T he sky isn't just blue by chance. I t takes all the colors of the rainbow for us to see it that ... That's because blue and violet light have the shortest, smallest wavelengths.

Rainbows happen when sunlight passes through raindrops in the sky. When this happens, light becomes separated into a rainbow of colors—red, orange, yellow, green, blue, indigo (blue-violet), and ...

Sometimes the light runs right into one of them. In short, the sky looks blue because the blue portion of sunlight is much more likely to bounce off the molecules in the atmosphere than the ...

If there were no scattering, the sky would be dark like it is on the moon, which does not have an atmosphere. Light at the blue end of the rainbow is scattered more efficiently than the other colours.

So this is the alpine sky in a box, and Tyndall had an explanation for why this happens. He knew that white light is made of all the colours of the rainbow and he proposed that the blue light has ...