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9:24in productionCh. 1 · Proof, not postulate/ 9:24 · ceiling 15 min
Applied science · Physics

Liu Hui

Liu Hui didn’t borrow from Greece — he built a parallel mathematics, complete with proof, algorithms, and limits.

Liu Hui was a 3rd-century CE Chinese mathematician whose documented work includes proofs and algorithms in geometry, arithmetic, and surveying, notably in his commentaries on The Nine Chapters on the Mathematical Art and in Haidao Suanjing.

Chapters & takeaways4
  1. 1:04
    Proof, not postulate

    He proved the Pythagorean theorem — not just used it.

  2. 2:31
    The polygon that beat antiquity

    He approximated π to 3.14159 using a 3072-gon — more precisely than Archimedes or Ptolemy.

  3. 3:59
    Seven solids, one missing

    He computed volumes for seven solids — but left the sphere unsolved.

  4. 5:04
    Algorithms before algebra

    He solved systems of linear equations using Gaussian elimination — 1,500 years before Gauss.

Worth your time?

Yes. Study the whole thing.

4.5/ 5
What works
  • pythagorean-theorem-proof
  • pi-approximation
  • volumes-of-seven-solids
  • gaussian-elimination
What does not
  • volume-of-sphere
Study it if
  • historians-of-science
  • mathematicians
  • teachers-of-mathematics
Skip it if
  • general-audiences-unfamiliar-with-ancient-math
The written brief1 min read

What the work claims

Liu Hui claimed to prove foundational geometric theorems, compute volumes of major solids, improve π beyond Archimedes and Ptolemy, and systematise solutions to linear equations — all within commentaries on The Nine Chapters on the Mathematical Art and Haidao Suanjing.

How it was done

Liu Hui used geometric dissection, polygonal approximation, and a systematic algorithmic method — including what is now called Gaussian elimination — to derive results in geometry and arithmetic.

What holds up

His proof of a theorem identical to the Pythagorean theorem holds. His volume calculations for cone, cylinder, frustum, prism, pyramid, tetrahedron, and wedge hold. His π approximation of 3.14159 using a 3072-sided polygon holds.

What does not

He failed to compute the volume of a sphere. He explicitly acknowledged this gap and deferred it to future mathematicians.

Why it matters beyond the lab

It matters because it refutes the Eurocentric narrative that algorithmic rigour and geometric proof emerged only in Greece or Renaissance Europe. Liu Hui’s methods were operational, reproducible, and embedded in applied surveying — not abstract speculation.

Is it worth your time

Yes. His work demonstrates that rigorous proof, numerical approximation, and algorithmic problem-solving were fully developed in 3rd-century China — independently of Greek or later European traditions.

Same field · Applied science4 of 25
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