Yokemate of Keyboards
Posts: 2793 from 2006/3/21
From: Northern Calif...
> I wonder how much living at 7,000ft. elevation [...] had to do with the days seeming
> longer. I am sure it has some effect, as you can see the Sun come up a little earlier
> than people at the base of the mountain, or at sea level, and the reverse applies when
> the Sun is setting, but don't know if it is just an extra 15 minutes of daylight, or
> over an hour of extra daylight, being on top of a mountain at an elevation of 7,000ft.
The formula for the additional daylight time t at an elevation e (above sea level) compared to sea level, assuming a spherical earth with radius r, should be:
t = 2 * arccos(r/(r+e)) * 24h/360°
Inserting e = 7,000ft and r = 20,902,231ft results in:
t ≈ 0.2h = 12min
Only 12 minutes! It definitely seemed like more than that, as I often played outside with friends until 10pm (22:00hrs) during the long days of Summer break from school, which always started in the middle to end of June.