Science Bits: Winter Solstice

The Winter Solstice is coming up soon. Although it’s known as the shortest day of the year, or the first day of winter, I like to celebrate the start of the days getting longer. How does it work?

The Earth is tilted slightly, so that the North Pole is not exactly “up” and the South Pole is not exactly “down”. As a result of this tilt, one side of the Earth is always tilted slightly towards the Sun and one side of the Earth is always tilted slightly away from the Sun. The side of Earth that is tilted towards the sun has more direct sunlight and more hours of sunlight in a day.

The Winter Solstice is usually around December 21 and is the day of the year that the Northern hemisphere is most tilted away from the Sun. The Northern Hemisphere has the least direct sunlight (brrr) and fewest hours of daylight on this day. (Note: Tilt is not the same as distance. This time of year also happens to be when the Earth is closest to the Sun, and it’s still cold. It is more important to the weather forecast that the Northern Hemisphere is tilted away from the Sun.)

Why is that exciting? It means that the Northern Hemisphere, which includes me in New Jersey, is tilted away from the Sun as much as it will be all year, which means on December 22, I’ll be getting slightly more direct sunlight and a longer day. December 23 will have a little more direct sunlight and a longer day. And so on and so forth, until the Summer Solstice around June 21.

This is it. Starting December 21, the days will start getting longer (in the Northern Hemisphere). We will be getting a couple more minutes of sunlight every day. We are on our way towards my favorite season, summer.

I’m not the only one to find the Winter Solstice exciting. Many cultures in the Northern Hemisphere have holidays that celebrate the shortest day of the year, often with a “Festival of Lights” or otherwise displaying lights in the darkness.

Light some lights and let’s start looking towards the end of 2020 and towards next summer, with hopefully fewer pandemics.