Juggling Patterns and Programs

The art of juggling has fascinated people since the days of ancient Egypt. In this talk, we posit that juggling theory can inform software development. We start with the mathematical insights of Claude Shannon, renowned as the father of Information Theory. After introducing “siteswap” notation, we use Clojure to visualize juggling patterns. Finally, we review some interesing results in neuroscience regarding juggling.

Presented at Clojure/conj 2016.
video: https://www.youtube.com/watch?v=TqG176T69VM

Transcript

1. Juggling Patterns and Programs
   Steve Miner
   @miner
   

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3. Anthony Gatto
   Cirque du Soleil
   

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4. Simple Made Easy
   Rich Hickey
   Strange Loop 2011
   

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5. Metaphor Alert
   RH ~ incidental complexity
   Me ~ essential complexity
   https://schani.wordpress.com/tag/juggling/
   

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6. Scientific Aspects of Juggling
   Claude Shannon (1916 - 2001)
   written in1980s
   

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7. Egyptian Wall Painting
   circa 2040 B.C.
   

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9. Uniform Juggle
   • one throw at a time
   • alternating hands
   • constant rhythm
   

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10. 3 Ball Cascade
    • Odd numbers: cascade
    • Even numbers: fountain
    

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11. 4 Ball Fountain
    • Odd numbers: cascade
    • Even numbers: fountain
    

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12. Shannon’s Juggling Theorem
    • Flight time
    • Dwell time
    • Vacant time
    • number of Balls
    • number of Hands
    

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13. Complex Made Hard
    • B ≈ F
    • F ≈ (sqrt height)
    • small errors compound
    

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14. Flying Karamazov Brothers
    scaling H
    

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15. Shannon’s Juggling Theorem
    • Flight time
    • Dwell time
    • Vacant time
    • number of Balls
    • number of Hands
    

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16. Lessons from Shannon
    • historical analysis
    • domain understanding
    • choosing right abstraction
    • exploring trade-offs
    

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17. Science of Juggling
    • Peter J. Beek and Arthur Lewbel
    • Scientific American, November, 1995, Volume 273,
    Number 5, pages 92-97
    • www.juggling.org/papers/science-1/
    

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18. Siteswap Notation
    • sequence of integers
    • e.g. 531 = [5, 3, 1] …, 5, 3, 1, 5, 3, 1, …
    • 3 = standard three-ball cascade
    • odd for cascade, even for fountain
    • empty 0, switch1, hold 2
    

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20. Inventors
    • Paul Klimek - UC Santa Cruz 1981
    • Bruce Tiemann and Bengt Magnusson - Caltech
    1985
    • Michael Day, Colin Wright and Adam Chalcraft -
    Cambridge 1985
    

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21. Number of Balls
    • average of throws, must be an integer
    • 531 (/ (+ 5 3 1) 3) 㱺 3
    • 71 (/ (+ 7 1) 2) 㱺 4
    • 97531 (/ (+ 9 7 5 3 1) 5) 㱺 5
    

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22. Validate Pattern
    (defn siteswap? [pattern]
    (let [cnt (count pattern)]
    (or (zero? cnt)
    (apply distinct?
    (map #(mod % cnt)
    (map-indexed + pattern))))))
    

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23. Spec
    (s/def ::siteswap
    (s/and (s/coll-of (s/int-in 0 10) :kind vector?)
    siteswap?))
    

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24. Orbits
    • Decompose pattern into orbits (sub-patterns)
    • 531 = 501 & 030
    • 4413 = 4000 & 0400 & 0013
    • 97531 = 90001 & 07030 & 00500
    • Practice separately
    

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25. Quil
    • Clojure library for graphics and animations
    • quil.info
    • Rastelli - Clojure juggling library
    

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26. 453
    3 balls in 450
    1 ball in 003
    

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27. 97531
    2 balls in 90001
    2 balls in 07030
    1 ball in 00500
    

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28. Isomorphic Patterns
    • repeat: 3 㱺 333
    • rotate: 531 㱺 315 㱺 135
    

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29. New Patterns
    • add period to element: 33 㱺 53
    • swap sites i & j
    • add distance earlier, subtract distance later
    • guarantees same landing schedule
    • 333 㱺 531 531 㱺 441
    

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31. State Diagram
    https://plus.maths.org/content/juggling-maths-and-beautiful-mind
    

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32. Siteswap Features
    • simple data representation
    • flexible interpretation
    • sharing
    • composition
    • verification
    • generation
    

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33. Additional Resources
    • juggling.org
    • thewjf.com
    • wikipedia.com
    • siteswap.net/JsJuggle.html
    • jugglinglab.sourceforge.net
    

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34. The Mathematics of Juggling
    • Book by Burkard Polster, Monash University
    • Survey article based on his book
    • www.qedcat.com/articles/juggling_survey.pdf
    • YouTube videos on juggling
    

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35. – Burkard Polster
    The way that I feel when I look at a
    nice equation is the same way I feel
    when I look at a nice juggling pattern.
    

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36. Allen Knutson
    • Math professor at Cornell
    • Siteswap FAQ on rec.juggling
    • YouTube video on
    mathematics of juggling
    

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37. Neuroscience
    • Plasticity In The Adult Brain: Why We Care About
    Taxi Drivers & Jugglers
    • Marc W. Haut, PhD
    • youtube.com/watch?v=JVsZVW2HRYQ
    • nature.com/nature/journal/v427/n6972/full/
    427311a.html
    

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40. Jennifer Slaw: Juggling Life
    • TEDxPrincetonlibrary talk
    • motivational speaker, teaches
    juggling
    • improves memory,
    concentration, flexibility,
    patience, balance
    • youtube.com/watch?v=S-
    Rohq5649A
    

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41. – Michael Moschen
    What you learn is how to feel with your eyes
    and see with your hands.
    

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42. Recap
    • Juggling inspires mathematicians
    • Siteswap notation is a juggling DSL
    • Rastelli juggles with Clojure
    

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43. ClassicProgrammerPaintings.com
    

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44. photo by Lisa J. Miner
    

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46. The End
    

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