|a chattering or flighty, light-headed person.|
|an extraordinary or unusual thing, person, or event; an exceptional example or instance.|
|1.||the smallest possible angle of incidence for which light rays are totally reflected at an interface between substances of different refractive index|
|2.||another name for stalling angle|
|critical angle (krĭt'ĭ-kəl) Pronunciation Key
The smallest angle of incidence at which radiation, such as light, is completely reflected from the boundary between two media. At angles smaller than the critical angle, some of the radiation enters the second material and is refracted.