David A. Adler is a former math teacher and author of more than two hundred books for children. He has collaborated on several science picture books with Anna Raff, including Light Waves and Magnets Push, Magnets Pull, both named finalists for the AAAS/Subaru SB&F Prize for Excellence in Science Books. He is also the author of the Picture Book Biography series and the Cam Jansen mystery series. He lives in New York. nAnna Raff is an award-winning illustrator of childrens books. She illustrated David A. Adlers Simple Machines and Things That Float and Things That Dont, which received starred reviews from Booklist and Publishers Weekly. She lives in New York City.n