Why Mama Bird Doesn't
Squash Her Eggs
Today's Snack: Use the insides of the eggs from this project for a
Six large eggs | scissors
| bowl to keep egg yolks and whites
Serrated knife |
toothpick | section of paper toweling
Three to four
dictionaries or other thick, heavy books | masking tape
Have you ever
wondered how a mother bird could sit on the eggs in her nest and not crack them
open before the babies even hatch?
The reason she
doesn't have to worry is that eggs are designed to be very, very strong. The
shape of an egg - a dome or an arc - distributes weight all over the surface,
so that there really isn't a weak point that will give way very easily.
If you have an
extra egg besides the six for this activity, hold it in your hand. Try to crush
it. Can't do it, eh? You have to tap an egg against a hard surface to get it to
Do you think
if you piled several heavy books on top of some eggshells, they'd crack? Oh,
yeah? Well, let's try it.
a "hypothesis" - pronounced "hi POTH uh siss" -- an educated guess - on whether
these shells will break after one, two or three heavy books are piled on them.
See if you're right!
out the contents of the six eggs into a bowl so that you can make an omelet.
All you want is the shell. You going to break it open on just one end.
serrated knife - pronounced "SARE ate ed" -- one with sharp little points all
along the edge -- carefully cut about a dime-size hole off one end of each egg.
Shake the yolk and the egg white into a bowl and set it aside. You may have to
stick a toothpick in there to break the yolk to get it out.
shells with warm, soapy water and let them dry. Wash your hands after handling
eggs are completely dry, apply a small piece of masking tape over the hole to
cover it. That will be the bottom of the egg. It should sit pretty still. Try
to have your six eggs rest as flat to the surface of the table or desk as you
eggshells in a square - three rows of 2 - on a piece of paper toweling. Put one
dictionary on top. Does it break the eggs? Continue with a second and third big
book. Keep going until and unless your eggshells break.
observe anything interesting during this experiment?
Why do you
think eggs are shaped this way, in nature?
think of applications for this knowledge in the real world?
have fun? That's eggs-actly the point!