Tough Eggs

We tend to think of eggs, rather correctly, as fragile things. Indeed, contests for engineering have kids build things designed to protect eggs from breaking after a sizable fall (click here for an example page - or google "egg drop contest" for a bunch of entries.) Nonetheless, today we show that eggs are not that fragile due to their "architecture".

We were able to balance several Milwaukee telephone books on four (half) egg shells without breaking them. What this shows is that the arch (naturally part of the egg) is an amazine way to distribute force, and that's why it's so useful in things like bridges or buildings.

What we did for our experiment was to take the following steps.

1. We cut a hole in the smaller end of an egg to remove the insides.

2. We washed out the insides.

3. We put a piece of scotch tape around the middle of the egg.

4. We cut the egg along the tape so we had half an egg.

• we did this with a scissors and it works
• for the eggs we showed on TV we used an exacto-knife and that worked better, but it's more dangerous so for kids to do this you probably need to use a scissor (and still BE CAREFUL).

5. We arranged four egg halves in a rectangle on the table top.

6. We started piling up telephone books until we heard an egg crack.

Science experiments like this are always fun for kids because they show it's possible to do something that doesn't seem possible. The key to making it science (and not magic) is to talk about the strength of an arch...and still have fun doing the experiment with tough eggs!

Links

Meeko Lab Page - where we discovered you can balance phone books on eggs.