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digital radio

(Encyclopedia)digital radio, audio broadcasting in which an analog audio signal is converted into a digital signal before being transmitted; also known as digital audio broadcasting (DAB) and high-definition radio....

Alpha Centauri

(Encyclopedia)Alpha Centauri ălˈfə sĕntôrˈē [key], brightest star in the constellation Centaurus and 3d-brightest star in the sky; also known as Rigil Kent or Rigil Kentaurus; 1992 position R.A. 14h39.1m, De...

federal government

(Encyclopedia)federal government or federation, government of a union of states in which sovereignty is divided between a central authority and component state authorities. A federation differs from a confederation...

satellite, artificial

(Encyclopedia)CE5 A. Nimbus weather satellite B. Syncom communications satellite satellite, artificial, object constructed by humans and placed in orbit around the earth or other celestial body (see also space ...

Sperry, Elmer Ambrose

(Encyclopedia)Sperry, Elmer Ambrose, 1860–1930, American inventor, b. Cortland, N.Y. Although probably best known for his work on the gyroscope, he also invented the gyrocompass (1910), an extremely effective hig...

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, ...

Meurthe

(Encyclopedia)Meurthe mört [key], river, c.105 mi (169 km) long, rising in the Vosges, NE France, and flowing NW past Lunéville to join the Moselle River just N of Nancy. Its very irregular level has necessitated...

Msta

(Encyclopedia)Msta əmstäˈ [key], river, c.280 mi (450 km) long, rising N of Vyshne Volochek, NW European Russia, and flowing generally NW into Lake Ilmen near Novgorod. Navigable in its lower course, it is inclu...

Hamitic languages

(Encyclopedia)Hamitic languages, subfamily of the Hamito-Semitic family of languages, a now-abandoned system of classification for languages of N Africa and SW Asia. The Egyptian, Berber, Cushitic, and (sometimes) ...

American Samoa, The National Park of

(Encyclopedia)American Samoa, The National Park of, c.9,000 acres (3,645 hectares), American Samoa, S Pacific Ocean. Comprising areas on the islands of Ofu, Ta'u, and Tutuila, the park features the only paleotropic...