Light

Go back to WAVES page

If a beam of light passes through a narrow slit (close to the wavelength of light around 500nm), it will spread out[diffract]. Waves only interfere if they have to same frequency and similar amplitude.
 * Light reflects and refracts, and then it also interferes and diffracts**.

When light passes through polaroid, it becomes polarized in one direction.
 * Polarization**



Light is an electromagnetic wave; that is a propagation of transverse disturbance in an electric and magnetic field. White light is made up all colours mixed together. The wavelength of light can vary from 400nm to 800nm. If it is passed through a prism, the each wavelength refracts by a different amount and therefore a different angle.
 * EM spectrum**
 * EM waves can travel through a vacuum.**
 * The full range of wavelength is from 10 -14 m to 10 4 m.**

Electromagnetic spectrum

[|LINK TO NASA WEBSITE ABOUT EM SPECTRUM]

The amplitude of light is related to its brightness.
 * The intensity of light is proportional to the square of the amplitude.**


 * The speed of EM waves in a vacuum is 2.99 x 10 8 ms -1 .**