Sound like you know what you’re talking about when people ask you why today is the shortest day of the year.
Every year, Dec. 21 or Dec. 22 is the shortest day of the year. Why? Because of the Earth’s tilt on its axis (23.5 degrees), the North Pole and the Northern Hemisphere is tilted farthest from the Sun today. Likewise, the Sun’s path is the farthest north from the Earth’s equator. The North Pole, in fact, is in complete darkness and hasn’t seen the sun in months. It won’t see dawn until March.
(See photos from the lunar eclipse, which occurred on the winter solstice for the first time in centuries.)
The day officially marks the beginning of winter and thus has the longest night of the year. New York City, for example, is estimated to get only 9 hours, 15 minutes and 5 seconds of daylight.
Throughout history, people celebrated the day as they considered the worst of winter to be behind them (never mind that most of the United States has yet to experience the true bluster of winter it usually sees in January and February). But take comfort in the fact that the days will only get longer from here on out.