Wednesday, October 15, 2014

Fermat's last theorem - III

You thought you had escaped a bad dream with the last post, didn't you? But the title of this  post would have revealed to you that, like George Bush, you were a bit hasty in arriving at the conclusion that the mission had been accomplished.

Where we last left him, Andrew Wiles had become a celebrity but the peer review process was only beginning. This is a process that all scientific works have to go through before being accepted as correct. Wiles had to submit a complete manuscript to a leading journal.whose editor will then choose a team of experts who will then examine the proof line by line. The proof was so complicated that 6 referees were appointed with each given responsibility for one section of the proof. The process took a few months.

At first all the problems were minor and Wiles sorted them out quickly but there was one 'little problem'. And you are right - it had  to do with the Kolyvagin-Flach method which he had used in the proof. No matter how hard he tried he couldn't fix the problem. If he fixed the problem in one place,another problem cropped up somewhere else. The issue dragged on for months. (But tell me how did you guess it was the Kolyvagin-Flach method?)

Rumours started flying in the mathematical community - perhaps this was another in the long line of failed proofs for Fermat's Last Theorem. Wiles wanted to work in isolation and concentrate completely on the problem but this was not possible since he had become a celebrity. There was pressure on him to publish the incomplete proof so that someone else could try to correct the flaw but this would have meant the end of a childhood dream.

In desperation he took on a collaborator and struggled on for a while but the problem seemed intractable. He was on the verge of giving up when  one day in Sept. 1994, over an year after his initial presentation, he had an inspiration - all he had to do  to make the Kolyvagin-Flach method work was to use it in conjunction with the Iwasawa theory! Aren't you amazed by the man's brilliance? Simon Singh gives the views of a mathematician on the final 130 page proof in Fermat's  Last Theorem :
'I think that if you were lost on  a desert island and you had only this manuscript then you would have a lot of food for thought. You would see all the current ideas of number theory. You turn to a page and there is a brief appearance of some fundamental theorem by Deligne and then you turn to another page and in some incidental way there is a theorem by Helleguarch - all of these things are just called into play and used for a moment before going on to the next idea.'
Oh....Ah.. That Sounds Very Interesting. (As Douglas Adams said in Dirk Gently's Holistic Detective Agency , "Capital letters were always the best way of dealing with things you didn't have a good answer to.") But... er, can I exchange it for a Wodehouse? Much obliged.

But the question is, was Wiles' solution the same as Fermat's? It couldn't have been because Wiles' proof involved 20th century mathematics which had been unavailable to Fermat so Fermat's proof, if it existed, must have been simpler.

Believe it or not, I am through with Fermat's Last Theorem. Now you can safely breathe a sigh of relief, grab a restorative  drink and check Facebook.

PS: As a reward for your patience, here is a bit of nonsense math.

1 comment:

  1. I didn't understand Fermats theorems. My math fundamental got clarified thru the video. ..