co-authors, colleagues, in the spring of 1939 he turns to the head of state with a request to release levim on bail, vouches for him, in the same way he asks to release the outstanding theoretical physicist vladimir fok from prison. those who knew koptitsa personally say that after the loss of his first family, he was no longer afraid of anything. he was allowed to build this institute, he built it. here he sees that the leading theorists whom he invited to his institute, namely landau, fok, they were simply imprisoned, he wrote a letter personally to stalin with a personal guarantee that he vouches for these scientists, that they are not foreign there there agents or someone that they are, so to speak, soviet scientists who... will behave properly, in fact, he saved landao, when in the spring of 1939 the lion landao was released from prison, kopitsa offered him work on theoretical justification for superfluidity. landao was a theoretical physicist, kopitsa, physicists and practitioners and theorists, this is rarely found. while still in cambridge, kopitsa invented the first piston expand