Rocket and Raven sit on the end of a wooden dock. A yellow leaf floats on the lake below them.
A breeze sends ripples rolling toward shore. Rocket waits for the leaf to sail away with them.
It does not. The leaf rises, dips, rises again, and stays almost in the same spot.
"The waves are moving," Rocket says. "Why isn't the leaf going with them?"
Raven leans over the edge. "What do you notice about how the leaf moves?"
Nova hovers low. "My hint," she says. "Watch up and down, not forward."
A wave is a regular pattern of motion. You can make waves in water by disturbing the surface.
Most ocean waves are made by wind rubbing across the water.
In deep water, the water mostly goes up and down in place. It does not travel forward with the wave.
So what moves across the lake? Energy! Waves carry energy, not water, from place to place.
Near a beach, things change. There the water does rush forward onto the sand.
| Statement | True or false? |
|---|---|
| Most ocean waves are made by wind. | ? |
| In deep water, the water travels forward with each wave. | ? |
| A wave is a regular pattern of motion. | ? |
Picture a line of people doing a stadium wave. Each person stands up and sits down.
Nobody runs around the stadium, but the wave travels all the way around.
Water waves work in a similar way. The water goes up and down in place.
The energy is what travels across the lake.
| Statement | True or false? |
|---|---|
| A floating leaf moves up and down when a wave passes. | ? |
| Waves carry the whole lake to the shore. | ? |
| A wave is a regular pattern of motion. | ? |
| Waves can make objects move. | ? |
Wonderful wave watching! Tomorrow we learn the names of a wave's parts.