Today the Sun Stands Still

Today is the real reason for the season: It's the winter solstice! If you're a purist, then raise your glass at 23:03 UTC (18:03 Eastern US time), because that's the moment the solstice occurs. There are a lot of ways to look at this, but they all boil down to the Earth's axis being tilted with respect to its orbit. You've seen this with classroom globes; they're tipped by about 23.5°. As it orbits the Sun, the north pole of the Earth's axis is always pointed pretty close to Polaris in the sky,...