Long before electronic machines, 'computer' was a job title for a person — often a woman — who performed mathematical calculations by hand or with a mechanical calculator: astronomical tables, artillery trajectories, NASA orbital paths. Electronic computers took over the calculations from the 1950s and 1960s onward, and by the time the job vanished it had already lent the machine its name.
Human computer no longer exists as a living trade. Here is what erased it, and which profession took on the work.
What else was happening then
1843
Ada Lovelace publishes the first algorithm
Translating an Italian paper on Charles Babbage's unbuilt Analytical Engine, Lovelace adds a note describing step by step how the machine would compute Bernoulli numbers — usually cited as the first published computer program.
1890
Hollerith's punch cards tabulate a census
Herman Hollerith's punched-card tabulating machines process the US Census in about a year, work that had taken the previous count almost eight years by hand; his company later becomes part of IBM.
1943–1945
Six women program the ENIAC
Kay McNulty, Jean Jennings, Betty Snyder, Marlyn Wescoff, Fran Bilas and Ruth Lichterman program the room-sized ENIAC at the University of Pennsylvania by physically setting switches and plugging cables, with no manual and no programming language to guide them.
1952
Grace Hopper completes the first compiler
Hopper's A-0 system at Remington Rand translates symbolic mathematical notation into machine code automatically, replacing the error-prone practice of hand-copying subroutine addresses — a direct ancestor of every compiler since.
Where that work lives now
Writes, tests and maintains the code that runs modern life — and is one of the first professions watching AI automate its own daily work.
💻 Software Engineer →Before electronic computers, aerospace research organizations like NACA and later NASA employed rooms of mathematicians — disproportionately women, including Katherine Johnson and Dorothy Vaughan at Langley — to perform trajectory and aerodynamic calculations by hand or with mechanical calculators. Electronic computers took over the raw calculation from the late 1950s onward, and the surviving human specialists were retitled 'aerospace technologists' or engineers rather than replaced outright.
1799–1903
Gliders and the birth of aerodynamic theory
Between Cayley's 1799 diagram and the Wright brothers' 1903 flight, aerodynamics developed almost entirely through unpowered gliders and wind-tunnel experiments. Otto Lilienthal made and documented more than 2,000 glider flights in Germany in the 1890s before dying in a 1896 crash, data the Wrights studied closely; they built their own wind tunnel in Dayton, Ohio, to test and correct Lilienthal's published lift tables before ever attempting powered flight. The era's central lesson — that theory has to be checked against instrumented, repeatable testing — became the field's defining habit.
What else was happening then
1903
The Wright brothers achieve powered flight
Orville and Wilbur Wright fly the Wright Flyer for 12 seconds at Kitty Hawk, North Carolina, on December 17 — the first sustained, controlled, powered flight of a heavier-than-air craft.
1904–1905
Prandtl explains the boundary layer
Ludwig Prandtl presents boundary-layer theory at a mathematics congress in Heidelberg, resolving a long-standing contradiction between theoretical and observed drag and giving engineers the tools to calculate lift and drag accurately.
1915
NACA is founded
The US Congress creates the National Advisory Committee for Aeronautics to coordinate government aeronautical research, the body that becomes NASA in 1958 and standardizes much of the field's early testing methodology.
1939
The first jet-powered flight
The Heinkel He 178, powered by Hans von Ohain's turbojet engine, flies near Rostock, Germany, on August 27 — a parallel British project led by Frank Whittle flies two years later.
Where that work lives now
Designs, analyzes and certifies the aircraft, rockets and spacecraft that leave the ground, working to safety margins that leave no room for guessing.
🛰️ Aerospace Engineer →Before electronic computing, engineering offices employed rooms of 'computers' — increasingly, from the early 20th century, women — grinding through stress tables, survey reductions and hydraulic calculations by hand and slide rule. Electronic computers and finite-element software erased the job title within a generation, though its holders' work sits silently inside every dam and bridge designed before 1960.
1750 – 1900
The heroic age of canals, railways and iron
Smeaton named the profession, France schooled it and Britain's industrial revolution made it famous: Telford's roads and aqueducts, the Stephensons' railways, Brunel's Great Western Railway and steamships, Bazalgette's London sewers, the Roeblings' Brooklyn Bridge. Engineers became public heroes — Telford was buried in Westminster Abbey in 1834 — while new institutions, journals and university courses turned a craft learned by apprenticeship into a taught, examined discipline.
What else was happening then
1818
The Institution of Civil Engineers is founded
Three young engineers meeting in a London coffee house found the Institution of Civil Engineers; Thomas Telford becomes its first president in 1820 and wins it a Royal Charter in 1828. Engineering acquires the machinery of a modern profession — membership standards, journals and examinations.
1824
Aspdin patents Portland cement
Joseph Aspdin, a Leeds bricklayer, patents 'Portland cement,' named for its resemblance to the prestigious Portland building stone. Combined with steel reinforcement later in the century, it becomes concrete as the world knows it — today the most-used manufactured material on Earth.
1883
The Brooklyn Bridge opens
The 486-metre main span, the world's longest and the first great steel-wire suspension bridge, opens after fourteen years of construction that killed its designer John Roebling and crippled his son Washington. Washington's wife, Emily Warren Roebling, had by then spent over a decade effectively running the project, and crossed first at the opening.
1940
The Tacoma Narrows Bridge tears itself apart
Four months after opening, the third-longest suspension span in the world twists itself to destruction in a 68 km/h wind, captured on film that engineering students still watch. 'Galloping Gertie' forces aerodynamics into bridge design and becomes the profession's standing lesson that a structure can satisfy every static calculation and still fail.
Where that work lives now
The profession that turns rivers, rock and gravity into bridges, roads and clean water — civilization's quiet load-bearing trade since Imhotep.
🌉 Civil Engineer →Before electronic computers, physics research groups — including the Manhattan Project at Los Alamos — employed rooms of people, disproportionately women, to perform the repetitive numerical calculations a theory needed checked by hand or with mechanical calculators. Electronic computers such as ENIAC (1945) and its successors took over that work through the 1950s, and the job title disappeared.
1687–1900
Classical physics matures
Newtonian mechanics extended into thermodynamics, statistical mechanics and, through Faraday's experiments and Maxwell's equations, a full theory of electromagnetism that predicted light itself was an electromagnetic wave. The word 'physicist' was coined only in 1840, by the English polymath William Whewell, as universities began creating dedicated chairs and journals for a discipline that had outgrown the older label of natural philosophy.
What else was happening then
1865
Maxwell unifies electricity, magnetism and light
James Clerk Maxwell publishes equations showing that electricity and magnetism are two faces of one field, and that light itself is an electromagnetic wave travelling at a predictable speed.
1900
Planck introduces the quantum
Max Planck shows that a hot object's radiation only matches observation if energy is emitted in discrete packets, or quanta — an assumption he treats as a mathematical trick that turns out to describe something real.
1905
Einstein's miracle year
Working as a patent clerk in Bern, Albert Einstein publishes four papers in a single year on special relativity, the photoelectric effect and Brownian motion, reshaping physics' basic concepts of space, time, mass and light.
1942
Fermi achieves the first controlled chain reaction
Enrico Fermi's team starts Chicago Pile-1, the first human-made self-sustaining nuclear chain reaction, built under a University of Chicago football stadium — the moment physics stops being a small-group discipline and becomes state-scale 'Big Science.'
Where that work lives now
Derives and tests the mathematical laws governing matter, energy, space and time, from a lone chalkboard to a 3,000-author particle-collider paper.
⚛️ Physicist →Long before electronic computers, teams of workers — disproportionately women, such as the 'Harvard Computers' who catalogued stars at the Harvard College Observatory from the 1880s, and NASA's Katherine Johnson, Dorothy Vaughan and Mary Jackson, who hand-calculated orbital trajectories into the 1960s — performed the mathematical labor now done by software. Electronic computers absorbed the role within a generation of becoming reliable and affordable.
1662–1899
Counting the living and the dead
In 1662, London haberdasher John Graunt published a statistical analysis of the city's parish death records, one of the earliest known attempts to draw general conclusions from collected data rather than individual anecdote. Belgian astronomer Adolphe Quetelet extended the idea in the 1830s with his 'social physics,' applying statistical distributions to human traits. Florence Nightingale carried the tradition into practical persuasion in 1858, using a polar-area diagram of Crimean War mortality data to convince the British War Office that poor sanitation, not combat, was killing most soldiers — becoming the first woman elected a Fellow of the Royal Statistical Society in the process.
What else was happening then
1908
Gosset publishes the t-test as 'Student'
William Sealy Gosset, a statistician for the Guinness brewery in Dublin, publishes 'The Probable Error of a Mean' under the pseudonym 'Student' because Guinness barred staff from publishing under their own names, introducing the t-distribution used in small-sample analysis ever since.
1925
Fisher publishes 'Statistical Methods for Research Workers'
Ronald Fisher, analyzing decades of crop-yield data at Rothamsted Experimental Station, publishes the book that establishes analysis of variance and modern experimental design as standard statistical practice.
1933
Neyman and Pearson formalize hypothesis testing
Jerzy Neyman and Egon Pearson's paper 'On the Problem of the Most Efficient Tests of Statistical Hypotheses' gives statistics its modern framework for deciding, with quantified error rates, whether a result is significant.
1962
Tukey argues data analysis is its own science
John Tukey's paper 'The Future of Data Analysis' argues that analyzing real data deserves recognition as a distinct science with its own methods, not a minor branch of mathematical statistics.
Where that work lives now
Finds patterns and builds predictive models from data — a 2008 job title built on three centuries of counting, testing and visualizing evidence.
📊 Data Scientist →Britain's Nautical Almanac, founded in 1767, was calculated by a distributed network of freelance human computers; Harvard College Observatory hired women from 1879 to measure and classify stars on glass plates at around 25 to 30 cents an hour; and NASA's computing pools, made famous by Katherine Johnson, carried the trade into the space age. Electronic computers erased the job title within a generation — though the word itself survives on every desk.
1600 – 1800
The telescope changes the question
Galileo's telescope made the sky a place with landscapes rather than a pattern of lights; Kepler's laws turned planetary tables into physics; Newton's Principia of 1687 explained both at once. National observatories at Paris (1667) and Greenwich (1675) put astronomers on the state payroll to fix longitude and time, and in 1781 a Hanoverian musician in England, William Herschel, doubled the solar system's known size by finding Uranus from his back garden.
What else was happening then
1838
Bessel measures a star's distance
At Königsberg, Friedrich Bessel measured the annual parallax of the star 61 Cygni: about a third of an arcsecond, placing it roughly ten light-years away. The measurement — which rivals Thomas Henderson and Wilhelm Struve nearly beat him to — ended a two-thousand-year argument over whether the distances to stars could ever be known.
1912
Leavitt's law creates the cosmic ruler
From photographic plates of the Small Magellanic Cloud, Harvard computer Henrietta Swan Leavitt showed that a Cepheid variable star's pulsation period reveals its true brightness, turning Cepheids into distance markers. Every cosmic distance measured since, including Hubble's, stands on a relation published in a three-page circular issued under the observatory director's name.
1929
The universe is expanding
Using Mount Wilson's 100-inch telescope, redshifts largely measured by Vesto Slipher and Milton Humason, and Leavitt's law for distances, Edwin Hubble showed that galaxies recede at speeds proportional to their distance. Georges Lemaître had derived the same law theoretically in 1927 in a French-language Belgian journal; in 2018 the IAU voted to rename it the Hubble–Lemaître law.
1967
Bell Burnell finds the pulsars
On 28 November 1967, Cambridge PhD student Jocelyn Bell Burnell confirmed that a quarter-inch of recurring "scruff" on her radio survey's chart paper was a source pulsing every 1.337 seconds — the first pulsar, a spinning neutron star. The 1974 Nobel Prize for the discovery went to her supervisor Antony Hewish, an omission still argued about.
Where that work lives now
The scientist who measures the universe, from Babylonian clay tablets to space telescopes, still deciding which flicker in the data is a discovery.
🔭 Astronomer →For two centuries, "computer" was a job title: teams of people calculating by hand, from the British Nautical Almanac's network of home-working calculators (begun 1767) to the Harvard Observatory's women computers and NASA's West Area Computing unit, where Katherine Johnson checked orbital trajectories John Glenn refused to fly without. Electronic computers erased the trade within roughly a decade of ENIAC's 1945 debut — the machines took the workers' very name.
1500 – 1800
Courts, academies and the calculus
Renaissance and Enlightenment mathematicians lived on patronage: Cardano and Tartaglia fought public equation duels for reputation and pupils, while Euler spent his career salaried by the imperial academies of St Petersburg and Berlin, and Lagrange succeeded him at Frederick the Great's invitation. Newton and Leibniz built the calculus that made mathematics the engine of the new physics — and their priority war showed that credit, then as now, was the profession's real currency.
What else was happening then
1900
Hilbert sets the century's agenda
At the International Congress of Mathematicians in Paris on 8 August 1900, David Hilbert presented ten of a list of twenty-three unsolved problems, declaring that in mathematics "there is no ignorabimus" — no unknowable. The list steered research for a hundred years; several problems, including the Riemann hypothesis, remain open today.
1931
Gödel proves incompleteness
A 25-year-old Kurt Gödel in Vienna proved that any consistent formal system rich enough for arithmetic contains true statements it cannot prove. The result demolished Hilbert's program of securing all mathematics on a complete axiomatic foundation, and permanently changed what mathematicians can honestly claim about their own subject.
1976
The four color theorem falls to a computer
Kenneth Appel and Wolfgang Haken of the University of Illinois proved that four colors suffice for any planar map, using about 1,200 hours of computer time to check nearly two thousand configurations no human could verify by hand. The department franked its mail "FOUR COLORS SUFFICE" while philosophers argued over whether an uncheckable proof counts — the first great crisis of computer-assisted mathematics.
1995
Wiles proves Fermat's Last Theorem
After seven years working in secrecy in his Princeton attic study, Andrew Wiles announced a proof of Fermat's Last Theorem at Cambridge in June 1993 — then spent fourteen months repairing a gap a referee found, closing it with Richard Taylor in September 1994. The proof, published in the Annals of Mathematics in 1995, ended a 358-year-old challenge scribbled in a margin.
Where that work lives now
From Babylonian scribes to Fields medalists and AI-assisted proof: the profession that turns hard questions into permanent certainty, one theorem at a time.
🧮 Mathematician →Long before electronic computers, teams of workers — disproportionately women, such as the 'Harvard Computers' who catalogued stars at the Harvard College Observatory from the 1880s, and NASA's Katherine Johnson, Dorothy Vaughan and Mary Jackson, who hand-calculated orbital trajectories into the 1960s — performed the mathematical labor now done by software. Electronic computers absorbed the role within a generation of becoming reliable and affordable.
1662–1899
Counting the living and the dead
In 1662, London haberdasher John Graunt published a statistical analysis of the city's parish death records, one of the earliest known attempts to draw general conclusions from collected data rather than individual anecdote. Belgian astronomer Adolphe Quetelet extended the idea in the 1830s with his 'social physics,' applying statistical distributions to human traits. Florence Nightingale carried the tradition into practical persuasion in 1858, using a polar-area diagram of Crimean War mortality data to convince the British War Office that poor sanitation, not combat, was killing most soldiers — becoming the first woman elected a Fellow of the Royal Statistical Society in the process.
What else was happening then
1908
Gosset publishes the t-test as 'Student'
William Sealy Gosset, a statistician for the Guinness brewery in Dublin, publishes 'The Probable Error of a Mean' under the pseudonym 'Student' because Guinness barred staff from publishing under their own names, introducing the t-distribution used in small-sample analysis ever since.
1925
Fisher publishes 'Statistical Methods for Research Workers'
Ronald Fisher, analyzing decades of crop-yield data at Rothamsted Experimental Station, publishes the book that establishes analysis of variance and modern experimental design as standard statistical practice.
1933
Neyman and Pearson formalize hypothesis testing
Jerzy Neyman and Egon Pearson's paper 'On the Problem of the Most Efficient Tests of Statistical Hypotheses' gives statistics its modern framework for deciding, with quantified error rates, whether a result is significant.
1962
Tukey argues data analysis is its own science
John Tukey's paper 'The Future of Data Analysis' argues that analyzing real data deserves recognition as a distinct science with its own methods, not a minor branch of mathematical statistics.
Where that work lives now
Uses clinical, trial and health-system data to generate reliable evidence for safer care, research and operational decisions.
🧫 Clinical Data Scientist →Before electronic machines, statistical and economic calculation was done by rooms of clerks — very often women — grinding through index numbers, life tables and national accounts by hand and by mechanical calculator. Early econometrics ran on their labor: Wassily Leontief's input-output tables of the US economy required years of organized hand computation. Electronic computers erased the occupation within roughly a decade of arriving.
1776 – 1890
Classical political economy
Smith's Wealth of Nations gave the subject a founding text, and for a century British political economy dominated: Ricardo on trade and rent, Malthus on population, John Stuart Mill's synthesizing Principles of 1848, and Marx's dissenting critique from the British Museum's Reading Room. It was public, polemical and untechnical enough for parliamentarians to argue over — and controversial enough that Thomas Carlyle branded it "the dismal science" in 1849, in an essay attacking political economists for opposing slavery on the grounds that markets should govern labor.
What else was happening then
1871
The marginal revolution
Working independently, William Stanley Jevons in Manchester and Carl Menger in Vienna both publish books grounding value in marginal utility — the worth of the next unit — with Léon Walras in Lausanne completing the trio in 1874. Thinking at the margin becomes the discipline's signature habit and its bridge to calculus.
1890
Marshall professionalizes the field
Alfred Marshall's Principles of Economics, the dominant textbook for four decades, popularizes supply-and-demand diagrams and the very name "economics" in place of political economy. With the American Economic Association founded in 1885 and new journals and chairs multiplying, economics becomes a career rather than a gentleman's sideline.
1936
Keynes invents macroeconomics
Amid mass unemployment, John Maynard Keynes publishes The General Theory of Employment, Interest and Money, arguing that economies can settle into prolonged slumps that only government spending can escape. The book creates macroeconomics as a field and, within a decade, a permanent demand for economists inside governments.
1944
Bretton Woods
Delegations from 44 nations meet at the Mount Washington Hotel in Bretton Woods, New Hampshire, in July 1944 to design the postwar monetary order. The lead negotiators — Keynes for Britain, Harry Dexter White for the United States — are economists, and the institutions they create, the IMF and World Bank, become two of the profession's largest employers.
Where that work lives now
The scholar of scarcity — from Adam Smith's pin factory to the central-bank decision room, still asked to predict what no model fully captures.
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