… but enough about me

Today was the first full day of spring. It’s the vernal equinox — in the northern hemisphere, at least.

The word “equinox” reminds me of two things. The first is my birthday, because it falls around, and sometimes smack dab on, the autumnal equinox, six months opposite the vernal.

Galileo was close. [nasa.gov]

The second is Matthew Modine, because he was in a movie called Equinox in the mid-’90s, which I never saw. I had a big crush on him as a lad. Oh, how I loved to watch him jump rope in Vision Quest. As a kid I found those one-piece wrestler get-ups to be pretty … evocative.

Technically, the equinox is one of two times during the year when day and night are the same length all over because the sun is directly above the equator. You can read more about it and find head-aching terms like “ecliptic equator” and “celestial equator.” All it really means is that we now have a reason to be impatient with the weather for every day we go lower than 60° F. It’s spring, dammit!

I wonder what you would see at the poles on the equinox. Twenty-four hours of sunset?

Pretty close, according to what I read on Wikipedia, which I have no reason at present to doubt. As far as I can figure, we’d see 24 hours of just-before-sunset. These astro-mathematical models work for perfect spheres with no atmosphere in cold, empty space. But real life isn’t so simple. Apparently, day is always longer than night. Because the sun is a huge ball of fire in space, not a single point, when it sinks halfway down past the horizon it’s still day time. Also, because the atmosphere refracts light, it will actually bend the sun’s rays around the curvature of the earth, which is why you can still see for a few minutes after the sun sets.

It’s a good thing the poles aren’t so hospitable to humans, or we’d have a heck of a time getting to work on time.