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.
Pagkatapos na iginawad sa kanyang titulo ng doktor sa 1937, siya-apply para sa isang scholarship na pumunta sa Johns Hopkins University ngunit ito ay hindi na iginawad sa kanya. Kac hindi bigyan up, gayunman, at ang mga sumusunod na taon siya-apply muli, at oras na ito siya ay matagumpay.