Physical and mathematical scientists

Olof Hanner

Olof Hanner (1922–2015) was a Swedish mathematician, professor at the University of Gothenburg from 1963 to 1989, known for the Hanner inequality and Hanner polytopes.

G. Olof Thorin (1912–2004) was a Swedish mathematician who spent his career as an insurance actuary, never at a university, and proved the Riesz–Thorin interpolation theorem, still standard teaching material.

Omar Azzaroni

Omar Azzaroni, born in 1974, is an Argentine chemist at the Universidad Nacional de La Plata known for supramolecular materials, polymer thin films, and solid-state nanopores.

Omar K. Farha

Omar K. Farha is a Palestinian-born chemist at Northwestern University, chair of its chemistry department since 2024, known for record-setting metal–organic frameworks for gas storage and destroying chemical warfare agents.

Omar Yaghi

Omar M. Yaghi (عمر ياغي), born 1965 in Amman, Jordan, is a chemist at UC Berkeley who founded reticular chemistry and won the 2025 Nobel Prize in Chemistry for metal-organic frameworks.

Ondrej Krivanek

Ondrej Krivanek (Ondřej Křivánek) is a Czech-British physicist who designed the first practical aberration corrector for electron microscopes, co-founded Nion, and won the 2020 Kavli Prize.

Ora Mendelsohn Rosen

Ora Mendelsohn Rosen (1935–1990) was an American biochemist who showed the insulin receptor is an insulin-activated tyrosine kinase, helped clone its gene in 1985, and led research at Einstein and Sloan Kettering.

Oren Scherman

Oren A. Scherman is a professor of supramolecular and polymer chemistry at the University of Cambridge, known for self-healing cucurbituril-based materials and directing the Melville Laboratory for Polymer Synthesis.

Oreste Piccioni

Oreste Piccioni (1915–2002) was an Italian experimental particle physicist, the last of Enrico Fermi's students, who co-discovered the antineutron in 1956 and long disputed his exclusion from the 1955 antiproton discovery.

Ortwin Hess

Ortwin Hess is a theoretical physicist working in quantum nanophotonics and metamaterials at Trinity College Dublin, known for the 2007 trapped rainbow principle and the Royal Society's Rumford Medal.

Orville Frank Tuttle

Orville Frank Tuttle (1916–1983) was an American experimental petrologist who showed that granite forms from a water-bearing melt and designed the Tuttle bomb pressure vessel.

Sep 17, 2026

Orville L. Chapman

Orville L. Chapman, born Orville Lamar Chapman (1932–2004), was an American organic chemist and UCLA professor who pioneered low-temperature trapping of reactive intermediates and synthesized carpanone in one step.

Osamu Ishitani

Osamu Ishitani (石谷治) is a Japanese photochemist known for rhenium and ruthenium–rhenium photocatalysts that convert carbon dioxide to carbon monoxide or formic acid, and a professor at Hiroshima University.

Osamu Sato

Osamu Sato (佐藤治) is a Japanese materials and coordination chemist, a professor at Kyushu University known for photomagnetism, spin crossover, and dynamic molecular crystals, and for his 1996 Science paper on photoinduced magnetization.

Osamu Terasaki

Osamu Terasaki is a Japanese electron crystallographer known for solving the atomic structures of zeolites, mesoporous materials, and metal-organic frameworks by electron microscopy, with careers at Tohoku and Stockholm universities.

Oscar K. Rice

Oscar Knefler Rice (1903–1978) was an American physical chemist at the University of North Carolina, elected to the National Academy of Sciences in 1964, known for unimolecular reaction theory.

Oscar Loew

Oscar Loew (1844–1941) was a German agricultural chemist who announced catalase in 1900, discovered manganese as a plant nutrient, and taught in Tokyo and Munich.

Oscar Randal-Williams

Oscar Randal-Williams is a mathematician at the University of Cambridge, the Sadleirian Professor of Pure Mathematics, known for work on moduli spaces of manifolds with Søren Galatius.

Oscar Schlömilch

Oscar Schlömilch (1823–1901) was a German mathematician, professor in Dresden, founding editor of the Zeitschrift für Mathematik und Physik, and namesake of the Schlömilch series, an 1857 expansion in Bessel functions.

Oscar W. Greenberg

Oscar W. Greenberg is an American physicist who in 1964 introduced the three-valued quark charge now called color, resolving the spin-statistics paradox and providing an ingredient of quantum chromodynamics.

Oscar Zariski

Oscar Zariski, born Asher Zaritsky, was an American mathematician who rebuilt the foundations of algebraic geometry on commutative algebra, teaching at Johns Hopkins and then Harvard until 1969.

Oskar Backlund

Oskar Backlund, known in Russia as Oskar Andreevich Baklund, was a Swedish-born astronomer who directed the Pulkovo Observatory from 1895 to 1916 and studied Encke's comet.

Oskar Bolza

Oskar Bolza (1857–1942) was a German mathematician known for the problem of Bolza in the calculus of variations, who taught at the University of Chicago from 1892 to 1910.

Oskar Klein

Oskar Benjamin Klein (1894–1977) was a Swedish theoretical physicist and longtime collaborator of Niels Bohr, known for the Klein–Gordon equation, Kaluza–Klein theory, and the Klein–Nishina formula.

Oskar Painter

Oskar Painter, born 1972, is an experimental physicist and Caltech professor known for optomechanical crystals, who since December 2019 has directed quantum hardware at Amazon Web Services.

Oskar Perron

Oskar Perron (1880–1975) was a German mathematician who held chairs at Heidelberg and Munich and is known for the Perron–Frobenius theorem, the Perron integral, and continued fractions.

Oskar Wintersteiner

Oskar Wintersteiner (1898–1971) was an Austrian-American biochemist who first crystallized penicillin and showed it contained sulfur, and who isolated progesterone and helped isolate cortisone at Squibb.

Osmond Fisher

Osmond Fisher (1817–1914) was an English clergyman and geologist, rector of Harlton, who wrote the first geophysics textbook, The Physics of the Earth's Crust (1881), anticipating convection currents and continental mobility.

Ossian Aschan

Adolf Ossian Aschan (1860–1939) was a Finnish organic chemist and politician, professor of chemistry at the University of Helsinki from 1908 to 1927 and a member of Parliament in 1910–1911.