Montshire Minute: Eggs

Originally aired during the week of November 29, 1999

Monday

Almost every animal on Earth comes from an egg. Eggs come in all shapes and sizes, and most of them you can't find in the supermarket. The ostrich egg is the size of a grapefruit and weighs about three pounds. The human egg is only about 100 microns in diameter. Like birds, most insects, fish, amphibians and reptiles lay eggs outside the mother's body, and have outer shells made of different materials. All these egg coverings are basically designed to protect the embryo and the many fluids it needs for nourishment. The shell of a chicken egg, which seems thin and fragile is a pretty remarkable thing. It needs to be thin enough so the chick can break its way out during hatching, but thick enough to keep the inner fluids from leaking out. The shell is also covered with thousands of tiny pores which lets oxygen pass inside.

Tuesday

Eggs are easy to break, right? I mean the checkout person at the supermarket always puts the eggs on top of your other groceries. Each dozen is carefully packaged with the special cardboard box to prevent breaking. And you know what happens when you accidentally drop a raw egg on the kitchen floor. A big mess. In some situations, egg shells really are very delicate and "breakable." But in other ways, the shell is a pretty strong structure. For instance have you ever tried to break an egg by squeezing it in your hand, applying equal pressure on all sides of the egg? Go on try. I dare yaí. It's harder than it sounds! But hey, sometimes you gotta break a few eggs to learn more about science, right? Nature has come up with the egg shape to be light and strong. The egg must be durable enough to withstand the impact of falling on the ground when the chicken lays it.

Wednesday

When you crack an egg on the edge of a bowl, you crack it on its side right? It's harder to crack the egg on one of its ends. Look closely at both ends of an egg and you'll see arches of slightly different shapes. Engineers have learned that these arches can be the basis of really strong structures. You can see egg-like arches in buildings and bridges. The arch at each end of an egg can support a surprising amount of weight. You can test this idea by using some clay to stand a raw egg on its end. (Be surer the narrower end is pointing up). Make two piles of pennies that are the same height as the egg. Arrange the egg and the two piles so that they make a triangle, and carefully place a book over the egg and the coin piles. Don't be shy, start with that big hardcover book, instead of a paperback. Keep piling on the books - come on, keep 'em coming. How many books you can add before the egg breaks?

Thursday

This week we've been looking at the egg-straordinary structure of the eggshell. We're discovering the shell is not necessarily as fragile as it seems. It is made mostly of calcium carbonate, pretty solid stuff. And the rough dome shape evident in eggs can be a very solid weight bearing structure. The domed igloo, for instance, can withstand the weight of Polar bear trying to get a better view of the Arctic landscape. Still, eggs are not indestructible. Drop a raw chicken egg onto a hard floor from a height of 18 feet, and the egg would need some special survival strategies. That's where you come in. On Saturday, April 8, 2006, we'll be hosting our annual egg drop challenge, where you are invited to build a "container" that will successfully cushion a raw egg from impact after being dropped off our second story balcony. Sound egg-citing? Call the Museum for more information.

Friday

How do you like your eggs? Boiled? Scrambled? Poached? How about: airborne? On Saturday, April 8, 2006, we'll be hosting our annual egg drop challenge, where you are invited to build a "container" that will successfully cushion a raw egg from impact after being dropped off our second story balcony. The word "raw" is really key here. How can you tell if an egg is hard boiled or raw? Without cracking them I mean? Here's a little trick to help you tell the difference. Boil an egg and put it on a plate with an uncooked one. Now, spin each of the eggs at about the same speed. The egg that spins the longest is your hard boiled egg! So when you grab an egg out of your refrigerator for Montshire's Egg Drop challenge on Saturday, you'll want to be sure you've got the uncooked one. Otherwise, you'll really have egg on your face.