SANTA CRUZ, CA–About 200 astronomers, including many of the world’s leading astrophysicists and cosmologists, will gather from August 8 to 12 at the University of California, Santa Cruz, for a conference to honor three UCSC professors–astronomers George Blumenthal and Sandra Faber and physicist Joel Primack.

Blumenthal, Faber, and Primack have made fundamental contributions to the scientific understanding of how galaxies formed and how the universe has evolved over time. The conference in their honor, organized to celebrate their 60th birthdays, will address the recent explosion of observational data in astronomy and explore its theoretical implications.

The title of the conference, “Nearly Normal Galaxies in a Lambda CDM Universe,” refers to the prevailing Cold Dark Matter (CDM) theory of cosmology. Convincing evidence for dark matter, which cannot be seen but can be detected indirectly by observing its gravitational effects, was discovered by astronomers in the late 1970s. About 85 percent of all the matter in the universe is estimated to be dark matter, while ordinary matter accounts for the remaining 15 percent. In the 1980s, Blumenthal, Faber, Primack, and others established the important role of slow-moving (“cold”) dark matter in the formation, properties, and evolution of galaxies. Their ideas about CDM, though more than 20 years old, remain the dominant working paradigm for structure formation in the universe.

The Greek letter lamda in the title refers to a repulsive force that Albert Einstein added to his 1916 theory of gravity to counteract the attractive force of gravity so as to preserve a static universe. Einstein called lambda his “biggest blunder” after the astronomer Edwin Hubble discovered in 1929 that the universe was not static but expanding. Recent observations, however, show that the expansion of the universe is not being slowed by gravity, as expected, but is actually speeding up. This surprising result suggests that Einstein may have been right after all about the repulsive force, lambda, which is now called “dark energy.”

The conference title also refers back to a landmark conference held at UCSC in 1986 and documented in a book edited by Faber, Nearly Normal Galaxies (Springer-Verlag, New York, 1987). This year’s conference is expected to be equally memorable as one of the major conferences of the decade on galaxy formation.

“Progress in cosmology has been truly astronomical since the last conference 19 years ago,” said David Koo, a professor of astronomy and astrophysics at UCSC who is helping to organize this year’s conference.

“Using the Hubble Space Telescope and Keck Telescopes finished in the mid-1990s, astronomers can now peer at ‘nearly normal’ galaxies 8 billion years further back in time than the 4 billion years possible in 1986, to near the beginning of our universe just after the Big Bang,” Koo said.

Blumenthal, a professor of astronomy and astrophysics, joined the UCSC faculty in 1972. He continues to investigate the origin of structure in the universe, such as galaxies and clusters of galaxies, and the role that dark matter plays in the formation and evolution of this structure. He also studies related cosmological issues, such as the generation of density fluctuations during an early inflationary phase of the universe. In addition to his work in cosmology, Blumenthal has studied gamma-ray bursts, accretion disks, and active galactic nuclei and maintains a strong interest in those areas. He has served as chair of the UC Academic Senate for 2004-05.

Faber, a University Professor of astronomy and astrophysics, also came to UCSC in 1972. She is a leading authority on telescopes and astronomical instrumentation, and is renowned for her work on the role of dark matter in the formation of structure in the universe. Faber and a group of colleagues were the first to detect high-speed flows of galaxies on cosmic scales. She is currently involved in several projects, including a major survey of distant galaxies (the DEEP Survey), studies of supermassive black holes in the centers of galaxies, and the development of adaptive optics systems to sharpen the images of ground-based telescopes. Her many awards and honors include the Bok Prize of Harvard University, the Dannie Heineman Prize for Astrophysics, and election to the National Academy of Sciences, the American Academy of Arts and Sciences, and the American Philosophical Society.

Primack, a professor of physics, has done pioneering research in particle physics and cosmology. His current research in cosmology involves the use of supercomputers to simulate and visualize the evolution of the universe and the formation of galaxies. These computer simulations enable him and his collaborators to compare the predictions of theories with the observational data. Primack is also active in addressing policy issues in science and technology, and he currently chairs the American Physical Society Forum on Physics and Society. His most recent policy work has been on efforts to protect the near-Earth space environment and on NASA funding for astrophysics. A fellow of the American Physical Society and the American Association for the Advancement of Science, Primack joined the UCSC faculty in 1973.

As part of the conference, Primack and his wife, Nancy Abrams, will give a public talk entitled “The View from the Center of the Universe: Discovering Our Extraordinary Place in the Cosmos.” The talk will be based on their new book by the same title, due to be published later this year. Primack and Abrams, a writer and songwriter, have a special interest in the cultural implications of modern cosmology and have cotaught a course on cosmology and culture at UCSC since 1996. Their presentation will take place from 8 to 10 p.m. on Tuesday, August 9, in Classroom Unit 2 on the UCSC campus. The event is free and open to the public. For additional information about the public lecture, contact Nancy Moore at (831) 459-5092 or nmoore@ucsc.edu.

The conference is sponsored by NASA, the National Science Foundation, and Orion Telescopes & Binoculars. Additional details about the conference are available online at http://astro.ucsc.edu/~nng/.