Theodore Gray is the author of the bestselling The Elements: A Visual Exploration of Every Known Atom in the Universe and Theo Gray's Mad Science: Experiments You Can Do at Home, But Probably Shouldn't, and of Popular Science magazine's "Gray Matter" column.  He is the proprietor of periodictable.com.  He is also cofounder of Wolfram Research, creators of the world's leading technical software system, Mathematica and Wolfram Alpha.  With his company Touch Press, Gray is the developer of the bestselling iPad and iPhone ebook app, The Elements: A Visual Exploration and Solar System, also published in print by Black Dog & Leventhal.  He lives in Champaign-Urbana, Illinois.