I saw this chart of the opacity of our atmosphere to various parts of the electromagnetic spectrum in Orion class today. (They were talking about where different kinds of telescopes could or could not be placed, if they were to be useful.)
I was interested to see the visible spectrum is in one small trench, but the really "opportunity window" is for radio waves. I did not know this.........
This version of the image is not very large -- if you like, you can click on it to see an embiggened version.
Here is the copyright data: This file is in the public domain in the United States because it was solely created by NASA. NASA copyright policy states that "NASA material is not protected by copyright unless noted".
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2 comments:
I remember reading an article years ago talking about how our eyes have evolved to work best with the wavelengths that make it through the atmosphere, and how the only other real "choice" would have been radio waves. But for structures like our eyes to work with radio waves they would have to be REALLY big, which would be incredibly hard to evolve.
Interesting!
I had never thought about any of this. Of course it's only useful to have eyes that can see with the radiation available on the surface of our planet, but I'd never thought about it..........
Yesterday they were talking about the reasons life as we know it is only possible under very specific conditions -- a star like ours, in a very particular place (not too close to the edge, not too close to the center) in a galaxy like ours....
Given everything I now know about the way we are related to every form of life on this planet (shared DNA), I am extremely dubious about all those science fiction stories I read long ago that had us landing on strange planets and able to carry on as though we'd moved to the next town. At this point, I'm betting that even if we could breathe the air, the plants native to another planet couldn't sustain us...............
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