Paul:
Cannot agree with you more. As you wrote about the experiences in your
practice, calling unit sizes by different names is DANGEROUS. There are so
many "tons" that using Mg should be the prime safety concern.
Beside, citizens of every country understand (are taught) that using only
one language of measurement (SI) and one unit for ......... is good for the
world ("used with SI" - what a way to destroy the beauty of SI).
Concerning the useless are, it was spelled "ar" for generations. I guess,
the English like the letter e. I feel sorry for it as hardly ever anyone
pronounces it. Ignored like the "e".
I noticed your Middland story and was disappointed by your not using SI as
the wind people mostly use the SI m/s. !4 m/s happens also to be the
favorite wind speed for wind mills.
Stan Jakuba
On Fri, Apr 6, 2012 at 2:47 PM, Kilopascal <[email protected]> wrote:
> **
> I agree with you about the ton/tonne, but for now we are stuck with it due
> to its universality. At least the tonne is equal to the megagram and can
> be thought of as such. The mental conversion is very simple.
>
> The hectare is actually a perfect unit for area as it is equal to exactly
> one square hectometre. However, the are (100 m^2) from which it is
> based is incoherent with SI as it stands. The are should be equal to 1
> m^2. When dealing with areas, the prefixes should not be understood as
> being factors of 10, but of factors of 100, such that if 1 are (symbol: a)
> were assigned a value of 1 m^2, the dekare would be 1 square dekametre, the
> hectare would remain as it is, being one square hectometre, the
> kilare would be 1 square kilometre.
>
> Going the other way, the deciare would be 1 square decimetre, the centiare
> would be 1 square centimetre, the milliare would be 1 square millimetre,
> etc.
>
> If the stere were reintroduced for volume, then one stere would equal
> 1 cubic metre as it originally was, the dekastere would be 1 cubic
> dekametre, the hectostere would be 1 cubic hectometre, the kilostere would
> be 1 cubic kilometre.
>
> Going the other way, a cubic decimetre would be a decistere (this would
> replace the litre as the litre is not coherent in SI), a cubic centimetre
> would be a centistere, a cubic millimetre would be a millistere.
>
> Because areas and volumes create a factor of 100 and 1000 between each
> prefix, the prefixes centi, deci, deka and hecto become practical and
> useful. When the prefixes above kilo and below milli are factored in, the
> gap becomes huge, but such areas and volumes larger or smaller than kilo
> and milli would rarely if ever be encountered, only by scientists.
>
> I don't think the are is presently ever used in real life, so there should
> be no problem redefining it as 1 m^2. Also, it presently is not a part of
> SI so it shouldn't matter if its old definition was 100 m^2, but its SI
> definition would be 1 m^2. SI doesn't have to recognize the
> old definitions of units outside of SI if it chooses to adopt these units
> into SI.
>
> If the words "are" and "stere" appear clumsy, then I'm sure some new words
> can be created that fit the prefixes more and flow when spoken. One
> advantage to using are and stere to mean 1 m^2 and 1 m^3 is that there
> symbols will not be based on the square or cubed symbol and the difficulty
> in displaying the square and cube symbol ends.
>
> One other idea would be to spell are as simply ar and not confuse it with
> the verb are in english.
>
> What do you think of this idea?
>
>
>
>
>
> [USMA:51594] tonne--yeah, right
>
> Paul Trusten
> Fri, 06 Apr 2012 08:35:12 -0700
>
> To me, "metric ton" is cognate with "metric yard" for "meter." I have always
> voted for the megagram. Although they are recognized within the SI, "tonne"
> and, for that matter, "hectare," are throwbacks to pre-metric units. But,
> that's just me.
>
> Paul T.
>
>
>
