Inthe early years specifically the 1600’s, mathematicians and acouple of astronomers tried to perform an analysis on knownastronomical data. That was in pursuit of developing a law that wouldin the best way describe the motion of planets around the sun.Kepler’s three laws single-handedly emerge as the explanations tothe planetary motion. The three laws include the law of ellipse, thelaw of harmonies and the law of equal areas. The laws provide aconcise description on the motion and paths of the planets whenmoving about the sun. There exists no logical explanation on why suchpath exists or what lead to the formation or alignment of such. Thequestion, therefore, arises as to what causes the planets to moveabout the sun as they do.
Kepler,who was a great astronomer of his time, is also not in a position totell whether there is some of the interaction between the planets andthe sun. The interaction would have to the cause of the change.According to Kepler, the planets are in a way magnetically driven torevolve around the sun following their elliptical trajectories.However, there is no interaction between the planets themselves. Onescientist however does not take in the ideologies of Kepler.
IsaacNewton is troubled by the lack of explanation on the movement of theplanets along the orbits. Newton, therefore, poses an argument thatmust be other outside factors in existence that play a part in theelliptical motion of the planets. What troubles him most is themovement of the moon around the sun. He goes further to offer asuggestion that a power governs the heavens that control the moonaround the earth and the planets in an elliptical path. Newton namesthe force as the component force. The actions are said to bedepartures from the initial paths of objects. Hence, the movementsrequire a cause in the form of an unbalanced force.
Thecircular motion needs an energy that is the centripetal force. Newtonwas still bothered by the nature of the force, its origin and itscause. As time elapsed, a breakthrough came to him at the age of 24in the form of an apple. He did not particularly write about thebreakthrough, and it is the usual claim that the gravity notion isthe prime cause of all heavenly motions. Newton gets struck by anapple on his head when under a tree.
Thetheory of the apple is perceived by some to be a myth while otherssee it as a reality. The arguments notwithstanding, the fact remainsNewton relates the movement of heavenly bodies to earthly movements.That is the primary basis for the notion of universal gravitation.Newton adopts an example of mountain thought experience. Hisreasoning is that supposed a cannon ball is fired horizontally at ahigher speed from the top of a mountain.That is done within a particular region, devoid of airresistance, then in the absence of gravity will be to fly in astraight line which he calls the tangential path. In the presence ofgravity, the cannon ball move will drop in a straight line path andeventually land on earth.
Themovement of the cannon ball is a simulation of the orbitingexperienced by heavenly bodies. It simulates the orbiting of the moonaround the earth. If the movement of the moon can be compared to theorbiting cannon ball, it can also be in juxtaposition back to backwith the falling apple theory. It is a safe assumption that the forcecausing objects on earth to fall to the ground is the same force thatcauses heavenly bodies to move along their paths. The laws ofmechanics governing the movements of objects on earth, also governsthe motion of objects in the heavens.
Newton’swoes are not over just yet since he faced with the dilemma ofproviding reasonable and logical evidence on the extension of thegravitational force from the heavens to the earth. He shows that theeffect of the gravitational pull is dilute with distance. He is alsoable to prove that the rate gravity pulling the objects towards thecenter of the earth is at anacceleration rate of 9.8 m/s2.Moon`s acceleration towards the earth by gravity force is 0.00272m/s2. That shows that there must be an explanation as towhy the rate of the moon is smaller than that of other objects. Acalculationwas further in order.
gmoon/ g apple =0.00272m/s2 /9.8m/s2 = 1/3600
A riddle is brought forth pertaining to what mathematical reality isthere to the force of gravity causing it to be inversely dependentupon the distance between objects. The puzzle is solved by comparingthe distance from the apple to the ground with the distance from themoon to the core of the earth. The moon in its path is approximately60 times further from the earth’s center as compared to the apple.That makes the above mathematical explanation withstand the test oftime. Gravitational pull between the earth and all objectsisinversely proportional to the square of the distance that separatesthe object from the surface.
Afterexploring the theoretical and numerical avenues proves the circularmotion and gravitational pull by Newton, an argument is in order. Theargument is that altering separation distances will result in analteration in the gravitational force between objects. The twoquantities seem to be inversely proportional thus an increase in onewill lead to a decrease in the other and vise versa. Newton’stheories are, therefore, fully supported.
"Johannes Kepler: The Laws of Planetary Motion." JohannesKepler: The Laws of Planetary Motion. Web. 7 Nov. 2014.