An interesting thing about equinoxes

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TimberWolf replied

22 September 2011, 10:40
Originally posted by KentPhilip View Post

Very interesting.

But I think the 6am/pm sunset times include higher latitudes than arctic/antartic circles.
Even if you are 1cm away from the north pole the sun will still set, geometrically speaking, at 6pm assuming you are using the time zone corresponding to the direction away from the pole that you are.

Yes, that's true. I was imagining the 21 December one, forget the name, when the North pole is tipped 23.5 degrees away from the Sun. On which date there would be no sunrise/sunset above the Arctic circle. The Wiki had this right, too. At the equinox, which is what I should have been picturing, there's no tilt, and hence 12 hour days above the Arctic circle on this date too.

Plus the sun rises and sets east and west respectively on this day for the whole Earth, excluding the poles where things get a bit ambiguous.
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KentPhilip replied

22 September 2011, 10:21
Originally posted by TimberWolf View Post

Sunrise and sunset times the world over (except higher latitudes than the Arctic/Antarctic circles) is 6 a.m. and 6 p.m. local time today. Give or take variations listed here (the big ones being that local sun time and local clock time are different, e.g. because of the use of time zones and daylight savings).

And that the days are 12 hours long today, the world over (again with caveats, not least including the refraction of the sun through the atmosphere and that the sun is not a point source).

Quite interesting eh?

Very interesting.

But I think the 6am/pm sunset times include higher latitudes than arctic/antartic circles.
Even if you are 1cm away from the north pole the sun will still set, geometrically speaking, at 6pm assuming you are using the time zone corresponding to the direction away from the pole that you are.
Leave a comment:
TimberWolf started a topic An interesting thing about equinoxes

22 September 2011, 09:20
An interesting thing about equinoxes

Sunrise and sunset times the world over (except higher latitudes than the Arctic/Antarctic circles) is 6 a.m. and 6 p.m. local time today. Give or take variations listed here (the big ones being that local sun time and local clock time are different, e.g. because of the use of time zones and daylight savings).

And that the days are 12 hours long today, the world over (again with caveats, not least including the refraction of the sun through the atmosphere and that the sun is not a point source).

Quite interesting eh?
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