Walking on Eggshells

Theme: God tenderly cares for us.

Bible Verse: Are not five sparrows sold for two copper coins? And not one of them is forgotten before God. (Luke 12:6)

Materials Needed:

• Several half eggshells

• Masking tape

• Scissors

• Several books

Bible Lesson

Who cares about sparrows? After all, there are billions of these common birds. The answer is that God made them and he also cares for them. Sparrows in Scripture refer to any small bird of the finch family; they are still found throughout Israel. Each sparrow contributes its chirps, beauty, and nonstop activity to our world. Sparrows spend most of their waking hours in search of food. They don’t live long; the record for a sparrow in captivity is ten years. God has given all types of birds instinctive knowledge about nest building, egg care, and feeding their young.

God values his children far above sparrows. In fact, he knows the very number of hairs on our heads (Luke 12:7). Just as God provides for the animal world, so he also provides for us. Christians are not on their own in this world; God watches out for us in many ways that we do not realize.

Science Activity

This activity shows how well the Creator cares for baby birds within their eggshells. Obtain four or five eggshell halves by cracking fresh eggs. Run a strip of masking tape around the broken edges of four egg shells; then trim the edges of the shells smooth and even with scissors. The tape will prevent the shells from cracking; it can be left on or removed after trimming.

Now place the eggshells, all roughly the same height, on a table with the open ends down. These small egg domes provide “legs” for a book that is gently laid upon them. Add additional books to make a stack on the eggshells. Carefully add even more until one of the shells finally collapses. The books should add up to an impressive amount of weight. You might have a strong volunteer pick up the stack of books to demonstrate the effort needed. An eggshell has been shown to support a person who is perfectly balanced on it.

The eggshell provides a strong home for a baby bird. The shell easily withstands the weather and the weight of the sitting mother. The baby emerges by breaking the shell from the inside out. This is a much easier task than breaking an egg from the outside.

Eggshells will support a heavy load.

Science Explanation

The dome structure of an eggshell is one of the strongest shapes possible. The thin shell is made of calcium carbonate, CaCO3, which isn’t very strong in itself. You might crush an extra eggshell to show participants how fragile they are. However, when the book weight is applied to the top of the dome, the force is transferred along the shell surface to the base. This force tends to compress the eggshell and is strongly resisted. The dome shape is often used as a roof in large stadiums and arenas where supporting columns are not practical.

Here are two other ways to show the strength of an eggshell. If you hold a fresh egg in your palm, it is nearly impossible to crush the egg by squeezing the ends together. Make sure to try this over the kitchen sink, and be careful since the edge of an eggshell can cut. You can also safely toss a fresh egg upward as high as possible above a grassy lawn. The strength of the eggshell and the cushion of grass will almost always prevent the egg from breaking when it lands.