Physical world and mathematics

Ivan Stranski

Ivan Stranski (Иван Николов Странски) was a Bulgarian physical chemist who founded the molecular-kinetic theory of crystal growth and gave his name to the Stranski–Krastanov mechanism.

Ivan Vidav (1918–2015) was a Slovenian mathematician who founded the Slovenian school of functional analysis; his 1956 characterization of C-algebras among Banach algebras became the Vidav–Palmer theorem.

Ivan Vinogradov

Ivan Matveevich Vinogradov was a Soviet mathematician, a founder of modern analytic number theory, best known for his 1937 proof that every sufficiently large odd number is a sum of three primes.

Ivan Vsevolodovich Meshcherskiy

Ivan Vsevolodovich Meshcherskiy (Иван Всеволодович Мещерский) was a Russian mathematician and mechanician, born in 1859, who founded the mechanics of variable-mass bodies and wrote a theoretical-mechanics problem book still in print.

Ivan Yefremov (Иван Антонович Ефремов)

Ivan Yefremov (Иван Ефремов), also known as Ivan Antonovich Yefremov, was a Soviet paleontologist and science fiction writer, founder of taphonomy and author of Andromeda Nebula.

Ivanhoe Mines

Ivanhoe Mines is a Canadian mining company founded by Robert Friedland that develops the Kamoa-Kakula copper complex, the Kipushi zinc mine, and the Platreef platinum mine in Southern Africa.

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 Otto Bendixson

Ivar Otto Bendixson (1861–1935) was a Swedish mathematician, professor and rector at Stockholms högskola, who rigorously proved the Poincaré–Bendixson theorem in 1901 and proved Cantor's perfect-set result in 1883.

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.

Ives–Stilwell experiment

The Ives–Stilwell experiment was a 1938 physics experiment by Herbert E. Ives and G. R. Stilwell of Bell Telephone Laboratories that measured the second-order Doppler shift in light from fast-moving hydrogen particles.

Ivo Babuška

Ivo Babuška (1926–2023) was a Czech-American mathematician who established the mathematical foundations of the finite element method, leaving Czechoslovakia after the 1968 Soviet invasion for the University of Maryland and later UT Austin.

Iwasawa theory

Iwasawa theory is a branch of number theory, founded by Kenkichi Iwasawa in the late 1950s, that studies how class groups grow in infinite towers of number fields.

Oct 20, 2026

Iyang-Argapura

Iyang-Argapura (Iyang-Argopuro) is a 3,088 m eroded complex volcano in East Java between Raung and Lamongan; no major eruptions in 500 years, geothermal potential, Java's longest trek.

Izaak Kolthoff

Izaak Maurits Kolthoff was a Dutch-born American analytical chemist, professor at the University of Minnesota from 1927 to 1962, widely called the father of modern analytical chemistry.

Izod impact test

The Izod impact test is a pendulum test that breaks a notched, clamped specimen to measure impact resistance, defined for plastics by ASTM D256 and ISO 180.

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 Harlen Bretz

J Harlen Bretz (1882–1981) was an American geologist who showed in the 1920s that the Channeled Scabland of eastern Washington was carved by cataclysmic floods.

j-invariant

The j-invariant is a quantity attached to an elliptic curve, taking the same value on two curves exactly when they are isomorphic over an algebraically closed field.

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. A. Todd

J. A. Todd, full name John Arthur Todd (1908–1994), was an English mathematician at Cambridge known for the Todd genus, Todd class, and Todd–Coxeter algorithm.

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. Barkley Rosser

J. Barkley Rosser (1907–1989) was an American logician and mathematician who in 1936 strengthened Gödel's first incompleteness theorem to require only simple consistency, and later directed computing institutes at UCLA and Wisconsin.

J. C. Seamus Davis

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. Calvin Giddings

J. Calvin Giddings (1930–1996) was an American analytical chemist and Distinguished Professor at the University of Utah who invented field-flow fractionation and whose 1964 insight led to high-performance liquid chromatography.

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. David Lowell

J. David Lowell (James David Lowell; 1928–2020) was an American economic geologist from Tucson, Arizona, credited with more copper discoveries than anyone, including La Escondida in Chile.