D is for Donald Knuth

Donald Knuth describes himself as a professor of computer science, but he's known for many other things.  His biggest claim to fame is probably for creating the typesetting system TeX, which has been the lingua franca of academic writing in math and science for many decades.  He's made valuable contributions to both abstract mathematics and to Mad Magazine, and he's written books on philosophy and religion.

Knuth spent many years teaching, but he retired early with the intention to spend the next 20 years finishing his magnum opus, The Art of Computer Programming, a comprehensive multi-volume textbook of algorithms and their analysis.  I've only browsed through the early volumes (without digesting much), but I'm told they're utterly foundational to really knowing how to do programming right.

It's said that Knuth developed the TeX program, which allows one to do professional-level typesetting with equations and math symbols, just in order to be able to make his computer programming books as aesthetically pleasing as possible.  He also designed programs to create his own fonts to assist in this aim as well... his Computer Modern typeface is still used by thousands, including yours truly, on a daily basis.

Knuth has seemingly lived by William Blake's motto "I must Create a System, or be enslav'd by another Man's."  :-)

I've also been fascinated by Knuth's contributions to John Conway's idea of surreal numbers.  It's an alternate take on set theory and the mathematics of infinities that many describe as awe-inspiringly insightful.  When Conway introduced the basic idea to Knuth in the early 1970s, the latter went off and wrote a short novelette that presented the ideas in the form of a dialogue between two beach bums (Alice and Bill) who discovered the axioms of surreal number theory carved on a rock.  Of course, they go on to prove all manner of interesting theorems.  At the end, Alice rapturously falls into Bill's arms and says "Every discovery leads to more, and more!"  Bill glances at the sunset and says that "There are infinitely many things yet to do... and only a finite amount of time..."

Okay, Shakespeare he's not, but Knuth is really quite unique.  Let me just end with a couple of quotes from his philosophical book Things a Computer Scientist Rarely Talks About,

"Somehow the whole idea of art and aesthetics and beauty underlies all the scientific work I do. Whatever I do, I try to do it in a way that has some elegance; I try to create something that I think is beautiful. Instead of just getting a job done, I prefer to do my work in a way that pleases me in as many senses as possible."

and

"In any case, I think people who write programs do have at least a glimmer of extra insight into the nature of God... because creating a program often means that you have to create a small universe. [...]  I think it's fair to say that many of today's large computer programs rank among the most complex intellectual achievements of all time. They're absolutely trivial by comparison with any of the works of God, but they're still somehow closer to those works than anything else we know."

Long may Don Knuth program!