For his services as director of Los Alamos, Oppenheimer was awarded the Medal for Merit by President Truman in 1946. Postwar activities The Manhattan Project was top secret and did not become public knowledge until after the bombings of Hiroshima and Nagasaki, and Oppenheimer became a national spokesman for science who was emblematic of a new type of technocratic power. He became a household name and his portrait appeared on the covers of Life and Time. Nuclear physics became a powerful force as all governments of the world began to realize the strategic and political power that came with nuclear weapons. Like many scientists of his generation, he felt that security from atomic bombs would come only from a transnational organization such as the newly formed United Nations, which could institute a program to stifle a nuclear arms race. Institute for Advanced Study In November 1945, Oppenheimer left Los Alamos to return to Caltech, but soon found that his heart was no longer in teaching. In 1947, he accepted an offer from Lewis Strauss to take up the directorship of the Institute for Advanced Study in Princeton, New Jersey. This meant moving back east and leaving Ruth Tolman, the wife of his friend Richard Tolman, with whom he had begun an affair after leaving Los Alamos. The job came with a salary of $20,000 per annum, plus rent-free accommodation in the director's house, a 17th-century manor with a cook and groundskeeper, surrounded by of woodlands. He collected European furniture, and French post-impressionist and Fauvist artworks. His art collection included works by Cézanne, Derain, Despiau, de Vlaminck, Picasso, Rembrandt, Renoir, Van Gogh and Vuillard. Oppenheimer brought together intellectuals at the height of their powers and from a variety of disciplines to answer the most pertinent questions of the age. He directed and encouraged the research of many well-known scientists, including Freeman Dyson, and the duo of Chen Ning Yang and Tsung-Dao Lee, who won a Nobel Prize for their discovery of parity non-conservation. He also instituted temporary memberships for scholars from the humanities, such as T. S. Eliot and George F. Kennan. Some of these activities were resented by a few members of the mathematics faculty, who wanted the institute to stay a bastion of pure scientific research. Abraham Pais said that Oppenheimer himself thought that one of his failures at the institute was being unable to bring together scholars from