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blackbody

(Encyclopedia)blackbody, in physics, an ideal black substance that absorbs all and reflects none of the radiant energy falling on it. Lampblack, or powdered carbon, which reflects less than 2% of the radiation fall...

nucleus, in physics

(Encyclopedia)nucleus, in physics, the extremely dense central core of an atom. Following the discovery of radioactivity by A. H. Becquerel in 1896, Ernest Rutherford identified two types of radiation given off b...

MacMahon, Marie Edmé Patrice de

(Encyclopedia)MacMahon, Marie Edmé Patrice de märēˈ ĕdmāˈ pätrēsˈ də mäkmäōNˈ [key], 1808–93, president of the French republic (1873–79), marshal of France. MacMahon, of Irish descent, fought in ...

Tillich, Paul Johannes

(Encyclopedia)Tillich, Paul Johannes tĭlˈĭk [key], 1886–1965, American philosopher and theologian, b. Germany, educated at the universities of Berlin, Tübingen, Halle, and Breslau. In 1912 he was ordained a m...

Clark, Ramsey

(Encyclopedia)Clark, William Ramsey, 1927–2021, attorney general of the United States (1967–69), b. Dallas, Tex., Univ. of Texas-Austin (BA, 1949), Univ. of Chica...

genocide

(Encyclopedia)genocide, in international law, the intentional and systematic destruction, wholly or in part, by a government of a national, racial, religious, or ethnic group. Although the term genocide was first c...

Ghose, Aurobindo

(Encyclopedia)Ghose, Aurobindo ôrōbĭnˈdō gōsh [key], 1872–1950, Indian nationalist leader and mystic philosopher. Born in Bengal, he was sent to England and lived there for 14 years, completing his educatio...

Baldwin, Robert

(Encyclopedia)Baldwin, Robert, 1804–58, Canadian statesman, leader of the movement for representative government in Canada, b. York (now Toronto), Ont. His father, William Warren Baldwin (1775–1844), was a lead...

hygrometer

(Encyclopedia)hygrometer hīgrŏmˈətər [key], instrument used to measure the moisture content of a gas, as in determining the relative humidity of air. The temperature at which dew or frost forms is a measure of...

Story, Joseph

(Encyclopedia)Story, Joseph, 1779–1845, American jurist, associate justice of the Supreme Court (1811–45), b. Marblehead, Mass. Admitted to the Massachusetts bar in 1801, he practiced law in Salem and was sever...