Universal Gravitation - Discovery Disputes

Sir Issac Newton was a mathematician and physicist who studied at Cambridge University. He was and still is the most intelligent being of our time for he discovered the basis of all knowledge today. Not only was he the first to use calculus, he also published a book based on light and optics. However, his most important discovery was based on gravity, a force that attracts a body towards any other physical body having mass.

Philosophiae Naturalis Prinipia Mathematicia,
Mathematical Principles of Natural Philosophy

     Of his numerous phenomenal achievements, Newton's astronomical achievement lead to answers of questions that have been asked for years. Issac Newton mathematically proved that empirical laws of nature follow and are equivalent to the universal gravitational force. When questioned about planetary orbits Newton showed mathematical proof using calculus that the planets did not orbit the sun in perfect circles, but rather in elliptical orbits. He also stated that the planet obeys the inverse square law of gravity and so must travel in an elliptical orbit. The inverse square law says that if a planet is twice as far from the sun, the gravitational attraction is four times weaker.
After publishing his book "Mathematical Principles of Natural Philosophy", people realized Newton was discussing a new framework for understanding the universe. He built on many scientists work prior to him such as Galileo. Galileo suggested that objects on

Thought Experiment - Canon ball shot
from top of mountain and demonstrates
elliptical orbits.

Earth and celestial objects' motion were completely different and so required different methods. However, Newton disagreed and stated that the same laws governed motion on Earth and the heavens. This led him to create three laws of motion that would be true anywhere (on Earth and outer space). These laws have strongly impacted our understanding of objects and their motion that they are widely used today and without them many discoveries may have not been made. However, in order to explain how the planets orbited around the sun, Newton used the thought experiment. This experiment involved him imagining a canon ball being fired both strongly and weakly. He concluded that since all objects move in a linear motion and that gravitational forces have an effect, if the canon ball is fired strong enough it will continue in an orbit just like that of the moon. This breakthrough led to the idea that gravitational forces are a result the elliptical orbits and the motion of the planets.

Inverse Square Law 

     Robert Hooke is widely known for being Newton's arch enemy. This is because Hooke believed that he had a huge role in Newton's discovery of gravitational forces and the planets orbits around the sun, and feels as if he did not receive the credit he deserved. By 1670 Hooke believed that the Sun and planets were attracted to each other an

d the attraction increased as the two got closer. He also believed that the inverse square law would be linked with the celestial bodies and gravitational attraction. He was also the first scientists to really argue that gravity is a universal force. Edmond Halley and Sir Christopher Wren were also scientists who concluded that the inverse square law determined the attraction between two celestial bodies. However, no one had mathematical evidence to explain the inverse square law. Determined to find a way to figure out the mathematical evidence Wren, Halley and Hooke met at a coffee shop in London. Wren explained that he would offer a reward to whomever could find this mathematical evidence within the next 2 months. Hooke said he had mathematical evidence but could not find it and so Halley took it upon himself to find the evidence. He then went to Newton who appeared with the evidence a few months later. After publishing his work, Newton did not credit Hooke for having any insight on the inverse law and so there was a huge dispute. However, Newton believed that Hooke`s work was almost negligible and did not further his work as much as Hooke believed it did.

     Newton stated that he developed the theory of calculus in the early 17th century but decided not to publish it until 1693. Leibniz on the other hand was more than happy to publish his work in 1684. So the problem here was that both scientists claimed to have independently arrived at the theory of calculus, and so it was a dilemma to decide who to credit. Eventually the Royal Society gave credit to Newton as first discovery and Leibniz as first publication. However, later on due to a very biased outlook, the Royal Society accused Leibniz of plagiarism. This dispute between the two scientists eventually brought a rift between British and Continental science because Newton was English whereas Leibniz was from German, resulting in two different sides for the public to take.
 I personally believe that the person who published the theory first should be credited. This is because anyone can state that they developed a theory without publication - publication is the only evidence that shows that if someone has actually developed an original idea.

References
https://www.newton.ac.uk/about/isaac-newton/life
http://www.pbs.org/wgbh/nova/newton/principia.html
http://www.uiowa.edu/~c22m025c/history.html

All pictures are from public domain.