Who’s Sunset Are You Under?

7/17/05 – 7/23/05

By C. Zaitz

I had a thought one night, looking northwest out over the waters of Lake Huron. It was sunset, and the colors in the sky were glorious. I began thinking that somewhere over the Lake, or perhaps further on over there in Green Bay, Wisconsin or even in Minnesota, somewhere they were not yet seeing a sunset, because it was still day for them. For me the sky was alight with rare and shocking colors, the sun already down below the calm water. But their horizon was still bright with the sun’s light. Overhead their sky must still be blue, yet they were standing under my sunset. And what about earlier in the day? Who’s lovely sunset had I been standing under hours ago? Now their sky must be dark and starry. Who were these people? Had they (will they) see the same beauty I was now witnessing? My romantic musings led to thoughts of time zones, lines of longitude, and equations.

There are actual equations that will help answer these seemingly whimsical questions. It seems that the distance from your eye to your horizon can be figured out. The distance to the horizon is a function of your height and the radius of the earth. It turns out most people 5’-6’ tall can see about 3 miles on a clear day. But is the horizon where the sky is? No. Technically, the sky starts at our feet, but the color doesn’t. In fact, the seeing of color happens in our eyes, our brains. Uh oh- so if we aren’t there to see a sunset, is it really there at all? So how far away is our sunset? It’s closer than we think- in our heads. So I suppose the answer to my musing, “who’s sunset am I under,” would come full circle to me. I’m under my own head!

I don’t always go off on such flights of fancy, but I had some time to kill. You see, I was waiting to see Venus, and she took her sweet time showing up. Jupiter was the first planet to be seen after sunset, and Venus showed up slightly later, giving me time to ponder the sunset. The moon did sweep by both Venus and Jupiter last week, outshining them both. Now the moon grows fat and white as it reaches full moon on the 21st. By the way, the full moon always rises just as the sun sets. That’s something you can count on!

If you are out after it gets really dark, perhaps after 11pm, you will find three bright stars nearly overhead. Each star has a name and is part of a different constellation, but together we call them the Summer Triangle. It’s one of the few star groups in the sky who’s name matches its shape. The stars are named Vega, Deneb and Altair. Vega is the brightest, Altair is the most southern, and Deneb is the other one. It’s fun to find them, and if you are in dark place with little or no man-made lights invading your view, you will see a magnificent sight- the filmy light of our Milky Way Galaxy stretching through the middle of the Summer Triangle. From sunsets to galaxies- what a show.

Until next week, my friends, enjoy the view!