James Trefil has authored or coauthored numerous books on science for the general audience. His interest in scientific literacy began with a contributed essay to E. D. Hirsch's Cultural Literacy and Science Education Standards. He serves as a regular contributor and science consultant for Smithsonian Magazine and as a science commentator on National Public Radio. He received undergraduate degrees from the University of Illinois and Oxford University. After receiving a doctorate in theoretical physics from Stanford University, he help post-doctorate and faculty appointments in Europe and the United States. James Trefil is the Clarence Robinson Professor of Physics at George Mason University. He has made contributions to research in elementary particle physics, fluid mechanics, medical physics (including cancer research), and the earth sciences, Trefil was recently awarded the prestigious Gemant Prize of the American Institute of Physics for his efforts to present science to the public. Robert M. Hazen is the Clarence Robinson Professor of Earth Science at George Mason University and Staff Scientist at the Carnegie Institution of Washington's Geophysical Laboratory. Hazen developed a fascination for rocks and minerals as a child growing up in mineral-rich Northern New Jersey, and he pursued that interest as an undergraduate at the Massachusetts Institute of Technology. After receiving a doctorate in earth sciences from Harvard University, he spent a year at Cambridge University as a NATO Postdoctoral Fellow. In addition to teaching courses on scientific literacy, scientific ethics, symmetry in art and science, and visual thinking, he performs research on materials at high pressure. His current studies on the origin of life explore the hypothesis that life arose in a deep, high-pressure environment. Hazen is active in presenting science to the public. He developed a 60-lecture video version of this textbook, Great Principles of Science, which is available nationally through The Teaching Company. Hr has appeared on numerous radio and television shows, including NOVA and Today. His most recent popular book is The Diamond Makers, which recounts the discovery of a method to make synthetic diamonds. Robert Hazen is also a part-time professional trumpeter.