What is this light defined as and what has it come to mean to us naturally? According to Dictionary.com 'light' is
- something that makes things visible or affords illumination: All colors depend on light.
- Physics, (A) also called luminous energy, radiant energy, electromagnetic radiation to which the organs of sight react, ranging in wavelength from about 400 to 700 nmand propagated at a speed of 186,282 mi/sec (299,972 km/sec), considered variously as a wave, corpuscular or quantum phenomenon. (B) a similar form of radiant energy that does not affect the retina, as ultraviolet or infrared rays.
- the sensation produced by stimulation of the organs of sight.
- an illuminating agent or source, as the sun, a lamp, or a beacon.
- the radiance or illumination from a particular source: the light of a candle.
Reflection- bending back; an image, representation, counterpart. The reflection of light and other forms of electromagnetic radiation occurs when the waves encounter a surface or other boundary that does not absorb the energy of the radiation and bounces the waves away from the surface.
Refraction- is responsible for image formation by lenses and the eye. It is the bending of a wave when it enters a medium where it's speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media.
Refractive indices the simplest way to define the refractive index is to say it is a dimensionless number that describes how light propagates through an optical medium (substance).
Dispersion- the refractive index of substances or materials varies with the wavelength and frequency of light; this is called dispersion. Dispersion causes prisms to divide white light into spectral colors and provides the explanation of how rainbows are formed.