The Malus' law states that the intensity of the polarized light transmitted through the analyser varies as the square of the cosine of the angle between the plane of transmission of the analyser and the plane of the polarizer.

Mathematically, it would be:

I ∞ cos2θ or I = I0 x cos2θ.

The scientific name for the crab apple tree is Malus sylvestris.

The genus is Malus, however, there are several species. By "apple" usually Malus domestica is meant.

Karl Malus was created in 1980.

Malus prunifolia was created in 1803.