Talk:Metric prefix

FOLDOC WP:PLAGIARISM checked ~Kvng (talk) 18:17, 4 January 2024 (UTC)

Why “ronna” and “quetta”?

In 2010 to 2015, someone suggests “xona” or “xenta” for 10²⁷, and for another prefix starting with x (e.g. “xono” or “xento”) for 10^-27, but not approved by SI (if they are approved, then possibly “wecra” for 10³⁰ and “wecro” for 10^-30), why in 2022 someone suggests “ronna” and “quetta” for 10²⁷ and 10³⁰ and “ronto” and “quecto” for 10^-27 and 10^-30 and approved immediately? 2402:7500:900:7FD6:9DF4:38BD:FA:9760 (talk) 23:45, 16 January 2023 (UTC)

The short answer is "why not". Essentially the SI would have accepted the first reasonable proposal where:

1. the words don't already exist in any language; preferably not at all, but at least not with meanings that would lead to confusion or controversy;
2. the words follow the existing pattern of -a for multipliers and -o for divisors;
3. the abbreviations don't conflict with any existing SI symbols (W is for Watt) or mathematical operators (x is easily confused with ×);
4. the abbreviations are matched pairs of upper & lower case for reciprocal factors

q/Q and r/R were the only letters available for abbreviations; then it was simply a matter of finding words to go with them.

Martin Kealey (talk) 21:02, 1 February 2023 (UTC)

Footnote on table at § List of SI prefixes

I noticed that the footnote at the end of the table says that the reference is the first reference, but in the article, it's the third. (Am QuickQuokka on a public computer; see my talk page) --46.10.223.203 (talk) 17:44, 12 June 2023 (UTC)

Abbreviation for "micro-"

I see "mc" being used in place of "μ" very commonly.

Can I use this? -sqrt(e^i pi): beep boop 07:50, 28 July 2023 (UTC)

Not on Wikipedia, except to explain where it is used. Dondervogel 2 (talk) 09:31, 28 July 2023 (UTC)

That is exactly what I meant. I will change the page then, to include this. -sqrt(e^i pi): beep boop 14:31, 30 July 2023 (UTC)

@Jc3s5h: @-sqrt(e^i pi): It's not out of ignorance, nor because of limitations of the keyboard (these are real, but circumvented in other ways). Instead, I believe 'mcg' is widely used by medics when prescribing drugs in tiny doses, because they fear 'μg' can result in an overdose if mis-read as 'mg'. I think this is worth mentioning if we can find a reference to back it up. Dondervogel 2 (talk) 16:04, 30 July 2023 (UTC)

Here's one example that Google found straight away. I'm sure you can find more. Dondervogel 2 (talk) 16:07, 30 July 2023 (UTC)

I consider this to be typical US government behavior. One agency, the FDA, just defies the law and NIST (which is part of the Commerce Department) by unilaterally proposing a change to SI rather than working with NIST or lawmakers to fix the problem. This is much the same as when law makers, President H. W. Bush, and NIST required the federal government to go metric as much as possible, and most federal agencies just ignored it. See Metrification in the United States.

An issue as far as what we should write is, what is the reliability of any article we find, and how much influence does it have in the field the article is addressed to? Is it just one researcher writing an article that sits on a shelf, or is the article actually affecting what practitioners do? I wouldn't automatically give weight to an article just because it was published by a government agency. Jc3s5h (talk) 16:29, 30 July 2023 (UTC)

This Scholar search found 23,800 hits. Dondervogel 2 (talk) 16:35, 30 July 2023 (UTC)

See also Microgram. Dondervogel 2 (talk) 16:37, 30 July 2023 (UTC)

If it there is an accepted exception to the SI style guide rule in common use in some situations, then surely that needs covering in the article, regardless of the reason for using it (ignorance, arrogance, safety concerns, typographical considerations, clarity, or whatever). -- DeFacto (talk). 17:16, 30 July 2023 (UTC)

The abbreviation "mcg" is in some situations an alternative for μg, but "mc" cannot be used in combination with other units. So "mc" is not a prefix, it has no place in this general article. The abbreviation "mcg" is mentioned specifically in the microgram article, that's enough. Ceinturion (talk) 23:22, 30 July 2023 (UTC)

That's a good point. I hadn't thought of it that way, but I find myself agreeing with Ceinturion (talk · contribs). Dondervogel 2 (talk) 07:38, 31 July 2023 (UTC)

It can be mentioned as being used as an alternative to μ in some situations - that is a prefix. -- DeFacto (talk). 07:40, 31 July 2023 (UTC)

I think the point is that mcg is an abbreviation of microgram. To claim that mc is a prefix would require a source stating that. Do you have one? Dondervogel 2 (talk) 08:52, 31 July 2023 (UTC)

If we were going to add something to the article, it would be nice to find a good source that indicates whether this only occurs in the US, or if it is done in many countries. Jc3s5h (talk) 10:11, 31 July 2023 (UTC)

Looks like it might be used by the UK NHS. Dondervogel 2 (talk) 10:31, 31 July 2023 (UTC)

Someone unfortunately added mcg to the article today. An additional problem is he did it in such a way that he claims without a source that the reason for using mcg was that typewriters are lacking a "µ" key. However, sources [1] state that the reason was that in handwriting, the symbol “µ” can look like an “m.” Ceinturion (talk) 12:37, 31 July 2023 (UTC)

Indian currencies

Should definitely add the Indian use of lakh (100,000) and crore (see Indian numbering system 2A00:23C8:B903:2601:ED15:A9EE:FA49:31F0 (talk) 07:22, 6 September 2023 (UTC)

I added Lakh to 'See also'. Not sure more is merited. Dondervogel 2 (talk) 09:48, 6 September 2023 (UTC)

Ambiguous raising-to-a-power

I think this is either perfectly ambiguous and/or wrong: "1 km² denotes 1 km × 1 km = 10⁶ m², not 10³ m²"; I think it should be written more like "3 km² denotes 3 (km × km) = 3 × 10⁶ m², not 3 × 10³ m²" (and also not 9 of anything). An an example of "1×1" is ambiguous, and if you change the 1 to something else, say 3, I think you'll agree that it is erroneous to claim that 3 km² should be equal to 3 km × 3 km which would be 9×10⁶ m². I would request that someone more expert or confident than me update this example to at least be less ambiguous if not more correct. We are simply trying to convey that "prefixing" binds more tightly than exponentiation (which of course binds more tightly than multiplication). — Preceding unsigned comment added by 198.135.146.241 (talk) 19:16, 16 October 2023 (UTC)