I track the day lengths using the U.S. Navy data.
In theory, the solstices and equinoxes "should" align with the observed sunrises and sunsets, but they don't.
They would if the Earth didn't have an atmosphere. Sunlight penetrating the air experiences a little bit of refraction; hence, the discrepancy.
Which leads me to wonder. . .
How does one determine sunrise and sunset times on other planets? Especially puzzling for me are the Gas Giants Jupiter and Saturn.
Cheers, PW.
P.S. Thinking about this stuff makes another question pop into my head: "What do people who have real lives ponder?"
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