What is quantum physics? Quantum physics is the physics of sub atomic particles, and, unlike the predictable format of classical physics, quantum physics appears to be totally indeterminate, which makes it a very exciting subject to study. In this book, we look at the energy associated with quantum particles, usually photons of electromagnetic radiation. We then examine how to determine the distance between electron shells in hydrogen atoms, and finally we consider the Rydberg constant which will enable us to calculate the wavelength of the photons that can be emitted from an electron collapse between shells. We also consider the time independent form of the Schr dinger equation in order to examine the phenomenon of quantum tunnelling. We then consider the philosophical side of quantum theory, not least of which is the multiple state theory, which, of course, is mathematically faultless. We complete our book by examining the possibility that the whole Universe developed all possible histories and when, so called, intelligent life evolved, the finely tuned constants of the Universe were locked in our part of the history.