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physics

(Encyclopedia)physics, branch of science traditionally defined as the study of matter, energy, and the relation between them; it was called natural philosophy until the late 19th cent. and is still known by this na...

Parmenides

(Encyclopedia)Parmenides pärmĕnˈĭdēz [key], b. c.515 b.c., Greek philosopher of Elea, leading figure of the Eleatic school. Parmenides' great contribution to philosophy was the method of reasoned proof for ass...

orbit

(Encyclopedia)CE5 Important points in a planet's orbit as seen from the earth orbit, in astronomy, path in space described by a body revolving about a second body where the motion of the orbiting bodies is domi...

Barnard's star

(Encyclopedia)Barnard's star, star with the largest observed proper motion (rate of motion across the sky with respect to other stars); located in the constellation Ophiuchus. The star's large proper motion, 10.28â...

Gilbreth, Frank Bunker

(Encyclopedia)Gilbreth, Frank Bunker, 1868–1924, b. Fairfield, Me., and his wife, Lillian Moller Gilbreth, 1878–1972, b. Oakland, Calif., pioneering American industrial engineers. He was a largely self-taught e...

ephemeris time

(Encyclopedia)ephemeris time (ET), astronomical time defined by the orbital motions of the earth, moon, and planets. The earth does not rotate with uniform speed, so the solar day is an imprecise unit of time. Ephe...

viscosity

(Encyclopedia)viscosity, resistance of a fluid to flow. This resistance acts against the motion of any solid object through the fluid and also against motion of the fluid itself past stationary obstacles. Viscosity...

time , sequential arrangement of all events

(Encyclopedia)time, sequential arrangement of all events, or the interval between two events in such a sequence. The concept of time may be discussed on several different levels: physical, psychological, philosophi...

Newton, Sir Isaac

(Encyclopedia)Newton, Sir Isaac, 1642–1727, English mathematician and natural philosopher (physicist), who is considered by many the greatest scientist that ever lived. Newton was his university's representa...

Michelson, Albert Abraham

(Encyclopedia)Michelson, Albert Abraham mīˈkəlsən [key], 1852–1931, American physicist, b. Strelno, Prussia, grad. Annapolis, 1873, and studied at Berlin, Heidelberg, and Paris. He was professor of physics at...