By lifting and releasing the pendulum, you can see that you are making a wave on the conveyor belt. If you lift the pendulum higher, the wave tops are also higher. If you let the belt go faster, the waves become longer.
Scientists like to describe waves to better understand the world around us. Waves are everywhere. Think of the waves in the sea. Want to impress your friends next time you go to the coast? Don’t say: “Wow, those waves are high!”, say: “Wow, those waves have a great amplitude! This is the word that scientists use, and they don’t say ‘short waves’, they say ‘small wavelength’. Scientists use this information to create a mathematical formula or ‘function’, to know how the wave moves in time.
Do you want to know why the conveyor belt gives off light? Take a look at the “Luminous wall”.
