The Discovery of the Ether -- The Ether and the Wave Equation -- The Physical Elements of the Special Theory of Relativity -- Where does the Wave Equation Come from? -- The Wave Equation and the Third Axiom Lattice and the Continuum Crystalline Solid - Dislocations -- The sine-Gordon Equation of a Dislocation Natural Measuring-Rods and Clocks Measuring-rods and Clocks in Motion -- A Clock Paradox Measurement of the Critical Velocity -- The Lorentz Transformation -- The Linear Approximation of Special Relativity -- The Principle of Relativity: The Lost Crystal -- Two Axiomatic Systems for Special Relativity -- The Twin Paradox.-The Doppler Effect. -- Aberration -- Tachyons and Causality Violation of Relativity -- The Rediscovered Crystal Particles and Fields -- A Particle Solution- the Inertia of Energy -- The Michelson Experiment -- Elastic Displacements and Waves -- Eigen -- Stresses and Dislocations -- The Separation of Eigen Stresses -- Particles and Tachyons -- Tachyons of the Plastic Deformation -- On the Problem of Causality: Particle -- Tachyon Collisions.