History of chemistry quantum mechanics were able to predict qualitatively some chemical features for biologically relevant molecules, they were, till the end of the 20th century, more a collection of rules, observations, and recipes than rigorous ab initio quantitative methods. This heuristic approach triumphed in 1953 when James Watson and Francis Crick deduced the double helical structure of DNA by constructing models constrained by and informed by the knowledge of the chemistry of the constituent parts and the X-ray diffraction patterns obtained by Rosalind Franklin. This discovery lead to an explosion of research into the biochemistry of life. In the same year, the
Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid which subsequently turned out to be incorrect. Both Crick, and particularly Watson, thought that they were racing against Pauling to discover the structure of DNA. Max Delbrück was a physicist who recognized some of the biological implications of quantum physics. Delbruck's thinking about the physical basis of life stimulated Erwin Schrödinger to write, "What Is Life?" Schrödinger's book was an important influence on Crick and Watson. Delbruck's efforts to promote the "Phage Group" (exploring genetics by way of the viruses that infect bacteria) was important in the early development of molecular biology in general and the development of Watson's scientific