In chemistry, the term "metathesis" refers to a chemical reaction in which bonds between different atoms are broken and the atoms recombine to create a new molecule—a process that has been likened to dancers switching partners.

"Is the term 'urban ecology' an oxymoron?" asks Eric Strauss, director of the Environmental Studies Program and science director of the Urban Ecology Institute, in his lecture at the Weston Observatory. With 75 percent of the U.S. population and half of the world's population living in urban areas, the sustainability of urban ecological systems is of paramount importance, says Strauss, who suggests we must stop thinking of the city as a problem but as "a solution with respect to environmental and social challenges."

John Christian, an independent geotechnical engineer and member of the National Research Council commission investigating Hurricane Katrina and its aftermath, presents the results of his geological research on the causes of Katrina's devastating physical impact on New Orleans and the Gulf Coast. Christian also provides an overview of the work done by four other independent commissions, including the Army Corps of Engineers and researchers at the University of California, with a particular focus on why the levies of New Orleans failed.

Biologist Kenneth R. Miller recounts recent political battles over evolution, including his role as lead witness in the 2005 "intelligent design" trial in Dover, Pennsylvania, and argues against the presumption that evolution is inherently antireligious. Miller is a professor of biology at Brown University and author of Finding Darwin's God: A Scientist's Search for Common Ground Between God and Evolution (HarperCollins, 2000).

Speaker: Kenneth R. Miller

Date: May 2, 2006

Length: 1:33:15

Jonathan Balcombe, an expert in animal behavior, describes the variety of animals that seem to demonstrate pleasure, and pleasure's theoretical origins in evolution. Balcombe is an animal behavior research scientist at the Physicians Committee for Responsible Medicine in Washington, D.C., and the author of Pleasurable Kingdom: Animals and the Nature of Feeling Good (Macmillan, 2006)

Speaker: Johnathon Balcombe

Date: April 24, 2006

Length: 58:13

Astronomer Michael A'Hearn '61, principal investigator of NASA's Deep Impact Project, returns to campus as part of the "Master Class: Alumni in Residence" series. A'Hearn, also a professor of astronomy at the University of Maryland, led the team of physicists and engineers that in July 2005 intentionally collided a rocket with the comet Tempel 1, the first time humans had touched a comet in space.

A'Hearn is interviewed by Michael Naughton, a professor of physics at Boston College.

Speaker: Michael A'Hearn

Date: April 10, 2006

Length: 59:06