Bad Astronomy

Halo, how ya doin’?

The other day I was walking across the campus here in California, and I saw a nice halo around the Sun. Well, really only the top half of the halo; the bottom half was cut off because of clouds. Halos are really pretty– ethereal circles of diffuse light around the Sun caused by sunlight bending around inside of ice crystals in the air. It’s getting late in the season for halos, because soon enough it’ll be too warm for ice crystals. So it was a nice surprise to see one.

The best one I ever saw was a couple of years ago. I had just dropped my daughter off at school, and glanced up in the sky. The halo was vivid, as if it were etched into a crystal hemisphere. It was flanked by two teardrop-shaped flares of light called parhelia, or more often called sundogs. The sundogs stretched out to either side, focusing into lines of light that shot straight out, parallel to the horizon, nearly halfway around the sky. I had never seen the like.

I was stunned, mesmerized by what I saw. It was beautiful. See for yourself: I took the picture above of the event (click on it for a bigger version). You can see the sundogs and everything. It was a real stunner. To be honest, this image is actually a mosaic of several smaller shots, combined by an artist with whom I work.

Anyway, I ran back inside the school to grab the kids and show them the halo. They all “oohed” and “ahhhhed”, and I explained how the ice crystals bent the light and all that. After a while they went back in, and I started home. On the way back, I saw a woman I knew vaguely (I see her a lot on the way to dropping off my daughter). I showed her the halo too. Her reaction was not what I expected.

She gasped, looked at it for a moment, and then asked me, “What does it mean?”

I gawked at her for a second. “What do you mean, ‘what does it mean’?” I asked.

She looked right back at me. Her tone was more plaintive. “What does it mean?” she repeated.

“It doesn’t mean anything,” I replied. “It just is.”

She watched me for a moment, then turned back to the sky. I waited for her to say something more, but when she didn’t, I began walking back home again, leaving her to try to extract some sort of purpose from a random event.

Humans are pattern-seeking animals, and we constantly look for meaning in our lives. I don’t think that halo really meant anything. It wasn’t a sign, an omen, a harbinger, or a portent of anything.

What it was, was pretty. And interesting, in a scientific way, but really, it was just very pretty. Can’t that be enough?