A famous mathematician calls the department

FJ Craveiro de Carvalho

From TopCom, Volume 11, #1

I cannot say that my 35 year mathematical life has been particularly gratifying or exciting. I never proved any big theorems, the teaching has become more and more boring and assessment has always been a hard task. However, on the way, I have also met interesting people and a number of amusing (and amazing) incidents stick out from my memory.

X is a very famous USA based mathematician, the type of mathematician who could have won a Fields medal. He is in his 70s and has written many textbooks at both research and teaching level. Books that I used as a research student and later, when preparing some courses I had to teach.

A few years ago a student of mine had to write a short dissertation as part of her Maths degree. Basically she had to read and understand a chapter of a book by X and then rewrite it in her own words.

Soon after she started, she came to see me for there was a point at the beginning of a proof she could not understand. I tried very hard but got nowhere. Hence I decided to write and ask X if he would clarify that point for me.

One afternoon I was informed the telephone operator in my department had been very busy looking for me but with no success. X had called the department and wanted to talk to me very much. In the end a colleague of mine with my surname had taken the call. I was very intrigued but unfortunately my colleague was not available.

When I got home I was asked who X was. He had called and, again, wanted to talk to me. I was going to receive a letter which I must not open but destroy. He would call back at dinner time.

By now I was totally puzzled. Right, I had written to X but I could find no reason to have three calls from USA on the same day. Well, there might be one. X is known to be a very tough man. In his reply, I thought, he might have gone over the top, insulting me for being so stupid and not having understood something which was basic and obvious. Now he regretted it and did not want me to read the letter.

I did speak with X but cannot remember the details. He insisted on my not reading the letter. Another one was on its way which, in fact, stated an extra assumption that was needed to obtain the desired conclusion.

What would you do? I must say I did not resist and, expecting all sorts of insults, opened the letter. At the end of the day, X was polite but, in answering my question, he had made a pretty obvious mistake. Having realized that, he was likely not to want me to see it.

What was the reason for such a fuss? As I have said above, X is very tough and has been involved in a number of extremely public and ferocious disputes. Might he have feared I would expose him? Actually another famous mathematician wrote very critically about X's behaviour and draw his attention to the fact that after all not everything was mathematically correct in one of X's famous books.

I kept the letter but I do not know where and, frankly, I cannot be bothered to look for it. It may happen that one day someone going through my papers comes across it, does not think twice and throws it in the wastepaper basket straightaway.

Postscript: Unfortunately X died not long after this article was written. Our paths crossed for a very brief moment in the mid-90s, at the University of Reading, where I heard him lecture. I should have said thank you to him but, honestly, I did not dare to.