Treebeard's Stumper 14 April 2000

Wet Sand, Dry Sand

We had a fine time at El Capitan beach last week after our long hike and overnight campout. We didn't last long in the cold ocean water, but the sand was warm. Sand and water are interesting materials that we take for granted. Damp sand that's not too wet holds together just right for sand castles or a game of alligator, our Hike Club beach version of Jenga. You can judge how damp the sand is by its color since wet sand is a darker color than dry sand. Water is not sticky or colored, so how can it hold sand together and change its appearance?

This shows the color difference between wet sand and dry sand at El Capitan beach. The tide is rising up over the dry sand. Notice how successive high waves leave layers of color and detritus. That's another stumper!	Alligator is an old surfer game. Make a pile of damp sand and push a stick in the top. Take turns removing as much sand as you dare. Whoever brings the stick down becomes the alligator and has to crawl into the water while everyone else chucks sand at them. This is the original Jenga game!

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