Three Centuries of Discovery
342 events ImmersiveEquations- c. 300 BC
Euclidproves there are infinitely many primes — Elements IX.20, the oldest proof still taught unchanged
- c. 300 BC
Euclidthe greatest-common-divisor algorithm — Elements VII.2, subtract the smaller from the larger and repeat; run against 1 it writes any number’s continued fraction, the oldest algorithm still in daily use
- c. 240 BC
Eratosthenesthe sieve — strike out the multiples of each prime in turn and the survivors are the primes; the algorithm this instrument still runs
- c. 480
Zu Chongzhifinds 密率 355/113 — π to seven digits from a three-digit denominator, the luckiest fraction in the catalogue, unbeaten for nine hundred years
- 984
Ibn SahlOn Burning Mirrors and Lenses states the refraction ratio geometrically — the law later called Snell’s, six centuries early
- 1602
Galileotimes swinging lamps against his own pulse and declares the pendulum isochronous — the swing takes the same time whatever its width. The observation that would define the second, and (for wide swings) a lie
- 1621
Snellrediscovers the sine law of refraction n₁ sin θ₁ = n₂ sin θ₂ (published by Descartes 1637); the empirical bend the principle of least time must explain
- 1656
Huygenshangs Galileo’s pendulum inside a clock — timekeeping error collapses from a quarter-hour a day to seconds, and for the next 271 years the pendulum is how civilisation knows what time it is
- 1659
Huygensproves the cycloid is the tautochrone — a bead released anywhere on it reaches the bottom in the same time — and hangs a pendulum from cycloidal cheeks to keep true time
- 1662
Fermatderives Snell’s law from a deeper premise — light takes the path of least time — the first physical law stated as a minimum principle
- 1665
Huygenstwo pendulum clocks on one beam fall into step — synchrony, first noticed
- 1669
Newton · Raphsonroot-finding by sliding down the tangent — De analysi’s iteration, simplified by Raphson in 1690 into the z − f/f′ update still running inside every solver
- 1669
Huygenssettles the laws of elastic collision for the Royal Society (beside Wallis and Wren) — momentum and live force both conserved, the update every clack still obeys
- 1687
Newtonuniversal gravitation — and the two-body ellipse, solved exactly
- 1690
HuygensTraité de la Lumière: each wavefront point is a source of secondary wavelets — refraction as the geometry of slower wavefronts, the wave companion to Fermat’s ray
- 1696
Joh. Bernoulliposes the brachistochrone as a public challenge and solves it by an optical analogy; Newton, Leibniz, l’Hôpital and Jakob Bernoulli answer — the curve of fastest descent is a cycloid
- 1733
de Moivrethe first normal curve, as the limit of many coin flips
- 1736
Eulersettles the seven bridges of Königsberg by refusing to enumerate routes — a walk crossing every bridge once needs zero or two land masses of odd degree, and the city has four; the paper that founds graph theory by weighing the shores instead
- 1737
Eulerwrites ζ(s) as a product over primes, and from Σ 1/p diverging gives a new proof they never run out
- 1738
D. Bernoulliresolves the St. Petersburg paradox by proposing that people maximise expected utility, not expected money, with utility growing like the logarithm of wealth — the seed of growth-optimal betting
- 1744
Maupertuisproposes the principle of least action — nature is thrifty with a quantity ∫ p dq — generalising Fermat’s least time from light to matter
- 1744
EulerMethodus inveniendi founds the calculus of variations and gives the equation an extremal curve must satisfy — the tool that turns “least time/action” into a solvable equation
- 1747
d'Alembertsolves the vibrating-string wave equation
- 1750
Eulercounts vertices, edges and faces of solids in a letter to Goldbach — V − E + F = 2, the number a surface conserves no matter how a drawing on it struggles
- 1760
Bernoullithe first mathematical epidemic model — weighing smallpox inoculation against the disease
- 1763
Bayesbelief updates as posterior ∝ likelihood × prior — the rule the filter runs
- 1765
Eulerthe equations of torque-free rotation — Theoria motus corporum solidorum, the principal axes and their moments
- 1772
Lagrangethe equilateral three-body solution and the L-points
- 1787
Chladnibows a sand-strewn metal plate and the grains leap off the moving regions to settle on the still nodal lines — the first images of a vibration’s modes
- 1788
LagrangeMécanique analytique recasts all of mechanics from L = T − V and δ∫L dt = 0 — no forces, no diagrams, one variational principle and the Euler–Lagrange equations
- 1796
Gauss & Legendreconjecture the prime count grows like x / ln x — Gauss noticed it at fifteen, Legendre put it in print
- 1801
Youngthe original two-slit experiment — light interferes, so light is a wave
- 1809
Gaussleast squares to track Ceres from a few noisy sightings — estimation is born
- 1810
Laplacethe Central Limit Theorem in its general form
- 1812
Gausswrites Laplace that he knows the invariant measure of the continued-fraction map — the statistics every number’s digits obey, stated a century before ergodic theory existed to prove it
- 1813
Ponceletthe closure theorem, drafted as a prisoner of war at Saratov — if one orbit riding a caustic closes after n bounces, every orbit on that caustic closes in n
- 1815
Cauchyfounds the calculus of permutations: every shuffle is even or odd and no sequence of swaps can change which — the coin the fifteen puzzle will be flipping seventy years later
- 1822
Fourierclaims any periodic signal is a sum of sines (Théorie analytique de la chaleur)
- 1822
Navierwrites the momentum equation — viscosity and all
- 1831
Faradaydiscovers induction and thinks in lines of force — the first picture of a field filling space, not action at a distance
- 1833
Gausswrites down the linking integral — a number, computed from two curves, that counts how many times they wind through one another; topology’s first invariant, and the count that makes any two Hopf fibres inseparable
- 1834
Scott Russellobserves a solitary wave of translation on the Union Canal near Edinburgh — a heap of water that travels a mile without changing shape
- 1834
W. R. Hamiltonstates the principle of stationary action δS = 0 in its modern form, unifying optics and mechanics under one geometry of extremal paths
- 1834
Poinsotthe geometric picture — the inertia ellipsoid rolling on a fixed plane, tracing the polhode and herpolhode
- 1845
Stokesputs it on rigorous footing: the modern Navier–Stokes form
- 1847
Cauchymethod of steepest descent — follow the negative gradient downhill, the optimiser still in use
- 1848
Wilbrahamfirst spots the overshoot at a jump — then it is forgotten for fifty years
- 1848
Villarceaushows a torus sliced on the right diagonal cuts in perfect circles — the two hidden circles through every point of a ring that the Hopf fibres turn out to trace
- 1850
Dirichletstudying quadratic forms, partitions the plane into regions of nearest lattice point — the first “Dirichlet tessellation”, the idea later named after Voronoi
- 1852
Schläfliclassifies the regular polytopes in every dimension — exactly six in 4-D, only three in each dimension above — decades before anyone could draw one
- 1859
DarwinOn the Origin of Species: heritable variation plus differential survival is enough to build endless complexity with no designer — the algorithm before anyone called it one
- 1859
Riemannextends ζ to the complex plane and ties π(x) exactly to its zeros — the explicit formula, and the Hypothesis still open
- 1865
Clausiusnames entropy and states the second law of thermodynamics
- 1865
Maxwellunifies electricity, magnetism and light into one set of field equations — and predicts electromagnetic waves at speed c
- 1867
Maxwellproposes a tiny "demon" that sorts fast from slow molecules — apparently defeating the second law without doing work
- 1867
Kelvinproposes atoms are knotted vortex rings in the ether — wrong physics, but it launches the mathematical study of knots
- 1872
Boltzmannthe H-theorem and S = k ln Ω — irreversibility from counting
- 1873
Hierholzerproves the converse Euler left open: a connected graph with zero or two odd vertices always has an Eulerian trail, built by splicing closed detours — so fixing the parity genuinely opens the walk
- 1876
Loschmidtthe reversibility objection: symmetric laws, an asymmetric world
- 1877
Taitbegins tabulating knots by crossing number — the first knot tables, and the conjectures that drove the field for a century
- 1879
Cayleyasks which starting points Newton’s method sends to which root — solves the quadratic (a straight border), admits the cubic “presents considerable difficulty”, and stops
- 1879
Johnson & Storyprove in the American Journal of Mathematics that sliding reaches exactly half of all deals — the even half; the 14-15 swap lives on the other island, unreachable by any path
- 1880
Stringhamfirst publishes pictures of the regular 4-polytopes, projected to the page — the figures that made the fourth dimension something you could see
- 1883
Reynoldshis number, and the dye experiment that catches laminar flow breaking up
- 1887
Michelson–Morleyfind no aether — light's speed refuses to add up
- 1888
Hintoncoins the word "tesseract" for the 4-cube and popularises seeing the fourth dimension through its 3-D shadows and cross-sections
- 1890
Poincaréno closed form for three bodies — the first sight of chaos
- 1890
Poincarérecurrence: a closed system must eventually return near its start
- 1891
Hurwitzevery irrational is approached within 1/(√5·q²) by infinitely many fractions p/q — and √5 is sharp, because the golden ratio can be served no better: the worst-approximable number, identified and convicted
- c. 1891
Loydclaims the fifteen-puzzle craze and hangs $1000 on the 14-15 swap — a prize designed to be safe, twelve years after the proof that it could never be paid
- 1892
Lyapunovhis stability theory gives the exponent λ that measures the stretch
- 1895
Korteweg & de Vriesderive the KdV equation for shallow water waves and find its exact soliton solution, vindicating Scott Russell 60 years later
- 1895
Lorentzthe force on a moving charge, F = q(E + v×B) — the law that bends every trajectory in this instrument
- 1896
Hadamard & de la Vallée Poussinindependently prove the Prime Number Theorem, from ζ having no zeros on the line Re(s) = 1
- 1897
Paretomeasures incomes across Europe and finds the same heavy power-law tail everywhere — the 80/20 law, the first quantitative law of inequality
- 1899
Gibbsexplains it: the ripple narrows but homes in on ≈8.95%, never vanishing
- 1900
Bacheliermodels market prices as a random walk — finance meets diffusion, the first time-series
- 1904
von Kochdraws the Koch curve — a continuous line with no tangent anywhere, built by one recursive rule that replaces each segment with four — an early fractal decades before the word existed
- 1905
EinsteinBrownian motion ties the walk to atoms and Avogadro's number
- 1905
Einsteinspecial relativity: c is invariant, and space and time mix
- 1906
Markovthe Markov chain — a process whose next step depends only on the present, with a long-run equilibrium
- 1908
Minkowskispacetime — the geometry in which the light cone is absolute
- 1908
Langevinthe Langevin equation — Newton plus a random force; the stochastic differential equation that underlies every diffusion here
- 1908
Voronoigeneralises the nearest-point partition to any dimension and gives it rigour; the cells now carry his name and turn up across physics, biology and computer science
- 1909
Haarthe first wavelet — a square step that splits a signal by scale
- 1911
WeylWeyl’s law — the count of eigenfrequencies below a bound grows with the drum’s area, so the spectrum does betray the size, if not the shape
- 1912
Perron & Frobeniusa positive matrix has one largest eigenvalue with an all-positive eigenvector — the unique, well-defined rank
- 1912
Smoluchowskithe one-way-valve gedankenexperiment — a passive trapdoor cannot rectify thermal fluctuations into work, because at one temperature the door jiggles exactly as hard as the molecules it is meant to sort
- 1913
Bohrquantises the hydrogen atom — electrons sit on fixed energy rungs E_n = −13.6 eV/n², explaining its spectral lines a decade before wave mechanics justified the ladder
- 1913
Dudeneyprints gas–water–electricity in The Strand Magazine, calling the puzzle "as old as the hills" — three houses, three utilities, nine wires, no crossings; already known to have no answer
- 1915
Einsteingeneral relativity: matter curves spacetime, and light follows the curve
- 1915
Whittakerthe interpolation formula that rebuilds a signal from its samples
- 1916
Schwarzschildthe first exact solution — and with it, the event horizon
- 1918
Julia & Fatouthe dynamics of z² + c — decades before anyone could see it
- 1919
Eddingtonthe eclipse measures the bending at twice Newton's value — Einstein, famous overnight
- 1924
Bosenew statistics for light quanta — particles that bunch together
- 1924
de Brogliematter has a wavelength too — so particles can interfere
- 1925
Einsteinextends Bose statistics to atoms and predicts the condensate
- 1925
Isingsolves the 1D chain — and finds no phase transition (the model nearly dies here)
- 1925
Lotkaderives the oscillating predator–prey equations in Elements of Physical Biology — a population read as a chemical-style dynamical system
- 1925
Yulea growth process for biological genera in which the already-large grow fastest — the first “rich get richer” mechanism behind a power law
- 1926
Schrödingerthe wave equation — the whole future of ψ
- 1926
Born|ψ|² is probability: the cloud itself (Nobel 1954)
- 1926
Volterraexplains why the WWI pause in Adriatic fishing raised the shark fraction — the same equations, from his son-in-law fish-market data
- 1927
Hundfirst spots tunnelling, in the splitting of molecular spectra
- 1927
Madelungrewrites ψ as a fluid — a density and a flowing phase
- 1927
Kermack & McKendrickthe SIR model and the epidemic threshold: an outbreak needs R₀ > 1 to take off
- 1927
Reidemeisterproves that any two diagrams of the same knot differ by three local moves — so a knot invariant is anything those moves leave unchanged
- 1927
Birkhoffmakes the billiard the model dynamical system — the flight between walls compressed into the area-preserving bounce map (s, sin θ), the whole table read two numbers at a time
- 1928
Gamowexplains alpha decay by tunnelling — radioactivity as a quantum leak
- 1928
Nyquistfixes the rate: sample above twice the top frequency
- 1929
Hubblegalaxies recede at a speed proportional to their distance — the universe is expanding
- 1929
Szilárdresolves the demon with a one-molecule engine: one measurement yields kT ln 2 of work — and costs one bit of memory
- 1930
Kuratowskicharacterizes every graph that can be drawn flat: planar exactly when it hides no K₅ and no K₃,₃ — the utilities board convicted by name, and made one of only two minimal culprits
- 1931
Gibratthe law of proportionate effect — sizes that grow by random percentages drift into a log-normal spread, an early mechanism for the fat tail
- 1931
Hopffibres the 3-sphere into linked circles, one over each point of the 2-sphere — the first map proven impossible to unwind (π₃(S²) ≠ 0), and the shape hiding under every qubit
- 1933
Kotelnikovproves the sampling theorem in full
- 1933
Zwickythe Coma cluster moves far too fast for its visible mass — most of the gravitating matter is unseen
- 1933
Thompsonthe first bandit algorithm — to choose between two medical treatments, draw each one’s success rate from its Bayesian posterior and play the winner; posterior sampling, forgotten for sixty years then found to be near-optimal
- 1934
Gausetests predator–prey in test tubes of Paramecium and Didinium — the predator eats all prey then starves; coexistence needs a refuge
- 1934
Delaunaydefines the dual triangulation — connect seeds whose cells touch — that maximises the smallest angle and avoids thin slivers, the default mesh of computational geometry
- 1935
Einstein, Podolsky & Rosenargue QM must be incomplete — "spooky action at a distance" can't be real
- 1935
Greenshieldsmeasures the first speed–density relation from photographs of real traffic — the fundamental diagram, where flow rises, peaks at a critical density, then falls as the road clogs
- 1936
Whitneythe embedding theorem — any smooth d-manifold sits faithfully inside ℝ^(2d+1)
- 1936
Churchdefines the λ-calculus and shows it captures all effective computation — the same class Turing’s machine reaches, the two halves of the Church–Turing thesis
- 1936
TuringOn Computable Numbers defines the machine, builds a universal one that runs any other, and proves the halting problem has no algorithm — the birth of computer science
- 1937
Landauthe general theory of phase transitions and the order parameter
- 1938
Londonties superfluid helium to Bose–Einstein condensation
- 1942
Alfvénmagnetohydrodynamics and the guiding-centre drift — why a plasma follows field lines and slips sideways as E×B (Nobel 1970)
- 1944
Onsagersolves the 2D Ising model exactly — T_c and the critical exponents, by hand
- 1944
Gutenberg & Richterearthquake magnitudes follow a power law — no characteristic size, decades before anyone could say why
- 1944
Itôstochastic calculus: the lemma that integrates dS exactly into a log-normal
- 1944
von Neumann & MorgensternTheory of Games and Economic Behavior founds game theory — rational players, payoff matrices and the minimax theorem
- 1946
Gabortiles time–frequency into "logons" and finds the joint-resolution limit
- 1946
Blochintroduces the Bloch vector for nuclear magnetic resonance — the unit sphere it sweeps out becomes, decades later, the geometry of every single qubit
- 1946
Blackposes the mutilated chessboard in Critical Thinking — cut two opposite corners and no thirty-one dominoes can tile the sixty-two squares, because every domino covers one black and one white and the lost corners share a colour
- 1948
Shannon'A Mathematical Theory of Communication' — entropy, capacity, the whole field
- 1948
von Neumann & Ulaminvent cellular automata — a self-reproducing machine on a grid
- 1948
Coxeterpublishes Regular Polytopes — the modern synthesis of Schläfli symbols, reflection groups and projections the field still works from
- 1948
Feynmanrecasts quantum mechanics as a sum over all paths weighted by e^(iS/ℏ) — and shows the classical least-action path is simply where the phases stop cancelling
- 1949
Onsagercirculation is quantised: vortices carry integer charge
- 1949
Shannonmakes the sampling theorem a cornerstone of digital signal processing
- 1949
Ulam · Metropolisthe Monte Carlo method — answer by sampling when the formula is hard
- 1949
Hebb'neurons that fire together wire together' — memory as the strengthening of a connection
- 1949
Floodposes the “fiancée problem” — choosing when to stop among candidates seen one at a time in random order; the first statement of what would become the secretary problem, from a co-author of the Prisoner’s Dilemma
- 1950
Hammingthe first error-correcting code — parity that names the flipped bit
- 1950
Nashthe Nash equilibrium — every finite game has a stable strategy profile no player can beat by deviating alone
- 1951
Belousovdiscovers a chemical reaction that oscillates in colour instead of settling to equilibrium — rejected as impossible by the journals, and ignored for a decade
- 1952
Turing'The Chemical Basis of Morphogenesis' — diffusion can make pattern, not just smooth it
- 1952
RobbinsSome aspects of the sequential design of experiments — names and formalises the multi-armed bandit, the clean statement of the explore-versus-exploit dilemma
- 1953
Metropolis, Rosenbluth & Tellerthe Metropolis algorithm — sample a Boltzmann distribution by accepting moves with probability min(1, e^−ΔE/T)
- 1954–63
Kolmogorov, Arnold & Moserthe KAM theorem — under a small perturbation the invariant tori that survive are exactly the ones whose winding numbers are hardest to approximate by rationals: order persists where arithmetic is worst
- 1955–56
Lighthill, Whitham & Richardsmodel traffic as a compressible fluid: density obeys a conservation law, and a jam is a shock wave — a moving discontinuity that travels backward through the stream of cars
- 1956
KellyA New Interpretation of Information Rate — a gambler with a private wire should stake the fraction of his bankroll that maximises expected log-wealth, and his growth rate then equals the Shannon capacity of the channel
- 1957
Esakithe tunnel diode puts the effect to work (Nobel 1973)
- 1957
Broadbent & Hammersleyfounding paper on percolation — originally motivated by fluid flow through random media
- 1957
Bellmandynamic programming and the principle of optimality — the value of a state is its best reward plus the discounted value of where you land; also names the curse of dimensionality
- 1958
Rosenblattthe perceptron: a learning machine of weighted neurons — but a single layer cannot solve XOR
- 1959
Hollingthe functional response — a predator saturates because prey take time to handle (type II); the realism that lets the model cycle and crash
- 1959
Erdős & Rényithe theory of random graphs — wire N nodes with independent edges and a giant component snaps in abruptly; the null model every real network is measured against
- 1960
Reed & Solomoncodes that armour CDs, QR codes and deep-space links
- 1960
Kalmanthe recursive filter: optimal estimation of a linear system, one step at a time
- 1960
Gardnerpopularises the puzzle as the “sultan’s dowry” / secretary problem in Scientific American, and the surprising 1/e answer reaches a wide audience
- 1961
Jönssonruns the double slit with single electrons, one at a time
- 1961
Landauershows that erasing one bit of information dissipates at least kT ln 2 as heat — information is physical
- 1961
FitzHugh & Nagumoreduce the Hodgkin–Huxley nerve impulse to two variables — a fast excitable voltage and a slow recovery — the minimal model of a firing, refractory medium
- 1961
Wangproposes edge-matching tiles and conjectures that any set able to tile the plane can also tile it periodically — turning geometry into a decision problem
- 1961
Breimanproves the log-optimal (Kelly) strategy is asymptotically best two ways at once — it maximises the long-run growth rate and minimises the expected time to reach any wealth goal, almost surely beating every other rule
- 1961
Lindleygives the dynamic-programming solution — reject a fixed early block, then take the first candidate better than all before it — and shows the optimal cutoff is the fraction 1/e
- 1962
Radóintroduces the busy beaver game — a perfectly well-defined function that no program can compute, the halting problem wearing a number
- 1962
ThorpBeat the Dealer — takes Kelly from card-counting blackjack to Wall Street, running the first quantitative hedge fund on the growth-optimal bet; the criterion crosses from the casino to the market
- 1963
Lorenzthree equations for convection — the butterfly effect, chaos found by accident from a rounded printout
- 1963
Rosenzweig & MacArthura graphical predator–prey model with logistic prey and saturating predation — isoclines that predict a stable point or a limit cycle
- 1963
Ulamdoodling through a dull talk, coils the integers on a grid and the primes fall onto unmistakable diagonal lines
- 1963
Dynkinsets optimal stopping on rigorous ground as a theory of Markov processes, proving the secretary problem’s cutoff fraction and win probability both tend to exactly 1/e as the field grows
- 1963
Feynmanthe ratchet-and-pawl lecture — works Smoluchowski’s verdict to the numbers: in a single heat bath the pawl bounces just often enough to undo its own rectifying, and the wheel only turns when two temperatures differ
- 1964
Sharkovskiiorders the periods: a map with a 3-cycle must have cycles of every length
- 1964
Bellturns "is the world local?" into an inequality you can actually measure
- 1964
Zhabotinskyrevives Belousov’s reaction and finds it makes travelling and rotating waves in a dish — chemistry that propagates like a nerve impulse or a heartbeat
- 1964
McCarthyfiles the mutilated chessboard as a "tough nut" for automated reasoning — a proof a child finds by counting colours that a resolution prover grinds at exponentially; the cycle’s wink across at the halting wall
- 1965
Penrosecollapse to a singularity is inevitable — black holes are a robust prediction of relativity, not a fluke (Nobel 2020)
- 1965
Cooley & Tukeythe FFT makes the transform cheap — now inside MP3, JPEG, every analyser
- 1960s
Kirkpatrick et al.Monte Carlo computation of p_c for the square lattice ≈ 0.5927
- 1965
Samuelsongeometric (not arithmetic) Brownian motion for prices — they can never go negative
- 1965
Zabusky & Kruskalrediscover solitons on a computer, observe that two pulses pass through each other unchanged — and coin the name "soliton"
- 1966
Kac“Can one hear the shape of a drum?” — asks whether two differently-shaped membranes could ever share an identical spectrum of tones
- 1966
Bergerdisproves Wang — the domino problem is undecidable — and in the proof exhibits the first aperiodic tile set: 20,426 tiles that cover the plane but never repeat
- 1967
Winfreebiological oscillators sync once the coupling beats the spread
- 1967
Mandelbrot'How Long Is the Coast of Britain?' — fractional dimension enters science: the length depends on the ruler
- 1967
Viterbithe Viterbi algorithm — dynamic programming recovers the single most-likely hidden path through a noisy sequence, exactly, in one backward sweep
- 1968
Venezianohis amplitude for the strong force secretly describes a string
- 1968
Lindenmayera botanist invents L-systems to model how plants develop: a grammar that rewrites every symbol in parallel each step, so a one-line rule grows into a branching organism
- 1968
Arnold & Avezstretches a picture of a cat over the torus as the model chaotic map — area exactly preserved, every detail shredded along the golden-ratio directions
- 1969
Clauser, Horne, Shimony & Holtthe experimentally testable form of Bell's bound, S ≤ 2
- 1969
Apollothe Kalman filter flies the guidance computer to the Moon and back
- 1969
Chirikovdistills every kicked rotor into one area-preserving map and one knob k — the standard map, chaos’s hydrogen atom, with a resonance-overlap criterion for when the last order breaks
- 1970
Nambu, Nielsen & Susskindread it literally: the constituents are vibrating strings
- 1970
Conwaythe Game of Life makes cellular automata famous
- 1970
Gosperfinds the glider gun — Life grows without bound, so it can store and move information
- 1970
Zel'dovichthe approximation that lets gravity be run by hand — matter collapses first into sheets (pancakes), then filaments, then knots
- 1970
Baum, Petrie, Soules & Weissthe hidden Markov model with forward–backward and Baum–Welch — infer the hidden states, and the chain itself, from the observations alone
- 1970
Sinaiproves the dispersing billiard — a square with a disc cut out — is ergodic and hyperbolic: the first mechanical system where Boltzmann’s ergodic hypothesis actually holds
- 1971
Wilsonthe renormalisation group explains universality (Nobel 1982)
- 1971
Hafele–Keatingflying atomic clocks confirm time dilation directly
- 1971
Rosenzweigthe paradox of enrichment — raising the prey carrying capacity destabilises the equilibrium into ever-wider cycles that can drive extinction
- 1971
Sakodathe checkerboard model of social interaction — agents on a grid move by attraction and aversion, the first cellular model of self-sorting
- 1971
SchellingDynamic Models of Segregation — a mild preference not to be a small local minority tips a mixed city into near-total segregation; micromotives ≠ macrobehavior
- 1972
Gierer & Meinhardtname the design rule: short-range activation, long-range inhibition
- 1972
Mayasks whether a large complex system is stable and finds it usually is not — richly connected ecosystems tend to be less stable, not more
- 1972
Winfreeshows the rotating chemical spiral turns about a phase singularity — a point where phase is undefined — and ties the same geometry to cardiac fibrillation
- 1973
Black · Scholes · Mertonthe same log-normal, priced: option value as a discounted forecast
- 1973
Maynard Smith & Pricethe evolutionarily stable strategy — game theory carried into biology, where fitness rather than reason selects the move
- 1973
Rechenbergevolution strategies: mutate and select real-valued design parameters to optimise wings and nozzles in a wind tunnel — the parallel European root of evolutionary computation
- c. 1973
Gomoryremoves any one black and any one white square and shows a domino tiling always survives — the board’s Hamiltonian rook circuit splits into two even arcs, each trivially tiled; the exact door to Black’s wall
- 1974
Littlecasts a neural network as a spin system — persistent firing states are the stored memories
- 1974
Penrosefinds an aperiodic set of just two tiles — kite and dart — with five-fold symmetry and golden-ratio statistics, beauty falling out of impossibility
- 1974
Bunimovichthe stadium — chaos out of focusing walls: pull a circle apart by any nonzero amount, splice in two straight edges, and the billiard turns fully chaotic
- 1975
Li & Yorkecoin the word — “Period Three Implies Chaos”
- 1975
Kuramotothe exactly solvable synchronization model — order parameter r and the critical K_c
- 1975
HollandAdaptation in Natural and Artificial Systems formalises the genetic algorithm — selection, crossover and mutation on bit-strings — and proves the schema theorem that says why it works
- 1976
Robert Maythe logistic map as a toy ecology (Nature) — a simple law, an uncomputable fate
- 1976
Pricecumulative advantage in citation networks — papers are cited in proportion to the citations they already have, deriving the power-law tail decades before it was rediscovered
- 1978
Feigenbaumfinds the doubling ratio δ ≈ 4.6692 is universal — on a pocket calculator
- 1978
Granovetterthreshold models of collective behavior — each person acts once enough others have, so a crowd tips on the distribution of thresholds, not the average
- 1979
Kaplan–Yorkeconjecture links the Lyapunov exponents to the attractor's fractal dimension
- 1979
Gittinscollapses the intractable Bayesian bandit to a single number per arm — the Gittins index — and playing the highest index is exactly optimal; a landmark that was optimal but too costly to compute in practice
- 1979
Greeneprices the death of the standard map’s last invariant circle: the golden torus breaks at k ≈ 0.971635, located by watching the residues of its Fibonacci-convergent orbits cross ¼
- 1980
Benettinan algorithm to measure λ from a shadow orbit — the method the rack uses live
- 1980
Tsirelsonproves quantum mechanics can violate CHSH only up to 2√2
- 1980
Mandelbrotcomputes the set at IBM and reveals the shape
- 1980
Peeblesthe gravitational theory of how faint early-universe ripples grow into the cosmic web (Nobel 2019)
- 1980
Packard, Crutchfield, Farmer & Shaw“Geometry from a Time Series” — reconstruct an attractor from a single signal’s own delayed copies
- 1980
Benioffbuilds the first quantum-mechanical model of a Turing machine, showing computation can run on quantum hardware — the field’s opening move
- 1981
Binnig & Rohrerthe scanning tunnelling microscope feels single atoms (Nobel 1986)
- 1981
Witten & Sanderdiffusion-limited aggregation — random walkers stick on contact into a branching fractal of dimension ≈ 1.71
- 1981
Takensproves it: delay-coordinate embedding is generically diffeomorphic to the true attractor — same invariants
- 1981
Axelrod & Hamiltonthe iterated tournament — Tit-for-Tat beats every cleverer rule; cooperation evolves among selfish agents that meet again
- 1981
Benzi, Sutera & Vulpianiintroduce stochastic resonance to explain the 100,000-year ice-age cycle: orbital forcing alone is too weak — noise from climate fluctuations makes it detectable
- 1982
Sparrowthe definitive study of the Lorenz equations
- 1982
Aspectswitches the analysers in flight — closes the locality loophole, S ≈ 2.7
- 1982
Nienhuisexact critical exponents β = 5/36, ν = 4/3 via Coulomb gas / conformal field theory
- 1982
Hopfielda recurrent net whose energy only falls, so memories are the basins of attraction it rolls into
- 1982
Berlekamp, Conway & Guy'Winning Ways' proves Life is Turing-complete — a universal computer built from one rule
- 1982
Douady & Hubbardprove M is connected, and give it his name
- 1982
Bennettproves the demon cannot violate the second law: the erasure of its memory ledger, not the measurement, is the thermodynamic cost
- 1982
Andersonthe reverse-time SDE — a diffusion run backward is itself a diffusion, driven by the score of the density; the theorem generative models would later stand on
- 1957 / 1982
Lloydhis 1957 least-squares quantization method, finally published in 1982, iterates seed → cell centroid to minimise error — the algorithm behind centroidal Voronoi tessellations and k-means
- 1982
Shechtmandiscovers quasicrystals — real matter with Penrose-like aperiodic order and forbidden symmetry, ridiculed for years, then the Nobel in Chemistry, 2011
- 1982
Feynman“Simulating Physics with Computers” — argues no classical machine can efficiently simulate quantum systems, and proposes a computer built of quantum parts to do it
- 1983
Gray & Scottthe autocatalytic reaction–diffusion model this engine runs
- 1983
Wolframsorts the 256 elementary rules into four behaviours
- 1983
Grassberger & Procacciathe correlation dimension — read a strange attractor’s fractal dimension straight off the reconstructed cloud
- 1983
Kirkpatrick, Gelatt & VecchiOptimization by Simulated Annealing — melt a hard problem, then cool it slowly through Metropolis moves into its best state
- 1984
Morlet & Grossmannformalise the continuous wavelet transform, out of seismic traces
- 1984
Brady & Ballcopper electrodeposits grow as DLA fractals — the model caught in the lab, the same dimension measured in metal
- 1984
Jonesdiscovers a new knot polynomial out of operator algebras — distinguishing knots that had resisted for decades (Fields Medal 1990)
- 1985
Amit, Gutfreund & Sompolinskythe spin-glass calculation: the net stores ≈0.138N patterns before the basins dissolve
- 1985
Černýindependently applies thermodynamic annealing to the travelling-salesman problem — the method arrives twice at once
- 1985
Deutschdefines the universal quantum computer and the quantum Turing machine, and gives the first problem a quantum computer answers in fewer queries than any classical one
- 1985
Dzhanibekova cosmonaut spins a wing-nut off a bolt aboard Salyut-7 and films it flipping end over end, unbidden, in free fall
- 1985
Lai & Robbinsproves the hard floor — no policy can do better than regret growing as the logarithm of time, and gives index rules that achieve it; the benchmark every bandit algorithm is now measured against
- 1986
Rumelhart, Hinton & Williamsbackpropagation trains hidden layers efficiently — the multilayer network finally learns
- 1986
ReynoldsBoids: three local rules — align, cohere, separate
- 1986
Langtondescribes the ant: a two-rule automaton that wanders chaotically for about ten thousand steps and then, unbidden, builds a periodic “highway” and follows it forever
- 1987
Bak, Tang & Wiesenfeldself-organized criticality: a sandpile tunes itself to the critical point and emits 1/f noise — no parameter set by hand
- 1988
Daubechiescompactly-supported orthonormal wavelets — the basis inside JPEG 2000
- 1988
Suttontemporal-difference learning — update a prediction from a later, better prediction, with no model of the world; the bracket that becomes Q-learning
- 1989
Laskarthe inner Solar System is chaotic, with a ~5-million-year horizon
- 1989
Mallatmultiresolution analysis + the fast wavelet transform
- 1989
Hart, Sandin & Kauffmandistance-estimated ray tracing — march a ray by a safe lower bound on the distance to the surface, which is what makes a 3D escape-time fractal renderable at all
- 1989
WatkinsQ-learning — a model-free, off-policy rule that provably converges to the optimal action-values just by trying, watching and updating
- 1989
Hamiltonthe Markov-switching model carries hidden-state inference into economics — reading booms and recessions as latent regimes behind the noise of GDP and returns
- 1989
GoldbergGenetic Algorithms in Search, Optimization, and Machine Learning carries the method out of Holland’s lab into mainstream engineering and optimization
- 1990
De Kepperfirst chemical Turing patterns seen in the lab (the CIMA reaction)
- 1990
Dharthe abelian sandpile: topplings commute, the recurrent states form a group, and the identity is a fractal
- 1990
Prusinkiewicz & LindenmayerThe Algorithmic Beauty of Plants gives L-systems a turtle to draw with, plus brackets, randomness and parameters — and lifelike ferns, trees and flowers fall straight out of the strings
- 1991
Shishikuraproves the Mandelbrot boundary has Hausdorff dimension 2
- 1991
Ashbaugh, Chicone & Cushmana rigorous account of the half-turn — the “tennis-racket theorem”, why the middle-axis flip is exactly periodic
- 1992
Nowak & Mayspatial games — cooperators and defectors on a grid form ever-shifting fractal patterns; structure alone sustains cooperation
- 1992
TesauroTD-Gammon reaches near-expert backgammon by playing millions of games against itself — temporal-difference learning, scaled up, beats hand-tuned programs
- 1992
Gordon, Webb & Wolpertanswers Kac — no: they build two different polygonal drums with exactly the same spectrum. You can hear the area and perimeter, but not the shape
- 1992
Nagel & Schreckenbergreduce traffic to four cellular-automaton rules — accelerate, brake, dawdle, move — and a phantom jam condenses out of nothing above a critical density, with no accident or bottleneck to cause it
- 1992
Bunimovich & Troubetzkoyprove the ant’s path is always unbounded from any finite start — so the highway must eventually emerge, though no shortcut says when
- 1992
Deutsch & Jozsaturn that into the first exponential separation — decide in a single query whether a function is constant or balanced, where every classical method needs many
- 1992
Dyson & Falkthe period of the discrete cat map — a scrambled N-pixel picture must return exactly, in at most 3N steps, on a schedule no smooth formula predicts
- 1992
Shinbrot, Grebogi, Wisdom & Yorkerun a real double pendulum on a bench and measure its trajectories diverging at λ ≈ 7.5 s⁻¹ — the textbook clock, hinged once more, certified chaotic in the laboratory
- 1992
Ajdari & Prostthe flashing ratchet — switch an asymmetric sawtooth potential on and off and diffusing particles are pumped one way with no net force applied: a rectified fluctuation, running as a machine
- 1993
Berrouturbo codes reach within a whisker of the Shannon limit
- 1994
Watts & Strogatz · Barabásipercolation transitions in real-world networks: internet, epidemics, markets
- 1994
Moss, Pierson & O'Gormandemonstrate stochastic resonance in biological neurons — sensory systems appear to operate near the optimal noise level for signal detection
- 1994
Shorfinds a quantum algorithm that factors large integers in polynomial time — breaking RSA in principle and turning a curiosity into a field with stakes
- 1995
Englert–Greenberger–Yasinpin down the exact duality relation V² + D² ≤ 1
- 1995
Cornell, Wieman & Ketterlethe first gaseous BEC, at JILA and MIT (Nobel 2001)
- 1995
Vicsekthe minimal model — collective motion as a true phase transition
- 1996
Grovershows a quantum computer can find a marked item in an unsorted list of N in about √N steps — a provably optimal quadratic speedup
- 1996
Parrondotwo games of chance, each losing on its own, alternate into a steady winner — devised as the game-theoretic shadow of the flashing ratchet (christened “Parrondo’s paradox” by Harmer & Abbott, 1999)
- 1998
Watts & Strogatzsmall-world networks — a few long-range links collapse the distance a contagion must travel
- 1998
Page & BrinPageRank — rank the web by its link structure alone; a random surfer’s equilibrium, and the founding of Google
- 1998
Gammaitoni, Hänggi, Jung & Marchesonipublish the landmark review of stochastic resonance, establishing it as a universal phenomenon in nonlinear noisy systems
- 1999
Jos Stam“Stable Fluids” — an unconditionally stable solver; real-time fluids in a browser
- 1999
Barabási & AlbertEmergence of scaling in random networks — growth plus preferential attachment breeds a scale-free degree distribution P(k) ~ k⁻³, the hubs of the web made inevitable
- 2000
Nakagaki, Yamada & Tótha brainless slime mould (Physarum polycephalum) finds the shortest path through a maze between two food sources — solving a problem with its body, not a nervous system (Ig Nobel, 2008)
- 2000
Drăgulescu & Yakovenkothe statistical mechanics of money — if agents conserve and randomly swap it, wealth relaxes to the exponential Boltzmann–Gibbs law, money as energy
- 2000
Chakraborti & Chakrabartilet each agent save a fixed fraction before trading and the exponential becomes a peaked Gamma distribution — a self-organised middle class
- 2000
Bouchaud & Mézarda wealth model where multiplicative luck plus exchange can condense almost all the money onto a vanishing fraction of agents — economic oligarchy as a phase
- 2000
Brussthe odds theorem — a single one-line rule for a whole class of stopping problems: sum the odds of the remaining trials and stop the moment that sum passes one; the 1/e law falls out as a special case
- 2001
Pastor-Satorras & Vespignanion scale-free networks the epidemic threshold can vanish — hubs change everything
- 2001
Jaegerintroduces the Echo State Network: leave a large random recurrent net fixed and train only a linear readout off its activity — turning recurrent learning into one cheap regression
- 2001
Hubbard, Schleicher & Sutherlandhow to find all roots of a polynomial by Newton’s method — a universal grid of starting points that cannot miss, Cayley’s question finally engineered
- 2002
Couzinmaps the switch between swarm, torus and aligned flock
- 2002
Maass, Natschläger & Markramarrives at the same idea from neuroscience — the Liquid State Machine: a spiking cortical microcircuit as a fixed “liquid” whose ripples a simple readout decodes
- 2002
WolframA New Kind of Science argues computational irreducibility is generic — that for most simple programs the only way to know the outcome is to run them
- 2002
Auer, Cesa-Bianchi & FischerUCB1 — act on the upper confidence bound of each arm, optimism in the face of uncertainty, and achieve logarithmic regret with a simple, finite-time, distribution-free rule
- 2003
Galperin“playing pool with π” — two blocks and a wall count their own collisions to 3, 31, 314, 3141…: a mass ratio of 100^(d−1) spells the first d digits of π
- 2004
Cookproves Rule 110 is Turing-complete — a universal computer
- 2005
Strogatzthe Millennium Bridge wobble: pedestrians lock step with the sway
- 2005
Nobel — Schellingthe Sveriges Riksbank Prize to Schelling (with Aumann) for game-theoretic analysis of conflict and cooperation — the segregation model among its legacy
- 2008
Ballerinireal murmurations: each bird tracks ~7 neighbours, by rank not distance
- 2008
Sugiyama et al.drives 22 cars around a single-lane ring told only to hold a steady speed — and a stop-and-go jam forms on its own and crawls backward, proving the model right on a real circular track
- 2009
White & Nylanderthe Mandelbulb — take the nth power of a point in spherical coordinates and z → zⁿ + c becomes a 3D fractal with genuine surface detail
- 2009
Lukoševičius & Jaegerunify the two strands under one name — reservoir computing — and set the practical recipe: tune the spectral radius, leak rate and input scaling, then fit the readout
- 2010
Jonesreproduces Physarum as a multi-agent model: thousands of particles that sense, steer toward, and deposit a chemoattractant trail — from which transport networks emerge with no central control
- 2010
Tero et al.fed oat flakes at the 36 cities around Tokyo, the slime grows a network rivalling the real rail map on cost, efficiency and fault-tolerance — and they distil it to an adaptive-conductivity rule
- 2012
Krizhevsky, Sutskever & HintonAlexNet: the same gradient descent, scaled to GPUs, wins ImageNet and ignites deep learning
- 2012
Sugihara et al.convergent cross mapping — “shadow manifolds” turn reconstruction into a test for causation between time series
- 2015
DeepMindthe Deep Q-Network learns to play 49 Atari games from raw pixels and the score alone, at human level — Q-learning with a deep net as the value function
- 2015
Sohl-Dickstein et al.deep unsupervised learning by nonequilibrium thermodynamics — destroy data with a slow diffusion, then train a network to reverse each step
- 2016
DeepMindAlphaGo defeats Lee Sedol at Go — self-play reinforcement learning plus tree search solves a game long thought a decade away
- 2016
Guminreleases Wave Function Collapse — a constraint-propagation tiler that learns adjacencies from one sample image — and procedural generation never looks back
- 2018
Pathak, Ott et al.a reservoir trained only on data forecasts a chaotic system for several Lyapunov times and even recovers its attractor — model-free prediction right up to the horizon chaos allows
- 2019
Event Horizon Telescopephotographs a black hole's shadow for the first time
- 2019
Song & Ermonscore-based generative modelling — learn the gradient of the log-density and sample by following it with Langevin dynamics
- 2019
Google Quantum AISycamore (53 qubits) samples a random circuit in 200 seconds that they estimate would take a classical supercomputer millennia — the first claimed quantum advantage
- 2019
ChanLenia — Conway’s Life let go of its grid: continuous in space, time and state, one differential update grows a whole zoo of smooth, self-propelled organisms
- 2019
Brownshows the bouncing blocks are Grover’s quantum search in disguise — the same 2θ rotation per step, the same ⌊π/θ⌋ count, one run in wood and one in amplitude
- 2019
Petersthe ergodicity problem in economics — for multiplicative wealth the time average is not the ensemble average, so a gamble can enrich the average while ruining almost everyone: a century of utility puzzles reread as one confusion of averages
- 2020
Ho, Jain & Abbeeldenoising diffusion probabilistic models — the clean recipe that made diffusion the engine behind modern image generators
- 2021
Song et al.unifies diffusion as a reverse-time SDE with a deterministic probability-flow ODE twin — one framework for every sampler
- 2022
Aspect, Clauser & Zeilingerthe Nobel for the experiments proving the world is not locally real
- 2023
Smith, Myers, Kaplan & Goodman-Straussfind the “hat”, a single tile — an einstein — that tiles the plane only aperiodically, ending a sixty-year search for one stone that never repeats
- 2024
Hopfield & Hintonthe Nobel Prize in Physics for the physics of memory and learning in neural networks
- 2024
bbchallengea distributed, machine-verified proof settles S(5) = 47,176,870 — every 5-state machine now known to halt or run forever, sixty years after the question was posed