Jonathan Swinchatt, a geologist by training, writes and produces educational video programs about earth and earth science; he is the author of "The Foundations of Wine in the Napa Valley: Geology, Landscape, and Climate.". David G. Howell is a research geologist with the U.S. Geological Survey in Menlo Park, California, and author of "Principles of Terrane Analysis "(second edition, 1995). Together they produced the video "EarthNectar, "which explores relationships between earth and wine in the Napa Valley.