As well as outlining and explaining such historic breakthroughs in human understanding of the physical world as Kepler s law of planetary motion and Newton s law of gravitation, Joanne Baker unravels the sometimes baffling complexities of modern scientific theory from Planck s law to Pauli s exclusion principle and from Schrondinger s cat to string theory. The essays are accompanied by a range of useful editorial features, including biographies of iconic physicists, timelines of related ideas, explanatory diagrams and display quotations.