by Will Thompson
First off, every science lover and stargazer is excited about August twenty-first, right? Total solar eclipses are uncommon, and when one does happen, its only visible to a select region, and only for a few minutes usually. The news is reporting that there will be interstates almost stopped up with traffic in the places the eclipse is visible, especially in the areas the point of totality will be visible (keep reading, that’s coming!) Also, restaurants, hotels, and other such businesses are going to see a huge leap in activity. So why do so many people come out to watch this phenomenon of nature? Okay, so it gets dark for a minute. So what? Well, it’s a good bit more detailed and interesting than that. So, let’s get started!
Okay, first let’s talk about what an eclipse even is. First, so there won’t be any confusion, what is the difference between a Solar and Lunar eclipse. Well, a Solar eclipse is when the moon passes in front of the sun, and for a brief period, blocks it out. If not in whole, at least in part. A Lunar Eclipse however is at night (ha-ha, lunar, night, get it?) and is caused when the earth passes in front of the moon and is in between the sun and the moon, causing the moon to be blacked out. (Chart below)
Okay, now if you looked at the chart, you probably noticed that there are a lot of freaky science terms like ‘Penumbra,’ as well as weird shaded portions of light on the diagram. First, let’s talk about the Umbra. As you may have figured out, the Umbra is the moon’s direct shadow on the earth. In other words, as the moon passes in front of the sun, the areas on earth where the moon has completely blocked out the sun is the Umbra. Likewise, the Penumbra is the area that is only partway blocked out by the sun. there are still portions still visible. Likewise, with the Lunar Eclipse. The Umbra caused by the earth completely blocks the moon from being visible. (the light from an eclipse shines through tree leaves, bottom left)
Now let’s move to earth again. How can you watch an eclipse safely? Well, probably the best method
would be to order a pair of viewing glasses. But if you can’t do that, there are ways you can make one at home. Or, you can use a ‘pinhole projector.’ Making one is probably the easiest method for viewing. You literally just take two paper plates, take a pin, nail, or other such object, poke a hole in the middle of one plate. Then, during the eclipse, hold the plate with the hole in it up to the sun. The light of the
Eclipse will literally be projected through the pinhole onto the second plate. Now, while this is certainly an effective, easy way to see an eclipse, the downside is you don’t get to see all that goes on with the actual eclipse during this time. You are instead watching a black and white projection. So, my recommendation would be the viewing glasses. Now, back to the science.
Some of the things that can be seen on the landscape around you are almost as interesting as the eclipse itself. About an hour/hour and a half before totality, when the sun is starting to be covered slowly by the moon, go find a nice, leafy tree somewhere. Now, look at the shadows being cast by it. (shown on previous page) The tree’s leaves act like hundreds of pinhole projectors, showing the progress of the moon as it slowly covers the sun. also, if you look at a flat, preferably white colored surface, you may see strange black ripples rolling across it. These are caused when the sunlight is shining through the mountain ranges on the moon as it slowly
makes its way across the sun. Also, during totality, if you look to the horizon, (if visible) the sky will be the colors of sunset and sunrise.
So that was in a nutshell but I hope you got the gist of what I was saying. Much more goes on during the eclipse than just simply darkness. It’s a fascinating and incredible experience. Hope you enjoyed reading!
by Will Thompson