Originally Posted by
conspiratemus1
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As per
John E, the analemma explains it, and check out the really cool composite photos where one of the exposures (the first, presumably) captures a solar eclipse! The two lobes of the figure 8 are not symmetric, owing to the eccentricity of the earth's orbit.
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I just think it's gratifying that you can use simple observations (aided by timepieces not available until recently in human development, say, mid-18th Century) to take a step toward understanding the true nature of the heavens. (To make an analemma you have to observe the sun at exactly the same clock time every day, a meaningless concept before the naval chronometer.) I'm not embarrassed to say I am profoundly moved by this.
ah yes... the key word is "analemma".
A friend had introduced it to me, but I'd forgotten about it. The wikipedia page is helpful to me...
https://en.wikipedia.org/wiki/Analemma
The page on "mean solar time" helps too.
If I understand correctly, the time when the sun is at the center of its travel from east to west would normally be considered noon, but due to the varying speed caused by the elliptical orbit, it will occur a bit earlier or later than a mechanical clock would predict.
As others have noted too, it's nice to understand the weird figure 8 that would be printed on globes, back when people still had globes.
Steve in Peoria