But I’m trying to figure out why sunset and sunrise aren’t perfectly symmetrical. I mean, I get that local noon isn’t at clock noon (except for at one longitude within a time zone) but it all seems like constants to me:
So how can it be that (noon – sunrise) != (sunset – noon) ?
Update: Last night was an open house at the Canada France telescope and I got the lowdown from a professional. Noon is defined as when the sun is at the zenith, but because the Earth has moved in its orbit, it has to rotate slightly more than 360 degrees to bring the sun directly overhead. Not only that, because the Earth’s velocity in its elliptical path varies based on how far from the sun we are (Kepler’s laws of planetary motion), the amount of rotation needed to get from noon-to-noon (in other words, the actual time of a day) varies very significantly — 15 minutes between the solstices! So those are your two asymmetries.
Oh, man! I just discovered that one of my most-used public addresses (from email.com) somehow “forgot” that it’s supposed to be forwarding my mail to a real account. And, of course, since it’s a public address, my Inbox quickly overflowed with offers of Rolexes and ph@rm4sootikals. So, if you’ve sent email to that lobrien address since, apparently, late October, I haven’t received it. Please resend: I wasn’t ignoring you, promise! (Darn! Now it’s too late to get that low rate mortgage!)