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Solar Energy and Time

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The Ernie Wirtanen Interest Fund

This is a charming example, in 12 frames, of the relative intensity of solar energy received by the Northern hemisphere during our planet’s annual tilted spinning trip around the Sun…taken in a single day in the Arctic, by Anda Bereezky, in 2005.

The I Ching, one of the Chinese Classics, attributes a “hexagram” to each of the months of the year, describing appropriate behaviour as the light waxes then wanes. Although theirs is a lunar calendar (beginning the second new moon after the Winter Solstice) their year runs roughly from mid-February to mid-February. Here, we might want to move the last pane to the left to match that progression exactly.

Sunlight pattern for a year in Northern hemisphere caught in 12 photos of an Arctic 'day'.

The Midnight Sun, by Anda Bereezky, 2005

After the return of the light, the solar energy we receive continues to mount until it hits its peak in the Summer solstice, and then begins its steady decline during our annual orbit.

What I like about this “year” is that it doesn’t drop you off in utter darkness but leaves you with the rising light. Different behaviors are appropriate for different times of the year, particularly in an agricultural society, reliant on solar energy for food crops. The I Ching details those to some extent.

Hexagram 49, while outside the dozen that make up the monthly changes, has an “image”:

Fire in the lake: the image of REVOLUTION:

Thus the superior man

Sets the calendar in order

And makes the seasons clear.

(source: p 190, “The Book of Changes”, Wilhelm/Baynes edition, Bollingen, 1950)

In line with “making the seasons clear”, this time-lapse video of four seasons: