Motion has been studied for centuries by many great minds. Aristotle (284 – 322 B.C.) for example, believed that a moving object needs a continuous application of force to keep it... Motion has been studied for centuries by many great minds. Aristotle (284 – 322 B.C.) for example, believed that a moving object needs a continuous application of force to keep it moving. To him, an object is naturally at rest. He believed that the greater the force on the object, the greater is its speed. He introduced the idea of impetus that keeps a body in motion. John Philoponus (550 A.D.) conceptualized the idea of surrounding force similar to inertia found in Galileo’s idea and Newton’s First Law of Motion. He first introduced 'Theory of Impetus', a concept similar to force. According to the theory, when impetus decreases, the speed of the object also decreases. When that impetus is removed, the object stops moving. Jean Buridan (1300 -1358) also saw impetus as the cause of movement. He further developed the 'Theory of Impetus' introduced by Philoponus. According to him, motion is possible through a 'mover' that keeps the object moving with power proportional to the speed and mass of the object. When the mover is removed, the object stops moving. He later named impetus as force. Galileo Galilei (1564 – 1642), on the other hand, disagreed to Aristotle. He claimed that even without a continuous application of force, an object can continue to move with constant speed in a straight line provided there are no outside forces acting on it. Finally, Sir Isaac Newton (1643 – 1727) used Galileo’s ideas and eventually formulated the three laws of motion. Read more