# Computer Scientists: Is this a Donald Knuth joke? **URL:** \ **Category:** Factual Questions\ **Created:** [March 13, 2019, 9:39pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097 "2019-03-13T21:39:45Z")\ **Posts on this page:** 18\ **Page:** 2
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [March 14, 2019, 3:21pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/21 "2019-03-14T15:21:08Z")
Yes, the \*Devil’s DP Dictionary \*has entries for “Loop, endless… _see_ endless loop.” and of course, “Endless loop … _see_ loop, endless”. the other explanation obviously (but less funny) is that it was generated by an automatic indexing system during typesetting. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [March 14, 2019, 3:35pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/22 "2019-03-14T15:35:11Z")
> [@md2000](#): > > Yes, the \*Devil’s DP Dictionary \*has entries for “Loop, endless… _see_ endless loop.” and of course, “Endless loop … _see_ loop, endless”. > the other explanation obviously (but less funny) is that it was generated by an automatic indexing system during typesetting. I can’t imagine Knuth resorting to any automatic indexing system. ETA I mean, obviously the printed index is automatically generated by (Knuth’s) typesetting system, but the terms to index he put into the book’s source file by hand. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [March 14, 2019, 3:39pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/23 "2019-03-14T15:39:49Z")
Not directly related to this, but still an index inside joke. George B. Thomas, author of the best-selling _Introduction to Calculus and Analytic Geometry_ (a version of which was used by my high school, as well as at MIT, where Thomas taught) told our class this one himself. If you go to the index in certain editions you find an entry for “whales”. If you then go to the page you won’t find a reference to whales. What you _will_ find is a graph with one of those Richard Powers-esque mathematical blobs on the plot. Thomas and his editor, who were apparently going through the galleys by hand were getting pretty punchy by this point. One of them said that the shapes looked like whales, and the other suggested they put it in the index. So there’s a reference to “whales” in the index of a calculus book because a tired and sleep-deprived author and editor thought it was funny that a pair of mathematical curves looked like a whale. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 14, 2019, 3:46pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/24 "2019-03-14T15:46:32Z")
Shouldn’t the MMIX version have already come out a decade ago? ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [March 14, 2019, 3:55pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/25 "2019-03-14T15:55:15Z")
> [@Chronos](#): > > Shouldn’t the MMIX version have already come out a decade ago? MMIX itself did (or has it been two decades?), but revising Volumes 1-3 had to wait until Knuth finished volumes 4 and 5. Meanwhile all the programs are available in MMIX on the pages of the MMIX Users’ Group. Re. index fun: I saw some technical book (in English) deliberately index an egregiously humungous German compound word, which is quite noticeable when you flip the pages. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 14, 2019, 4:07pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/26 "2019-03-14T16:07:58Z")
No, two decades ago was the MIM version. ---
**Author:** ![echoreply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/echoreply/32/3641_2.png) [@echoreply](https://boards.straightdope.com/u/echoreply)\ **Post date:** [March 14, 2019, 5:22pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/27 "2019-03-14T17:22:47Z")
Knuth also published in Mad Magazine. ---
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [March 14, 2019, 6:32pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/28 "2019-03-14T18:32:48Z")
It doesn’t do much to explain the joke in the OP, but just yesterday I was just reading about another self-referential book index entry. Mathematician Paul Halmos promised his colleague G.P. Hochschild that he would put him in his book _Finite Dimensional Vector Spaces_. The index entry on page 198, naturally, reads “Hochschild, G. P., 198.” More information [here](http://mathforum.org/kb/thread.jspa?forumID=149&threadID=383167&messageID=1181198). ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [March 14, 2019, 7:47pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/29 "2019-03-14T19:47:15Z")
> [@DPRK](#): > > I can’t imagine Knuth resorting to any automatic indexing system. > > ETA I mean, obviously the printed index is automatically generated by (Knuth’s) typesetting system, but the terms to index he put into the book’s source file by hand. Not entirely accurate. You can put the index entries into your tex file and it will be written to a special .idx file, but it requires a third party program called makeindex to actually turn it into an index file that tex can read. Speaking of user groups, the tex user group TUG is alive and well and is enormously successful in promoting tex around the world. ---
**Author:** ![74westy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/74westy/32/3950_2.png) [@74westy](https://boards.straightdope.com/u/74westy)\ **Post date:** [March 14, 2019, 8:58pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/30 "2019-03-14T20:58:46Z")
> [@Donald Knuth](#): > > Beware of bugs in the above code; I have only proved it correct, not tried it. The guy was a laugh a minute. Godel, Escher, Bach had recursive index entries I’m pretty sure because, duh, Hofstadter. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [March 15, 2019, 2:41am UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/31 "2019-03-15T02:41:29Z")
> [@Hari\_Seldon](#): > > Not entirely accurate. You can put the index entries into your tex file and it will be written to a special .idx file, but it requires a third party program called makeindex to actually turn it into an index file that tex can read. I meant that the words to index are marked in the tex file by the author, instead of a computer program automatically generating a list of keywords or a concordance. You can tell Knuth does it this way because of his little jokes and the overall high quality of the index. For the actual compilation, xindy may be more flexible than makeindex. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [March 15, 2019, 4:00am UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/32 "2019-03-15T04:00:32Z")
Speaking of Knuth’s typesetting, in the TeXbook there is a chapter explaining how to work with macros. The page headers say “Definitions (also called Macros)”, except on one page where it reads, “Definitions (aka Macros)”. Could somebody explain the joke? ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [March 15, 2019, 1:15pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/33 "2019-03-15T13:15:31Z")
> [@echoreply](#): > > Knuth also published in Mad Magazine. Another example of Knuth’s whimsy is his article on [the complexity of songs](https://en.wikipedia.org/wiki/The_Complexity_of_Songs). ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [March 15, 2019, 1:58pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/34 "2019-03-15T13:58:34Z")
> [@ticker](#): > > A recursive reference to recursion would be funnier. In 1981 I was working at a company using PR1ME computers. One of the manuals had these index entries: recursion: See _circular reference_ circular reference: See _recursion_ Recursion and circular references are not exactly the same thing but I did get a chuckle out of it. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [March 15, 2019, 3:18pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/35 "2019-03-15T15:18:20Z")
> [@Musicat](#): > > My WAG is it _used_ to be funnier. Not all humor ages well. As someone who regularly watches Johnny Carson on AntennaTV, I agree heartily. ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [March 16, 2019, 12:10am UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/36 "2019-03-16T00:10:13Z")
> [@74westy](#): > > Godel, Escher, Bach had recursive index entries I’m pretty sure because, duh, Hofstadter. [Yes](https://en.wikipedia.org/wiki/G%C3%B6del,_Escher,_Bach#Themes), and I came here to say that. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 16, 2019, 4:17pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/37 "2019-03-16T16:17:14Z")
I also said that, [here](https://boards.straightdope.com/sdmb/showpost.php?p=21541050&postcount=37). ---
**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\ **Post date:** [March 16, 2019, 9:43pm UTC](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097/38 "2019-03-16T21:43:30Z")
> [@Chronos](#): > > I also said that, [here](https://boards.straightdope.com/sdmb/showpost.php?p=21541050&postcount=37). 😃 [Previous page](https://boards.straightdope.com/t/computer-scientists-is-this-a-donald-knuth-joke/831097.md?page=1)