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O'Connell, Daniel

(Encyclopedia)O'Connell, Daniel, 1775–1847, Irish political leader. He is known as the Liberator. Admitted to the Irish bar in 1798, O'Connell built up a lucrative law practice. Gradually he became involved in th...

vacuum

(Encyclopedia)vacuum, theoretically, space without matter in it. A perfect vacuum has never been obtained; the best human-generated vacuums contain less than 100,000 gas molecules per cc, compared to about 30 billi...

Stanislaus I

(Encyclopedia)Stanislaus I, 1677–1766, king of Poland (1704–1709, 1733–35) and duke of Lorraine (1735–66). He was born Stanislaus Leszczynski. Early in the Northern War (1700–1721), Charles XII of Sweden ...

Meiji restoration

(Encyclopedia)Meiji restoration, The term refers to both the events of 1868 that led to the “restoration” of power to the emperor and the entire period of revolutionary changes that coincided with the Meiji emp...

free energy

(Encyclopedia)free energy or Gibbs free energy, quantity derived from the relationships between heat and work studied in thermodynamics and used as a measure of the relative stability of a physical or chemical syst...

Iran hostage crisis

(Encyclopedia)Iran hostage crisis, in U.S. history, events following the seizure of the American embassy in Tehran by Iranian students on Nov. 4, 1979. The overthrow of Muhammad Reza Shah Pahlevi of Iran by an Isla...

cluster munitions

(Encyclopedia)cluster munitions or cluster bombs, air-dropped or ground-launched weapons that open in mid-air and scatter dozens, hundreds, or thousands of smaller submunitions (or bomblets) over a wide area. Such ...

Safavid

(Encyclopedia)Safavid säfäˈwēd [key], Iranian dynasty (1499–1736), that established Shiite Islam in Iran as an official state religion. The Safavid state provided both the territorial and societal foundations...

radiometer

(Encyclopedia)radiometer rāˌdēŏmˈətər [key], instrument for detection or measurement of electromagnetic radiation; the term is applied in particular to devices used to measure infrared radiation. One of the ...

rayon

(Encyclopedia)rayon, synthetic fibers made from cellulose or textiles woven from such fibers; more rayon is manufactured than any other synthetic fiber. The name was adopted (1924), in preference to “artificial s...