Goodbye Letter to Hassan by Irek Zawadzki

Dear Hassan,

As I read again your latest email sent on September 3, in which you describe with your usual humor and great excitement your latest discovery of new class of point vortex equilibria, I still cannot fathom the bitter fact that this is the last email I will ever receive from you. To cope with the pain I try to think of all the happy times since we first met on January morning in 1987.

I remember our first meeting very well. I was 25 years old, a refugee from then communist Poland, having completed in Warsaw more than enough coursework for an undergraduate degree but without a final diploma. The administrators at UC San Diego didn’t quite know what to do with me. Finally Professor Libby suggested taking two graduate courses through the university extension to prove my abilities. After completing the courses, Professor David Miller (then Chairman of the AMES department) suggested that I call you. I made the phone call right away. A pleasant and warm voice answered on the other side and agreed to meet with me. The next day, after a short conversation in your office lasting no longer than 5 minutes, you welcomed me as your new graduate student with a firm handshake, and you instructed me to go to the administrative office to fill out the paperwork for a graduate assistantship.

Just like that, being barely introduced, you agreed to take me under your wing. It was one of the most exciting days of my life. I shall forever be grateful to you for it. Thank you for seeing in me a potential and giving me a chance of a lifetime.

I vividly remember your great sense of humor. Like the day when you gently admonished me for giving you the nickname “Big Dog”. It was during one of those fun meetings in your office when you were trading witty jokes with Scott Jones and you remarked that “calling one’s advisor a dog is not the best career move”. Point well taken, but I am sure you knew that the nickname wasn’t in any way disrespectful. I still think it fit nicely someone like you, with somewhat imposing appearance and, more importantly, someone who I clearly saw as great leader and advisor. And let me share with you a little secret: I was not the only one who liked that moniker. In fact, for about 5 years after my graduation you were still affectionately referred to, in many e-mails within a certain group of your former students, by your “initials” BD.

I also remember when we were walking together across the student plaza at UCSD, after the IUTAM Symposium on Mixing and Stirring that you organized. I told you that I was planning to start the presentation of our paper by saying that “this research was conducted under the watchful eye of Professor Hassan Aref”. As you recall you were parading during the entire conference with your thick glasses and a big patch on one eye because of an infection. I told you that I decided not to say it because it might be construed as disrespectful. You laughed and said immediately: “You should have used it! It would have been so funny!” That was quintessential you, never missing a good opportunity for some entertainment even if it were at your own expense.

I guess what I have learned from those two experiences is that it’s OK to sometimes poke one’s advisor in the eye (figuratively speaking, of course), but one should never, ever call him a “Dog”.

I remember our meetings at your Scripps office, and especially the one when we were brainstorming various initial conditions for two vortex rings, as we tried to find one where they would link with each other as in a chain. I was somewhat disheartened by all my earlier failed attempts and was

about ready to give up but you would not let go. As usual you were correct about encouraging me to keep going. Right after that memorable meeting I had my Eureka moment to start with linked vortex rings as initial conditions and run the numerical simulation ‘backwards in time’. I remember the broad smile on your face when I brought to our next meeting the solution to our quest. The next morning you met me with a copy of a paper ready to be submitted to the journal Nature. I understood then that there was never doubt in your mind about the existence of the solution, and you were just patiently waiting for me to discover it on my own. Thank you for that great lesson of perseverance.

I remember the wonderful time we had at parties that you and Susanne hosted for your students and colleagues at your house in Solana Beach. I remember the fairly formal meals at a table set by Susanne as if it were intended for a royal visit. And the fun we had afterwards talking, laughing, trading jokes, playing games with Mike and Thomas, listening to you and Susanne playing piano duets, or watching you winning speed chess with Mory Gharib in a time, that would take me to make a single move. With Ryoko’s and my families thousands of miles away those parties really felt like home.

I remember your infinite patience and commitment in dealing with your students. I know it well as I was guilty of testing that patience to its limit. I still recall when you returned corrected copy of my first paper. It seemed to have more comments written by you in a bright red color than the black text that I composed. Being a relative beginner as an English speaker I was still making the rookie error of confusing “it’s” with “its”. Of course you managed to diligently catch all the redundant apostrophes throughout the paper, until the top of the last page where you finally ran out of patience and underlined the mistake with triple line and added big “SIC!” in capital letters just above it. Needless to say I finally learned my lesson. And I want to thank you for writing the glowing letter of recommendation (and for personally signing all 150 copies of it) when I was sending my job applications. Your letter helped me land a job during a recession and build a rewarding career.

I remember that during the years after my graduation, you always impressed me by how you always managed to find time to respond to my emails almost immediately. And it never was just a quick hello. You always wrote a paragraph or two about your latest endeavors and you gave me a thorough update on the whereabouts of my college buddies. Your messages helped me maintain and nurture many friendships from the years at UC San Diego.

There were many other memorable moments. Like when Kapil, Thomas, Stefan and I brought a homemade pie to your Scripps office to celebrate your 40th birthday. Last year, on the occasion of your 60th birthday you commented on the picture taken right after eating that pie, that it “should be classified” because you “looked like a nerd”. Well, maybe you did look then a bit “nerdy”. But I can unequivocally say (and I am sure everyone who has known you would agree) that you were the nicest nerd I met in my life.

It is time to say good bye now. I know life will go on, the memory of the shocking news that arrived on September 10 will fade and become less painful, and we all will sleep better. We will always carry with us a bit of sadness because we can never see you again, but also an immense joy from the awesome privilege to have known you personally. Rest in peace Hassan.

Irek Zawadzki, September 15, 2011