from Chris Williams

I am writing this shortly after the commemoration event for Sam held at the Gatsby on Jan 25th. It was very good to get together to remember him, and to hear stories of his personal as well as intellectual qualities.

I remember Sam for his boundless energy, infectious enthusiasm, and generosity. One of my favourite memories of him is of several discussion sessions at the whiteboards in the tearoom at the Gatsby during his stay there 1999-2001, in particular with Geoff Hinton, Peter Dayan and Zoubin Ghahramani. These were a lot of fun, exploring ideas with energy, curiosity and a pleasure in finding things out.

It was always a treat to meet Sam at a conference or on a research visit. He would always have new things to tell, whether about his own work, or neat things that others had done. For example I remember him standing in my old office in Forrest Hill, Edinburgh, telling me about a backward pass algorithm for sampling from the posterior distribution in HMMs, and how it was a nice NIPS-y generalization of the Viterbi algorithm.

I last saw Sam in early December 2009 at a meeting in Vancouver. It makes me very sad to think I won't see him again, but perhaps one way for us to remember him is to try to aspire in some part to his standards of enthusiasm, creativity and curiosity.

from Yoshua Bengio

I've known Sam since he visited Bell Labs in the late 90's while doing his PhD. From these early interactions I had already been impressed by his intelligence, his warmth, and his outstanding ability to generously communicate and clarify ideas for others. Unsurprisingly, he quickly became a rising star in our field. He was one of the persons that made my trip to a meeting or conference worthwhile, since exchanging with him was always stimulating and heartwarming. He made me feel like his friend and valued what I expressed, in the way that counts the most for me, i.e., by truly trying to understand my ideas and bringing his own creative mind to the table. In turn, he sparkled my imagination with his own insights, making concepts that were previously fuzzy for me suddenly simple and obvious. In five minutes he managed to summarize the core idea in someone else's talk or paper, probably much better than the authors. Clearly, he was a teacher for me.

Very early in the morning after his death, I awoke with a message from Yann LeCun about the news. I was completely shocked. I felt disbelief and a loss akin to one I had felt a few years earlier when my closest cousin had died in a meaningless accident. Writing these words my throat is bursting with emotion. I am clinging to the image of his communicative smile.

So long, Sam, and thank you for everything you brought to this world. I will forever remember the beautiful human being you were, and for me and the many others you have interacted with, you will remain an intellectual giant of our community and hold a special place in our heart.

from Rich Zemel

I went to the memorial for Sam on Friday (Jan. 22nd) here at the University of Toronto. It was a very emotional and intense event, attended by ~200 people, mostly his friends and colleagues from the university, and his high school here in Toronto. In addition to Sam's father, and two long-time friends from his high-school days, some of Sam's closest friends in the computer science department spoke: Geoff Hinton, Craig Boutilier, and Renee Miller, and myself. I read out some statements and anecdotes from many of Sam's students and postdocs, who were unable to make the trip. Also, I was very happy to have gotten a chance to share a few of my own memories and thoughts about Sam.

Since I heard the awful news, I'm sure like many others I've repeatedly gone through my email, my Sam folder, dating back to when he first arrived, in 2001, a year after I had come to Toronto. His Science paper was just published, and he bowled everyone over during his visit, both in content and style.

Yet he sought my advice quite a bit at first, about funding, students, teaching, grants. Very soon it became clear to me that he needed no help from me, because he excelled in everything right away, as a:

• Faculty member: He threw himself into every issue and discussion, and we could always count on him for the pithiest, and often funniest comment at the meeting.
  
• Department citizen: He was some needed glue in the department, drawing it together. He regularly poked his head into faculty offices and attended meetings in other research groups.
  
• Great friend, and personal booster. I still remember a distinguished visiting speaker showing up for his allotted time-slot with me, which I was nervous about, yet he came in very excited about my newest project. I couldn't figure out how he knew, let alone why he was excited, until I realized that he had just talked to Sam, who had used some of his time telling the guy about it!
  
• Genuinely nice guy: It is the little things really show someone's character. With Sam one thing I recall is that early on I let him use my office and computer. I had a coral reef background, with tropical fish swimming. When I returned, there was a battery-powered water-filled coral reef toy, complete with swimming fish, next to my monitor. It is still there today.
  

After that I watched his star steadily rise. Yet his head did not swell: he still took an interest in everything, and was helpful to everyone. And he was a ton of fun at parties -- he somehow managed to be the goofiest and funniest guy at late-night parties at the conferences, without having touched a drop of alcohol.

He was also a ton of fun to talk research with, and to collaborate with on projects: a fountain of good ideas, generous with his time, and very respectful of student's contributions. I can remember several times, where we'd be stuck, in the depths of some derivation or failing simulation. And Sam would jump up, bounce over to the whiteboard, and write down a simple insight or equation that cut through the mess, putting us on track.

Finally, there are a few lessons I've learned from him I'm determined to try to emulate: his clear thinking, his lucid and simple explanations, but also his personal style, his genuine pleasure in others' successes. And he has also made me value my work friendships all the more -- realizing how important they are, and also what a great set of people there are out there.

from Marianne Farag

Sam was my cousin on my mother’s side. We were seven cousins: six boys and myself; Sam was the youngest by roughly 15 to 20 years. The age difference meant we did not grow up with Sam. A further limit to our contact with him was the fact that we were living in different parts of the globe when Sam was born and during the early years of his childhood.

Several of those who have contributed to the blog have noted Sam’s talent as a teacher. Even as a little boy he demonstrated that talent. After I finished grad school I worked for a year for Sam’s late mother Nora who had a consulting firm – International Development Organization (IDO). Sam, then 13 years old, would come after school to IDO to help me with computer-related things like how to change the printer cartridge. He insisted that he would teach me how rather than simply doing it himself. In particular I remember the printer cartridge lesson given sweetly and good naturedly by him without a hint of condescension.

I moved back to Winnipeg to accept a job and during the many intervening years we lived our lives going on our separate journeys with our paths rarely crossing. One of the most notable memories I have of Sam as an adult is his wedding which stands out in my mind as the most enchanting one I have ever had occasion to attend! Initially I was apprehensive about going because apart from my uncle Shoukry and his partner Heather I did not know the other guests and wrongly assumed that with my liberal arts background Sam’s scientist friends would converse on topics that are completely inaccessible to me who has never figured out how to enter phone numbers of contacts on her cell phone and instead carries around a small address book in her handbag)!

Most thankfully I set aside those apprehensions and went and spent the week-end in Jacob, Ontario with a close-knit group of Sam and Meredith’s dearest friends and I remember thinking during the wedding event that there was just so much love in the room.

One definitely learns about a person through the company they keep. I was so glad to have had the opportunity at Sam’s wedding to meet and spend some bit of time interacting with Meredith as well as Sam and Meredith’s friends who struck me as among the finest people quite apart from their scientific or professional stature. They came across as interesting and more importantly interested, articulate, warm and genuine. Through my participation in his wedding, I came to learn how much my cousin Sam valued friendships.

While he and I did not have occasion to discuss them, in contrast to our other cousins, Sam and I shared certain life-defining experiences in common: we are both only children, we were both born in countries outside Egypt and both of our mothers died when they were comparatively young.

Arriving at a place of acceptance of events that we find overwhelming to fathom, and cessation of the searching mind that is hungry for answers, are entirely understandable challenges at this time; and yet, for Sam’s sake, I believe the greatest gift we can give him now is to release him in peace unconditionally, and to cherish the memories we have of our times together with him. How wonderful indeed that in such a relatively short life such as his, Sam managed to cast such a wide net in terms of his personal and professional impact. It leaves me very proud of him.

from Yoram Singer

Dear Meredith, Aya, Orli, Shoukry, family, friends, and colleagues. Sam was a stupendous researcher and a remarkable scientist. I would like to focus on Sam the mensch, Sam the man, the spouse, the father, the son, the friend of many people, young and old, the lighthouse to an incredible number of colleagues.

Meredith, Sam loved you with his entire huge heart, often calling you Mer with a sparkle in his eyes. When Dahlia and I first inquired about you, Sam proudly said that you have a Ph.D. in biostatistics. His lofty tone when he answered our questions about you stood in contrast to the humble tone he used when speaking about his own research. Indeed, he was low key when referring to himself, nonetheless, he was also the most animated and colorful researcher I have ever met. Soon after you and Sam settled in the Bay Area, I noticed that Sam often arrived rather late to Google. I had to use my interrogation skills in order to pull out minimal details. Sam disclosed that he had to spend a morning, here and there, with you at a doctor's office. Still, I did not hear a single complaint, and he always had an admiring and compassionate tone when mentioning you. He happily and wholeheartedly adopted your heritage, lighting Hanuka candles with us, celebrating Purim. Dahlia and I jokingly called Sam our honorary Jew. Sam was clearly the man of all religions, accepting and acknowledging any kind of spiritual ritual.

Aya and Orli, Sam was a fantastic father, loving, caring, warm, and a great teacher. You are too little to understand but you have inherited his enthusiasm and joy. Sam's family and friends will be next to you to help you grow into wonderful kids and joyful teens.

Shoukry, we have never met until the sad weekend, but I heard so much about you from Sam. Sam was no doubt your flesh and blood, a young version of your creative spirit. A while ago, Dahlia and I visited Meredith and Sam, and Sam told us a great story about you. You wanted to make a special dish but lacked the right pot for cooking. You thus went to the basement, where you keep all kind of tools, and spent a couple of hours building the perfect pot, rather than going to the store. The pot was then used once or twice... After hearing the story Dahlia and I had a big smile, and I said, "Sam, aren't you pretty much the same? Don't you have a similar mindset when you conduct your own research?". Shoukry, Sam loved you and admired you. How I wish he was less of a perfectionist.

As I wrote, I will leave it to others to write about Sam's brilliance and scientific achievements. Let me tell you a bit more about Sam's huge heart. Months ago, when it was clear that Sam was heading back to academia, Sam, Mark, and I had lunch together at one of Google's cafes. Mark was prickly as he was struggling with his project at Google. I was bitter because my initiatives seemed to reach a dead end. Sam was Sam, all positive. Do not get me wrong. Sam had his own share of frustration at Google. He designed, implemented, and (almost) launched a beautiful project only to see it hit a glass ceiling. During that lunch, I was pointing to all sort of faults and quirks while Sam was able to find a kind and positive angle to any issue I surfaced. Finally, Mark said, "Leave the kid alone, he is a genuine, sincere, goody two-shoes."

Let me finish with a true tale that symbolizes Sam to me. It was Google's "Bike to Work" day. Sam was riding his bike from San Francisco to Mountain View with a bunch of young engineers from Google, quite a feat. I saw Sam in the middle ofthe group of sweaty cyclists at the line to breakfast. I was post run, clean, dry, in long pants and a long sleeve shirt. The youngsters looked at me with a somewhat condescending look. Sam noticed it right away and said with a grin,"Look guys, Yoram likes to bend the rules, he 'Ran to Work'".

from Simon Osindero

I've tried to write this several times now, but the words somehow never seem right nor do they quite live up to the memory of Sam. He was awesomely warm, generous, kind, funny, brilliant; he had a really rare and amazing energy about him. Interactions with Sam so often left me feeling inspired -- to do more and become better -- both as a scientist and on a personal level. I feel very fortunate to have been his friend.

Sam and I first met when I joined the Gatsby Unit as a grad student back in 2000, and I was immediately struck by his tremendous friendliness, humour and warmth -- he was just great at making people feel naturally welcome and at ease. I have vivid memories of him presenting machine learning courses, and many tea talks and journal clubs whilst we were there. He had an uncanny ability to take complicated ideas, and convey them (excitedly) in such a way as to make them seem natural (and frequently funny). An iconic recollection of Sam is the way he'd come up to you with a gleam in his eye and tell you about the latest cool algorithmic trick he'd found out about; always genuinely happy and excited to share his knowledge. Then he'd proceed to explain the details lucidly and concisely -- often taking a whole paper or subject area and condensing it into a key insight so that you just "got it".

There are also loads of great memories from the many brunches, dinners, parties and random social occasions in London, Toronto, and of course NIPS. Consistently good times. And Sam would always make sure that everyone present felt welcome and included. He was as fun to be around socially as he was rewarding to interact with professionally -- which is to say extremely.

To Meredith and his family, my heart goes out to you. I find the events incredibly hard to process and so can only begin to imagine the pain of your loss.

Sam, you'll be missed dearly and fondly remembered. The personal and intellectual impressions you left on me, and on so many others, will ensure that even in death you'll live on in our minds, our work, and in our hearts.

from Laura Grego

I have been trying to remember the first time I met Sam, and I think it must be when he and Aaron came roller skating past my front door just after they’d arrived at Caltech. They were on a mission either/both to map the topology of the graduate student apartment pathways and to make friends. Or maybe it was to find out where all the single women lived, they were pretty cagey about their purposes. Whatever the intent, I was charmed and happy that Sam’s fun bus had arrived.

Sam was great at fun. I hope that David Hogg gets to chronicle here their determinedly legendary parties at Princeton. I think they tried to get every single ambulatory person in New England to attend, and even set up a travel fund to entice the more distant potential partiers. They “imported” turntables from New York, and Sam impressed with his B-Boy moves, which I assert here were awesome, and not just awesome for a scientist.

Though we were friends at Caltech, it was the few years after that I got to know Sam a lot better, as we ended up in the same cities for periods of time and went through some of the big life changes at the same time. Sam was lovely to have as a friend. As has been said here so much, he cast a glow and made you feel better and special, and somehow encouraged one to _be_ better and more special. I am grateful for the years that we were close.

Things turned out well with Sam around. When I moved to Cambridge (MA) Sam was going to help me start to get to know my city. We settled on the approach of just skipping the maps and getting on some buses and start taking them around Boston in our own random walk. This appears to be out of character for Sam who seems in other posts here to have “optimal strategies,” but that’s what we did. We ended up at a dusty fantastic Diagon Alley kind of bookstore full of old maps and communist propaganda posters, and I remember Sam getting totally engaged with the owner over some discovery he made and buying presents for people and promising we’d come back if we could figure out how we’d gotten there in the first place. Ten years later I still have no idea.

But he was so attentive to details, he probably did remember. He diligently made the effort to do the small things that build an intimacy and friendship, things most of us would forget to do as the moment passed. My friend Diana and I had him over for dinner once, and he was apparently delighted at my fake French accent reading of a Harper’s magazine article about Brigitte Bardot—he made me feel like I was way funnier than I actually am—and shortly after, a subscription to Harper’s mysteriously began arriving, followed by a note from Sam urging me to keep up my dramatic recitations. I met Diana for a drink after Sam’s memorial yesterday, and she reminded me about when I sent her (having never met him) to stay with him in London, and she recalled his excellent hospitality to a stranger; for example, he prepared her a choice of several colors for her “guest toothbrush.”

It was a couple of years later when Sam came back to spend some time at MIT, and he and I both were asking the same kind of big life questions. Sam was searching deeply to make the right decision about whether to take an enormously prestigious and demanding job at MIT or to return to Toronto, to probably a less stressful job where he could be near his family and friends. I was selfish at wanting him to stay in Cambridge and promised to fish him out of the lab and keep his social life going, but in truth I was really proud of him for making a choice that asserted value for both his personal and professional selves. I thought I shouldn’t worry about him because he was not just smart but wise.

I was weighing the same kind of decision about leaving academia to work on issues that deeply compelled me but are less valued professionally. He encouraged me to make this leap and believed that I would do good in the world this way.

Despite all of the other demands on him, personal and professional, and the ways of peripatetic scientists, he endeavored to maintain the threads of connection. It has been a few years since we’ve seen each other, but Sam was brilliant at remembering every year to say happy birthday, or just how does the day find you, when are we going to hang out? I remember when he wrote to tell me he was engaged and blissed out; strangely, it was the same day I was writing to invite him to my own wedding, though as it turned out Ahmed and I chose the same day to get married that Meredith was moving up to Toronto. Though we never got to meet each other’s “missing piece,” I was grateful that he had found what he was looking for, and continued to make steps toward a fulfilled life.

As so many have mentioned, Sam was so upbeat and positive, one might assume he was that way because he was so incredibly gifted that life was easy, but he like us all was not a stranger to sadness and uncertainty and the knowledge that we would at least occasionally fail as human beings. I think his joie de vivre and warmth and openness were a deliberate and brave and uncommon choice. Of all his considerable talents, that is the aspect of Sam I admired most.

I have been trying to sort out why my own grief at this news of Sam has been so overwhelming. Part of it is feeling the loss of someone so extraordinary and special. But also so painful is knowing that our friend’s awesome abilities to be positive somehow became depleted enough that for a moment he wasn’t able to extend the same kindness to himself that he unfailingly extended to us.

I hope that Sam’s friends and family, and especially his father and Meredith and the girls, find peace and I am sending my best wishes for that and for the girls to be as joyful in life as he was.

Sam, you were dear to me!

Laura Grego

from Abeer Alwan

I am very saddened by Sam's death.
I interacted with Sam a lot while he was a graduate student at CalTech and I was an Assistant Professor at UCLA. He was an 'honorary' member of my group, attending group meetings and classes, and was always in his lively, happy, and energetic mood. Everyone looked forward to his visits and provocative questions! He was an incredibly bright and kind person, and will be missed. Sincerest condolences to his family.
''Oh heart, if one should say to you that the soul perishes like the body,
answer that the flower withers, but the seed remains.'' K. Gibran

from David Pablo Cohn

Damn it, Sam - I still can't get used to the idea that I'm never going to run into you again, at the top of the stairs in B43. With that glint in your eyes and the smile that tells everyone that the universe has let you in on a beautiful cosmic joke, and you've just gotten the punchline.

All of us - we know that smile, and the enthusiasm with which you shared that joy. Damn. I keep looking down that hallway, still half expecting to hear your voice and see you come bounding around the corner again, hands waving wildly, showing us the trick in a way that, as Andrew said, "you couldn't help but understand." We all miss you terribly.

from Lawrence Saul

I hardly know where to start. Sam was a wonderful colleague and a dear friend. I had the privilege to work closely with him over a period of several years. I am terrible with details: I cannot remember exactly where or when we met, or even how we started collaborating. We were never in the same department and rarely in the same time zone. Indeed, at the peak of our collaboration, we were not only in different countries, but on different continents. Those unfavorable conditions were more than compensated by Sam's boundless energy and infectious enthusiasm. We used to joke that together we worked twenty-four hour days -- because when one of us was eating or sleeping, the other was working, and vice versa. Those were also the days before skype, and it was fortunate that I worked for the phone company because we talked almost as often as we emailed.

I learned so much from Sam. His mind was always racing with new ideas. He had high standards which I later inflicted on my PhD students. In papers and talks, every detail mattered; in research, he never settled for less than all-out effort.

Of course, Sam was not only a consummate researcher. He was also a remarkable person. He had a warm, broad smile and a constant sparkle in his eyes. He spoke alternately with passion and self-effacing humor. He could make a room of PhDs burst into laughter; he could also play gently with small children.

During our work on high dimensional data analysis, Sam and I experienced all the highs and lows that are part of any sustained research effort. In the spring of 2000, after months of flailing (which culminated in missing a critical conference deadline), we finally had our "Eureka!" moment. I have attached Sam's email on that day. I think Sam would approve: he loved to share the excitement of our field. I will always cherish the memories of our friendship.

From: Roweis@gatsby.ucl.ac.uk
Subject: *too* good
Date: May 17, 2000 4:55:40 PM PDT
To: lsaul@research.att.com

This algorithm is absolutely the business. You must call me if you are still checking email.

*Everything* I tried it on worked. I am running out of data for this algorithm to chew up! I almost want it to fail, just to be sure it isn't some kind of trick...

1) The 1D manifolds, of course.
2) I ran it on the translated faces, and it nailed it.
3) I ran it on Josh's swissroll, boom!
4) I ran it on the 8x8 digits and it gave good results, in fact just as good as the best runs I ever had with anything else.
5) I ran it on the 16x16 digits and it gave great results, although hard to display, so now I am working on the geodesic code. That way I'll be able to interpolate between any two items.
6) I ran it on a database of many poses and expressions of a single person's face, again great. Waiting for interpolation on that too.
7) I ran it on a short movie, with the frames shuffled randomly. I told it to learn a 1d manifold. What do you think it did? Bingo, it sorted the frames into the correct movie order (although sometimes it sorts them backwards!)
8) It is running on text now.

Too bad this didn't happen a week ago. It is *perfect* for NIPS...

from Brian Sallans

I met Sam in Toronto, and later knew him in London. A few memories: Sam explaining an algorithm using sandwiched, rotating overhead slides; Friendly teasing about my Canadian accent after a talk ("I'll tell you all a-boot it"); his incredible enthusiasm for everything that he did, professional and personal; telling a funny-yet-harrowing story about almost having his bike stolen while stopping to get late-night chips from the shop on Tottenham Court Road; explaining his rule for the youngest person one should date ("half your age plus seven years. Round down if you must."); giving me a few encouraging words after I gave a bad talk; Sam smiling happily while asking insightful questions during Gatsby tea-time-talks; Graciously letting me stay at his place when I was briefly stranded in Toronto.

Sam was a great example to everyone who knew him, of someone who could be so professionally accomplished, and at the same time simply a modest, funny, really nice person. He will be missed.

from Naraindra Prashad

I worked as the Financial Officer in the Department of Computer Science at the University of Toronto in 2001 when Sam Roweis joined the department. In that capacity, I would communicate with new faculty on a financial level (payroll, research grants etc.). I contacted Sam while he was still in London preparing for his move to Toronto. On the first few email exchange, my salutations to Sam was "Dear Prof. Roweis…..", until he finally wrote back to me saying "Please call me Sam". A few weeks later, a bubbly young man showed up in my office; shorts, t-shirt, running shoes and a backpack. With a large smile on his face, he said "Hi, I'm Sam Roweis....." and went on! I quietly thought, I agree with you, I couldn't call you anything but "Sam"! (smile). For the following four years that I remained in the department, it was always a delight when Sam would drop by the Chair's office. He immediately brightened up any room; he was a pleasure to work with and was a treasured addition to the department, and to the University. May you rest well, and may your beloved family be well taken care of.

Sincerely,

Naraindra

from Eero Simoncelli

I knew Sam for many years as a central figure at NIPS, and had only just begun to know him as a collaborator and friend when he moved to NYU.

Sam was a gem - as a thinker, as a colleague, and as a teacher. His first talk here, last September, was presented in a room overflowing with multi-disciplinary colleagues from departments throughout the university. Many of us sat on the floor, or stood out in the hallway, knowing that it would be well worth the discomfort. The talk was punctuated throughout with lively discussion, all ignited by Sam's brilliance, vibrancy and enthusiasm. Over the course of the Fall term, he came to quite a few of my group meetings, infusing each of them with that same boundless energy, penetrating and critical rationality, and the sheer joy with which he grappled with difficult problems. Even those who had never met him before were amazed and delighted by his spirit.

And from my brief encounter with the family side of his life, I have a clear image of him holding one of his daughters in our kitchen, showing her the clementines and various shiny utensils, and taking delight in her intent visual, tactile (and gustatory!) exploration.

I am grateful for the brief time I had with Sam. His death, so shockingly incongruous, has left me reeling. I hope we, his colleagues, collaborators, and friends, can find a way to understand it. Most of all, I hope that Meredith, and someday Aya and Orli, may draw strength and comfort from the affection we all felt for him.

from Nathaniel Daw

I never really considered Sam a peer – more of a hero, to be honest. I suppose, in general, that that kind of undisguised admiration could get in the way of a friendship, but Sam treated it, like more or less everything else, with grace and tact.

I first met Sam in '99; I was a new Ph.D. student in Pittsburgh but spending my summers at the recently launched Gatsby unit. Sam, as has been said here repeatedly, was a postdoc there, where he stood out both academically and socially among a group that was exceptional in both dimensions (really!). Some years later, as a Gatsby postdoc myself, I often had occasion to think back on his example, and to try (and largely fail) to emulate it.

In his scientific work, I think Sam viewed himself as sort of a craftsman: collecting powerful tools, dissecting them, refining them, and applying them in new ways. He would speak modestly about this – once explaining that he had never written a proof, except insofar as he inherited the theoretical guarantees that were inherent in the tools themselves – but at the same time he believed strongly in this approach and was so clearly excited and driven by the possibilities of his toolchest.

That Sam’s work and his thinking were so grounded in this concrete, almost clockwork perspective was one reason that he was able to be so incredibly effective at communicating about them. Many of his memorable turns of phrase (which many of us have swiped) are also so physical: the goal of LLE was to build a “box” with “knobs” that would dial along the key dimensions of the input space; HMM algorithms could be described as involving “bees” flying between states, linear models as operating on “pancakes” in higher dimensional spaces. Although he made this, like everything, look effortless, Sam worked incredibly hard at developing the tools for communication much as he did for the research itself. Over the years, I remember watching him experiment with different presentational innovations. In the days of overhead projectors, he would construct sandwiches of multiple transparencies and slide them over one another to make animations. Once, he started his talk with the key to an elaborate color-coding scheme for his slides; my favorite was brown for statements that weren’t quite technically true: you could ask about the caveat afterward, if you wanted. One year, he discovered that if he laminated his NIPS poster, he could write on it with a dry erase marker. He took a great deal of pleasure, not just in the didactic possibilities of this, but also at the look of horror on the audience’s faces the first time they saw him whip out the marker and start scribbling all over his figures.

Much more important to me – though much harder to describe, and more painful to recollect – are Sam’s personal qualities. As others have mentioned, Sam served a sort of guide and provocateur for a group exploration of London’s nightlife (also the somewhat less adventurous nightlife of Whistler, BC, as others have wholly neglected). My first encounter with Sam’s legendary generosity was the way he would subsidize the graduate students' food and drink in our London outings – although he explained that this was a remnant of his socialist Canadian upbringing, I only later realized he was trivializing a fundamental trait of his character.

It was a pleasure and an honor to watch Sam grow up, always many steps ahead of me. Some steps were small. When he took his first faculty job, he decided that he really should no longer engage in his annual “NIPS flirtation” with a PhD student. Typical of his sometimes untethered spirit of sharing, he told me this by way of trying to set me (not yet faculty) up with the student in question.

Our final interactions all centered around the much bigger steps of family and fatherhood. Like so many of my colleagues, I was excited about all of the professional possibilities from Sam’s arrival at NYU. But as it happened, his arrival – to an apartment in our building – coincided closely with the birth of our son, so I saw little of him (or anyone) at work. Instead, Sam and Meredith were instantly and immensely helpful and thoughtful, repeatedly showing up unexpectedly at our door with various bits of advice and baby equipment we didn't yet realize we needed. Sam always patiently explained what each object was for, our son is now surrounded all day by Sam’s things.

Sam aspired to fatherhood before I realized it was something to aspire to, and it’s the calling that all his talents really point to. If I had to have a last experience with Sam, I am glad, then, (though “glad” is not really the word for somewhat less devastated) that it was this one. And if I have one regret that tops all the others, it is that I will never get the chance to learn more from Sam about how to be a father, as he perfects it all a few steps ahead of me; and of course that Aya and Orli, and Meredith, will not be able to enjoy his continued success at what, I am sure, would have been the thing he was most brilliant at of all.

from Michael Jhu

Sam and I were in the same high school class at the University of Toronto Schools.

Words simply can not express the immense respect that I have for Sam, who remains to this day the single most brilliant and caring person I have ever had the good fortune to meet. Perhaps my esteem for him can best be expressed by the fact that even though we hadn't seen each other in nearly 20 years, his tragic death has touched me and saddened me so profoundly.

"Shouks", my deepest condolences go out to you and to all of Sam's family. As a father myself, I can't even pretend to imagine how painful this must be for you. May you draw strength and comfort from knowing that all who knew Sam, even those of us who only knew him half a lifetime ago, shall be forever the better for having had that privilege.

The world has lost one of its very finest.

from Tony Bell

There's no way to really digest this news about Sam and hard to believe he is not alive. This was a guy who
was so alive to you every time you met him. He had me off in whirl of ideas within seconds of meeting him 13 years
ago, and even the last thing I ever heard him say: "I feel like an email input-output node" seemed to capture something else perfectly. I'll miss that guy.

from Sven Dickinson

The day Sam joined our department at the University of Toronto back in 2001 was a very special one for me, and during this tragedy I'm only now beginning to understand how special that day really was. I clearly recall how excited we were after his interview talk, and at the prospect of his joining us. When he arrived, his impact was immediate. Just being in the same room with him seemed to brighten any experience, whether it was hearing his honesty at a faculty meeting, his insightful questions during a talk, his own fantastic lectures and seminars, or the energy he injected into any social situation. Losing Sam has made me realize that I've met very few people in my life that have that special kind of impact on everyone and anything they touch. It's an extremely rare combination of being incredibly talented, incredibly generous, incredibly zealous, and incredibly enthusiastic -- but I'm sure there are other (incredible) ingredients to Sam that set him apart even further.

Sam touched me personally in a number of ways, a couple of examples which I'd like to share. When my son, Kiva, was considering attending UTS with some trepidation, Suzanne and I asked Sam if he could speak with him and share his own UTS experience. Sam's impact on Kiva was immediately profound, and witnessing Sam's passion and enthusiasm about the place changed his entire outlook on the prospect -- and hearing it from a guy that was infinitely cooler than his parents will ever be didn't hurt either. Kiva attended the school, and it was as wonderful as Sam said it would be. Although their paths would cross only occasionally over the next 6 years, Kiva was forever touched by Sam, and is feeling the same kind of hole the rest of us are. How precious are those that can affect us so deeply in such short a time. My other anecdote surrounded a decision I had to make as a committee chair on a particularly contentious issue. From his sabbatical in California, I received an email from Sam that meant so much to me. He sensed from afar how difficult the decision was for me, and through his incredibly kind and supportive words, lifted me from a state of feeling really discouraged to feeling like I'd done really well. I'll cherish his empathy, thoughtfulness, and sensitivity forever.

As I struggle forward with this, one thing is becoming very clear to me. And that is how incredibly fortunate I've been to have crossed paths with Sam. He's set an inspiring example for me of how to be a scientist, a supervisor, a teacher, a husband and father, and perhaps most of all, how to touch the lives of those around us. That inspiration and that example I'll carry with me forever.

from Michael Jordan

I've tried several times to sit down and write a few words about Sam but each time my head starts spinning and I've stopped.

Some recent memories of Sam include him and Meredith on the terrace of my house in Berkeley---it was a party for my research group but somehow it felt natural to invite Sam as well---and a long run on beach in San Diego---we ran for what seemed like forever to me and then I stopped and Sam kept running for a while longer.

I had a lot in common with Sam and I believe that he felt similarly. Both of us had a love for probability and for mathematics, especially the kind that could be explained in a few minutes to someone before their eyes start to glaze over. The kind of mathematics that was fun to discuss over a beer (well, a beer for me; Sam didn't need a beer to take his enthusiasm and joy up a notch). Both of us had a contrarian streak.

This similarity in outlook made me prize being able to run into Sam on a regular basis; I loved getting his take on new developments. When someone whom you basically agree with sees something a bit differently than you do, it's a great chance to learn something (perturbation theory, right Sam?).

Sam, my head is starting to spin again and I'm going to have to stop thinking about how much I'm going to miss you.

I continue to love being a part of the machine learning community, mainly because it brings together so people whose principal passion is a love for ideas, especially new ideas. They're friendly, but fierce, they're wise, but young. Sam was perhaps the paragon of this intellectual movement.

Sam, forever young.

from Bill Freeman

Even though I only knew Sam through conference interactions, and then through his stay at MIT, I always felt he was a special friend. I loved to talk with him; he was always upbeat. He would cheer me up, if I wasn't, and get me excited about some new thing that he was excited about. We collaborated on one paper, the result of one such conversation.

His lectures were delightful; he was informal, enthusiastic, and always clear. He would show the audience something simple and
elegant, that in hindsight was clearly the right thing to do, although beforehand we had no idea.

A long review of a Neural Computation article that I co-authored ten years ago ended with "Good job, guys!". It reveals my image of Sam that I've always assumed those words were from him; it's the kind of thing he would say.

I've appreciated reading the other postings by his many friends. My heart goes out to Meredith and to all of Sam's family.

from Michael Overton

I have just returned from the incredibly moving memorial for Sam Roweis that was held this afternoon [17 January] in New York. Everyone who spoke, including Sam's wife and his father, was amazingly warm, coherent, thoughtful and sincere and there could not have been many dry eyes in the room. We in the CS department at NYU are devastated by this shocking loss, and our hearts go out to his family and friends left behind. I did not know Sam well, but well enough that I was already very fond of him and well aware of his potential for enormous impact on our department. With his infectious enthusiasm, great sense of humor, broad interests, thoughtfulness and common sense, he already played a major role on our department even in the short time he was with us. We will miss him tremendously.

from Cayle White-Hasson

I attended University of Toronto Schools with Sam for six years, from ages twelve through eighteen. Sam was a superstar, known and liked by all, and everything he touched seemed to turn to gold. It seemed effortless, although I'm sure quite a bit of effort went into it. In a nutshell, to me he was like one of the Muppets. He wore these long sleeved, striped polo-neck jerseys, that nobody should be allowed to wear past age six but it suited him. He was completely unselfconscious. And he had a style all his own. He also bobbed along like Kermit the Frog in one of those "breaking news" flashes. Some days, he would get so excited about some new phenomenon that his eyes would practically bug out of his head!! He was always so kind and complimentary to me. Even as he watched me doing something that he probably thought was reckless; or when given some assignment that he could complete in his sleep that would take me ages to do, he was never arrogant or judgmental. I never thought that I would be attending a memorial service for Sam at this point. Although I hadn't seen or spoken to him in years I figured he was out there somewhere, happy and very busy. I wish all the best to his father, Meredith and the girls. And for them to know that I am always at their disposal to talk about Sam anytime they wish.

from David McMillen

My memories of Sam all cluster around a sound, "HA ha ha!": that shouted burst of laughter he let out when he saw the humour in something in this world, as he so often did. I can't believe that this sound has been silenced. We'll miss you, Sam.

from Dan Lee

I came back from the memorial service for Sam at NYU moved and touched by the memories of so many of his closest friends and family. Everything was an adventure for Sam, one to be shared with his ever growing band of brothers and sisters. Whether it was machine learning research, rock climbing, snowboarding, or partying, he was always ready to try a new trick and to give a hand to a novice like myself.

Sam, your scientific work showed us how local interactions could give rise to global implications. You gave us such joy as individuals, and also brought us closer together as a community. You will be forever missed, and we will not forget the young family you left behind.

from Mike Titterington

In 2008 there took place a six-months research programme at the Isaac Newton Institute for Mathematical Sciences in Cambridge, organised by David Banks, Peter Bickel, Iain Johnstone and myself. One of our main objectives was to stimulate interaction between people who would call themselves statisticians and people would be more used to referring to their activity as machine learning. Sam Roweis was near the top of the list of those from the latter community whom we hoped would participate and we were delighted that he was able to spend some time on the programme.

Our reason for inviting Sam was 'merely' our knowledge of the important work that he had done. I for one had not actually met him, and I have to say that I was taken aback by the personal characteristics, namely dynamism, sociability, kindness and general 'nice-ness', that complemented his obvious creativity and enthusiasm for his work. He entered into the spirit of the activities in the Institute and tried hard to persuade us to incorporate the sort of 5-minute spots referred to by David MacKay!

I only encountered him for about a month and yet his departure seems to have left a massive gap.

from Hagai Attias

My first memory of Sam is from a workshop in Toronto. He came up to me after my talk, which I wasn't sure was successful as I saw eyes glazing over 15 minutes in, and said, emphatically and excitedly, it. Kicked. A**! This from a complete stranger immediately brightened things up. His own talk, and his other ones I attended since, were for me masterful tutorials in the art of presentation, both formal and informal. We overlapped at Gatsby; scanning through some of the postings here brings back the magical year I spent in London, where you'd go to a chemist for Advil, and where Sam and others awoke my inner Bayesian (I remember wondering, working at the office on Sunday afternoons with only a few people around, where everyone else was... Lazy Dog with Sam, mystery solved). After I moved to Microsoft Research, Sam's works on single microphone source separation and on locally linear embedding came out, making it seem the real fun at Gatsby was just beginning. A year or so later MSR offered Sam a position. We had dinner in downtown Seattle when he visited, and I said I wanted him to join me there. I remember writing a glowing review of his work for the interview loop and highlighting his recently published Science paper in red. Alas, Sam turned us down to go back to Toronto, and the fact he did the same to MIT was only a small consolation.

What made Sam special to me was a shared passion for machine learning in audition, which was relatively rare. As I was developing new algorithms post MSR, I remember having in the back of my mind this thought: one day, soon, I'll meet up with Sam and tell him about them, and we'll have an awesome, totally unpredictable conversation. Then time suddenly leaped ahead... one day we'll be able to run a model on his lecture videos and research papers and play his part of that conversation. Sam, I wish you could be around when we do this problem, that would make it so much fun.

from Yee Whye Teh

Sam was just larger than life in every respect, and a hero to so many of us. In addition to his brilliant scientific achievements,
what really strikes me most about him is his thoughtfulness, generosity and abundance of life. Sam inspires my faith in humanity when the world sometimes seems like a crazy place.

I first got to know Sam when we were both at Gatsby around 1999-2001. Afterwards Sam, Geoff, Max and I returned to Toronto more or less at the same time, so I was lucky to spend a year and a bit more with him.

I was fortunate to have worked with him on a number of papers and experienced Sam's enthusiasm and energy "behind the scenes". The way he motivated a grad student as myself and infused so much fun and excitement into the work was inspirational and one I aspire towards (never as well) ever since.

As many people have said, Sam has the most generous and selfless spirit. When I was applying for faculty jobs, the whole process seemed so incredibly daunting, so I asked various people for help and advice. Sam wrote me this amazing frequently-answered-questions list, like ten pages or something, detailing every step of the process, and all the little things you should watch out for, how should you pitch your talks, the politics within a department etc etc. It was awesome and really helped cool my worries and boost my self-confidence about being able to handle the whole thing.

I am little bit of a foodie so I have a few food related memories of Sam. Once we were having lunch at the tea room in Gatsby and Sam started applying peanut butter on his bread then slicing pieces of banana onto it to make a sandwich. I thought it was a little disgusting at the time but Sam loved it, saying how bananas have so much potassium and it's good for your brain. I tried it years later and it was great! Another time, we were at his place for brunch (this cool little apartment on the top floor of a converted house) and he made smoothies for people with this handheld blender.I thought "how cool is that!" and a handheld blender is indispensible in my kitchen ever since. Sam was the one who introduced us to chicken escalope at The Onion. I still go there once in a whilefor the chicken escalope on a brown bap. I'm happy to report that it's still as big as ever and enough for lunch and dinner!

Although these aren't really characteristic of him, they are fond little bits of memories I have of him, like the boom of his voice or the way his hands gesticulate, or the way he bounces towards the whiteboard in the midst of a discussion.

Sam, thank you for your warm friendship, I'll miss you.

from Simon Lacose-Julien

In addition to his academic brilliance, I will remember Sam for his genuine human warmth and his contagious energy.

Apart the usual NIPS parties, I remember this time with Sam when he was sitting in the back of our practical machine learning class taught at UC Berkeley in early 2008. Not surprisingly, he could easily blend with the other graduate students -- he was so accessible. We chatted a bit after the class about his current and past projects. He would preface them by some humble disclaimers that he "is just toying with things", nothing grandiose, but then would passionately talk about his ideas, with such energy that you couldn't stop yourself but join him in his enthusiasm. I was surprised at the time by his academic modesty, given how he was shining as an academic star. While talking about his future plans (would he stay in the Bay Area? would he could go back to Toronto?), his family would always seem to come up as the highest priority. We exchanged a couple of emails afterward about a possible visit I could make to Google. And in each exchange, I could feel his genuine human warmth. At the time, I actually had to make a big decision about my post-doc plans, and he selflessly offered that I call him if I needed advice about the different places that I was considering. I am actually quite thankful for the guidance he offered at the time.

I am still in shock with the tragic news. Sam was not just a brilliant researcher, but he was also an amazing person who would leave his positive mark in the people's lives who would be fortunate enough to cross him -- as the many posts below testify. I send my most sincere warm thoughts to his wife and two daughters -- there are no words to describe something like this. I would also like to echo Andrew McCallum's thoughts on the importance of the human dimension in our research community. Even away, Sam could still be building our community...

from John Lafferty

Sam embodied some of the best traits of the research field of machine learning. He was open, inclusive, and had a wonderful energy, enthusiasm and excitement for ideas and research developments. He was articulate and clear, with a gift for inspiring people about ideas that he thought were cool -- not just his own.

When he visited CMU a while back, Sam suggested having a joint CMU/Toronto machine learning get together, a great Sam-esque idea that unfortunately never happened. I worked with him to put together a proposal for discussion articles in the Journal of Machine Learning Research. Sam saw a bigger picture, a bigger community, than most of us. His intellect, charm, enthusiasm and energy contributed tremendously to making our field so vibrant.

from Michael Kearns

I think I am one of perhaps hundreds of people who has not spent a great deal of time with Sam, yet considered him a friend, because of his warmth, humor, and infectious enthusiasm. I vividly remember the time he came up to me after a talk I'd given at UAI in Acapulco in 2003. I was flattered that he'd enjoyed the talk despite it being on topics distant from his own, and then impressed by the insights in the questions and comments he posed, all with a kind of sparkle of fun in his eyes... Just the demeanor of someone enjoying what they do immensely, with the ability to make you more excited by their energy.

The fact that I was not among Sam's many close friends, not a direct collaborator, probably helped make me a good choice for one of his letter writers for his move to NYU. That letter begins with the sentence "The preview is that Sam is one of the very best machine learning researchers active today, and certainly one of the stars of his generation; any department would be fortunate to have him." The middle of the letter discusses his work with Lawrence on LLE and remarks "If I were asked to identify just a few pieces of work as being among the most important in the field of machine learning in the last decade, this would certainly be on the list". The conclusion states "You should get Sam if you can."

Indeed NYU was fortunate to get Sam... and as I spend a lot of time in NYC, when I learned he was going there I was excited to think I might see him more often, professionally and socially. Like too many things in a busy life, I waited too long.

Goodbye Sam... it's clear from the posts here that you'll be remembered with limitless affection.

from Andrew McCallum

I met Sam in the 1990's at NIPS. I was relatively new to the community, and a little overwhelmed by its size and scope. The gregarious and well-connected Sam took me under his wing and made a point to invite me to lunch with a group. Although he was younger than me, I often thought of Sam as a mentor---so many of us wanted to be more like him: he was brilliant, creative, warm, funny and the most enthusiastic collector of algorithmic "gems"; he was also a generous community builder.

In 2000 Sam worked for a summer with us at WhizBang Labs in Pittsburgh. In the midst of the constant push and pressures of a start-up company, Sam was a breath of fresh air. Bubbling with ideas, he engaged with everyone from fellow researchers (like Fernando Pereira, Tom Mitchell, William Cohen, Drew Bagnell and Jonathan Baxter) to software engineers and sysadmins.

After I moved to UMass Sam visited several times. Three memories stand out.

Sam had just finished giving a delightful hour-long talk on Neighborhood Component Analysis to an audience of about 70 people. Many researchers might have been a bit tuckered out after making such a presentation, but Sam was still going strong, answering questions from a group of graduate students that had gathered around him afterward. When we realized that there was an hour-long hole in his visit schedule, he suggested that the ten of us stay in the room and continue talking together. We wandered over to a whiteboard, and the discussion ranged more broadly, eventually arriving at the relation between Bethe free energies and belief propagation. Sam proceeded to give an impromptu lecture on the subject---his gesticulating hands drawing pictures in the air, equations flowing out of his blue pen---all so clear, so beautifully motivated, unrolling as naturally as a fairy-tale. (One of the other blog writers had the perfect turn of phrase: "you couldn't help but understand" when Sam was explaining something to you.) Sam also pulled everyone into the conversation. In true Socratic fashion, each stage of the mini-lecture was driven by questions which Sam would ask the students (directed to the student by name, because Sam had taken the time to introduce himself to each student and learn their names). Somehow Sam's boyish enthusiasm prevented even the most junior students from feeling too self-conscious. At the end of the extra hour the students were filled with the sense of "belonging" that came with this new knowledge, and with Sam's infectious joy in it.

That weekend Sam stayed at my house. Unnecessarily, but totally characteristically for him, he brought gifts---a book for each family member: myself, my wife and two children. I can still see Sam sitting on the living room floor cross-legged, the small body of my four-year-old nestled in his lap, while Sam read aloud.

We had made plans to go sailing together on Saturday, but there was no wind. We decided just to spend a simple afternoon at home. I remember walking out on to the porch seeing Sam sitting there, feet up on the railing, eyes closed, face toward the sun. A quiet moment. Relaxed.


In 2007 I was asked to be program co-chair of ICML. I was going to beg off until I understood that Sam would be my co-chair partner. There is no one with whom I'd rather take on such a job. Sam and I became like climbing expedition partners---taking turns hauling the supplies, calling out advice about where to drive in the next piton, encouraging each other. He brought his creativity and boundless energy to this service task. I count literally over 1000 email messages from Sam during our 8 months of ICML work. Sam wasn't able to make it to Helsinki---his twins were born soon after ICML---but Sam's imprint is all over ICML 2008, and he initiated multiple innovations in the conference that are on track to persist for many years to come.

Sam, we miss you terribly. Know that you are loved dearly.

Meredith, I'm sorry we haven't met yet; I wish you peace, strength and courage. Reach out to Sam's friends, and we will be there for you.

For me the tragedy of Sam's death really brings to mind the value and importance of the personal connections we have in our research community---the enduring friendships, the caring, the human dimension beyond our research---and how much these friendships mean to me and all of us, even though we are scattered across the globe. Our grief over Sam's loss brings us together, and will deepen and strengthen our relationships. So, although we desperately wish Sam were here with us instead..., from the beyond, Sam is still building community.

from Yaser Abu-Mostafa

I first knew Sam when he was a student at Caltech. He already had all the ingredients that make him loved and admired by so many people today. Brilliance and ambition are not rare in our circles, but with Sam they came with genuine kindness and an unfailing positive attitude. I am so sad that the life trials he faced were severe, and that I could not detect the pain he was in and maybe show him the same kindness that he showed me when I had a personal loss years ago. It was a joy to spend time with Sam, and it was a joy just to know that he was around. Rest in peace, my friend.

from David MacKay

One of many joyful memories of Sam is the tradition he invented of giving presentations in the style of a cinema. He would precede "The Feature Presentation" (which was, say, 45 minutes long) by a 5-minute "Short" on a different topic, for example some neat algorithm he had picked up recently and wanted to pass on.

Sam also initiated a tradition of entertaining the community, usually at holiday-time, with well-chosen puzzles, some of which I am still chewing over. Here's a message from Sam.

From: Sam Roweis Wed Aug 6 00:22:26 2003
To: learnmeet@cs.toronto.edu
cc: "David J.C. MacKay"
Subject: coin puzzle

Here's a summer coin flipping puzzle to keep you occupied:

"You are given a biased coin, whose bias you do not know.
Using a sequence of independent flips of this coin, simulate
a sequence of independent flips of a fair (unbiased) coin."

The goal is to do this as efficiently as possible, in the
sense that you use as few flips (on average) of the biased
coin per simulated flip of the unbiased coin.

Here's an inefficient but correct way to get you thinking:
Flip the biased coin twice. If it comes up HH or TT, try again.
If it comes up HT, output H.
If it comes up TH, output T.
Of course if the bias is near 0 or 1 you will be rejecting a lot...

Sam, you were a wonderful, wonderful colleague and friend. Life was always filled with fun and humour and interest and intensity when you were around. We will miss you terribly, but you are not gone - you are still with us now, in the memes with which you have infected us.

from Erik Winfree

Like for so many of the people posting here, Sam was an inspiration to me. Someone who knew what it meant to be a good person - in heart and in mind - and had the will to do it. I miss him so much.

I met Sam in graduate school, when we were both in John Hopfield's group. It was an amazing time. We were all young, learning what it was to be a scientist. Sam delighted in the process, and delighted in reminding people of the joy of having so much to learn. In my mind, I can still hear him saying, "Ah, young butterfly, haven't you heard that the trace of the matrix is the sum of the eigenvalues? Let me show you why..."

He took such joy in seeing people understand - in seeing people happy, for whatever reason. He loved sharing intellectual jewels the way some people love telling jokes. We'd seldom see each other without his telling me about the latest mind-bogglingly beautiful result that he was enamored of. Maybe this week it's Propp & Wilson's exact sampling from markov chains, with applications to tilings, explained enchantingly in terms of a time machine and living backwards. And if I was too slow to catch the explanation in real time (I usually was) then it wouldn't be long before I'd get an email from Sam, spelling it all out in detail.

Sam loved sharing himself to make people happy. He was a people person. I had never heard of the phrase, "people person", before I met Sam - and if I had, I wouldn't have thought that a people person could also be a deep intellectual. Doesn't deep understanding entail privation and solitude and a retreat from the softer emotions? But knowing Sam disabused me of that conceit.

He was also perfectly willing to demand something of people - if the demand came with caring and love. Like the demand to take care of the world. Another concept Sam introduced me to was dumpster diving. But not dumpster diving as a cheap way to fill your fridge with perfectly good food the supermarkets were throwing away. Rather, it was clear he was talking about dumpster diving as social activism in protest of our society's wasteful ways. That, and the cup hanging by a carabiner from his enormous backpack.

I don't know if I've met anyone else who had the goodness of humanity so deeply embedded in his heart.

We'd have discussions about the future of society in the wee hours of the morning. Sam wasn't afraid to see that our world is changing, and that we should prepare for it - no: that we should take a role in guiding it for the better. I remember talking about the ever-increasing presence of surveillance cameras and email snooping and Big Brother and how it scared me, and Sam countering by explaining why he strived to live a life of openness with no secrets and no shame, because he saw the only solution being to prevent the government from being the ONLY ones with such pervasive knowledge; everyone must have access to the same information, so we must learn to live wisely in a world with no secrets and no privacy. That made me think, for a long time. I was surprised by his conclusion, and also surprised by his confidence that he could live a life so clean, so pure, that with no privacy would come no shame. I think he always strived for that kind of purity of feeling.

Many of my memories about Sam come from our time working together in the early days of DNA computing. When Paul Rothemund and I came back from the first conference on DNA-based Computers flushed with excitement, Sam joined us in the adventure and soon the three of us were meeting every week or so with Len Adleman and his friends at USC. We would have wide-ranging talks about life and science on our long drives to and from Len's lab or home. Sam was irrepressible, stripping our ideas down to their simplest and cleanest essence, suggesting new possibilities and new ways of looking at things, breaking our mental roadblocks with his insistence to understand: "Why?" and "Why not?" And always he would urge us on with his enthusiasm, or buoy us up with wise words when we were discouraged, overwhelmed, or depressed. (I sure could use a dose of Sam right now.)

To Sam, science was personal. So anyone could do it. With whatever was handy. Of such spirits was born the Sunday Experiment Club, with the charter to think about and do something unrelated to our thesis research every weekend. Alas, we only met twice - but the inspiration remains, as do memories of trying to move fluorescent DNA around in a puddle of saltwater by means of a 9V battery and two electrodes.

Of course, we all know that DNA computing wasn't Sam's destiny and it wasn't his true passion. I guess it was a hobby - a chance to drink more broadly of the scientific experience. And also sometimes I wonder if he did it just to be with his friends, us... maybe it was as much fun for him as stealing a city transit bus for a scavenger hunt? I don't know how he managed to squeeze it all in between writing "EM algorithms for PCA and SPCA" and "A unifying review of linear gaussian models". Sometimes I felt guilty that our collaboration took so much of his time away from his true passion. Perhaps more surprising is that at times it seemed that only his friends could see that machine learning was his true passion, and we had to convince him not to give up on it when he was afraid he would have nothing great to contribute.

One wants to remember Sam as a shooting star, blazing through the night sky with inspiring purpose and direction. But it wasn't always so. Like any mortal, at times Sam grappled with finding meaning and direction in his life. He seriously wanted to be an astronaut, for example, and was torn by the thought that being an expert in machine learning was not a ticket to the sky. What I admired so much about him, though, was how he never stopped thinking about what life meant, what principles to live for, how to do right by others - whether or not he knew any answers. He was a serious and sincere person in the most fun-loving way.

Sam loved to entertain us with stories, too. He had a lot of them, each delightful. Here's one, as best I remember it: Halloween. Sam's a young kid. Dad wants to make him a real special costume. 1 raincoat. 1 umbrella. 1 leaky "cloud" on a stick. Attach above umbrella. 1 basin for collecting water. Install around legs. 1 water pump, battery powered. Place in backpack, route tubing from basin to cloud. And little Sam walks from house to house with a rain cloud over his head! What fun!

P.S. For the geeks out there, I'll include one of Sam's signature files from grad school days.

from Judy Yanowitz

How do we measure a lifetime? And its loss?

Sam was a refreshing change to the doldrums of my last year of Princeton. We met, I recall, in the lounge of Guyot/Moffett, one afternoon after one of his clearly infamous catnaps, when I introduced myself to this new guy hanging around. From what I gather from other people's writings, that might have been the one time someone preempted him on an introduction. We became fast friends and talked about books and careers, hope and dreams.

I remember walking with him in the institute woods and having dinners at his small cozy apartment. But most I recall an afternoon, just before I left Princeton, sitting on the bridge over Carnegie Lake, the sun shining. I remember Sam commenting how Harry and I were "perfect for each other" and how he was looking for that (and later, I remember hearing of Meredith and being grateful he found that). I recall him telling me I would succeed, as if it were a given fact and believing it, because Sam said so. He was convincing. And made you believe in yourself.

We went to visit in London, but he happened to get his interview at MIT the same week. He let us crash at the apartment anyways. On his return, he asked, "As MIT alums, is there any way you would believe that I can say no to MIT?" And how much he wanted to go to Toronto to be near his Dad and old friends and do work without the stress of the MIT name. He let us sleep in his bed. He brought us to the best vegetarian Indian restaurant, what seemed like miles and hours away, but worth it. We bought the cookbook and every time we make a dish-- all profoundly delightful-- I think of him.

We lost touch, sort of. Not sure why. Of course, a regret. But, a reminder to cherish what Sam gave me: belief in myself, joy in short walks, the desire to connect to people even in brief moments, the ability to dance with abandon. To Meredith and family, my deepest condolences. May the light that Sam gave us all give you strength to go on.

from Michael Hochster

When Sam started at Google in early 2007, I was assigned to be his mentor. It didn't take long to figure out who the real mentor was! I remember telling people that Sam right away understood anything I explained to him better than I did myself. One evening after work, Sam and I were talking about some technical topic while I waited for my bus home. I don't remember the details now, but at the time it was captivating enough that I didn't notice the bus loading, then pulling away. Sam chased it some distance on my behalf, yelling very very loudly until the driver pulled over. That was Sam: engaging enough to make you miss your bus, kind enough to flag it down for you. I'll miss him.

from Dave Blei

In these last few days, my most vivid memory of Sam was a bike ride we took in Pittsburgh on a humid night in 2001. We stopped and sat on a bridge---Pittsburgh has many---watching the crowds and lights of a baseball game at the stadium across the river. It was a simple and insulated moment, the kind that Sam appreciated and showed his friends how to appreciate.

The writings here are testament to Sam's inspirational enthusiasm, intellect, and humanity. We will miss him.

from Chris Daniel

I still remember the first day I met Sam. It was in the August of 1990 and I had attended an Engineering Science “get together” and information session with my best friend for all new frosh that were going to be starting their undergrad in September. Sam was also one of those Frosh. His winning smile, easy-going nature and infectious personality were a quick hit with us and, after the meeting, the three of us went to Harvey’s for lunch while Sam amused us with a few “magic” tricks that he had recently learned. During our first year of Engineering Science, Sam and I were both part of a very tightly knit group of about 10 engineering science students who all lived at the New College residence. It was during these study sessions that he quickly (and justifiably) earned the title of “God” from many of us who were in complete awe of his academic abilities, especially when you combined them with his incredibly giving and humble personality. And how many “cat naps” did he take on our sofa!?!?!? He had the ability to sleep for 45 minutes and wake himself up COMPLETELY refreshed to take on the next challenge... I also recall that whenever we would go for a walk through downtown Toronto, we would CONSTANTLY pass people on the street that would hug him warmly and ask what he was up to these days... Even though he was only 18 at the time, he had clearly touched many lives in an extremely positive way.

After our first year, about half of the group (myself included) split into a variety of other engineering disciplines. However, the bonds we all made in that first year were very strong and we continued to socialize throughout our undergrad. Our group even celebrated a 10 year graduation anniversary in 2004 at which I recall Sam had to fly to Toronto in order to attend.

That was the last time I saw Sam.

How to summarize my feelings? I’ve respected and admired him for 20 years. I have proudly mentioned him in hundreds of conversations to people that have never, and will never meet him...

I wish I could have shared with him that I am also a 38 year old engineering professor who my students call “the energizer bunny”.
I wish I could have shared with him that I am also married with a 21 month old daughter who I adore and yet she can stretch my limits like only your child can.
I wish I could have shared with him that our lives appear to have become more similar in some ways over the last few years...

But, most of all, I wish that I could have held him back and reminded him of the title of a song that I wrote and sang for him (and am currently holding in my hands) in our second year when his mother had died and he was becoming introverted in his grief... “There’s more strength in two”.

I’ll miss you Sam.

from Matt Beal

You know the way they say that postdocs are the lifeblood of a research group: they have the skills, but they also have the time that professors don't have, and you'll learn so much from them. That was the case when I met Sam, he a prized postdoc at the start of Gatsby and me and Sham the first students there, eager to learn. I'll never forget the way at tea-talks Sam used to sit close in and sometimes run a coin over his knuckles, back and forth, back and forth. He did it to catch your attention as you spoke, and to prove that he could think hard about your work and play at the same time. I remember clearly the first thing he taught me --- relating to identical eigenvalues in inner and outer products of a data matrix --- the observation was simple but the application extremely useful, and the event stood as a template for what I and many others would receive over and over again in the coming years.

I happened to follow Sam to Toronto and ended up working in the office right next door to him every day. He was the happiest I've ever known him. Like an uncle he helped Cassie and me move into our little apartment, warmed to Cassie immediately (or maybe that was the other way around), and always checked that I was busy with work, bouncing ideas off my whiteboard. We would mischievously conspire about how to encourage Radford to submit his Embedded HMM work to NIPS, and get the inside scoop (appropriately anonymized) on the latest reviewing scandal in one of the many committees he sat on. One day he overheard Cassie and me talking about somehow taking a trip to Niagara and just walked in and said "You know what, Matt: you kids need to take my car for the weekend. I'll be back Tuesday", and with his car key dumped on my desk, that was that. Later that year Sam and Andy were so cool when they flew in at the last minute for our wedding hosted at my in-laws' in the middle of nowhere in beautiful rural Illinois. The day after, for brunch in the house, Sam was there working the crowd recounting how he'd just gone upstairs to the bathroom only to find a disheveled party-goer waking up still in his tux: he acted out what the guy said to him in typical Sam style: "So I was still wearing my suit... and I found a piece of wedding cake in the pocket... AND it was now all warm... AND so I ate it... AND it still tasted GOOD!" Imagine Sam pausing each time, finger in the air, delivering those punchlines! We all loved that.

Ever since the beginning of Gatsby, more than a decade ago, both consciously and subconsciously I have attempted to emulate his traits: notably his style of teaching, which I took to Buffalo and the students soaked up. Students voted mine the best course and when asked they simply said "the course left me drained, I had no time to spend on other work, I would recommend it in a heartbeat". Every time any student thanked me for my time and commitment, I would mention 3 people: Sam, Geoff, and Zoubin. When Sam came to Buffalo to visit, the students were enraptured and understood why I was like I was, and it made me realize how lucky I had been to have him as an influence throughout my grad career, and how lucky I still was that he would drop by to what seemed to me like a remote outpost for machine learning. But like many of us, I will never come close to matching the poised, clear, engaging, funny, and personable Sam.

You know what, Sam: I feel like I still have your keys, and I'm still driving your car around, a lot. And I just want to say thank you.

from Pietro Perona

Sam was one of the most creative researchers in machine learning. He was an exceptional lecturer. He was dedicated body-and-soul to deeper understanding and to teaching other people. He had a warm, generous and engaging personality. During his Caltech years he organized an applied mathematics boot camp for incoming CNS students. If there are angels, Sam is one of them.

from John Hopfield

How do I remember Sam Roweis? I remember the way he joined my group, quietly, self-effacingly. He found that the other student members of the group were people whom he particularly enjoyed interacting with He didn’t push himself forward, but was simply around. One day my secretary, Laura Rodriguez, said to me ‘I think that Sam would like to be part of the group. Isn’t there a desk in the corner of [whatever room it was] that he could have?’ And that was the beginning of my personal interactions with Sam.

I will remember of course his brilliance, accomplishment, and scientific contributions, and catholic interests in science, technology, and what other research students were working on. But I particularly want to note in the Caltech community Sam’s contributions as a teacher. In his era, CNS 185 succeeded or failed on the backs of TA’s. Sam, who had an exceptional gift for explaining things in a clear and interactive fashion, was twice an award-winning TA. He lavished attention and time on individual students, small groups, and on preparing the elaborate problem sets, creating a nurturing environment which made all the difference to the learning and attitudes of scores of Caltech students. In his era, my identification with the success of the 185 was somewhat spurious. The success was Sam.

And I will remember also the many things he taught me, with the same patience and desire to enhance my abilities that he exhibited toward the students. He was an extraordinary scientific colleague, my student and my teacher, a gentle considerate man, and my friend.

from Andy Brown

I first met Sam at the University of Toronto when he was visiting from Caltech. I was just starting out in my PhD while he was already far along on his own. He had come specifically to see Zoubin and flesh out an idea for a paper on linear Gaussian models. They worked tirelessly for the time that he was there. It seemed gruelling to me, but Sam was really excited about the way that Zoubin, in his words, squeezed the knowledge out of him. That first impression of him stayed with me.

I was later happy to learn that he decided to join the Gatsby Unit as a postdoc. He was an inspiration in his enthusiasm for his and everyone's research. Whenever he came across a new idea, other's or his own, he was too happy to share it and always explained it in turns of phrase that made the work both fun and exciting.

We were fortunate to have him at the Gatsby for other reasons too. He was a cornerstone of our tight-knit social circle. Whether it was exploring a new restaurant or a club or our regular brunch gatherings which usually stretched into the late afternoon and beyond, Sam was the key to making it fun. I'll remember many happy times: he and Sham trying (unsuccessfully) to teach me rock climbing, Sunday afternoons dancing at Lazy Dog (he had some fantastic moves), or hitting the east end on millennium New Year's Eve.

One of Sam's great qualities was that he took personal relationships very seriously, and worked hard to make them special. If you did something as simple as invite him over for dinner, you were sure to receive one of his hand-written postcards in the mail (kitschy ones which he collected especially for this purpose), saying what a great time he had and thanking you for the hospitality. And even in recent years when we were less in touch, he never forgot to send along a birthday greeting.

A final thought about Sam's generous and inclusive nature, is of one day talking with Sam and my office mate, Brian, in his office at the Gatsby Unit. We were always aware of how fortunate we were to be working in a place with such brilliant people. By way of encouragement Sam offered the insight that even Geoff Hinton started out as a grad student "just like us". This still makes me smile – I didn't consider myself in the same league as him, but it makes me happy that he thought we had that potential. Nobody was just like him.

Our last meeting was over dinner on a trip that my wife and I took to San Francisco. Sam and Meredith showed Myrocia and me a good time at a great restaurant they recommended. He was typically effusive and entertaining with all his stories, but even happier now that he was sharing his life with someone he loved. That is how I will always remember him. Meredith, we give our love to you, Aya and Orli and we pray that you find the courage to cope in this moment.

from Bruce Francis

I wrote this [in a] letter of reference for Sam in 1995:

"I have known Mr Roweis since January 1993; he attended my third-year course on Signals and Systems.

"Although my contact with him has been via just one course, in fact I believe I know him quite well. The reason for this is that his class participation was so extraordinary: He attended every lecture, answered at least half the questions I asked the class, and offered many suggestions to me afterwards, in written form, concerning the delivery of the course from his perspective. He is certainly the most stimulating undergraduate student I have met in the past, say, ten years.

"The last few lectures of my course were problem-solving sessions. I asked for student volunteers to go up to the blackboard and give solutions to the problems I had posed, while I sat with the other students. In one of these sessions, Mr Roweis volunteered and proceeded to give beautiful solutions with lucid explanations, in fact, a complete polished lecture. Mr Roweis is a born teacher and I'm confident he would become a great professor if he were to pursue this path....

"Mr Roweis has an outgoing personality and he receives enormous respect from his fellow students. It's my impression that he's the leader of the intellectual clique in his class."

from Sebastian Thrun

The loss of Sam continues to be unreal and I am still hoping to wake up from a bad dream. To so many of us, Sam was a role model both as a scientist and as a human being. In our scientific field, he was a rising star. What set him aside from so many others was his ability to engage, be thoughtful, and think out of the box when facing challenging problems. As a person, he was nothing short of amazing for me.

My thoughts are with Sam's family and their countless friends.

from Robert Tibshirani

I first encountered Sam at a Statistical meeting a few years back, when I attended a talk that he was giving. He really bowled me over. I was just amazed by his energy and the clarity of his presentation. I came away thinking: now that's how you give a seminar! He really inspired me to try to improve my own presentations. Last year I visited him at Google and he was generous and brimming full of ideas: a wonderful person to be around. This is a great loss. My heart goes out to his family.

from Serge Belongie

I was fortunate enough to meet Sam during my senior year of college, at which time he was a first year grad student. I remember being scared at the prospect of going to grad school, feeling so overwhelmed at the deep and difficult subject matter I would need to absorb in the coming years. In the midst of this Sam and I became friends and instantly I felt comfortable sharing my fears with him, as well as my excitement about computer vision and machine learning. He was so confident and fearless, filled with the joy of discovery, jumping from one mathematical epiphany to the next. We discovered we both had a penchant for writing up LaTeX notes on cool concepts involving applied math and statistics, though I must admit Sam's notes put mine to shame. Every time he unearthed a nugget of intuition, he was keen to share it with anyone who would listen.

While our academic paths took us to opposite ends of the country, Sam's remarkable intellectual generosity continued to inspire me throughout my grad school years and beyond. With his brilliant intellect and easy charisma, he was equal parts Richard Feynman and Jeff Goldblum. His unexpected death at such a young age is an incomprehensible loss to his family, his friends and his field. One can only imagine the incredible achievements in teaching and research that could have transpired in the decades to come had Sam stayed with us.

from Quaid Morris

Sam was a close friend, a mentor, and an inspiration. I owe many good things in my life to Sam's timely, and often selfless, advice.

I first met Sam on my graduate school interview at Caltech in 1996 though I already knew of him because Geoff Hinton had told me to look him up. Sam had done his undergraduate thesis with Geoff and, as you might expect, greatly impressed him. Though, as we later found out, Sam and I had common friends and experiences from undergrad and high school.

Sam and I both did our undergraduate degrees at the University of Toronto (U of T) though he was two years ahead of me. Sam did his B Eng in Engineering Science, the most difficult undergraduate degree at U of T. In his first year, Sam led his engineering frosh team to victory in their scavenger hunt by single-handedly procuring a transit bus and driving it back to Skule.

Before U of T, Sam attended University of Toronto Schools (UTS), a high school for gifted students. We knew some of the same UTS people and we were at the same Model UN assemblies where Sam's Iraq delegation entertained all us by arranging a visit to the General Assembly by (a fake) Saddam Hussein, managing to get debate stopped repeatedly for calls to prayer (to the consternation of the stiff US delegation from UCC), and in the end, arranging a successful coup of the conference.

On that initial Caltech visit, Sam quickly made me feel welcome and convinced his graduate department to delay my return flight one day so that I could join the CNS departmental retreat and get to know members of the department in a more relaxed setting. I slept on Sam's couch -- he was a dorm fellow (for undergrads) and had an extra room. At that retreat, Sam impressed me by openly criticizing plans to include a "consciousness module" in a upcoming grant proposal. At the time, it seemed brave and foolhardy to confront faculty as a graduate student. Later, I would realize that this was a reflection of Sam's strength of character and desire to do the right thing.

Sam and I reconnected at NIPS in 1998 and at the Gatsby in early 1999, when I was a graduate student and he was a postdoc. Many of us were transplanted from North America, Sam was a social beacon for us in a new, and surprisingly foreign, environment. With his inclusiveness and energy, Sam made the transition easier. In addition to all of the other things Sam was to that first batch of Gatsby students, Sam was a founder, and enthusiastic participant, in chicken escalope Friday's at the Onion when a large group of us would traipse down to "The Onion" sandwich shop in an attempt to optimize the size of our sandwiches. I also remember Sunday afternoons dancing at Lazy Dog in Nottinghill with Sam, a rare treat.

We drifted apart after I followed him to Toronto though I had the pleasure of meeting Meredith and I was happy that she and Sam came to my wedding. I will miss him, terribly.

from Corina Linden

I remember Sam on a long-ago hike, before we were all parents and professors, cavorting down the hillside with a band friends in his wake; posing as king at the crest of the fell; carefree and lolling on the Manor lawn on a golden English afternoon. I remember Sam as funny, sweet, charming and brilliant. I will remember Sam well, with laughter through tears, and hope that that will be enough.

from Tamara Caspary

Towards the end of my time in Princeton when I chose to postdoc in London a friend mentioned that I should meet Sam, who was finishing up his PhD with the new guy from CalTech (unlike the rest of the people who have posted here I had no clue who John Hopfield was and now only know he was lucky enough to have trained Sam), as Sam was headed to London too. It was a totally unremarkable conversation but what a stroke of luck. Sam was born two years and one day after me yet treated me like his younger sister. He introduced me to his friends, threw our 28th and 30th birthday party, always mentioned when he was getting tickets to something, navigated while I drove in central London, explored alleys of London, toured the English countryside, and, along with Maneesh, always made sure a memorable meal was planned along the way. My first night in London Sam met me by the Camden Locks and mapped The Optimized Strategy for me to use the next day on my search for a flat; he optimized it for the buses and trains I would need to take. In retrospect, this was no easy task as I only lasted two months in London without a car but to Sam, using Public Transport efficiently was challenge that just needed to be solved. He was delighted when I chose a flat on the same bus line as he… the C31 connected us that year.

I worked at the outskirts of London on Mill Hill where I could see the buildings of the city from the front of my building and sheep grazing the greenbelt from my bench. We had animal rights protesters every Wednesday night and were not allowed to leave by foot. Sam was fascinated and kept begging to come spend a Wednesday afternoon so he could see it all for himself. I agreed and I remember his giggle as I pulled the car out past the protesters. I always admired his ability to enjoy and seize whatever the moment brought.

In the end I was not as enchanted by my postdoc as I was by London and quit and moved to NYC. But it was because of Sam and Maneesh that it took all year to make that decision. For me that year was the last I felt truly free, my last without my career and marriage and my twins making me always feel so responsible. What a gift you gave me Sam.

from Carlos Brody

I was a graduate student in John Hopfield's group at Caltech when an enthusiastic new student started hanging out in the group. He always carried an enormous blue backpack that seemed to hang down almost to the back of his knees. I never figured out why he needed that huge thing, for the important things that Sam really carried with him were enormous, vibrant enthusiasm, a wickedly charming smile that made you a co-conspirator in his curiosity and his fun, and gifts of clarity and intelligence that were breathtaking in their beauty and joyfulness. He soon joined the group, and how lucky we were! It was a magical time. Sam Roweis' desk was to my left, and Sanjoy Mahajan's to my right. I was older than both of them, but I was soon learning far more from them than anything they would learn from me.

Group meetings were an intellectual feast. The prevailing attitude that John had set was that we were scientists-- not simply neuroscientists, or computer scientists, or mathematicians, or physicists. We were scientists. That meant that any intellectual problem was fair game, and that what we were really looking for were the deeper insights, the ideas that, once understood, would apply broadly, across many fields and problems. Sam took to this like a fish to water.

I remember one of Sam's very first presentations at group meeting, where he vividly described a reduction in needed coding bits as "sending saved bits into a bit bucket." He seemed to have been born with a knack for memorable and clarifying imagery, together with the ability to draw you into the fun of finding revealing ways of thinking. I soon found myself trying to ape Sam's speaking style-- it was so appealing, it was so clear, it was so much fun!! Of course I was never able to do it anywhere near as well as he did. But striving to speak precisely yet informally is one of the many things I learnt from Sam that I will keep with me all my life. Teaching others simply by doing something so appealingly and so well that one wanted to do it like him too was something Sam did all the time.

He was a very generous and kind friend, always willing to hear you if you were down, always ready to join plans that were fun, and invariably adding joyfulness to any proceeding. As others have described here, Sam was the kind of person you just wanted to be around-- you knew life was better with him in the room. He was always ready to exert himself for others, whether he knew them or not.

In recent years I had kept less in touch with him, but I was happy to think that after his move to New York I would get to see more of him again. During these winter holidays, we invited him to come to Princeton to visit us, and he couldn't make it, but we were looking forward to getting together soon. Like many others, I will deeply miss him and the time we could have spent with him.

I am sorry that I did not meet Meredith and the twins before Sam passed away. I hope they can feel that the love we have for Sam extends to them, and that they can take some comfort from reading this blog and its many postings as a testimonial and reminder of the beautiful human being that Sam was.

from Ilana Rubel

I went to high school with Sam for six years at our tiny school in Toronto, where everybody knew everybody else like family. And because my last name is "Rubel," I was always right beside Sam anytime anything alphabetical happened. This was very good fortune for me; Sam was arguably the smartest guy at a school that purported to be packed with geniuses, and his locker being beside mine enabled me to garner his tips for tests and assistance on imminently due homework assignments, undoubtedly saving me from innumerable academic disasters. He always had time to stop, talk and help, despite his outrageously busy schedule. Or talk all night at one of our many class parties about the existence of God, teachers, books, teen social angst, or anything else.

Sam was a phenomenon throughout high school. Not only did he have the top grade in every class, and launch questions and comments that could stump any teacher, but he was the life and soul of the place. Every Wednesday we had a school-wide assembly, which was largely the Sam Roweis show. As co-President of the Science Club (a Sci Guy), he would write and star in skits every week that would be the envy of late night comedians. I remember one time he rigged up some apparatus to come gliding down from the top of the auditorium. He also launched a stealth campaign to put "Science Club" signs up in subway stations, on police cars, and around the city. He also pioneered the perhaps even more entertaining "Shower Club," exhorting his fellow students to bathe after Phys.Ed. He brought such laughter and joy to our school - I'm just so sorry it was in the days before ubiquitous video. I'd so love to have a recording of one of his hilarious skits.

After graduation I didn't keep in touch with Sam, but always knew what he was up to through mutual friends. I do remember at our 10 year reunion that he pointed out what an incredible gift our school had given us, and he started a campaign for everyone in our class that could afford it to give $1,000 to our ever-struggling school. He stepped up as the first donor. We have lost a one-of-a-kind person in Sam.

In a sleepless moment the other day I wrote the following blog about the events of the past week - check it out if you're interested.

I have never met Meredith, but my every thought and best wish is with her, the twins and Sam's other family and friends.

from Y-Lan Boureau

I met Sam for the first time when he was visiting Gatsby in 2005. I remember the first email he sent me at the time was a link to some streaming radio station of progressive trance techno music that he was listening to while coding for his NIPS paper. I had never done any machine learning before, but he is the one who made it sound like so much fun that I ended up getting all excited and landing in Yann's lab at NYU. Perhaps if he had talked about marine biology that's what I would do today.
As so many others have said, Sam was a person you would instantly feel drawn to and want to be close to. His enthusiasm, brilliance and tireless energy had this very unique quality that it would always renew everyone else's. He was not content with shining, he had to shine on everybody with his incredible generosity and uncanny gift for communication that felt like witchcraft.
I was so thrilled when he decided to come to NYU. I couldn't believe how lucky we were, that he was going to be sitting right there every day, in what was then my office.
Last week at the lab meeting, while everybody else was sleepily waiting for latecomers to show up, he was as buoyant as ever and already at the whiteboard, presenting a cute 5-minute trick as an 'incentive for people to show up on time'. He turned every moment into an opportunity to learn and get excited about something.

Sam, for so many of us you were a model, a hero, an inspiration, and an unforgettable presence. You made people optimistic and enthusiastic. Thank you for gracing our lives and being who you were.
I wish we had had more time.