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Science
Related: About this forumWhat Glows Green In Space?
by ELIZABETH HOWELL
While a quest for green beer in space would be difficult, were happy to report there are other ways you can celebrate Saint Patricks Day while looking at the night sky. Just check out the nebulae and aurorae in these pictures!
A word of caution, these pictures are taken by cameras that expose light for a very long time, sometimes using different filters, to bring out the colors. A nebula, for example, seen with our own eyes does not look quite as stunning.
The picture above shows the Wreath Nebula, which apparently is filled with warm dust bits that are about the same composition as smog.
Read more: http://www.universetoday.com/100455/what-glows-green-in-space/
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What Glows Green In Space? (Original Post)
n2doc
Mar 2013
OP
libodem
(19,288 posts)1. What's pink and lays under the sea...
Just kidding. That is beautiful. Ohhhh. Awwww.
pokerfan
(27,677 posts)2. Oh Be A Fine Girl/Guy...
No gree stars...
In 1964 Richard Feynman served on the State of California's Curriculum Commission and evaluated school text books...
Finally I come to a book that says, "Mathematics is used in science in many ways. We will give you an example from astronomy, which is the science of stars." I turn the page, and it says, "Red stars have a temperature of four thousand degrees, yellow stars have a temperature of five thousand degrees . . ." -- so far, so good. It continues: "Green stars have a temperature of seven thousand degrees, blue stars have a temperature of ten thousand degrees, and violet stars have a temperature of . . . (some big number)." There are no green or violet stars, but the figures for the others are roughly correct. It's vaguely right -- but already, trouble! That's the way everything was: Everything was written by somebody who didn't know what the hell he was talking about, so it was a little bit wrong, always! And how we are going to teach well by using books written by people who don't quite understand what they're talking about, I cannot understand. I don't know why, but the books are lousy; UNIVERSALLY LOUSY!
Anyway, I'm happy with this book, because it's the first example of applying arithmetic to science. I'm a bit unhappy when I read about the stars' temperatures, but I'm not very unhappy because it's more or less right -- it's just an example of error. Then comes the list of problems. It says, "John and his father go out to look at the stars. John sees two blue stars and a red star. His father sees a green star, a violet star, and two yellow stars. What is the total temperature of the stars seen by John and his father?" -- and I would explode in horror.
http://www.textbookleague.org/103feyn.htm