A ray is an idealized model of light perpendicular to its wavefronts. Light rays are straight in homogeneous media and curved in changing media. Geometrical optics describes light propagation without wave effects
Halo is produced by light interacting with ice crystals in atmosphere. Ice crystals typically form in cirrus or cirrostratus clouds (5-10 km). Crystals behave like prisms and mirrors, reflecting and refracting light
Refraction occurs when waves change direction when passing between media. Light slows down in media due to electromagnetic wave interference. Snell's law relates angles of incidence and refraction to wave speeds
Capable of burning, corroding, dissolving, or eating away by chemical action. Describes alkaline substances that burn or corrode organic material
Angle of incidence (AOI) is the range of angles for which optical components accept light. AOI is the angle between normal incidence and incident ray to component surface. Snell's Law relates refracted angle to incident angle using media indices
Lenses are transparent components used in cameras, binoculars, microscopes, and telescopes. Refraction occurs when light changes direction when entering different media. Snell's law governs light transmission through lenses