On superconductivity and superfluidity (what I have and have not managed to do), as well as on the 'physical minimum' at the beginning of the 21 st century.

The question of thermeolectric effects in superconductors is still a particular problem, which evidently emerges only in the presence of a temperature gradient. The well-known Londons theory yielded much, and is widley employed under certain conditions even nowadays, but is absolutely insufficient and has to be generalized. This problem was solved in the psi-theory of superconductivity by V.L. Ginzburg and L.D. Landau. Together they developed a phenomenological theory of superconductivity in the late 1940s. This theory proposes that those electrons that contribute to superconduction form a superfluid. The superconductor is described by a complex function psi called the order parameter, and /psi/ indicates the fraction of electrons that has condensed into a superfluid. In his Nobel lecture V. L. Ginzburg also gives a 'list' of top problems in contemporary physics. Acquaintance with all subjects included in this 'list' is what he calls the 'physical minimum'.