Classic introduction to Einstein's theory, written by a prominent physicist, provides the two main postulates upon which the theory rests and their experimental evidence. The relation between relativity theory and the principle of least action is discussed, as is a four-dimensional method of expressing and treating the results of relativity theory. 1917 edition.
Richard Chace Tolman (March 4, 1881 – September 5, 1948) was an American mathematical physicist and physical chemist who was an authority on statistical mechanics. He also made important contributions to theoretical cosmology in the years soon after Einstein's discovery of general relativity. He was a professor of physical chemistry and mathematical physics at the California Institute of Technology (Caltech).