I should add: Didn't someone say that the oldest sundial known was a Chinese Equatorial Dial marked for Equal Hours?
Anyway, in Europe, equal hours have been in use for, what, around 700 years? But, if I correctly remember what i read, Temporary Hours were in use in classical and ancient times, for more like 2700 years or more. On Mon, Jul 27, 2015 at 11:45 PM, Roger Bailey <[email protected]> wrote: > Hi Dan, > > Don't worry, 60 is well represented in time and angular measurements. We > have 60 minutes in an hour, 60 seconds in a minute, 6 x 60 degrees in a > circle and again 60 minutes in a degree and sixty seconds in a minute. > Why? Being highly divisible is only part of the story. Other parts include > our year of 365.25 days, very close to 360 and six equilateral triangles in > a circle indicating that pi was close to 3 but greater as the arc is longer > that the cord. If a circle is 360, equilateral triangles are 60 and a > quadrant is 90. My preference for angular measurement is degrees and > decimal minutes as opposed to degrees, minutes seconds or decimal degrees, > From navigation experience, I recognize a minute of latitude is a nautical > mile. I can easily handle decimal miles. I hate grads using 100 rather that > 90 in a quadrant. Some French topo maps still use the Paris meridian for > longitude and grads for latitudes. This is as ridiculous as republican > time, 10 hours in a day, 100 minutes in a hour and 100 minutes in an hour. > Get over it as the French did with time. The Babylonians were onto > something when they defined our base 60 units of measurement. > > Regards, > Roger Bailey > > *From:* Dan Uza <[email protected]> > *Sent:* Monday, July 27, 2015 2:59 PM > *To:* [email protected] > *Subject:* Precision: the measure of all things > > Hi everyone, > > If you haven't already, you might want to check out the first part of the > documentary "Precision: the measure of all things". It's about the > measurement of time and length, featuring the topic of sundials. There's an > interesting theory about how the day got split into 12 hours because this > number is highly divisible (but why not 60?). I just watched it on Da Vinci > Learning. > > Dan Uza > Romania > > ------------------------------ > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > ------------------------------ > > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2015.0.6081 / Virus Database: 4392/10318 - Release Date: 07/27/15 > > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > >
--------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
