Patterns at the Museum Ripple Studio

A Traveling Pattern

At a science museum's Ripple Studio, a class investigates waves in a long, clear water tray. A museum educator moves a paddle at one end. Students watch from behind a dry viewing rail. A small cork floats near a mark halfway along the tray. A ruler beside the cork helps students measure its motion.

Before each test, the educator lets the water become still. The class records this resting water level. The highest part of a wave is its crest. For this investigation, wave height means the distance from the resting level up to a crest. Wave spacing means the distance from one crest to the next crest.

The educator adjusts the paddle to make three wave patterns. The class uses the same tray, water depth, cork, and starting place in each test. Students measure crest height and crest spacing after a steady pattern forms. They also record the distance between the cork's lowest and highest positions during six waves. They repeat each wave test three times and get the same measurements.

For Test D, the paddle stays still for the same amount of time. Students make the same cork measurement. There are no crests to measure in that test. The records below show the class's results. The cork movement column measures up-and-down travel, not distance along the tray.

During Test B, the class also follows one crest as it travels from the paddle toward the far end. After six waves pass, the cork is still close to its starting mark. Later, students make side-view models to compare the repeating shapes. These models show a wave pattern at one moment, rather than a movie of the whole test.