This book proposes a new interpretation of the main concepts of Theoretical Physics. Rather than offering an interpretation based on exotic physical assumptions (additional dimension, new particle, cosmologic phenomenon,…) or a brand new abstract mathematic formalism, it proceeds to a systematic review of the main concepts of Physics, as Physicists have always understood them : space, time, material body, force fields, momentum, energy… and propose the right mathematical tools to deal with them, chosen among well known mathematical theories. After a short introduction about the place of Mathematics in Physics, a new interpretation of the main axioms of Quantum Mechanics is proposed. It is proven that these axioms come actually from the way mathematical models are expressed, and this leads to theorems which validate most of the usual computations and provide safe and clear conditions for their use, as it is shown in the rest of the book. Relativity is introduced through the construct of the Geometry of General Relativity, based on 5 propositions and the use of tetrads and fiber bundles, which provide tools to deal with practical problems, such as deformable solids. A review of the concept of momenta leads to the introduction of spinors, as their main representation for particles, in the framework of Clifford algebras. It gives a clear understanding of spin and antiparticles. The force fields are introduced through connections, in the, now well known, framework of gauge theories, which is here extended to the gravitational field. It shows that this field has actually a rotational and a transversal components, which are masked under the usual treatment by the metric and the Levy-Civita connection, and have a different physical meaning. A thorough attention is given to the topic of the propagation of all the fields, which, by a full representation in fiber bundles, are easily quantized, with interesting results related notably to their range. The general theory of lagrangians in the application of the Principle of Least Action is reviewed, and two general models, incorporating all particles and fields are explored, and used for the introduction of the concepts of currents and energy-momentum tensor. As a particular result it appears that the two components of the gravitational fields can have opposite action, which can itself depend on the speed of the material body. All the material is given to model, in a manageable way, the behavior of large stars systems. The last chapter shows that bosons can be understood as discontinuities in the fields. In this third version somme additions are made on Clifford algrbras and connections, and a more comprehensive treatment of the propagation of fields provides a manageable solution of the models. Moreover the representation of bosons as discontinuities is refined and improved.