From the phenomenon to the equations

The overestimating of heuristic possibilities of the mathematical methods in physics and the isolation from the reality are considered as one of the causes for the contemporary crisis in theoretical physics. The author shows that the generalization of the wave equation, diffusion equation and thermal conductivity equation for unhomogeneous medium are incorrect. The introduction of varying wave speed and coefficients of diffusion or thermal conductivity must be realized in first order equations. Correct second order differential equations are obtained. The laws of Fick and Fourier are connected with the absorption of a particle beam in atomic medium. The results show that the speed of diffusion and thermal conductivity is finite and coincide with the speed of its carriers - the particles of the medium. Equations for wave diffusion and thermal conductivity are obtained. It is pointed out that the temperature gradient is obtained from the absorption of the heat flow. Therefore the gradient can not be considered as a cause or a moving force of the heat flow. The situation with the diffusion is analogous. The method of deducing of Yukawa potential contradicts to the special theory of relativity which requires interaction propagation with the light speed. An analogical approach, subordinated to this relativistic requirement, leads to the force proposed by the author in which the Yukawa exponent is related to Newtonian force and not to Newtonian potential. The appearance of πo mesons is considered as a secondary effect. (author). 7 refs