In 1953 and 1954 Russian-American theoretical physicist, cosmologist and science writer George Gamow, while at George Washington University, came up with the idea of a genetic code in his paper “Possible Mathematical Relation between Deoxyribonucleic Acids and Proteins” (Det. Kongelige Danske Videnskabernes Selskab: Biologiske Meddeleiser 22, no. 3  1-13).
In the fall of 1953 Gamov gave Crick an earlier draft of this paper entitled “Protein synthesis by DNA molecules.”
“Gamov’s scheme was decisive, Crick has often said since, because it forced him, and soon others, to begin to think hard and from a particular slant—that of the coding problem—about the next stage, now that the structure of DNA was known” (Judson,The Eighth Day of Creation, 236).