What Is Life? published in 1944. At that time DNA was not yet accepted as the carrier of hereditary information, which only was the case after the Hershey–Chase experiment of 1952. One of the most successful branches of physics at this time was statistical physics, and quantum mechanics, a theory which is also very statistical in its nature. Schrödinger himself is one of the founding fathers of quantum mechanics. Max Delbrück's thinking about the physical basis of life was an important influence on Schrödinger. However, long before the publication of "What is Life?", geneticist and 1946 Nobel-prize winner H. J. Muller had in
History of variational principles in physics History of variational principles in physics A variational principle in physics is an alternative method for determining the state or dynamics of a physical system, by identifying it as an extremum (minimum, maximum or saddle point) of a function or functional. This article describes the historical development of such principles. Variational principles are found among earlier ideas in surveying and optics. The rope stretchers of ancient Egypt stretched corded ropes between two points to measure the path which minimized the distance of separation, and Claudius Ptolemy, in his Geographia (Bk 1, Ch 2), emphasized that one must correct for "deviations