It seems from the choice of symbols throughout the SI that the potential use of the same symbol for a both a prefix and a unit is, in the main, studiously avoided. For example 'Pa' for pascal rather than just 'P' and 'cd' for candella instead of just 'c'. There are two exceptions 'm' and 'T' (tera or tesla).
I did say "maybe" and didn't claim it was absolutely necessary. I merely reflected what may have inhibited the adoption of 'K' for kilo in the light of the general pattern. The notion of elegence is a subjective one and I am personally inclined to prefer that prefixes and units should have different symbols. ----- Original Message ----- From: "Bill Hooper" <[email protected]> To: "U.S. Metric Association" <[email protected]> Sent: Thursday, 17 June, 2010 1:36:43 AM Subject: [USMA:47828] RE: The Oil Leak (Estimate) Increases Again On Jun 16 , at 8:23 AM, Phil Hall wrote: As for 'k' for kilo maybe that is because of the 'K' for kelvin (context would resolve ambiguity but it wouldn't be very elegent). With hindsight it may have been better to use 'k' for kelvin and 'K' for kilo There would be no ambiguity (or lack of elegance) if the capital "K" would be adopted as the symbol for "kilo–". The "k" for "kilo-" is a prefix. The "K" for "kevin" is a unit name. A capital-K COULD be used for both without any difficulty. There already exists another such combination which is used by all without any trouble; that is, the letter "m". The lower case "m" is used for both "metre" and "milli-", even to the quite common example of millimetre "mm". The distinction between the symbol "m" for "meter" and the "symbol "m" for "milli-" is clear from the use. If the "m" is a prefix, it is "milli-"; if it is a unit symbol it is "metres". Similarly, if "K" were adopted as the symbol for the prefix "kilo-" (and also used for the unit kelvin), no one should have any trouble understanding that Kg would stand for kilogram, not kelvin-gram. (The symbol for kelvin-grams would be K⋅g .) Even if the capital "K" were used for "kilo-" as well as for kelvins, no one should anyone have a problem with expressions like µK, which stands for microkelvins, not "micro-kilos" (whatever that could be). And surely, "KK" would be as easily recognized as meaning kilokelvins as mm is recognized as millimetres. Bill Hooper 1810 mm tall (That's "millimetre", not "metre-metres".) Fernandina Beach, Florida, USA ========================== SImplification Begins With SI. ==========================
