vary with time
81fluid mechanics — an applied science dealing with the basic principles of gaseous and liquid matter. Cf. fluid dynamics. [1940 45] * * * Study of the effects of forces and energy on liquids and gases. One branch of the field, hydrostatics, deals with fluids at… …
82hydrosphere — /huy dreuh sfear /, n. the water on or surrounding the surface of the globe, including the water of the oceans and the water in the atmosphere. [1885 90; HYDRO 1 + SPHERE] * * * Discontinuous layer of water at or near the Earth s surface. It… …
83metamorphic rock — Any of a class of rocks that result from the alteration of preexisting rocks in response to changing geological conditions, including variations in temperature, pressure, and mechanical stress. The preexisting rocks may be igneous, sedimentary,… …
84Water quality — A rosette sampler is used to collect samples in deep water, such as the Great Lakes or oceans, for water quality testing. Water quality is the physical, chemical and biological characteristics of water.[1] It is a measure of the condition of… …
85marine ecosystem — Introduction complex of living organisms in the ocean environment. Marine waters cover two thirds of the surface of the Earth. In some places the ocean is deeper than Mount Everest is high; for example, the Mariana Trench and the… …
86geochronology — geochronologic /jee oh kron l oj ik/, geochronological, adj. geochronologist, n. /jee oh kreuh nol euh jee/, n. the chronology of the earth, as based on both absolute and relative methods of age determination. [1890 95; GEO + CHRONOLOGY] * * *… …
87Universe — For other uses, see Universe (disambiguation). Physical cosmology …
88Full moon cycle — The full moon cycle is a cycle of about 14 lunations over which full moons vary in apparent size and age (time since new moon). The sequence is *Full moon big (perigee at full moon) *Full moon young (perigee at first quarter) *Full moon small… …
89Physical oceanography — World ocean bathymetry. Physical oceanography is the study of physical conditions and physical processes within the ocean, especially the motions and physical properties of ocean waters. Physical oceanography is one of several sub domains into… …
90Orbital mechanics — A satellite orbiting the earth has a tangential velocity and an inward acceleration. Orbital mechanics or astrodynamics is the application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other… …
