The Sky is Blue: A Fact-Checked Truth

Gases and particles in Earth's atmosphere scatter sunlight in all directions. Blue light 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.

Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. Blue light is scattered more than the other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.

When light bumps into them, some of the light gets reflected, or bounces off the molecule, while the rest of the energy is absorbed by the molecule. While all colors are scattered by air molecules, violet and blue are scattered most. The sky looks blue, not violet, because our eyes are more ...

The sky appears blue because of a phenomenon called Rayleigh scattering. Sunlight, although it looks white, is actually made up of many colours, each with a different wavelength. At one end of the spectrum is red light which has the longest wavelength and at the other are blue and violet light which have a much shorter wavelength.

The blue color of the sky is caused by the scattering of sunlight off the molecules of the atmosphere. This scattering, called Rayleigh scattering, is more effective at short wavelengths (the blue end of the visible spectrum). Therefore the light scattered down to the earth at a large angle ...

Rayleigh scattering refers to the scattering of light by small gas molecules, with shorter wavelengths (blue light) being scattered more effectively than longer wavelengths (red light).

The U.S. Supreme Court in Hall v. Geiger Jones Co., 242 U.S. 539 (1917), described the targeted activity as “speculative schemes which have no more basis than so many feet of ‘blue sky.’' Blue sky laws developed in the years leading up to the Great Depression in response to ordinary investors losing money in highly speculative or fraudulent schemes promising high investment returns, such as oil fields and exotic investments in foreign countries.

Second, despite how obvious it is that "sky" refers to the atmosphere, and not the objects or space beyond it (search Google for "sky and space difference" and the top dozen or so hits agree), there are numerous references (such as the Sky article) making the opposite claim. Which happens to go hand-in-hand with the article's message that certain "obvious" statements, such as "you can't see the sky at night", are less obvious than they appear if they presume a standard definition of a word that actually has multiple meanings. Certainly for purposes of this article, it seems odd to consider the color of anything other than the atmosphere, since it's clearly the atmosphere that's blue, not anything else.

People who think that there is something wrong with the world sometimes point to the sky and say it's different. It was bluer a decade ago, and certainly bluer when they were children. Was it bluer? Probably not. Probably what they have is simply a memory of bluer skies, a memory that natuarally gets more intense with age, because that's what memories of color do.