Steady-State Theory at Chicago

In papers published in 1918 and 1925 W. D. MacMillan suggested that the universe maintains a steady state in its large-scale astronomical features, as a result of a balance between matter-to-energy conversion in stellar interiors and creation of atoms from radiant energy in empty space. No mechanism for the atom-creation process in space was suggested. R. A. Millikan used the MacMillan theory as a basis for a theory of the origin of cosmic rays, but in a few years' time accumulating evidence made that theory untenable, and interest in the MacMillan theory then also dropped. Similarities between the MacMillan and Bondi-Gold-Hoyle steady-state theories are noted.