In 1998, observations of very distant exploding stars provided intriguing evidence that the expansion of the Universe is speeding up with time, rather than slowing down due to gravity as expected. Today, new and completely independent observations strongly support this amazing conclusion. Over the largest scales of space, our Universe seems to be dominated by a repulsive "dark energy," stretching the very fabric of space itself. Dr. Filippenko, who is a leader in the group that has made some of these remarkable observations, gives us a progress report on our "runaway universe" and then answers a host of audience questions about the overall behavior of the universe. Recorded October 4, 2006

Dark Energy and the Runaway Universe

Public lectures by noted astronomers on new developments in our exploration of the universe. These lectures are recorded at Foothill College near San Francisco.

Natural Sciences

Science & Medicine

Social Sciences

Medicine

In 2004, Craig Venter and Daniel Cohen suggested that if the 20th Century was the century of physics, the 21st Century will be the century of biology on our planet. Jill Tarter believes that their idea will be extended beyond the surface of our world and that we may soon have the first opportunity to study biology that developed on other worlds. She talks about her vision of the future of understanding life on Earth and beyond our planet. And she discusses projects that are underway and are planned to learn more about the possibility of intelligent life among the stars. Recorded October 11, 2017.

Will the 21st Century be the Time We Discover Life Beyond Earth?

On August 21, 2017, there will be a rare eclipse of the Sun visible throughout the U.S. and North America. Andrew Fraknoi, Foothill College, describes how eclipses work and when and where the eclipse of 2017 will be best visible. Recorded May 24, 2017.

The ‘All-American’ Eclipse of the Sun this August

By measuring the rapid orbits of the stars near the center of our galaxy, Dr. Andrea Ghez and her colleagues have moved the case for a supermassive black hole at the heart of the Milky Way from a possibility to a certainty. Recorded January 25, 2017.

The Monster Black Hole at the Center of the Milky Way Galaxy

Prof. Cominsky presents an introduction to LIGO, to gravitational waves and how they were detected, and to the kinds of black holes that “make waves.” Recorded November 2, 2016.

Space-time Symphony: Gravitational Waves from Merging Black Holes

Seth Shostak takes a look at Star Wars and other science fiction films from the point of view of a skeptical scientist, tells stories about the movies he has been asked to advise, and muses about aliens from space. Recorded October 12, 2017.

Dark Energy and the Runaway Universe

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