Transcript Juggling Sequences with Number Theory
Juggling Sequences with Number Theory
& “A Tale of Two Kingdoms”
Juggling Sequences with Number Theory
Stephen Harnish Professor of Mathematics Bluffton University
Miami University 35 th Annual Mathematics & Statistics Conference: Number Theory September 28-29, 2007
Classical Results
Theorem 1: (Euler) The sequence (3k)(k+1) +1
k
0 has no equal initial and middle sums.
Theorem 2: 3
k k
(Dirichlet) The sequence
k
k
0 has no equal initial and middle sums.
Initial and Middle Sums of Sequences
• Note that sequence {1, 2, 3, 4, …} has numerous initial sums that equal middle sums: (1 + 2) = 3 = (3) (1 + 2 + 3 + 4 + 5) = 15 = (7 + 8) (1 + 2 + 3 + 4 + 5 + 6) = 21 = (10 + 11) (1 + 2 + 3 + 4 + 5 + 6) = 21 = (6 + 7 + 8)
Sequence Sums
Definition: For the sequence
x x x
1 , 2 , 3 , an
initial sum
is any value of the form
I k
1
x
2 for some integer
k x
3 1,
x k
and a
middle sum M
x j
is any value of the form
x j
1
x j
2
x k
for some integers
j
and
k
, where
k
the
length
,
x k
, 1;
Initial and Middle Sums of Sequences
• Note that sequence {1, 2, 3, 4, …} has numerous initial sums that equal middle sums: (1 + 2) = 3 = (3) (1 + 2 + 3 + 4 + 5) = 15 = (7 + 8) (1 + 2 + 3 + 4 + 5 + 6) = 21 = (10 + 11) (1 + 2 + 3 + 4 + 5 + 6) = 21 = (6 + 7 + 8)
Results
Theorem 3:
x
1 1,
x
2 Every initial sum of the sequence 2,
x
3 3,
x
4 4, ,
x k
k
, is equal to some middle sum Conjecture 1:
x
1 1,
x
2 Given the sequence 2,
x
3 3,
x
4 4, ,
x k
k
, equal to some k-length middle sum.
Initial and Middle Sums of Sequences--Fibonacci
• Note that sequence {1, 1, 2, 3, 5, 8, 13…} has the following initial sums: (1) = 1 = (1) (1 + 1) = 2 = (2) (1 + 1 + 2) = 4 (1 + 1 + 2 + 3) = 7 (1 + 1 + 2 + 3 + 5) = 12 (1 + 1 + 2 + 3 + 5 + 8) = 20
Results
Conjecture 2:
x
1 2,
x
2 Some initial sum of the sequence 4,
x
3 6,
x
4 8, ,
x k
is equal to a k-length middle sum for each k.
Theorem 4:
x
0 1, The Fibonacci sequence
x
1 1,
x
2 2,
x
3 3,
x
4 5, has only two instances of equal initial and middle sums. Namely, middle sums (1) and (2).
(Hint: use the fact that
x
0 1
x
2
x k x k
2 1 and compare with the magnitude of each middle sum of length 1, 2, 3, etc.)
Juggling
•
History
1994 to 1781 (BCE) —first depiction on the 15 unknown prince from Middle Kingdom Egypt.
th Beni Hassan tomb of an • • •
The Science of Juggling
1903 —psychology and learning rates 1940’s—computers predict trajectories 1970’s—Claude Shannon’s juggling machines at MIT •
The Math of Juggling
1985 —Increased mathematical analysis via site-swap notation (independently developed by Klimek, Tiemann, and Day) •
For Further Reference:
• Buhler, Eisenbud, Graham & Wright’s “Juggling Drops and Descents” in
The Am. Math. Monthly
, June-July 1994.
• Beek and Lewbel’s “The Science of Juggling”
Scientific American,
Nov. 95.
• Burkard Polster’s
The Mathematics of Juggling,
Springer, 2003.
Juggling Lab
at http://jugglinglab.sourceforge.net/
Juggling Patterns (via
Juggling Lab
)
Thirteen-ball Cascade
A 30-ball pattern of period-15 named: “uuuuuuuuuzwwsqr” using standard
site-swap
notation
531
Several period-5, 2-ball patterns
90001 12223 30520 14113
A story relating juggling with number theory…
The Pact
(1400 C.E.)
In the first year of the new century when the Kings of Onom and Laud each decreed the annual juggling period to be 1, a peace treaty was signed…
A Tale of Two Kingdoms
(first studied by E. Tamref)
Values of Culture 1 (Onom)
1. Annual Juggling Ceremony
Values of Culture 2 (Laud)
1. Annual Juggling Ceremony
A Tale of Two Kingdoms
(first studied by E. Tamref)
Values of Culture 1 (Onom)
1. Annual Juggling Ceremony 2. Orderly —1 period per year, starting with 1, then 2, 3, etc.
Values of Culture 2 (Laud)
1. Annual Juggling Ceremony 2. Orderly —1 period per year, starting with 1, then 2, 3, etc.
A Tale of Two Kingdoms
(first studied by E. Tamref)
Values of Culture 1 (Onom)
1. Annual Juggling Ceremony 2. Orderly —1 period per year, starting with 1, then 2, 3, etc.
3. Sequential & Complete — Juggling performances start with all patterns for 0 balls, then 1, 2, 3, etc.
Values of Culture 2 (Laud)
1. Annual Juggling Ceremony 2. Orderly —1 period per year, starting with 1, then 2, 3, etc.
3. Sequential & Complete — Juggling performances start with all patterns for 0 balls, then 1, 2, 3, etc.
A Tale of Two Kingdoms
(first studied by E. Tamref)
Values of Culture 1 (Onom)
1. Annual Juggling Ceremony 2. Orderly —1 period per year, starting with 1, then 2, 3, etc.
3. Sequential & Complete — Juggling performances start with all patterns for 0 balls, then 1, 2, 3, etc.
4. Individuality — Monistic presentation: 1 performer per ceremony
Values of Culture 2 (Laud)
1. Annual Juggling Ceremony 2. Orderly —1 period per year, starting with 1, then 2, 3, etc.
3. Sequential & Complete — Juggling performances start with all patterns for 0 balls, then 1, 2, 3, etc.
4. Complementarity — Dualistic presentation: 2 performers per ceremony
The Pact
(1400 C.E.)
In the first year of the new century when the Kings of Onom and Laud each decreed the annual juggling period to be 1, a peace treaty was signed. To strengthen this new union, the pact was to be celebrated each year at a banquet where each kingdom would contribute a juggling performance obeying its own principles. However, to symbolize their equal status and mutual regard, each performance must consist of an equal number of juggling patterns.
Year One
For example, at the end of the first year, the solo juggler of Onom performed all period-1 juggling patterns with 0, 1, 2, 3, and 4 balls, while the juggler duet from Laud first performed all period-1 patterns with 0 and 1 ball and then 0, 1, and 2 balls . (Total number of patterns for each: 5)
Year Two
00 11 20 02 22 31 13 40 04 33 42 24 51 15 60 06 44 53 35 62 26 71 17 80 08
Year Two
Also, at the end of the second year, the following were performed at the banquet —the solo juggler of Onom performed all period-2 juggling patterns with 0 to 4 balls, while the juggler duet from Laud first performed all patterns with 0 to 2 & then 0 to 3 balls. (Total number of patterns for each: 25) 0 balls 1 ball 2 balls 3 balls 4 balls
A Tale of Two Kingdoms
(first studied by E. Tamref)
Values of Culture 1 (Onom)
1. Annual Juggling Ceremony 2. Orderly —1 period per year, starting with 1, then 2, 3, etc.
3. Sequential & Complete — Juggling performances start with all patterns for 0 balls, then 1, 2, 3, etc.
4. Individuality — Monistic presentation: 1 performer per ceremony
Values of Culture 2 (Laud)
1. Annual Juggling Ceremony 2. Orderly —1 period per year, starting with 1, then 2, 3, etc.
3. Sequential & Complete — Juggling performances start with all patterns for 0 balls, then 1, 2, 3, etc.
4. Complementarity — Dualistic presentation: 2 performers per ceremony
Question
Will this harmonious arrangement continue indefinitely for the Kingdoms of Laud and Onom?
For years 3 and beyond, as the sanctioned periods continually increase by one, can joint ceremonies be planned so that each abides by their own rules and each presents the same number of juggling patterns?
0 balls
Period-3 Juggling Patterns
1 ball 2 balls… 1 7 19
Period-1
# of Balls: # of Patterns: 0 1 1 1 2 1 3 1 4 1
Year Two
Also, at the end of the second year, the following were performed at the banquet--the solo juggler of Onom performed all period-2 juggling patterns with 0 to 4 balls, while the juggler duet from Laud first performed all patterns with 0 to 2 & then 0 to 3 balls. (Total number of patterns for each: 25) 0 balls 1 pattern 1 ball 3 patterns 2 balls 5 patterns 3 balls 7 patterns 4 balls 9 patterns
Period-2
# of Balls: # of Patterns: 0 1 1 3 2 5 3 7 4 9
Period-3 Juggling Patterns
Where have we seen these numbers before?
0 balls 1 ball 2 balls… 1 7 19
Period-3
# of Balls: # of Patterns: 0 1 1 7 2 19 3 37 4 61
Again, Period-2
• Patterns per ball are odd numbers • A balanced juggling performance: • (1+3+5+7+9) = 25 = (1+3+5) + (1+3+5+7) • Recall: (the sum of the first k odds) =
k
2 So: 5 2 = 3 2 4 2
Initial sum = Middle sum
(1+3+5+7) = 16 = (7+9)
Initial & Middle sums for 2k +1
k
0 1,3,5, Pythagorean Triples
(3k)(k+1) +1
k
0 • Sequence: 1 • Examples: 7 19 37 61 91 … Initial Sums: Middle Sums: 1, 8, 27, 64, 125,… 7, 26, 63, …19, 56,117,…37,… •
Euler:
No initial and middle sums are equal. (proven in the equivalent form of
a
3
b
3
c
3 has no solutions in non-zero integers
a
,
b
, and
c
)
The future of the “Two Kingdoms” is resolved through number theory
T.F.A.E.: 1.
a n
b n
c n
2.
a n
c n
b n
3. For the specific sequences of the form (initial sum) = (initial sum) – (initial sum) (
k
1)
n
k n
k
0 (initial sum) = (middle sum)
Conclusion
Theorem 5: (Graham, et. al., 1994) The number of period-n juggling patterns with fewer than
b
Theorem 6: T.F.A.E.: 1. The monistic and dualistic sequential periodic juggling pact can not be satisfied for years 3, 4, 5, … 2. F.L.T.
F.L.T.
(It is impossible to separate a cube into two cubes, or a fourth power into two fourth powers, or in general, any power higher than the second into two like powers. I have discovered a truly marvelous proof of this, which this margin is too narrow to contain.) Fermat/Tamref
Conclusion: “Add one more to your list of applications of F.L.T.”
Thus ends our exercise in: Juggling Sequences with Number Theory
& “A Tale of Two Kingdoms” Stephen Harnish [email protected]
Website sources
• Images came from the following sites: http://www.sciamdigital.com/index.cfm?fa=Products.ViewBrowseList
http://www2.bc.edu/~lewbel/jugweb/history-1.html
http://en.wikipedia.org/wiki/Fermat%27s_last_theorem http://en.wikipedia.org/wiki/Pythagorean_triple http://en.wikipedia.org/wiki/Juggling
Another story-line from the 14
th
C
• Earlier in 14 th C. Onom, there had emerged a heretical sect called the neo-foundationalists. They valued orderliness and sequentiality, but they also had more progressive aspirations performer’s juggling routine would be orderly and sequential but perhaps NOT based on the foundation of first 0 balls, then 1, 2, etc. These neo-foundationalists might start at some non-zero number of balls and then increase from there.
• However, they were
neo-foundationalists
patterns from the traditional, more
foundational
—the solo in that they would only perform such a routine with m to n number of balls (where 1 < m < n) if the number of such juggling patterns equaled the number of display of 0 to N balls (for some whole number N).
• For how many years (i.e., period choices) were these neo foundationalists successful in finding such equal middle and initial sums of juggling patterns? • (Answer: Only for years 1 and 2).