Newly found letters show Georg Cantor stole his famous infinity proof

Ellsworth Toohey · Boing Boing ·

3 min read Original article ↗

Georg Cantor's 1874 proof that infinity comes in different sizes reshaped mathematics. It also appears to have been stolen. Newly discovered letters show that Cantor's colleague Richard Dedekind provided key proofs that Cantor published under his own name, reports Quanta Magazine.

Demian Goos, a 35-year-old German Argentine mathematician and journalist, tracked the letters down through Cantor's great-granddaughter, an archaeologist named Angelika Vahlen, who had donated family papers to the University of Halle. One letter, from November 30, 1873, had been hunted by historians for decades and was presumed destroyed during World War II. Dedekind used those pages to walk through his proof that algebraic numbers can be matched one-to-one with whole numbers — the same result Cantor would publish months later in Crelle's Journal as if it were his own.

Dedekind noticed. In a private note written after the paper was published, he noted that his work had appeared "almost word for word" under Cantor's name. But he never went public, and the mathematical community preferred its lone-genius story. Historian José Ferreirós accused Cantor of plagiarism in a 1993 paper, but without the missing letter, other biographers dismissed the charge.

Cantor had strategic reasons for concealment — he used a misleading title to sneak the infinity proof past Leopold Kronecker, who sat on the editorial board of Crelle's Journal and despised the very concept of infinity. But erasing Dedekind's contributions was a separate choice. "He was very young, very passionate and enthusiastic," Ferreirós said. "And he made a big mistake."

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