See under .
two stars that appear as one if not viewed through a telescope with adequate magnification, such as two stars that are separated by a great distance but are nearly in line with each other and an observer (optical double star) or those that are relatively close together and comprise a single physical system (physical double star)
two stars, appearing close together when viewed through a telescope; either physically associated (binary star) or not associated (optical double star) See also binary star, optical double star
two stars that appear close together when viewed through a telescope but are not physically associated and are often separated by a great distance Compare binary star
See binary star.
plural noun, Movies, Television. 1. special visual effects, as the wipe or dissolve, created in the camera or especially in a film laboratory by technicians using complex optical and electronic equipment.
noun 1. a very thin, flexible glass or plastic strand along which large quantities of information can be transmitted in the form of light pulses: used in telecommunications, medicine, and other fields. optical fiber A flexible transparent fiber of extremely pure glass or plastic, generally between 10 and 200 micrometers in diameter, used especially to […]
- Optical fibre
noun 1. a communications cable consisting of a thin glass fibre in a protective sheath. Light transmitted along the fibre may be modulated with vision, sound, or data signals See also fibre optics communications (fibre optics, FO, US “fiber”, light pipe) A plastic or glass (silicon dioxide) fibre no thicker than a human hair used […]
- Optical flint
noun 1. an optical glass of high dispersion and high refractive index containing lead oxide. They are used in the manufacture of lenses, artificial gems, and cut glass Also called flint glass