in 2007 that Columbia University has decided to junk a 70-year-old atom smasher, which is the nation's oldest artefact of the nuclear era. After being decommissioned in 1965, the machine sat in the basement of Pupin Hall, home of Columbia's physics department. It was scrapped in 2008, although some components are in the Smithsonian Institution in Washington, DC. In December 1938, the German chemists Otto Hahn and Fritz Strassmann sent a manuscript to Naturwissenschaften reporting they had detected the element barium after bombarding uranium with neutrons. They communicated these results to Lise Meitner, who, with her nephew Otto Frisch, correctly interpreted these results as being the result of nuclear fission. Frisch then confirmed this experimentally on January 13, 1939. Even before it was published, Meitner’s and Frisch’s interpretation of the work of Hahn and Strassmann crossed the Atlantic Ocean with Niels Bohr, who was to lecture at Princeton University. Isidor Isaac Rabi and Willis Lamb, two Columbia University physicists working at Princeton, heard the news and carried it back to Columbia. Rabi said he told Fermi; Fermi gave credit to Lamb. It was soon clear to a number of scientists at Columbia that they should try to detect the energy released in the nuclear fission of uranium from neutron bombardment. On 25 January 1939, Dunning was a member of the Columbia team that conducted the first nuclear fission experiment in the United States. in the Other members of the team were Herbert L. Anderson, Eugene T. Booth, Enrico Fermi, G. Norris Glasoe, and Francis G. Slack. Bohr argued that it was the uranium-235 isotope that was responsible for fission. Dunning realised that if this was the case, then an atomic bomb would be possible. His thoughts turned to devising a process for uranium enrichment, and by 1940 he was investigating gaseous diffusion, which he felt appeared to be more effective than the electromagnetic method of Alfred Nier and offered the best route to enrichment on an industrial scale. The researchers at Columbia became the Manhattan Project's Substitute Alloy Materials (SAM) Laboratories. Dunning headed the laboratory division responsible for all aspects of the gaseous diffusion program, including engineering problems, pilot plants and research activities. Four papers co-written with James Rainwater, William W. Havens, Jr., and Chien-Shiung Wu appeared in 1947 and 1948, but much remained classified. Due to the secrecy of this work, Dunning and three of his colleagues were awarded