Winter solstice


Daylight defeats darkness

You go along, minding your own business, sure in your mind that you understand things, and Bam! Kerpow! Just like that, nature takes you down a peg.

Today is the winter solstice, the day with shortest period of daylight. From today on, the daylight hours will lengthen. Never having given it a lot of thought, I always assumed that this happened because sunrise arrived a bit earlier and sunset arrived a bit later, prolonging the daylight hours.

shock and awe

This morning I went searching the web for the official sunrise and sunset times and discovered to my shock and awe that it's not so simple. The latest sunrise in Palm Springs (6:52am) will not occur until January 4th! Furthermore, the earliest sunset in Palm Springs (4:37pm) took place December 9th! (data [PDF])

Gadzooks! The fine folks at the Naval Observatory explain that "two effects determine the times of sunrise and sunset: the Equation of Time and the Sun's declination" and that each of those changes at a different rate. The Dark Days of Winter.

I've at least heard of the sun's declination, but equation of time? What's that about?

How inconvenient to have facts disturb my cherished spheres of ignorance when there's traveling to be done, friends to see, and celebrations to be observed!