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The darkness at hand

November 27, 2012
By DR. JAN?WOJCIK , Adirondack Daily Enterprise

In one stroke, it just got a lot darker. Standard Time returns. The sun now rises and sets one hour earlier.

That's not really true. We just make up the time of day. It's like you form your index fingers and thumbs into one of those squares photographers use to frame a potential pictures, and you move the square over to your left and say "let's now call this position of the sun as seen above the knuckles of my thumbs 2:00 in the afternoon instead of 3:00." The Adirondack Public Observatory is behind this trick.

The APO convinced the Federal Government that making it appear that dark night came an hour earlier would encourage more people to get outside after work and school and start looking at the stars.

Well, we wish the APO were that powerful, but credit for our current system actually goes to a New Zealander, George Vernon Hudson. He seriously proposed the idea in 1895, but it took until 1916 for Germany and its allies to adopt the system to conserve coal during wartime. The rest of Europe soon followed suit and the United States adopted it in 1918.

It does get dark earlier, and it's not just because of a trick. The Earth takes a yearly turn about the sun. For part of the turn, the northern hemisphere tilts towards the sun and this lets it sweep through more light during its daily turn on Earth's axis. For the part of the turn we're now on, we tilt away, and look at a lot more dark. The Earth is a lollipop with the stick sticking out a little sideways, Tupper Lake is a spot towards the top of the lollipop. Right now the stick tilts towards the sun, and Tupper Lake tilts away.

Something else is happening to our dark. If the Milky Way Galaxy was your open hand held out flat n front of you, our solar system would be on the knuckle of the pinky finger. Part of the year the people on the knuckle at night look towards the palm to the center of the galaxy. That's summer. There's lots of stars between us and the galactic center. The part we're starting now the people at night look past the fingernail beyond the hand all together. Into deep outer space. On last week's diagram, Aileen marked the Galactic Anit-center in Auriga, just north (left or above) El Nath, the tip of the Bull's horn.

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This can be good. Not only can you get outside (you think) earlier, when you look up, there are fewer and therefore more distinct stars to see. It's easier to pick up the patterns. Right now, around midnight, the dark shines with the outlines of Orion the Hunter awaiting the charge of Taurus the Bull, with Rabbit (Lepus) at his feet, and Big and Little Dogs (Canis Minor and Major) off to the side stand center stage as shown on the diagram. Use this or get a star chart on line (at, say, skymaps.com). Go outside with a flashlight. Hold up the chart so that dots on the paper replicate the pattern of the stars in the sky. Put the dots next to the stars of Orion. Then look around for the bull and the rabbit and the dogs. These stars we could say float above our galaxy's pinky finger nail with lots of black sky behind them.

Or go out even earlier and look directly overhead for a very easy constellation of stars to see. The pattern is a huge square called the Great Square of Pegasus. Pegasus is the winged horse of ancient mythology. When there were old Mobil gas stations around, the red horse with wings in the middle of the sign was Pegasus. When you look around the square overhead now, it's hard to see the legs, tail and head and even wings of the horse. You clearly see the box of the body so just stay with that. Pegasus is a horse or a constellation people once made up. You can too. Form your fingers into the photographer's square with your right hand above your left with its palm facing the stars, and hold it up in line with the square in the sky and think that looking through the finger and the star squares - you're holding in your hands a look into deep space.

Then look at the star in the square in the left lower corner, at the curve in the web of your left thumb.

That star, Alpheratz (al-FEE-ratz) has double duty. For the ancients saw it as the spot on the body of the horse just above where the left rear leg would be. And it's also a spot of the head of another pattern of stars the ancients named Andromeda, a princess they imagined swinging in the sky wearing a dress with a belt and a hem. Let's see her instead as a relaxed thumb on your right hand, hanging down and curling off at the bottom to the left. Look hard to the left of the belt, or better, to the left of the crease in your thumb behind the knuckle. See a smudge. Look through binoculars. See a fuzzy tennis ball. It's the Andromeda Galaxy, a little bigger than ours, the closest to ours, also shaped like a hand, and a hand that's moving towards our galaxy's hand to make a big clap in several billion years.

It's the closest, but it's still very far away, 2.5 billion light years. In one year a particle of light travels 6 trillion miles. Times 2.5 billion. So when we look at that smudge we're not really seeing the galaxy as it is today. But as it looked 2.5 billion years ago when the light particle passing through your hand square left home.

Now shift your hands back to cover the Great Square of Pegasus and notice that you don't notice very much of anything in that dark. On a moonless night far from outdoor lights, you may see a few stars.

But beyond our eyes' ability to see are thousands of galaxies. Though each shines with the light of hundreds of billions of stars, they are so distant that only our largest telescopes can gather enough light to see them. That's what telescopes are, actually, light funnels that squeeze the light falling on their huge mirrors down to the size of their detectors. They're the optical equivalent of the old ear horns people used before hearing aids. For the Palomar 200" telescope, the largest telescope in the world from 1948 to 1993, the 31,416 square inches of light were squeezed down to 40 square inch photographic plates, 785 times smaller than the mirror. Now, the Keck 10-meter (33 feet) telescopes on Mauna Kea in Hawaii squeeze 123,000 square inches of light down to a 3 square inch digital camera, 44,000 times smaller than the mirror. This is why we can now detect objects far fainter than we ever could before.

At the APO, we hope to obtain a telescope on the order of a meter in diameter. Small compared to Keck. But when you are able to look through such a telescope, it will squeeze the light from a circle a meter across into your pupil about 9 millimeters, 12,000 times smaller so you'll be able to see some of the galaxies lurking beyond the dark window of Pegasus.

So if you're already a member of the Adirondack Public Observatory, give yourself a pat on the back for helping our progress toward a telescope that will open the window of the Great Square. If you're not a member and meet a member, shake the member's hand. Or go further, reach into your pocket and give the APO a hand.

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Dr. Jan Wojcik is a retired literature professor at Clarkson University, director of Clarkson's Reynolds Observatory in Potsdam and a former member of the board of directors of the Adirondack Public Observatory.

 
 

 

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