On 2004 Jul 16 , at 8:39 PM, Pat Naughtin wrote:
An argument that might be used to retain lower case k as the symbol for kilo
is that it can be useful to distinguish it from upper case K for kelvin.
For example, if you wish to write 2000 kelvin, you might write:
2 kilokelvin or 2 kK.
There is no need to "distinguish" the symbol for kilo from the symbol for kelvin.
Since a prefix is never supposed to be used alone, the capital K alone would always mean "kelvins". If the symbol for the prefix kilo were to be changed from k to K, then a capital K alone would STILL mean kelvins. If the change were made, then the symbol for kilokelvins would be "KK". Clearly the first "K" is a prefix and the second one is the main unit. How could it be misconstrued to be anything else?
This "problem" is not any different from the case of the lower case "m" which is used both for the unit "metre" and also for the prefix, "milli"*. Clearly, "m" alone means metre, "mm" means millimetre and if "Mm" is used it means megametre. If "MM" or "mM" is used, or if "M" is used alone, it has no meaning in SI. All this is clear to those who know the rules. It will never (I'm afraid) be possible to eliminate the possibility that some people do NOT know the rules and use the symbols incorrectly, no matter what the symbols are.
It is true we would have trouble with people who do not know that capital letters and lower case are not interchangeable SI symbols (and therefore wrong symbols like "ML" for millilitres is often seen) but that is a problem that occurs now and will (unfortunately) continue to occur whether or not the kilo symbol is changed from k to K.
Regards,
Bill Hooper
Fernandina Beach, Florida, USA
*How many other example are there where a prefix symbol is the same as a unit symbol? There is "T" for the prefix terra and also for tesla, the unit of magnetic flux density. That's the only other one I can think of. There are a couple others like P for the prefix peta with Pa for the unit pascal, but that's not quite the same thing since the unit symbol is a two letter combination.
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Make it simple; Make it Metric
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