Physical world and mathematics

Hyron Spinrad

Hyron Spinrad (1934–2015) was an American astronomer and UC Berkeley professor who detected water vapor on Mars in 1963 and pushed galaxy redshift records to the edge of the observable Universe.

Hysteresis

Hysteresis is the dependence of a material's state on its history, seen when a ferromagnet's magnetization lags the applied field and traces a closed hysteresis loop.

Hysteretic damping

Hysteretic damping, also called structural or loss factor damping, is a damping model in which the damping force is proportional to displacement or strain rather than to velocity.

Hyunjoo Lee

Hyunjoo Lee (이현주) is a South Korean chemist and KAIST Endowed Chair Professor known for shape-controlled platinum and single-atom catalysts for fuel cells, electrolyzers, and exhaust treatment.

Sep 20, 2026

Hyunsoo Yang

Hyunsoo Yang is a spintronics researcher and professor of electrical and computer engineering at the National University of Singapore, known for spin-orbit torques and 2D material spintronics.

HZ 43A

HZ 43A, also cataloged as WD 1314+293, is a hot hydrogen-rich white dwarf about 65 parsecs away, in a binary system with the red dwarf companion HZ 43B.

HZ 44

HZ 44 is a hot subdwarf star of spectral type sdO in Canes Venatici, known for the most completely described chemical composition of any hot subdwarf and used to calibrate astronomical spectrographs.

ʻOumuamua

ʻOumuamua (1I/2017 U1) is the first interstellar object confirmed to pass through the Solar System, discovered in October 2017 by the Pan-STARRS1 telescope in Hawaii as it was leaving.

I Boo

I Boo, also known as 44 Bootis, is a triple star system in the constellation Boötes about 42 light-years away whose fainter pair is a W Ursae Majoris eclipsing binary.

I-adic completion

The I-adic completion of a ring R at an ideal I is the inverse limit of the quotients R/Iⁿ, replacing polynomials by formal power series and yielding the p-adic integers.

Oct 22, 2026

i-PI

i-PI is a Python force engine for molecular simulations, first released in 2014, where a server propagates nuclear dynamics and client codes compute energy, forces, and virial.

Oct 22, 2026

i-process

The i process, or intermediate neutron-capture process, is a nucleosynthesis mechanism that builds heavy elements at neutron densities between those of the s and r processes.

I-SPY 2 trial

The I-SPY 2 trial is an adaptive phase 2 platform trial launched in 2010 testing new drugs added to standard chemotherapy in high-risk stage II or III breast cancer.

I. Bernard Cohen (1914–2003) was an American historian of science at Harvard, the first American to receive a doctorate in the field, who built its history of science department and translated Newton's Principia.

I. Michael Ross

I. Michael Ross (Isaac "Mike" Ross) is an American mathematician at the Naval Postgraduate School known for pseudospectral optimal control theory and the DIDO software.

I² statistic

The I² statistic, also written I-squared, is a measure used in meta-analysis to describe the percentage of variability in effect estimates due to between-study heterogeneity rather than sampling error.

I3S (research laboratory)

i3S, formally the Laboratoire d'Informatique, Signaux et Systèmes de Sophia Antipolis, is a French joint research unit (UMR 7271) in information and communication sciences, created in 1989 and located in Sophia Antipolis near Nice.

IAEA Fusion Energy Conference

The IAEA Fusion Energy Conference (FEC) is the International Atomic Energy Agency's biennial forum for fusion experiments, theory, and technology, first held in Salzburg in 1961.

Iain M. Johnstone

Iain M. Johnstone is an Australian-born mathematical statistician, Marjorie Mhoon Fair Professor at Stanford, known for wavelet shrinkage estimation and the distribution of the largest eigenvalue in PCA.

Sep 20, 2026

Iain McCulloch

Iain McCulloch is an organic semiconductor materials chemist and Fellow of the Royal Society who directs Princeton's Andlinger Center and designs semiconducting polymers like pBTTT.

Iain Stewart (geologist)

Iain Stewart is a British geologist and BBC presenter who holds the chair of geoscience communication at the University of Plymouth, known for documentaries like Earth: The Power of the Planet.

Ian Affleck

Ian Affleck was a Canadian theoretical physicist at the University of British Columbia known for the AKLT model of quantum spin chains and the Affleck-Dine mechanism for baryogenesis.

Ian Agol

Ian Agol is an American mathematician at the University of California, Berkeley, who works on hyperbolic 3-manifolds and won the 2016 Breakthrough Prize in Mathematics.

Ian Axford

Ian Axford (1933–2010) was a New Zealand space physicist who led the Max Planck Institute for Aeronomy and shaped theories of the magnetosphere and cosmic rays.

Ian B. Spielman

Ian B. Spielman (born 1976) is an American atomic physicist at NIST and a Fellow of the Joint Quantum Institute, known for engineering synthetic gauge fields in ultracold atoms.

Ian C. Percival

Ian C. Percival, born 1931, is a British physicist, Fellow of the Royal Society, and emeritus professor at Queen Mary University of London known for his 1973 conjecture on quantum chaos.

Ian Coddington

Ian Coddington is a physicist at NIST in Boulder, Colorado, known as a pioneer of dual-comb spectroscopy, whose open-path laser instruments measure methane and other trace gases for emissions monitoring.

Ian Dell'Antonio

Ian Dell'Antonio is an observational astronomer and Professor of Physics at Brown University who uses weak gravitational lensing to map dark matter and study galaxy clusters.

Ian G. Macdonald

Ian G. Macdonald, also known as Ian Grant Macdonald, was a British pure mathematician, born in 1928 and died in 2023, best known for the Macdonald polynomials.