BIO370Y5 Chapter 2: Microscopy
Document Summary
Light microscopes were the first microscopes invented, and they are still the most commonly used microscope. When a ray of light passes from one medium to another (ex. From air to water), refraction occurs (the ray is bent at the boundary between the two mediums) Refractive index: measure of how greatly a substance (ex. Water) slows the velocity of light: the direction and magnitude of bending are determined by the refractive indices of the two media. For example, when light passes from air into glass (which has a greater refractive index than air), light is slowed and bent towards the normal (perpendicular line to the surface) As light leaves the glass and enters the air (which is a medium with lower refractive index), light accelerates and is bent away from the normal. Thus, going into a greater refractive index medium = light slows down, and bends towards normal.
