Assignment 3

Please watch https://www.youtube.com/watch?v=7n3RWAIlzAI , especially the story about the great astronomical achievement of Isaac Newton, after 35:30. Newton was able to prove mathematically that Kepler's laws (emirical laws of nature) follow (in fact, are equivalent to) the universal gravitational force which falls with the quare of the distance between any two bodies.

(i) Why was that a breakthrough?

The motion of objects in the night sky was an intriguing and dynamic topic in the ancient era. It had been strongly debated by various scientists, some who claimed the objects to be revolving around the Earth at the centre of the then perceivable universe, while others like Copernicus, Kepler believed that the Sun was at the centre and that the Earth and other planets revolved around the Sun. The hitch in both of those views was that, there were no conclusive theoretical proof as to why one of the was true over the other. Though both were of different complexity, they could explain the motion about equally well by various men like Aristotle, Ptolemy, Copernicus, Kepler, Galileo, etc. Finally, Newton's work of Philosophiae Naturalis Principia Mathematica was published on July 5, 1687 [1] contained the universal law of gravity which could elegantly explain the motion of not only planets around the Sun, but also that of the satellites around planets and the objects on Earth. This theory basically explained the precise empirical results of elliptical motion of planetary objects in the sky that Kepler had formulated using Tycho Brahe's precise data. This was a huge breakthrough for Science because it revolutionised the beliefs and way of the reasoning, research starting the modern era of scientific works. 

[2] Figure 1: Title page of Newton's Philosophiae Naturalis Principia Mathematica

(ii) Study, using any materials you like, the history of that discovery. It started much earlier than the date of Halley's visit to Cambridge, shown in the documentary. There are parts not covered by the documentary, like the role of Newton's arch-enemy Robert Hooke. In the opinion of some historians, especially recently, that Hooke made important contributions, but dispised by Newton was never properly acknowledged. Describe your findings about Newton, Hooke, Halley and Wren's discussions about astronomy, who they were, where the discussions took place, and so forth.

Edmond Halley was born in 8 November 1656 in London, England [3], who's name is designated to Halley's comet was a great observer who made important measurements such as occultation of Mars by the moon and of course predicted the orbits of comets. He was very curious in the problem of an "invisible" attraction between planets in the night sky. He suggested that this force decreased proportionally to the inverse square of the distance between the Sun and the planets and also suggested that they should follow elliptical orbits, like Kepler had described! But he did not have a theoretical explanation to back his suggestions. At that time, Robert Hooke, well known for his Hooke's law describing oscillatory motions of objects attached to certain springs was born in 28 July 1635 in Freshwater, Isle of Wight, England [4]  had assured Halley that his suggestions could explain all the celestial motions [5]. This was backed also by Christopher Wren, the architect of the new St. Paul's Cathedral in London. 

[6] Figure 2: Edmond Halley enquiring Newton about a theory to explain the celestial motion

Halley, on a quest to find a theoretical explanation to the observed celestial motions when Robert Hooke had told Halley that he already had formulated that theory and that he would keep it a secret until a suitable time.  Halley, however was not satisfied with Hooke's responses and so decided to seek Newton who was at Trinity college [5] to find out if he had any idea of a theory that could explain the celestial motions. This was a revolutionary moment in the birth of classical mechanics and modern scientific era.  

Hooke was a competitor to Newton, they feud over various scientific matters. This could have been an important reason in what could have stimulated Newton to finally share his great work on the law of universal gravitation when Halley visited him 

(iii) Briefly, what was the issue between Newton and Gottfried Wilhelm Leibniz? How did this become the reason for a rift between the British and Continental science? (You may want to watch one of the youtube documentaries about Leibniz.) What are your thoughts about the issue of importance of the first realization (first discovery) vs. full formulation of a theory? If two persons claim those two contributions, who's more worthy of paraise and a place in history of science. In another situation: who's the real discoverer: a person who first made a discovery but kept it secret, or the one who made it later and announced it first?

The idea of "infinitely small" was introduced in calculus from which a new branch of mathematics was born which would later be the basis for so many practical applications. Grottfried Wilhelm Leibniz was a German mathematician [7] born in 14 November 1716. The interesting controversy with the invention of calculus is still alive among historians, some of who claim that it was Leibniz who founded calculus before Newton, reasoning with Leibniz's notations that he started working on calculus earlier than Newton. Some other historians believe it was Newton who formulated calculus. In their times, this rift between Newton's and Leibniz's claim over calculus broke into full force in 1711[8].  This was a fuel to the political fire between the Mediterranean continent and the British. 

In terms of the importance of first discovery vs full formulation of a theory, I feel that the person who formulated the full theory should deserve more importance as it would contain a lot more physics and concepts. Also, in the view of science, the importance lies with concepts and the formulation of the theory and hence the formulation of theory should be more worthy of praise. 

[9] Figure 3: A picture of Newton (on the left) and Leibniz (on the right)

In terms of the real discoverer, I feel that the person who made the discovery should deserve more importance though they kept it secret because it is the thinking that matters and just because someone happened to share it before them shouldn't really be of much importance from a science point of view.

References:

[1] http://en.wikipedia.org/wiki/Newton%27s_law_of_universal_gravitation

[2] http://www.library.usyd.edu.au/libraries/rare/modernity/images/newton5-1.jpg

[3] http://www.space.com/24682-edmond-halley-biography.html

[4] http://en.wikipedia.org/wiki/Robert_Hooke

[5] http://www.pbs.org/wgbh/nova/newton/principia.html

[6] http://www.lookandlearn.com/blog/1564/birth-of-edmond-halley/

[7] http://en.wikipedia.org/wiki/Gottfried_Wilhelm_Leibniz

[8] http://en.wikipedia.org/wiki/Leibniz%E2%80%93Newton_calculus_controversy

[9] http://deskarati.com/2011/03/10/leibniz-and-newton-calculus-controversy/