With 48 fact-filled cards per package, Knowledge Cards are a great source of condensed information all in a deck the size of a pack of playing cards. Card Size: 3¼ x 4 in. "How does catnip work its magic on cats? Why do the ice cubes in my freezer often develop stalagmite-like spikes? Did any dinosaurs have poisonous saliva, as in Jurassic Park ? The answers may surprise you. In this intriguing deck of cards, the Experts biologists, veterinarians, physicists, chemists, and others answer 48 questions from readers of Scientific American , one of the world s premiere sources of scientific information made comprehensible to the nonscientist. Packed with solid information and written in a casual style, Ask the Experts provides plenty of facts for trivia buffs and solves some of the mysteries of everyday life for the rest of us: Where does wind come from?"