Galileo, His Theories and the Church

Thesis- To examine Galileo's theories, find out why they were banned by the church and to discover the conclusion of this famous conflict of science and religion.

-Galileo was born February 15, 1564

- Taught at the University of Padua from 1592 to 1610

- Quickly came to disagree with the accepted principles of Aristotle and abandoned Ptolemy, who proposed the earth was the center of the universe and everything rotated around it, for Copernicus who believed in a Heliocentric universe or one that revolved around the sun.

-Copernican theory also stated earth had a daily rotation.

-This theory contradicted the bible which in several parts can be interpreted to say that the earth is static.

Arguments For Copernican Theory

-In 1609 Galileo built a telescope to examine the heavens and made several observations which lead him to except the Copernican Theory:

1. He noticed that Jupiter had smaller orbiting satellites which showed that not everything revolved around the earth as was postulated by the Ptolemic model.

2. That the moon wasn't a perfect sphere and it's surface was marred by mountains, valleys and craters much like earth. This was significant because in the previously accepted models of the universe it was thought all celestial bodies had a composition completely different from that of the earth. They were said to be made of a perfect element called quintessence which made their surfaces perfectly smooth and spherical. Which was obviously proved false by the views through the telescope with which Galileo could also see sunspots.

3. That Venus had phases like the moon, which could be explained by the fact that it moved around the sun as did the earth, so during parts of its orbit it would be closer to the earth and therefore brighter.

Arguments Against Copernican Theory

There where a number of arguments against the new and highly controversial theory:

-The fact that the sun rose in the mourning and set in the evening on opposite sides of the earth indicating it followed a circular path around the earth.

-That if the earth did have a daily rotation it would have to be at such speeds that the light gases that surrounded the earth would be blown off.

-By far the best argument against Copernican theory was that if the earth rotated around the sun that their would be a shift in a star position in the sky over time due to the distance the earth was traveling. This shift is called a star's parallax. (This argument was said to be a non-factor by Copernicans as they stated that stars must just be too far away and the parallax to small to be measured).

It was clear these arguments would not easily be overcome by Galileo in his effort to prove the validity of the Copernican theory without the use of a superior system of physics and instruments at hand.

Problems With Tycho

If it were a decision between just the Ptolemaic and Copernican systems, Galileo probably would have succeeded in having the Copernican system recognized as the correct one because it was simpler and seemed to better fit the set of observations.

-Tycho Brahe came up with a geocentric or earth centered theory where the sun revolved around the earth and all the planets revolved around the sun.

- This new theory fit all of Galileo's observations just as well as the Copernican system did.

Personal Beliefs

-Galileo believed Qualitative natural science had nothing to offer, and subjective science didn't matter because it could never be proven.

-Science could only be proven through the true language of the book of nature, Mathematics.

-That which cannot be measured belongs to the province of faith or belief.

-The Bible was not meant to teach science but religion and therefore can not be interpreted using its' bare grammatical value when it describes scientific phenomenon.

-These personal views led Galileo to heavily criticize the Jesuit scientists for their natural philosophy and in so doing made him many opponents.

-Galileo's beliefs did also attract influential friends such as Cardinal Barberini who later became Pope Urban VIII.

The Church Becomes Involved

- With this new theory to contend with Galileo sought to silence the critics of the Copernican theory by having the Church officially except the theory so he headed to Rome in 1611.

-While in Rome Galileo failed to get the Church to officially except his theory due to lack of physical proof. It was said by Saint Thomas that the bible could not confirm or deny one theory over another because the bible does not speak of science.

- After writing a letter in which he interpreted scripture to fit to his (Copernican) theory, which Galileo had hoped would sway the Church, he received much more attention from the Theological Consulators of the Holy Office.

-The Theologians didn't like the idea of a layman interpreting scripture to prove an idea and so they put the book De revoluntionibus in which Copernicus discusses his theory on the index of forbidden books in 1616 for being contrary to the Holy Scripture in saying that the earth moves.

-Also in 1616 Galileo is given a certificate by Cardinal Bellarmine that states he is not to defend or uphold the Copernican theory in any way.

Galileo Back in Trouble with the Church

-By 1619 Galileo re-enters controversy by writing the "Discourse on Comets" which attacks the ideas of a Jesuit priest but gets away with it as he publishes it under the name of his friend Mario Guiducci.

-The situation becomes more tense as Galileo sees his final opportunity to get the ban lifted on De revoluntionibus now that his friend Cardinal Barberini has become Pope Urban VIII.

-Pope Urban VIII refuses to lift the Ban on De revoluntionibus but lets Galileo write on the Copernican system as long as it was theoretical and that he admitted it was not the only possibility for the structure of the heavens.

-Meanwhile the opponents of the Copernican theory are becoming increasingly worried as Galileo seems to be gaining much favour.

The Dialogue is the Last Argument

-In 1632 Galileo writes the Dialogue on the Great World Systems.

-This book was a Socratic type conversation between three characters, Sulviati representing Galileo's views, Sagredo an impartial listener and Simplicico a simple Aristotelian. Basically it is a cleverly camouflaged book arguing the Copernican Theory.

-Galileo's enemies convince Pope UrbanVIII that he is the simple, small minded Aristotelian and that Galileo is mocking him.

-April 12, 1633 Feeling betrayed and humiliated Pope UrbanVIII summons Galileo to the Holy Office for trial.

-June 22, 1633 Galileo was sentenced as vehemently suspected of heresy, he was put on house arrest for the rest of his life.

-1637 Galileo suffered the loss of sight in both eyes and continued to work on his book, Discourses concerning Two New Sciences, which Sir Isaac Newton would use to help form the basics of his new physics.

-January 8, 1642 Galileo dies, the same year Newton is born.

Sources

Jerome J. Langford, Galileo Science and the Church

Stillman Drake, Galileo

Carlo L. Golino, Galileo Reappraised