First day of winter is Friday

By Riley Manning/NEMS Daily Journal

Christmas lights will come on early all over town Friday evening, as the sun makes its most brief appearance of the year, the winter solstice.
With the sun set to rise at 6:54 a.m. and set at 4:45 p.m., Friday will see only nine hours and 56 minutes of daylight.
This phenomenon is caused by the angle of the sun as it shines on the earth. As winter approaches, the angle of the earth’s light is less direct, the sun appearing at its lowest altitude above the horizon all year. It may be compared to light coming through a set of blinds versus light coming from a spotlight directly overhead.
“A solstice is actually a moment in time, rather than a whole day, when the sun’s angle stops diminishing and begins growing.” said Professor Bob Swanson, who teaches astronomy at Itawamba Community College. “On the solstice, the sun seems to stand still in the sky.”
The summer and winter solstices hold between them the summer and winter equinox, days in which the hours of daylight and darkness are equal. But Swanson said the winter solstice bears the greatest influence on Earth’s people.
“In ancient agrarian civilizations, cultures thought less daylight meant the sun was going away,” Swanson said. “That made them nervous. They needed the sun, so they held festivals to appease the gods not to take the sun away.”
For this reason, he said, many religious holidays – pagan and modern – are arranged around the solstice.
It may seem like the day with the least amount of daylight should also be the coldest day of the year, but Swanson said the weather is a step behind the sun.
“There’s a climate lag here, and it takes a while for the changes to come into effect. Seventy percent of the earth is covered in ocean. Anyone who has boiled a pot of water can see how it takes a while for that energy to make a physical change,” he said.
After the winter solstice, the sun will rise a little higher in the sky each day until the longest day in the year, the spring solstice, on June 21, 2013.
riley.manning@journalinc.com