It is easy to see that the sky is blue. Have you ever wondered why? A lot of other smart people have, too. And it took a long time to figure it out!
The light from the Sun looks white. But it is really made up of all the colors of the rainbow.
A prism is a specially shaped crystal. When white light shines through a prism, the light is separated into all its colors.
The light from the Sun looks white. But it is really made up of all the colors of the rainbow.
If you visited The Land of the Magic Windows, you learned that the light you see is just one tiny bit of all the kinds of light energy beaming around the Universe--and around you!
Like energy passing through the ocean, light energy travels in waves, too. Some light travels in short, "choppy" waves. Other light travels in long, lazy waves. Blue light waves are shorter than red light waves.
All light travels in a straight line unless something gets in the way to—
reflect it (like a mirror)
bend it (like a prism)
or scatter it (like molecules of the gases in the atmosphere)
Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. Blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere. Blue is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.
Closer to the horizon, the sky fades to a lighter blue or white. The sunlight reaching us from low in the sky has passed through even more air than the sunlight reaching us from overhead. As the sunlight has passed through all this air, the air molecules have scattered and rescattered the blue light many times in many directions. Also, the surface of Earth has reflected and scattered the light. All this scattering mixes the colors together again so we see more white and less blue.
What Makes a Red Sunset?
As the Sun gets lower in the sky, its light is passing through more of the atmosphere to reach you. Even more of the blue light is scattered, allowing the reds and yellows to pass straight through to your eyes.
I got this from http://spaceplace.nasa.gov/blue-sky/en/
We were just learning about this in science and we used this website.
The technical term is Rayleigh scattering. The amount of scattering is the inverse 4th power of light's wavelength or in less technical terms blue light is scattered a lot more than light with longer wavelengths. Rayleigh scattering is not only why the sky looks blue but also why the sun looks yellow. Since the blue rays are scattered more the sun looks yellower and more redish than it actually is. Rayleigh scattering is also why some people's eyes look blue. Eyes with little melanin get their blue color from Rayleigh scattering in the stroma of the eye. Most human albinos have blue rather than pink or red eyes.
It has been said: the sky is Blue, 'Cos God's team likes to wear that hue,
But then again it must be said: By end of day the sky is Red.
C' mon you Reds, C' mon you Reds,
Just keep your bottle, and use your heads.
For ninety minutes we'll let them know: It's Man United - here we go!
