# Physical significance of Refractive index

by mikeanndy
Tags: refractive index
 P: 3 What is the physical significance of Refractive Index(RI) ?
 PF Patron P: 10,397 Can you be more specific in your question? What exactly are you wanting to know?
PF Patron
P: 1,956
 Quote by mikeanndy What is the physical significance of Refractive Index(RI) ?
well for work I have done in petrology ( study of minerals) refractive index is very significant because dofferent minerals can be identified by they refractive indicies

just one example :)

Dave

P: 53

## Physical significance of Refractive index

The refractive index relates how quickly light travels through a given medium. It's a the number by which you divide the speed of light in a vacuum to get the speed of light in the given medium. Or, the number by which you divide the wavelength of the light in a vacuum to get the wavelength of the light the given medium.

I'd recommend looking at the Wikipedia article:

http://en.wikipedia.org/wiki/Refractive_index
 P: 747 So when the light changes medium it changes speed. If the light beam approaches the interface between media obliquely, this change of speed gives rise to refraction: a change in the direction of travel of the beam. A very simple formula (see wikipedia article on refraction) links angles of the beam to the normal in the two media to the ratio of refractive indices of the media.