[CUA Office of Public Affairs]

March 25, 2002



Astronomer to Speak on Accelerating Expansion of the Universe


Astronomer Alex Filippenko, a prominent member of an international team studying the expansion of the universe, will speak in early April at The Catholic University of America.


Filippenko, a popular UC Berkeley professor who has appeared in several TV documentaries about the universe, will deliver the 21st annual Karl Herzfeld Memorial Lecture at 4 p.m. on Thursday, April 4, in Herzfeld Auditorium at Hannan Hall.


His talk, entitled “Einstein’s Biggest Blunder? The Case for Cosmic Antigravity,” will focus on research involving distant exploding stars called supernovae and a curious repulsive force in the universe first suggested by Albert Einstein. The research led Filippenko’s team and another independent group of scientists to theorize that the expansion of the universe is speeding up rather than slowing down as scientists had expected.


Fred Bruhweiler, director of Catholic University’s Institute for Astrophysics and Computational Sciences, describes Filippenko as “a latter day Carl Sagan,” a reference to the late astronomer and gifted storyteller who explored the mysteries of the universe in lectures, books and the PBS series “Cosmos.”


“Filippenko is very energetic and well-organized when he speaks,” says Steve Kraemer, an associate professor of physics at Catholic University. “He can make the subject extremely accessible and interesting without sacrificing content.”


The findings by Filippenko and others, which Science magazine dubbed the Science Breakthrough of 1998, threw the scientific world into a tailspin and reinstated Albert Einstein’s idea of a cosmological constant, a repulsive force that he believed countered the effect of gravity to maintain what he said was a static universe.


Einstein had abandoned the cosmological constant, calling it the worst “blunder” of his career, after astronomer Edwin Hubble discovered in 1929 that the universe is actually expanding. Hubble’s discovery led cosmologists to assume that the universe began in an expanding state with the Big Bang and that gravity gradually has slowed down the expansion.


But Filippenko and other researchers found compelling evidence that the universe’s expansion is accelerating with time. They based their findings on Hubble Space Telescope observations of supernovae, very bright exploding stars used as markers for measuring huge distances in space. To explain their findings, the scientists resurrected Einstein’s cosmological constant, saying it was a positive force countering the effect of gravity and driving the continued expansion of the universe rather than stunting its growth. It seems that Einstein was right but for the wrong reason.


An observational astronomer who makes frequent use of the Hubble telescope and the Keck 10-meter telescopes, Filippenko’s primary areas of research are supernovae, active galaxies, black holes and cosmology. The recipient of several major science awards, he also has won top teaching awards at UC Berkeley.

Filippenko’s talk is sponsored by the Catholic University Department of Physics, which established the lecture series in memory of Viennese-born scholar Karl Herzfeld, who became department chair in 1936 and served for 25 years.


Other Herzfeld lecturers have included renowned physicist Freeman Dyson, best known for his work on the possibility of extraterrestrial civilizations, and several Nobel laureates, including chemist Jerome Karle and the late physicist Arthur Schawlow.


Filippenko will speak for about an hour and then take questions. The lecture is free and open to the public. A reception will follow.


For additional information, contact Chris Harrison or Catherine Lee at 202-319-5600.





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Revised: Feb. 18, 2002

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The Catholic University of America,
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