Sunday, December 21, 2014

How We Experience the Winter Solstice

Today at 5:03 am CST is the winter solstice.  It's the time when if you where somewhere along the Tropic of Capricorn, the sun would be directly overhead; or as my wife Sara taught her students this week, the perpendicular rays of the sun fall on you.  The Tropic of Capricorn is as far south as the sun will ever appear directly overhead.  This is a bit abstract for many of us.  We'll experience the winter solstice in the following ways in the northern hemisphere, and more specifically in Minnesota:

  • it's the shortest day of the year.  For us in Minnesota, we'll have 8 hours and 46 minutes of daylight.
  • the sun is at lowest point it'll reach in the sky at "noon".
  • the sun rises and sets the farthest to the south.
Then starting tomorrow, the sun slowly starts to climb higher in to the sky, and the days slowly get longer.  The sun also starts to rise closer to due east each day and sets closer to due west each day, as we approach the spring equinox in March.

Of course this is a relative description of what is happening, the earth is the one doing the moving compared to the sun; all these changes are due to the tilt of the earth, and the change of this tilt relative to the sun as it travels around the sun.

I hope you enjoy the solstice!

(note: no attempts at historical accuracy were made in the above depictions of holidays associated with the solstice)