(Encyclopedia) sidereal time (ST), time measured relative to the fixed stars; thus, the sidereal day is the period during which the earth completes one rotation on its axis so that some chosen star…
(Encyclopedia) short takeoff and landing aircraft (STOL), heavier-than-air craft, capable of rising from and descending to the ground with only a short length of runway, but incapable of doing so…
(Encyclopedia) Peter Damian, SaintPeter Damian, Saintdāˈmēən [key], Ital. Pietro Damiani, 1007?–1072, Italian reformer, Doctor of the Church, b. Ravenna. He became a Camaldolese monk at Fonte-…
(Encyclopedia)
CE5
Schematic representation of Kepler's second law: The areas ABF and A′B′F′ are equal and are swept out in equal intervals of time by a planet orbiting around the sun (at F).…
(Encyclopedia) dialysisdialysisdīălˈĭsĭs [key], in chemistry, transfer of solute (dissolved solids) across a semipermeable membrane. Strictly speaking, dialysis refers only to the transfer of the…
(Encyclopedia) covenantcovenantkŭvˈənənt [key], agreement entered into voluntarily by two or more parties to do or refrain from doing certain acts. In the Bible and in theology the covenant is the…
(Encyclopedia)
CE5
Chain reaction: A neutron (n) strikes the uranium nucleus (U-235), causing it to split into fission products A and B and release two neutrons. These neutrons can in turn cause…
(Encyclopedia) etching, the art of engraving with acid on metal; also the print taken from the metal plate so engraved. In hard-ground etching the plate, usually of copper or zinc, is given a thin…
(Encyclopedia) embryo screening, procedure (see genetic testing) in which a single cell is removed from an embryo two or three days after it has been conceived through in vitro fertilization and…
(Encyclopedia) spring, in geology, natural flow of water from the ground or from rocks, representing an outlet for the water that has accumulated in permeable rock strata underground. Some of the…
