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Figuring out how to typeset and the problem with specifications


Working on my letters and problems with the S
Donald Knuth Scientist
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In June of 1977 my sabbatical begins, classes are over, I'm ready to… to go on this and I… and I had sketched out ways to do lower case alphabet, a to z, and… and with mathematical specifications.  And I thought great, this will… this will solve my problem because I… I… you know, I can make the letters all different sizes with slight changes in the specifications. A… a good type design doesn't just make nine-point letters, nine-tenths of a tenth…  size of a ten-point letter, but they also make them a little bit wider, subtle changes in the… in the… the greyness of the characters and… but I could design my program with these parameters to do the variations and draw each letter to… at each size properly. This is a very natural thing for a computer scientist to… to do because we're… we’re used to specifying things with parameters all the time. I mean we… we have a job to perform and… and we… we have certain things variable, and… and we twiddle those dials and that will give us a different output. What… but I found out to my surprise that when I was talking later to… to people in the graphics industry, I… they hadn't heard the word parameter before, and… and they thought it meant perimeter and… and I mean, it was… it was something that, you know… but computer people think it's just as natural as…as anything.

Well, so I came up with 25 of the 26 letters in the middle of June and they weren't beautiful but they were pretty close to… to being okay to my eyes at the time, but then there was the letter S.  And I couldn't figure out how to draw a blasted S. And, I… it… it has a very peculiar shape where it… it changes over from curves, sort of, curves left, then right a little bit, and then back and forth, and what's going on in this… in this shape. None of my mathematical formulas would… would handle it.  And I spent several days without sleep up at the… up at the lab, you know, trying different things and every time it would just look very ugly. And after… finally, I had to… I had to come home and, you know, and… and go to bed and… and I showed my results to Jill and she said to me, ‘Well Don, why don't you make it s-shaped?’ That was her solution to my problems. Well, oh man, what was I going to do? So, but… but finally after, I don't remember how many days it was, counting the nights, anyways… well anyways it seemed like an eternity… eternity, I… I got the idea that… that I could go back to a… a geometry problem that the Greeks might have enjoyed about ellipses, where if you… if you have an ellipse in it, and you try to make it… the ellipse just big enough so that… that the… the tangent, as it's coming down, meets things in a… in a proper way, it… we… it become a problem that would be interesting to… to Euclid or somebody, although I don't think it was… it appeared in his work. And that would be a way to… to actually figure out… the ellipse would be for part of the S… and when… and then when it comes to this tangent, then we go off on that tangent and go to the other part of the S, and… so I had finally a mathematical formula that I could, that… that looked like an S, and I could change some of the parameters and it would look like a slightly different S, and so on.
But before I came up with that formula, I was thinking, well, maybe I could change my book, you know, and try to avoid using the letter S entirely… and then I… but then I, you know, I'd have to leave Stanford. So it was… I… I would go, you know, visit Safeway and they had a funny looking S, you know, and I would see all the different S's everywhere.  Though to finally solve the problem of the S, right.  But… but incidentally, I… I never did solve the problem of the… of the dollar sign, though… the dollar sign that I have is still pretty ugly and… and I'm waiting for some… some new idea to come along, but I never was too much interested in dollars really, so I… I didn't bother to spend too many days on that.

Born in 1938, American computing pioneer Donald Knuth is known for his greatly influential multi-volume work, 'The Art of Computer Programming', his novel 'Surreal Numbers', his invention of TeX and METAFONT electronic publishing tools and his quirky sense of humor.

Listeners: Dikran Karagueuzian

Trained as a journalist, Dikran Karagueuzian is the director of CSLI Publications, publisher of seven books by Donald Knuth. He has known Knuth since the late seventies when Knuth was developing TeX and Metafont, the typesetting and type designing computer programs, respectively.

Tags: Greek, Stanford University, Safeway, Euclid, Jill Knuth

Duration: 4 minutes, 42 seconds

Date story recorded: April 2006

Date story went live: 24 January 2008