This is a great experiment and totally amazes the children. You will need:
4 eggs
1 egg carton
A sheet of paper (paper towels, wax paper)
A 2 foot stack of hardback books that are about the same size and weight (which is why I used encyclopedias. I am also probably the only person in town who still has encyclopedias!)
Now place the eggs in the second and fifth row of the egg carton with the pointy part of the egg facing down. Place a sheet of paper over the eggs in case of breakage. Now here comes the egg-citing part. Begin to put the books on one at a time. We were able to place nine encyclopedias on top of our four eggs. We stopped because I only brought nine. Silly me!
I found this experiment in Family Fun magazine many years ago. It was submitted to the magazine by the Ann Arbor Hands-On Museum in Ann Arbor, Michigan. Their explanation of why it works:
"The eggs shape-two dome shapes pushed together-makes it resistant to compression (in other words, a force pressing inward). That's why a mother bird can sit on her eggs without breaking them. On the other hand, eggs and other dome shapes are weak in tension, a force pressing outward, so that a baby bird can easily peck its way out when hatching. Of course, an egg is easily broken from the outside if a strong force is applied in one spot." http://www.aahom.org/
We do not give the children this explanation. We want them to see how strong the egg is and how a mother bird can sit on her eggs and they don't break. Have fun!
