"Mathematics is the process of turning coffee into theorems" Paul Erdös
This series is supported entirely by private donations.
Wednesdays at 4:00 p.m.

Coffee at 3:45 p.m.

FEB. 4 THE MINISTRY OF SILLY WALKS
Thomas Mattman, Mathematics and Statistics,
CSU Chico
The pattern your footprints leave when you walk along the beach is
an example of a Frieze pattern. Using this idea, Conway has given the
Frieze patterns names such as “jump” and “spinning hop”.
If you’ve ever tried performing “spinning sidle” for friends
or students, you’ll know that some of these walks are pretty silly. But
are they REALLY silly? For this we turn to the masters of silliness, the British
comedy troupe Monty Python’s Flying Circus. We will analyse the “Ministry
of Silly Walks” skit to understand which of Conway’s walks are truly
silly.
FEB. 11 MATH 180 PROJECTS
Bill Barnier, Professor of Mathematics, introduces students Jessica Balli, Cory
Champagne, Frank Cortese, Lori Dempel, Kim Ginthum, Kristen Holub, Melissa Newcomb,
and Sean Pearson from his Fall 2003 Math180 class who will present Mathematica
projects examining drug dosage, biology, Pythagorean triples, water buckets,
life expectancy, the lottery, blood alcohol level, and truth tables. Pizza
after talk in Darwin 127
FEB. 18 A METAPROBLEM
Bill Barnier, Professor of Mathematics,
SSU
will present the metaproblem: How to find a really nice cubic function. After
defining “really nice” he will derive an elliptical solution similar
to a circular derivation of Pythagorean triples.
FEB. 25 MATHEMATICS, NAVIGATION, AND THE GLOBAL POSITIONING
SYSTEM
Bob Kleinhenz, Consultant
The talk is centered on the mathematics that lie underneath the Global Positioning
System (GPS). The discussion will cover the basic measurements performed by
a GPS receiver along with the model used to convert each measurement into a
position solution. Along this way, elementary notions of orbits and earth coordinate
systems are discussed. The dominant error sources in the GPS mathematical model
are mentioned and the methods of overcoming these errors are presented. The
talk concludes with a brief discussion of the algebraic and spectral properties
of PN codes. PN codes are broadcast by GPS satellites and serve as identification
for each satellite.
MARCH 3 PROBLEMS ON THE BORDER BETWEEN GEOMETRY & NUMBER
THEORY
Don Chakerian, University of California Davis
We discuss some problems (mostly unsolved) concerning configurations of points
that are at integer or rational distances from each other. For example, is there
a point inside a unit square where distances to the vertices are all rational
numbers?
MARCH 10 DEMONSTRATIONS OF STABILITY: UNDERSTANDING BIFURCATIONS
Elizabeth Burroughs, Mathematics, Humboldt State University
If you sit in the front row, you might get wet! Using such household items as
a tennis racquet, soap bubbles, a hairdryer, and a glass of water (not all at
the same time), we will consider a variety of stability problems. A physical
system is described as stable when a “small” perturbation to a steady
state settles back to that steady state, and unstable otherwise. A physical
system undergoes a bifurcation when there is an abrupt change in the nature
of the solution as a given parameter changes. Because bifurcations are associated
with an exchange of stability, we can locate bifurcations by tracking the stability
of solution branches. We will consider the three simplest bifurcations: the
turning point bifurcation, the Hopf bifurcation, and the pitchfork bifurcation,
and study a simple equation that describes each one.
MARCH 17 MAGIC SQUARES AND ORTHOGONAL ARRAYS
Donald Kreher, Mathematics, Michigan Technological University
A magic square is an n by n array of integers with the property that the sum
of the numbers in each row, each column, and the main diagonals is the same.
This sum is the magic sum. Magic squares have had a long and colorful history.
They have attracted the attention of emperors, hobbyists, magicians, and even
mathematicians. In this talk we give an introduction to recursive constructions
in the context of magic squares and orthogonal arrays.
MARCH 24 MATHEMATICAL ANALYSIS OF DNA SEQUENCES
Elaine McDonald, Mathematics & Holly Skolones, Biology, SSU
will present their collaborative work using hidden Markov models applied to
sequence alignment problems. This talk will begin with a brief introduction
to biology and probability models, and move to a description of the algorithms
used to find probable alignments between different DNA sequences. Holly will
describe how she uses these powerful programs, routinely used by biologists,
to identify bacterial species compositions of vernal pools. This talk is intended
for an interdisciplinary audience of mathematicians, computer scientists, and
biologists, including students. Pizza after talk in Darwin 127
MARCH 31 Cesar Chavez Day  no talk
APRIL 7 Spring break  no talk
APRIL 14 PENROSE TILINGS
Brigitte Lahme, Mathematics, Sonoma State University
The familiar tilings of the plane (or your kitchen floor) are periodic: They
repeat the same pattern over and over again. Penrose tilings are infinite tilings
that cannot tile the plane in a periodic manner. They are interesting to chemists
because they model a recentlydiscovered structure called quasicrystals, and
account for a previouslyunexplainable 5fold symmetry which these structures
exhibit. Given a set of Penrose tiles, there are uncountably many ways in which
those tiles can fill the plane — none of them periodic. We will explore
properties of Penrose tilings, ways of generating them, and difficulties in
working with such an unwieldy object!
APRIL 21 USING MATH IN CELL BIOLOGY: HOW DO CALCIUM CHANNELS
WORK?
Bori Mazzag,Computational Biology, College of William & Mary
This talk will explore an example of how mathematics can be useful to molecular
biologists. We will build a simple probabilistic model of a channel opening,
releasing calcium and closing, and discuss how we can simulate such a model
numerically. We will investigate how specific biological assumptions about the
model translate into mathematical statements, and we will examine the prediction
of the modified model. At the end of the talk, we will sneak a peak at related
biological questions that can be answered using the introduced methods. The
talk will assume no previous biology, and the mathematics employed will be accessible
to a general audience.
APRIL 28 MATH FESTIVAL DAY SEARCHING
FOR THE SHORTEST NETWORK
Ronald Graham, Mathematics, UC San Diego
There are many situations in which one would like to connect a collection of
points in some space by a network having the minimum possible total length.
Such problems have a long and distinguished history, and occur in such areas
as the design and analysis of telecommunications networks, oil pipeline networks,
and heating and air conditioning duct systems, algorithms for molecular phylogenetics,
and the layout of circuits on VLSI chips, to name a few. In this talk, we survey
what is known and what is not known about this problem, and how it has been
impacted by current developments in theoretical computer science.
MAY 5 UNCOVERING THE LATENCY IN LATENT VARIABLE MODELS
Karen Nylund, Education & Information Studies, UCLA
Latent variable modeling is a statistical modeling framework that is widely
used in the social sciences to study variables that are not directly observable.
This studentfriendly talk will explore latent variable models and will include:
defining what a latent variable is (which include those one might know, but
not consider to be a latent variable), their relationship to traditional regression
models, and practical examples from education and psychology. These examples
will demonstrate the flexibility and wide application of latent variable models.
A basic understanding of regression is the only statistical background needed
to follow this talk. Pizza after talk in Darwin 127