Page 35                                                 Winter 1993-94

 

The diagram also appeared in Peter Jan Beek's 1989 Ph.D. thesis from Vrije Universiteit in Amsterdam, "Juggling Dynamics." Beek calls the diagram a "tonality ladder," and says he heard about it from Charlie Dancey, a former partner of the noted U.K. juggler Haggis. The diagram also shows up in Kaskade number 25, March 1992, in ''Juggling on Paper" by Joachim Voigt, pp. 16-17 (note this is the same title as Simpson's article). Voigts version has an extension for marking the type of throw in club juggling (e.g., number of spins). The diagram reappears in Kaskade #29, in "Workshop - Juggling Theory, part 1: The DAB Theorum (sic) and other serious illnesses" March, 1993, pp. 35-37, by JOTA (Jongliertheoretische Arbeitgemeinschaft). It is also mentioned (though not used) in Martin Probert's 1990 book, "491 Patterns for the Solo Juggler."

 

Another variant of the diagram, designed to show the length of time that hands spend full and empty, is in "Juggling Made Complicated" by Jack Kalvan. Jack's unpublished paper has many interesting results in it, including a calculation of the maximum permitted errors to avoid collisions in standard juggling patterns. Jack also worked on the now-defunct juggling robot project at IBM, and is half of the noted juggling duo Clockwork. (Although Jack and Rick Rubenstein didn't know it when they named themselves Clockwork, the name is reminiscent of how the Elgins, a Vaudeville juggling group, were named. Elgin was the name of a watch manufacturer at the time. The group walked by a jewelry store that posted the ad, "Elgin: precision timing" and decided that was a good name for a juggling troupe).

 

So, did Simpson 1986 invent the diagram? No. Both Voigt and Probert refer back to Jeff Walker. This is the 1982 article I skipped over above. It is "Variations for

Numbers Jugglers," in the January 1982 issue of Juggler's World, page 11. This short article, less than one page, not only has the juggling diagram, but uses it to invent some site swap moves, contains the basic site swap idea of having, for example, a 5 denote a five ball cascade throw, and even has synchronous throw and multiplex tricks!

 

So Walker laid the groundwork for site swaps and MHN, but did he also invent the diagram? Perhaps, but around 1981 Claude Shannon began writing an article called, "Scientific Aspects of Juggling." It was supposed to appear in Scientific American, but he never finished it. After gathering dust for over a decade, it was finally published a few months ago in the book: "Claude Elwood Shannon Collected Papers," edited by N.J.A. Sloane and A. D. Wyner, New York: IEEE press, pp. 850­864. The paper has no site swaps, but there in Figure 5 are three juggling patterns, depicted using the same diagram.

 

Interestingly, in every place the diagram appears except in Shannon's and Kalvan's articles, the diagram is drawn vertically with the time axis running from top to bottom. Only Claude and Jack followed the standard convention in physics and math of having the time axis run from left to right, (thanks to Peter Beek for noticing this).

 

Apparently, something clicked in the 1980's, causing the site swap diagram and notation to be independently rediscovered many times. In contrast, the 1990's are fast becoming the decade where the theory goes into practice, with jugglers everywhere learning how to perform site swaps. Remember when a 3-3-10 was a club passing pattern and not an illegal site swap for 5-1/3 balls?

 

"The Academic Juggler" is an occasional feature of Jugglers World, and is devoted to all kinds of formal analyses of juggling. Anybody who has suggestions, comments, or potential contributions for this feature is encouraged to write to me, Arthur Lewbel, Lexington, MA. Please include a phone number if you write. 

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