Two students build a "string phone" by tying a tightly stretched cotton string between two plastic cups.

A theater technician is using colored plastic gels (filters) over a white spotlight to change the color of the stage.

A research ship uses a sonar device to map the ocean floor. The device sends mechanical sound waves down through the water.

A student is investigating how light behaves when it interacts with different objects.

Engineers select materials for construction based on how those materials alter the path of light waves.

A team of students want to build a box that completely silences a ringing alarm clock. They build two identical chambers but line the insides with different materials.