How did scientists move beyond the medical ideas of Galen? Dissect the past with the 15th installment in a History of Science video series. Topics include Vesalius' dissections, the microscope, and mapping the human body.

What is life? To try to answer that question, three tools stand out as being especially useful: A book, some experiments, and the microscope! In this video, trace the history of different theories about how our body works. [12:15]

William Eberhard, of the Smithsonian Tropical Research Institute and the University of Costa Rica, and colleague Daniel Briceno film spiders in the lab, in the field and under a dissecting microscope to untangle this longstanding...