Winter Solstice: The Science of the Shortest Day of 2016!

On the winter solstice, the sun is at its southernmost point in the sky in the Northern Hemisphere.

Credit: elod pali | Shutterstock.com

Winter officially kicks off Wednesday (Dec. 21), which marks the December solstice — the day with the fewest hours of sunlight of 2016.
Although the solstice gets an entire day of recognition, it happens in an instant: at 5:44 a.m. EST (10:44 GMT), when the North Pole is at its farthest tilt of 23.5 degrees away from the sun. This position leaves the North Pole beyond the sun's reach, and plunges it into total darkness, according to EarthSky.org.
At this moment, the sun will shine directly overhead at Noon at exactly 23.5 degrees south of the equator, along the imaginary latitude line known as the Tropic of Capricorn — a line that runs through Australia, Chile, southern Brazil and northern South Africa. This is the farthest south the sun will shine the entire year, which is why the Southern Hemisphere has its longest day of the year, and the Northern Hemisphere has its shortest day of the year on the winter solstice, according to EarthSky.

At 5:44 a.m. EST, the sun will also reach its southernmost point in the sky in the Northern Hemisphere. After that moment, the sun stops moving southward and begins its trek north in the sky — and hence was given the name "solstice," which means "sun stands still" in Latin, according to NASA.
After the winter solstice, the days will begin to get longer in the Northern Hemisphere. But that doesn't mean temperatures will immediately increase. Rather, northern mid-latitudes will experience the winter chill partly because they'll only get around nine hours of daylight in the weeks following the solstice, compared with the roughly 15 hours of daily sunlight they get around the summer solstice, Live Science reported in 2012.
In addition, even as the days get longer, the oceans, which moderate temperatures on land, need a vast amount of energy from the sun to heat up.
There are countless cultures throughout time that have recognized the winter solstice. The most famous is in Stonehenge in England. When the sun sets on the shortest day of the year, the sun's rays align with Stonehenge's central Altar stone and Slaughter stone, which may have had spiritual significance to the people who built it, Live Science reported in 2013.
Across the world in Mexico's Yucatan Peninsula, the ancient stonewalled city Mayan city of Tulum also has a structure honoring the solstices. When the sun rises on the winter (and the summer) solstice, its rays shine through a small hole at the top of one of the stone buildings, which creates a starburst effect.

Original article on Live Science.

Click Here For More Articles