This book provides a description of the evolution of the concepts of causality and time through modern physics considering first relativity theories and them quantum mechanics. Relativity, at least in the form given by Einstein, denies reality of past, present and future and does not indicate a time direction. On the other hand a time direction is indicated by all the phenomena we observe including our own existence. Quantum mechanics seems to indicate a different story. It is argued that, because of its non deterministic character, it is capable to indicate an objective time direction. This occurs through the phenomena of wave function collapse and entanglement which are discussed at length.