ABSTRACT
In the fifties, while investigating into the principles of relativity, I often discussed with Sergei Vasil'evich Vallander the problems set forth here and my conclusions. For this there were greater opportunities as we could then meet regularly in our office: in the spring of 1952 I was appointed as Rector of Leningrad University and invited Sergei V. Vallander to assist me as Deputy Rector in charge of academic research. Amidst the overwhelming flow of administrative drudgeries, we found a few moments for our scientific work.
