Quantum mechanics is the most successful theory in science and the basis for one-third of our economy. Its history is a long and rich one, and even today remains a controversial topic of discussion for scientists, interested laypersons, and the media. In attempts to understand the atom, physicists built quantum mechanics and found, to their embarrassment, that their theory intimately connects consciousness with the physical world. The implications of this connection are heatedly controversial, and explain why some founders of the theory quickly became its opponents. Schrodinger, for example, proved that the theory "absurdly" allowed a cat to be in a "superposition" simultaneously dead and alive. Einstein derided the theory's "spooky interactions." With Bell's Theorem, we now know Schrodinger's superpositions and Einstein's spooky interactions do indeed exist. In Quantum Enigma, Bruce Rosenblum and Fred Kuttner explain the theory of quantum mechanics and the mystery surrounding it in non-technical terms, using fanciful stories and anecdotes about the theory's developers. With a light and, at times, humorous presentation, they expertly explore the controversial connections between physics and consciousness, highlighting the points at which these intersect with the fundamentals of quantum mechanics. Though the book does delve into the realm of the unknowable, its description of the experimental quantum facts, and the quantum theory explaining them, is a matter of undisputable scientific fact. Readers are armed with the fundamentals of quantum mechanics and brought to a boundary where the expertise of physicists is no longer a sure guide. Instead of a manual to navigate the mysteries of physics, they will be given the tools they need to speculate for themselves. Since the first edition was published, interest in the quantum mystery has increased in both academic and industrial research, as well as in the media. The topic has been featured in academic publications in physics, psychology and philosophy, and has made its way into popular literature and general science magazines. The second edition builds upon the fine scholarship contained in the first edition. All chapters are updated to reflect recent advancements in quantum mechanics, while explanations within chapters are improved to increase clarity, in response to feedback from readers and instructors who have adopted the book. A completely new chapter, "Experimental Metaphysics," that describes the results of the most recent experiments that deal with quantum mysteries, will be added, as will a preface to the second edition. The illustrations that occur throughout the first edition will be redrawn.