from Zoubin Ghahramani

Sam was a very close friend and I miss him deeply and painfully. We worked closely for many years, we learned together, taught together and grew up academically together. He was a shining star and I wanted to claim to be a mentor but in truth I learned more from him than he did from me, and we were colleagues, almost brothers, curious to figure things out and share them with others. His joyful energy and creativity were truly infectious in a way that nobody can match. He was charming, open and approachable… you really wanted to be around him, bask in his glow, absorb his energy. It’s hard for me to accept that he’s gone. I don’t have the right words — I’ll never have the right words — to fill the gap that he leaves.

I met Sam when he visited Toronto while he was a grad student and I was just starting a postdoc. We instantly hit it off --- we would brainstorm for hours, Sam always inquisitive and positive, me listening and bouncing ideas off of him. We worked hard on our first of many papers, agonising over our reviews, and breathing a big sigh of relief when it was accepted. We were thrilled but terrified when we were asked to give a tutorial at NIPS... we spent literally months planning it out, preparing, and rehearsing it. During the tutorial we alternated presenting, and I remember sitting there while Sam presented, admiring his energy, enthusiasm, booming voice, and spontaneity, and hoping (in vain) that I could match it when it was my turn.

I remember when Sam decided to come to London to do his postdoc with us at the Gatsby Unit. What a coup it felt, that we have managed to get Sam despite his many offers! I felt lucky, as such a junior faculty member, that Sam, a peer, would be a postdoc with us. Those years, with Sam, Maneesh, Peter, Hagai, Emo, Yee Whye, Matt, Sham and so many others, and of course Geoff Hinton as our leader, were a magical time at the Gatsby Unit. We were a new and unknown outpost of the machine learning and computational neuroscience community, poised to make big waves. There was excitement in the air, and so much of that excitement emanated from Sam, always pushing boundaries, catalyzing ideas, and inspiring others.

We were often together at work or socially then. People sometimes confused us... I remember getting annoyed when our friends would accidentally call me Sam, and I'm sure he got annoyed at being called Zoubin.

I remember Sam at so many social occasions. A true charmer, at ease in any conversation, with strangers and close friends alike. I remember trying to get Sam drunk on his birthday.... which is hard since he didn't drink at all!

In the summer of 2008, Sam came to Cambridge while on sabbatical. I have wonderful memories of Sam, and Meredith, already showing a bump pregnant with their twin daughters, punting on the Cam on a beautiful sunny day.

Sam is sadly gone, nobody can replace him, but I can hold on to these memories.

His loss is truly tragic. He leaves behind Meredith, whose pain I cannot imagine, and two beautiful daughters. He leaves behind many colleagues and friends who truly loved and admired him.