Physicists and astronomers

Ivan R. King

Ivan R. King (1927–2021) was an American astronomer who spent most of his career at UC Berkeley; his King models became the standard description of globular cluster light profiles.

Ivar Giaever

Ivar Giaever, also Ivar Giæver, was a Norwegian-born American physicist at General Electric in Schenectady who shared the 1973 Nobel Prize in Physics for measuring the superconducting energy gap.

Ivar Waller

Ivar Waller (1898–1991) was a Swedish theoretical physicist who gave the quantum description of X-ray scattering by crystal lattice vibrations, the Debye–Waller factor, and was professor at Uppsala.

Izuo Hayashi

Izuo Hayashi was a Japanese physicist who, with Morton Panish at Bell Labs, demonstrated in 1970 a semiconductor laser running continuously at room temperature, enabling optical communications.

J. A. Ratcliffe

J. A. Ratcliffe, known as John Ashworth Ratcliffe, was a British radio physicist at Cambridge who helped prove radio waves reflect from the ionosphere and trained wartime radar scientists.

J. Allen Hynek

J. Allen Hynek (Josef Allen Hynek) was an American astronomer who advised the Air Force's Project Blue Book and coined "close encounters of the third kind."

Sep 20, 2026

J. Andrew McCammon

J. Andrew McCammon is an American theoretical chemist and biophysicist at UC San Diego who performed the first molecular dynamics simulation of a protein in 1976.

J. B. Gunn

J. B. Gunn (John Battiscombe Gunn) was a British physicist at IBM who discovered the Gunn effect in 1963, the microwave oscillation that led to the Gunn diode.

J. C. Seamus Davis is an Irish condensed-matter physicist from Skibbereen, County Cork, who builds scanning tunneling microscopes to visualize quantum matter and detected Cooper-pair density waves in superconductors.

J. Curry Street

Jabez Curry Street was an American experimental physicist at Harvard whose 1937 cosmic-ray measurement with E. C. Stevenson identified the muon; he chaired Harvard's physics department from 1955 to 1960.

J. D. Bernal

J. D. Bernal (1901–1971), 'Sage', Irish-born British X-ray crystallographer at Cambridge and Birkbeck College; pioneered protein crystallography with Crowfoot, modeled water structure with Fowler, mentored Nobel laureates Hodgkin, Perutz, Klug.

J. Gary Eden

J. Gary Eden is an American electrical engineer and applied physicist at the University of Illinois, elected to the National Academy of Engineering in 2014 for microplasma technologies and excimer lasers.

J. Georg Bednorz

J. Georg Bednorz, also known as Georg Bednorz, is a German physicist who discovered high-temperature superconductivity in 1986 and won the 1987 Nobel Prize in Physics.

J. Hans D. Jensen

J. Hans D. Jensen, born Johannes Hans Daniel Jensen (1907–1973), was a German nuclear physicist at Heidelberg who shared the 1963 Nobel Prize in Physics for the nuclear shell model.

J. J. Thomson

J. J. Thomson, born Joseph John Thomson, was an English physicist who discovered the electron in 1897 and won the 1906 Nobel Prize in Physics.

J. Michael Kosterlitz

J. Michael Kosterlitz, born John Michael Kosterlitz in 1943, is a British condensed-matter physicist at Brown University known for the Kosterlitz–Thouless transition and the 2016 Nobel Prize in Physics.

J. Randall Jokipii

J. Randall Jokipii, born Jack Randolph Jokipii (1939–2022), was an American space physicist at the University of Arizona known for his theory of cosmic-ray transport in the heliosphere.

J. Richard Bond

J. Richard Bond, born John Richard Bond in 1950, is a Canadian theoretical cosmologist at the University of Toronto who won the 2025 Shaw Prize in Astronomy.

J. Richard Fisher

J. Richard Fisher is an astronomer at the National Radio Astronomy Observatory who co-discovered the Tully–Fisher relation with R. Brent Tully in 1977, a key method for measuring galaxy distances.

J. Robert Oppenheimer

J. Robert Oppenheimer, born Julius Robert Oppenheimer (1904–1967), was an American theoretical physicist who led development of the first atomic bombs as director of the Los Alamos Laboratory.

J. S. E. Townsend

J. S. E. Townsend, born John Sealy Edward Townsend in Galway, Ireland, was an Irish physicist who held the Wykeham Professorship of Experimental Physics at Oxford from 1900 to 1941.

J. van Paradijs

Jan van Paradijs (1946–1999) was a Dutch high-energy astrophysicist who measured the first neutron star mass and found the first gamma-ray-burst optical afterglow in 1997.

J.‐F. Donati

Jean-François Donati is a French astrophysicist and CNRS research director at IRAP in Toulouse, known for mapping stellar magnetic fields and leading the ESPaDOnS and SPIRou instruments.

Jaan Einasto

Jaan Einasto, born 1929 in Tartu, Estonia, is an Estonian astrophysicist who helped discover dark matter around galaxies and the cosmic web, and created the Einasto profile.

Jack J. Lissauer

Jack J. Lissauer is a space scientist at NASA's Ames Research Center, best known for identifying resonance features in Saturn's rings and discovering the six-planet system Kepler-11 in 2011.

Jack Kilby

Jack Kilby (Jack St. Clair Kilby) was an American engineer at Texas Instruments who built the first integrated circuit in 1958 and shared the 2000 Nobel Prize in Physics.

Jack M. Mochel

Jack M. Mochel is a low-temperature physicist at the University of Illinois at Urbana-Champaign known for third-sound experiments on thin superfluid helium films.

Jack R. Jokipii

Jack R. (Randy) Jokipii (1939–2022) was an American space plasma and cosmic-ray physicist, Regents Professor at the University of Arizona, known for quasi-linear theory and the 22-year cosmic-ray cycle.

Jack Sandweiss

Jack Sandweiss (1930–2020) was an American experimental particle and nuclear physicist at Yale University from 1957, a National Academy of Sciences member, and editor of Physical Review Letters for 25 years.