Talk:Metric prefix

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Proposed Extensions[edit]

I altered the OP's post stating, "Of these only the litre is still in ubiquous(sic) use." In my experience, what the OP defines as an "are" is known as a(n) "hectare", that being an area equal to 56,000m2[1] (100mx100m). This term is used VERY widely as a pseudo-SI alternative to "acre" when talking about land and must, I would think, qualify as being in "ubiquitous" use? Also according to Google[2], an "are" is 1/100th of a hectare, or 10m2. As a result of this supporting evidence, I also altered the relevant parts of the post to reflect these values. 17:49, 21 March 2006 (UTC)Reply[reply]

I'm not quite sure of where your figure of 56000 m2 comes from. It doesn't seem to have influenced anything in the article, so there's no harm done. Obviously 100 m x 100 m is 10000 m2 = 1 hectare. Yes, an "are" is an area of 100 m2, and is used in Spain for measuring the floor space of buildings.--King Hildebrand 16:50, 2 August 2006 (UTC)Reply[reply]
That arithmetic is insane. 100 x 100 = 10,000, and 1 hectare is "equal to 10,000 square metres (104 m2)". --Thnidu (talk) 03:48, 8 February 2015 (UTC)Reply[reply]
Four New extensions have been approved in the 3rd Resolution of the 27th CGPM of BIMP, and should be updated on the SI infoBox.
These are:
10^27 - Ronna(R)
10^-27 - Ronto (r)
10^30 - Quetta (Q)
10^-30 - Quecto (q)
Ryzvonusef (talk) 16:01, 18 November 2022 (UTC)Reply[reply]


Do doctors in American medical soap operas always say "cc" (short for "cubic centimetre") to mean "millilitre" because they don't want the audience to know they're using a metric unit? At least here in Finland, "millilitre" is a much more widely known unit than "cubic centimetre", even though they're the same thing. JIP | Talk 17:17, 1 May 2005 (UTC)Reply[reply]

No, all doctors in America use cc. Cburnett 17:25, May 1, 2005 (UTC)
Why do they call it cc instead of millilitres, then? JIP | Talk 18:52, 1 May 2005 (UTC)Reply[reply]
I wouldn't tak that as an established fact based on one person's comments. For example, what specific context do you have in mind? Liquid drugs are usually labeled in milliliters, and so prescribed. What's used for capacity of syringes? For cranial capacity? The more prevalant usage can be different in different contexts.
You are probably just a kid who doesn't remember the days when we had to learn that milliliters and cubic centimeters are different units. Some of the usage habits today go back to those days when a distinction was sometimes made for clarity, even though very few measurements were ever precise enough to tell he difference. That's just one of the factors that come into play--but fooling the audience into thinking they are not using a metric units is one of the least plausible factors. Your theory doesn't hold any water. Americans know that it is a metric unit, whether it is "cc" or "cm³" or "mL". Gene Nygaard 19:23, 1 May 2005 (UTC)Reply[reply]
Actually, I've even seen liquid drugs measured in miligrams. In particular, morphine. Measuring liquids in cc's and solids in mg's are probably the most prevalent. I've *never* had a prescription filled in grains or ounces. :) But whatever is used and why, it has little to do with "fooling the audience". Cburnett 22:46, May 1, 2005 (UTC)
Really? I'm sure it was expressed in milligrams per mL if you check again. —Preceding unsigned comment added by (talk) 04:15, 16 May 2009 (UTC)Reply[reply]
If close to 30 years is "just a kid" to you, then I agree. But no, I don't remember ever learning that cubic centimetres and millilitres are any different. JIP | Talk 04:27, 2 May 2005 (UTC)Reply[reply]
From 1901 until 1964, 1 ml was approximately 1.000028 cm³. The liter was then defined as the volume of one kilogram of water at its maximum density, rather than as a cubic decimeter.Gene Nygaard 04:40, 2 May 2005 (UTC)Reply[reply]
Figures, seeing as I wasn't born in 1964. My parents hadn't even met each other then. The bit about fooling the audience was pure speculation on my part. JIP | Talk 14:48, 3 May 2005 (UTC)Reply[reply]

An old man such as myself remembers that many of our American textbooks of the late 1940 to pre-1970 era distinguished them as: cc = volume, ml = capacity (the latter being contingent on positive, neutral or negative meniscus formation of liquids). I hope this is some help; Dr.R.E.Petrere

Giga pronounciation[edit]

[ˈgɪgə] and [ˈdʒɪgə]. The former is more common than the latter. How do you know this?Seforadev 03:55, 20 June 2006 (UTC)Reply[reply]

Personal experience lends credence to the opinion in the article. I have been moving in scientific circles for forty or more years, and have very rarely heard the soft form, [ˈdʒɪgə], used. --King Hildebrand 13:44, 2 August 2006 (UTC)Reply[reply]
I'm not a scientist, but I say 'gigabyte' with a hard G, and I have only ever heard it that way. The only time I've ever heard the soft one is in "1.21 gigawatts." (talk) 15:00, 1 July 2014 (UTC)Reply[reply]
What said. Is there a reliable citation for the soft g pronunciation anywhere outside the BttF franchise? Even the filmmakers admitted that it was a mistake. — Preceding unsigned comment added by (talk) 10:54, 19 February 2020 (UTC)Reply[reply]
See Giga-#Pronunciation.--Srleffler (talk) 19:28, 20 February 2020 (UTC)Reply[reply]
Ugh, a holy war. So the short answer is "no" then. I think I will back slowly away from this one. Thanks for the pointer. (talk) 01:43, 23 March 2020 (UTC)Reply[reply]

Different people talk in different ways with different accents. There is therefore no standard proununciation. I have removed the relevant section. Andrew🐉(talk) 10:04, 25 November 2022 (UTC)Reply[reply]

Pronunciation citation[edit]

This sentence doesn't have anything even remotely official backing it up: "When an SI prefix is affixed to a root word, the prefix carries the stress, while the root drops its stress but retains a full vowel in the syllable that is stressed when the root word stands alone."

So, who says this? If it's just a common convention, then why must there be any sort of consistency. One gets the idea that someone just made this up. 08:28, 16 November 2013 (UTC) — Preceding unsigned comment added by (talk)

I have removed the relevant section as controversial and uncited. Andrew🐉(talk) 10:04, 25 November 2022 (UTC)Reply[reply]

§ Pronunciation[edit]

The pronunciation section is specific to English:

  • Metric prefix#Pronunciation: The prefix giga is usually pronounced /ˈɡɪɡə/ but sometimes /ˈdʒɪɡə/.
    (That is, usually with the first g "hard", as in game, but sometimes "soft", as in giant.)
  • French: /ʒi.ɡa/
    (Only soft as in géometrie, never hard as in gant.)
  • German: [giga]
    (Hard. German doesn't have a "soft g".)

... and so on.

But nowhere does it say so. Since we're defining an international set of prefixes and everything above this section applies worldwide, we really ought to make it clear that this section applies only to English. And so I'm renaming it "English pronunciation", keeping the old one-word name as an anchor so as not to break any links to it.

To discuss this, please {{Ping}} me. --Thnidu (talk) 04:24, 8 February 2015 (UTC)Reply[reply]

@Kbrose: What's your objection, please, to including the three-word phrase "in English as" in a section that discusses prefixes that are used in many different languages, are spelled the same in most or all of them that use the Latin alphabet, but are pronounced in many different ways? Yes, of course this is the English Wikipedia, but few articles deal with such a wide range of cross-linguistic homographous heterophony.
To discuss this, please {{Ping}} me. --Thnidu (talk) 01:12, 15 August 2016 (UTC)Reply[reply]
@Kbrose: Eight days, no answer. Reverting. --Thnidu (talk) 21:20, 23 August 2016 (UTC)Reply[reply]

As pronuciation is variable, controversial and uncited, I have removed the relvant section.

Ambiguity between prefixes and units (m, T)[edit]

I haven’t seen it mentioned here (or I missed it) but it seems to me that the symbols m and T can be ambiguous. mN could be 0.001 Newtons or 1 metre times Newton. Even if you introduce a rule that metres always go to the right Tm is ambiguous between 10^12 metres and 1 Tesla times metre.

Are there any rules on how to handle these? Are there more cases like this?

--2003:F0:8700:8400:249A:71C6:9A5A:B340 (talk) 11:19, 19 November 2022 (UTC)Reply[reply]

There is no ambiguity. The symbol mN always represents millinewton (and Tm always represents terametre). A product would be indicated by a space (m N) or a mid-dot (m·N). Dondervogel 2 (talk) 12:01, 19 November 2022 (UTC)Reply[reply]
Thanks for the reply. You are right, and while I’ve seen a lot of usages of Nm for newton-metre, they are technically not correct. --2003:F0:8700:8400:2CC3:8735:E2C1:3718 (talk) 12:55, 21 November 2022 (UTC)Reply[reply]
I've added a bit more on typography to address this. There was nothing to alert the reader about this typographic consideration for prefixes here, and it seems very close to the topic. —Quondum 13:12, 21 November 2022 (UTC)Reply[reply]


Naughty pixies find all zebras yodelling really quietly (talk) 07:55, 23 November 2022 (UTC)Reply[reply]

Many giant turtles plod; elegant zebras yodel really quietly — Preceding unsigned comment added by (talk) 20:13, 1 February 2023 (UTC)Reply[reply]

History of SI prefixes: nano-, pico-, giga-, tera-[edit]

Picofarad (with the symbol μμF) occurs in the "British Standard Glossary Of Terms Used In Electrical Engineering", 1926, p. 26: [3].

Nano-, giga-, tera- occur in 1932: see [4], page 252. Burzuchius (talk) 18:30, 3 December 2022 (UTC)Reply[reply]

Nice find! Double sharp (talk) 06:30, 10 December 2022 (UTC)Reply[reply]

Create a new article for ronna[edit]

I propose creating a new article for the new prefix ronna. WalkingRadiance (talk) 19:39, 6 December 2022 (UTC)Reply[reply]

I don't think that this would be productive. Amongst other things, WP is not a dictionary, nor is it a news outlet. Besides, there is almost nothing to say about it that does not apply to all the metric prefixes. —Quondum 21:34, 6 December 2022 (UTC)Reply[reply]
Where did my article on ronna go? WalkingRadiance (talk) 02:14, 7 December 2022 (UTC)Reply[reply]
Is my article still at a permanent link somewhere? I need to reference it even if it was deleted unless it was permanently deleted by an administrator. WalkingRadiance (talk) 02:16, 7 December 2022 (UTC)Reply[reply]
The history can be found under the "View history" tab at (the redirect) Ronna-, which takes you to (the history of) Ronna-. —Quondum 03:10, 7 December 2022 (UTC)Reply[reply]

References with issues[edit]

Both the Nature and the Guardian references are have issues.

  • The Nature article says: "an electron’s mass is about one quectogram", whereas it is about one rontogram.
  • The Guardian article is less complete, and includes a crackpot statement: "a single bit of data stored on a mobile phone adds about 10 quectograms to its mass".

Any better references would be welcome. In the interim, does anyone object to removing these? —Quondum 13:45, 14 December 2022 (UTC)Reply[reply]

Striking one above that was kindly removed. —Quondum 14:13, 14 December 2022 (UTC)Reply[reply]

Why “ronna” and “quetta”?[edit]

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)Reply[reply]

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)Reply[reply]