History of the Scale of the Universe Debate

The Nature of the Universe Debate took place at the Smithsonian Institution National Museum of Natural History on October 4, 1998, in the Turner and Baird Auditorium. Cosmology, the study of the origin and evolution of the universe, has always fascinated humans. Over time, we have learned that the visible matter in the universe is relatively small compared to an unknown type of dark matter and that there exists a force called "dark energy" that permeates the cosmos, often referred to as a "cosmological constant."

The debate featured two leading astronomers, Turner and Peebles, who discussed their perspectives on the universe's fundamental parameters such as Hubble's Constant and Omega. Turner represented a particle cosmologist's viewpoint, while Peebles presented an astrophysical cosmologist's viewpoint. The debate concluded with a question-and-answer session and closing remarks by the moderator, Margaret Geller.

Turner and Peebles' debate marked the third event in the "Turn of the Millennium Debates" series, honoring the late David N. Schramm, a scientist who played a significant role in the very big and very small frontier between particle physics and cosmology.