Encounter with a bright angel

(How I learnt i.i.d. in information theory)

It happened a few years ago. It was a social gathering in a dining hall where ladies and gentlemen, boys and girls with different backgrounds were chatting all kinds of subject, ranging from weather and flowers to sea and sky, etc. I then noted by intentional glances that a lady whom I had been calling her angel in my heart several times was continuously staring at me for quite a while. While slowly approaching the table at the middle of our current locations to refill my cup I noted that she was also walking toward the same table. We arrived at the table about the same time. When I was making refill with the soft drink she gently put an ice cube into my cup. Immediately afterwards, we struck up a conversation and, naturally, the discussion topics were always starting from weather, flowers, philosophy, music, etc. Both of us felt being attracted to other's intelligence and broadness in knowledge. I was especially impressed by her logic and preciseness in her descriptions. "Oh, my god, what a bright angel!" I yelled in my heart, repeatedly.

As the discussions got to more personal and professional, it turned out that she was a math professor in the computer science department of a prestigious university. She was trained as a mathematician and specialized in graph theory, which explained why she was logical and precise in her talk. The internet booming drove her research interest to the field of computer and communication sciences and she was just taking a big research project on fiber communications. She had already heard from others that I was a very good physicist. She asked whether I could visit her university and gave an introductory lecture or two to her research group (about 15 people) on the physics of fiber optics. "Oh, my god," I thought, "women! No matter how good it appears their logic, they are still women!" She was thinking that since I was very good at physics I should know everything in physics! Well, I looked at this angel's 水灵灵的 anxious eyes with the attractive image of her putting the ice cube into my cup still dangling in my mind, I had no other choice but to say: "Let me check my schedule after I get back and I will send you an email on the possible time slots I can visit your university."

Of course, after getting back to my office, what I immediately checked was not my schedule but was to find out what this "fiber optics" was about. Luckily, it turned out that the "physics of fiber optics" was very closely related to "laser physics", which in turn happened to be loosely related to "plasma physics" that was the field I was working on at the time. I felt that I was able to prepare a three-hour lecture, describing the physics of fiber optics in layman's language to those people who are majoring in computer and communication sciences. In order to match my schedule with hers, it turned out that I had more than two months to prepare for the upcoming lecture. While preparing the lecture notes, I also visited her university webpage to find out more details on her academic background. I found and bought the main textbooks of several courses she was teaching. The textbook for the communication theory was the one by Thomas M. Cover and Joy A. Thomas: Elements of Information Theory. I read part of that book and learnt i.i.d. at that time.

The visit was pleasant and the lecture was a great success. We are still good friends.

(2005.06.27)