# Are you a fair weather fan?

This past weekend my husband and I went first home football game of the season for the Iowa Hawkeyes.  I was excited about the game until I saw the forecast for this past Saturday . . . every day on the news it seemed like the high temperature for the day kept creeping higher and higher.  Finally, on Thursday of last week the air temperature was forecast to reach 94 degrees and the University of Iowa athletic department began posting tips on now to start hydrating now for the game on Saturday.

I called my husband and work and our conversation went something like this:

Me: Did you see the forecast for Saturday?  I think its supposed to be dangerously hot . . .

Husband: Are you trying to bail?

Me: No!  I’m just worried about the heat . . . they said to start hydrating today.

Husband: You’re a fair weather fan!

Really?!? A fair weather fan?

We went.  We had a great time.  The Hawkeyes won.  I didn’t melt.  All in all it was a successful Saturday.

But my experience on Saturday got me thinking about a little thing called the heat index . . . I always thought it of it as the wind chill of really, really hot temperatures.  So, I decided to do a little digging to

1. Find out about the heat index.
2. Prove to my husband that I am not a fair weather fan.

According to the National Weather Service, the calculation of the heat index is a regression equation . . .which quite frankly seemed a little complicated for this blog (but if you’d like to see it, look here).

But, I did think that it was interesting that there was an important note when reading the heat index table . . . the NWS warns that the heat index can only be accurately calculated when the humidity and air temperature are represented on the chart.  In other words, this is a domain and range issue.

There are many situations in mathematics when we’d like to model a particular phenomenon. . .  (heat index, racing times, time-lapse modeling) just to name a few.  And in those situations it does not make sense to have the domain and range be all real number.  Sometimes it doesn’t make sense because the situation represented doesn’t make sense (i.e. negative time) and sometimes it doesn’t make sense because the function will not fit the data as closely if we allow the domain to be all real numbers (as in the case of the racing times).

This past Saturday the temperature at game time was 90 degrees with about 60% humidity . . . we stayed until the end of the third quarter when the Hawkeyes were winning 31-0.  So, what say you . . . am I a fair weather fan?

P.S. If you’re new here, let me let you in on a little secret . . .I love to think about the weather.  Don’t all midwesterners?  Check out a few more weather related posts here and here and here.

# Math for High Ability Learners–at the University of Iowa

Just a quick note to let you know that I’m teaching Math for High Ability Learners, a 3 week virtual workshop offered at the University of Iowa beginning January 21.  The workshop is worth 1-hour of graduate or undergraduate credit from the University of Iowa.

The focus of the course will be designing mathematics lessons to meet the needs of both the typical and the high-ability learners in K-12 mathematics classrooms.

To get a better idea of the coursework here’s the syllabus:

I hope you’ll join me!

# Talking the Talk and Walking the (Math) Walk

A few days ago I was poking around my alma mater’s website (Go Panthers!) and came across this math walk:

unimathwalk

(This math walk was originally posted at: http://www.uni.edu/math/sites/default/files/pdfs/unimathwalk.pdf )

I thought it was such a cool idea that I wanted to create a math walk of my own!  (So I did).

I know that not all of you will be walking around Iowa City or The University of Iowa’s campus, so I thought I’d bring the math walk to you.  I’d encourage you to:

1. Try my virtual math walk

and then . . .

2. Get some friends, or a class, or your family and create a math walk of your own.  When you do, send it to me (katherine-degner@uiowa.edu) and I’ll post the math walks on my blog.  Soon no one will be able to walk around without “thinking math.”  Wouldn’t that be great!

My University of Iowa/Iowa City Math Walk

I work at the Belin-Blank Center, on the University of Iowa Campus . . . which is here:

So, I headed out of the building toward the Pentacrest (more on that later) and the Old Capital.

I got no more than half a block when I ran in to this!

The official name of the sculpture is “Ridge and Furrow,” although many people at the University of Iowa refer to it as the “brain sculpture.” (For obvious reasons!).   It was carved by artist Peter Randall-Page.  The artist says that it is many up of one, continuous ridge flanked by v-shaped furrows.

1. The description made me think of the mobius strip.  In other words, think of this as one great big twisty infinity symbol (which is a mobius strip, just FYI).  I’m also wondering if we could cut the continuous ridge and stretch it out into a straight line, how long would it be?  How could you estimate this?

As I headed toward the Pentacrest, I couldn’t help but notice the bricks I was walking on.

They looked like this.  I also noticed they tessellated the plane.

2. Which made me wonder, how many other ways could I arrange these standard sized bricks so that they would continue to tessellate the plane?  And, what wallpaper pattern does this tessellation belong to?  Which really asks, “What type of symmetry is being used to create this pattern?”

In the middle of my math walk many classes let out and I was flooded by students.  And I saw these two:

3. Which made me wonder, what are the chances of that happening?  (In case you can’t tell from the picture, the two men are dressed exactly.the.same. blue t-shirts, khaki shorts).  This question takes the form of “if you have 3 pairs of blue socks, and 2 pairs of green socks, what are the chances that . . .”

I was headed to the Pentacrest because I knew about a secret on the Pentacrest.  I thought I was the only one that knew, until I found this.   Anyway, “what’s the secret?” you might ask.  Well, the University of Iowa Pentacrest is home to the largest walnut tree in the state of Iowa!  Here it is:

This leads me to my next (maybe obvious? question).

4. How tall is the tree and how in the world do you measure it?

As promised at the beginning of the post, I have a little bit more to tell you about the Pentacrest.  First, you may or may not know that penta- means 5.  This might lead you to believe that the Pentacrest has five buildings.  And if that’s where your thoughts lead you, you’d be right!  The Pentacrest is a little piece of lawn which houses 5 university buildings (one of which is the Old Capitol).  I tried to take a picture of the Pentacrest, but the truth is the professional photographers, that took ariel pictures just do a much better job.  See:

Do you also see how it kind of looks like a pentagon?  No, not THE Pentagon (which is a regular pentagon), but it does kind of look like a pentagon, except that the Old Capital isn’t a vertex.  Anyway, this leads me to my last question on my math walk:

5. Is there a way to get to each of the 5 buildings using the sidewalks provided, such that I go to all buildings and walk on each sidewalk exactly once?  (Kind of reminds you of the Bridges of Konigsberg Problem, doesn’t it?)

Whew!  You made it!  Happy math walking!

P.S. Once I started “math walking” I just couldn’t stop, so I snapped these pictures as I was walking home from work:

I’m wondering:

6. What percent of the house is covered in ivy?

7. Is that an equilateral triangle?  How could we find out?