My mind turns to June and July and sitting on rocks above a lake watching the sunset, or gathering around a campfire while the sun still lingers above the distant mountains or even rising with the bugle and jumping into the lake, the sun well above the horizon. Today marks the turning point towards those long camp days.
I am so enamored of the winter solstice that I eagerly check the sunrise and sunset times to confirm that the days will indeed be lengthening come tomorrow. This isn’t as straightforward as it sounds. Math is actually required, albeit simple arithmetic. Unless I visit one of the websites that list the length of day down to the second, removing the need for any calculation at all.
The sun actually began setting later on December 15 in Boston, but sunrise also continues to occur later right on until January 6. Curiously I wonder if that has anything to do with the 12 days of Christmas, but I digress. So how is it that we experience a longer day (here in the northern hemisphere) even as sunrise continues to occur later?
Because the earth’s orbit around the sun is an ellipse and the earth is closest to the sun near the winter solstice, the earth is actually traveling faster in its orbit now than in June. So if you feel like you’re flying faster this time of year, well you are, astronomically speaking. During a single day’s revolution, the earth travels a greater distance along its orbit this time of year than it does during our summer.
Consider that you are standing on the earth, facing directly toward the sun at point A. The earth rotates through one day and simultaneously moves along its elliptical orbit. Consequently point A after one day isn’t quite facing directly toward the sun. The earth needs to rotate a tiny bit more for A to be facing the sun again. This corresponds to the sun rising just a bit later. And at the other end of the day, the sun is still in view and the earth needs to rotate a tiny bit more before sunset is experienced. This corresponds to the sun setting just a bit later.
Tomorrow sunrise will be a bit later than today, but sunset will be later by a smidgeon more and voila, tomorrow we will have daylight for nearly a second more than today.
Tomorrow I will relish that second. As I feel myself being flung faster past the sun at greater speeds this time of year, I can look forward to slowing down during the long days of summer camp.
Finally! A description of the lengthening days that makes sense! Thank you!
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