Radar sets broadcast radio waves, usually between 100 and 10, 000 megacycles, pick up the portion reflected back by objects, and ... In long-distance telephone lines electric waves traveling through the wires echo a speakera#39;s own conversation back to him, and must be .... The moon moves along at c.2, 000 mi. an hour and the earth is rotating in the same direction. ... ECOLOGY From arctic tundra to tropical savanna, from the thin Cross references are indicated by SMALL CAPITALS.
|Title||:||The Columbia Encyclopedia|