was derived from Wikipedia, was admitting the fact, but Google still have put it in the list. As few hundreds seemed to me still unmanageable I've ruled out "fourmilab" citations too and tried some one-by-one checks.

From what I've seen all references were rumors repeating the rumor (all that very famous John Walker article), and all was based on one-and-only observation! This article here is talking about "at least fifteen similar events confirming the phenomenon" but references do not show any!?! OTOH I've seen numerous theories about the particle type (an example: neutrino coliding to anti-neutrino and emitting some others) but the article is certain it "was" proton. If we look at Vela Incident article, it is talking about much easy verifyable matter but is employing much more cautious approach. Maybe some people understand the Oh My God Almighty and His particles much better than His creatures. -- Goldie (tell me) 11:48, 3 April 2006 (UTC)

Just did the search again. Still got "about 30,000" as the hit count. Try it yourself if you like. If you want more observations, follow the links in this article and elsewhere to the AGASA and Fly's Eye detector pages, and look through their publications. One particle with an energy of 3e+20 eV was detected, but many others in the 1e+19 range were also picked up. If you want to fix citations in the article to better reference these, go ahead, but I don't see a problem with the article as it presently stands. --Christopher Thomas 18:46, 3 April 2006 (UTC)

"might be" valid sources? What are you suggesting, that I'm trying to trick you? You are clearly not a practicing physicist, or you would recognize the journals Science and the Physical Review. These are some of the most well known journals of physics (follow the links to their Wikipedia article if you don't believe me.) I appologize for the fact that access to scientific journals generally isn't free, but there's nothing I can do about that. Anyone who does have a subscription (which should be basically any practicing physicist) can easily verify that they are legit. (And if you can even get to the Abstracts for free, it seems to me this should be proof enough, given that they are located at the well-known domains of major scientific journals.) Trust me, this is a real subject of study, and not a joke.

As for the claim that it should be merged with proton, I'm afraid you are missing the point. The "Oh-My-God particle" isn't significant because it's a new kind of particle. It's significant as an old kind of particle with a shockingly high energy. The phenomenon is what's significant (and thus worthy of its own article), not the kind of particle. Similarly, if an amazing flying horse were discovered, it would make sense to give it its own article, not merely a section under horses. Tim314 00:40, 7 April 2006 (UTC)

Incidentally, Goldie, you may be having trouble finding articles on the Oh-My-God particle because that name is mostly used in the media, not in technical journals. If you want to find real journal articles, you should search for terms like "Fly Eye", "cosmic ray", and "high energy".

There's a free pre-prints archive located at www.arxiv.org. Use the search function to find physics papers with "Fly Eye" in the abstract, and you'll see tons of references to high energy cosmic ray detections. The term "Oh-My-God particle" won't appear in most of them, because that's a non-technical term mainly used with the popular press, but that's what they're talking about. Likewise, real journal articles will refer to the "Higgs boson", not the "God particle" (as it's called in the media). Physicists tend to use cutesy names to get the general public to take some interest to what are actually rather esoteric topics. Tim314 01:05, 7 April 2006 (UTC)

Naming/Merging/Splitting

I think the term "Oh-My-God particle" should be dropped entirely from the article. I'm working in the field of high energy cosmic ray physics myself, and had never heard of the term prior to reading this Wikipedia article. -Svenlafe 17:29, 12 January 2007 (UTC)

Science has called it that at least twice in Eye Spies Highs in Cosmic Rays' Demise and Oh My God--It's a Real Particle. That seems like enough justification to keep the name. --Strait 18:49, 12 January 2007 (UTC)

All right, but the thing is that they are not the same as Ultra High Energy Cosmic Rays (UHECR) at all. UHECR are generally defined to have energies from around 10¹⁸ eV (cf. Nagano & Watson 2000, Fonseca 2003), well below the predicted GZK limit at around 5×10¹⁹–10²⁰ eV. The reason for the excitement about the cosmic ray discussed in the article is that its energy was above this theoretical limit. Most UHECR are 'well-behaving' cosmic rays, however, and even though their sources may be unclear, their very existence is not challenged, as is the case for cosmic rays above the GZK cut-off. So either the title of this article doesn't make sense, or its content is focusing on the wrong issues.

To resolve the situation, I suggest that we do one of the following:

1. Merge this article with the GZK article, since these topics are very closely related, and start a new article on UHECR;
2. Rename this article to 'Extremely High Energy Cosmic Ray' (see e.g. Bhattacharjee & Sigl 1998) and start a new article on UHECR;
3. Change the content of this article to reflect its title.

Furthermore, and this is an entirely different issue, we might think of changing the name UHECR to 'Extragalactic Cosmic Rays'. This would:

1. be analogous to the articles on solar cosmic rays and galactic cosmic rays, and
2. allow for a 'natural' classification based on physical cosmic ray sources instead of human-defined boundaries at random energies.

Any thoughts?

—Svenlafe 15:21, 15 January 2007 (UTC)

Your proposals all sound reasonable. I would lean towards keeping roughly the current organization, in which GZK is covered in one article and cosmic rays themselves are discussed in one or more other articles. --Strait 19:19, 15 January 2007 (UTC)

Deflection

"Because of its mass the Oh-My-God particle would have experienced very little influence from cosmic electromagnetic and gravitational fields..." and in the 1st external link "A particle with such energy would be deflected little by galactic magnetic fields" Is this a relativistic thing? because classically the force qv x B increases with velocity just as fast as the time spent in the field decreases with it, so deflections are the same for particles of all velocities. Thor2023 19:47, 14 December 2005 (UTC)

Yes —Preceding unsigned comment added by 68.232.50.153 (talk • contribs) on 01:17, 10 February 2006

To give something a bit less cryptic than anon's answer, consider that as the particle's speed approaches that of light from some observer's reference frame, its velocity doesn't change much (still approximately C), and its charge stays the same, but its mass increases drastically. Thus, the force is approximately the same, but the mass its trying to deflect grows, making the particle harder to deflect. --Christopher Thomas 04:13, 10 February 2006 (UTC)

46 nanometers?

Not true, light moves away from everything at a constant rate, no mater what its speed, its called the theory of relativity. I think that should be fixed. —Preceding unsigned comment added by 12.32.72.233 (talk • contribs)

True, actually, when measured from the perspective of the observer "at rest." The particle's perspective presumably remains consistent due to time dilation effects and such. Bryan 17:07, 30 March 2006 (UTC)

Special relativity does indeed ensure that views of the system from all inertial frames remain consistent. However, the value stated in the article seems to be in error. At 3e20 eV, a proton with a rest mass of 1e9 eV would be moving at about (1-3e-11) C, not the (1-5e-24) C stated. Which source was this value drawn from? --Christopher Thomas 18:07, 30 March 2006 (UTC)

This source: [1]. It shows the work used to get that figure. I'll paste it here, where's the error? Bryan 03:34, 31 March 2006 (UTC)

            M_0
   M  = ------------                                               [1]
                 v²
        Sqrt[1 - --]
                 c²

where M_0 is the particle's rest mass, 0, v is the particle's velocity, and c is the speed of light. Okay, we know that the Oh My God proton has a rest mass of about 1 GeV, and a total kinetic energy of 3×10^20 eV, so let's solve equation [1] for v, setting c to 1 to obtain velocity as a fraction of the speed of light:

v = Sqrt[m² - M_0²] / m

And thus, approximately:

v = 0.9999999999999999999999951 c

So taking 3×10^8 metres per second as the speed of light, we find that the particle was traveling 2.9999999999999999999999853×10^8 metres per second, thus 1.467×10^-15 metres per second slower than light--one and a half femtometres per second slower than light. If God's radar gun is slightly out of calibration, this puppy's gonna be doin' hard time for speeding. After traveling one light year, the particle would be only 0.15 femtoseconds--46 nanometres--behind a photon that left at the same time.

I think s/he was poitning out that the number of 46 nanometers is incorrect and should be removed entirely or stated something about if the theory of relativity didn't apply. Though while the later would be a unwise idea, they are options. Its true that light moves away from any other object at the speed of light no matter what its speed, even light itself moves away from light at the speed of light(crazy eh?). So my vote is to just remove the reference to being only 46 nanometers away and save us all one big headache. // Robert Maupin 02:00, 31 March 2006 (UTC)

But even moving at the speed of light there's still a point where the photon is only 46 nanometers away from the particle. 46 nanometers is about 1.5×10⁻¹⁶ light-seconds, so if the OMG particle arrives at a detector 1.5×10⁻¹⁶ seconds after the co-originating photon that means it was about 46 nanometers away when the photon hit. The theory of relativity is fine with this since it means that in the OMG particle's frame of reference the photon left it only 1.5×10⁻¹⁶ seconds ago (possibly less, does length contraction figure in here or just time dilation?). Bryan 03:34, 31 March 2006 (UTC)

Going over my recollections, it looks like I'd botched last night's calculations (used a first-order formula valid only at low speeds - whoops). I've gone through the correct version, which produces an answer that agrees with the one given by John Walker. My (current, hopefully correct) calculations are as follows, for anyone who wanted to see the steps JW omitted:

1. $M_{0}=1\cdot 10^{9}eV$
2. $M\approx 3\cdot 10^{20}eV$ (actually it's E + M0, but close enough)
3. ${\frac {M}{M_{0}}}={\sqrt {\frac {1}{1-{\frac {v^{2}}{C^{2}}}}}}$ (from SR; we both start with versions of this)
4. $\left({\frac {M}{M_{0}}}\right)^{2}={\frac {1}{1-{\frac {v^{2}}{C^{2}}}}}$
5. $\left({\frac {M_{0}}{M}}\right)^{2}=1-{\frac {v^{2}}{C^{2}}}$
6. ${\frac {v^{2}}{C^{2}}}=1-\left({\frac {M_{0}}{M}}\right)^{2}$
7. ${\frac {v}{C}}=\left[1-\left({\frac {M_{0}}{M}}\right)^{2}\right]^{\left({\frac {1}{2}}\right)}$ (this is equivalent to JW's ending formula)
8. ${\frac {v}{C}}\approx 1-\left({\frac {1}{2}}\right)\left({\frac {M_{0}}{M}}\right)^{2}$ (first-order expansion of square root of (1-x) is 1 - (1/2)x, valid because x is much smaller than 1 in this case)
9. ${\frac {v}{C}}\approx 1-0.5\left({\frac {1\cdot 10^{9}}{3\cdot 10^{20}}}\right)^{2}$
10. ${\frac {v}{C}}\approx 1-5.6\cdot 10^{-24}$

...And this is close enough to the 5e-24 value the article cites, which is consistent with a lag of about 50 nm.

So in summary, I goofed about the values. Sorry for the trouble.

Per the original thread, all of this is consistent with SR, and nobody who replied (including me) said otherwise. Part of the point of relativity is that all observers see light as moving at C, regardless of their motions with respect to each other. An observer on earth sees the particle travel for a year and arrive 50 nm behind a photon emitted at the same place and time. An observer sitting on the particle sees the photon receding at C, but sees a much shorter time between emission and detection, making the viewpoints consistent with each other. --Christopher Thomas 05:53, 31 March 2006 (UTC)

How fast, and what is it?

"The Oh-My-God particle is a proton with the energy of a slow-pitched baseball. And it's moving so fast that after travelling for a year, it would only be a few nanometers behind a photon travelling at the speed of light." [2] OK not an authoratative source, but can someone check the energy calculation? Rich Farmbrough 21:18 30 March 2006 (UTC).

Already done for distance (see above). One light-year is about 9e15 m, so at (1-3e-11) C, it'd lag the photon by about 300 km. The value given in press releases, (1-5e-24) C, gives about 50 nm (consistent with the stated distance), but I really don't see how they got that speed value (it's inconsistent with the value I get using special relativity). The energy, 3e20 eV, corresponds to about 50 J. A baseball (weighing about 0.14 kg) with that energy would be moving at about 27 m/s (about 60 mph). I'd like to see where that source got its information, as it looks like recycled press release or Wikipedia material at first glance. --Christopher Thomas 22:19, 30 March 2006 (UTC)

Update: I goofed with my original calculations. The value of (1-5e-24) C is correct, as is the 46 nm value. All other values in my previous response are correct. --Christopher Thomas 05:56, 31 March 2006 (UTC)

Pitch Speed

Personally I would like a little mroe accuracy in the speed of the basebal, there has bene alot of comments on this reference, elts see if we can clear it up and see what the speed of the baseball would be. Eg i the format of "A baseball pitched at a speed of X would..." it flows decently with the article and probably stop to many more comments being raised about it. -Robert Maupin 03:35, 12 April 2006 (UTC)

If a 150 g baseball had a kinetic energy of 50 J it would be moving about 25 m/s. Should I put that in? —Keenan Pepper 03:52, 12 April 2006 (UTC)

Sure ,it only helps.--Procrastinating@^talk2me 09:40, 12 April 2006 (UTC)

I'd found 140 g as the mass of a baseball, and got 27 m/s, and about 60 mph, as noted above. By all means put it in, but a mph conversion in parentheses is probably a good idea. --Christopher Thomas 15:46, 12 April 2006 (UTC)

Move to UHECR

Instead of having UHECR point to this article, could we move that around? "Oh-my-god" particle isn't exactly a recognized name in any literature I've read. —The preceding unsigned comment was added by 132.250.167.155 (talk • contribs) .

I agree. —Keenan Pepper 21:22, 6 June 2006 (UTC)

If it hit a human?

what would it happen if it had hit a human? at that energies it would create tremendous pressures on the skin wouldn't it? or would it just pass right through? - jak (talk) 16:01, 12 June 2006 (UTC)

Generally, a particle's chance of interacting with matter goes down as its energy goes up, so it would almost certainly just pass right through (along with the many, many other cosmic rays that pass through you every second). If it did interact with you, it would be imparting some of its energy onto an electron or other charged particle in your body, which would then cause a jet of secondary radiation, but you wouldn't notice this either (your chance of getting cancer would go up by some infinitesimally small amount). --Christopher Thomas 20:16, 12 June 2006 (UTC)

Christopher Thomas is right. I work at a gamma-ray spectroscopy lab and one of the things we constantly have to deal with is the tendency for high-energy gamma rays not to be completely absorbed by the detector, but to scatter away and leave only a small fraction of their energy, which is useless for our purposes. Even though one of the particles discussed in this article carries as much energy as a baseball, there's no way it could give any significant part of that energy to your body, so you'd never notice it. —Keenan Pepper 23:54, 12 June 2006 (UTC)

Ignoring science, it's funny to think about a guy getting blown back a few feet from a particle that nobody can see. It'd be as if an invisible man punched 'em. That's a frickin' crazy amount of energy. BirdValiant 03:31, 2 May 2007 (UTC)

I'd say it would be more like being shot by a very very tiny bullet... -- megA (talk) 10:42, 30 November 2009 (UTC)

A man was hit by a beam of accelerated particles in 1978, and survived, even if half of his face remained paralyzed: http://forgetomori.com/2008/science/hit-by-a-particle-accelerator-beam/ Gravitoweak (talk) 15:07, 27 November 2011 (UTC)

Mass

The article doesn't seem to mention its mass. Does anyone know what it is? Would I be right in thinking it's a proton or something of similar mass? raptor 11:14, 3 November 2006 (UTC)

If the OMG particle "hit" a person... It wouldn't or should I say the chances are very very low. Why? Due to the fact the OMG particle is traveling at the speed of light, or almost the speed of light, the chance of it hitting any particle (i.e. electron, proton, neutron) would be highly unlikely. Atoms "vibrate" at very high speeds in relation to the speed of light, however, any motion of the atom or particles would be inconsequential to a single atomic nuclei traveling at the speed of light. It is kind of like trying to shoot a bullet from earth and hit a bullet shot from the moon. This is hard for people to comprehend due to the extreme speeds and vast relative distances of an electron's orbit to the nuclei ratio.

Needs Work

The article talks about the so-called OMG particle, but has very little information about extremely high energy cosmic rays. It should discuss how these particles are studied, for examples with detectors that measure cherenkov flashes in the sky. It should mention how these particles produce a huge pancake of secondary radiation that can be measured and back-tracked by ground detectors. 71.112.95.176 01:28, 28 August 2007 (UTC)

more mysterious?

I think this article is misleading in light of the recent evidence from Pierre Auger Observatory. As I understand it, the evidence points to a potential explanation of the ultra high energy cosmic rays that does NOT violate the GZK bound. The article implies that single observations (like OMG particle) are sufficient evidence for the phenomenon being unexplainable using known physics. Atlytle 02:07, 16 November 2007 (UTC)

clarification required

The sentence "To a static observer, such a proton, traveling at [1 − (5×10−24)] times c, would fall only 46 nanometers behind a photon after one year." doesn't seem to make sense. Could you please explain the set up of this mind-experiment for the uninitiated? Plantsurfer (talk) 10:35, 7 March 2009 (UTC)

I think it means that in the static observer's frame of reference the proton is travelling at (1 − (5×10⁻²⁴))c or (1 − (5×10⁻²⁴)) light-years per year, whereas a photon travels 1 light-year in one year. So the difference in distance travelled in one year is 5×10⁻²⁴ light-years, which is about 47.3×10⁻⁹ metres. So, apart from the small error in precision (which I have fixed), the calculation in the article (and the source which it cites) is correct. Of course, in the frame of reference of the proton, things look very different - here the photon still travels at 1 light-year per year relative to the proton. Gandalf61 (talk) 13:53, 7 March 2009 (UTC)

Thanks, that's much better. Plantsurfer (talk) 14:53, 7 March 2009 (UTC)

Loop Quantum Gravity

Doesn't LQG explain ultra-high-energy comsmic rays? 74.14.111.238 (talk) 05:22, 29 July 2009 (UTC)

It's predicted to affect the behavior of UHECRs, and to affect light that's propagated large enough distances (from high-Z quasars), and to affect the cosmic microwave background (due to quantization artifacts in the pre-inflationary universe). The problem is that nobody's managed to unambiguously detect any of these signatures, and a related problem is that it's so far been very difficult to come up with predictions in the first place (tying the variables in which LQG is expressed to observable variables is apparently non-trivial and still an area of research).

Long story short, it might or might not explain them, and the impression I get is that it's too early to tell (otherwise we'd have experiments underway to conclusively prove or disprove various formulations of LQG by looking at the cosmic ray spectrum). --Christopher Thomas (talk) 07:29, 29 July 2009 (UTC)

Tracers

It's hard to tell which of the senses of "tracer" is intended in explaining the source of these cosmic rays.Unfree (talk) 18:19, 30 July 2009 (UTC)

Merger proposal

There are several possible explanations for these particles, but only Zevatron has its own very short article. Does it have enough notability beyond being a possible source of ultra-high-energy cosmic rays to warrant it's own article? And are there enough reliable sources to expand it beyond the stub it is now? I propose to merge it into this article and redirect Zevatron here. If the section gets too large we can always fork it off again. Smocking (talk) 17:57, 23 February 2010 (UTC)

• After some more digging it seems like Zevatron is just a nickname for any source of ultra-high-energy cosmic rays. Is that correct? In that case we should almost certainly just mention the nickname here and redirect Zevatron to this article. Smocking (talk) 18:07, 23 February 2010 (UTC)

From what I can tell from the journal article cited at Zevatron (edit | talk | history | protect | delete | links | watch | logs | views), the term was coined to refer to acceleration of particles within galactic jets. If this is the case, I'd be against a merger (if anything, it'd be best merged with relativistic jet). My vote would be for keeping it as a standalone stub for now.

You'd mentioned doing digging. What other sources did you find that use the term? These should probably be added to the reference section of zevatron. --Christopher Thomas (talk) 19:44, 23 February 2010 (UTC)

• These two articles [3] [4] and this book [5] seem to use the term in the "nickname" way. Or perhaps more precisely: for astrophysical sources as opposed to a result of new physics. The article cited at Zevatron does as well: In this Letter, we put forth the filamentary AGN jets as a promising candidate for the cosmic-ray Zevatron [6] (first page, right column, somewhere in the middle). Smocking (talk) 21:19, 23 February 2010 (UTC)

Fascinating reading; thanks for the links! I withdraw my objections to the merge. --Christopher Thomas (talk) 04:54, 24 February 2010 (UTC)

The article misleads people into thinking that ZeV is an accepted term for 10^21 eV. Zevatron is merely slang or at best jargon used by some ultra-high-energy cosmic ray researchers. The name does not derive from a unit of energy named ZeV. ZeV is derived from the slang term zevatron. A search for zevatron in Google revealed only the use of the term in this Wikipedia article and non physics uses such as a hair restorer advertisement. We missed a chance to simply delete the zevatron article for lack of notability or even notoriety. Now we should repair the damage the merger has done. - Fartherred (talk) 23:46, 2 April 2015 (UTC)

Bevatron is short for Billion-electron-volt synchrocyclotron.

Tevatron is short for Trillion-electron-volt (or tera-electron-volt) synchrocyclotron.

Zevatron must be short for the metric jargon of zetta-electron-volt synchrocyclotron because zillion is not scientific English. The Bevatron and Tevatron were actual working devices. The zevatron is just a metaphor relating to what people might have hypothetically called a synchrocyclotron working up to the energy of one electron charge moved through 10^21 volts. A Zetta-electron-volt is not an SI unit as far as I know. - Fartherred (talk) 00:53, 3 April 2015 (UTC)

The electronvolt is not an SI unit and hence a ZeV is not an SI unit, but there is nothing ambiguous, undefined or misleading about it as a unit. There seems to be nothing strange in the claim by the article about a zevatron (but whether it is notable and hence should be mentioned, I don't know). —Quondum 04:03, 3 April 2015 (UTC)

Things that should be mentioned in the article do not need to be notable. The topic of the article itself must be notable. Things mentioned should be understandable, and reliably sourced, and reflect the weight of expert opinion. MeV, GeV, TeV, PeV, and EeV redirect to Electronvolt where they are mentioned in the Energy comparison section. No one has come up with an energy comparison giving ordniary usage of ZeV. I suspect there is no ordinary usage of EeV or ZeV. It took me a little while to find that ZeV meant zetta-electronvolt. If the purpose of the article is to confuse readers with seldom used units that are unexplained, it succeeded in my case. I did not know whether to look for an English word or metric prefix to account for a z in the acronym. I will change the article to explain ZeV, then see what other editors do. - Fartherred (talk) 10:37, 5 April 2015 (UTC)

The problem of ultrahigh-energy cosmic rays has been completely solved

Archived self-published work.
The following discussion has been closed. Please do not modify it.
Mechanism-Revealed Physics (32/40) Completely solving the problem of ultrahigh-energy cosmic rays by discovering the mysterious source of ultrahigh-energy cosmic rays. The mysterious source of ultrahigh-energy cosmic rays has been widely recognized as one of the most fundamental mysteries in physics and astrophysics for several decades. The problem of ultrahigh-energy cosmic rays has been completely solved by identifying the mysterious source of ultrahigh-energy cosmic rays (P. 574 ~ 577, 5.9, Ch.5C, reference #1), with the newly established MRBHT* as fundamentally indispensable basis. (*Note, MRBHT = Mechanism-Revealed Black Hole Theory, P. 541 ~ 548, 5.5, Ch.5B, reference #1). Be clarified, in solving the problem of ultrahigh-energy cosmic rays, the concept and implication of black holes is based on MRBHT, rather than from current postulate-based black hole theory, i.e., mechanism-revealed black holes rather than postulate-based black holes. First of all and most of all, based on MRBHT, black holes and only black holes, due to their hugely massive nature, can have the ability to generate and emit such ultrahigh-energy cosmic rays, whereas all other ordinary astronomical objects (e.g., a variety of stars) do not have the ability to generate such ultrahigh-energy cosmic rays at all. Second, observational evidence shows that ultrahigh-energy cosmic rays have to originate from the Milky Way galaxy. Therefore, the combination of MRBHT and observational evidence determines the clear and solid conclusion: the black holes in the Milky Way galaxy are the source of ultrahigh-energy cosmic rays observed nearby Earth. In addition, five clues that are supportive of or consistent with the very conclusion are provided and analyzed (P. 574 ~ 577, 5.9, Ch.5C, reference #1). This conclusion is further consolidated by the fact that black holes are the source of gamma ray bursts from the comprehensive and systematic perspective (P. 567 ~ 574, 5.8, Ch.5C, reference #1), since gamma ray is one of the four common types of cosmic rays. The key to understanding the solving the problem of ultrahigh-energy cosmic rays: (i) considering the solving the problem of ultrahigh-energy cosmic rays together with the GZK limit in the famous GZK paradox, along with the reminding that the famous GZK paradox has been completely solved with the discovery of the source of ultrahigh-energy cosmic rays (P. 578 ~ 580, 5.10, Ch.5C, reference #1). (ii) As long as you have known the greatest equation in the history of science, which is Einstein’s famous mass-energy equation (E = mc2 or E0 = mc2), you will easily understand the solving the problem of ultrahigh-energy cosmic rays, because the law of object’s mass doing work (OMDW) (P. 93 ~ 109, Ch.1A, reference #1), which is the root of the solving the problem of ultrahigh-energy cosmic rays (P. 895, reference #2), has also revealed the mechanism behind the greatest equation (P. 114 ~ 118, Ch.1B, reference #1). (iii) The newly established MRBHT is the key to unlocking the mystery of ultrahigh-energy cosmic rays. Reference #1: 2009, Bingcheng Zhao, From Postulate-Based Modern Physics to Mechanism-Revealed Physics [Vol. 1(1/2)], ISBN: 978-1-4357-4913-9. Reference #2: 2009, Bingcheng Zhao, From Postulate-Based Modern Physics to Mechanism-Revealed Physics [Vol. 2(2/2)], ISBN: 978-1-4357-5033-3. Ph.D., Bingcheng Zhao, The author of “From Postulate-Based Modern Physics to Mechanism-Revealed Physics” 1401 NE Merman Dr. Apt. 703, Pullman, WA 99163 USA. Email: bczhao12@gmail.com or bzhao34@yahoo.com or bingcheng.zhao@gmail.com —Preceding unsigned comment added by 204.52.246.120 (talk) 19:11, 18 March 2010 (UTC)

Wikipedia is not the place to try to publish or popularize your own ideas. See WP:OR and WP:RS. --Christopher Thomas (talk) 19:17, 18 March 2010 (UTC)

Most Energetic Cosmic Rays from Graviton Acceleration

There is another possible source for the most energetic cosmic rays that should be listed. A significant and reasonable explanation for the origin of the most energetic cosmic rays could be based on gravitational acceleration. A reference could be given to www1.iwvisp.com/LA4Park/CosmicRays.txt , which serves as evidence that mentioning it would not be original research (as it is already published) on the Internet. Cosmic rays could have their kinetic energies increased by absorbing more attractive gravitons head-on than tail-on. That would apply if the speed of light is constant with respect to the frame containing the preponderance of particular-interacting-matter, given that gravity absorption evidence has been observed during some total solar eclipses. One can see en.wikipedia.org/wiki/Allais_effect and prd.aps.org/abstract/PRD/v62/i4/e041101 for examples of this absorption evidence. Alden E. Park (talk) 06:32, 7 October 2011 (UTC)

Proposed merge with Oh-My-God particle

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

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Content of Oh-My-God particle was forked from here, and people have been making half-hearted attempts to merge it back ever since. The content of 'Oh-My-God particle' is almost completely duplicated in the target, the 'name' has no real independent notability, and there is no potential for expansion. This should be merged back, with a redirect to the relevant section. Revent^talk 23:16, 31 July 2014 (UTC)

A quick scan on google-scholar shows that the term is used academically, especially in conjunction with the first to be detected. Like the Wow! signal, it seems to stand out enough to warrant a colloquialism. Kleuske (talk) 13:20, 1 August 2014 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Iron Nuclei

I've edit out the parts where it says that it's a proton, and replaced it with Iron Nuclei 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

Michel_sharp (talk) 23:10, 21 June 2015 (UTC+01:00)

10^20 ev corresponds to 7.7 * 10^23 kelvins

2* 10^20 ev/(3*Boltzmann's constant) = 7.7 * 10^23 kelvins

http://hyperphysics.phy-astr.gsu.edu/hbase/Astro/timlin.html

Just granpa (talk) 18:49, 8 December 2016 (UTC)

Relation with dark matter

It may be worth mentioning that the candidate dark matter particle mass -- 15 times the proton mass, or 1.4e10 eV -- has been excluded by later research. For example, Calmet & Kuipers use quantum gravity to show that a particle heavier than about 1e7 eV needs to either interact with photons (hence not dark) or decay on a timescale shorter than the age of the universe (hence not a candidate for dark matter in today's universe).

But I'm not sure how to work this in or if this is even appropriate so I'm just leaving this here. - CRGreathouse (t | c) 13:30, 12 October 2021 (UTC)

References

Extreme-energy cosmic ray

None of the sources refer to "Extreme-energy cosmic ray" by that term. The content related to that term does not match the article topic.

• This article is about UHECR "Astrophysicists ponder whether ultrahigh-energy particles really do come from the centre of galaxies." Hand, E (22 February 2010). "Cosmic-ray theory unravels". Nature. 463 (7284): 1011. doi:10.1038/4631011a. PMID 20182484.
• These are is about a hypothetical source, only one of many Honda, M.; Honda, Y. S. (2004). "Filamentary Jets as a Cosmic-Ray "Zevatron"". The Astrophysical Journal Letters. 617 (1): L37–L40. arXiv:astro-ph/0411101. Bibcode:2004ApJ...617L..37H. doi:10.1086/427067. S2CID 11338689. Osmanov, Z.; Mahajan, S.; Machabeli, G.; Chkheidze, N. (2014). "Extremely efficient Zevatron in rotating AGN magnetospheres". Monthly Notices of the Royal Astronomical Society. 445 (4): 4155–4160. arXiv:1404.3176. Bibcode:2014MNRAS.445.4155O. doi:10.1093/mnras/stu2042. S2CID 119195822.

I deleted the EECR section. Johnjbarton (talk) 22:30, 11 November 2024 (UTC)

Thank you for explaining the rationale for deletion here, John, since it again included one of my recent edits. 24.19.113.134 (talk) 23:03, 11 November 2024 (UTC)