The Pocono Conference of 30 March to 2 April 1948 was the second of three postwar conferences held to discuss quantum physics; arranged by

Robert Oppenheimer J. Robert Oppenheimer (; April 22, 1904 – February 18, 1967) was an American theoretical physicist. A professor of physics at the University of California, Berkeley, Oppenheimer was the wartime head of the Los Alamos Laboratory and is often ...

for the National Academy of Sciences. It followed the

Shelter Island Conference The first Shelter Island Conference on the Foundations of Quantum Mechanics was held from June 2–4, 1947 at the Ram's Head Inn in Shelter Island, New York. Shelter Island was the first major opportunity since Pearl Harbor and the Manhattan Pro ...

of 1947 and preceded the Oldstone Conference of 1949. Held at the Pocono Manor Inn in the

Pocono Mountains The Pocono Mountains, commonly referred to as the Poconos , are a geographical, geological, and cultural region in Northeastern Pennsylvania. They overlook the Delaware River and Delaware Water Gap to the east, Lake Wallenpaupack to the north, ...

of Pennsylvania, midway between

Scranton, Pennsylvania Scranton is a city in the Commonwealth of Pennsylvania, United States, and the county seat of Lackawanna County. With a population of 76,328 as of the 2020 U.S. census, Scranton is the largest city in Northeastern Pennsylvania, the Wyoming V ...

and the

Delaware Water Gap Delaware Water Gap is a water gap on the border of the U.S. states of New Jersey and Pennsylvania where the Delaware River cuts through a large ridge of the Appalachian Mountains. The gap makes up the southern portion of the Delaware Water Gap ...

, 28 physicists attended. New participants were

Niels Bohr Niels Henrik David Bohr (; 7 October 1885 – 18 November 1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922 ...

Aage Bohr Aage Niels Bohr (; 19 June 1922 – 8 September 2009) was a Danish nuclear physicist who shared the Nobel Prize in Physics in 1975 with Ben Roy Mottelson and James Rainwater "for the discovery of the connection between collective motion and pa ...

Paul Dirac Paul Adrien Maurice Dirac (; 8 August 1902 – 20 October 1984) was an English theoretical physicist who is regarded as one of the most significant physicists of the 20th century. He was the Lucasian Professor of Mathematics at the Univer ...

Walter Heitler Walter Heinrich Heitler (; 2 January 1904 – 15 November 1981) was a German physicist who made contributions to quantum electrodynamics and quantum field theory. He brought chemistry under quantum mechanics through his theory of valence bond ...

Eugene Wigner Eugene Paul "E. P." Wigner ( hu, Wigner Jenő Pál, ; November 17, 1902 – January 1, 1995) was a Hungarian-American theoretical physicist who also contributed to mathematical physics. He received the Nobel Prize in Physics in 1963 "for his co ...

and

Gregor Wentzel Gregor Wentzel (17 February 1898 – 12 August 1978) was a German physicist known for development of quantum mechanics. Wentzel, Hendrik Kramers, and Léon Brillouin developed the Wentzel–Kramers–Brillouin approximation in 1926. In his early ...

; while Kramers, MacInnes, Nordsieck, Pauling and Van Vleck who were at the Shelter Island Conference were absent.

Julian Schwinger Julian Seymour Schwinger (; February 12, 1918 – July 16, 1994) was a Nobel Prize winning American theoretical physicist. He is best known for his work on quantum electrodynamics (QED), in particular for developing a relativistically invariant ...

gave a day-long presentation of his developments in

quantum electrodynamics In particle physics, quantum electrodynamics (QED) is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and spec ...

(QED), the ''last great fling of the old way of doing quantum mechanics''.

Richard Feynman Richard Phillips Feynman (; May 11, 1918 – February 15, 1988) was an American theoretical physicist, known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, the physics of the superfl ...

offered his version of quantum electrodynamics, introducing

Feynman diagrams In theoretical physics, a Feynman diagram is a pictorial representation of the mathematical expressions describing the behavior and interaction of subatomic particles. The scheme is named after American physicist Richard Feynman, who introduce ...

for the first time; it was unfamiliar and no-one followed it, so Feynman was motivated to go back to

Cornell Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teach a ...

and write his work up for publication so others could see it in cold print. Schwinger and Feynman compared notes; and although neither could really understand the other’s approach, their arrival at the same answer helped to confirm the theory. And on his return to Princeton University, Princeton, Oppenheimer received a third version by Sin-Itiro Tomonaga; his version of QED was somewhat simpler than Schwinger's. Griffin (1997) p. 108

References

* *{{cite book , last=Mehra , first= Jagdish , title=The Beat of a Different Drum: The life and science of Richard Feynman , year= 1994 , publisher=Clarendon Press , location= Oxford, England , isbn= 0-19-853948-7 , pages=245–249 Physics conferences History of science and technology in the United States Foundational quantum physics 1948 in science 1948 in the United States 1948 conferences 1948 in Pennsylvania Science events in the United States April 1948 events in the United States