"YOU HAVE CHANGED MY LIFE" is a common refrain in the emails Walter Lewin receives daily from fans who have been enthralled by his world-famous video lectures about the wonders of physics. "I walk with a new spring in my step and I look at life through physics-colored eyes," wrote one such fan. When Lewin's lectures were made available online, he became an instant YouTube celebrity, and The New York Times declared, "Walter Lewin delivers his lectures with the panache of Julia Child bringing French cooking to amateurs and the zany theatricality of YouTube's greatest hits." For more than thirty years as a beloved professor at the Massachusetts Institute of Technology, Lewin honed his singular craft of making physics not only accessible but truly fun, whether putting his head in the path of a wrecking ball, supercharging himself with three hundred thousand volts of electricity, or demonstrating why the sky is blue and why clouds are white. Now, as Carl Sagan did for astronomy and Brian Green did for cosmology, Lewin takes readers on a marvelous journey in For the Love of Physics, opening our eyes as never before to the amazing beauty and power with which physics can reveal the hidden workings of the world all around us. "I introduce people to their own world," writes Lewin, "the world they live in and are familiar with but don't approach like a physicist-yet."