A Great Math Site: Understanding the Analemma


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When I was a kid I remember reading about this pattern. I never knew it
was called a, what, Analemma??? Anyway, Check out [this

post](http://scienceblogs.com/goodmath/2006/12/a_great_math_site_understandin.php) from Good Math, Bad

By way of the astronomy
picture of the day
, I encountered a
really fantastic site about the analemma.

The analemma is the apparent path that the sun takes in the sky during
the year. If you record the precise position of the sun at the same
time every day, instead of being in exactly the same place every day,
it will traverse a figure eight, like in this image. This is an effect
caused by a combination of the eccentricity of the earth's orbit, and
the tilt of the earth's axis. It can be a bit hard to visualize just
where the figure-eight shape comes from; the analemma site uses a
combination of diagrams and animations to make it extremely clear, and
works through the entire process of demonstrating where each component
of the analemma comes from, and deriving the equations that describe
it. Read
the comments on this post…

Enclosure: sky1.v01.small.JPEG
(3.1 Kb)

(from: A
Great Math Site: Understanding the Analemma