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The River of Calculus

Why did a shared language of rate and accumulation ripen in the late seventeenth century?

Ancient area methods, Kerala-school series, and work by Cavalieri, Fermat, and Barrow preceded independent general frameworks by Newton and Leibniz. The Bernoullis and Euler expanded them; nineteenth-century analysts including Cauchy and Weierstrass sharpened the foundations.

250 BCE–190010 city-to-city segments

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What changed between the cities?

  1. 1

    250 BCE–263

    independent comparison

    SyracuseLuoyang

    Two Ancient Traditions Bound an Endless Process

    In his 263 commentary on the Nine Chapters, Liu Hui repeatedly doubled the sides of regular polygons inside a circle and narrowed its area. He argued about the remaining pieces instead of reporting only a decimal. The exact writing room is unknown, so Luoyang is an editorial anchor for the Cao Wei textual world, not evidence of a modern completed integral calculus there.

    Filling without End while Keeping Hold of the Answer — Archimedes' Parabola → Cut the Circle More Finely and the Error Comes into View — Liu Hui's Commentary
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  2. 2

    850–1020

    translation and reconstruction

    BaghdadCairo

    Arabic Measurement Reworked More Than It Translated

    Ibn al-Haytham used sums of powers and geometric argument in problems including the volume of a paraboloid of revolution, while rebuilding the relation among light, vision, experiment, and mathematics in optics. Cairo anchors his mature career. These are major precedents in the history of integration, not a general integration algorithm or a completed fundamental theorem.

    Translating a Figure and Proving It Again — The Banu Musa on Measurement → Measuring a Curved Solid through Sums of Powers — Ibn al-Haytham
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  3. 3

    1150–1400

    regional problem network

    UjjainSangamagrama

    Set Instantaneous Motion Beside Infinite Series in India

    Series for sine, cosine, and arctangent and refined computations of pi are attributed to Madhava in later Kerala texts. Correction terms improved approximations rather than merely adding more terms. Madhava's own mathematical writings do not survive, and no documented route establishes a direct transmission of these results to early modern Europe.

    Trying to Calculate a Planet at an Instant — Bhaskara II → Adding Corrections to an Infinite Series — Madhava
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  4. 4

    1400–1609

    independent comparison

    SangamagramaPrague

    Compare Two Problem Pressures without Claiming Transmission

    After relentlessly calculating with Tycho Brahe's observations of Mars, Kepler recognized that planetary speed varies and that the line from Sun to planet sweeps equal areas in equal times. Prague anchors the work with observations and calculations. The area law is not itself calculus, but it forced changing speed and accumulated area into the same problem.

    Adding Corrections to an Infinite Series — Madhava → A Planet Sweeps Equal Areas in Equal Times — Kepler's Orbit
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  5. 5

    1635–1637

    problem reformulation

    BolognaLeiden

    Indivisibles and Analytic Geometry Made Curves Calculable

    La Geometrie, an appendix to the Discourse published at Leiden, used symbolic algebra and coordinate relations to classify curves and make tangent problems calculable. The familiar Cartesian plane was not completed by one person on one page. Still, the encounter of algebra and geometry greatly widened the possibility of treating changing curves through general rules.

    Comparing Area by Lines and Volume by Planes — Cavalieri → Turning Curves into Equations and Equations into Curves — Descartes' Meeting
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  6. 6

    1636–1664

    correspondence and teaching

    ToulouseCambridge

    Tangents and Areas Reached the Threshold of Inversion

    In Cambridge geometry lectures, Isaac Barrow showed that the tangent to a curve representing accumulated area is related to the original curve. Newton attended and helped prepare the lectures for publication. The result comes remarkably close to the fundamental theorem, but it is not the identical modern statement with today's functions, continuity hypotheses, and notation.

    Comparing Two Almost-Equal Values to Find Extrema and Tangents — Fermat → At the Threshold where Tangents and Areas Undo One Another — Barrow's Lectures
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  7. 7

    1665–1686

    scholars and schools

    Woolsthorpe-by-ColsterworthParis

    Newton and Leibniz Build Two Calculating Languages

    Newton developed fluxions and series in private work around Woolsthorpe and Cambridge; Leibniz developed the language of d and ∫ in Paris notebooks and Leipzig publications. Independent discovery, private composition, publication, and the later priority dispute are kept separate.

    Newton’s fluxional manuscripts · Leibniz’s 1675 notes · publications in 1684 and 1686
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  8. 8

    1690–1740

    scholars and schools

    HannoverBasel

    The Bernoulli Brothers Spread Calculus

    Jakob and Johann Bernoulli in Basel spread Leibniz’s notation and methods across continental Europe.

    Lectures on differential calculus and early work in the calculus of variations
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  9. 9

    1730–1783

    scholars and schools

    BaselSaint Petersburg

    Euler Synthesizes Calculus

    Basel-born Euler reorganized calculus around functions while working in Berlin and Saint Petersburg.

    Introduction to Analysis, Differential Calculus, and Integral Calculus
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  10. 10

    1820–1880

    scholars and schools

    ParisBerlin

    Cauchy-Weierstrass Rigorization

    Cauchy in Paris and Weierstrass in Berlin rebuilt calculus rigorously with limits and epsilon-delta definitions.

    Cours d’Analyse and the epsilon-delta definition of limits
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How to read the lines

Each line is an editorial route through problems, texts, and practices. It does not imply one book moving in a straight line, a sole invention, or identical adoption everywhere.