Carl de Boor is extremely humble about his accomplishments over the course of his long career in mathematics. “My contribution is relatively small; I was at the right place at the right time. I saw what needed to be done. Any competent person would have done the same thing.”
All said by the winner of the National Medal in Science in Mathematics and Computer Science (among many other honors) for contributions that are part of algorithms that pretty much run our world. The graphics we see, the curve of lines in the text you are reading, all of that uses splines, B-splines in particular, to describe curves. Computers couldn’t operate without them, and some of the early formulas that Carl developed have become so standard that they aren’t associated with him anymore.
He adds, “I did organize a certain piece of mathematics and came up with the right ideas, in the area of splines, something I came across when working at GM. It was at that point a very new thing. I supplied some algorithms to work with splines and they have become universal.”
Emigrating from Germany to be with his new bride, Carl had a high school degree when he started graduate classes at Harvard. He transitioned quickly to an early computing position at the General Motors Research Center and made a name for himself working there. At GM, he learned much from Garrett Birkhoff, a consultant, and from John R. Rice, a colleague there. Eventually he attended a two-week summer workshop at the UM where leaders in numerical analysis talked about the state of the art, and he was intrigued by the work they presented. That experience helped him take a closer look at his own situation, and he realized “that the primary difference between him and the Ph.D.s he worked with was that they got paid twice as much and got more freedom.”
Graduate school in Ann Arbor was the natural choice at that point. Carl states, “I was an unusual grad student because I had already had papers published. I was independent and had a clear view of what I wanted to do.” The first year, he continued to work half time at GM and commuted to Ann Arbor as a full time student. As you may expect, he recalls, “It was awful. I got sick at the end of my first semester and ended up in the hospital during finals. After that year, Rackham gave me a fellowship that allowed me to suspend my GM job and move to Ann Arbor with my wife and children. That fellowship made all the difference.”
A recurring regret was that he buckled down and finished his degree in the minimum three years required at the time. He explains, “Because I was married with kids, I needed to go back to work and make money. Now I feel I shortchanged myself and should have stayed another year. There were moments along in my career when I wish I’d know this or that. Graduate school was a very intense three years, but it was a very different experience than my time at Harvard. There, it was much more competitive – people wouldn’t even talk to you. At U-M, it was totally different, very much a cooperative venture. I liked that much better.”
Carl finished in 1966, a lifetime ago for many. “Those were the days when you didn’t have to apply for jobs, they applied to you. I got offers from universities all around and settled on a job at Purdue because I would be able to work with my former GM colleague, John R Rice, with whom I had already published. Also, after complaining about the required text for an undergraduate course in Numerical Analysis, its author, the chair of the department., Invited me to help with two new editions. In those days, in many ways, that was a very lucky part of my life,” he admits.
Iso Schoenberg, the ‘father of splines’, was a long time member of the Mathematics Research Center at the University of Wisconsin and lured Carl there with a full professorship. “The position didn’t require me to teach, just do research. This gave me time at a focal point for applied mathematics, and make great contacts,” he says. He worked with first-rate postdocs during his tenure at U-W and wrote a basic textbook on splines, in addition to countless other publications. Carl retired from U-W after 31 years as a faculty member.
When asked what advice he can offer current graduate students, Carl laughs and says, “Get a Rackham fellowship. It certainly helped me greatly. But really, I think the best advice I can give is to speak up in lectures. Actively participate. Ask questions. Be aggressive in that regard.”
He remembers, “My last two years, I didn’t take notes in classes. I listened intently and then went home and worked it all out. I could participate more fully. Class time is the one time when you have the chance to think along and ask questions.”
Now retired and living on an island off the coast of Washington, Carl has time to reflect on his long career. When asked what stands out as most meaningful in his forty plus years as a faculty member, he answers, “It is doing mathematics. Mathematics for me is very difficult because most of the time, I don’t understand it. I feel like an idiot, but I persist. One has to have a very strong ego in order to withstand weeks and months of feeling stupid. But every once in a while, I finally really understand, and when that happens there is nothing in the world like it. You’re on top of the world. I’ve been in that position only a few times; it was quite wonderful.”
Carl is still writing books, but he says, “Being retired, there is less urgency to get it done. I’m living at a beautiful space – paradise – and I enjoy the view out of my window. The urgency to work is not there. I get a lot less done, but that’s ok too.” Modest again, Carl finally mentions that he still serves on editorial boards in his field and is the treasurer for a fantastic chamber music festival on Orcas Island. “I’m learning so much about music and getting to know musicians. It is a part of my daily life, because the organization is dependent on donations, and the day to day operations involve being careful with our funds. As treasurer, I’m careful of money.”
That care extends to U-M as well. Carl has graciously made a bequest in his will to support graduate education at U-M. He explains, “I felt it’s important to acknowledge the help I’ve gotten. I’ve been helped greatly by certain outfits, and U-M, specifically the graduate school, was very helpful to me.”