I found an Apple speech-to-text bug!

[james_s]

Are you saying that "10 metres square" and "10 square metres" are the same thing?

They mean the same thing to me. It would have never occurred to me that somebody would interpret them differently. If I wanted to say that something was 10 meters by 10 meters I'd have said it's "10 meters on a side."

[ebastler]

As a slight aside, in high school, my physics teacher made a very good point that has stuck with me. With SI, you shouldn't say "10 volts", "10 ohms" etc. It should be "10 volt", "10 ohm". Plurals are language-specific. Interestingly, where I live, some people speak that way anyway ("fifty cent" )

Never thought about this. German actually does not even have a plural form for most units, including the length and weight units which are used everyday outside of a scientific context: meter, gram, kilogram etc..

Units of time are an exception, strangely. All of them (seconds, minutes, hours...) come with a plural form, and it would sound really awkward in German (as in English) to say: "It took me only 10 second to do this."

[tooki]

The SI apparently states unambiguously that 10 meters squared = 10 m². However, nearly every reply (including ones by mathematicians) say that 2 meters squared = 4 m². The SI does not, however, address what “10 meters square” is supposed to mean.

And nor should SI address what it means. SI is a system of units, not calculations or algebra. SI is concerned with <number><unit>. So, the number is utterly divorced from everything else. 10 is 10. 10 what? Whatever the units specified are.

It is correct to say that the square of "ten meters" is "100 meters squared" since it is (10 m) x (10 m) = 100 x (m x m) = 100 m².

As a slight aside, in high school, my physics teacher made a very good point that has stuck with me. With SI, you shouldn't say "10 volts", "10 ohms" etc. It should be "10 volt", "10 ohm". Plurals are language-specific. Interestingly, where I live, some people speak that way anyway ("fifty cent" )

Done correctly, SI can get rather confusing, though. For example, the thing I measure has units of m²s^-1V^-1. What it represents is the velocity of an object (m.s^-1) moving in an electric field (V.m^-1), so "velocity per unit electric field".

The SI absolutely does specify the terminology, too.

As you said, they expressly say that the units follow the rules for nouns in the language in use. So I’m not sure how you interpret that to mean that saying “10 volts” is wrong in English. In English, if it’s a noun, then it gets pluralized. If it’s an adjectival noun (i.e. a noun being used to modify another noun) then it’s generally singular. Hence “what’s the voltage of that battery? - 3 volts” but “it’s a 3 volt battery”.

[JohnnyMalaria]

The SI apparently states unambiguously that 10 meters squared = 10 m². However, nearly every reply (including ones by mathematicians) say that 2 meters squared = 4 m². The SI does not, however, address what “10 meters square” is supposed to mean.

And nor should SI address what it means. SI is a system of units, not calculations or algebra. SI is concerned with <number><unit>. So, the number is utterly divorced from everything else. 10 is 10. 10 what? Whatever the units specified are.

It is correct to say that the square of "ten meters" is "100 meters squared" since it is (10 m) x (10 m) = 100 x (m x m) = 100 m².

As a slight aside, in high school, my physics teacher made a very good point that has stuck with me. With SI, you shouldn't say "10 volts", "10 ohms" etc. It should be "10 volt", "10 ohm". Plurals are language-specific. Interestingly, where I live, some people speak that way anyway ("fifty cent" )

Done correctly, SI can get rather confusing, though. For example, the thing I measure has units of m²s^-1V^-1. What it represents is the velocity of an object (m.s^-1) moving in an electric field (V.m^-1), so "velocity per unit electric field".

The SI absolutely does specify the terminology, too.

As you said, they expressly say that the units follow the rules for nouns in the language in use. So I’m not sure how you interpret that to mean that saying “10 volts” is wrong in English. In English, if it’s a noun, then it gets pluralized. If it’s an adjectival noun (i.e. a noun being used to modify another noun) then it’s generally singular. Hence “what’s the voltage of that battery? - 3 volts” but “it’s a 3 volt battery”.

My point (or, rather, my teacher's point) is that to avoid confusion across languages, don't use plural forms of unit names.

Sadly, having worked in the pharmaceutical industry, I have had to defile the SI purist in me, even going as far as using L for liter instead of l. Yes, yes, it avoids confusion - but, as another teacher pointed out - there was no Monsieur Litre. And there's mcg for microgram. Ugh.

[Nominal Animal]

using L for liter instead of l

Perfectly reasonable, unless one can safely use ell, ℓ, instead.  (Unicode U+2113, or code point 8467, &#8467; in HTML, \ell in MathJax etc.)

Similarly for mcg, if µg is not safe to use. (µ being Unicode U+00B5, or code point 181, &#181; in HTML, \mu in MathJax etc.  On my keyboard layout, AltGr+m.)

[james_s]

My point (or, rather, my teacher's point) is that to avoid confusion across languages, don't use plural forms of unit names.

Sadly, having worked in the pharmaceutical industry, I have had to defile the SI purist in me, even going as far as using L for liter instead of l. Yes, yes, it avoids confusion - but, as another teacher pointed out - there was no Monsieur Litre. And there's mcg for microgram. Ugh.

I'm not going to mangle my language in order to ostensibly ease translation into some other language, it sounds weird and awkward to use singular unit names and frankly it seems like a total non-issue and hardly the most tricky part of translating something to another language. If the translator knows and understand the rules of English then they will be able to translate the wording into whatever other language correctly.

Makes perfect sense to use L instead of l when there is a significant chance of ambiguity that could easily result in injury or death. Purist thinking is a form of idealism and is a problem in a world where nothing is absolutely ideal or pure. There are always cases where the benefits of breaking a rule outweigh the benefits of consistency.

[JohnnyMalaria]

My point (or, rather, my teacher's point) is that to avoid confusion across languages, don't use plural forms of unit names.

Sadly, having worked in the pharmaceutical industry, I have had to defile the SI purist in me, even going as far as using L for liter instead of l. Yes, yes, it avoids confusion - but, as another teacher pointed out - there was no Monsieur Litre. And there's mcg for microgram. Ugh.

I'm not going to mangle my language in order to ostensibly ease translation into some other language, it sounds weird and awkward to use singular unit names and frankly it seems like a total non-issue and hardly the most tricky part of translating something to another language. If the translator knows and understand the rules of English then they will be able to translate the wording into whatever other language correctly.

Makes perfect sense to use L instead of l when there is a significant chance of ambiguity that could easily result in injury or death. Purist thinking is a form of idealism and is a problem in a world where nothing is absolutely ideal or pure. There are always cases where the benefits of breaking a rule outweigh the benefits of consistency.

Why the wadded panties? I mention all this from a professional scientist's perspective for information purposes. I'm not suggesting 'Merican English speakers do the same. I certainly don't do it in casual conversation. However, there are journals that will reject your paper (or require editing) if you use L instead of l. There are some that insist on specific spellings for elements (e.g., sulfur/sulphur) or even one word in preference of another (aluminium instead of aluminum).

[Circlotron]

It is usual in Australian English to say something like “my car has a 50 litre fuel tank. I just put in 45 litres”. Singular and plural unit(s). And using a lower case l can be confusing because it can look similar to a 1 when hand written at least. And should the l be spaced away from the numerals? 50V fifty Volts looks okay but 50l fifty litres looks a bit sus.

[JohnnyMalaria]

And should the l be spaced away from the numerals?

Just FWIW, this is yet another source of disagreement between scientific disciplines and their journals. When I started out, spaces were mandatory between the number and the unit (e.g., 10 m.s^-1) but now I have to choose between with or without the space depending on the journal. It's no doubt just a matter of familiarity as to which looks "correct" - 10 m.s^-1 or 10m.s^-1 (or even 10 m/s and 10m/s - but the use of / instead of negative exponents is yet another source of contention).

I just go with the flow as dictated by the journal. Likewise, I use English grammar for UK journals and US English grammar for US journals.

[james_s]

Why the wadded panties? I mention all this from a professional scientist's perspective for information purposes. I'm not suggesting 'Merican English speakers do the same. I certainly don't do it in casual conversation. However, there are journals that will reject your paper (or require editing) if you use L instead of l. There are some that insist on specific spellings for elements (e.g., sulfur/sulphur) or even one word in preference of another (aluminium instead of aluminum).

The only wadded panties are the ones you read into what I said, I guess it's hard to convey tone in text. He's welcome to an opinion, I just happen to disagree and think it sounds awkward and I question the benefits. I'm sure there are journals out there that reach that extreme level of pedantry, certainly that seems to be more common among engineers and scientists than the general public. I'm not publishing anything in scientific journals though so it isn't something I've had to deal with.

[penfold]

I believe a more accurate subject line would have been "I found a bug in the English language!"

[tooki]

My point (or, rather, my teacher's point) is that to avoid confusion across languages, don't use plural forms of unit names.

Well that’s just stupid, and I say that as a multilingual person who did professional technical translation for a few years. For the supposed added clarity for non-native readers, you mangle it in the language it’s in?! That makes no sense. And the entire premise is dubious: Note that the unit names are localized, the symbols are not, and the symbols are not pluralized.

 

I'm not going to mangle my language in order to ostensibly ease translation into some other language, it sounds weird and awkward to use singular unit names and frankly it seems like a total non-issue and hardly the most tricky part of translating something to another language. If the translator knows and understand the rules of English then they will be able to translate the wording into whatever other language correctly.

Makes perfect sense to use L instead of l when there is a significant chance of ambiguity that could easily result in injury or death. Purist thinking is a form of idealism and is a problem in a world where nothing is absolutely ideal or pure. There are always cases where the benefits of breaking a rule outweigh the benefits of consistency.

Exactly.

[tooki]

It is usual in Australian English to say something like “my car has a 50 litre fuel tank. I just put in 45 litres”. Singular and plural unit(s).

That’s how it works in all dialects of English, as I explained above. It has to do with whether the unit is serving as a noun or a modifier.

Just FWIW, this is yet another source of disagreement between scientific disciplines and their journals. When I started out, spaces were mandatory between the number and the unit (e.g., 10 m.s^-1) but now I have to choose between with or without the space depending on the journal. It's no doubt just a matter of familiarity as to which looks "correct" - 10 m.s^-1 or 10m.s^-1 (or even 10 m/s and 10m/s - but the use of / instead of negative exponents is yet another source of contention).

I just go with the flow as dictated by the journal. Likewise, I use English grammar for UK journals and US English grammar for US journals.

The company where I as the translator is a software company that makes reference management software (i.e. a database that helps format proper bibliographies, footnotes, and inline citations; EndNote is their biggest competitor). And one thing I learned there is the absolute insanity that are citation styles. Some are straightforward, others are just crazy, with exceptions to exceptions to exceptions to exceptions. Nearly every publisher (and many individual journals) has its own house style. That software now has a library of over 10000 styles...

The issue of slashes in units is addressed by SI, at least as far as prohibiting multiple slashes.

The only wadded panties are the ones you read into what I said, I guess it's hard to convey tone in text. He's welcome to an opinion, I just happen to disagree and think it sounds awkward and I question the benefits. I'm sure there are journals out there that reach that extreme level of pedantry, certainly that seems to be more common among engineers and scientists than the general public. I'm not publishing anything in scientific journals though so it isn't something I've had to deal with.

Well, in his defense, I can attest to the journals being extremely pedantic...

[TimFox]

My point (or, rather, my teacher's point) is that to avoid confusion across languages, don't use plural forms of unit names.

Sadly, having worked in the pharmaceutical industry, I have had to defile the SI purist in me, even going as far as using L for liter instead of l. Yes, yes, it avoids confusion - but, as another teacher pointed out - there was no Monsieur Litre. And there's mcg for microgram. Ugh.

I'm not going to mangle my language in order to ostensibly ease translation into some other language, it sounds weird and awkward to use singular unit names and frankly it seems like a total non-issue and hardly the most tricky part of translating something to another language. If the translator knows and understand the rules of English then they will be able to translate the wording into whatever other language correctly.

Makes perfect sense to use L instead of l when there is a significant chance of ambiguity that could easily result in injury or death. Purist thinking is a form of idealism and is a problem in a world where nothing is absolutely ideal or pure. There are always cases where the benefits of breaking a rule outweigh the benefits of consistency.

Why the wadded panties? I mention all this from a professional scientist's perspective for information purposes. I'm not suggesting 'Merican English speakers do the same. I certainly don't do it in casual conversation. However, there are journals that will reject your paper (or require editing) if you use L instead of l. There are some that insist on specific spellings for elements (e.g., sulfur/sulphur) or even one word in preference of another (aluminium instead of aluminum).

The NIST guides to the SI list the liter as a non-SI unit of volume (as opposed to the m³) “that is accepted for use with the SI”,  and give the abbreviation as a majuscule L.

[Cerebus]

The NIST guides to the SI list the liter as a non-SI unit of volume (as opposed to the m³) “that is accepted for use with the SI”,  and give the abbreviation as a majuscule L.

Well NIST (from the land of pounds, feet at al.) is not the definitive source on the SI. The definitive source on the SI is the BIPM, which says in the currently definitive 9th edition of the SI Brochure:

5.2 Symboles des unités

Les symboles des unités sont imprimés en caractères droits, quelle que soit la police employée dans le texte où ils figurent. En général les symboles des unités sont écrits en minuscules mais, si le nom de l’unité dérive d’un nom propre, la première lettre du symbole est en majuscule.

Le symbole du litre constitue une exception à cette règle. La CGPM à sa 16e réunion (1979, Résolution 6) a approuvé l’utilisation de la lettre L en majuscule ou l en minuscule comme symbole du litre afin d’éviter la confusion entre le chiffre 1 (un) et la lettre l.

So, both upper and lower case are acceptable notation for 'litre'. One might choose to read from the above a suggestion that someone in the 1979 meeting felt that the lower case form is the 'proper' notation and that upper case is only being grudgingly permitted for purposes of disambiguation.

Moreover the 12th CGPM of 1960 "declares that the word “litre” may be employed as a special name for the cubic decimetre" and that it was not to be taken to be the former definition of the litre which was the volume of 1 kg of pure water at STP. It was recommended at the 1961 CIPM meeting that "The Comité International des Poids et Mesures recommends that the results of accurate measurements of volume be expressed in units of the International System and not in litres." - that recommendation still stands.

So one can see that it seems the humble litre is a bit frowned on in certain circles of the BIPM.

The English text of the above for those who prefer:

5.2 Unit symbols

Unit symbols are printed in upright type regardless of the type used in the surrounding text. They are printed in lower-case letters unless they are derived from a proper name, in which case the first letter is a capital letter.

An exception, adopted by the 16th CGPM (1979, Resolution 6), is that either capital L or lower-case l is allowed for the litre, in order to avoid possible confusion between the numeral 1 (one) and the lower-case letter l (el).

[TimFox]

As a patriotic American, I follow NIST, which does not contradict the BIPM.   My recent prescriptions for 5 mL of liquid, are easy to read because of this.
It is interesting that the BIPM explicitly changes to a strict volume definition of the liter and disavows the previous one related to water density, since there was a small discrepancy after switching from the previous definition of the kg to the artifact kg.

[Neganur]

To me, 10 square metres is as it sounds but 10 metres square is 10x10 metres i.e. 100 square metres.

I see it like this, your 10x10 example would be metres squareD (as in (10m)^2), not square. Just "square" is too ambiguous (what are you squaring, the 10 or the unit or both?) and we probably cannot agree on anything in this case.

In English: 10 metres squared = 100 square metres
In German: 10 Meter im Quadrat = 100 Quadratmeter".

I do agree with Tooki's reasoning though in terms of "5 V^2 Hz^-1 is not squaring the 5".
However, there is no "square metre" equivalent word for "Volt to the power of two" would be my first reaction without having spent too much thought on it.


It's not easy to to express things in a precise manner.

[TimFox]

In the US, 55 years ago, I was taught that "10 meters square" was 10 m x 10 m= 100 m² = "100 square meters", but since that could be misinterpreted we should say "10 by 10 meters" (or similar) instead to avoid confusion.

[Bassman59]

As a little additional note.....

I find it rather telling when you see a real estate advertisement for a property which states the property is "10 square metres" when it is clearly apparent that the property is "10 squares" in size.

The real-estate business has a worse problem. They (at least here in the US) indicate the size of the property as "±10,000 ⏍."

Yes, that's right. They tell you the error in measurement, not the actual area, and they use a silly symbol instead of just saying "square feet."

[Cerebus]

As a patriotic American, I follow NIST, which does not contradict the BIPM.

This isn't the place for pointless flag-waving, especially when discussing the "Système international". The very name is a giveaway that the one thing it's not about is nationalism.

[TimFox]

Well NIST (from the land of pounds, feet at al.) is not the definitive source on the SI. The definitive source on the SI is the BIPM, which says in the currently definitive 9th edition of the SI Brochure:

I was reacting sarcastically to your comment.

[Cerebus]

Well NIST (from the land of pounds, feet at al.) is not the definitive source on the SI. The definitive source on the SI is the BIPM, which says in the currently definitive 9th edition of the SI Brochure:

I was reacting sarcastically to your comment.

Well, you need to get better at sarcasm then so it's obvious, and that still doesn't make NIST, fine institute that it nevertheless is, a suitable referent for definitive information on SI (If you've accurately reported what they say, that 'litre' should be represented only by a capital 'L', then they're wrong according to the actual authority for the SI.)

[TimFox]

NIST follows the US Government Printing Office standard of "liter", abbreviated "L".  That is one of two choices allowed by BIPM.  It works for me.  The liter is not a SI unit anyway, and the two miniscule choices (ℓ and l), although they follow the general rule for non-proper nouns, are easy to confuse.

[ebastler]

In the US, 55 years ago, I was taught that "10 meters square" was 10 m x 10 m= 100 m² = "100 square meters", but since that could be misinterpreted we should say "10 by 10 meters" (or similar) instead to avoid confusion.

"10 by 10 meters" equals 100 meters, hence is a length and not an area at all. 

[TimFox]

No.  In context, it is a description of a geometric square with dimensions of 10 m by 10 m.