The Scale of the Universe
The Smithsonian Institution
National Museum of Natural History
21 April 1996
Debate Program: 1 - 4:30 pm; Reception: 4:30 - 5:30 pm
The Smithsonian Institution Laboratory for Astrophysics,
National Air and Space Museum;
NASA Compton Gamma Ray Observatory
Science Support Center;
George Mason University Center for Earth Observing
and Space Research;
Universities Space Research Association;
University of Maryland Department of Astronomy;
Association of Universities for Research in Astronomy;
American Astronomical Society
Robert Nemiroff, Jerry Bonnell, Jeffrey Goldstein, Sandra Barnes,
Mark Wolfire, Jodi Schoemer, Gabriela Marani, and Carolyn Weissbach
Welcome to the Scale of the Universe Debate 1996
How big is the Universe? How old? In this century observational astronomy has produced a revolution in human thought about the nature of the cosmos. This revolution was fueled by issues laid out in this very auditorium in the 1920 "Scale of the Universe" debate between Harlow Shapley and Heber Curtis. Subsequently came the discovery of an expanding Universe filled with galaxies. In this profound realization, Edwin Hubble played a major role, coining the constant that bears his name.
How big is the universe? At the root of this question now lies the Big Bang and how one converts from easily measured expansion speed to hard-to-measure distance. Hubble's constant directly facilitates this conversion, giving a scale to the Universe. There is disagreement in the astronomical community, however, over the value of the Hubble constant.
Today, Gustav Tammann and Sidney van den Bergh will champion two significantly different values of the Hubble constant in a "Scale of the Universe 1996" debate. This debate is not only about the latest results from astronomy. On display today is the nature of scientific disagreement, how scientists think, and how extremely difficult it is to understand and defeat systematic errors in scientific analysis.
Last year's astronomical debate program, also held in this historic auditorium, marked the 75th anniversary of the Curtis-Shapley debate. We are pleased to welcome you to this second in the series of the "Turn of the Millennium Astronomical Debates." We intend these public programs to highlight important problems in astrophysics that exist at the end of the second millennium. We sincerely hope that you find today's debate enjoyable, educational, and entertaining.
Robert Nemiroff NASA/GSFC/GMU
Jerry Bonnell NASA/GSFC/USRA
Jeffrey Goldstein Smithsonian/NASM
1:00 pm Introductory Lecture Pawson Welcome to the National Museum of Natural History Bonnell Welcome to the Scale of the Universe Debate Gingerich The Scale of the Universe: A Curtain Raiser in Four Acts and Four Morals (40 minutes) Trimble Ho: The Incredible Shrinking Constant 1925-1975 (40 minutes) 2:25 - 2:40 Intermission 2:40 Debate: Moderator John Bahcall Opening Argument: Sidney van den Bergh (25 minutes) Opening Argument: Gustav Tammann (25 minutes) Rebuttal: Sidney van den Bergh (15 minutes) Rebuttal: Gustav Tammann (15 minutes) Moderator: Question to Tammann (5 minutes) Moderator: Question to van den Bergh (5 minutes) Closing Statement: Gustav Tammann (5 minutes) Closing Statement: Sidney van den Bergh (5 minutes) Questions and Comments from the Open Floor (time remaining until 4:25) Closing Comment and Scientific Perspective on this Debate: Bahcall Announcements: Nemiroff 4:30 - 5:30 Reception The Associates Court
Owen Gingerich: Dr. Gingerich is a senior astronomer at the Smithsonian Astrophysical Observatory and Professor of Astronomy and the History of Science at Harvard University. He served as vice president of the American Philosophical Society as well as chairman of the US National Committee of the International Astronomical Union. In the past two decades he has become a leading authority on Kepler and Copernicus.
Virginia Trimble: Dr. Trimble is Professor of Astronomy at the University of California at Irvine and Visiting Professor at the University of Maryland in College Park. She received the 1986 National Academy of Sciences Award for scientific reviewing and currently is Editor for Comments on Astrophysics and Associate Editor for The Astrophysical Journal. She is the president of the International Astronomical Union Commission on Galaxies.
John Bahcall: Dr. Bahcall is a professor at the Institute for Advanced Study, Princeton, New Jersey, and a visiting lecturer with the rank of professor at Princeton University. Active in research across the spectrum of astrophysics, he chaired the National Academy of Sciences and National Research Council's committee to survey and prioritize the most important programs in astronomy and astrophysics in the 1990s.
Sidney van den Bergh: Dr. van den Bergh is a senior scientist and former director of the Dominion Astrophysical Observatory as well as adjunct professor of the University of Victoria, Canada. With over 500 publications, his research interests include stellar populations, supernovae and their remnants, the extragalactic distance scale and cosmology. He is a recipient of the Canadian National Research Council's Order of Canada.
Gustav Tammann: Dr. Tammann is director of the Astronomical Institute of the University of Basel, Switzerland, European Space Agency Member of the Space Telescope Advisory Team and Member of Council of the European Southern Observatory. His research interests include supernovae and the extragalactic distance scale. Professor Tammann is a former President of the International Astronomical Union Commission on Galaxies.