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Pat Hanrahan: “Curiosity and passion determine success”

The Turing Award-winning computer scientist discusses his path to Stanford and how his approach to working with students is informed by his work with the cofounder of Pixar.

Pat Hanrahan: “Curiosity and passion determine success”

April 15, 2021
Computer Science Professor Pat Hanrahan

Pat Hanrahan: “I absolutely love teaching.” | Photo by Andrew Brodhead

When Pat Hanrahan was in elementary school, he was already checked out.

Even though he was an inquisitive kid, he was not engaged and not doing well. And then his uncle, a high school student, moved into Hanrahan’s room. One day, he observed his uncle working on an experiment on the planaria flatworm at his desk. Curious, Hanrahan scooted closer and asked him what he was doing. His uncle answered Hanrahan’s questions in a way that he remembers as quite gentle, and from then on, his uncle would teach him everything that he was learning. His uncle’s work was challenging, and his gentle manner encouraged Hanrahan to ask more questions. That relationship cultivated in him a practice of learning outside the classroom and letting his curiosity guide him toward people and experiences that excited and challenged him. Now, as the Canon Professor in the School of Engineering, with appointments in the departments of Computer Science and Electrical Engineering, Hanrahan passes that on, encouraging his students to be curious and take charge of their own learning.


I grew up in Green Bay, Wisconsin. I was an oddball, loving math and science in a town that was obsessed with football. When I was a boy, my father taught me to play chess, and it became an outlet for me. I threw myself into the game and, in the process, cultivated a discipline of study and focus that has served me throughout the rest of my life. I went so far as to teach myself Russian so I could read the obscure Russian chess magazines and memorize tactics. I did well at the tournaments and came close to achieving a master’s rank, but my success in chess was not reflected at school. I was not doing well, and by senior year, I didn’t have any real plan for after graduation. I had worked at the paper mill the summer before, so that was an option, and then on a whim, I applied to the University of Wisconsin. If you had a C average and you were a state resident, they basically had to take you, but I was still so surprised when I got in. They required a placement exam for math and science, and I didn’t know much physics, so I remember the night before the test, I crammed as much physics into my head as possible. The concentration skills from chess must have kicked in, because I ended up getting the highest score in the state, and the physics department invited me to be one of three students in the honors program. I accepted and went off to college.

Discovering graphics

My physics adviser found me a job that allowed me to pay for my education — my family would not have been able to cover the costs — and then he told me that as part of the honors program, I could take whatever I wanted. So I did. Psychology, biology, chemistry, physics, math — I was amazed by all the ideas and all the interesting people around me. I flourished in the academic environment. By the time graduation rolled around, I wanted to stay so I matriculated into a biophysics doctoral program with A.O.W. Stretton, Tony Stretton. It was a hardcore experimental biology lab studying the motor nervous system of the nematode Ascaris lumbricoides, a relative of Caenorhabditis elegans. Each week, I would go to the nearby Jones Farm slaughterhouse to collect worms from pigs’ stomachs and then stick them with electrodes. Early on, I developed a theory of how the motor nervous system generated the wave motion that propelled the worms, and I wanted to prove it by writing a program to simulate the movement.

As I was learning to code, I had a roommate that was into programming, and he introduced me to this new thing called computer graphics. It seemed like a fantasy. All of a sudden, I could turn numbers into a 3D image of a worm undulating on the screen. I was enamored. I somewhat abandoned my worm research and devoured everything I could find about graphics. I also reserved as much time as I could on the powerful computers around campus so I could play around with what I was learning. But it wasn’t enough. I wanted to be around the people working in this field, asking them questions and contributing my own ideas. So, I reached out and got an offer to work for the Computer Graphics Lab at the New York Institute of Technology (NYIT). I knew that was where I wanted to be, so I left my PhD program behind and went for it.

Founding the field

At NYIT, I was living and breathing computer graphics. It was a haven for everyone in the world who was interested in this new thing. After a couple years, though, the real action had shifted to the West Coast along with the core group of people who would found Pixar. I wanted to be there, in the middle of it all, so I managed to get a job through my connections. There was a brief window of time between leaving NYIT and starting at Pixar, and it felt like a good time to go back and finish my PhD. My advisors had been encouraging me, and even though my dissertation wasn’t groundbreaking, I was glad to graduate. When I made it to Pixar, I again felt like I was in heaven, surrounded by people who were just as enthusiastic as me about sharing ideas and experimenting all day long.

It was hard, though, because the company wasn’t yet financially successful. Every day, there was a possibility that the company, and this nirvana, could dissolve. I proposed an idea that I thought could make a little cash for the company. It became the RenderMan software, which ended up being used to make many computer-generated movies, but at the time, my idea was completely born from the practical need to survive. I learned a ton about managing people while creating this product, but the revenue was not enough to keep Pixar out of hot water, and I began to feel the pull of academia.

Teaching the next generation of visionaries

As a graduate student, I had actually wanted to become a professor, and so I tried applying to academic jobs. It turned out that universities were eager to have someone with my experience, and after a brief stint at Princeton, I came to Stanford. Back in academia, I found that I was more suited to teaching, mentoring and collaborating with students on exciting ideas than to straight software engineering. I absolutely love teaching. I teach the basics of computer systems programming to freshmen and sophomores, and I enjoy when I have students who don’t know much about it. I was so amazed when I discovered programming and graphics for the first time — being able to offer that eye-opening experience to others is very rewarding, especially when I see my students’ curiosity sparked.

More than talent or hard work, I have observed that curiosity and passion determine success, and I really advocate for my students to listen to those inner motivations. With my graduate students, I give them total freedom to do all the fun stuff while I am there, as present as possible, to guide them in their explorations, an approach I actually learned from my Pixar supervisor, Ed Catmull. Now, after almost three decades at Stanford, I am thinking about retiring and working more on my own projects, but I am not ready yet to leave teaching. I encounter such amazing students, and their energy and excitement continue to inspire me.