When there is mention of Newton’s Law of Gravity the mind flashes back a vague picture of a young English man sitting under an apple tree. That tale has become a most popular science legend. An apple falls and the young man’s mind gets the gravitation idea. It may not have actually happened but we can speculate over some related aspects.
WHAT HAPPENED TO THE APPLE?
If the apple story is systematically analyzed then we must start from the beginning, Newton had seen an apple falling from a branch. Before that it was there on the branch linked to it with twig stalk and bud connection. The apple was in a state of inertia. It then suddenly got freed when the bud connection broke as the gravitational pull down became stronger. The apple got set in motion and headed down towards earth. Thus the apple being on the branch proves Newton’s first inertia principle. Its fall down invokes second principle of Motion. The motional force was imparted by the gravitation and it was also responsible for the velocity or momentum.
Basically Newton imagined that the apple was on the tree at some height before falling down. That was why gravitational force worked on it. We may also speculate that Newton may have found the apple first in the state of inertia instead of it in motional momentum. In this single event Newton’s creative mind may have mulled over several motional factors or states. His mind may have thrown up a series of question marks in succession as :
- Why the apple gained motion to fall on the earth?
- What force made it move downwards?
- Before the fall the apple was motionless on its stalk that was a part of twig, branch and the tree. What force was keeping it there in immobile state? The gravitational or pull down force should have been active even then. Was the force responsible for the immobility of the apple stronger than the pull down force? The pull down force had to be related to the earth which attracted things towards it from heights.
- Newton had realized that the pull down force alias gravity also manifested as the motional force of the falling object. The things fallen on the ground stayed inert which gave him the idea of inertia.
- Why did things fall from height towards earth and not skywards? And at the same time the moon was also at some height but it did not fall, why?
- A falling object was in motion due to the gravitation of the earth and that motional force was greater than the inertia force.
