(i) the Earth is spinnig around its axis every day, while the immense distant world of stars is motionless
Nicolaus Copernicus was one of the greatest astronomer of his historic period. He had given quite a lot of proofs correcting the beliefs people had in his period. Most of these proofs have been recorded on his book, De Revolutionibus. This short paper summaries the proofs of some of the theories which helped the people get the correct perspective of the solar system.
One of the proof he produced was for the Earth spinning around its axis everyday. Most of the ancient astronomers believed in the Earth being stationary and at the centre of the known "universe". Ptolemy argued that the things that were not attached to the Earth would all appear to move to the west. This was the commonly accepted belief. But Copernicus responded that all falling bodies that were made of Earth shared a rotational component with the Earth and a radial component velocity towards the centre of the Earth. This is shown in Figure 1. Below is a quote of Copernicus giving a logical reasoning based on the motion of ships floating on an ocean.
[1]"For when a ship is floating calmly along, the sailors see its motion mirrored in everything outside, while on the other hand they suppose that they are stationary, together with everything on board. In the same way, the motion of the earth can unquestionably produce the impression that the entire universe is rotating."
(ii) the Earth is a planet orbiting the Sun once a year like the other planets, so it is not in the center of the universe
(iii) the Sun does not orbit around the Earth, but remains motionless in the center of the planetary system.
Copernicus came up with a unique and very interesting proof of how the difference in the brightness of Mars cannot match the observations if we were in a Geo-centric system and that the observations of the difference in the brightness of Mars can be explained with a Helio-centric system. The Figure 2 shows the Helio-centric model which Copernicus used to explain the observations which is a revolutionary proof for the Helio-centrism of the solar system.
This proof is not only accurate, but also elegant and convincing to say that helio-centrism is perhaps what our solar system is. In the sixth century BC, Pythogoras had suggested this idea of helio-centric solar system and few centuries later, Aristarchus also backed this idea of the Sun being motionless at the centre of our planetary system. [3]
I consider the third proof the most important. This is because, firstly it is beautifully elegant and precise. It is simple to understand and hence easy for scientists to agree with. I also consider it important because it is a revolutionary piece of work which helped in the change of the mindset of people from thinking that Earth was the special body in space and that everything else acted around Earth to the actual reality of Earth being a rocky body revolving around the Sun. I feel it is a point where scientific arguments were encouraged and this work is a perfect example of such a reasoning. It is also an example of the Occam's Razor principle where a theory which is elegant and simple to understand is much better than a theory with complicated arguments. [4]
References:
[1] Nicholas Copernicus, On the Revolutions of the Heavenly Spheres, Johns Hopkins University Press, 1992.
[2] http://www.geocentricity.com/conference/Frank/epicycle_conference_bible_2_final.pdf
Nicolaus Copernicus was one of the greatest astronomer of his historic period. He had given quite a lot of proofs correcting the beliefs people had in his period. Most of these proofs have been recorded on his book, De Revolutionibus. This short paper summaries the proofs of some of the theories which helped the people get the correct perspective of the solar system.
One of the proof he produced was for the Earth spinning around its axis everyday. Most of the ancient astronomers believed in the Earth being stationary and at the centre of the known "universe". Ptolemy argued that the things that were not attached to the Earth would all appear to move to the west. This was the commonly accepted belief. But Copernicus responded that all falling bodies that were made of Earth shared a rotational component with the Earth and a radial component velocity towards the centre of the Earth. This is shown in Figure 1. Below is a quote of Copernicus giving a logical reasoning based on the motion of ships floating on an ocean.
 |
| Figure 1: Rotational and radial component |
[1]"For when a ship is floating calmly along, the sailors see its motion mirrored in everything outside, while on the other hand they suppose that they are stationary, together with everything on board. In the same way, the motion of the earth can unquestionably produce the impression that the entire universe is rotating."
(ii) the Earth is a planet orbiting the Sun once a year like the other planets, so it is not in the center of the universe
Similar to the belief about the rotationless Earth, Ptolemy argued that since only half of the stars on the sky at any given time, the Earth had to be in the centre. But Copernicus debated that it is because of the distance between the centre of our solar system and the Earth is small that it doesn't produce any noticeable effects. Copernicus also opened up the possibilities of Earth being just another normal rocky body in our solar system which was a huge shift in the position of Earth in our Universe that people had in mind.
[2]Copernicus argued that the Earth moved as a whole in a circular orbit around the centre of the solar system because of the observed retrograde motion of planets like Mars which could not be so accurately and elegantly explained by other models. He also used the reasoning that parallax could not be applied to all observed bodies in our solar system which suggested that perhaps Earth is not the centre of the solar system and that it orbits the Sun 360 degrees in one year (by definition) similar to other planets.
(iii) the Sun does not orbit around the Earth, but remains motionless in the center of the planetary system.
 |
| Figure 2: This is a script of Copernicus portraying the centre Sun solar system |
This proof is not only accurate, but also elegant and convincing to say that helio-centrism is perhaps what our solar system is. In the sixth century BC, Pythogoras had suggested this idea of helio-centric solar system and few centuries later, Aristarchus also backed this idea of the Sun being motionless at the centre of our planetary system. [3]
I consider the third proof the most important. This is because, firstly it is beautifully elegant and precise. It is simple to understand and hence easy for scientists to agree with. I also consider it important because it is a revolutionary piece of work which helped in the change of the mindset of people from thinking that Earth was the special body in space and that everything else acted around Earth to the actual reality of Earth being a rocky body revolving around the Sun. I feel it is a point where scientific arguments were encouraged and this work is a perfect example of such a reasoning. It is also an example of the Occam's Razor principle where a theory which is elegant and simple to understand is much better than a theory with complicated arguments. [4]
References:
[1] Nicholas Copernicus, On the Revolutions of the Heavenly Spheres, Johns Hopkins University Press, 1992.
[2] http://www.geocentricity.com/conference/Frank/epicycle_conference_bible_2_final.pdf
[3] Andrew Dickson White, A History of the Warfare of Science with Theology in Christendom, D.Appleton and Company, 1896.
[4] Steven Dutch, 21st Century Geocentrism, Natural and Applied Sciences, University of Wisconsin - Green Bay
*no figure references = plagiarism! Consider this a warning, and make sure to include these on your next posts*
ReplyDeletein-text citations don't come at the beginning of the paragraph, rather where the information has been used (sometimes mid paragraph)
you haven't addressed some of the questions in the assignment