(Encyclopedia) Keeling, Charles David, 1928–2005, U.S. geochemist, b. Scranton, Pa., Ph.D. Northwestern Univ., 1954. As a postdoctoral fellow at the California Institute of Technology (1953–56), he…
(Encyclopedia) Mayer, Johann TobiasMayer, Johann Tobiasyōˈhän tōbēˈäs mīˈər [key], 1723–62, German mathematician and astronomer. In 1751 he became professor of economics and mathematics at the Univ.…
(Encyclopedia) sun grebe, common name for a tropical, mainly aquatic bird of the family Heliornithidae. Sun grebes, also called finfoots, are remarkable for their colorful, puffy-toed, webbed feet,…
(Encyclopedia) Froude, WilliamFroude, Williamfr&oomacr;d [key], 1810–79, English engineer and naval architect, brother of J. Anthony Froude; educated at Oxford. In 1837 he worked on the Bristol…
(Encyclopedia) hour angle, in astronomy, a coordinate in the equatorial coordinate system. The hour angle of a celestial body is the angular distance, expressed in hours, minutes, and seconds (one…
(Encyclopedia) parsecparsecpärˈsĕc [key] [parallax + second], in astronomy, basic unit of length for measuring interstellar and intergalactic distances, equal to 206,265 times the distance from the…
(Encyclopedia) speleologyspeleologyspēlēŏlˈəjē [key], systematic exploration of caves, popularly called spelunking. It includes the measuring and mapping of caves and reporting on the flora and fauna…
(Encyclopedia) British thermal unit, abbr. Btu, unit for measuring heat quantity in the customary system of English units of measurement, equal to the amount of heat required to raise the temperature…
