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Georg Cantor

1845 – 1918 · Germany

The man who proved that 'infinity comes in sizes'

Georg Cantor, working in Germany, founded set theory. Rather than treating infinity as one lump, he showed with his diagonal argument that the infinity of the real numbers is larger than the infinity of the whole numbers — that infinity itself has ranks. He faced fierce resistance in his day, yet his set theory is now the shared language of all modern mathematics.

Key contributions

  • Founded set theory
  • The diagonal argument distinguishing sizes of infinity
  • Proved the reals are a larger infinity than the whole numbers

Related concepts

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