Happy Winter Solstice

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Image from Will Kinney@WKCosmo

Image is of an Analemma

The shape of the Analemma is due to change of declination and the equation of time.

The north–south component of the analemma results from the change in the Sun’s declination due to the tilt of Earth’s axis of rotation as it orbits around the Sun. The east–west component results from the nonuniform rate of change of the Sun’s right ascension, governed by the combined effects of Earth’s axial tilt and its orbital eccentricity.[1]

One can photograph an analemma by keeping a camera at a fixed location and orientation and taking multiple exposures throughout the year, always at the same time of day (disregarding daylight saving time).

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I’d forgotten about this:

a Rev. Mr. Miner, of Canada presented a paper called “The Snow Line” in which he observed, “Should a man start from the Tropic of Cancer at the winter solstice and walk 18 miles per day northward for six months, his shadow would remain nearly the same each day at noon.”