Balungi explains deep ideas in physics in an easy-to-understand way. Think Physics is a series aimed to solving the big problems in physics. The book targets topics that researchers and students spend time wondering about, like the origin of gravity and the universe. It also goes into the theories that seem right but are wrong and shows why they are wrong a rarity in science books. Think Physics series is a rigorously correct, lighthearted, and cleverly designed problem solving book for physicists of all ages. Has been tested, rewritten, and retested to ensure that you can teach yourself all about major unsolved physics problems. Requires no math-mathematical treatments and applications are included in optional sections so that you can choose either a mathematical or nonmathematical approach. No Calculus