Regardless of who has the best answer (and I seem to be farthest from
the mean) we are talking about *very* small errors, which was what my
last post was about. Here I've converted the errors to seconds of
time, and you can see that they are never more than two seconds for
the sampled times. I don't suppose a typical sundial can detect a two
second error...
> The following was computed by xephem using the same formula (and
> same observation station!).
date / time (UTC) | EOT (hours) | EOT (seconds)
4/15/1999 23:45:00 | -0.00055181 | -1.98651600
4/16/1999 0:00:00 | 23.9995 | -1.8000
4/16/1999 0:15:00 | -0.000468766 | -1.687557600
4/16/1999 0:30:00 | -0.000427248 | -1.538092800
4/16/1999 0:45:00 | -0.000385731 | -1.388631600
4/16/1999 1:00:00 | -0.000344213 | -1.239166800
4/16/1999 1:15:00 | -0.000302809 | -1.090112400
4/16/1999 1:30:00 | -0.000261292 | -0.940651200
4/16/1999 1:45:00 | -0.000219888 | -0.791596800
4/16/1999 2:00:00 | -0.00017837 | -0.64213200
4/16/1999 2:15:00 | -0.000136967 | -0.493081200
4/16/1999 2:30:00 | -9.55628e-05 | -0.3440260800
4/16/1999 2:45:00 | -5.4159e-05 | -0.194972400
4/16/1999 3:00:00 | -1.27552e-05 | -0.0459187200
4/16/1999 3:15:00 | 2.86486e-05 | 0.1031349600
4/16/1999 3:30:00 | 7.00524e-05 | 0.2521886400
4/16/1999 3:45:00 | 0.000111456 | 0.401241600
4/16/1999 4:00:00 | 0.000152746 | 0.549885600
Also please note, I may be off by a minus sign on EOT (I gave up
trying to keep that straight). The equation the above table evaluates
is
> "Sun.HA"+12-"UT"
> (that's "hour angle of the sun" + 12 - "universal time").
Jim
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| Jim Cobb | 540 Arapeen Dr. #100 | [EMAIL PROTECTED] |
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Truth, like gold, is to be obtained not by its growth, but by washing
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