
All briefs
561 briefs · 6515 min · 193–288 on page 3 of 6

Ivan Pavlov

James Clerk Maxwell

James Lovelock

James Prescott Joule

Jane Goodall

Jean-Baptiste Lamarck

Jean Piaget

Jing Fang

Jocelyn Bell Burnell

PSR B1919+21

Johannes Kepler

John Logie Baird

John Maynard Smith

John Tyndall

John von Neumann

John William Strutt, 3rd Baron Rayleigh

Josef Stefan

Joseph Henry

Joseph-Louis Lagrange

Kamioka Observatory

Karl von Frisch

Katherine Johnson

Kinetic theory of gases
Bernoulli’s 1738 kinetic theory is the first mechanistic explanation of gas behaviour. It correctly identifies pressure as momentum transfer and temperature as mean kinetic energy. It derives Boyle’s law from molecular motion. It fails to resolve energy conservation or collision elasticity — gaps that stalled acceptance for a century. Its value lies not in immediate utility but in framing matter as particulate and dynamic — a conceptual pivot that enabled thermodynamics and statistical mechanics.

Kirchhoff's circuit laws
Kirchhoff’s 1845 circuit laws are two experimentally derived equalities — one for current at junctions, one for voltage around loops — valid only under strict physical assumptions of the lumped-element model.

Knot theory

Konrad Lorenz

Kurt Gödel

Lambda calculus

Conservation of mass

Lawrence Kohlberg

Lee Berger (paleoanthropologist)

Animalcule

Lise Meitner

Liu Hui

Lorentz transformation
Lorentz’s transformations were a technically successful but conceptually constrained response to experimental anomalies in electrodynamics. They preserved the aether while making predictions match observation—by introducing local time, length contraction, and time dilation as mathematical corrections. Their algebraic form survived into special relativity, but their physical meaning did not.

Louis Leakey

Louis Pasteur

Australopithecus afarensis

Lucy (hominid)

Ludwig Boltzmann

Lynn Margulis

Lysosome

Insular biogeography

Magnetic resonance imaging

Magnetostratigraphy

Plasmodium

Manganese nodule

Margaret Mead

Marie Curie

Mario Molina

Marvin Harris

Mary Anning

Max Planck

Maxwell's equations

Meave Leakey

Nuclear fission

Melatonin

Metamaterial

Michael Faraday

Milgram experiment

Oil drop experiment

Mitchell Feigenbaum

Mitochondria

Molecular clock

Nash equilibrium

Nasir al-Din al-Tusi

Natural killer cell

Neurotransmitter

Solar neutrino problem

Massively parallel sequencing

Nicolaus Copernicus

Niels Bohr

Nikola Tesla

Niles Eldredge

Nitrogen fixation

Noether's theorem
Noether's theorem is the rigorous, general proof that continuous symmetries of the action imply conservation laws. It was published in 1918 in Invariante Variationsprobleme. It applies only to smooth, differentiable symmetries in conservative systems. It resolved energy conservation in general relativity. It reshaped theoretical physics’ emphasis toward symmetry.

Non-Euclidean geometry

Norbert Wiener

Norman Borlaug

Nylon

Ocean acidification

Thermohaline circulation

Ohm's law

Ole Rømer

Oliver Heaviside

Omar Khayyam

Combined oral contraceptive pill

Othniel Charles Marsh

Ozone depletion

Palynology

Swan neck flask

Henry Molaison

Paul Dirac

History of penicillin
