Linear polarization

Any transverse wave can be polarized in the sense that it can be resolved into two mutually perpendicular components. For electromagnetic waves the polarization is of the electric vector rather than the physical movement of particles. Polaroid sun glasses allow only the vertical component of the electric vector to pass.

'Polaroids' are widely used in temperate latitudes (where the Sun is low in the sky for long periods) and the reflections of sunlight from water etc. are partly polarized with electric vector horizontal.

Note: longitudinal waves [sound waves] cannot be polarized. Light, X-rays, microwaves, etc. are transverse electromagnetic waves and are frequently polarized. 

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