Sir Isaac Newton: The Aristotelian Theory Of Motion

History of Classical Gravitation Theory
Galileo studied motion especially that of freely falling bodies. He saw a problem with the Aristotelian theory of motion because it required a stationary earth so he developed his own theory of motion. He is probably best known for a story in which he dropped two different size balls from the Leaning Tower of Pisa at the same time. The two balls hit the ground at almost the same time which led him to formulate the law of freely falling bodies. There is no evidence that he actually conducted this experiment, but he was the first scientist to use the results from experiments for evidence for a scientific theory. He also experimented with pendulums and formulated the law of the pendulum. According to his

Now let’s look at the Newtonian version of this, which not only has inertial masses, mi, but also gravitational masses, mg. Since the gravitational force on an object is proportional to its mg, and the acceleration is given by F/mi, the acceleration would be proportional to mg/mi. Unless every object has the same mg/mi then gravity will cause nearby objects to accelerate differently. That's completely different from the effects of changing coordinate systems. When Einstein wrote his general theory of relativity in 1915, he found a new way to describe gravity. It was not a force, as Sir Isaac Newton had supposed, but a consequence of the distortion of space and time, conceived together in his theory as 'space-time'. Any object distorts the fabric of space-time and the bigger it is, the greater the effect. The Schwarzschild radius is the radius of the event horizon surrounding a non-rotating black hole. Any object with a physical radius smaller than its Schwarzschild radius will be a black hole. This quantity was first derived by Karl Schwarzschild in 1916 as Rs= 2GM/c2(squared). A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because