Egghead Science: The Strong and the Weak of It
When it comes to structural engineering, there is a lot to be learned from the shape of the mighty egg. At the same time, sitting on an egg doesn't always work out so well. From eggs to domes to bridges, there is family science at hand perfect for spring break exploration for young builders and engineers! Be prepared to be slimed by some breakages and dazzled by some shows of surprising strength!There are chickens at my son's elementary school, and it is great to see kids running to the coop in the afternoons to interact with the chickens, to help with coop duties, and, to check for eggs. With only a few chickens and a few eggs relative to the number of interested chicken watchers, there are some basic school coop rules about gathering the eggs. But when you are the only student around in the afternoon, and you find an egg, you may find that you just got lucky. My student stopped by the coop one afternoon last week and was excited to find an egg that had not yet been collected. It was, indeed, fresh from the chicken, and he insisted I feel how warm it was to the touch—warm and smooth and perfectly ovoid in shape.
Unfortunately, in addition to being warm and smooth, eggs are also fragile. Elementary school students know this. Most of them have had plenty of experience cracking eggs in school and home kitchen science and baking projects. But despite what they "know"—that eggs crack—sometimes maybe there is an irrepressible need to goof around with an egg. Maybe that need is especially strong when you've just gathered it, warm and smooth. But when you joke around and pretend to sit on the egg as the chicken must have, chances are good you will end up with a pile of gelatinous goo, even if you are not really trying to sit with all of your weight, even if, really, you are just being silly.
That is what happened to us, and egghead excitement quickly turned to nine-year-old despair. A broken egg isn't nearly as much fun, and the chickens didn't care that his egg had cracked. The chicken was done for the day. There wasn't another egg ready and waiting to be found. These are sometimes hard lessons that go along with chicken care, egg gathering, and any kind of hands-on science.
The incident with the egg was a reminder to us that eggs are fragile. We crack them to break them open when we want to cook or eat them. While looking at science project ideas in preparation for this week's focus on Easter and family and class egg boiling and dyeing activities, I ran across the "Fallen Arches: The Surprising Strength of Eggshells" materials science Project Idea.
As the title suggests, the project is all about the strength of the egg shape or, more specifically, of half an egg—an arch. This is a fun hands-on engineering experiment for even the youngest of student scientists. With three half eggs, sitting point-side up and arranged in an evenly-distributed triangle, how much weight will they hold before caving? You and your young scientists might be surprised!
If you keep a few eggs aside when you boil others for dyeing, you can engage your students with a great hands-on science activity that easily feeds into other questions and experiments about structures and building designs. As you and your students talk about arches as a structural element, you may find that there are examples in your neighborhood that can add even more relevance to your exploration and your student's understanding of arches in the real world. A small stone bridge walkway that crosses a favorite duck pond of ours is built using arch shapes. An arch bridge is a classic bridge design, in fact. (To extend your discussion, look up keystones!)
From Eggs to Engineering
The following hands-on engineering projects can easily be turned into fun family science activities, great for spring break, summer vacation, or a rainy day. Many of these projects involve some combination of physics, structural engineering, materials science, and math, which gives them great range and versatility. A lot depends on what questions you and your kids want to ask and explore. Why, after all, are the half eggshells arranged in a triangle in the "Fallen Arches" project?
That you can spend an afternoon assembling straws or rolls of newspaper and wind up with an awesome three-dimensional object worthy of display gives these projects added pizzazz for families that love DIY projects and the art that evolves from hands-on exploration. On the flip side, there are structural engineering projects where the goal is to build them so that you can break them. For some kids and families, that is exactly the ticket for thrilling science!
Check the following Project Ideas for more suggestions for families that love to build:
- "Dome Sweet Dome": build a geodesic dome using struts made from rolled-up newspaper. (You can do a similar activity with straws.)
- "Building the Tallest Tower": great for the younger crowd as long as no one gets upset when the tower tumbles!
- "The Effect of Bridge Design on Weight Bearing Capacity": test two different bridge designs, a Warren truss bridge from Popsicle sticks and a Howe truss bridge made from straws. This is a build and break project, so be prepared!
- "Can a Toilet Paper Tube Support Your Weight? *": how big would a tube need to be for you to stand on it without it caving in? How does the answer change if you fill the tube with various materials?
- "Newspaper Tower *": how tall of a tower can you build with two sheets of paper—and nothing else? What shape will it take to reach the greatest height and to maximize the paper and to make it stand?
- "Paper Bridge for Pennies *": a bridge made out of one sheet of paper, a few paper clips, and the challenge to have it support 100 pennies? Let your engineers loose and see what creative solutions they devise!
Cracking Family Science
In the end, eggs do break easily when force is applied from a certain direction. But held or positioned differently, an egg can withstand more pressure than you might expect. Put eggs—and other building designs—to the test with your kids, and let us know what you discover and what fun you have doing science together!