Responses interspersed. >I used km/ks as a comparison with km/h, keeping the top unit the same, >instead of 27800 km/s.
That's somewhat fast. In fact it's almost one tenth of the speed of light. Gotta watch that decimal point. >The problem with your explanation is that you say it "makes sense" to use >hours only because "you know" hours. You could just as well say that it >makes sense to use miles because you know how many miles it is. I didn't say anything about knowing hours. I referred to knowing how many hours it is to the destination. >That is not a good argument for not converting to metric units. Most Americans would >not be able to easily calculate their travel time from km/h, because they >use miles, but does that mean that they should continue to use mph? I'm not sure what your point is, here. I wasn't arguing for conversion to metric units. Using metric units is a given on this list server, with no argument in favor being necessary. Americans would, in fact, find it just as easy (exactly as easy, in fact) to calculate travel time from their speed in km/h as they do now from their speed in mph. That is, assuming they know how many kilometers it is to their destination. The whole point of conversion (metrication) is getting people used to thinking >metric. They should be able to wrap their minds around m/s just as you >expect them to switch from miles to kilometers, if they get used to using >kiloseconds, as well. The 95% of the world that uses metric almost exclusively has its collective mind wrapped around km/h, not m/s, for travel. Meters per second make a lot of sense for wind speed. You can visualize the leaves blowing down the road at 10 m/s, for example. The speed with which a baseball pitcher throws the ball lends itself perfectly to m/s. An analysis of a collision between two cars should almost certainly involve an estimate of the closing speed in m/s. One could cite examples ad nauseam. >I'm aware that the hour is accepted for use with SI, but it is still not a >metric unit. It is not a multiple formed by adding a prefix to the base >unit of time interval, nor is it a derived unit. And it is not just the >common people who use these "accepted" units, i.e. minutes, hours and days. >These units are used by scientists, as well, instead of kiloseconds, etc. Whether they are used by scientists depends on which field of science is involved and to whom the scientists are talking. Among themselves, they may very well say that the Universe is about 7.9 Ps (petaseconds) old. In communicating with non-scientists, they are more likely to say 15 billion years. Their audience thinks in terms of birthdays, new year celebrations, anniversaries, historical dates, etc. Do you prefer to talk about the War of 1812 or would you prefer to date it by the age of the Universe, in petaseconds, at the time it happened? (I'm taking some liberties in citing that as an example, as the age of the Universe is only an estimate.) It just seems ironic to me that we aren't considering kiloseconds >along with the rest of the metric system. That may be because we have several billion clocks, watches and other timekeeping devices. We also have billions of historical documents in which the time was recorded in the same manner as today. The 24/60/60 scheme is far more entrenched than Imperial or U.S. Customary ever was. The day is based on a natural interval >(although the SI day is defined as being exactly 86400 SI seconds) >but hours >and minutes have no basis in nature and we could probably get used to using >kiloseconds, even though there are not a round number of them in a day. We >could make clocks which count from 00.000 to 86.399 ks, for >instance. Maybe >our TV shows could be made longer or shorter to accommodate a round >number of >ks, maybe 2 or 4 ks instead of 30 or 60 min. One can be a zealot or one can be pragmatic. I think most of us who advocate a massive shift to the metric system are pragmatic. The people at BIPM, ISO, ASTM, IEEE, NIST, and so on, are certainly pragmatic. History is with us with respect to a full shift to SI as it is currently defined -- including units accepted for use with SI (and which are quite clearly not discouraged). History is against us with respect to the everyday use of the kilosecond. I've learned to accept that and am content that the best we can probably do is to encourage the use of the ISO 8601 Standard for dates and times (yyyy-mm-dd hh:mm:ss). If you are still not convinced, perhaps you'd like to outline for us a public relations and educational campaign to convert the entire world from hours, minutes and seconds to kiloseconds and seconds. I would not consider such an outline complete without a full accounting of the probable costs and an estimate of the time it would take. (In doing the time estimate, you should feel free to use megaseconds, gigaseconds, or teraseconds, as appropriate.) Bill Potts, CMS Roseville, CA http://metric1.org [SI Navigator]
