This is the problem with "day" as a colloquial unit. You are referring to a sidearal day (one complete rotation with respect to the star field) as opposed to the solar day (one complete rotation with respect to the Sun) that Bill referred to, John.
Surely this is the reason that the BIPM took pains to define "day" as them meant the unit to mean when used with SI units. Jim kilopascal wrote: > > 2002-03-31 > > I thought the day was actually shorter than 24 h. The day is 23 h 56 min > long. Something like that. So, the true day is 4 min shorter than the 24 h > day. > > John > > ----- Original Message ----- > From: "Barbara and/or Bill Hooper" <[EMAIL PROTECTED]> > To: "U.S. Metric Association" <[EMAIL PROTECTED]> > Sent: Sunday, 2002-03-31 07:54 > Subject: [USMA:19167] Re: kWh and time definition > > > on 3/27/2002 1:04 PM, Ma Be at [EMAIL PROTECTED] wrote: > > (Regarding the definition of the second and the non-integral number of > > seconds in a day or in a year...) > > > The only problem is that we may not find a way to circumvent the fact > that > > > there are 365.xx days in a year... > > > > Nor can you circumvent the fact that there are not 24 hours in a day. The > > average day is a bit longer than 24 hours (currently) and it fluctuates > > regularly during the course of a year and irregularly over the span of > many > > years (so in the future the day might be shorter than 24 hours, and not > > necessarily "average out"). The current extra length of the day ha > required > > the adding of a leap second every few years. The length of the particular > > day when the leap second is added is 24:00:01 (hh:mm:ss). > > > > There is NO WAY that ANY time unit can be divised that is BOTH constant > and, > > at the same time, a simple and FIXED FRACTION of the day or the year (or > > month, week, fortnight, etc.). It is impossible because NONE of the time > > intervals based on motions of the earth is constant. > > -- Metric Methods(SM) "Don't be late to metricate!" James R. Frysinger, CAMS http://www.metricmethods.com/ 10 Captiva Row e-mail: [EMAIL PROTECTED] Charleston, SC 29407 phone/FAX: 843.225.6789
