In 1934, Orowan wrote his famous paper on dislocations. He had been doing the experiments, while still in Berlin, which supported the theory put forward in Becker's 1925 paper. In 1934, Orowan, roughly contemporarily with G. I. Taylor and Michael Polanyi, realized that the plastic deformation of ductile materials could be explained in terms of the theory of dislocations developed by Vito Volterra in 1905. Though the discovery was neglected until after World War II, it was critical in developing the modern science of solid mechanics.