Friday, November 16, 2012

Magnificent Marshmallow Marvels 1 - Adventures in Civil Engineering

In 1991 when I was working for Bechtel in San Francisco, I participated in this program called Engineer’s Week. It took place in February, if I remember correctly, and it was around Valentine’s Day time. Bechtel encouraged their engineers for volunteer to participate in this outreach program. We went out to different schools and spent a couple of hours talking about what we did and led the students in a fun, hands-on project which supposed encouraged the students to see Math and Science as something other than hard or boring.

There were many projects to choose from, but I choose this one because I thought it would be fun and it was easy to get hands on the materials (for Engineer’s Week, I think we didn’t have to do anything except pick up the project supplies from an admin and show up at school). I don’t remember what the project was called, but this is what I call it.

Magnificent Marshmallow Marvels – Adventures in Civil Engineering

For this project, you need mini marshmallows and toothpicks. A lot of toothpicks. I suggest the Dollar Store/Dollar Tree, etc. for the toothpicks because you can get a box of 1000 toothpicks for $1 (you’d be amazed at how many boxes of these toothpicks a kindergarten or a 1st grade class will go through).

I start the class by talking about living in California, earthquakes in general, then why earthquakes occur and plate tectonics (depends on the grade). I always have a tangible premise for the project. Most often, we’re trying to build inexpensive, yet safe housing for the poor in countries such as China, Chile, etc. The team that builds the safest and tallest house/building wins.

  1. Mini marshmallows
  2. Toothpicks
  3. A shakable flat surface (bigger than shoe box size plastic container lids work great) 
1.       Create a cube with marshmallows and toothpicks.

2.       Create a body-centered-cubic cube with marshmallows and toothpicks.

3.       Place these two cubes on a flat, shakable surface (most often, it’s a plastic container lid I find in class), secure them in place (holding on to them with the lid or lightly tape the bottom toothpicks to the lid) and shake them to see how they react to an “earthquake” of your creation.
4.       Try to build another level on top of the ground level housing.

5.       Without much effort, students are able to easily build 2 level high structures, but anything beyond that is a challenge because marshmallows are actually terrible building material (This is why marshmallows are used. It’s inherently and deceptively challenging because they are too stretchy).
6.       To build beyond two levels, first the buildings must be reinforced in the bottom with two toothpicks vertically used in the each corner of the ground floor cube. This applies to both cube designs.
7.       There are infinite ways to build higher than two levels. Try different ways and see what you and your students/kids can come up with.

The key concepts I talk about in class are:
1.       Fatigue Failure – there are some great definitions on the web, but I tell my students that it’s a fancy engineer’s way of saying it just got tired after repeated loading and unloading of weight (in this case, it’s the weight of the building itself).
2.       Dissipation of forces – again, there are some great definitions on the web, but I tell my students it’s spreading out the weight or the burden. If one person is holding up something very heavy, it’s much easier if two or three people share the burden of holding up the same weight (the example of two toothpicks in the same corner instead of just one).

Here are some other neat structures you can build with your kids/students.

Experiment and have fun!

Saturday, November 10, 2012

Why I started

Hello there. A little introduction before I start.

My background is in mechanical engineering, but never really practiced it in reality (as in design or mechanical aspects of it). After graduating from Cal, I went to work for Bechtel as a project controls engineer (project management, heavy emphasis on cost and schedule), then I worked mostly as a project manager and product marketing manager when I made my way into the semiconductor industry.

After almost 7 years combined of being a stay-at-home mom, along with a writer (Waiting for Appa, and others), and a volunteer science teacher at my children's elementary school, I finally decided to blog about it this year. According to my calculations, I've conducted over 250+ projects in the last six years, covering the grades K to 5th. The projects range from marshmallow buildings and earthquakes to linguistics and language patterns.

I've noticed that there are a lot of science websites and blogs online, and I'll share what I thought were some of the best ones later on. What's special about my projects is that the supplies are very inexpensive and readily available almost anywhere around the world. My goal is to make science and math fun for every child, but more importantly, I want to nurture their natural sense of curiousity and encourage their love of learning.

My children are very curious, and even as toddlers, I used to give them things, household stuff, to keep them occupied while I was busy with making dinner, etc. During this time, I was often surprised at how much I had underestimated what they could accomplish and understand when I explained what had happened. Then when my first child started 1st grade, I decide to actively conduct science projects in his class every week (in kindergarten, I volunteered to help with art projects and read Korean fairy tales to the students). Now, it wasn't "science" every week. I've taught the students Korean alphabet and some key words, along with how to write their names and few basic phrases. Other times, it was more craft orientated project, constructing an origami box. Over the years, I've amassed a group of core projects which could be tweaked infinitely, and these are the projects which I take back to classes each year.

I usually start the years with a civil engineering project titled Magnificent Marshmallow Marvels. I'll write about this project in my next blog (which I hope to have it by next week).

Have a great week!