from Max Welling

Dear Sam,

I find myself rechecking whether it is not all a dream after all. Your passing comes as an incredible shock. I will miss you: your person, your talks and your papers.

On 9/23/09 we had a brief email exchange where I asked about your current situation. Among other things you wrote back:

"Hopefully in a few years things will be more stable and we can try to put our lives back together. But I hope all is well with you and please let me know if you are planning a trip to NYC."

Of course I now wish I made that trip. I wish, like everyone who knows you, I could have helped you. I wish the laws of physics were time reversible.

You will leave very big footprints. I first met you at Caltech, then we shared a year of postdoc-ing at the Gatsby unit and finally two more years in Toronto where you had become assistant professor while I was still postoc-ing. I will confess, I envied you. Five years younger and so much more successful. Everyone knew you. You were (and still are) a role model of how to do research and communicate it to others. I remember this huge crowd of people around your poster on "Constrained Hidden Markov Models" at NIPS listening to your intoxicating explanations in your booming voice. I wished I could draw crowds like that.

During the Gatsby years you created a magical atmosphere that made me feel I was part of something really profound. I remember Geoff Hinton introducing your talk on LLE with: "if you don't like this there is nothing that you will like". I always walked away from your talks slightly hyperventilating, high on oxygen, re-energized to do my own research.

Your paper "EM Algorithms for PCA and Sensible PCA" had a very big impact on my career because it filled me with enthusiasm for the field. It was one of those nipsy papers with a really cute idea that unified two concepts (EM and PCA). I always wanted to ask you "why did you name it sensible PCA"? How I wish you were still around to give an answer.

Goodbye Sam. It was a great privilege and joy to know you. We will have to struggle to keep your spirit alive in our community. I will continue to be inspired to give talks "Sam's way": light, magical, humorous, energetic, interesting, inspired. I will continue to read your papers and give them to my students so they too can get touched by that spark.

I hope your children will read these stories when they grow up and know what a fantastic father they had. For Meredith, whose distress I can not fathom, I wish all the strength in the world to get through this horrible situation.

-Max