The Darkest Evening of the Year

According to timeanddate.com, sunset tonight is 5:27 p.m. Eastern Standard Time, after 9 hours, 30 minutes, and 22 seconds of daylight. These are the same vital statistics we had last year.

Winter solstice in Corydon this year is 4:48 p.m.

I am late to the science party, but I think I have finally understood that this means, technically, that 4:48 p.m. is the moment, as measured by the clock, that the earth’s north pole reaches its maximum tilt away from the sun, as it orbits the sun, while spinning on its slightly tilted axis of rotation.

Which axis, again I think I have now really understood, perhaps once again after having forgotten it in the interim, is always tilted. With respect to … some imaginary axis that would not be tilted, I suppose. So the earth does not actually keep re-orienting itself with respect to the sun, sometimes standing nice and straight, sometimes reclining or bending over backwards. It’s that, being permanently tilted and orbiting the sun in the particular way it does, that permanent tilt is sometimes towards and sometimes away from the sun, and sometimes more or less parallel.

What I also learned this year, definitely for the first time, is that all these astronomical spatial relations mean that there is something called an “equation of time.” This is the equation that relates the length of the “apparent solar day” and the “mean solar day.” That’s “mean” as in “average,” not “unkind.” Although, when the apparent solar day is longer than the mean, the mean day might feel a little stingy. But it would make up for that with its generosity on the days when it is longer than the apparent one.

All this striving to understand amounts to a way to take my mind off the absence of sunlight.

Which doesn’t last, thank God. Who made that equation of time. And every kind of time. And the light. And in whose light we see it.

Stopping by Woods on a Snowy Evening, by Robert Frost.

[Plenty of commentary on the internet; here’s mine.]

Image: “Las Golczewski zima,” Radosław Drożdżewski (Zwiadowca21), CC BY-SA 4.0, via Wikimedia Commons.

4 responses to “The Darkest Evening of the Year”

      • Snow here starts this afternoon. It’s -10 now and the winds will kick in tonight. Wind chills colder than -40 expected. Praying our youngest who lives 3 hours north of us didn’t attempt a dangerous drive home.

        Liked by 1 person

      • Praying with you.

        We used to live in Michigan, and then in Chicago, and those numbers echo some painful memories. Down here in the LOWER Midwest people are fretting over predictions of -2. Bad enough. Our plans for holiday travel to Dayton are on hold waiting to see how much snow, or ice, we actually get – no dangerous drives for us.

        I grew up in Southern California, so “white Christmases” hold no nostalgia for me. And there’s such a thing as too much white! So I suppose prayers are in order for everyone to get through this as safely and warmly as possible.

        Liked by 1 person

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