GRAPH THEORY · 1736 TO PRESENT
Some of the most important mathematics of the last three centuries began as a parlour puzzle about seven bridges in a Prussian city.
Four standalone stories trace how graph theory went from a question no one could answer to the invisible architecture of the modern internet.
Read in order, or dive straight into whichever story pulls you in.
Königsberg, 1736. Leonhard Euler proves the city's bridge puzzle is impossible, and accidentally invents a new branch of mathematics. What matters isn't the geography. Only how the pieces connect.
What Euler started. Graph theory as a field takes shape over the next two centuries. Quiet, academic, mostly unnoticed. Dénes König writes the first textbook in 1936, eight years before Normandy.
Normandy, 1944. The Allies face network problems graph theory could have solved. But the formal tools do not exist yet. They improvise. They win anyway.
RAND, 1955. American analysts study the Soviet rail network. The tools Normandy needed finally get built, motivated by the next potential war.
Today. Every packet you send traverses a graph. Every route you drive. Every recommendation you get. And, increasingly, every fact an LLM retrieves.
Story 01 · Königsberg, 1736
A puzzle no one could solve, until Euler stopped looking at the map.
Seven bridges, four land masses, one of Europe's most prolific mathematicians, and the insight that the answer depends on something other than what anyone was looking at.
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02Story 02 · Amsterdam, 1956
Edsger Dijkstra, a café on the Leidseplein, and twenty minutes without a pencil.
A demo problem for a new Dutch computer turned into the algorithm that routes every packet on the modern internet. The world had to wait twelve years for it.
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03Story 03 · RAND, 1955
Ted Harris, Frank Ross, and a classified map of the Soviet rail network.
A targeting study at RAND asked which rails to bomb to sever Soviet supply lines. The mathematical answer, max-flow / min-cut, was being written one floor away.
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04Story 04 · Stanford, 1998 and now
A bored surfer, a random walk, and the same algorithm running thirty years apart.
Random walks on the web graph built Google. Random walks on knowledge graphs are the frontier for making language models less confabulatory. One algorithm, two centuries of the web.
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