Apples falling from the tree are common sight in apple growing regions. Some times a very common sight or event spark great ideas in a great mind. It is said that falling apple sparked the idea in the mind of Sir Isaac Newton that the earth attracts all the objects towards its centre. Newton generalized this idea and stated that not only the earth, but any object in the universe attracts any other two objects is called the force of gravitation or gravitational force which in fact give rise to the effect of gravity on earth.
Due to the gravity on earth, we can easily recognize as what is up and what is down. It is interesting that the plants also recognize the presence of gravity. When a farmer sows seeds in the soil, he does not take any special care to the place the seed in a specific direction and in the specific orientation. In whatever way the seed is placed, the main roots finally goes in the downwards direction and the stem in the upwards direction. How does the seed buried in the soil know which is the upward direction and which is downward direction? It does so because gravity affects the growth of the plant’s different parts. Even if a young plant bends after a storm, it does not keep growing in that direction. Eventually it bends and grows vertically. This is one of the example of effect of gravity on earth. There are some effects of gravity on earth. If the gravity is not present we cannot stay on the earth. Any object which is throwing upwards never comes on the earth. Rain does not fall on the earth, because the drops of water during rainfall exerts the gravitational force due to the gravity of the earth.
Here we conclude that in the absence of the gravity on earth, the survival of life on the earth is not possible. Even we cannot walk, run on the earth without gravity. If the gravity on earth disappears then we cannot think any soft drink and even we cannot eat any food item because due to gravity the food items goes downwards in our stomach.