DANA MACKENZIE holds a doctorate in mathematics from Princeton University. After teaching mathematics at Duke University and Kenyon College for more than a decade, in 1997 he completed the Science Communication Program at the University of California at Santa Cruz. Since then he has been a freelance science writer, with articles appearing in such magazines as Science, Discover, American Scientist, Astronomy, and New Scientist. He lives in Santa Cruz with his wife as well as three cats and a dog.