As I was walking home last week I noticed a rainbow reflected in the windshields of a series of cars. I like rainbows - not in a kittens and Care Bears "I wuv you!" sort of way (okay, I admit it - I like kittens…with a nice chianti…no, I'm kidding, I really do like kittens, for petting an cuddling and stuff and not for eating, not even as a snack, not even if I have low blood sugar), but in a Fun with Physics, check out that there keen optical phenomenon way. So of course I wheeled around to see it up in the sky.

But I couldn’t find a rainbow.

Which meant I had to come up with a hypothesis to account for the fact that car after car had a rainbow reflected in its windshield.

Hypothesis 1: The windshields are reflecting a banner of some kind.

So I looked for the banner. No banner.

Hypothesis 2: All the cars have some sort of polarized window tinting, and that somehow explains the rainbow.

That car has untinted windows, and it's got a rainbow. Damn.

Okay, get more data.

Say - that old VW bug isn’t reflecting a rainbow at all, and the window is much more perpendicular than the others, which means, based on the angle of reflection, I really ought to looking somewhere in the neighborhood of, oh, straight up.

And there it was - more like a piece of ribbon than a bow, but still very red, orange, yellow, green, blue, indigo, and violet.

Hey, check out these cute kittens!