It was the Thanksgiving dinner gathering at their church when I first had an extended conversation with his family. Looking back, this is one of the bifurcation points of my life trajectory, another story. I still remember vividly that during the dinner, he inquired about the new developments occurring in mathematics; he talked about how quantum Hall effect was rooted in mathematics, his discovery, and then back to mathematics, and to physics. It was a warm moment, knowing that he walked through the same university gate on the same day as I did, in October 1978 at Fudan University.

We had met, chatted long and short, between meeting, off the tennis court, on dinner table, in the party, and once in his office, and once at the centennial night at the lawn of Fudan university.

Writing on, several encounters forced to my mind. One is his lecture on super high way in silicon material, on how to utilize his discovery on quantum Hall effect to realize super-conductivity, to revolutionize the semi-conductor industry. On his podium, he was confident, forward looking, and full of imaginations.

The second is during one conversation, between us two, when he said, every great discovery of mankind are rooted with simplicity. Kepler made the observations; Newton discovered the law of gravitation, making sense of the trajectories of stars. He went on, a beautiful theory will always be rooted on beautiful mathematics. It immediately came to my mind, that while I was working on Chern-Simons theory, his quantum hall effect was also based on his calculation via Chern-Simons theory, nevertheless.
The other moment, which I treasure, was at a dinner table when he talked about how a mont blanc pen would help bring creativity from his deep inner self. I couldn’t agree more.

He was such a human being, standing out on every occasion, for the simple reason that he was a person who was always in persuit of new boundary, in persuit of elegance, and in persuit of perfection.