Friday, May 24, 2013

shut up you stupid little birds


Sunset outside my bedroom window
Here in Alaska, the days are starting to get pretty long. I crawled into my bed last night and watched the most beautiful sunset- at about 9:45 at night. That post-sunset glow lasted until about 11:00. Then, I woke up this morning to the sound of birds chirping and the world filled with sunshine- at 5:00 AM. Starting my day off with the thought “shut UP you STUPID LITTLE BIRDS” is becoming pretty routine.


Even down south in the lower 48, there are noticeable differences in day length in the winter versus the summer. Days are longer in the summer, shorter in the winter. I used to look forward to Louisiana summer days when I could stay out waterskiing until 7:00 at night. I’d have just enough time to come in to shower and relax my tired muscles, then walk back out to the seawall to watch the sunset around 9:00. These hot summer days were very different those cold winter days of high school, walking in from school at 4:00 and it already starting to get dark outside.

So what is the deal with the changing day lengths throughout the year anyway? Why do we here in southeastern Alaska get mostly dark with a few hours of light in the winter, and vice versa in the summer? Why do the poles get 24 hours of one or the other? Why is it less noticeable as you approach the equator?

The earth is leaning. The axis around which it spins is tilted. Towards the sun, away from the sun, you ask? Well, that depends on what time of the year it is.

We earthlings make one complete trip around the sun each year. During the summer, the northern hemisphere is leaning towards the sun. By the time we’ve made it to the other side of the sun in the wintertime, the northern hemisphere is leaning away from the sun. The result of this lean is that certain parts of the globe spend a little more time in the shade than others, while others spend a little more time in the light. This is a hard thing to visualize, so let’s turn to some pictures.

Shadow zones in the winter time
In the picture above (set in our winter time), you can see that the North Pole stays in the shadow of the earth. Areas a little lower, like Alaska, skim into the light just long enough for the sun to peak over the horizon. This trend continues to weaken as you approach the equator.  The equator gets 12 hours of day every day, all year. Once you get south of the equator, then you’re spending a more and more time in the sun until you approach the South Pole. It’s summer there, getting 24 hours of light. But just wait 6 months, and the roles will have gradually reversed.

Light zones in the summer time
We’re in that role-reversal phase right now. The summer solstice, June 21, marks the northern hemisphere’s maximum “lean” towards the sun- the longest day of the year. After we get past that, the days will start getting shorter as we head back into the dreaded shadow zone. Living so far north, this time of the year drives me to embroider after work and watch Lord of the Rings, in my very own vitamin-D depraved Gollum-like transformation. By the time March rolled around this year, I was turning my nose up at taters and losing pigmentation.



Luckily, sleep masks and blackout curtains help during the summer. Socializing and reading help to resist the call of the One Ring in the winter. As they say, life is a series of tradeoffs.


I took this at noon one day in November, my precious.

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