The Curie principle and the Shubnikov system – to the further development of their ideas

The Curie principle, which establishes a relationship between the symmetries of a cause and its effect, was originally developed for finite bodies (crystals), but Pierre Curie himself noted the possibility of its application to extended media. This direction was initiated by the works of A. V. Shubnikov (crystalline media) and I.I. Shafranovsky (mother solution), and it requires further development. The systems of limiting symmetries for finite bodies and extended media are compared. The former is partially correlated with the symmetry system of crystallographic point groups. For the latter, in addition to the known data from Curie and Shubnikov, the introduction of new types of limiting symmetries is theoretically justified, and a general systematization is proposed.