ARECIBO, P.R. -- William E. Gordon, the father of the world's largest and most sensitive single-dish radio telescope at the Arecibo Observatory, will deliver the 40th anniversary keynote address on Nov. 1.

Gordon will present his talk, "The Arecibo Story," at 4 p.m. at the Angel Ramos Foundation Visitor and Education Center at the observatory.

The unique design of the telescope, with its 300-meter-diameter (1,000-foot) dish antenna, was based on the efforts of Gordon, beginning in 1958, when he was a professor of engineering at Cornell University, to build an instrument that would use radar to study the ionosphere, part of the Earth's upper atmosphere, and objects in the solar system. Between 1948 and 1966, Gordon conceived and supervised the design and construction of the Arecibo Observatory and directed its early.

The telescope's radar transmitters and sensitive electronic systems for picking up and analyzing weak signals have since produced a host of signiÞcant scientiÞc results, from the discovery of the first binary pulsar and conÞrmation of gravitational radiation to detection of ice on the surface of Mercury.

The National Astronomy and Ionosphere Center at Cornell University, Ithaca, N.Y., manages the Arecibo Observatory for the National Science Foundation.

Currently a consultant for Northwest Research Associates on large radar facilities and an adviser to the U.S. Air Force and Navy, Gordon served in the Air Force during World War II. He earned a Ph.D. at Cornell University in 1953, eventually joining the faculty and remaining until 1966.

At Rice University, from 1966 to 1986, he was professor of space science and electrical engineering. He also served as dean of sciences and engineering, as provost and as vice president. He is now a distinguished professor emeritus. He is a member of the National Academy of Sciences and the National Academy of Engineering and a fellow of the American Academy of Arts and Sciences, the American Association for the Advancement of Science, the American Geophysical Union and the Institute of Electrical and Electronic Engineers.