Monday, 18 November 2013

The Scientific Revolution of the 16th and 17th Century.

This is some revision I was doing for an exam about the history of science. I found it really interesting how the development of science and the scientific method undermined and invalidated religious teachings some 400 years ago, you may do too. Any questions or corrections, please do leave a comment.

The scientific revolution of the 17th Century saw a paradigm shift from the Aristotelian view of the universe, which placed the earth at the centre of the universe (with wandering stars/planets and fixed stars in orbit), to Copernicus’s heliocentric model which acknowledged the fact that the earth and all observable planets within our solar system orbit the sun, setting in motion a chain of events that have shattered the foundations of Religious teachings.

The Aristotelian view of the universe suggested that everything was made of five elements. The area above the moon was the super-lunar region made of an incorruptible element called aether, and all stars were viewed as faultless objects moving in perfect harmony. The sub-lunar region was less orderly and everything was made up of a combination of the four elements earth, fire, wind and water susceptible to corruption and decay. Each element had a natural place either up or down; earth and water belonged near the centre of the earth, which was why solid objects, soil and water all fell to earth, and that fire and air belonged near the moons orbit which is why they travelled up.

In the sixteenth century, the Catholic Church supported the idea of the geocentric universe as it supported the claims that God had created the universe around Man, suppressing theories which challenged the status-quo. Around this time, interest in astronomy was growing as the Julian calendar was becoming out of sync with reality underestimating the length of a year by eleven minutes meaning that every 134 years one day was ‘missed.’ A year consists of 365.2425 days, not three years of 365 days followed by a 366 day leap year as was the case. As a consequence, by the sixteenth century the calendar was eleven days short and was eventually corrected in 1582, when the Julian calendar was replaced by the Gregorian calendar (which is still in use today), based on Ptolemy’s model and Thursday 4th of October was followed by Friday 15th October.

Ptolemy (Date) noticed a problem with the Aristotelian view of the universe. On successive nights, the wandering stars appeared to be displaced slightly to the east in comparison to the previous night, moreover these displacements were not fixed, sometimes moving in the opposite direction and then back again. Ptolemy introduced the term epicycles (Latin; a circle within a circle) to describe the phenomenon, small cycles that the fixed stars made in addition to their orbit around the earth. This still did not account for some oddities observed and led to more complex epicycles being proposed to explain the movements of some wandering stars.

Nicolaus Copernicus’s (1543) observations suggested that the order of the universe began with the sun, then Mercury, Venus, Earth, Mars, Jupiter, Saturn, surrounded by a sphere of immobile stars. The heliocentric universe was a fully predictable working mathematic model, although the idea had been suggested as early as 300BCE. Copernicus (1543) also suggested that the earth orbited the sun and took one year, instead of the daily orbit of the sun around the earth and that the earth rotated on its axis which caused night and day, and the movement of the fixed stars. Copernicus (1543) also added epicycles to his model to predict the movements of the wandering stars more precisely, although the problem would not be resolved until Johannes Kepler suggested that orbits were not circular, but elliptical.

Copernicus wrote a small commentary in 1514 and made it available to friends, but his work was not published until 1543 shortly before his death. Being employed by the Roman Catholic Church, the fear of reprisal was the most likely cause for the delay although Copernicus himself may have criticised his own model for lacking in evidence. The concept of gravity was not far from conception and many pieces of the puzzle were already there. The eventual complexity of Copernicus’s model contained epicycles the same as Ptolemy’s. Questions such as if the earth is spinning why don’t we fly off, if the earth is moving why do things stay stationary would not be answered until Isaac Newton introduced his laws of motion (1687). For some of these reasons, Copernicus’s model was not accepted and was only taught as an inferior model until after the invention of the telescope in 1609.

Galileo Galilei (1616) first tried to convince the Catholic Church of the heliocentric universe model but failed after he had built his own telescope spurred on by the observation of a Supernova, which led him to believe that new stars could be created in the super-lunar region and that the region was not as perfect and unchangeable as it was believed to be. Galileo observed; that there was many more stars than visible to the naked eye, that the moon was not smooth and flat as proposed by Aristotelian advocates (he could discern the mountains and craters because some surfaces were half lit when he looked at a half moon), Jupiter had four moons of its own and Mars and Venus changed size. In addition, Venus had phases like the moon, waxing and waning that suggested its orbit had a shorter diameter around the sun than earth.

These observations alone destroy the basis for Catholicism as well as other religions, and Galileo openly mocked the church in a book commissioned by the pope in which the protagonist who was named Simplicio (simpleton in Italian), possessed the views of the Catholic Church, for which he was tried for heresy. Galileo (1633) was forced to recant and placed under house arrest for the rest of his life much to the dismay of the intellectual community, and would eventually backfire as their actions drew more public attention.

Rene Descartes was one of the first to be affected by the Roman Catholic Church’s harsh treatment of Galileo and shelved a book (published 10 years after his death) he was about to publish called Le Monde, which also contained the heliocentric model of the universe. Descartes set about attempting to build a new philosophy, one that would not be at odds with religion, which ended up being as equally devastating to the status of the religious world view. As scientific understanding and technology advanced, the human body was beginning to be seen as a complex machine, as well as everything else in the material universe, so the first thing Descartes did was to separate the mind from the body coining the term dualism; the mind being immaterial and divine, impossible to study which left it up to philosophy and religion to explain as a soul cannot be studied scientifically.

Descartes was convinced that the human soul was born with innate knowledge that could be rediscovered through rationalism in order to help understand the workings of the gigantic perpetual motion machine that God have created to continuously look after his creation. This was Descartes second move, viewing the universe and all matter (including all other living things) as a big complicated machine that humans could study and the mechanistic view replaced the Aristotelian view as many new scientific discoveries did not fit, such as the five elements hypothesis. Aristotle’s thinking centred on four causes for phenomenon; the material cause (what it is made up of), the formal cause (the plan), the efficient cause (the processes) and the final cause (purpose). Because of this final cause, Aristotelian explanations of nature were referred to as perceived goals and aims of an object or phenomenon (e.g. the final cause of rain was to let plants grow). Renaissance scientists still retained the belief that things had souls which gave them purpose.

Descartes rejected the ideals of renaissance scientists and although he made a sharp division between religion and science, his views primarily benefited science. More importantly as was intended, further scrutiny and development of his work led to progress in psychology, the scientific study of mind and behaviour. Descartes believed that the soul was able to control the body via the pineal gland and this view was increasingly seen as unconvincing and as a consequence, the ‘soul’ was thrust into the mechanistic universe and became a subject of natural investigation.

Isaac Newton (1687) was the man who brought together all existing theories and formulated three basic laws with the postulation of a gravitational force. Newton’s insight was that objects were attracted to the earth because of its size and mass and also suggested that if a cannon ball was fired from high enough, it would orbit the earth instead of succumbing to gravity and falling to earth. Everything in the Copernican view of the universe and all movements on earth could now be calculated with incredible mathematical precision and are still valid today, with only the revision of Einstein’s theory of relativity. Scientists still do not understand why celestial bodies can attract over great distances without any apparent matter between them, although the discovery of the Higgs Boson particle will undoubtedly lead to further progress, as well as the super massive black hole theory.

Rationalism is a world view that was shared by Plato and Descartes which favoured using deductive reason and logic to uncover true conclusions from a number of indisputable premises suggesting that this was the only source of knowledge. By turning inwards, humans could examine innate knowledge and discover new conclusions by using logic which were guaranteed to be true. This world view was supported by the Catholic Church and dominated the middle ages.

Empiricism is the world view that all knowledge is learnt through perceptual experience and inductive reasoning should be used to reach general conclusions based on observations. John Locke (1689) is considered the father of Empiricism, publishing a book which defined the human mind at birth as a blank slate or “tabula rasa” upon which experiences left their mark and made associations with marks already present. It was no coincidence that An Essay Concerning Human Life was released a few years after Principia mathematica as Locke was an acquaintance of Newton. Empiricism suited natural philosophers well as they rapidly became convinced that knowledge; including science, had to start from meticulous observation.

Astronomers of the time warned about the blind reliance of human observations as perceptions of a fixed world view had given the false impression of a geocentric universe up until Copernicus’s theory was more widely accepted after the discovery of Venus’s phases and Jupiter’s moons. Human perception had been shown to be fallible and limited in the past and an air of caution was needed. The scientific method proposes two remedies for circumventing the limits of human observation. The first was to formulate hypothesis by using existing knowledge and deductive reasoning. Hypothesises are then tested by experimentation and once a phenomenon is understood , it should be possible to make a new prediction on the basis of what is already known and to check empirically whether experimental manipulations have an effect.

The second remedy for the unreliability of human observation was the progress and use of technology. Just like the telescope in 1609, the microscope would offer a completely new way of viewing the world and universe. One prominent area of profitable scientific research after physics was chemistry, which was previously known as a widely erratic business of alchemy to which Isaac Newton devoted more of his time than physics. Within a few decades chemistry became as repeatable and reputable as physics with the rapid discovery of chemical elements and the laws that governed them. Robert Boyle (1662) published a law on the behaviour of gas and is seen as many chemists as another central figure to the scientific revolution.

            The 16th and 17th Century saw a paradigm shift away from accepting ancient ideas of religion and that authority should not be questioned, to the active pursuit of questioning nature. Before the scientific revolution; institutions such as the church backed by authority figures and religious philosophers controlled what was commonly thought about the world.

Why this isn't taught in schools is beyond me!