I’m safely back home in England now after my trip to Japan and China.
I didn’t sleep much on the outbound flight from Amsterdam to Osaka. Once the meal was cleared and the lights dimmed I tried to, but kept finding myself watching the flight information screen, which alternated between a map of our current position and the details of our altitude, distance to destination, ground speed, etc. The language of latter cycled between Dutch, English and Japanese.
I noticed that whereas in Dutch and English kilometre was abbreviated to km, as you would expect, in the Japanese it was abbreviated to キロ, which is the katakana for ki-ro.
I mused on the fact that in English kilo ˈkiːləʊ is used as an abbreviation for ‘kilogram’ but not for ‘kilometre’. Is this true for AmE as well as for BrE? And why do we say unabbreviated kilogram with kɪ- but its abbreviation with ki:-? (Is this also true of AmE?) And why, as an abbreviation for ‘kilometre’, but not for ‘kilogram’, or for that matter ‘kilohertz’, do we say just K keɪ? To these absorbing questions I do not know the answers.
Then I further noticed that in giving our altitude ‘metre’ was written unabbreviated in Japanese, as メートル me:-to-ru. Its form suggests that Japanese must have borrowed this word from French (mètre mɛːtʁ(ə)). If it had come from English, it would presumably have taken the form ミーター mi:-ta:.
I believe that in Japanese, as in Chinese, ‘metre’ can also be written with the Chinese character for ‘rice’, 米 , which in Chinese is mǐ.