Off on a Tangent
A Fortnightly Electronic Newsletter from the Hope College Department of Mathematics
   October 3, 2007 Vol. 6, No. 3  
http://www.math.hope.edu/newsletter.html


Colloquium Tomorrow

Title:

Death and Dismemberment in a Petri Dish:
Modeling a Three-Level Interaction Using Nonlinear Dynamics
Speakers:

Tim Boman, Ryan Johnson, Bryan McMahon, and John Molenhouse, Hope College students
Time:

Thursday, October 4 at 4:00 p.m.
Place:

VZN 240


Abstract: 
We studied a three-level food chain (a tri-trophic interaction) between Tall Fescue grass, Fall Armyworms, and parasitic wasps and how this relationship changes when a fungal endophyte (a fungus that lives inside the grass) is introduced. Tri-trophic interactions are not only interesting because of their intriguing dynamics, but also because there are few tri-trophic models that have been fully analyzed. Using three nonlinear differential equations, one equation for each population, we attempted to analyze this system and predict the population patterns in environments with and without the fungal endophyte. Our goal was to find the fixed points of these systems, which are where the populations settle down into an unchanging equilibrium. Some of these fixed points were easily analyzed, while others required a novel approach. Aside from the mathematical analysis, we also got our hands dirty working with the caterpillars and wasps (the grass was pretty clean).


Colloquium Next Tuesday


Title:

Optimizing a Volleyball Serve
Speaker:

Dan Lithio, Hope College student
Time:

Tuesday, October 9 at 4:00 p.m.
Place:

VZN 240



Abstract:
  An optimal volleyball serve is one that gives the receiving team minimal time to react.  That is, it is one in which the ball goes over the net and hits the floor in the shortest amount of time.  In this talk I'll develop a model for the flight of a volleyball acted upon by gravity, air resistance and spin.  Coefficients of drag and spin were determined via crude but ingeniously effective experiments, and the trajectories of theoretical models were compared with actual trajectories of volleyballs shot from a launcher.  Finally, we use the model to find the optimal serves while varying the height of the serve, the amount of spin, and the total distance traveled.


Tea Time


As part of our colloquium series, the mathematics department will host a "tea" in the Reading Room (VWF 222) at 3:45 p.m. on Thursdays before colloquia.  If tea isn't really your cup of tea, have no fear -- we'll provide some other beverages and snacks, too.  So please join us for a little food and fellowship before you go to the colloquia.  We encourage you to be environmentally friendly by bringing a cup for beverages, but we'll provide cups if you can't bring your own.  Please join us for tea on Thursdays before colloquia!  It's a great time to chat with the speaker, your professors and other students!



Fall Math Competitions


Two mathematics competitions that take place each fall are the MATH Challenge and the Putnam Exam.  Students can compete in either of these competitions without leaving Hope's campus.  Information about each of these follows.



The MATH Challenge

The 2007 Michigan Autumn Take Home Challenge (or MATH Challenge) will take place on the morning of Saturday, November 3 this year.  Teams of two or three students take a three-hour exam consisting of ten interesting problems dealing with topics and concepts found in the undergraduate mathematics curriculum.  Each team takes the exam at their home campus under the supervision of a faculty advisor. 

The department pays the registration fee for each team and will provide lunch to participants afterwards. The sign-up deadline is Monday, October 22 at 4:00 p.m.  Interested students can sign up by sending Prof. Edwards an email at sedwards@hope.edu or by signing up on the list on her door (VWF 218).

A group of students may sign up as a team.  Individual students are also encourage to sign up; they will be assigned to a team on the day of the competition.  For more information, please talk with any member of the Mathematics Department or visit http://www.mcs.alma.edu/mathchallenge/, where you can also view old copies of the exam. 

The Putnam Exam

The William Lowell Putnam Mathematical Competition, administered by the Mathematical Association of America, is the most prestigious mathematical competition for undergraduates in the nation.  If you are interested in taking the 68th Annual Wm. Lowell Putnam Exam, you must email Professor Stoughton by 4:00 p.m. on Tuesday, October 9.   The date of the exam is Saturday, December 1, 2007. There is both a morning and an afternoon session of this exam; lunch will be provided by the mathematics department during the break.  For more information about the Putnam Exam visit http://math.scu.edu/putnam/. For questions and solutions from past exams visit http://www.kalva.demon.co.uk/putnam.html. 


MUMC


The Department of Mathematics at Michigan State University will host tenth annual Michigan Undergraduate Mathematics Conference (MUMC) on Saturday, October 27, 2007.  Hope College will be taking a group of students and faculty.  They will leave early in the day and return  in the evening.

Undergraduate students will be giving 20-minute oral presentations on many areas of mathematics, statistics or related disciplines. Such areas include undergraduate research projects, interesting class projects, history of mathematics, or expository talks on interesting mathematics.  Students are also encourage just to attend as there will be presentations on careers in mathematics, information about mathematics graduate programs and REU programs.

Students interested in attending need to sign up with Prof. Darin Stephenson by Monday, October 8 (he has a sign-up sheet outside his office door, VWF 219).  Visit the MUMC web page at http://www.lymanbriggs.msu.edu/mumc2007 for more information about the conference.


The Problem of the Fortnight


The Problem of the Fortnight has gone national!  More precisely, the Problem of the Fortnight will now be part of the national Problem Solving Competition.  The Hope College student who submits the greatest number of solutions from now until the end of the year will be eligible for a prize!

The problem for the upcoming fortnight involves a regular tetrahedron, a solid whose four sides are congruent equilateral triangles.  The problem is:

A regular tetrahedron has edges 36 units in length.  What is the altitude of the tetrahedron?  Give your answer in simplest radical form (i.e. x √ y form) and make sure you justify your answer.

Write your solution on a piece of paper,  fold it into a tetrahedron and drop it by Dr. Pearson's office (VWF 212) by noon on Friday, October 12.  As always, be sure to write your name, the name(s) of your professor(s), and your math class(es) -- e.g. Al T. Tude, Professors Newton and Leibniz, Math 131 and 132 -- on your solution.


Problem Solvers of the Fortnight


A number of students brushed off their trigonometry skills and were able to come up with a correct solution to last week's problem of finding the length of L in terms of .  There are a number of ways to write a correct answer to this problem.  One way is

.

Congratulations to our problem solvers of the fortnight: Zachary Mitchell, Clint Jepkema, Lauren Steel, Jack Lepird, Kyle Topliff, Blair Williams, Katie Henveld, Benjamin Lewis, Joel Mulder, Joel Blok, Layne Fowler, Luke Wendt, Eddie Helderop, Jeffrey Meyers, Peter Doorn, Brian McLellen, Eric Lunderberg, Meghan Cook, Brian McMahon, Jeff Minkus, Katie Johnson, Forrest Gordon, and Chris Ploch.



Ask Elvis. . . .


Dear Elvis,
 
We heard you had your second surgery and that it went well.  We miss you coming by for your snacks here in the office.  Get well soon and come to see us!
 
Jil, Marlene and Cathy

Dear Jil, Marlene and Cathy,

Thanks for the get well wishes.  It is nice to be back in the office enjoying everyone's company and the delicious snacks that are made available to me. 

While I haven't been that active lately, I have been keeping my big ears open (and my big mouth shut).  I have heard three rumors of some interesting mathematical locations around campus. 
Does anyone else know any interesting mathematical things about the Hope College campus?  If so, let me know via email at  elvis@hope.edu.  I would also love to hear from you if you have any mathematical questions.

Your pal,





It's supposed to be hard. If it wasn't hard, everyone would do it. The hard... is what makes it great!
      ~ A line from A League of Their Own

Off on a Tangent