Off on a Tangent
A Fortnightly Electronic Newsletter from the Hope College Department of Mathematics
 January 22, 2016 Vol. 14, No. 8

Lights Out Colloquium 

Title: Lights Out: Some Puzzles, Some Results, and Some Questions
Speaker: Darin Stephenson, PhD, Hope College Math Department
Time:  Tuesday, January 26 at 4:00-4:50 pm
Place:  VanderWerf 102

In the “Lights Out” puzzle, the solver seeks to turn off all of a set of lights (often represented by the vertices on a graph) by pressing a series of buttons, each of which has a certain predefined effect on the lights.  The lights each have an “initial state” (typically “on” or “off”), and an initial configuration of states is called winnable if there is a process for turning off all of the lights.  The solution to any specific version of this puzzle can be phrased in terms of matrix algebra.  Our overall goal is to study this problem in generality, and, eventually, to characterize the solvable initial configurations for certain families of graphs.  In this talk, we will provide a survey of the classical Lights Out puzzle, discuss many generalizations and some known results, discuss applications of this and related problems to machine learning, and give a few questions that may serve as motivation for collaborative faculty-student research in Summer 2016.

Upcoming Colloquia

The following colloquia are currently on the schedule for this semester. Others will be added as the semester goes along.
  • Tuesday,  February 9 at 4-5pm, Feryal Alayont, GVSU
  • Tuesday, February 23 at 4-5pm, Stephanie Edwards, Hope College
  • Tuesday, April 19 at 4-5pm, Eric Nordmoe, Kalamazoo College

Math Club News

The Math Club invites you and your friends to The Theory of Everything on Friday, February 5 at 9:00 pm in Winants Auditorium in Graves Hall.  The movie features the life of Stephen Hawking, one of the world's foremost physicists.  The movie tells the heartfelt story of Stephen falling in love with arts student Jane Wilde and raising a family, all while his body is failing him and his popularity soars as his brilliant ideas become widely known.

For more info on the Hope Math Club's latest and greatest activities, visit their FaceBook page (and request to join the group).

Kaggle Data Science Bowl

The goal of the Second Annual Kaggle Data Science Bowl is to transform how we diagnose heart disease by developing mathematical algorithms that automatically calculate heart volume from MRI scans (using about 27 Gb of MRI scan data!).  The data we are analyzing looks like this.  The next team meeting will be Saturday, January 23 at 3 pm in VanZoeren 276 (bring a computer).  If you are interested in joining the team and have taken multivariable mathematics 1 or have Python programming experience, please contact Paul Pearson (

Math in the News: Building a better snowman

Next time you go out to build a snowman, you might want to consult with Dr. James Hind of Nottingham Trent University since he has developed a formula to help you develop a better snowman. He says the snowman should be 64 inches tall with snowballs of 31, 20, and 12 inches in diameter. (I guess compression takes care of the missing inch.)

His formula, shown on the left is also designed to give scores for the purity of the snow, facial features, and accessories besides size and proportion. He also suggests making the snowman out of snow that is 32 degrees Fahrenheit or less. (I think otherwise it would be a puddle man!)  Click here to read more about how to make the ultimate snowman.


Math Road Trip

Here are two opportunities this semester for Mathematics and Mathematics Education majors to attend conferences in Michigan. On Saturday, February 27 the Math in Action at Grand Valley State University presents lively and informative discussions of current issues in mathematics education while providing an opportunity for practicing PreK – 12 teachers, prospective teachers, curriculum directors, and college and university faculty to share ideas, concerns, and resources. The conference consists of six hour-long sessions with eight separate interactive presentations during each.

On Saturday, March 19 the MI‐AMTE Conversations Among Colleagues will be held at Western Michigan University. This conference was designed to facilitate conversations between and among mathematicians, mathematics educators and leaders in mathematics education related to mathematics education and the preparation and continuing professional development of teachers of mathematics PreK‐College. 

For Hope College Mathematics and Math Education Majors, student registration fees and transportation via a Hope College Van will be covered by the Math Department. Both trips are being organized by Dr. Mann.  Drop him an email
at or stop by his office, VanderWerf 213, to find out more or reserve your seat in the van. Contact Dr. Mann by the following date(s) to participate with department funding: Conversation Among Colleagues by Thursday, January 28, Math in Action by Thursday, February 11.

Problem of the Fortnight

A square of side length 2 and a circle share the same center. The total area of the regions that are inside the circle and outside the square is equal to the total area of the regions that are outside the circle and inside the square. What is the radius of the circle?

Write your solution (showing all relevant work) on circular square and drop it in the Problem of the Fortnight slot outside Professor Mark Pearson's office (VWF 212) by 3:00 p.m. on Friday, January 29.  As always, be sure to include your name and the name(s) of your math professor(s) -- e.g. Moe Mentum, Professor Sara Bellum  --- on your solution.

If you don't know where you are going, any road will take you there.

from Alice in Wonderland by Lewis Carroll

Off on a Tangent