(Encyclopedia) meter, abbr. m, fundamental unit of length in the metric system. The meter was originally defined as 1/10,000,000 of the distance between the equator and either pole; however, the…
(Encyclopedia) rocketsonde, rocket with instrumentation capable of measuring and transmitting meteorological data to altitudes of 250,000 ft (76,200 m). See radiosonde.
(Encyclopedia) Lambert, Johann HeinrichLambert, Johann Heinrichyōˈhän hīnˈrĭkh lämˈbĕrt [key], 1728–77, German-French philosopher and scientist, b. Alsace. He developed many basic concepts in…
(Encyclopedia) joulejoulej&oomacr;l, joul [key], abbr. J, unit of work or energy in the mks system of units, which is based on the metric system; it is the work done or energy expended by a force…
(Encyclopedia) measurement, determination of the magnitude of a quantity by comparison with a standard for that quantity. Quantities frequently measured include time, length, area, volume, pressure,…
(Encyclopedia) ampereampereămˈpēr [key], abbr. amp or A, basic unit of electric current. It is the fundamental electrical unit used with the mks system of units of the metric system. The ampere is…
(Encyclopedia) note, in musical notation, symbol placed on or between the lines of a staff to indicate the pitch and the relative duration of the tone to be produced by voice or instrument. The…
(Encyclopedia) centimetercentimetersĕnˈtĭmēˌtər [key], abbr. cm, unit of length equal to 0.01 meter, the basic unit of length in the metric system. The centimeter is the unit of length in the cgs…
Recent Discoveries: Did Cosmic Dust Doom the Dinosaurs? A controversial study by researchers at the University of Florida and Carnegie Institution theorizes that space dust in Earth's…
(Encyclopedia) Gregory, James, 1638–75, Scottish mathematician. He invented a reflecting telescope (1661), which he described in his Optica promota (1663). In 1668 he became professor of mathematics…