Good calculation Thom. It's not the revolutional speed of the earth it's the
precessional speed. It is the fastest at the equator and the dwell time is
longest at the summer and winter equinoxes.
The rate of change of a sine wave is a cosine wave. The cosine function is
at a maximum of 1 when the argument is at 0 degrees. The argument used in
the sine function for position should be the number of days away from the
day with equal dark/light normalized to k*pi radians. The k is to fudge for
complete darkness near the poles.
It is extremely gratifying to see what is possible under the tutelage and
inspiration of our own learned Master Mariner, the good Capt Neal. Ole Thom
has clearly demonstrated that, good thinking Ole Thom!
Amen!
Bob Crantz
"Thom Stewart" wrote in message
...
Wally,
Admittedly my method is very crude but with 5 degrees to go to the
Equinox that is about 3.3 days per degree and at this section of the
seasonal sine wave that does sound rather fast for the revoltional speed
of the earth.
3.9 was what I figured. That would be about .26 degrees a day. We'll
know in about 15 days won't we?
4 equal seasons divided into a 365 day year would 91 1/4 days. At 3.3
days per degree the seasons would almost be 72 1/2 days long. I could be
wrong and I know the rate varies ( Sine Wave) but I'm pretty sure the
rate of change is the fastest crossing the Equator. My method is a
guessation and I use the RMS rate for my guess. We'll see. 1.1 degree (
60 miles +) in 75 days using no instruments and no tables, I'm pretty
happy with the results
Keep in touch
Ole Thom
http://community.webtv.net/tassail/ThomsPage