The book comprises a series of authors personal texts on various subjects in Theoretical Physics. Some are easy writings, like those on our worlds numbers, main physical principles, numerical computation, probabilities, general laws of motion. Others deal with old subjects, like celestial mechanics, particles scattering, fluids, many-body dynamics, the Thomas-Fermi atom, superfluidity, liquids. New insights are obtained from old problems, included in these Lectures, like the relation between quantization and the non-inertial motion, or the curved spaces, the connection between teleportation...

Quantum Mechanics is a fundamental scientific discipline. At the same time, it is viewed as being very difficult. This book attempts to present the Theory of Quanta as a scientific discipline which has emerged naturally from experiment, making use of general concepts of the Classical Mechanics and enlarging their nature and applicability. According to the historical development, the first natural way of introducing the quantum-mechanical concepts is the matricial theory, followed by the very useful approach of the undulatory theory. The core of the Theory of Quanta is the quasi-classical...

The Theory of Quanta has a large area of applicability. Any motion, at the fundamental level, is quantum-mechanical, or includes quantum-mechanical motion. Quantum Mechanics encompasses motion forms from atoms, to atomic nuclei, molecules, chemical binding, electric and magnetic fields, electromagnetic radiation, and transport phenomena. The book includes such quantum-mechanical theories, both in their standard form and original versions, with emphasis on their physical contents. 1) Ch. 1, The Atom, besides standard subjects, presents a new, original formulation of the Thomas-Fermi theory,...

This book explores statistical physics, with an emphasis on the distinct character of the statistical motion and difficult subjects, related, mainly, to condensed matter. It discusses the interaction problem in real gases, as well as dimensionality effects and melting. The book shows how to estimate easily the critical temperature of the Ising ferromagnets, the origin of the drag force, how to get an inverse-wind vortex in turbulence, the entropy of the earthquakes, and how the gas-liquid transition occurs. It also describes the hadronization of the quark-gluon plasma, the phase diagram of...

This book presents the subject of physical kinetics from an original and unique angle, by deriving the Boltzmann equation from atomic motion, making extensive use of Landau's concept of elementary excitations. It includes external forces, besides statistical motion, in its treatment of the subject wherever relevant. It also details the kinetic theory of classical gas and its transport, devoting special attention to the classical plasma. In addition, the book emphasises the role played by the anharmonic interactions in the lifetime of phonons, and presents the basic features of...

This book presents an exploration of the wave and vibration equation in one, two and three dimensions, with emphasis on singular solutions. The distinction between the wave treatment and the vibration treatment is particularly discussed with the causality principle being the leading principle for waves in this context. The necessity of regularization of the singular solutions is presented whilst the scattered waves are differentiated from the reflected (and refracted) waves, according to Huygens principle. The physical content of the wave equation is underlined. Relevant applications are...

The interaction of bodies blurs the concept of independent particles. This book presents a way of accommodating the interaction in ensembles of many interacting fermions, like electrons in solids, or H e 3 at low temperatures. The theory of interacting fermions at zero temperatures is described, and its application to the quasiparticle picture is thoroughly investigated, with the aim of relating Landau's theory of the normal Fermi liquid to the quantum-mechanical interaction effects. The reader should have a background knowledge of quantum mechanics, statistical physics and quantum-field...