Robert L. Wolke is professor emeritus of chemistry at the University of Pittsburgh and researcher in both chemistry and physics. As an educator and lecturer, he enjoys a national reputation for his ability to make science understandable and enjoyable. He is the author of What Einstein Didn't Know: Scientific Answers to Everyday Questions; Impact: Science on Society; and Chemistry Explained, as well as dozens of scientific research papers. His bi-weekly column, "Food 101," in which he answers scientific questions about food, appears in The Washington Post. He lives in Pittsburgh.