We may have lived knowing that the world around us operates in a way as if we observe them to be. This knowledge of how the universe operates, based primarily of our observations, has enabled us to predict actions and motions and allowed us to build machines and equipments that have made our lives easier and more enjoyable. The field that allowed us to do that is classical physics. The world, however, is advancing and our knowledge of how things are expands over time. We have discovered in the last few decades that these sets of rules that we have devised can perfectly describe the large-scale world but cannot accurately define the behaviors of particles in the microscopic world. This necessitated another field to explain the different behavior in the microscopic world: quantum physics. Это и многое другое вы найдете в книге Quantum Physics For Beginners (Jason Stephenson)