Monday, October 4, 2010
Science Mondays--- of light and excited electrons
I am hoping that my students will soon be able to explain how scientists have the nerve to tell us what elements are located in distant stars.
Without checking my sources... let me tell it this way.
Do you remember those energy levels that electrons like to hang out in while orbiting the nucleus, well if you hit their being with a boost of energy such as electricity or heat, an electron will grab hold of that energy and take a trip to a higher energy level. Think of a glowing rod of iron being removed from a furnace. But hey excited, while it is a hoot, doesn't tend to be a stable state for humans or electrons and the electron falls back down to a normal state of being. OK, think back to a time you felt really excited, are you now glad your heart has plummeted back to a normal state of being.
Well each element has their unique electron at the upper most level and I've been told that when electrons plummet light is emitted. Yes, excited electrons are quite busy in places like bulbs and suns and molten stuff.
So you take your handy spectroscope and check and point it at that light source and you can see the fingerprints each element has placed in the creation of light. OK, so imagine many things happen that get you excited all at once, since each is triggering you slightly differently we could see the unique aspects of each when we divide your excited self into its components.
OK, maybe this will help...
and that is how the scientists believe Green Pea Galaxies are metal-poor.
and that takes us just one Doppler effect from understanding why scientists claim we live in a not so static universe and we will be hanging out with a dude named Hubble in 1929 to get that point across.