Rainbow patterns found on a CD.

Diffraction refers to the bending of light waves around obstacles or through narrow openings. It is the reason why light appears to spread out when it passes through a small opening or around the edge of an obstacle.

Rainbow patterns found on a CD are an example of diffraction. These patterns are created when light is diffracted by the grooves on the surface of a CD.

Option 1: The blue color of the sky is not an example of diffraction. The blue color of the sky is caused by the scattering of sunlight by the Earth's atmosphere.

Option 2: The twinkling of the stars is not an example of diffraction. The twinkling of the stars is caused by the Earth's atmosphere refracting (bending) light from the stars as it passes through the atmosphere.

Option 3: The Tyndall effect is not an example of diffraction. The Tyndall effect is the scattering of light by particles suspended in a fluid or air, causing a beam of light to become visible.