Did you ever read in the newspaper about houses on the coastlines (of oceans) breaking up and sliding into the sea? How could that happen? Why on earth would anyone build a house where the land is so frail? Let's look into that.

Obtain a 10 by 15 inch baking pan about 5 inches deep. Mix some soil with water to make mud. Beginning at one end, fill about one-third of the pan with mud to a height of 4 inches.

When the mud dries, place a 2 inch layer of sand in the rest of the pan, and add enough water to submerge the sand.

Place a board in the pan at the sandy end, and move it back and forth to make waves. The model represents the ocean battering a shoreline. Observe the waves as they splash against the land mass.

Note how a beach gradually forms, how the particles are tumbled about by the waves, how the land mass is eroded, and how the eroded portions of land are distributed. It is important to realize that over time, even rock is eroded by the wave action (after all, sand is really tiny pieces of rock).

Now you can see how houses on the shorelines break and slide into the sea. We still can't see why people take chances on nature, and build houses where they can easily be destroyed by the sea. I guess, perhaps, for the same reason that municipalities build nuclear energy plants on fault lines, where they are subject to earthquake!