Talk:International System of Units/Archive 2

"Basis"

In the section "Basis", I read..

"The prefixes are never chained, so a millionth of a kilogram is a milligram, and not a 'microkilogram'."

Reading that once, I went... wait.. what? milli- is a thousandth... why is the article talking about millionths of a kilogram being a milligram.. ? I immediately think to myself.. have I been wrong all along.. Is milli- a millionth? Couldnt be! I actually had to go reassure myself by looking at SI prefixes to figure out what that sentence was trying to say.. It's somewhat confusing to a casual obvserver who's half drunk.. milli- in conjunction with "millionth" is too odd. perhaps change it to something like... a meter is not a decimillimeter???..

--Kvuo 22:44, 3 Jun 2005 (UTC)

One point is that prefixes are not added to the word "kilogram" even though it is a "base unit", a term with a different meaning. Changing it to meters would miss the point entirely (a similar point could be made concerning the centimeter as a base unit in cgs systems, but there's no reason to make that point here). The broader point about not using double prefixes at all could be made by saying that it is no longer proper to call a picofarad a micromicrofarad, and there are other example where the no longer acceptable double prefixes were used in the past. Gene Nygaard 11:39, 4 Jun 2005 (UTC)

The Kogram

I propose the use Kogram as the name for the unit of mass. Kogram is a family name and the name of a village in India. This does away with the prefix kilo in the name. As ``Kogram is a family name, there is no risk of clashing into another meaning of the same term. Units derived from names by SI rule start with a capital. Thus we use Kg. Now we can, hurray!, use mKg, uKg, MKg, like mWb, uWb, MWb (Weber, unit of magnetic flux) or mPa, uPa and MPa (Pascal, unit of pressure) (here, u=micro). The only thing missing is to find some dead guy, who worked in physics and happens to have the family name ``Kogram, so we can name the Kogram in honor of him! --RitaBijlsma

---

The basic unit of mass isn't the kilogram, it's the gram. But that's not the point: this is an encyclopedia, not a standards committee. It's not in our purview to name, or rename, units of measurement, cities, novels, or anything else: our task as Wikipedians is to describe and explain what's out there. --Vicki Rosenzweig

It isn't the gram, it's the kilogram, but it should be the gram :-) Somebody majorly screwed up somewhere. But I agree, we shouldn't try to invent new names. Also, we should probably mention that the kilogram is still to this day defined by a cube of metal in Paris. --AxelBoldt

No, it is the kilogram for a good reason, see below. I wrote it while you wrote this ;-0

Yes, the cube is important. It is made of platinum-iridium and kept at the BIPM (Bureau international des poids et mesures)--RitaBijlsma

Oeps, the reason may not be clear: if you already have the kg in the derived units, you can not just take the gram as the unit to get prefixes consistent, because then the rest is inconsistent and you can not change all derived units to solve that.

The gram is too small to be practically usable. That is why the kilogram is used. I agree in a way with Rita, though, because for all purposes, we use the kilogram, but linguistically, we use the gram. Even so, putting these ideas into an encyclopedia article sounds like overkill, if you ask me. Sabejias

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Ok, I added SI, in the international system of units, the kilogram is the unit of mass, not the gram. See NIST special publication 330, or anywhere else. Because the kilogram is the unit of mass, derived SI units are defined in terms of the kilogram, for example the N = m * kg / s^2 Any derived SI unit is defined in terms of the basic units. So the gram is never used in derived units. This consistent choice allows for great convenience in calculations, especially in automated calculations. The decision that prefixes should be added to the gram instead of the kilogram reduces convenience considerably. And that should not be taken lightly. International definitions that lead to errorprone usage cause small losses of time and money all over the world and that adds up to considerable losses. Its not in my intention to blame the SI commitee. I think that they do a wonderful job that is benificial to all of the world. I just propose some solution for a historical problem.

About stating what is out there: That problem is out there and that frustration is out there, not only in me. Ridiculing my proposal by an unfounded association with renaming novels is no way of engaging in a discussion.

It is not correct to say that I try to do the work of a standard commitee here. A standard committee can not make proposals. They make rules. They can not politically afford to make proposals. No one screwed up with respect to the kilogram. For a system that is globally used to prevent miscommunications, every addition or improvement has to be backward compatible. The SI committee never had the freedom of just making a consistent system and then proudly give it to a waiting world. A large part of their achievements has been political: find out which rules have a large chance of being generally accepted. They have reacted and will react on current general usage. General usage means that many people do the same thing. But if someone wants to start using a new term for the kilogram, just for his own notes, not in published articles, but with the future in mind, then he needs knowlegde on what would generally be a good idea to use: what term would not be ambiguous? what abbreviation (G?, Kg?) can accompany it and is not already in use for some other unit, or ambiguous in another way? These are questions about what is already out there, it is encyclopedic information. I did some research, checked the ambiguity of other terms. They all were impossible. Then I, wauw, found this niche, the term Kogram. That is what I propose to tell in the article: given all that there is out there, there is a niche. Offer that encyclopidic information to anyone who asked himself, like me, if there is a niche left, a term that is save to use. I hope to find others, willing to check if I'm right, if Kogram would be safe and to find if there is guy we can name it after to make the whole idea complete. --RitaBijlsma

Please don't do that, Rita: this is an encylopedia, not a vehicle for personal original research, however well-intentioned. Please let us know when you have a substantial number of people using the Kogram, and we can then add it to the article. Until then, it does not belong here. The Anome 10:32 Feb 7, 2003 (UTC)

How about renaming the kilogram the "grave"? Jimp 5Oct05

"l" vs. "L" for litre

""l" is commonly used, but is deprecated for being too similar to "1"."

I was always led to believe that the lower-case "l" was the official way to write it, and that "L" was the US standard. Is this not true any more? I also added the comment about using "ℓ" - I find it quite regularly in Japanese text (it's in all Japanese fonts I know of too), and I occasionally find it here in Ireland too, for example most 2-litre milk bottles have a big "2ℓ" on the plastic. --Zilog Jones 23:36, 30 July 2005 (UTC)

Both l and L have been officially accepted for several years; the script el is not acceptable in modern rules. Yes, there are some remnants of its use, likely considerably less than we saw 30 or 40 years ago. We also see far too much use of the kilogram-force (including the metric horsepower (PS or CV) defined as 75 kgf·m/s) as well, even though the keepers of our standards have been telling us for 45 years to stop using them as well. The symbols for liters are discussed in more detail under litre and probably its talk page too. That's a good place to continue any discussion of this. Gene Nygaard 01:48, 31 July 2005 (UTC)

Perhaps, but this article is the one that contains the misstatement. "L" is not the "official" symbol for litre. "l" is the official symbol, and "L" is an officially accepted alternate. It's true that NIST recommends the use of the "L" alternate in preference to the standard "l", and for what it's worth, I agree with them, but neither their opinion nor mine changes the facts in The Brochure published by the BIPM. Nowhere have I seen any support for the allegation that "l" is actively deprecated by any reputable authority. How can the use of the official standard be deprecated? Anyone want to talk me out of fixing this? --Jeepien 06:03:20, 2005-08-05 (UTC)

Thus both are official. And of course use of an "official standard" can be deprecated; in fact, the CIPM and CGPM have wanted to trim it back to only one symbol for the liter, and in order for that to happen, there would have to be some groups out there pushing for one to be used in preference to the other. But in fact, the "official standard" is that the liter is unnecessary; it is not part of the International System of Units, merely something that is only tolerated as acceptable for use with the modern metric system (and even that wasn't true when the SI was adopted in 1960, before it was restored to the old definition of exactly one decimeter). What kind of "fixing" do you have in mind? Gene Nygaard 08:37, 5 August 2005 (UTC)

I had in mind fixing the false statement:

The one exception is the litre, whose offical abbreviation is "L". "l" is commonly used, but is deprecated for being too similar to "1" which has two official symbols, "l" and "L".

The present text is wrong because it implies that there is only one standard symbol, and because it implies that "l" is not a standard usage, but a "common" usage. There is already a link to litre for more info, and that's probably where the details should go, especially since this is the SI article, and the litre is merely tolerated by the SI. Personally, I agree that "L" should be the standard, but my POV doesn't belong in the article. --Jeepien

Done. – Smyth\^talk 10:09, 6 August 2005 (UTC)

Ireland

There's an edit fight over Ireland. Are they fully compliant, or partially compliant? --Jeepien 05:15:38, 2005-08-06 (UTC)

SI and ISO

Is there a relationship between SI and ISO? There are only two links to ISO at the bottom. Surely, there is more to say about the relationship between the two. DirkvdM 08:18, 13 August 2005 (UTC)

Like what? --Jeepien

Well, they're both concerned with standardisation of units of measurement. I don't know much else, except that ISO is often stricter than others and that it covers a much wider field. But surely there will be an overlap that deserves mentioning. Anyway, don't ask me, I'm asking you :) . DirkvdM 19:38, 13 August 2005 (UTC)

The first thing to remember is ISO is an organisation whereas the SI is a standard. I'm not an expect but from this article and general knowledge I believe the BIPM defines and makes recommendations about the SI. The ISO takes and publishes these definitions and recommendations in an international standard which you can purchase. 60.234.141.76 10:47, 14 August 2005 (UTC)

That makes it sound like ISO is just a publisher. But I've heard on various occasions that ISO is more strict than the other organisations whose standards it publishes (like with the HTML-standard, but also with SI standards), indicating that they do more than just publish them. DirkvdM 17:57, 14 August 2005 (UTC)

Comma versus dot

SI used only a comma as the separator for decimal fractions until 1997. The number "twenty four and fifty one hundredths" would be written as "24,51". In 1997 the CIPM decided that the British full stop (the "dot on the line", or period) would be the decimal separator in text whose main language is English ("24.51"); the comma remains the decimal separator in all other languages.

Is the "all other languages" part actually true? In practice, many other languages follow the English usage of a dot for the decimal separator (Japanese is one that comes to mind). Are they doing so in a manner officially contrary to the Metric Police, or are there additional exceptions for other languages? --Delirium 06:30, Jun 10, 2004 (UTC)

I am sure that at least in Brazil (I have seen many europeans I know using this, but can't actually tell if it is the rule in their countries of origin), the rule is dot for 3-digit separation and comma for decimal. For example the american 345,213.50 is written 345.213,50. --Poli 18:13, 9 Mar 2005 (UTC)

If moved this to the front since it'll probably get lost otherwise. I've changed the article since the original statement which was "In practice, the full stop is used in English, and the comma in all other languages." is most definitely incorrect.

I know as a fact the full stop is used in Malay, and I'm pretty sure it's used in Chinese, Japanese, Korean, and most/all Indian languages as well (Tamil, Hindi etc). Possibly Arabic too. I'm suspect it's not in all other European languages either since Gaelic is a European language but I suspect they use the full stop as well. Personally, I suspect this statement is misleading since I suspect it's more to do with your country and culture then your language. For example, many non-UK & Ireland Europeans (French, Germans etc) would use the comma even when writing in English, especially if they are writing to some other non-UK European.

The full stop is probably used by cultures and in countries influenced mostly by the British or American tradiation whereas the the comma is probably used by those influence mostly by other most other Europeans. Does anyone know what French Canadians use? According to XP x64 it's the comma but this could be wrong. According to XP x64, the full stop is used by French-Swiss in any case. As an example when XP x64 is definitely wrong, it claims the comma is used for Malay (Malaysia) which as I've said, is not the case, unless you're going to tell me the 14 or so years I spent in schools in using the full stop and reading it in text books, papers, exams etc is somehow wrong. 60.234.141.76 10:40, 14 August 2005 (UTC)

Canadian French uses a decimal comma; Canadian English uses a decimal point. Indefatigable 16:36, 14 August 2005 (UTC)

In connection with my posting hereabove, I believe that the ISO standard is to use a comma as a decimal separator (and possibly the dot as a thousands-separator, although that is probably optional). It also seems to make more sense to use a comma as the decimal separator since in reading it is more noticeable and in writing a pen-written dot can even not come out at all. And the decimal separator is more important than the thousands-separator. It is actually quite essential, whereas the thousands-separator is just a reading-aid that can even be left out. Not that this should go in the article, I just wanted to point it out :) . DirkvdM 18:01, 14 August 2005 (UTC)

If you can document it, it should go in this article, or ISO. I would hope they would not be so frivolous; this is about as silly as an ISO standard language. The comma separator, however, goes back at least to the seventeenth century, IIRC; so it was not produced by metric. Septentrionalis 22:31, 14 August 2005 (UTC)

Silly? What does 12,345 mean? Confusion with stuff like this can crash a marslander. Well, actually, that was a mixup between metres and feet, I believe, but I just mean to say that standardisation with this sort of thing is quite a bit more important than, say, whether one writes standardisation or standardization. DirkvdM 08:15, 15 August 2005 (UTC)

Way back in 1975, the Canadian Guide d'usage du système métrique wrote that the decimal marker was, according to ISO 31/0, the comma but that in English documents, the comma or the period can be used. Urhixidur 17:14, 2005 August 15 (UTC)

There is only one acceptable thousands separator in the SI, and that is the space. So, if there is either a comma or a dot, one should be able to assume that it is a decimal separator. --Jeepien 03:10:23, 2005-08-16 (UTC)

Sounds good in theory, and I have seen it used frequently enough. But the problem (as with any standard) is that people will have to know this is a standard (or rather the standard) and I doubt if many do. The nice thing about this solution, though, is that it doesn't 'offend' either group.

Which brings me to an interresting, more general question. In how far should Wikipedia educate by example? Should we agree to use one standard throughout Wikipedia? Or is there already a Wikirule on this? I mean specifically this and more in general? Like, say, extending the standard of putting a unit after the value to money (so "1 €" in stead of "€ 1")? Though I'm deviating now :) . DirkvdM 09:19, 16 August 2005 (UTC)

Bread in USSR

"For example, bread is sold in one-half, one or two kilogram sizes in many countries, but you buy them by multiples of one hundred grams in the former USSR".

Having lived in the former USSR for 20 years, I find this statement inaccurate, at best. You can't walk into a store in the former USSR and ask for X*100 grams of bread. Bread is simply not sold by weight. You can only buy multiples of half-loaves. Besides, there is no "standard loaf of bread", one loaf can weigh anywhere from 400 to 850 grams.

There is, however, a standard unit of measurement called "100 grams." When used without specifying the subject of measurement ( e.g. "would you like 100 grams?" ), it invariably refers to vodka. --Itinerant1 06:50, 12 September 2005 (UTC)

Constants in CGS

I removed the prickly section about "fabricated" constants. The sentence was awkward and run-on to begin with. The permittivity of the vacuum can be measured and has been verified. It fulfills the scientific definition of the word "constant". As for the alleged problems with the CGS system, it would be preferable to have a comparison section or related stub article, rather than a brief, unsubstantiated dismissal. Hopefully someone with expertise can do the upgrade in a neutral POV and with encyclopedic tone.

The sentence may have been awkward; the point is valid. The electrical constant (permittivity of a vacuum) and magnetic constant (permeability of free space) are defined, not measured, in the context of SI, and different in various cgs and other systems (both equal one exactly in Gaussian cgs units). Gene Nygaard 14:12, 27 September 2005 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:International System of Units/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

The symbol for litre is lower case l, not L. This article and several others use incorrecly "mL", "mmol/L" etc. This is often seen with mlllisecond also, which should be ms, not mS. Wilbert (talk) 10:13, 14 November 2011 (UTC) This is not true. The CIPM has allowed two symbols for litre: both lower case and upper case L. The latter was added because many fonts do not distinguish between lower case l and the number 1. Since the lower case is the more used version, I think it is good, because of style consistency, only to use this one on Wikipedia. This is the only place where two symbols are allowed and mS is obviously wrong if it is supposed to mean millisecond, just like the often seen Kg for kilogram is wrong.

Last edited at 10:13, 14 November 2011 (UTC). Substituted at 14:36, 14 April 2016 (UTC)

About "Britishizing" International System of Units

Moved here from my talkpage. -- DeFacto (talk). 07:06, 15 May 2020 (UTC)

The Wiktionary says that amid and among are preferred to amidst and amongst on both sides of the Atlantic; and -isation is regarded as British but not used by "Oxford" English; so considering that in general a good reason is needed to change the "dialect" of a Wikipedia page, I have some doubts about the wellfoundedness of your latest edit of the International System of Units page. I'm not going to revert it since it would be doing the very kind of change to which I'm raising an objection here; but I'd like an explanation. — Tonymec (talk) 07:00, 15 May 2020 (UTC)

@Tonymec: according to the banner at the top of this page, this article is written in British English (and not British Oxford English), and all other instances of 'is'/'iz' words were already spelt with the 'is' anyway (idealise, standardise, recognise, etc.). For that reason I fixed the spellings of the few anomalies per MOS:RETAIN. -- DeFacto (talk). 07:14, 15 May 2020 (UTC)

ah, the banner is on the Talk page and I looked for something at the top of the Article page. Sorry for the noise. — Tonymec (talk) 07:18, 15 May 2020 (UTC)