The man who knew infinity

Apostolos Doxiadis is someone who has been mentioned several times here. He is responsible (at least in part) for several remarkable works on or about mathematics: a novel (Uncle Petros and Goldbach’s Conjecture), a graphic novel (Logicomix, with Christos Papadimitriou), and a book of essays about mathematics and literature (Circles Disturbed, with Barry Mazur). On one occasion, we met up in London, and he offered to give a lecture to my first-year Mathematical Structures students at Queen Mary.

Out of the blue, he contacted me last week to invite me to a premiere of the new biopic about Ramanujan, based on the book of the same name by Robert Kanigel. It is a while since I read Kanigel’s book, but I have also read Hardy’s book on Ramanujan and Littlewood’s Miscellany, so I had a good idea what to expect.

The film, which goes on general release in Britain early next month, stars Dev Patel as Ramanujan and Jeremy Irons as Hardy. The bones of the story are: Ramanujan, a clerk in Madras with little education, sent letters to Hardy and other British mathematicians containing lists of his mathematical discoveries. The others dismissed him as a crank, but Hardy recognised his genius and brought him to Cambridge, describing it later as the one romantic incident of his life.

As well as the huge culture clash that Ramanujan had to contend with in Britain, the film brings out well the clashes between the two principals: Ramanujan trusted his intuition while Hardy was a stickler for proof; Ramanujan was a devout Hindu who attributed his intuition to the goddess Namagiri, while Hardy was an equally devout atheist. Yet somehow these two disparate characters hit it off and produced some extraordinary mathematics. Their interaction is well portrayed in the film, in a low-key way as befits the formality of Cambridge at the time of the first world war.

Indeed, I thought it was a very good film altogether. Compared to recent biopics of Turing and Hawking, it was remarkably accurate, and yet had a real story to tell, and told it well. Perhaps it was stretching a point a bit to have Hardy come close to admitting belief in God at the end, but it worked well in the drama.

What the film didn’t show was anyone actually doing mathematics. I guess the reason for this is clear enough. Also, I think there were a couple of anachronisms: I am not sure that anyone would have called Hardy “Harold”, though I don’t really know; and Major McMahon introduced his subject as “Combinatorics”, a word which was surely not used then (I think “combinatorial analysis” might have been more accurate), and described it with the words “glorified dice-throwing” which I am pretty sure were invented by Kanigel in his book to explain the subject.

I thought for some time that the film-makers had resisted the temptation to use the famous story about Hardy’s taxicab, but in the end they overdid things by putting it in twice: one of the very few flaws in the film.

Anyway, my advice is: see it, and take your non-mathematical loved ones to see it too. They may get some clue about what drives a mathematician.

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I was struck recently when I read this passage in E. R. Dodds’ The Greeks and the Irrational, describing the actions of the gods and their agents, the Erinyes and moira, in the Iliad:

… The recognition, the insight, the memory, the brilliant or perverse idea, have this in common, that they come suddenly, as we say, “into a man’s head”. Often he is conscious of no observation or reasoning which has led up to them. But in that case, how can he call them “his”? A moment ago they were not in his mind; now they are there. Something has put them there, and that something is other than himself. More than this he does not know. So he speaks of it noncommittally as “the gods” or “some god”, or more often (especially when its prompting has turned out to be bad) as a daemon.

Every mathematician knows the experience of sudden illumination, an idea which will certainly make the proof work, so that no verification of this is needed for utter conviction. Where does this come from? We may have theories, but we can’t know for certain. Ramanujan is completely justified in crediting his to the goddess Namagiri, just as Gauss is to “the grace of God”.

Apparently, Namagiri was like a personal goddess to Ramanujan. In another context the Portuguese poet Fernando Pessoa said, “As each fountain has its own deity, might not each man have a god all his own?”