In Memoriam – Joe Polchinski

In attempting to write appropriate words about Joe, I struggled with trying to be succinct and hoping to be complete. Eventually I realized what should have been obvious. No few words could do Joe justice; no finite description of this incredible human being could be complete.

Elsewhere on this site for Joe, there is reference to a funny story from Stan Nicholson of Joe and his Tesla encountering the Sierra Nevada mountains, which Stan labels “the physicist forgets about gravity.” When I read it, I could instantly picture Joe, in his self-deprecating way, telling the tale. But it’s much more than – “the physicist forgets about gravity” is the perfect description of Joe himself.

Of course Joe could be serious. The sustained periods of intense concentration and the passion he brought to his work were emblematic of the seriousness required for his spectacular contributions to the physics. But all too often, affect and academia go hand in hand. Joe was a man utterly without affect. What you saw was what you got with Joe. It came through in his clear writing, his openness with colleagues and especially students, his infectious grin and yes, in his intolerance of fools.

Joe was my oldest – in the sense of longest duration – friend in physics. We met in out first few days at Caltech in September 1971. Joe recounted some of those memories in his wonderful autobiographical arXiv post. Here are a few more:

-The summer after our first year, we shared an apartment off-campus. We were both doing research doing the day, and working through Volume III of the Feynman lectures in our spare time, Joe at warp speed, me at decidedly non-relativistic velocities. It was amazing to see Joe encounter some new concept, think hard about it, then have complete grasp of the topic at his fingertips for some new problem.

– Joe had an earlier encounter with gravity when he had a front blow-out and crash while descending in the San Gabriel mountains. He said he waited until he stopped rolling, stood up, and rolled three more times.

– A more frightening incident on the bike occurred the summer after our sophomore year. Joe was riding solo in a sketchy area of Pasadena when he was attacked, apparently by someone throwing a brick in his face. His bike was stolen and his jaw was broken. So we spent that summer living in a professor’s house with several other classmates, I in full-length leg cast (another ill-fated biking affair), Joe with his jaw wired shut. Since Joe could not eat his beloved hamburgers with ketchup, he attempted to liquify one in a blender – it did end well.

– That summer, Joe’s mother stayed with us for a while to care for Joe. One morning she tartly but correctly explained some basic etiquette to me, which I had neglected by overthinking the obvious. I’m glad I had a chance to revisit this with Joe during my last visit with him.

-At some point towards the end of our undergraduate years, we were tutoring some incoming students. Many of them wanted to know “What’s the formula for this problem?” Joe mentioned to me that he’d like to teach F=ma one day, then change the symbols to m=Fa the next day, and so on. I am sure he tempered his views on pedagogy soon thereafter, but clearly he was already thinking about how to teach physics.

-In or about this same time, Joe mentioned to me that his measure of a good physicist was how many different ways they could solve the same problem. Another measure he mentioned was along the lines of “how do you know what you know.” What is striking to me is that Joe moved from knowing virtually no physics when entering Caltech to having a deep appreciation for how it all worked and was held together in just 3-4 years.

-Prior to an epic bike ride from Berkeley back to Pasadena during spring break of our senior year, Joe and I visited the UC-Berkeley Physics Department, where we were given a warm reception by then-chair Geoffrey Chew, complete with a tour of Lawrence Berkeley Lab and lunch in the lab cafeteria sited high above Berkeley. Despite my tendency to overthink things, it did not occur to me for many years that this impressive hospitality would have been much less likely had I been visiting without my soon to be famous classmate.

-Chew’s hospitality worked. Joe and I both went to UC-Berkeley for graduate school, where I spent as much time at the gym as Joe did quickly absorbing the entire graduate curriculum.Joe didn’t need to spend much time at the gym. Although he had only a modest interest in sports as a child, he was a natural athlete. Joe was the star hitter on our ragged team of scientists, engineers and mathematicians (“old but slow”) that won the Cal intramural championships in 1978.




-Many years later, in 2004, Joe spoke on gauge/gravity duality at the biggest conference in my field, Quark Matter. The application of string theory methods in nuclear physics was brand new at that time, and (for silly territorial reasons), very controversial. But Joe was like a rock star. We had lunch together, with many young students and postdocs, and once again it was clear who was the main attraction.

These memories are but a tiny sample of the multitude I have of Joe. I can’t recall our first bike ride together, but as Joe recounts in his “Memories…” there were many. I will never forget our last ride together, with Dorothy accompanying Joe on their tandem, in October 2016. It hurts so much to write “last”, but all the same this is a treasured memory.




Dorothy was kind enough to call me the night before Joe passed. This too is a (profoundly sad) memory I will cherish forever. Dorothy was a rock; I was not. As Joe so often noted, Dorothy was the best thing that ever happened to him, and my heartfelt sympathies go to Dorothy and Joe’s family. The outpouring of love and affection on this site and elsewhere will never replace Joe, but it demonstrates so impressively the enormous number of lives he touched. Joe was and is an inspiration and an aspiration – as a man, a husband, a father, a brother, a son, an athlete, a colleague, a scientist, and a friend.

Bill Zajc
February 5, 2018.