Freeman John Dyson (born December 15, 1923) is an English-born American physicist and mathematician, famous for his work in quantum mechanics, nuclear weapons design and policy, and for his serious theorizing in futurism and science fiction concepts, including the search for extraterrestrial intelligence.

Career

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 - Richard Feynman's path integral formulation and the variational methods developed by Julian Schwinger and Sin-Itiro Tomonaga (Dyson operator).

From 1957 to 1961 he worked on the Orion Project, which proposed the possibility of space-flight using nuclear pulse 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.

In 1977, Dyson supervised Princeton undergraduate John Aristotle Phillips in a term paper that outlined a credible design for a nuclear weapon. This earned Phillips the nickname The A-Bomb Kid.

Alan Guth - "Eternal inflation: Successes and questions"

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.

Concepts

Dyson sphere

Main article: Dyson sphere

In 1960 Dyson wrote a short paper for the journal Science (vol. 131 p. 1667), entitled "Search for Artificial Stellar Sources of Infrared 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. Imaginitive 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 Stapledon 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 tree

Main article: Dyson tree

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's transform

Dyson also has some credits in Elementary number theory. His concept "Dyson's transform" led one of the most important lemmata of Olivier Ramaré's theorem that every integer is a sum of at most six primes.

Personal

He has six children. One daughter is Esther Dyson, the noted digital technology consultant. His son is the historian of technology George Dyson, one of whose books is Project Orion: The Atomic Spaceship 1957-1965. His wife, Imme Dyson, is an accomplished masters runner. Dyson's father was the renowned English composer George Dyson. Despite sharing a last name, he is not related to early 20th-century astronomer Frank Watson Dyson. However, as a small boy Freeman Dyson was aware of Frank Watson Dyson; Freeman credits the popularity of someone with the same last name with inadvertently helping to spark his interest in science. Dyson received a Sc.D. from Bates College in 1990. A boy in Tonganoxie, Kansas, USA, was named Dyson Felty in honor of Freeman Dyson (February 12 2000); when informed of this, Freeman Dyson unofficially adopted Dyson Felty as his godson.

The character of Gordon Freeman from Half-Life was partially inspired by Freeman Dyson.

See also

Books

• Brower, Kenneth, 1978. The Starship and the Canoe, Holt Rinehart and Winston.
  
• Schweber, Sylvan S., 1994. QED and the Men Who Made It: Dyson, Feynman, Schwinger, and Tomonaga . Princeton Univ. Press.
• L'importanza di essere imprevedibile, Di Renzo Editore, Roma, 2003
  

Links