What makes your stomach growl? Is it true that no two snowflakes are exactly alike? Why does popcorn pop? Maybe you've asked yourself questions like these; maybe your kids have asked you. The author of Newsday’s "How Come" column, Kathy Wollard, has the answers to these and hundreds of other questions in her new book "How Come: Every Kid's Science Questions Explained." She talks with Mark Heyne about her book and her career writing the “How Come” column and series.