Albert Einstein Boris Podolsky Nathan Rosen : can quantum mechanical description of physical reality be considered complete The work published by Einstein Podolsky and Rosen (EPR) in 1935 is a classic in modern physics. It discusses for the first time the central feature of the quantum theory: entanglement. In general systems are intertwined with each other in nature; that is they have only one common non divisible state. This fact is responsible for all the oddities commonly associated with quantum theory including the famous thought experiments with Schrödinger’s cat and Wigner’s friend. The entanglement of quantum mechanics plays a central role in experiments with atoms and photons (Nobel Prize 2012 for Haroche and Wineland) and the planned construction of quantum computers. This book presents EPR’s original work amplified with a detailed commentary which examines both the historical context and all aspects of entanglement. In particular it focuses on the interpretation of quantum theory and its consequences for a basic understanding of nature.