Curator Hal Wallace talks about the development of the laser, an invention that has as many practical uses as portrayals in science fiction and fantasy.

Curator Steven turner discusses the work and shop of Henry Fitz, America's first commercially successful telescope manufacturer.

ʺPublic Reaction to the Transit of Venus, 1882ʺ David DeVorkin, Curator of History of Astronomy, National Air and Space Museum, Smithsonian Institution, Washington, DC