When light passes from a less dense to a more dense substance, (for example passing from air into water), the light is refracted (or bent) towards the normal.
The normal is a line perpendicular (forming a 90 degree angle) to the boundary between the two substances. The bending occurs because light travels more slowly in a denser medium.
A demonstration of refraction can be conducted at home in a dark room. All that is needed is a flashlight, a clear glass filled with water and a small mirror.
Answers & Comments
When light passes from a less dense to a more dense substance, (for example passing from air into water), the light is refracted (or bent) towards the normal.
The normal is a line perpendicular (forming a 90 degree angle) to the boundary between the two substances. The bending occurs because light travels more slowly in a denser medium.
A demonstration of refraction can be conducted at home in a dark room. All that is needed is a flashlight, a clear glass filled with water and a small mirror.