Prison Mathematics (sentence extended)

We earlier spoke of the prison experiences of the stellar mathematicians André Weil and Neil Koblitz (“Adventures on Algebraic Geometry”).  It turns out that the author Arthur Koestler -- though not himself a mathematician --  likewise had fruitful recourse to math while imprisoned;  and, like Weil and Koblitz, was in prison for (roughly speaking) an unjust war (in this case, that of the Nazi-backed Franquistas against la  República in the Spanish Civil War).  As recounted in an excellent biography:

Koestler concluded that his hours spent by the prison window  scratching equations  had brought mystical insights into another realm of being.  He was filled “with a direct certainty that a higher order of reality existed, and that it alone invested existence with meaning.”  Koestler likened it to “a text written in invisible ink;  though one could not read it, the knowledge that it existed  was sufficient to alter the texture of one’s existence.”

-- Michael Scammel, Koestler (2009), p. 150

From this metaphor, Koestler drew the title of his psycho-political memoir, The Invisible Writing.

[Footnote:  One might include Galois -- another anti-tyrant -- in this company.  Though not imprisoned, he carried out his last great work  under effective sentence of death.]

[Post-footnote:  We are each of us, actually, under sentence of death.]

[Update 23 November 2013]  From the memoir of a front-rank mathematician, and refugee from Soviet oppression:

While in prison, Weil wrote a letter to his sister Simone Weil, a famous philosopher and humanist.   This letter is a remarkable document;  in it, he tries to explain  in fairly elementary terms (accessible even to a philosopher -- just kidding!) the “big picture” of mathematics  as he saw it.  Doing so, he set a great example to follow for all mathematicians.  I sometimes joke that perhaps we should jail some of the leading mathematicians  to force them to express their ideas in accessible terms, the way Weil did.

-- Edward Frenkel, Love & Math (2013), p. 96

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Other historical examples:

     Poncelet in prison, reviving projective geometry.

Not everyone is so tough:

Brouwer would spend many a university holiday in the army.  The most lasting effect of his military training  was that it ruined his health and his nerves.

-- Dennis Hesseling, Gnomes in the Fog:  The Reception of Brower’s Intuitionism in the 1920s (2003), p. 28

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