(Encyclopedia) atomic clock, electric or electronic timekeeping device that is controlled by atomic or molecular oscillations. A timekeeping device must contain or be connected to some apparatus that…
(Encyclopedia) sea level, the level of the sea, which serves as the datum used for measurement of land elevations and ocean depths. Theoretically, one would expect sea level to be a fixed and…
(Encyclopedia) pendulum, a mass, called a bob, suspended from a fixed point so that it can swing in an arc determined by its momentum and the force of gravity. The length of a pendulum is the…
(Encyclopedia)
CE5
A pendulum clock: Weight-driven clock mechanism
clock, instrument for measuring and indicating time. Predecessors of the clock were the sundial, the hourglass, and the…
(Encyclopedia) obscenity, in law, anything that tends to corrupt public morals by its indecency. The moral concepts that the term connotes vary from time to time and from place to place. In the…
(Encyclopedia) megatheriummegatheriummĕgəthērˈēəm [key] [Gr.,=large beast], extinct ground sloth, of the genus Megatherium, that was widely distributed in North and South America in the Pleistocene…
(Encyclopedia) Ratas, Jüri, 1978–, Estonian political leader. A member of the Center party, a populist party with strong support among ethnic Russians, Ratas was mayor of Talinn (2005–7), before…
(Encyclopedia) Robinson, Sugar Ray, 1920–89, American boxer, b. Detroit as Walker Smith, Jr. He began boxing after three years of high school in New York City. Having won all his amateur fights (…
(Encyclopedia) Chamberlin, Guy (Berlin Guy “Champ” Chamberlin), 1894–1967, American football coach and player, b. Blue Springs, Neb., grad. Univ. of Nebraska, 1916. Chamberlin was one of the greatest…
(Encyclopedia) Djokovic, Novak, 1987–, Serbian tennis player, b. Belgrade. He began winning European championships at age 14, and played in his first Grand Slam tournament, the Australian Open, in…
