Blue Sky shows why the sky is blue. This is a phenomenon called “Rayleigh scattering”. A clear tube is mounted in front of a light source with the light shining into the end of the tube. The light scattered by the tube looks blue near the projector and gets progressively yellower further down the tube. A very orange “sun” emerges from the tube and is projected onto a screen on the side of the exhibit. A polarizing filter is attached to the exhibit table so the user can experiment with the polarized properties of scattered light.