Harold F. Weaver, pioneer of radio astronomy at UC Berkeley, dies – mySanAntonio.com

Harold F. Weaver, a pioneering UC Berkeley astronomer whose discovery of radio emissions from molecules in outer space marked the new science of radio astronomy, has died at his East Bay home in Kensington. He was 99.

Nearly 60 years ago, Professor Weaver created the universitys first radio astronomy observatory at Hat Creek, a remote valley in Plumas County 290 miles from the Berkeley campus. The surrounding mountains shielded the observatory from interference by aircraft signals and the radio noises of civilization.

Its big receiver, a dish-shaped antenna, 85 feet in diameter, would lead to major discoveries and become the mainstay of the UC Radio Astronomy Laboratory, which Professor Weaver had founded on the Berkeley campus in 1958. He would direct it for the next 15 years.

At their Hat Creek observatory, Professor Weaver and his colleagues discovered the existence of astrophysical masers the equivalent in outer space of the lasers that had been created eight years earlier by UC Berkeleys Nobel laureate physicist Charles Townes. The masers were the first evidence that objects in the gas clouds of the galaxy were emitting coherent radiation.

Professor Weaver would later discover the first interstellar molecules known as hydroxyl radicals at a time when their mysterious radio emissions were often attributed to an unknown form of space matter named mysterium. Since his discovery, many other interstellar molecules have been detected in the atmosphere of comets.

His curiosity about the universe was wide: Even as a young astronomer on the Berkeley faculty in 1953 he was using galactic star clusters and Cepheid variable stars to calculate the outer limits of the Milky Way galaxy and to estimate that the universe was at least 3.6 billion years old close to todays estimates of 4 billion years.

Ten years later, he and the late Martin Schwartzchild of Princeton University launched a giant balloon from Palestine, Texas, in a project called Stratoscope. A 2-ton telescope carried by the balloon to an altitude of 15 miles peered at Mars and discovered the worlds first evidence of water vapor in the Martian atmosphere before it crashed in a mud-filled Louisiana cow pasture.

Harold Francis Weaver was born in San Jose in 1917, and by high school he was already building his own telescopes.

Still, he debated whether he would study classics or astronomy in college. The poet Robinson Jeffers had a telescope in his Carmel home, and encouraged the young man in his telescope-building interests.

As a UC Berkeley undergraduate in the astronomy department, he met his future wife, Cecile Trumpler, the daughter of astronomer Robert Julius Trumpler, and the two were married in 1939. It was Professor Trumpler who supervised his doctoral dissertation, and the two later collaborated on a book called Statistical Astronomy, which was published in 1953 and is still in use.

During World War II, he was conscripted to work on optics research for the National Defense Research Committee and later worked on isotope separation at what was then known as the Berkeley Radiation Lab.

After the war, he served as a staff scientist at Lick Observatory and joined the astronomy faculty at UC Berkeley in 1951. He retired as a professor in 1988 after publishing more than 70 professional papers and helping to guide development of the expanding Berkeley campus as a member and chairman of the Campus Facilities Committee in the 1950s and 1960s. He helped design the astronomy departments Campbell Hall, which was recently demolished and rebuilt on the same site.

Harold was truly a giant in our department of astronomy, UC astronomy Professor Alex Filippenko said after Professor Weavers April 26 death. I will always remember his warm smile, his generosity, and how he kept going with his research and other activities well into old age.

Professor Weaver had long served as treasurer both of the American Astronomical Society and Astronomical Society of the Pacific, and was a member of the group that founded the Chabot Space and Science Center in Oakland, where he served on the board of directors for many years.

He was also interested in contemporary writing, and for many years served as treasurer and a director of the Squaw Valley Community of Writers, a summer creative writing project located near Lake Tahoe.

The Weavers have donated their longtime Kensington home to UC to be used after their deaths to fund the Trumpler-Weaver Endowed Professorship in Astronomy at UC Berkeley.

Professor Weaver is survived by his wife and three children, Margot of Tucson, Paul of Kensington and Kirk of Houston.

Memorial gifts may be made to the Cal Alumni Leadership Award in care of the California Alumni Association, 1 Alumni House, Berkeley, CA 94720.

A memorial service is being arranged.

David Perlman is The San Francisco Chronicles science editor. Email: dperlman@sfchronicle.com

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Harold F. Weaver, pioneer of radio astronomy at UC Berkeley, dies - mySanAntonio.com