Talk:Angstrom

message: If the unit angstrom is named after a person, why isn't it always capitalized like Watt, Newton, Joule, etc?--128.83.129.36 (talk) 16:30, 28 March 2008 (UTC)
replies: text: The units you mention are not capitalised.  They are spelled watt, newton and joule. Thunderbird2 (talk) 17:23, 28 March 2008 (UTC)
thread_title:  Capitalization 

message: I have a question about the statement that the Angstrom is obsolete.  The Angstrom is very much alive and well.  I don't think you mean to say that it is no longer used, but that could be explained better.  Do you mean that it changed when the meter changed?
AndyofVermont 03:14, 11 April 2007 (UTC)
thread_title: Obsolete?

message: How would you pronounce "angstrom" in Swedish? An IPA transcription might be useful. 128.12.20.195 05:19, 19 January 2006 (UTC)
replies: text: As it "might be called for", I will explain User:Ruhrjung that the Angstrom character resembles an Å but tends to be rendered more thinly and with a smaller circle above, just like the Watt W resembles a Latin W but is not identical to it. Perhaps User:Ruhrjung would like to check the Unicode standard? — Jor (Talk) 17:26, 26 Mar 2004 (UTC)
replies: text: Tat is not a "Unicode standard" for writing these symbols.  In fact, that section of Unicode is only included as an accomodation for interpreting things in some old non-Unicode code pages in certain East Asian languages, and it is not for current use in Unicode even in them.  The proper symbol for the angstrom is indeed the Swedish letter Å.  Gene Nygaard 01:18, 27 Jun 2005 (UTC)
thread_title:  Pronunciation of Angstrom 

message: Shouldn't it bother you guys that on this page it says that an angstrom is equal to both 10^-10 and 10^-12 meters?  —Preceding unsigned comment added by 70.122.216.197 (talk • contribs) 
:People who don't know what they are talking about bother me more.  Maybe you have difficulty understanding what 100×10−12 means?  Gene Nygaard 08:59, 8 December 2006 (UTC)
thread_title: 10<sup>-10</sup> or 10<sup>-12</sup>?

message: Why does it state that an angstrom is 0 LY?  I know that its really really close to 0 when compared to LY, but it would be inaccurate to actually state it is 0 LY, since its base unit is defined in distance light travels in an ammount of time anyways.
Also, why does the article give the measurement in 100 times an amount?  Why isn't it just a straight-up amount?  It seems that this has already caused confusion, and I don't see a reason for it to be that way.
:That was rediculous.  Not zero but about  ... but, of course, such a conversion is not necessary on the page. JIMp talk·cont 03:05, 1 July 2011 (UTC)
thread_title: Zero light-years?

message: Please take any requested moves to WP:RM and avoid unilateral actions. Regards, Asteriontalk 12:08, 3 March 2007 (UTC)
replies: text: By the way, I am not sure whether the tutorial on how to represent the symbol in computers is encyclopedic. Asteriontalk 12:10, 3 March 2007 (UTC)
replies: text: It may be encyclopædic but it still doesn't belong here. JIMp talk·cont 03:06, 1 July 2011 (UTC)
thread_title:  Page moves 

message: Right now the content related to the various articles relating to measurement seems to be rather indifferently handled. This is not good, because at least 45 or so are of a great deal of importance to Wikipedia, and are even regarded as Vital articles. On that basis, I am proposing a new project at Wikipedia:WikiProject Council/Proposals#Measurement to work with these articles, and the others that relate to the concepts of measurement. Any and all input in the proposed project, including indications of willingness to contribute to its work, would be greatly appreciated. Thank you for your attention. John Carter 20:50, 2 May 2007 (UTC)
thread_title: Proposed WikiProject

message: In the infobox at the top right of the page, the angstrom is related to the meter with the strange relation "100E-12 m". This is, in my view, an unusual (to say the least) combination of engineering and scientific notation. The limitation to powers of multiples of three is only ever used with letter prefixes, such as in "100 pm". Unless someone comes forward to defend this entry, I will change it to "1E-10 m" in a day or so, and accordingly for the nanometer. 149.217.1.6 08:58, 11 September 2007 (UTC)
replies: text: You mention engineering notation, so you should be quite well aware that your statement "The limitation to powers of multiples of three is only ever used with letter prefixes, such as in "100 pm"" is false. In fact, engineering notation is rarely used in conjunction with a symbol containing a prefix, except maybe with kg since kilograms are the SI base unit.  In other words, it might be either 100 E-12 m or 100×10−12 m using engineering notation, or 100 pm using prefixes, but not some combination such as  100×10−6 µm using both prefixes and engineering notation.  Gene Nygaard (talk) 20:36, 6 February 2008 (UTC)
thread_title: Bizarre mixed engineering/scientific notation

message: The article claims that the non-standard term micron is commonly used.  Is it?  Is this old term not being replaced by the standard SI term micrometre (or same term spelt another way)?  Heaps of Google hits, sure, but they mostly don't seem to refer to the unit.  Is it common?  Is it even still remembered?  AHD says "No longer in technical use." JIMp talk·cont 08:54, 11 June 2008 (UTC)
replies: text: AHD is wrong; micron is definitely in technical use (and it's not nonstandard, just non-SI; not the same thing at all). In my experience no one says micrometer, at least in EDA. SI fundamentalists make me tired. --Trovatore (talk) 03:05, 27 July 2008 (UTC)
thread_title:  How common is the term ''micron''? 

message: How many?
96.240.135.135 (talk) 20:50, 2 September 2008 (UTC)
thread_title: Angstroms in a Parsec?

message: From the IPA given i gather that it should be pronounced something like ongstrem? But does any English speaker outside of Scandinavia actually say it like that or do they use normal English rules to say it - something like /æŋstrɒm/? Given the argument that it is an English word as well, wouldn't it be correct to say the name of the unit with English orthography when speaking English? If so, then couldn't it be wrong to say it with Swedish pronunciation when speaking English? However I would pronounce the surname with the correct Swedish sounds even when speaking English. 83.146.13.57 (talk) 23:34, 25 April 2009 (UTC)
thread_title:  Pronunciation again 

message: Although it is wikistandard to upper case the first letter of a title, in this situation the reader may wonder which is correct usage. To display the title in lower clarifies this issue. I note that that lower casing the title itself was proposed in the recently approved RM. This not technically possible, but I did modify the display appropriately. Kauffner (talk) 14:59, 1 July 2011 (UTC)
replies: text: How does angstrom differ from ampere, kelvin, palaeontology or bicycle, none of which have the title displayed in lowercase? As for “reader[s who] wonder  which is correct usage”, the first sentence after the hatnote starts with “The angstrom”., duh. I'm reverting that. ― A. di M.​plé​dréachtaí 15:27, 1 July 2011 (UTC)
thread_title: Displaying lower case title

message: As a Swedish speaker, I find the name slightly curious.  Many common Swedish family names have the component "ström" (Bergström, Strömberg, etc; see also Swedish name) but "Ång-" is a weird one.  I would understand it to refer to steam, but perhaps there is a dialectal or regional word root with a different meaning?  As such, the name could be translated into "steam stream".  I guess this piece of trivia is not fit for the article text, but if you are reading this, enjoy (-:-- era (Talk | History) 10:50, 17 December 2012 (UTC)
replies: text: I've found this strange as well. I looked into it a little and it turns out Ångström's father and uncle, who were the first to use the name, were born in Ångebyn, Medelpad, just outside today's Ånge (and named after Ångan, a tributary to river Ljungan). 85.226.204.113 (talk) 07:07, 5 June 2015 (UTC)
thread_title:  Meaning of the name 

message: There is more to be said than just how to spell the name or the unit. Ångström was a reputable scientist and there is more to tell. For instance, in order to perform the accurate measurements he ordered a copy of the original meter bar from Paris. The problem was that the copy was some one cm too short (or too long, can't remember), introducing a systematic error in all measurements. This resulted in University of Uppsalas reputation being questioned. This was considered a very problematic back then for a university in operation since 1477. Several results not named after him were first obtained by him, for instance, (at least one of) Kirchoff's three laws. I'm afraid I don't have references, but this is what I've been told. The meter bar should still be there at the department of Physics and Astronomy. YohanN7 (talk) 13:49, 28 April 2014 (UTC)
replies: text: Bravo! I confess, I didn't believe you at all at first, because 19th-century metrologists worked to much smaller errors than one part in 100. But you're broadly right. The fine details are that Ångström was using a bar already held in Uppsala but had it checked against a Paris bar that was itself checked against the primary standard. Good idea - it was a little short. But the eminent metrologist who checked it reported a much greater error - I haven't tried to find out if his reasons for doing so were questioned. I've added a sentence and a reference to the article. And now, exhausted from all that hard work, I'll leave it to you to add the Kirchoff's laws material to Anders Jonas Ångström - WP:SOFIXIT! :) NebY (talk) 16:59, 28 April 2014 (UTC)
replies: text: Your edit looks very good. I'm afraid that all I have is (obviously!) vague and fading recollections of physics lectures in Uppsala. YohanN7 (talk) 16:06, 1 May 2014 (UTC)

text: I found a picture (of a painting), in the Swedish Wikipedia, and put it into the article. (I might be able to get my hands on a real photography as well ,not sure.) I also found out that Kirchoff's law of thermal radiation was discovered and published in 1852 by Ångström. We can thus let Kirchoff keep all of his so-called three laws, which I now believe are separate results, on his own. But being completely exhausted from putting in the image, I better rest a few days. YohanN7 (talk) 19:15, 3 May 2014 (UTC)
replies: text: Grand! I've put the infobox at the top - I think it takes priority. Good to see your idea of resting for a few days is to cite Gödel. :) NebY (talk) 19:40, 5 May 2014 (UTC)

text: I now put in the Absorption law of Ångström. I think I shall have to lie down for a moment or two. YohanN7 (talk) 15:36, 8 May 2014 (UTC)
thread_title:  Content 

message: The [Edit] tag on each paragraph is in the big title font and doesn't have the usual square brackets.  I have no idea how to fix this. 173.76.101.86 (talk)  —Preceding undated comment added 21:38, 5 March 2016 (UTC)
replies: text: That was strange. But it seems OK now - maybe just a server cache problem. NebY (talk) 23:31, 5 March 2016 (UTC)
thread_title:  Corrupted "[Edit]" Tag 

message: Substituted at 05:20, 13 May 2016 (UTC)
thread_title: Assessment comment

message: I was wondering why I was coming up with 1553164.117 wavelengths of the cadmium red-line per 10^10 angstroms (the so-called "Cadmium meter", per the 1907 IAU definition given as 6438.46963), while virtually all internet searches were coming up with "1553164.13". Later, I managed to trace a change in the article from 6438.4696 to 6438.46963 in an unsourced one-character edit by 146.115.127.198, all the way back to 2008.  I suspect that 6438.4696 (which yields 1553164.12459 per 10^10 (1907) angstroms) is correct (based on the printed publications which I have come across), and the error has since propagated to several other websites that have used Wikipedia as a reference.  Should this ten-year-old edit be reverted, or not? DWIII (talk) 14:42, 3 September 2018 (UTC)
thread_title:  1907 IAU definition of the Angstrom: Was it 6438.4696, or was it 6438.46963 (???) 

message: The name of the unit in English, for all practical purposes, is "angstrom", not "ångström". Just as the unit of current is "ampere" not "ampère", the unit of mag field is "oersted" not "Ørsted", and 1/1000 of a mm is a "micrometer", not a "μυκρόmeter".Units of measurement are given names for one purpose only: to make scientific communication easier and more reliable.  Not to stroke the ego of dead scientists, or of their countrymen.  That the name is based on their names should already be enough of an honor: if they were not dead, they surely would be pleased even if we don't spell their names like the Swedes or Poles or Mongols do. Demanding diacritics on the names of the units goes against that single purpose of unit names. Not only they are inconvenient, but having two names for a unit would be a source of totally pointless confusion (e.g. in searches). For the sake of productivity and comfort at work, in research or industry, we should not choose to use hard-to-type names, much less demand or suggest that others do.As explained in the article, although the NIST and IBWM use the spelling "ångström", they do that only in the list of deprecated units.  The vast majority of English texts use "angstrom"; and most English dictionaries (which are based on common usage) give that as the normal spelling, and may not even list "ångström" as a variant.So please, please, let's not give the spelling "ångström" a legitimacy that it definitely does not have, and does not deserve. --Jorge Stolfi (talk) 06:45, 9 March 2019 (UTC)
replies: text: Of course the names are given to honour the scientist too. Oxford says it spelled ångström too, therefore, it should be in the lead. The article was under the other title for three years without any complaints. Search machines knows how to convert from å to a or aa and so on, and the same "problem" occurs with meter vs. metre. Bring a source which says Ångström is outdated. Christian75 (talk) 14:25, 9 March 2019 (UTC)
replies: text: I beg to differ: units are not given names to honor scientists.  It is never "we need to honor حيان, let's name some unit after him", but rather "we need a good standard name for this unit, let's hear some suggestions".As you can see further up in this talk page (ca. 2011), the article was created as "angstrom", moved to "ångström" without discussion, moved back to "angstrom" as a result of official discussion, and has been there for 8 years.That discussion about the move cites plenty of evidence that the correct name of the unit in English is "angstrom", as recorded in authoritative dictionaries like Merriam-Webster, Collins, and even the Oxford Learners Dictionary; and that there is no authoritative support (or good reason) for giving  "ångström" as a valid alternative name.  Just as the unit names in English are "volt" not "volta", "farad" not "faraday", "oersted" not "ørsted", and "ampere", not "ampère". (By the way, even Italians call the unit "volt", not "volta".)And, again, having two supposedly valid names for a unit goes counter the very purpose of giving standard names to units.As for the OED, it is famous for collecting every meaning and spelling that has been used by someone since the 1600s...--Jorge Stolfi (talk) 02:58, 10 March 2019 (UTC)
thread_title:  Angstrom vs ångström, again (sigh) 

message: :::Oersted is the same as Ørsted, oe is the same letter as ø in Danish. The thread you mention start with 'Some textbooks write "angstrom" others "angström" and some "ångström"'. Examples with more than one spelling are: roentgen/röntgen, metre/meter,  - both are correct, Planck constant/Planck's constant, ... But it really doesn't matter what the spelling are for other words. Btw. I can give you a lots of sources saying units are named to honour the scientists, here is one . Christian75 (talk) 14:40, 10 March 2019 (UTC)
replies: text: If scientists had chosen to name the unit "orsted" in English, instead of "oersted", or "volta" instead of "volt", those would be their correct names.  Same if they had chosen "aangstroem" instead of "angstrom".  But they named the units "oersted", "volt", "angstrom" -- so those are their correct names.  "Orsted" and "ørsted" are not valid alternative spellings: they are just wrong spellings.</br>You missed my point.  Statues are created to honor scientists: they don't get set up by people saying "we need a statue here, let's hear suggestions for the subject". People say "we should set up  statue to honor this guy, let's hear suggestions for where to put it.".  But for unit names it is totally the other way around: scientists and technicians decide that they need a name for a unit of measurement, and they may eventually choose one that is based on the name of a scientist.  But not always: see for example erg, metre, liter, candela, barn, mole, ..."Meter" and "Metre" are not two alternative spellings of the unit.  The first is the only correct spelling in American English (AE), while the second is the only correct spelling in British Engish (BE) -- two distinct (although very similar) languages.  Some editors of scientific journals will even insist that the unit is spelled one way or the other, depending on where the journal is published -- no matter where the authors are from.  It would not make sense to have a separate Wikipedia for each of these two languages, so Wikipedia works around that fact by the rule that the creator (or first substantial contributor) to an article gets to choose whether it will be written in AE or BE; but, either way, spellings must be consistent throughout the article -- no waffling between "metre" and "meter"."Plank's constant" and "Plank constant" are not names of the unit in the sense that "angstrom" or "farad" are.  They are English phrases that refer to "the constant that was defined by Planck".  Thus it is correct, for example, to write "Ångström law of light scattering", or "Volta battery", or "Faraday cage"; and wrong to write "Angstrom law", "Volt battery" or "Farad cage"  -- because those words are the names of the persons, not the names of the things. (Although "Angstrom law" is such a common mistake that it may be considered correct by now...)All the best, --Jorge Stolfi (talk) 17:49, 10 March 2019 (UTC)
replies: text: As you wrote yourself, "IBWM and the NIST spell it as ångström" - Therefore, it should be in the first line in the wp:lead.  Christian75 (talk) 18:21, 10 March 2019 (UTC)
replies: text:  Well, that is no longer an argument since the 2019 edition does not mention the unit, in either spelling. --Jorge Stolfi (talk) 13:23, 21 November 2021 (UTC)
replies: text:  The four references used in the lead for ångstrøm still uses å. Christian75 (talk) 14:21, 21 November 2021 (UTC)
thread_title:  Angstrom vs ångström, again

message: When was the unit explicitly defined as a unit? Did Jonas define it as a unit, or did he just write "10−10 metre", "10−7 mm", or the like?And when was it named "angstrom"? Obviously it was not Jonas who chose that name... The article says "In 1892–1895, Albert A. Michelson defined the angstrom so that the red line of cadmium was equal to 6438.47 angstroms.[18]" However, the quoted text in [18] does not support that claim.  Rather it seems that Michelson just established the length of the meter in terms of wavelength of specific spectral lines. Or did he define the angstrom elsewhere in the same paper? --Jorge Stolfi (talk) 08:00, 21 November 2021 (UTC)
replies: text: According to Gross (2019) "Michelson invented an interferometer that substantially improved the precision of length measurements. This allowed him to define the ångström with respect to an atomic spectroscopic line, namely the red line of cadmium." Dondervogel 2 (talk) 08:46, 21 November 2021 (UTC)
replies: text:  Gross also says "[Jonas] introduced a unit length of 10−10 m, which was significant in accuracy without the need for fractional numbers."  The second part of the sentence leaves me wondering whether the first part can be taken literally. (Measuring things in 10−10 meters is not more accurate than measuring them in 10−9 meters; it was only more convenient for Jonas in that case, as it avoided fractions).So, did Jonas really propose a new unit of length for his tables, approximately 10−10 meters but in principle independent from the meter; or was his use of 10−10 meters just a typographically convenient ad-hoc choice? If the former, how did he call that unit? (Surely not "ångström"!)Is Gross just interpreting Michelson's results as improving the definition of the angstrom, rather than just proposing a better definition for the meter?Jonas died in 1874; was his name already being used for the unit when Michelson published his findings, only 18 years later?  Did Michelson himself define the unit and name it "ångström", or were the concept and word defined by someone else, earlier or later?  Was Jonas's son Knut, who worked in the same field as his father, involved in the naming somehow?Maybe Michelson wrote "Ångström's unit" — which of course is not the same as "the ångström"?The origin of the unit and of its name deserves be better clarified and documented. That quote from Michelson's article does not do that... --Jorge Stolfi (talk) 14:19, 21 November 2021 (UTC)
replies: text:  I searched the Michelson paper electronically for the string "Angstrom" and came up with nowt. This gives me the impression Michelson did not use that term. Dondervogel 2 (talk) 14:54, 21 November 2021 (UTC)
replies: text:  Thanks for the link!I can sort of read French, enough to understand the paper (and enjoy the "literary" way science was reported back then!). I flipped through the whole paper and did not see any reference to Jonas or his unit.What Michelson did was build an apparatus that, in a sequence of nine stages, would let him count the number of wavelengths of some monochromatic light between two parallel optical flats, with increasing separation ending with 1 meter. He did the experiment at the BIPM so he had access to the real meter standard bar.  The results he obtained with that apparatus (page 85) was "the final conclusion of this work is that the fundamental unit of the Metric System is represented by the following numbers of wavelengths of the three cadmium radiations, ... red radiations: 1 m = 1'553'163.5 λR; green radiations: 1'996'249.7 λV; blue radiations: 2'083'372.1 λB."I still don't see what was the connection between that and the angstrom, specifically.All the best,--Jorge Stolfi (talk) 11:42, 22 November 2021 (UTC)

text:   On the other hand, I found ONE reference to "angström" in This document, the proceedingd of the 7th General Conference on Weights and Measures, held in Paris in 1927.By that time the metre was still defined as the distance between two scratches on that platinum-iridium bar (and would be for another 40 years), but the BIPM was still quite conscious of the work by Michelson (and Fabry and Perot after him), and were seriously considering replacing that definition with one based on wavelengths of spectral lines.  In fact, they were already using Michelon's method, and thus (implicitly) the optical definition of the metre, to create secondary metre standards (quartz bars precisely 10 cm long) to be given to the standards bodies of member countries.On 1927-09-30, the commission discussed precisely that topic -- how to best redefine the metre in optical/spectral terms. In that session they use the angstrom without naming it, to specify spectral lines: "The experiments have led us to the five strongest lines of mercury (4358, 4916, 5461, 5770, 5791), to five lines chosen among those of neon (5852, 5882, ...". After a digression on details of the physical standards, the US delegate reports that the NBS urges the BIPM to adopt the spectral standard. The Japanese delegate concurs but asks for a moratorium while Prof Nagaoka in Tokyo finishes developing an improved cadmium vapor lamp. There is a request by a Mr. Kösters that the BIPM considers replacing the red line of cadmium by the yellow-green line of krypton. And then a Mr. Sears briefly objects that "the definition by angströms [sic] may threaten the Metric System, and it should be only temporary."  But then "Mr. Guillaume observed that the point is not to establish a true relationship between the meter and the wavelengths, but only the metric value of the latter, which may be modified by future experiments.". And the session ends, with the invitation for members to visit the BIPM laboratories.So that is an early reference for the unit, but it does not explain why and when it was defined.What the article needs is dates and references for the statement, currently unsourced, that "Ångström's chart and table of wavelengths in the solar spectrum became widely used in solar physics, which adopted the unit and named it after him. It subsequently spread to the rest of astronomical spectroscopy, atomic spectroscopy, and subsequently to other sciences that deal with atomic-scale structures".  That presumably is the real origin of the unit...All the best, --Jorge Stolfi (talk) 21:38, 22 November 2021 (UTC)
replies: text:  I found this quote from the OED, "1906 Trans. Internat. Union Solar Research I. viii. 230 Resolutions concerning standards of Wave-length. The wave-length of a suitable spectroscopic line shall be taken as the primary standard of wave-length. The number which defines the wave-length of this line shall be fixed permanently and thereby define the unit in which all wave-lengths are to be measured. This unit shall differ as little as possible from 10−10 metres and be called the Ångström." Dondervogel 2 (talk) 22:32, 22 November 2021 (UTC)
replies: text:  Wonderful, thanks! --Jorge Stolfi (talk) 23:14, 22 November 2021 (UTC)
thread_title:  When was the unit actually defined / named? 

message: Does the Unicode Consortium specify why U+212B ANGSTROM SIGN is deprecated? It seems to me that it would be preferable to use an "angstrom sign" character when denoting angstroms vs. just an accented letter. Then there is some semantic meaning there for screen readers (read it as "25 angstrom" instead of "25 A") or parsers to find.
(I have the same question about other deprecations, e.g. U+00B5 MICRO SIGN and U+2126 OHM SIGN and U+212A KELVIN SIGN. Why strip the semantic meaning?) 131.200.250.42 (talk) 18:35, 26 January 2023 (UTC)
thread_title:  Unicode symbol 

message: In the history section, there is text "In 1960, the metre itself was redefined in spectroscopic terms".  Should there not be additional text in that paragraph related to the current definition of the metre in terms of a fraction of the speed of light in a vacuum?  The article, as written, gives the incorrect impression that the metre continues to be defined in spectroscopic terms. 24.89.238.196 (talk) 16:07, 13 December 2023 (UTC)
replies: text: Yes, that would be an improvement. Feel free to boldly add some clarifying text. Dondervogel 2 (talk) 16:40, 13 December 2023 (UTC)
thread_title:  Definition of meter/metre