Albedo formula_5 (also called blue-sky albedo) can then be given as: Directional-hemispherical reflectance is sometimes referred to as black-sky albedo and bi-hemispherical reflectance as white-sky albedo. These terms are important because they allow the albedo to be calculated for any given illumination conditions from a knowledge of the intrinsic properties of the surface. The albedos of planets, satellites and minor planets such as asteroids can be used to infer much about their properties. The study of albedos, their dependence on wavelength, lighting angle ("phase angle"), and variation in time comprises a major part of the astronomical field of photometry. For small
To be, or not to be to make a point about "extremism in defense of liberty." P.D. James' dystopian novel "The Children of Men" (1992) refers to expected or forced mass suicides of the elderly as "Quietus". The film adaptation "Children of Men" (2006) portrays a self-administered home suicide kit, labelled "Quietus". "Star Trek"'s was named after the "Undiscovered Country" line from this soliloquy. References are made to Shakespeare during the film including Klingon translations of his works and the use of the phrase "taH pagh, taHbe' ", roughly meaning "whether to continue, or not to continue [existence]." The book (and later film) "What Dreams May