When was the Jurassic Period? How do bionic parts work? Is there a face on Mars? While most dictionaries and science books only tell you the answers, The Ultimate Visual Dictionary of Science shows you! Each picture is an accompanied by concise, clear explanations that make the most complex subjects easy to understand., Over 200,000 words. More than 1,400 color photographs and 200 illustrations. A companion volume to the hugely successful Ultimate Visual Dictionary.