The purpose of this activity is to demonstrate the strength of the arch and to briefly discuss pressure points.
Materials required:
-Eggs
-Ziploc bags
(Get enough for each student plus a couple of extras)
The arch first appeared in architecture several thousands of years ago and can be seen in the early structures built by the Romans, Egyptians, and Greek (among many other civilizations). The reason the arch was and currently is used is due to its natural ability to evenly distribute weight. This is why the arch is often seen in bridges.
Interestingly, the reason a chicken's egg can withstand then weight of the hen until it hatches is due to the egg's arch shape.
Provide each student with a Ziploc bag containing a raw egg. Explain to the students that it is impossible to break the egg with one's bare hands by squeezing the egg in one's fist. The reason for this is due to the force of the of pposing arches on each side if the oval-shaped egg. Note that if a student presses his or her fingers down in one spot that they will create a pressure point and therefore break the egg.
After the students complete this challenge (they will have fun attempting to defeat your claim and you should expect that some of them may cheat by using their fingers) you can allow them to break the egg inside of the bag and "smush it around" as they might like to do so depending on the age group taught.
