This richly illustrated book is unique in bringing Einstein's relativity to a higher level for the non-specialist than has ever been attempted before, using nothing more than grade-school algebra. Bondi's approach with spacetime diagrams is simplified and expanded, clarifying the famous asymmetric aging-of-twins paradox. Einstein's theory of gravity, general relativity, is simplified for the reader using spacetime diagrams. The theory is applied to important topics in physics such as gravitational waves, gravitational collapse and black holes, time machines, the relationship to the quantum world, galactic motions and cosmology.