Fred Schaefer of the University of the Sciences, conducts an explosion experiment with liquid carbon dioxide at Earth, Bread and Brewery in Mount Airy, Philadelphia. Tonight's experiments were part of the 10 day Philadelphia Science Festival  and here he was assisted by Faye Flam, who writes about evolution in her "Planet of the Apes" column in the Philadelphia Inquirer. Schaefer holds "tabletop science" evenings once a month at the restaurant! Watch video here.