Rayleigh Scattering: Why does the sky look blue?

When light from the sun hits the Earth's atmosphere, the shorter wavelength blue light gets scattered in all directions at the same time. This is why the sky appears to be blue. The intensity of blueness is greater directly overhead compared with the blueness closer to the sunlight. "Rayleigh scattering - named after the British physicist Lord Rayleigh - in the atmosphere causes diffuse sky radiation, which is the reason for the blue colour of the sky and the yellow tone of the sun itself." (Wikipedia). When doing this experiment, some students may see blue in their glass while others may see grey or white. The students should look at the glass at an angle and look toward the bottom third of the glass. Have students look aroundat their classmates' glasses, while staying at their own desks. The blueness is easier to see from a distance.