ISAAC NEWTON It was a sunny day. Newton was lying under a tree in the garden of a college in Cambridge. Suddenly,
an apple fell from a tree close to him. Newton stared at the apple. Then, in a flash of inspiration. he thought up the law of Universal Gravitation. This little tale is a romantic way to tell what, in fact, was the product of pure scientific reasoning.
Newton received the main credits for the formulation of the law. We know however. that its basis had started long before he was born. Johannes Kepler. who was a 16th century scientist, had formulated important laws of planetary motion whose principies were essential to the conception of the law of Gravitation.
Kepler''''s laws had only provided a geometric description of planetary motion. but no explanation. It was Newton who gave an explanation through Physics. After he had
observed the orbit of the moon. he noticed the existence of a force that kept the moon in movement around the earth. When he compared the
acceleration of different bodies falling on the surface of the earth, Newton concluded that the acceleration did not depend on the mass of the body. He also concluded that, as this happens on the surface of the earth. it can also happen at any other point of the universe.
Newton''''s final formulation of the law of Gravitation says "every particle attracts every other particle with a force directly proportional to the product of their masses and inversely proportional to the square of the distance between them."
This theory was not his only important contribution. He also gave the world an example of an attitude. He showed that a theory can explain observed facts. It can also propose new observations. This ability to formulate a theory reflects the genius in man.
By Fausto Fabio de Araujo