Book excerpt: How heavy is that cloud? Why can you see farther in rain than in fog? Why are the droplets on that spider web spaced apart so evenly? If you have ever asked questions like these while outdoors, this book isfor your. An entertaining and informative collection of fascinating puzzles from the natural world around us, A Mathematical Nature Walk will delight anyone who loves nature or math or both. John Adam presents ninety-six questions about natural phenomena and then shows how to answer them using mostly basic mathematics. Many of the problems are illustrated, and the book also has answers, a glossary of terms, and a list of patterns found in nature. Regardless of math background, readers will learn from the informal descriptions of the problems and gain a new appreciation of the beauty of nature and the mathematics that lies behind it. --