As well as being pure, SI has to fit everyday life, or it will be laughed out of existence by those who don't want to make the change. Everyday life includes noting how far it is to a destination, knowing your speed in the same units, and thereby figuring how long it will take you to get there.
Distance to Omaha 650 km My speed 100 km/h It will take me 6.5 hours, not including gas stops, pee stops, food stops. I would have a much harder time figuring this in m/s. We can go down with the ship if we insist on absolute perfection. Carleton -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Gavin Young Sent: Wednesday, February 18, 2004 12:54 To: U.S. Metric Association Cc: U.S. Metric Association Subject: [USMA:28765] Re: second based on decimal day If hours are not considered a derived unit of the SI second and thus a part of SI, then why does the USMA and SI promote using kilometers/HOUR (km/hr) in place of miles/hour? If the hour is not considered a derived SI unit, then the USMA and SI should be promoting only saying kilometers/SECOND or meters/SECOND - instead of promoting use of the term kilometers/HOUR!!!! Why does the USMA tell people to use km/hr for road signs if the hours are not considered part of SI??? If hours are not a part of SI, then you are not following your own admonitions when you use the USMA server to promote use of the term km/hr. Hence the inconsistency of the time units being promoted by USMA and and many SI promoters, thus the need for decimal (aka "metric") time units! If the inconsistency or flaw of using hours does not exist in SI, then it exists in those who are promoting the use of the term kilometers/HOUR as a part of proper SI usage!!! Lets fix the SI system by using decimal time units, or at least insist on using m/s instead of km/hr!! Quoting Bill Hooper <[EMAIL PROTECTED]>: > [EMAIL PROTECTED] wrote: > > ... you seem to prefer to swallow up (or put up) with this clear flaw > > in the SI system > > Sorry, but days, hours and minutes are not part of SI and have never > been intended to be. They do not represent a flaw in SI. If anything, > they represent a flaw in the way we measure the time of day. The uses > to which scientific and technical time measurements (and units) are > used are so different from the ways in which time of day is used that > there does not seem to be any reason why the two need to be (or can be) > coordinated or reconciled. > > It's not a flaw in SI because it is not part of SI at all, and > therefore is not of much interest to proponents of SI (many of whom are > members of USMA and subscribers to this list). > > Regards, > Bill Hooper > Fernandina Beach, Florida, USA > > Gavin Young http://www.xprt.net/~hightech , http://www.renewableelectricity.com, http://www.electric-automobile.com
