Talk:Cosmic ray

Commnents probably outdated

Most of the commnents here are by far too old and probably outdated. Any Admin being able to do this is urgently asked to archive posts older than 10 years. 2A02:8108:9640:AC3:806:38BB:9468:B371 (talk) 07:07, 5 June 2021 (UTC) Marietta Balau should at least be mentioned!

https://en.wikipedia.org/wiki/Marietta_Blau — Preceding unsigned comment added by 47.152.242.42 (talk) 00:54, 10 June 2023 (UTC)

Rates in figure

The rates in the first figure "Cosmic ray flux versus particle energy" created by Sven Lafebre seem to be wrong comparing with the table in the section "Cosmic-ray flux". The table with the rates seems to be right regarding to this link: https://www.auger.org/index.php/edu-outreach/faq#section5. These should be the right rates:

From particle energy (eV)	To particle energy (eV)	Particle rate
1×109	1×1012	1×104 m−2s−1
1×1012	1×1016	1 m−2s−1
1×1016	1×1019	1 m−2yr−1
1×1019	5×1019 (see Greisen–Zatsepin–Kuzmin limit)	1 km−2yr−1

-- Sonnenyeti (talk) 09:12, 5 September 2017 (UTC)

HZE ions?

why doesn't this article or even the link to the article HZE ions actually say what HZE stands for?Eman320 (talk) 20:52, 24 March 2015 (UTC)

Edit Lede to reflect breakthrough new data

Because the Fermi orbital observatory supports gathering data of a range and quality not available before, Science Magazine (2013-02-15) has announced that there is now a solid explanation for the nature and origin of cosmic rays.

These new results, and side reporting that the AAAS' leading scientific journal considers conclusive, seems to obsolete much of the WP article's speculation and reporting of alternative explanations.

Much work remains, I've only edited the Lede and a little of the into thereafter.

It's exciting to see controversies that have consumed the careers of platoons of scientists suddenly resolve as new ranges of data arrive. This has led some historians of science to suggest that technology drives observation which in turn shatters old theories.

Others are more cynical: "Science progresses one funeral at a time" - suggesting that old partisans will never be convinced by newly evidenced arguments. Let's see if edit wars break out here.

GreggEdwards (talk) 10:09, 15 February 2013 (UTC)

It's premature to call such a preliminary report conclusive. They found the spectra they were looking for from just two supernovas and this is results from just one research group. I'd want verification from other scientists and good bit more data before drawing such sweeping conclusions. And the fact that some cosmic rays may come from supernovas doesn't mean that all do; this research doesn't address that question at all. Publishing in Science, rather than a respectable astronomy or astrophysics journal, also makes me skeptical of the results. Let's wait to see how this plays out before rewriting the whole article. --Mark viking (talk) 14:35, 27 February 2013 (UTC)

By that logic any paper ever published in Science, Nature, or any all-science journal should be considered "flawed" in some way. This is wrong, and discoveries as great as that of the origin of (some) cosmic rays does deserve attention from a broader community of scientists. More minor discoveries, such as those of yet another exoplanet, could be published in a dedicated astrophysics journal but I see no reason why the current result should be questionable.

At the same time, I agree that just because cosmic rays originate in supernovae, these origins are not necessarily confined to those events, and other explanations should thus be mentioned. Wer900 • talk 01:09, 28 February 2013 (UTC)

It could indeed be a great discovery; the point I was making is that I think it is too soon to tell. My dim view of Science magazine betrays my physics background and the particular physics culture I was steeped in. In that culture, publishing a physics paper in Science was like publishing it in the New York Times--done to gain attention rather than to be put to the test by one's peers. Science and Nature are more mainstream for other scientific disciplines like biology. I do think Science, Nature, et. al., are good journals, just not for physics/astronomy publication. --Mark viking (talk) 01:48, 28 February 2013 (UTC)

Yes, so let us write the lede to avoid recentism and say that a recent study has found evidence of enough neutral pions being made in supernovas (including those really big ones that that produce gamma ray bursts) to account for most of galactic cosmic rays. Most people already think that's where most of them come from. But surely black holes, including the supermassive blackholes in active galactic centers ALSO make some cosmic ray particles. And nobody has come up with a way that 50 J cosmic rays (see Oh-My-God particle) can be made by any single event, including a supernova. SBHarris 03:23, 28 February 2013 (UTC)

This sounds good to me. --Mark viking (talk) 04:22, 28 February 2013 (UTC)

GA Review

This review is transcluded from Talk:Cosmic ray/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: StringTheory11 (talk • contrib) 03:11, 1 March 2013 (UTC)

I will review. StringTheory11 (t • c) 03:11, 1 March 2013 (UTC)

Note: put the "Reviewer" line above the line and made some adjustments, so the bot can identify who the reviewer is for the GAN page. (Hope I've got it right.) BlueMoonset (talk) 03:21, 1 March 2013 (UTC)

Awesome; thanks! StringTheory11 (t • c) 03:24, 1 March 2013 (UTC)

Some preliminary things to do:

• Refs 42, 46, and 54, appear to be dead.
• The "History of Cosmic Rays" link and the "NOAA FTP" link appear to be dead.
• Make sure every paragraph has at least one ref.
• If there is not a ref at the end of a paragraph, all text after the last ref of the paragraph should be obvious stuff.
• Write the "sources of cosmic rays" section.
• Make sure that there is no text squished between images, and that all images are small enough.
• Expand the "research and experiments" section to include prose on some of the most important experiments.
• What is the point of the "references" section? All the refs appear to be in the "notes section".
• Trim the external links section to include only the most important links (4 or 5 is a good number).

StringTheory11 (t • c) 03:24, 1 March 2013 (UTC)

I've actually put the article on hold for now. Do keep reviewing, but I feel that I should work on this article a bit more following your recommendations before this article is once again actively reviewed. Wer900 • talk 05:31, 1 March 2013 (UTC)

Wer900, just so you know: it isn't for you to put the review on hold, it's completely up to the reviewer to decide, and the review takes care of it if so. (Right now, the status is "onreview", not "onhold".) Similarly, the reviewer can decide how long a hold should last, and can end the review if she or he feels the article is unlikely to be ready to be listed as a good article in a reasonable amount of time. I have removed your "on hold" template from the top of this page; it isn't how reviews are put on hold anyway. BlueMoonset (talk) 01:37, 2 March 2013 (UTC)

Ok, Wer900, send me a message on my talk page when you want me to resume. StringTheory11 (t • c) 02:25, 2 March 2013 (UTC)

• It's been a month since the above. Is there any hope of the review being resumed soon? If not, it should probably be closed. BlueMoonset (talk) 23:52, 1 April 2013 (UTC)

• You could review it, if you think yourself able. Wer900 • talk 03:51, 2 April 2013 (UTC)

• No, I'll leave that to StringTheory11. I gather that the go-ahead has been given, and StringTheory11 should be starting shortly. BlueMoonset (talk) 08:24, 2 April 2013 (UTC)

Ok, I'll resume the review.

• Many paragraphs need a ref. Each para needs at least one ref, and every fact (unless it is something like "the sky is blue" needs a ref).
• In the "research and experiments" section, I would include some more prose on the most important experiments, followed by the listing of the remaining ones.
• Some of the changes from above still need to be implemented.

Overall, I see no problems with clarity, deepness to the topic, nor prose. Once these are fixed, I think it can pass GA. StringTheory11 (t • c) 03:38, 17 April 2013 (UTC)

My apologies for missing this on my watchlist. I'll make these changes shortly. Wer900 • talk 22:35, 29 April 2013 (UTC)

• There appears to have been some work on April 29, then nothing, and no response here. Since it's been another two weeks, I'd like to make a suggestion to StringTheory11: set a hard deadline for the changes you feel the article needs to be done. If they're done by that date, pass the article; if not, fail it. This article is by far the longest-running GA review, at over 70 days. That's just too long. BlueMoonset (talk) 03:46, 14 May 2013 (UTC)

The above changes were implemented long ago; I just wasn't able to strike them out then. Wer900 • talk 22:22, 14 May 2013 (UTC)

Oh, awesome! I'm not watching the article, just this page. I'll take another look at the article again before the end fo the weekend. StringTheory11 (t • c) 23:56, 16 May 2013 (UTC)

OK, so there's a lot of stuff that still isn't referenced, so I can't pass the GA review. As BlueMoonset notes above, it's just been too long since the GA review started for me to pass this time, so I have to fail it. Once the issues are fixed, feel free to renominate it. StringTheory11 (t • c) 20:08, 19 May 2013 (UTC)

I added an "Origins" section. I nominated the article for GA but it's clear that there is still some work to be done on it. We should put the nomination on hold while this section is being fleshed out. However, I do still feel that the Fermi results should be mentioned in the lede, as that has really been the main attraction to cosmic rays that has come in the last several years. It's not a super-rapidly-changing field. Wer900 • talk 05:43, 28 February 2013 (UTC)

Nuclear Plants? - a source of 'artificial cosmic rays' ??

One of the tables lists nuclear plants as a source of artificial cosmic rays, among others that are terrestrial sources. While the production does produce a variety of products, if up to standards of most first world nations it should not increase exposure to the surrounding population as it indicates. Nuclear plants are highly contained and do not release any radiation under normal circumstances(Complete Melt Downs being the obvious exception).

I don't quite remember the exact stats for coal plants, but is that perchance the radiation exposure for what a coal power plant releases onto the countryside? I don't have any of my books handy to double check at this time, was more looking through some wikipedia sections to see what was said. — Preceding unsigned comment added by Soulbourne (talk • contribs) 10:34, 10 June 2013 (UTC)

In Our Time as a source.

I was disappointed this hadn't got to GA status. The In our Time program on cosmic rays for 16 May 2013 could provide many of the missing references. Profs Carolin Crawford, Alan Watson, and Tim Greenshaw covered much of the same ground as this article, albeit at a lower level. However it does have a number of factual one liners which could be used as references. JRPG (talk) 22:21, 12 June 2013 (UTC)

Units of measure

I have a problem with the following paragraph:

Cosmic rays attract great interest practically, due to the damage they inflict on microelectronics and life outside the protection of an atmosphere and magnetic field, and scientifically, because the energies of the most energetic ultra-high-energy cosmic rays (UHECRs) have been observed to approach 3 × 10^20 eV, about 40 million times the energy of particles accelerated by the Large Hadron Collider. At 50 J, the highest-energy ultra-high-energy cosmic rays have energies comparable to the kinetic energy of a 90-kilometre-per-hour (56 mph) baseball. As a result of these discoveries, there has been interest in investigating cosmic rays of even greater energies. Most cosmic rays, however, do not have such extreme energies; the energy distribution of cosmic rays peaks at 0.3 gigaelectronvolts (4.8×10^−11 J).

The first measure is in eV, then there is J(oules), and finally a fraction of gigaelectronvolts (converted to Joules parenthetically). Can we get someone to edit for consistency?

The parenthetical conversion is nice, but I find it difficult to try and use 0.3Gev=4.8x10^-11J as a way to compare the values.

WesT (talk) 19:54, 25 October 2013 (UTC)

NPOV of section "Postulated role in climate change"

The section on the “Postulated role in climate change” seems to me very much not a WP:NPOV. The worst is the 97% figure which is taken out of context. Yes 97% of those that have written at least 20 climate related peer reviewed articles suggest they believe that “anthropogenic greenhouse gases have been responsible for “most” of the “unequivocal” warming of the Earth's average global temperature over the second half of the 20th century.” But this says nothing about if those scientists believe cosmic rays can affect the climate. You could defiantly point to that survey to say 97% of climate scientists do not believe that “most” of the warming was from GCR’s, but you can’t say that 97% believe cosmic rays have no impact on the climate at all (at least based on that survey). Even more likely is that they just don't know exactly what the impact of GCR's are on the climate, but they think that it is less then "most" of the warming.

I think it can be rewritten in such a way that it doesn’t suggest that it is the accepted theory but still remains neutral in its evaluation. Specifically there are four scientific questions, first is can galactic cosmic rays induce aerosol formation, second can these aerosols grow sufficiently to form cloud condensing nuclei (“CCN”), third do these CCN lead to additional clouds formed, lastly are enough clouds formed to have a significant impact on global climate. Just about everyone (from Svensmark to skepticalscience.com to the IPCC) agrees that these four questions will need to be answered yes to demonstrate that GCR affect the climate.

As to the first question, because of the CLOUD experiment at CERN their nature article appears to answer the question as yes, and I think at this point the scientific consensus is that GCR can create aerosols. The answer to the second question is far more controversial Svensmark published a paper in 2013 claiming that the experiment he conducted showed the answer to this second question was yes, but clearly this has not yet become the scientific consensus.

Also why are we still referencing the 2007 IPCC report, why not use the 2013 AR5, which says there is medium evidence that cosmic ray-ionization mechanism is too weak to be climatically significant (the IPCC answer to the 4th question above).

For a great example Wikipedia article that I think deals well with both this issue and the controversy look at the Wikipedia article on Henrik Svensmark.

Obsidi (talk) 00:12, 13 February 2014 (UTC)

To me the section has a rather insinuating tone: it links him to "the popular culture movement that denies the scientific consensus" and (I think) accuses Svensmark of data manipulation. His work has been published in peer-reviewed journals like "Physical Review Letters" or "Astronomy and Geophysics", of course peer review is not perfect. The "one man against the world" tone is more suitable for a newspaper than an encyclopedia. I'll modify the article a bit. JuhoSchultz (talk) 19:23, 8 July 2015 (UTC)

Right now the section has too much redundancy. It could do with a balanced rewrite. Praemonitus (talk) 20:18, 8 July 2015 (UTC)

The rewrite by Sweart1 in August 2015 have gone uncontested, and appear to have brought neutrality back to the section. Based on this, as well as the absence of any follow-up discussion, it appears that the removal criteria for the NPOV tag have been met, and I will remove it. Doc cromwell (talk) 04:36, 7 April 2016 (UTC)

Gamma-ray burst noncorrelation

There is a serious misinterpretation of a cited article in the section on sources of cosmic rays. The current version states "However, no correlation was found between the incidence of gamma-ray bursts and cosmic rays, causing the authors to set a lower limit of 10⁻⁶ erg cm⁻² on the flux of 1 GeV-1 TeV cosmic rays from gamma-ray bursts.". This is obviously wrong: observing no cosmic rays from gamma-ray bursts allows one to set an *upper* limit on their cosmic-ray flux, not a lower limit. The number is also wrong; see below.

The relevant section of the linked article is on page 38, right column. Figure 4 (bottom) shows the upper limits placed on the cosmic-ray flux from different gamma-ray bursts, as a function of their position in the sky as seen from the observatory. The lowest such limit, quoted later in the text, is 3.4 × 10^-6 erg cm⁻²; that is, there is at least one gamma-ray burst that did not exceed this cosmic-ray flux. The text further notes that theoretical models of cosmic-ray production in gamma-ray bursts generally predict fluxes below 10^-6 erg cm⁻²; this is where the incorrect number comes from.

I'm editing the article to correct this point, with the summary referring to this comment for clarification. (There's also a bug in the description of the citation, which I don't have the know-how to fix.)

References

— Preceding unsigned comment added by 194.66.18.6 (talk) 15:11, 2 February 2015‎ (UTC)

Gamma Ray absorption

The following statement appears in the text:

In 1929, Bothe and Kolhörster discovered charged cosmic-ray particles that could penetrate 4.1 cm of gold. Charged particles of such high energy could not possibly be produced by photons from Millikan's proposed interstellar fusion process.

I haven't been able to find a citation for this, and am a little skeptical about its veracity. Apparently, gamma ray attenuation when passing through a material is determined by the absorption law, which follows an exponential decay based on the distance travelled.[1] Hence the assertion seems invalid as some small fraction of the gamma ray flux would always get through. Praemonitus (talk) 22:12, 29 April 2015 (UTC)

Possible error in section on detection regarding Cerenkov radiation

I am not an expert on this subject but I think there may be an error in the section on detection.

The explanation of the Cerenkov telescope says the Cerenkov radiation from cosmic rays hitting the atmosphere is in the form of gamma rays. I suspect this is wrong for the following reasons:

1 Wikipedia articles on VERITAS and IACT Cerenkov telescopes both seem to imply that the radiation being detected is visible light, (just possibly infra-red or utlra-violet) with mention of mirrors and photomultipliers.

2 The article states that the telescopes can operate only on moonless nights, implying that visible light interferes with operation.

3 All my previous reading about Cerenkov radiation in other contexts has always implied that it is visible light.

My extremely limited knowledge on this subject suggests that there may have been confusion between the Cerenkov radiation and the gamma rays produced when a cosmic ray strikes a molecule in the atmosphere as described earlier in the article.

ColinBrownWD35NY (talk) 14:49, 25 August 2015 (UTC)

Assessment comment from 2007

The comment(s) below were originally left at Talk:Cosmic ray/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

Comment(s)

Press [show] to view →

As a cosmic ray physicist, I rated this article as 'Start'. The article has a fair amount of information but it has major flaws. The information is unstructured and cluttered. IMO, better would be (introduction) Detection Classification (with sources, acceleration mechanisms...) History Influences Effects on life (space travel, ambient...) Effects on weather Cosmic rays and fiction Much of the information is irrelevant or overdetailed, while some of the basics are missing: interesting secondary effects like lightning and cloud formation are mentioned, but there's no accurate description of (possible) cosmic ray sources or acceleration mechanisms. There are strong points as well: Good historical review. References seem to be in order. Connections to everyday life. The Mid-priority range was judged by the topics already assessed. I hope this is useful. I'll see if I get round to doing some stuff. I don't want to be too drastic all by my myself, though. --Svenlafe 01:30, 5 January 2007 (UTC)

Last edited at 01:30, 5 January 2007 (UTC). Substituted at 12:19, 29 April 2016 (UTC)

1942?

Can anyone substantiate the cosmic ray claim from 1942? I am about to pull it unless corroboration is forthcoming, but I see no mention here. LandOfTheBlind (talk) 18:22, 4 December 2016 (UTC)

No mention of role in mass-extinction

Having skimmed and searched the page for mention, I can see none of the contended role of cosmic rays in mass-extinction? This seems a bit of a glaring absence. Three links can be found here, straight off a search engine

• http://news.nationalgeographic.com/news/2007/04/070420-extinctions.html
• http://www.space.com/33379-supernova-explosions-earth-life-mass-extinction.html
• http://www.livescience.com/49040-gamma-ray-burst-mass-extinction.html

LandOfTheBlind (talk) 13:49, 5 December 2016 (UTC)

Why is the truth being censored?

I entered the following: But in the interest of scientific rigor, it should be noted that all 97% consensus claims have been debunked, with many of their results attributed to cherry picking of the data (as in the Cook study).

References

It was reverted many times. I'd like to know why the truth is being censored.

Here's what some of the climatologists had to say about the Cook study:

=======================

Prof. Craig D. Idso: "That is not an accurate representation of my paper."

Dr. Nicola Scafetta: "Cook et al. (2013) is based on a strawman argument because it does not correctly define the IPCC AGW theory..."

Professor Nir J. Shaviv: "Nope... it is not an accurate representation."

Dr. Alain Carlin: "No, if Cook et al's paper classifies my paper... as "explicitly endorses AGW but does not quantify or minimize", nothing could be further from either my intent or the contents of my paper. I believe that there is sufficient evidence concerning misclassification that Cook et al's paper should be withdrawn by the authors and the data reanalyzed, preferably by less-biased reviewers."

Professor Nils-Axel Morner: "Certainly not correct and certainly misleading. My papers are strongly against AGW."

Professor Willie Soon: "This rating of 'no position on AGW by CO2' is nowhere accurate nor correct."

Professor Richard Tol: "7 out of 10 assessed papers were wrongly classified, another 112 were completely omitted! Of these, 111 (99%) were neutral. I think (their) data are a load of crap. I think (their) sampling strategy is a load of nonsense."

=======================

There are many, many more instances like the above quotes. The Popular Technology article definitively debunked ALL '97% consensus' claims.

In point of fact, the reference you cite for your '97% consensus' claim in the Cosmic Ray article: Anderegg, William R. L.; Prall, J. W.; Harold, J.; Schneider, S. H. (21 June 2010). "Expert credibility in climate change". Proceedings of the National Academy of Sciences of the United States of America. 107 (27): 12107–12109. Bibcode:2010PNAS..10712107A. doi:10.1073/pnas.1003187107. PMC 2901439Freely accessible. PMID 20566872. Retrieved 7 July 2013.

Is debunked via peer-reviewed articles not once: http://www.pnas.org/content/107/39/E151.full.pdf (Proceedings of the National Academy of Sciences, Volume 107, Number 39, September 2010) - Saffron J. O'Neilla, Max Boykoff

Not twice: http://www.pnas.org/content/107/47/E176.full.pdf (Proceedings of the National Academy of Sciences, Volume 107, Number 47, November 2010) - Jarle Aarstad

But THREE times: http://www.pnas.org/content/107/52/E188.full.pdf (Proceedings of the National Academy of Sciences, Volume 107, Number 52, December 2010) - Lawrence Bodenstein

The credibility of Wikipedia hinges upon the truth being told, regardless of political or religious leanings. Your religious belief in CO2-induced AGW may or may not be based upon knowledge of the field, but your attempt to censor the truth that there is no '97% consensus' can only be on a willful and knowing basis after the evidence of such has been presented, and therefore you harm Wikipedia's credibility.

Not only should you be ashamed of your behavior, but your administrator privileges should be revoked. People who act as you do are the reason Wikipedia is discounted as a credible and accurate source of information.

— Preceding unsigned comment added by 71.135.39.123 (talk) 17:14, 5 March 2017‎ (UTC)

All three of those PNAS citations are not peer reviewed articles, they are letters responding to a previous article. — Preceding unsigned comment added by SmallMossie (talk • contribs) 00:43, 26 June 2019 (UTC)

Marie Curie

I don't think it's accurate to say Marie Curie discovered radiation. Her work was extremely important, but in the history section the wording should probably be changed, or just dropped since she is not really part of the cosmic-ray story. — Preceding unsigned comment added by 73.97.30.208 (talk) 20:35, 17 October 2017 (UTC)

Correlation between Cosmic Rays and Ozone Depletion

According to Physics World:

Neil Harris of the European Ozone Research Coordinating Unit in Cambridge, UK, is not convinced. He told physicsworld.com that showing a statistical correlation is not enough to prove the validity of the cosmic-ray mechanism since there could be other causal factors varying throughout the solar cycle. In any case, he says, Lu is wrong to compare cosmic ray intensity against total ozone because measurements of the latter depend on the movement of ozone around the atmosphere as well as the actual disappearance of ozone. AlbertACJefferson (talk) 17:40, 29 August 2018 (UTC)

I agree, so I've removed the text. I think it's a quasi-nutty theory with little support. FWIW, it was added by anon ages ago ([2]) but the same anon also vandalised some other stuff ([3]) William M. Connolley (talk) 18:07, 29 August 2018 (UTC)

Extragalactic cosmic rays

In the section about the types of cosmic rays the article says: "Cosmic rays can be divided into two types, galactic cosmic rays (GCR) and extragalactic cosmic rays, i.e., high-energy particles originating outside the solar system," I think that the last part is wrong. Extragalactic means outside our Galaxy and not outside the solar system. — Preceding unsigned comment added by 2001:16B8:1E7C:4800:2DD4:15D:CF34:84B2 (talk) 12:34, 15 September 2019 (UTC)

Are the cosmic gamma rays considered cosmic rays

Are the cosmic (extra-solar) gamma rays considered cosmic rays ? The intro implies not. Later sections on energy suggest yes. Or, Are all gamma rays excluded from cosmic rays', or just the ones from GRB's ? Rod57 (talk) 10:29, 17 January 2020 (UTC)

About the reference for the IBM study on Ram flips by cosmic rays

At the moment the reference is "Scientific American (21 July 2008). <Solar Storms: Fast Facts>. Nature Publishing Group." that does not provide the primary source.

This does, that is the source would be McKee, W. R., McAdams, H. P., Smith, E. B., et al. "Cosmic Ray Neutron Induced Upsets as a Major Contributor to the Soft Error Rate of Current and Future Generation DRAMs" 1996 IEEE Annual International Reliability Physics, pp. 1-6, 1996.

--Pier4r (talk) 14:23, 3 May 2021 (UTC)

Difference between X-Rays and Gamma Rays technically not correct

This article says, regarding different types of electromagnetic radiation, they “are known by their common names, such as gamma rays or X-rays, depending on their photon energy.” Technically, at some point in recent decades, science decided that gamma rays are defined as electromagnetic radiation from nuclear transformations, which “typically” have higher photon energy than X-rays. This is also consistent with the way it is phrased in the Wikipedia article on gamma rays. So technically, this article is incorrect when it uses gamma rays and X-rays as examples of electromagnetic rays that are distinguished by their photon energy. Just saying. 2601:646:9B00:3BF0:9C63:C69B:D654:10FF (talk) 21:21, 13 June 2022 (UTC)

Archived

I was Bold and archived sections of excessive age. This included threads that were started in 2006-2010 but had a single reply as recent as 2021-2022 due to no constructive discussion continuing. The archive can be found here if any items need to be referred to or if this change needs to be undone. Thank you! King keudo (talk) 13:59, 17 October 2022 (UTC)

Note, I did not archive the GA assessment, in case items in said assessment still need to be addressed. Thank you! King keudo (talk) 14:05, 17 October 2022 (UTC)

Article issues and classification

The "Identification" subsection has an April 2015 "citation needed" tag. There are also several other paragraphs that are unsourced. The B-class criteria #1 states; The article is suitably referenced, with inline citations. It has reliable sources, and any important or controversial material which is likely to be challenged is cited. The article does not currently meet the criteria for B-class.

There are seventeen entries in the "External links" section. Three seems to be an acceptable number and of course, everyone has their favorite to add for four. The problem is that none is needed for article promotion.

• ELpoints #3) states: Links in the "External links" section should be kept to a minimum. A lack of external links or a small number of external links is not a reason to add external links.
• LINKFARM states: There is nothing wrong with adding one or more useful content-relevant links to the external links section of an article; however, excessive lists can dwarf articles and detract from the purpose of Wikipedia. On articles about topics with many fansites, for example, including a link to one major fansite may be appropriate.
• WP:ELMIN: Minimize the number of links. An August 2020 "excessive or inappropriate external links" tag has not received any attention so I will trim it down to three. -- Otr500 (talk) 04:25, 28 February 2023 (UTC)

Simple Questions: % of what, charge balance of earth, C-14 neutrons ?

I'm putting this question back, after it was archived, because it hasn't yet been answered. Eric Kvaalen (talk) 09:23, 7 June 2023 (UTC)

Do the percentages (e.g.,99% of the particles are protons) refer to numbers of particles, mass associated with a type of particle, or some other method? Does the 99% protons, 10% alpha particles, 1% elections mean the Earth is continuously getting more positively charged? Obviously this cannot be, so how is charge balance achieved? In the synthesis of carbon 14, where do the neutrons come from? They are not listed as primary or secondary cosmic particles, there must be some reaction that cosmic rays cause that produces them. Savoy rattler (talk) 07:17, 15 October 2011 (UTC)

Yeah, very good question. It would also mean that the objects that are the sources would be becoming more and more negatively charged! What is the explanation? Eric Kvaalen (talk) 17:12, 2 August 2021 (UTC)

@Savoy rattler: I think I may know the explanation. From the German article de:Marcel Schein and the reference Prof. Marcel Schein I understand that in the 1930s it was thought that cosmic rays were probably positrons and electrons, but Marcel Schein using high-altitude balloons found that there were not high-energy electrons or positrons, and therefore the cosmic rays (which were already known to be mostly positive) were probably protons. It's certainly possible that most cosmic rays are positively charged, because they go in every direction, so they're not transferring charge overall in any direction. The solar wind does contain electrons, but apparently not very high-energy. So the earth can simply attract solar wind electrons to neutralize the positivvely charged cosmic rays. I suppose the sources of the cosmic rays give off electrons as well as the sun, but they don't get accelerated to high energies. Eric Kvaalen (talk) 13:49, 14 August 2024 (UTC)

@Savoy rattler: I would add that the neutrons must be from the destruction of nuclei. If a 300-MeV cosmic ray (quite normal) hits a nitrogen or oxygen nucleus, it will smash it to "smithereens", sending all its nucleons flying apart. Even these will have enough energy to explode other nuclei, and so on. Eric Kvaalen (talk) 09:23, 7 June 2023 (UTC)

Collisions with electrons

Can someone tell us (and put into the article) what the chance is that a cosmic ray will collide with an electron before hitting any nucleus? This could give rise to particles that would then go on to hit other things. But the available energy would be at best about 1/2000 of the kinetic energy of the cosmic ray, so it wouldn't be as productive as when the collision is with a nucleus. Eric Kvaalen (talk) 14:42, 7 June 2023 (UTC)