Lecture at 4:00 PM in Darwin 108, Coffee in Darwin 108 Foyer at 3:40 PM

FEBRUARY 30-1 MATRICES: THEY ARENšT JUST FOR BREAKFAST ANYMOREGerhard Paseman, Prado Internet Access, Inc., Hayward, will take us on a personal journey exploring a problem involving determinants. Side tracks into combinatorics, algorithms, and applications are involved. Some results and current status in combinatorial matrix theory will be given. Prerequisite: Must know what the determinant of a matrix is. Warning: Some personal reminiscences involved!

FEBRUARY 10TRIANGLES, BRAIDS AND THE N-BODY PROBLEMRichard Montgomery, University of California, Santa Cruz (and SSU alumnus), will discuss the Three-Body Problem, which is an unsolved, and perhaps unsolvable, problem left over from Newton's day. He will explain how the shape space for planar triangles forms a two-sphere, and why this sphere and its geometry are relevant to the three-body problem. He will finish by describing the generalization of this shape space to N-gons and the N-body problem and how the braid group (important in knot theory) enters into the picture.

FEBRUARY 24CENSUS OR SAMPLING: THE SURPRISING TRUTHABrian Jersky, Mathematics, SSU, will show why sampling is a better way to find out how many people there are in the United States than trying to count them all. This is without a doubt scientifically true. However, there are political reasons why some people would prefer a census rather than a sample, and he will briefly mention these too. It will be up to the audience to decide which method they prefer.

MARCH 3THE PASCH PROPERTY AND PARAMETRIC EQUATIONSSteve Wilson, Mathematics, SSU, will show how the Pasch Property can be used to tack down a tricky little detail in the definition of arc length, and how this problem can lead to the theories of parametric equations and convex bodies.

MARCH 10HYPATIA: HERETIC? MARTYR? MATHEMATICIAN?Edith Mendez, Mathematics, SSU, in conjunction with Women's History Month, will discuss the historical figure of Hypatia, who is known more for her gruesome death in 415 C.E. than her life. As we sift through the legends surrounding her, do we find a heretic, a martyr or a mathematician?

MARCH 17ENUMERACY: THE ART OF LITERATE COUNTINGTom Roby, Mathematics, Cal State Hayward, will explain that there's more than one way to count a set. Doing so often leads to interesting proofs of equations that come up all over elementary and advanced mathematics. Often such proofs can be expressed as a story. For example, to pick a subcommittee of 3 from a ten-member committee is the same as picking 7 members NOT to be on the committee, so "10 choose 3" is the same as "10 choose 7", or generally "n choose k" is the same as "n choose (n-k)". He will consider a variety of identities with particularly beautiful enumerative proofs.

MARCH 24WHAT IS THE LEBESGUE INTEGRAL AND WHY SHOULD YOU CARE?JClement Falbo, Mathematics, SSU, before he rides off into the sunset of retirement, will give an introduction to countable and uncountable sets, sets of measure zero and the measure of a set on the x-axis; how Lebesgue made his own case for the superiority of his integral over the Riemann Integral; and what kind of functions are Lebesgue Integrable, but not Riemann integrable. He will also discuss applications.

MARCH 31ŗTHIS ISNšT HOW I LEARNED MATH IN HIGH SCHOOL:˛ THE INTERACTIVE MATHEMATICS PROGRAMRick Marks, Mathematics, SSU, will present a sample unit and a four-year overview of the IMP, an innovative, problem-based high school curriculum designed to help all students learn powerful mathematics.

APRIL 7SPRING RECESS

APRIL 14SOAP FILMS IN NATURE AND IN MATHEMATICSRoseanna Pearlstein, University of California, Santa Cruz, will discuss some very beautiful familiar objects which arise in nature and are likely to be familiar to most people: soap films. She will try, with the help of colorful pictures, to give a feeling for why soap films are especially fascinating to mathematicians. Without going into technicalities, she will try to motivate two major mathematical questions related to the study of soap films: existence and uniqueness.

APRIL 21

HOW TO WALK UP STAIRS (Tentative)Jeff Sachs, Wagner Consultants, Santa Clara [Abstract to follow]

APRIL 28GEOMETRY FROM THE CUBEšS POINT OF VIEWDon Chakerian, Mathematics, University of California, Davis (Retired), will explain how viewing a solid geometry problem in the framework provided by an appropriate auxiliary cube often results in surprising simplifications. He will give some examples involving triangles, tetrahedra, and the packing-spheres problem.

MAY 5AN ADVENTURE IN MODELINGJeffrey Housman and Rebecca Schram, current Math majors at SSU, will discuss a project they have been working on: a look at elementary flow models in heat, electricity and water. Their model will use finite differences, finite element, and analytical methods for solution.

Parking permits ($1.50) are required Monday through Thursday 6am -10pm. No public parking is permitted in reserved spaces at any time.