Based on the principle of symmetry, we propose a universal expression of the energy of physical system. If we accept a generalized coordinate as an argument, we come to potential energy; if we accept a generalized velocity as an argument, we come to kinetic co-energy. Here, like in the variational principle, the concept of kinetic energy does not work. The examples of application relate to electromagnetic fields, electromagnetic circuits, and mechanics of concentrated masses.
The method of the research relates to the theoretical tectonophysics. We study the question of the sources of energy of tectonic processes in the crust and lithosphere. They is divided into internal and external. Internal sources include the processes associated with the inversion density created during sedimentation in horizontally stratified array, as well as resulting from thermal heating due to the approach to the base of the lithosphere of the anomalous mantle.