ABSTRACT
Light is simply one form of electromagnetic radiation, which also includes x-rays, radio and television signals, infrared radiation and cosmic rays. The visible light perceived by our eyes has a wavelength that ranges from 700 nanometers (the very red end of the spectrum) to about 400 nanometers (the violet end of the spectrum). A nanometer is one-billionth of a meter. Interestingly, visible light has a higher frequency than radar or radio waves, but a lower frequency than x-rays.
