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Name: Wiz Kid
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: Around 1999
Question:
I am having a hard time visualizing how the equation of time affects sunrise and sunset times so dramatically around the winter solstice. I do understand that the obliqueness of the ecliptic and the earth's elliptical orbit have some affect on apparent solar time, but I just cannot visualize it. Is there a visual tool you can suggest, perhaps a computer simulation program? Or maybe a chapter in a book which explains the celestial mechanics very clearly?


Replies:
Once upon a time there was this guy from the magazine "Sky & Telescpope" and he wanted a visually graphic depiction for the equation of time. So, what he did was he set up his camera pointed at a fixed position (in other words he didn't move it, ever!) and he took a picture of the subn (using the proper filters) each day at precisely the exact same local time. (Remember to account for daylight saving time) What he ended up with is a beautiful elongated figure eight ! This my friend is precisely the equation of time you've been searching for. BTW it is also plotted on the annual "Celestial Calendar" printed in the same magazine each January.

Hope this is of some help.
Johannes Kepler




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