An autograph from Don Knuth

One of the good things about living in the San Francisco Bay area is that there is always an abundance of interesting events in which chances are you are going to meet, or at least listen to, interesting people. Last Thursday, Donald Knuth, one of the most well-known Computer Scientists in the world (for a good reason: he wrote the Art of Computer Programming, the bible of theoretical Computer Science) was giving a lecture that was open to the public at Stanford University in order to present his latest work on Volume 4 of the Art Of Computer Programming.

I went to Stanford’s campus, which was easily 5 times bigger than the University of Toronto campus, in rush to be there on time for the lecture. When I got in the auditorium, I saw a very tall and bright figure in the front; it was him. Don Knuth was certainly taller than I had expected (and older too). I grabbed the first free seat that I could find, one on the 5th row and started observing the way he moved and talked to people, as if he were an alien of some sort.

He talked to a lot of people in the front two rows, asking them where they came from and who they were. “Oh, you’re one of my grand students,” he said to a person after recognizing his name, probably from some paper. I kept wishing that he’d come to the 5th row, so I could tell him that I came from the University of Toronto. “Who are you and what are you doing here?” he’d probably say, just like in the XKCD comic.

The time for the lecture to begin had finally come, and he was going to present a data structure that he was analyzing in Volume 4: Binary Decision Diagrams, which can be used to represent (most of the times) a combinatorial explosion of possible choices (e.g. all Boolean functions on a fixed number of variables) in a compact way. He sat on his chair, and said that he was only going to start talking if he’d count to ten and nobody would enter the auditorium while he was counting. To make it more interesting he started counting in octal…the audience started giggling in binary.

It wasn’t long before he revealed his humorous side: “Some of you might be wondering why it took me so long to write this part of Volume 4. Well, I am getting older and Computer Science is getting harder…,” and we burst into laughs. It’s always awesome to hear great people joking about themselves.

The lecture itself was very interesting, more so because he was talking. At times it was hard to follow the methods and techniques he described to solve difficult problems using Binary Decision Diagrams (he had to be very brief because the lecture lasted only an hour while his book had 200 pages…), but most people weren’t there to be informed about the subject. They were there to see Don Knuth in flesh. So, after almost everyone left people started to approach him asking for photographs. I’d do the same but my camera’s batteries had died and the charger was back in Toronto, where I had forgotten it (on the plane I kept thinking that I had forgotten something).

So, I decided to ask for an autograph just like a couple of students were doing. They were holding a copy of The Art of Computer Programming which he signed. Now, as a Computer Scientist, I haven’t reached the level were I can use that book as a textbook or a reference so I haven’t bothered buying it, because I know that it would simply decorate my bookshelf and I don’t think that book deserves a fate like that. Anyway, I opened my bag and saw that I only had two books in there: “Learning GNU Emacs,” and “The Kite Runner.” I didn’t dare to go in front of him with a non-technical book, so I approached him and (I think) I said (in English):

– “Would you please sign this for me?.”

– “I don’t think I’ve ever signed an Emacs book before,” he said, looking amused.

– “Well, I have another book but it is fiction. I’d bring TAOCP if I had read it, but I haven’t. The only book of yours that I have read is ‘Things a Computer Scientist never talks about'”

– “Oh, don’t worry about it, I use Emacs from time to time. Many years ago, I was watching a show in a theatre. In the audience I recognized Agatha Christie. I had none of her books with me because I didn’t know she was going to be there, so I gave her an old handkerchief, which she signed. Where do you study?”

– “University of Toronto”

After I thanked him, a wide smile had occupied my face. I left the auditorium and started wandering around the Stanford campus, which seemed amazingly beautiful in that afternoon sun.