Now move the bottle back and forth, side to side and you will notice you have a wave in the bottle!
The waves will be bigger at one end of the bottle and smaller at the other.
The reason is because Your bottle wave is like an ocean wave.
Water moves up and down and doesn’t go forward as the wave goes through the water.
The friction between water and wind makes a wave.
Longer waves travel faster than shorter ones and go further before friction makes them disappear.
Our planet waves also happen when our earth spins on its axis and water is pulled by gravity across the geological formations of the ocean floor.