As many of you will have heard by now, Joe Polchinski sadly passed away on Feb 2, 2018, after a long battle with cancer. For FQXi, this marks not only the loss of a brilliant mind, but a dear friend.
There have been many tributes from Joe's colleagues celebrating his life and work. You can learn more through those links about his pioneering work on string theory, in particular, his role in the discovery of D-Branes (with Jin Dai and Rob Leigh), objects to which the ends of open strings can become tethered. (Matt Strassler has a wonderful discussion about the significance of this in relation to a description of black holes in string theory, and to the discovery of fundamental dualities between descriptions of physics using strings, black holes and gravity to those using quantum fields and particles.) But Joe's achievements go beyond that, including his work on the string landscape (with Raphael Bousso) and more recently, articulating the blackhole firewall paradox, as the "P" in the AMPS team (with Ahmed Almheiri, Donald Marolf and James Sully). He won numerous awards, including a share of the $3-million Breakthrough Prize in 2017.nI am sure that in the coming days, many FQXi members who worked closely with Joe Polchinski will add more tributes, here and elsewhere.
Speaking as a science writer, I am sure many journalists would join me in saying that Joe was exceptionally friendly and supportive when it came to explaining his own work, and that of his colleagues. And I wanted to add one anecdote based on my many interactions with him from that perspective. The last time that I met with Joe in person was while I was researching my book. We spoke about his work on D-Branes, and the series of related discoveries by others around that time that make up the "second superstring revolution." He was truly animated, scribbling on the blackboard and talking through how the realisation came aboutin the mid-90s. I asked him how exciting it was, back then. Was he aware of his work's significance? Proud of this immense accomplishment?
Joe stopped, chalk in hand, and thought for good while, reaching back to how he must have felt at the time. "I'll tell you something funny, just as a personal note," he said. One of his sons, he explained, played roller hockey, and Joe was asked to coach the kids' team. His first season of coaching coincided with the D-Brane discovery. "It was weird...I was much more emotionally involved in the coaching than I was in the D branes." And it was the roller hockey with his son, he noted, that was the real highlight of his year.
Our thoughts are with Joe's family and friends.
Joe Polchinski's: "Memories of a Theoretical Physicist"