Columbia Encyclopedia

Search results

500 results found

dimension, in physics

(Encyclopedia)dimension, in physics, an expression of the character of a derived quantity in relation to fundamental quantities, without regard for its numerical value. In any system of measurement, such as the met...

electron-volt

(Encyclopedia)electron-volt, abbr. eV, unit of energy used in atomic and nuclear physics; 1 electron-volt is the energy transferred in moving a unit charge, positive or negative and equal to that charge on the elec...

Nightingale, Florence

(Encyclopedia)Nightingale, Florence, 1820–1910, English nurse, the founder of modern nursing, b. Florence, Italy. Her life was dedicated to the care of the sick and war wounded and to the promotion of her vision ...

county

(Encyclopedia)county [Fr., comté,=domain of a count], division of local government in the United States, Great Britain, and many Commonwealth countries. The county developed in England from the shire, a unit of lo...

Brenner, Sydney

(Encyclopedia)Brenner, Sydney, 1927–2019, British molecular biologist, Ph.D. Oxford, 1954. He was director of the MRC Laboratory of Molecular Biology in Cambridge, England (1979–86), and director of the MRC Mol...

Mysia

(Encyclopedia)Mysia mĭshˈēə [key], ancient region, NW Asia Minor. It was N of Lydia and its coast faced Lesbos. Mysia was not a political unit, and it passed successively to Lydia, Persia, Macedon, Syria, Perga...

Pozzuoli

(Encyclopedia)Pozzuoli pōt-tswôˈlē [key], Latin Puteoli, city (1991 pop. 75,142), Campania, S Italy, on the Gulf of Pozzuoli, an arm of the Bay of Naples. It is a port and an industrial and tourist center. Manu...

radar

(Encyclopedia)radar, system or technique for detecting the position, movement, and nature of a remote object by means of radio waves reflected from its surface. Although most radar units use microwave frequencies, ...

geologic timescale

(Encyclopedia)CE5 geologic timescale, a chronological scale of earth's history used to measure the relative or absolute age of any part of geologic time. Of the numerous timescales, the most common is based on g...

isopleth

(Encyclopedia)isopleth īˈsəplĕthˌ [key], line drawn on a map through all points of equal value of some measurable quantity. In many meteorologic, oceanographic, or geologic studies some physical or chemical pr...