Letter from Zhen Cao

Dear Rudy,

Happy Birthday!

It is a greatly memorable moment. In Chinese, “Over 70 is already long live”. According to Confucius above 70, people are leading their life totally following their hearts and being motivated by nothing. What an altitude! At 80, you have been totally yourself and beyond any desires. However, as a Chinese, I might guess that you still have a little desire to have a wonderful party with your old friends, although you have already had a very happy and lovely family. I think this is exactly what this party is for. At this moment, I’d like to thank Xin-nian for organizing such a good symposium and express my great regret about my absence to the ceremony. I’d like to send this letter to you and wish Xin-nian to read it for me.

Nobody, even Rudy yourself, does not know how much I have learnt from you. It is actually not difficult to image how importantly the experience in Eugene, Oregon does to my career, at the very beginning of it, right after I got my PhD in IHEP. Collaborating with Rudy, I had the most fruitful period in my scientific life, not only in terms of the production rate, but also in terms of the wide coverage over various topics, including hadronic interaction, chaos, phase transition, critical phenomena, stochastic theory/modeling and so forth. Besides, it was a very important period for building up my style of research, presentation and teaching. I like to share a story with you here. On an international workshop in CCAST, Beijing around 2005 or 2006, I had my presentation about a cosmic ray experiment. Right after the session, Prof. Meng Dazhong reached me and asked “Did you work with Rudy before?” Please note that we had never met each other before. When he pointed that he just saw somebody (me) delivered a talk in entirely Rudy’s style, I was totally surprised! I had already left Rudy for Salt Lake City for 6 or 7 years and devoted myself to a totally different field, namely cosmic ray experiment. During that few years, I had developed quite a bit from a post doc to an independent experimentalist who had been leading an international collaboration of about 100 scientists from China and Italy. I thought everything was in my own style! This story may give you some flavor about how strong your personality is and how deeply people around you are influenced.

Once again, I wish I have been here in Seattle and presenting you and your dear friends something about what I am pursuing. Just because what I am pursuing, I have to stay here in Beijing and give a similar talk to totally different audience who are my reviewers in two days. The reviewing is so important that I cannot afford to miss. We are proposing to build the largest gamma ray survey telescope on the ground at above 4400 meters above sea level. The ultimate goal is to locate the sources of cosmic rays which were discovered by Victor Hess exactly 100 years ago. As something I can do for my absence in the ceremony that I really want to attend, I’ll visit you at Eugene when I arrive to the states once again. I have never visited the states for 3 years. I must do it soon.

Yours sincerely,

Zhen