Subject: | Age of moon not linear with phase (as previously noticed) |
Date: | Sun, 10 Nov 2013 20:31:37 -0700 (MST) |
To: | bug-Astro-MoonPhase [...] rt.cpan.org |
From: | Barry Carter <carter.barry [...] gmail.com> |
I'm surprised that over 5 years have passed w/ no one replying to:
https://rt.cpan.org/Public/Bug/Display.html?id=45698
I noticed this error too:
- phasehunt(1384063127.11639) shows that there's a quarter moon at
1384063127.11639 (which is why I chose that value), and a new moon at
1383482972.79007.
- This makes the quarter moon 580154.32632 seconds, or 6.7147491472 days old.
- However, phase(1384063127.11639) shows the moon's age as 7.37516501873563
days.
I think the code assumes the moon's phase and age are linear functions of each
other. For example, if you multiply the moon's incorrect age by 4, you get
29.50066007494252, the moon's synodic period.
I actually thought this myself, but it turns out to be incorrect for pretty
much the same reason the sun follows the equation of time.