Wikipedia:Good article reassessment/Metric system/1

Metric system

 * • [//en.wikipedia.org/w/index.php?title=Wikipedia:Good_article_reassessment/Metric_system/1&action=watch Watch article reassessment page] • Most recent review
 * Result: Article cleaned up by XOR and CC. Many thanks to them. AirshipJungleman29 (talk) 15:37, 11 July 2023 (UTC)

GA from 2013. Article looks to have a lot of uncited material such as among other uncited sections and statements. Onegreatjoke (talk) 17:22, 14 June 2023 (UTC)
 * "In the SI, the standard metre is defined as exactly 1⁄299792458 of the distance that light travels in a second. The realisation of the metre depends in turn on precise realisation of the second. There are both astronomical observation methods and laboratory measurement methods that are used to realise units of the standard metre. Because the speed of light is now exactly defined in terms of the metre, more precise measurement of the speed of light does not result in a more accurate figure for its velocity in standard units, but rather a more accurate definition of the metre. The accuracy of the measured speed of light is considered to be within 1 m/s, and the realisation of the metre is within about 3 parts in 1000000000, or a relative accuracy of 3×10−9. The kilogram was originally defined as the mass of one cubic decimetre of water at 4 °C, standardized as the mass of a man-made artefact of platinum–iridium held in a laboratory in France, which was used until a new definition was introduced in May 2019. Replicas made in 1879 at the time of the artefact's fabrication and distributed to signatories of the Metre Convention serve as de facto standards of mass in those countries. Additional replicas have been fabricated since as additional countries have joined the convention. The replicas were subject to periodic validation by comparison to the original, called the IPK. It became apparent that either the IPK or the replicas or both were deteriorating, and are no longer comparable: they had diverged by 50 μg since fabrication, so figuratively, the accuracy of the kilogram was no better than 5 parts in a hundred million or a relative accuracy of 5×10−8. The accepted redefinition of SI base units replaced the IPK with an exact definition of the Planck constant as expressed in SI units, which defines the kilogram in terms of fundamental constants.


 * Upon a first (quick) read, everything that is not explicitly cited can probably be footnoted by copying over the appropriate references from the articles on individual units, speed of light, etc. XOR&#39;easter (talk) 19:18, 15 June 2023 (UTC)
 * OK, I've started doing this. I've yet to find anything in the article which is not what I'd call "standard lore", i.e., the sort of stuff that is covered one way or another in many books and that scientists pick up by osmosis. It might take me a while to find the time to go through the whole page (thanks to a big cleanup job), so if anyone would like to swoop in and finish the task first, that'd be fine with me. XOR&#39;easter (talk) 01:50, 18 June 2023 (UTC)


 * Yes, it looks as if there are about a dozen chunks of text that need citing, and sources should not be far to seek given the various main articles on the subject. The article is tidily written and it just needs citing up so it should be a no-brainer save really. It's not my cup of tea but if this doesn't get done in reasonable time (I'd say there was no hurry) then ping me and I'll look at it. Chiswick Chap (talk) 15:12, 1 July 2023 (UTC)
 * The OpenStax college textbooks seem generally pretty good for the basics, like the subject of this article. I just added College Physics to fill in one of the cn tags; it could probably be reused elsewhere in the article, too. XOR&#39;easter (talk) 21:09, 2 July 2023 (UTC)
 * How's it going ? AirshipJungleman29 (talk) 23:18, 9 July 2023 (UTC)
 * There are half a dozen cn tags yet to fill in. I've been taking them in small steps as I find the time. XOR&#39;easter (talk) 23:41, 9 July 2023 (UTC)
 * I've filled in half a dozen tags, so with luck we're about there now. Chiswick Chap (talk) 12:36, 10 July 2023 (UTC)