The longer you look, the more you get fooled. That's the excitement of optical illusion puzzles--especially when they are as colorful as these. Coins rearrange themselves. Pictures disappear and reappear. Your eyes are deceived, and you must figure out how; fortunately, your mind is sharper than your gaze. Start looking, get smart, and have fun. Eighty-two puzzles in all.

A fascinating collection of 270 visual conundrums to test your perception and boost your intelligence.

A rich assortment of visual mind-bogglers, including "impossible objects" — constructions that look fine on paper but can't possibly exist in reality — as well as pulsating patterns, vanishing spots, pictures that suddenly change into other configurations as you're looking at them, and much more. 60 black-and-white illustrations.

More than 135 puzzles, illusions, and activities in this four-color book, with answer key in the back. Features optical illusions, visual puzzles to challenge logic and spatial reasoning, and color-by-number illusions for readers to complete. Convenient spiral binding with colorful, appealing design throughout.

Practical guide shows how to set up working models of telescopes, microscopes, photographic lenses and projecting systems; how to conduct experiments for determining accuracy, resolving power, more. 234 diagrams.

Have you wondered why the sky is blue? Why the sunset is red? How hummingbirds show us their many colors? Why the road ahead sometimes seems to have water on it, when it does not? Have you wondered how telescopes work to give a magnified image of distant objects? How do microscopes provide a magnified image of close objects? How do spectroscopes, eye glasses, cameras, binoculars, and similar instruments work? How do the simple rear view mirrors in cars dim and provide wide fields of view? In this book, William L. Wolfe attempts to describe many of the natural phenomena caused by light, and the optical devices that use it in terms everyone can understand.