After being awarded his doctorate in 1937, he applied for a scholarship to go to Johns Hopkins University but it was not awarded to him. Kac did not give up, however, and the following year he applied again, and this time he was successful.
Pärast seda antakse doktorikraadi aastal 1937 taotles ta stipendiumi minna Johns Hopkins University, kuid seda ei antud talle. Kac ei anna, aga, ja järgmisel aastal taotles ta uuesti, ja seekord oli ta edukas.