Newton was the first one to suggest that gravity is universal and affects all objects in the universe. That’s why his law of gravity is called the law of universal gravitation . Universal gravitation means that the force that causes an apple to fall from a tree to the ground is the same force that causes the moon to keep moving around Earth. Universal gravitation also means that while Earth exerts a pull on you, you exert a pull on Earth. In fact, there is gravity between you and every mass around you — your desk, your book, your pen. Even tiny molecules of gas are attracted to one another by the force of gravity.
Beth enjoyed everything about hiking  in the forest she especially liked to watch nature. One day she decided stopped to rest near a clearing and was enjoying the view. It was late autumn and she watched as the leaves fell from the trees and drifted to the ground. Before heading home she walked to a near by river to see the small waterfall there. She always found it peaceful to watch the water go over the edge and fall to the river below.
What was gravity pulling on in the forest?