Off on a Tangent 
A Fortnightly Electronic Newsletter
from the Hope College Department
of Mathematics 
October 19, 2011  Vol. 10, No. 3

http://www.math.hope.edu/newsletter.html 
This week's
colloquium takes a look at an old "proof" for the four color theorem 
Title: Alfred
Kempe's "Proof" of the Four Color Theorem 

Speakers: Tim Sipka, Alma
College 

Time: Thursday,
October 20 at 11:00 am 

Place: VWF 102 
Next week's
colloquium 
Title: Lights
Out: Some Puzzles, Some Results, and Some Questions 

Speakers: Darin Stephenson,
Hope College 

Time: Tuesday,
October 25 at 4:00 pm 

Place: VWF 104 
Help out MDY's
Mathemagicians in the upcoming Relay for Life 

In the wake of Mary DeYoung’s death after a brief
battle with cancer this past summer, many students are looking for ways
to honor and celebrate her life. One of these opportunities presents itself
in this year’s Relay for Life at Hope College. A team has been formed for
all of us to remember Mary DeYoung and to help raise money to fight this
horrible disease. You can support the team in any of the following four ways:
Thanks for helping us work towards a world with less cancer and more birthdays! 
MATH Challenge 
Math in the News: Scientists use Twitter to analyze public heath trends 

Who would ever think that "omg i think
i have the flu going home bfn" would be of value to science. Well
according to a recent report from Discoveries
and Breakthroughs Inside Science, computer scientists at John Hopkins
University are using the online social networking and microblogging service
to track public health trends. "There’s a lot of different patterns we were able to uncover,” said Mark Dredze (Johns Hopkins), “so for example we were able to track the influenza rate in the United States over time just by counting how many times people are talking about the flu.” 
Problem Solvers
of the Fortnight 

In our last problem of the fortnight
we saw that Sally began
to solve a problem at the time between 4:00 and 5:00 p.m. when the clock's
hands are together. She finished when the minute hand is opposite
the hour hand. How many minutes does it take her to solve the problem,
and when does she finish it? Give exact answers in terms of fractions
of minutes (i.e. no decimal approximations). Congratulations to Lauren Aprill, Ryan Martinez, Lute Olsen, Jessica Hulteen, Jake Blysma, Craig Toren, Krisen Slotman, Corinna Schmidt, Danielle Maly, Erice Budge, Emily Scott, Allison Leigon, Anna Filcik, Lisa McLellan, Kristen Bosch, Bryce Ciroshek, Pete Stuckey, Hunter Ford, Brant Bechtel, Sarah Prill, David Dolphin, Andrew Borror, Morgan Smith, Daniel Langholz, Shinnosuke Kondo, Scott DeClaire, Melanie Leonard, Justin Kammeraad, Allie Benson, Josh Swelt, Kevin Olson, Andrew Brooks, Nicole Zeinstra, Tim Lewis, Tim Cooke, Matt Folkert  all of whom correctly determined the exact starting and ending time of the exam in the last Problem of the Fortnight. 
Problem of the
Fortnight 

You have ten stacks of coins, each consisting
of 10 new dollar coins. One entire stack of coins is counterfeit, but
you do not know which one. However, you do know the weight of a genuine
dollar coin, and you are also told that each counterfeit coin weighs one
gram more than it should. Your kind chemistry professor agrees to let
you weigh the coins on one of the electronic scale in the chem lab. What is the smallest number of weighings necessary to determine which stack is counterfeit, and how do you do it? Attach a counterfeit dollar coin to your solution, and drop it in the Problem of the Fortnight slot outside Professor Pearson's office (VWF 212) by 3:00 p.m. on Friday, October 28. As always, be sure to include your name as well as the name(s) of your professor(s)  e.g. Bo Guscoins, Professor Cown TerFit  on your solution. 
Off on a Tangent 