Just 14 days from today will be the shortest day of 2021. December 21st will still be 24 hours long, but daylight will be in short supply … unless you’re lucky enough to live in the Southern Hemisphere, where winter and summer are reversed, and you’ll experience the exact opposite – the longest period of sunlight of the year.
To more fully understand this phenomenon, you need to know a few simple facts:
- The earth orbits the sun
- The orbit is not circular, it is elliptical – which means that the distance between the sun and the earth varies
- The earth and the sun are not parallel. The earth has a 23.5° slant
- The earth is divided into 2 hemispheres, the Northern Hemisphere and the Southern Hemisphere. The line of demarcation between them is the equator. Parallel 360° circles above and below the equator are called latitudes
Why does this matter?
December 21st is the day during which the North Pole, at the very top of the Northern Hemisphere, is tilted the farthest away from the sun and, hence, the day with the least amount of sunlight. Starting on December 22nd, the tilt will slowly but gradually lessen and there will be more sunlight. On June 21st the cycle will be complete, with the most daylight of 2022, and then the cycle will repeat itself: days will shorten, with fewer and fewer hours of sunlight, culminating, once again, in the darkest day of the year on December 21, 2022.
Most people consider December 21st to be a whole day, which they call the Winter Solstice, Hiemal Solstice, Hibernal Solstice, the Longest Night and/or the first day of Winter; however, the actual Solstice actually occurs at a specific moment, when the sun is exactly overhead a defined latitude (the Tropic of Capricorn). In 2021, the exact time of the Winter Solstice will be 15:50 UTC (Coordinated Universal Time, previously known as Greenwich Mean Time, GMT). The UTC scale is maintained by the Bureau International des Poids et Mesures (BIPM), and is also known as Z Time or Zulu Time. Since the UTC is 5 hours ahead of the East Coast, the actual moment of the Solstice to keep in mind is 10:50 EST (UTC-5); likewise, it’ll occur at 7:50 AM PST on the West Coast (UTC-8).
The term “solstice” comes from the Latin word “solstitium”, meaning “the sun stands still”. Visually, the sun seems to stand still and then reverses its direction. It is interesting that the earth is actually closest to the sun in the winter, which seems contradictory – less sunlight, but closer to the sun? Yes, that is due to the earth’s 23.5° tilt and its elliptical trajectory. Likewise, the rate at which daylight hours increase or decrease depends on latitude (measurement of distance north or south of the equator, comprised of concentric rings running parallel to the equator) – in more northern latitudes there is a faster increase in daylight hours compared to slower changes in southern latitudes.
Astronomers and scientists agree that winter starts on December 21st, but meteorologists define winter as including December, January, and February – monthly definitions are easier to report than fractions of months.
If you live in the Northern Hemisphere, which is made up of half of the earth that is North of the equator where 87% of all people live, you will welcome the first day of winter on December 21st. Though we will all see the least amount of sunlight in 2021 on that day, the closer to the North Pole you are, the less light you will see. In Australia and other countries in the Southern Hemisphere, the first day of winter will occur 6 months later on June 21, 2022.
“What good is the warmth of summer, without the cold of winter to give it sweetness.” (John Steinbeck)
The Northern Hemisphere includes North America, the northern part of South America, Europe, the northern two-thirds of Africa, and most of Asia. Twelve countries can be found in both Northern and Southern hemispheres: Kiribati (an island in the central Pacific Ocean), Indonesia, Maldives, Somalia, Kenya, Uganda, Democratic Republic of Congo (formerly Zaire), Gabon (next to DCR), Sao Tome & Principe (an African island nation), Brazil, Columbia, and Ecuador. Those who live directly on the equator always have 12 hours of sunlight and 12 hours of darkness, regardless of the season; equatorial cities include Bogota, Singapore, Nairobi, and Kuala Lumpur – to name a few familiar locations.
Celebrities born on this dark day include Samuel L. Jackson, Jane Fonda, Kiefer Sutherland, Ray Romano, Phil Donahue, Wes Farrell and Josh Gibson (known as the Black Babe Ruth). They were, however, conceived 9 months prior, on March 21st, a day that was filled with much more sunlight – approximately 12 hours compared to less than 6 hours on this birth date (assuming NYC for illustrative purposes). But, then and again, who’s to complain? Above the Arctic Circle, the sun never rises on this ominous day.
Despite the darkness, some amazing events have occurred on December 21st; here’s a sampler:
- The first game of basketball was played in Springfield, MA (1891)
- Radium was discovered by Pierre and Marie Curie, paving the way for early radiography (1898)
- Josephine Baker became the first Black woman to star in a major motion picture (1934)
- Elvis Presley met President Richard Nixon (1970). A picture of this event is one of the most requested of the National Archives
- Apollo 8, the first manned Moon voyage, was launched. I wonder what the Winter Solstice looked like from their spacecraft – a Google search quickly provides a glorious answer
“Winter passes and one remembers one’s perseverance.” (Yoko Ono)
Now challenge yourself and your friends to our Winter Solstice Quiz of the Day, by downloading Quizefy from the app store if you haven’t already done so, then see how much you know and Strut Your Smart. Our Winter Solstice Quiz is only available today, then it disappears. We’ll be back again every Tuesday with a special blog posted at www.quizefy.com, along with a new trivia quiz on the same topic as the blog. Don’t forget to follow Quizefy on social media, so we can remind you of the upcoming blog and quiz content.