Showing posts with label Kepler. Show all posts
Showing posts with label Kepler. Show all posts

Friday, 5 October 2012

Seminar Paper – The Rise of Science

The Rise of Science: The rise of science, otherwise known as the scientific revolution, took place in the early modern period, 17th century, following the Italian Renaissance where development in , physics, mathematics, biology and chemistry transformed views of society and nature. Historically, the rise of science began in Europe towards the end of the 16th century and continued well into the 18th century. Further along in the 18th century we come to what is known universally as the period of Enlightenment – however, the true start date of the scientific revolution are highly debated as people believe that the publications of Copernicus’s “On the Revolutions of the Heavenly Spheres” and then the publication by Vesalius’s “On the Fabric of the Human Body” are what really set the rise of science in motion which were both published in 1543. The creation of science wouldn't have been possible without the profound insight of 4 great men – Copernicus, Kepler, Galileo and Newton.

Copernicus: Copernicus’s book “On the Revolutions of the Heavenly Spheres” paved the way for modern astronomy. This is because his “heliocentric model”, with the Sun at the centre of the universe, demonstrated that the motions of celestial objects can be explained without putting Earth at rest in the centre of the universe. The heliocentric model depicts the earth and planets revolving around a stationary sun at the centre of the solar system. This theory was opposed by Geocentrism, which placed the Earth at the centre of the solar system. However, the idea of the earth and other planets revolving the sun had been the proposed thousands of years ago but received no real support from any of the ancient astronomers. Thanks to Copernicus’s additions to science in the 16th Century, he managed to invent a way to predict this movement through his full mathematical model of the heliocentric system; this really set the groundwork which ultimately leads to the rise of the scientific method.

Despite the profound impact of Copernican theory, there arose many problems – the most prominent of these is the absence of a Stellar Parallax. A Parallax is a difference in the position of an object viewed along two different lines of sight; therefore a stellar parallax is the effect of a difference in sight on distant stars. It is a way to measure on an interstellar scale, and it can be used to determine the distance of Earth to another star, however this only become possible in the 19th century and this was still only in the case of the nearest stars, making it almost impossible to measure accurately, without the help of a telescope.
           
Kepler: Kepler was one of the first important astronomers to adopt Copernicus’s heliocentric theory and he was highly influenced by Pythagorean theory. Kepler was a German mathematician and astronomer, and is named a key figure in the scientific revolution. His most influential work was published eponymously; this was called the laws of planetary motion. In terms of astronomy, Kepler's three laws of planetary motion had a highly profound impact on science and astronomy, with his three scientific laws describing orbital motion, detailing the motion of planets revolving around the sun.

The first of Kepler’s laws was that the planets move in ellipses – it was generally understood by all astronomers that all celestial motions are circular and these are called epicycles. Therefore this means that the orbit of every planet is an ellipsis with the sun at one time or another. The second law details the varying velocity of the planet at different points of its orbit – I believe this explains how much the planets would move around the sun in their orbit and at what speeds. The third law was very important as it detailed and compared the movements of different planets while the first two laws were all about individual planets which had a mathematical formula to work it out – for example Russell states that “if R is the average distance of a planet from the sun and T is the length of its year, then R3 divided by T2 is the same for all the different planets”.

Galileo: Galileo is viewed as the greatest of the founders of modern observational astronomy, the father of modern physics and the father of modern science, he was only matched in credibility possibly by Newton – he very important as an astronomer and maybe even as the founder of dynamics. His work about dynamics allowed him to discover acceleration and this is defined as a change in velocity. Galileo believed that everyone, if they were left alone would continue to move in a straight line with uniform velocity.

Galileo was the first to discover the law of falling bodies, which is tied in closely with acceleration states that when you are free falling, the acceleration is constant, but the effects of wind resistance would hinder you slightly and that regardless of how heavy, tall or small the body is – it will always fall at the same speed; the acceleration would not change because of these aspects; this could only be fully proved with the invention of the air pump in 1654. Before the profound insight of Galileo, it was generally agreed that if something was larger, then it would fall faster solely on that aspect of it being bigger.

Furthermore, he delved into the study of projectiles – it was generally thought that if an object was fired horizontally it would travel like that for a while and then fall vertically; now Galileo detailed that this would not be the case, he stated that the horizontal velocity would remain constant in accordance with the law of inertia but vertical velocity would be added which ties in with the law of falling bodies The law of inertia explained issues that before Galileo, the Copernican system was unable to confront, for example if you are at the top of a tower and dropped a stone it would fall at the foot of the tower not to the east or west, you would think that if the earth is rotating then  during the fall it should move a small amount. This does not happen because the stone would retain the velocity of rotation which at the time of being released is being shared with the rest of the earth’s surface.

Newton: Isaac Newton built upon all the groundwork towards this scientific revolution that had been put in place by the other three great theorists, the work put in by Copernicus, Kepler and Galileo had set the stage for Newton to shine. Newton details in his work the three laws of motion. The first law – if an object experiences no force, then its velocity is always going to be constant – for example if the object is in rest, its velocity will be 0, or if it moves in a straight line with constant speed  then its velocity is going to be above zero. The second law states that the acceleration of a body is similar and directly proportional of the remaining force, called F, acting on the body, is in the direction of the net force and is inversely proportional to the mass of the body. Finally, the third law explains that when a body exerts force on a second body, the second body will exert force at the same time on the first body; this means that the force of the two bodies is equal in magnitude and opposing in direction.

Newton’s most important work is called “The Principia” and this is generally deemed to be one of the most important scientific books ever written. This is stated because it is independently detailed to the specific physical laws the work successfully. Newton is also highly credited and esteemed as he managed to build the first practical reflecting telescope and developed a theory of colour purely by observing that a prism decomposes white light into the many colours that form the visible spectrum. Newton also worked on celestial mechanics, this concerned gravitation and its effect on the orbits of planets. Here he greatly referenced Kepler's three laws of planetary motion. And if that wasn't enough, he went one step further and also formulated a law of cooling and greatly studied the speed of sound.

Francis Bacon: Francis Bacon has been named the creator and pioneer of empiricism. His works established inductive methodologies for scientific inquiry, which is known famously as the scientific method. The scientific method is the idea that you must always start a new theory from scratch - you must protect yourself from ideas from the past that might influence your ideas – which means it has to be original and it is a means of discovering new knowledge and a process of understanding.

Francis Bacon’s most notable work is called the “Novum Organum” which translates to “new instrument” or “New Organon” and this is an allusion to Aristotle’s work called the Organon, which was his treatise on logic and syllogism. Bacon details a new system of logic he believes to be superior to the outdated use of syllogism, he believed that you had to use the simple method of reduction and use inductive reasoning to gain knowledge.

This 'New Organon' had 4 key themes, the first of these being that knowledge is the source of human power, so we must harness and navigate through all knowledge. Secondly, there must be a clear separation of science and religion, as mixing if caused too many problems in the past. Thirdly the idea "new knowledge" must be thought up from scratch - these ideas or general theories must be then tested to see if they can prove them, or more accurately in later years falsify them. And finally science is dynamic - you must always admit to failure when you encounter it as opposed to the archaic way of never admitting defeat or failure, this is the way that you learn.

Sunday, 6 November 2011

Philosophy Lecture - The Clockwork Universe

Key Terms / Ideas: Astronomy - This is the study of the heavens, so don't confuse this with zodiacs and that whole business. Celestial Heavens - This is the idea that anything above the moon is perpetual; it will always be permanent. Aristotelian and Scholastics - people who are heavily influenced by Aristotle. Which can be summed up as Aristotle + Bible = two main books and sources of knowledge. Sub-Lunar - The idea that nothing is constant, this is the world below the moon and so on, eventually concluding that God is constant and that the world below the celestial heavens is 'cursed'.

Aristotelians all tried to find a model of the earth that fits with the ideas of Aristotle: Ptolemy came up with the idea that the Earth is in fact the centre of the universe; He argued that the Moon, Sun, Planets and Stars all revolve and will never change.

Francis Bacon: Bacon states that things such as university never changed - it was merely a system of training clergy men and so on. Bacon was in such an institute and despised this - he violently turned on the Scholastics and Aristotelian approach and called their ideas barren and circular.

Bacon also claimed that the mixing of religion and science was a recipe for disaster because people are constantly trying to change the world - he wanted to break away from these somewhat outdated beliefs and other knowledge from the past that he deemed useless.

Francis Bacon and the New Organon: The Organon was the collective name of all of Aristotle's work. This 'New Organon' had 4 key themes. 
1) Knowledge is the source of human power, so we must harness and navigate through all knowledge. 
2) There must be a clear separation of science and religion, as mixing if caused too many problems in the past.
3) The idea "new knowledge" must be thought up from scratch - these ideas or general theories must be then tested to see if they can prove them, or more accurately in later years "falsify" them. 
4) Science is dynamic - you must always admit to failure when you encounter it as opposed to the archaic way of never admitting defeat or failure, this is the way that you learn.

The Scientific Method: This is the idea that you must always start a new theory from scratch - you must protect yourself from ideas from the past that might influence your ideas - it has to be original basically.

Locke and Human UnderstandingLocke believes that natural understanding comes from experience, as we know he also rejected the idea of innate knowledge. He believes that we are all born blank slates, we need experience to help us discover who we are, and furthermore, he believes that God has given us reason so that we can then understand what we are seeing.

The Heliocentric Model, Copernicus and Galileo: The Sun = Centre of the Universe. A 16th century polish man called Copernicus wanted to make a calendar.This idea of his was suppressed and offered to the world as a model of how you can calculate it, this is however not a true picture of reality.

Kepler heavily influenced Galileo and they managed to prefect the Dutch invention - the telescope. For the first time ever this allowed people to actually observe the heavens, this sort of this was un-dreamed of by previous generations - it was a true revelation. The telescope brought with it the power of observation and when you link this with mathematical proof gives you the idea of precedent over presumptive authority. For example, the scholastic system says that the moon is completely smooth, but with the telescope we now know that there in fact creators and mounds upon the moon’s surface and that Jupiter also had its own moons. Galileo attacked Aristotle and his ideas, mostly his distinction between primary and secondary qualities:

Primary = real and quantitative (things like shape, mass, measurable things and so on)

Secondary = placed on all Aristotelian qualities, we're not real in the object it all depends on perception

Isaac Newton: Newton published the book "Principia" in 1687 and it was a mathematical demonstration of what came beforehand (people such as Keplar and Copernicus). Newton convinced people that the world was ordered and knowable - this is when he first mentioned "The Clockwork Universe" 

After Newton, Aristotle’s physics is discredited and the whole of his system of thought were undermined, all thanks to the ideas put forward by Newton and the people after him. This is arguably the advent of the Enlightenment - which is the dominance of science until it is destroyed by Einstein in the 20th Century.

Phew! What a hell of a long blog post, anyway that’s my "summary" of the philosophy lecture on the clockwork universe. 

Bye and stuff, thanks for stopping by, stay classy x