In Astronomical Algorithms, Meeus gives a table for periodic terms for nutation in longitude (Δψ) and obliquity (Δε) according to the 1980 IAU Theory of Nutation. I'm unclear how the table should be used. Do I:
Use each row to generate the argument of trig functions, presuming D, M, M', F and Ω...
I want to lay out an analemmatic sundial, with a true figure 8 analemma for the gnomon position instead of the more common date marks. Everything I read shows that the ordinates of the points on the curve are a function of the sun's declination on a given date. Further, I'm also given to...
Apologies. Didn't see this thread until today and didn't see the date, either.
Anyhow: I know of two articles published about 9 years ago that address these topics pretty well. Send me a PM with your e-mail and I can provide PDFs of these articles if you're interested.
Assuming you're after fairly rough-and-ready engineering values, I'll try offering some comments:
1. The enthalpy of fusion is a rather weak function of temperature. For most engineering purposes, assuming it's temperature independent is not a bad approximation.
For the rest of the...