What makes sunrise and sunset times?

[conuly]

Oh, don't give me "earth's rotation" and "angle of the sun", I know that! But...

Look, I googled to find what time sunset was in NYC, found out that today it's 4:55. Sunrise was at 7:17 Okay, fine.

But in Anchorage it's sunrise at 9:52, but sunset only at 4:27. The sun rises two hours later there, but it only sets about thirty minutes earlier? I'd always assumed it was constant - if it rises an hour later, it sets an hour earlier, that sort of thing. And over in Honalulu the sun rose at 7:12 (barely earlier than here in NYC) but it doesn't set until 6:12. Maybe my problem is in viewing my own city as the default, and if I viewed these times as varying from the equator (or the North Pole) they'd make sense? I understand that summer and winter are more dramatic closer to the poles, and less dramatic close to the equator, but... like I said, I thought you took from both sides of noon more or less evenly wherever you were.

Comments

[ysobel]

It's all about the earth's rotation and angle of the su--

oh. not that. right. *grin*

My not-very-well-informed grasp of the matter is that a) it's affected by latitude (northerer locations have shorter days [in winter in the northern hemisphere &c.]) and b) solar noon rarely is the same as clock noon.

So the length of the solar day varies because of the first point (9h38 at New York's latitude, 6h35 at Anchorage's, 11h at Honolulu's), but there's some wobbliness as to where solar noon is (which might be related to longitude or to relative position within the time zone or something) -- and it probably averages out over the course of the year.

*squints*

That wasn't at all helpful, was it? *g*


I would imagine that at other times of the year,

[conuly]

At other times of the year what?

[ysobel]

...well, I would tell you, but then I'd have to kill you. >_>