Since Newton, quantum theory has been the most ground-breaking advancement in physics. The surprising and paradoxical concepts that influence our understanding of the subatomic world are described in this book in a way that is lucid, engaging, and easy to understand. It doesn’t hide the interpretational issues that are still up for debate 75 years after the initial discoveries. Equations are not used in the main text, but a Mathematical Appendix is available for individuals who prefer more challenging material. Among the many subjects covered are uncertainty, probabilistic physics, complementarity, the difficulty of measurement, and decoherence. This book gives the reader access to one of the most important scientific discoveries and notable intellectual accomplishments of the 20th century.