Talk:Astronomical unit/Archive 3

Archive 1

Archive 2

Archive 3

Cleanup of "Examples" section

I think it's time to clean up the "examples" table, and intend to delete a number of entries. Notably:

• Earth's circumference. Value irrelevant to understanding AU.
• Lagrangian point - imprecise term and irrelevant.
• Ceres - I think four planetary orbits (Mercury, Venus, Earth, Mars) are sufficient. I'd be willing to trim those down too.
• Jupiter - Ditto.
• Betelguese - Completely irrelevant for describing the AU. In this case, it's referring to Betelguese's diameter.
• NML Cygni - ditto.
• UY Scuti - ditto
• Saturn - see Ceres.
• Uranus - see Ceres.
• Neptune - see Ceres.
• Pluto - see Ceres.
• New Horizons - changing distance, and irrelevant to understanding AU.
• Eris (twice) - see Ceres.
• 90377 Sedna (twice) - see Ceres.
• Voyager 1 - see New Horizons.
• Scattered disk - obscure term, not necessary for understanding AU.
• Hills Cloud (twice) - Obscure term, not necessary for understanding AU.
• Hill/Roche sphere. See Hills Cloud.
• Sirius - we already have one star's distance (Proxima) listed in AU. Don't need a second.
• Betelguese (2nd instance) - see Sirius.

This will leave us with a table looking like roughly like below (references removed here to avoid cluttering talk page). I could be persuaded to remove more entries, like the seperate entries for start and end of Kuiper belt.

Object	Length or distance (AU)	Range	Comment and reference point	Refs
Light-second	0.002	–	distance light travels in one second	–
Lunar distance	0.0026	–	average distance from Earth (which the Apollo missions took about 3 days to travel)	–
Solar radius	0.005	–	radius of the Sun (695500 km, 432450 mi, a hundred times the radius of Earth or ten times the average radius of Jupiter)	–
Light-minute	0.12	–	distance light travels in one minute	–
Mercury	0.39	–	average distance from the Sun	–
Venus	0.72	–	average distance from the Sun	–
Earth	1.00	–	average distance of Earth's orbit from the Sun (sunlight travels for 8 minutes and 19 seconds before reaching Earth)	–
Mars	1.52	–	average distance from the Sun	–
Light-hour	7.2	–	distance light travels in one hour	–
Kuiper belt	30	–	begins at roughly that distance from the Sun
Kuiper belt	50	± 3	ends at that distance from the Sun	–
Light-day	173	–	distance light travels in one day	–
Light-year	63241	–	distance light travels in one Julian year (365.25 days)	–
Oort cloud	75000	± 25000	distance of the outer limit of Oort cloud from the Sun (estimated, corresponds to 1.2 light-years)	–
Parsec	206265	–	one parsec (The parsec is defined in terms of the astronomical unit, is used to measure distances beyond the scope of the Solar System and is about 3.26 light-years.)
Proxima Centauri	268000	± 126	distance to the nearest star to the Solar System	–
Galactic Centre	1700000000	–	distance from the Sun to the centre of the Milky Way	–
Note: figures in this table are generally rounded, estimates, often rough estimates, and may considerably differ from other sources. Table also includes other units of length for comparison.

Any objections before I boldly clean that up? Tarl N. (discuss) 22:25, 25 May 2018 (UTC)

It's been a couple of days. I'll be bold. Revert when ready, Mr. Gridley. Tarl N. (discuss) 00:38, 28 May 2018 (UTC)

I've re-inserted Voyager 1 and Voyager 2, the most distant active space probes, so the examples relate to what space exploration is capable of. I omitted Pioneer 10 because it's inactive and in any case, Voyager 2 will overtake it in a few years. Because it's meant to show what space exploration is capable of, I suggest the distances should be no longer updated after these probes are inactive and out of contact. I suggest their entries are replaced whenever some future probe exceeds their distance.  :-) Philh-591 (talk) 16:42, 7 December 2019 (UTC)

Manual of Style

Might I suggest that the Wikipedia Manual of Style, which recommends AU as the abbreviation/symbol for the astronomical unit, be updated to conform with current practice, which is to use au. This was recommended by the IAU in 2012 and is now adopted by leading professional journals such as MNRAS, ApJ, AJ, etc. There is no point Wikipedia persisting with an obsolete abbreviation. Skeptic2 (talk) 07:26, 30 October 2016 (UTC)

I agree that au is a better symbol than AU, and have argued for it before, but at that time there was a majority in favour of AU. Consensus can change though. Any other views? Dondervogel 2 (talk) 17:18, 30 October 2016 (UTC)

Just goes to show that the majority is not always right! Skeptic2 (talk) 20:46, 31 October 2016 (UTC)

Sure, but being right is not enough if we can't convince the others. The main choice was between AU and au, and while au is standard, it can sometimes take decades for a new standard to take hold. I would have preferred au, I'm OK with AU if applied uniformly, which it is.

I can think of a case when an international standard name (and symbol) was defined In 1998, but this standard is not considered acceptable by Luddite WP editors. Dondervogel 2 (talk) 22:10, 1 November 2016 (UTC)

NO! Wikipedia is an encyclopedia and its basis is to be encyclopedic, not consensual. It doesn't matter if a lot of users want to write meter as 'mt' instead of 'm', you cannot because the International System of Units decided so and that's the rule. It is not the Wikipedia Community that decides international standards, but the organizations meant for this. We have to use au, because so was decided internationally. A discussion can be done only if there is not a international official standard. SkZ (talk) 20:44, 8 May 2018 (UTC)

Well said. I concur. Skeptic2 (talk) 21:25, 8 May 2018 (UTC)

Long ago, I commented:

The 2012 IAU RESOLUTION B2 on the re-definition of the astronomical unit of length, recommends "that the unique symbol “au” be used for the astronomical unit." It looks like we've got a difference between the IAU (2012) recommendation and the BIPM (2006) report. I suspect the BIPM and the IAU will sort this out, but for the moment we probably should let both stand with the more recent IAU recommendation getting some priority. --SteveMcCluskey (talk) 17:43, 11 May 2013 (UTC)

The 2014 Supplement to the eighth edition of the BIPM brochure on The Internatioal System of Units and the draft ninth edition (forthcoming 2019) follow IAU practice, citing IAU resolution B2, 2012 and giving the abbreviation as au. With the principal international organization on weights and measures and the principal international organization on astronomy having sorted things out, Wikipedia should follow along. --SteveMcCluskey (talk) 02:03, 9 May 2018 (UTC)

SteveMcCluskey, that's enough to convince me. If you start an RFC at Wikipedia talk:Manual of Style/Dates and numbers I will support the change. Jc3s5h (talk) 14:22, 9 May 2018 (UTC)

Jc3s5h, Thanks for the suggestion, I've opened a discussion at their talk page. Feel free to chime in.--SteveMcCluskey (talk) 20:05, 9 May 2018 (UTC)

Good to see the RFC closed[1] and WP:MOSNUM improved to "astronomical unit / au (not A.U., ua) / The preferred option is au. Articles that already use AU may switch to au or continue with AU". 79.73.245.34 (talk) 09:43, 2 July 2018 (UTC)

For the purposes of this article, the change to au happened explicitly with the 2012 change in definition from using GM to a specific number of meters, which is at least relevant. MikeyNolan (talk) 06:45, 29 August 2019 (UTC)

au or AU in this article

In view of the recent agreement at MOS:NUM to make au the preferred alternative to AU in Wikipedia, we now have a basis to reopen the discussion on the format to use in this article

Guidelines on specific units

Group	Name	Symbol	Comment
Length, Speed	astronomical unit	au (not A.U., ua)	The preferred option is au. Articles that already use AU may switch to au or continue with AU; seek consensus on the talk page.

I favor changing to au in view of its widespread acceptance by standards agencies and astronomical journals and its preferred status in Wikipedia MOS. Comments and other opinions are welcome. --SteveMcCluskey (talk) 02:49, 13 July 2018 (UTC)

I agree. Skeptic2 (talk) 11:28, 14 July 2018 (UTC)

I also agree, and have continued the process of conversion started by MikeyNolan. The conversion still needs completing but I ran out of time. Dondervogel 2 (talk) 06:41, 29 August 2019 (UTC)

I have changed the entries on the main planets and some comet-related ones, but there is still a lot more to do! Skeptic2 (talk) 13:52, 29 August 2019 (UTC)

Except that Tom.Reding has now reverted them... And tells me that he has no intention of reinstating them, despite my request. Skeptic2 (talk) 21:46, 29 August 2019 (UTC)

I agree it would be best to switch wholesale, but the mosnum advice is to seek consensus on the talk page of each and every article. That's a laborious process :( Have you tried raising in at WP:Astronomy? Dondervogel 2 (talk) 08:57, 30 August 2019 (UTC)

I think editor SkZ hit the nail on the head in his comment from May 2018 above: it’s not about consensus, because the decision has been made by the international standards authorities. The official abbreviation is au. That decision has been adopted by the main professional publishers, and Wikipedia should follow suit. All the appearances of AU in Wikipedia will have to be changed to au eventually. Why some editors should want to be hold-outs I don’t know. Skeptic2 (talk) 11:02, 30 August 2019 (UTC)

We've had this discussion. Looking above, it looks like you have participated as far back as 2016. The MOS states that articles may continue to use AU. On any given page you want to change, you must seek consensus on doing so. I suspect you simply went and made a bunch of changes, and got reverted because it looked like you were ignoring the MOS (which it appears you were, you seem to have not bothered to ask, just went and made changes). The point of that caveat is that making mass changes to articles all over wikipedia is disruptive, and there is no pressing need. In any given article you spot that you think needs changing, initiate a discussion on the talk page. Per MOS, do not simply go and make massive changes assuming you have consensus already. You don't. Tarl N. (discuss) 17:24, 30 August 2019 (UTC)

AU has been the norm for many years, and it is only in the last few years the au is becoming more common. The transition should be gradual and not disruptive.-- Kheider (talk) 22:36, 30 August 2019 (UTC)

Actually it needs someone to write a bot to do it all in one go. It must be confusing to users to find Wikipedia still using an outdated convention. Skeptic2 (talk) 00:20, 31 August 2019 (UTC)

@Skeptic2: WP:DEADHORSE.   ~ Tom.Reding (talk ⋅dgaf)  01:17, 31 August 2019 (UTC)

And WP:CIVIL while we're at it.   ~ Tom.Reding (talk ⋅dgaf)  01:18, 31 August 2019 (UTC)

Discussion reopened in 2021

@Dondervogel 2: opened this again with a recent edit. From my quick look, "au" was the one form that was not used in this article; it has a mix of AU and AU. WP:MOSNUM explicitly allows AU, which (as has been discussed ad nauseum), is the form that is most widely used in the astronomical literature (despite style guides, the research journals continue to use mostly AU, and the textbook I pulled off the top of my shelf (Carrol & Ostlie, An Introduction to Modern Astrophysics, 2017, p. 25) also uses AU, as I think do most textbooks. The only thing I see that has changed since the extended discussion in 2015 in which the consensus was in favour of AU is that it's been another six years and common usage has continued to ignore the IAU and journal recommendations that a handful of editors use to say "au" is proper. —Alex (Ashill | talk | contribs) 00:49, 14 May 2021 (UTC)

@Ashill: First, the symbol preferred by WP:MOSNUM is ‘au’, not ‘AU’. Second, the version you had at least three occurrences of ‘au’. Third, the version you seem to favour is an incoherent mishmash of au, AU and AU. Dondervogel 2 (talk) 08:19, 14 May 2021 (UTC)

I don't prefer the current mishmash; I simply restored the status quo for discussion rather than imposing my preferred version.

First, where is the consensus for WP:MOSNUM preferring "au"? The last discussion there I see is from 2018, and there is no conclusion to that discussion; I didn't know until now that WP:MOSNUM had been updated to prefer au.

I do not recall ever seeing AU anywhere, so I don't think using that makes sense (and frankly question why it's even mentioned in the article as a useful styling, but whatever).

I don't even recall encountering au anywhere except going to look as a consequence of discussions here; it's the recommendation by the IAU but not one I've seen followed much and definitely not one used in any textbook I recall or any journal paper I've read except when I go looking for it as part of this discussion.

—Alex (Ashill | talk | contribs) 16:58, 14 May 2021 (UTC)

The edit was made on 30 June 2018. Dondervogel 2 (talk) 18:03, 14 May 2021 (UTC)

We seem to agree that AU should not be used so I have replaced that symbol with au, as required by WP:MOSNUM. We still have an unsightly combination of au and AU. The obvious solution is to replace AU with au. I think it is time to make that change. Dondervogel 2 (talk) 17:23, 3 July 2021 (UTC)

Articles currently using AU should be left alone. There is no reason to create conflict. -- Kheider (talk) 19:14, 3 July 2021 (UTC)

@Kheider: Who is creating conflict? This article had a confusing mix of au, AU and AU. No one was defending AU so I removed that variant, and now we are left with a confusing mix of au and AU. Where do we go from here? Dondervogel 2 (talk) 19:19, 3 July 2021 (UTC)

I think we have to ask the traditionalists, as I would call them, to drop their opposition to the update. Then see if someone can produce a bot that will make a global change throughout Wikipedia. I don’t see the need for a page-by-page consensus, any more than you would need a consensus to change cgs units to MKS. The IAU must be dismayed that Wikipedia still uses the old symbol. The update is long overdue.Skeptic2 (talk) 10:49, 4 July 2021 (UTC)

I agree – the update should have been implemented years ago. AstroLynx (talk) 11:10, 4 July 2021 (UTC)

As the Minor Planet Center and other still use AU, there is no reason Wikipedia should be forcing a standard on existing articles. -- Kheider (talk) 12:37, 4 July 2021 (UTC)

Attempt at clarification

This discussion is not about whether MOSNUM should read as it does (anyone wishing to change the guideline can raise this at WT:MOSNUM), but about how to interpret the present wording. The present wording advises use of au, unless an article already uses AU (in which case consensus is to be sought). This article ought to be WP's flagship article on the astronomical unit, and contains a mixture of AU and au, a situation MOSNUM does not anticipate. In principle I see 3 possible actions (for the article Astronomical unit):

1. Harmonise on the traditional symbol (AU)
2. Harmonise on the preferred symbol (au)
3. Do nothing, leaving the present mixture of au and AU
4. Change the lead to say: The astronomical unit (symbol: au often traditionally written as AU or AU)

I ask fellow editors:

• Have I missed any important options?
• If not, which of these do you prefer, and why?

Dondervogel 2 (talk) 13:05, 4 July 2021 (UTC)

I vote for Option 2, i.e. use the internationally agreed symbol throughout. The change will have to be made eventually, and the current mix of old and new is unsatisfactory. Skeptic2 (talk) 14:59, 4 July 2021 (UTC)

I too prefer Option 2. Options 1 and 3 run against the spirit of MOSNUM. Dondervogel 2 (talk) 15:29, 4 July 2021 (UTC)

Option 2 for me too for the reasons given above. AstroLynx (talk) 15:42, 4 July 2021 (UTC)

This is NOT the appreciate place to have such a vote that affects all of Wikipedia as there simply are not enough participants. Take it to a wider venue. -- Kheider (talk) 15:57, 4 July 2021 (UTC)

Comment The question is about the article Astronomical unit and this is the talk page for that article. Dondervogel 2 (talk) 16:28, 4 July 2021 (UTC)

I added a parenthetical remark, just in case that wasn't clear to editors. Dondervogel 2 (talk) 16:31, 4 July 2021 (UTC)

I prefer option 4 as it accommodates the numerous sources that still use the more traditional AU. I am ok with the infobox being simplified. -- Kheider (talk) 17:52, 4 July 2021 (UTC)

I've just noticed the article does not use AU, and hasn't done for some time, at least since 13 May. Only au and AU have been used since then. This means the choice is between AU (Option 1), au (Option 2), and a mixture of those two symbols. The mixture would require reverting some of my most recent edits (which I will do myself if that is the consensus outcome). Dondervogel 2 (talk) 18:17, 4 July 2021 (UTC)

I'd prefer "au", which is the more common form I see in publications. I've seen the smallcaps form, but it's relatively rare. Tarl N. (discuss) 18:25, 4 July 2021 (UTC)

A Commons file used on this page or its Wikidata item has been nominated for deletion

The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for deletion:

• International System of Units Logo.png

Participate in the deletion discussion at the nomination page. —Community Tech bot (talk) 22:38, 7 January 2022 (UTC)