The tautological toolkit -- Rise and fall : the logistic equation -- Mechanics and gravity : Newton's dynamical equations and universal law of gravity -- The electromagnetic force : the Lorentz force law -- A local conservation law : the continuity equation -- Electrodynamics : the Maxwell equations -- Electromagnetic waves : the wave equations -- Solitary waves : the Korteweg-De Vries equation -- Thermodynamics : the three laws of thermodynamics -- Kinetic theory : the Boltzmann equation -- Hydrodynamics : the Navier-Stokes equations -- Special relativity : relativistic kinematics -- General relativity : the Einstein equations -- Quantum mechanics : the Schrodinger equation -- The relativistic electron : the Dirac equation -- The strong force : quantum chromodynamics -- Electro-weak interactions : the Glashow-Weinberg-Salam model -- String theory : the superstring action --