Professor Freeman Dyson worked as an analyst for British Bomber Command during World War II. After the war, he obtained a BA degree in mathematics from Cambridge University (1945) and was a Fellow at Trinity College, Cambridge from 1946 to 1949. In 1947 he moved to the US, on a fellowship at Cornell University and then joined the faculty there as a physics professor in 1951 without a PhD. In 1953, he took up a post at the Institute for Advanced Study in Princeton, NJ. In 1957, he became a naturalized citizen of the United States. In the years following the war, Dyson was responsible for demonstrating the equivalence of the two formulations of quantum electrodynamics which existed at the time From 1957 to 1961 he worked on the Orion Project, which proposed the possibility of space-flight using nuclear propulsion. A prototype was demonstrated using conventional explosives, but a treaty banning the use of nuclear weapons in space caused the project to be abandoned. Dyson has published a number of collections of speculations and observations about technology, science, and the future: • The Sun, The Genome and The Internet • Imagined Worlds • From Eros to Gaia • Disturbing the Universe Dyson was awarded the Lorentz Medal in 1966 and Max Planck medal in 1969. In the 1984–85 academic year he gave the Gifford lectures at Aberdeen, which resulted in the book Infinite In All Directions. In 1998, Dyson joined the board of the Solar Electric Light Fund. In 2000, Dyson was awarded the Templeton Prize for Progress in Religion.As of 2003, Dyson is the president of the Space Studies Institute, the space research organization founded by Gerard K. O'Neill. Dyson was a long time member of the JASON defense advisory group. In 1959 Dyson wrote a short paper for the journal Science, entitled "Search for Artificial Stellar Sources of Infra-Red Radiation". In it, he theorized that a technologically advanced society might completely surround its native star in order to maximize the capture of the star's available energy. Eventually, the civilization would completely enclose the star, intercepting electromagnetic radiation with wavelengths from visible light downwards and radiating waste heat outwards as infrared radiation. Therefore, one method of searching for extraterrestrial civilisations would be to look for large objects radiating in the infrared range of the electromagnetic spectrum. Dyson conceived that such structures would be clouds of asteroid-sized space habitats, though science fiction writers have preferred a solid structure: either way, such an artifact is often referred to as a Dyson sphere, although Dyson himself used the term "shell". Dyson says (20 minutes into a video) that he used the word "artificial biosphere" in the article meaning a habitat, not a shape. Imaginative science fiction writers (specifically Olaf Stapledon) then expanded on what Dyson says was really his humor tacked on at the end of the article. Dyson says it should really be called the Stapleton Sphere. One of the most famous science fiction examples was illustrated in an episode of Star Trek: The Next Generation, in which retired Engineer Scotty (from the original Star Trek) was found to have crash-landed on an abandoned Dyson sphere. Larry Niven's novel Ringworld was based on Dyson's concept, and was a scientifically detailed attempt to visualize a much simpler structure. Dyson has also proposed the creation of a Dyson tree, a genetically-engineered plant capable of growing on a comet. He suggested that comets could be engineered to contain hollow spaces filled with a breathable atmosphere, thus providing self-sustaining habitats for humanity in the outer solar system. Dyson also has some credits in Elementary number theory. His concept "Dyson's transform" lead one of the most important lemmata of Olivier Ramaré's theorem that every integer is a sum of at most six primes. Dyson received a Sc.D. from Bates College in 1990.