Friday, August 19, 2011

Science and the change in world view

The Creation of the World and the Expulsion from Paradise
Giovanni di Paolo (Italian (Sienese), ca. 1400 - 1482)

I think I am going to begin a series of posts on scientific ideas that have or should have changed our view of the world. The obvious place to start is Copernicus, Galileo and Newton. Copernicus not only proposed that the earth revolved around the sun (while the earth was also revolving about its axis), but demonstrated that that assumption could be used as the basis to accurately predict the observations of the sun's place in the sky. He published the book proposing and defending that theory in 1543.

Giordano Bruno went beyond Copernicus to postulate that the sun was a star, differing from other stars in that it was much closer to the earth than the other stars. He was executed for heresy in 1600.

Galileo observed that the moons of Jupiter revolved around the planet, not only accepting the Copernican idea that the earth revolved around the sun but that moons revolved around the earth and other planets. He observed the stars with a telescope, accepting Bruno's hypothesis that they were also suns, and recognizing by their size that that they were very far away indeed. (It was not until 1838 the Friedrick Bessel first measured the distance to a star other than the sun, showing that that distance was very great.) Galileo also observed the moon surface to be uneven, and noted that sunspots changed the appearance of the sun as they moved over its surface. He was tried for heresy in 1632 and forced to recant.

In 1665 Newton generalized the theory of gravity to celestial distances. He showed that the movement of objects in the solar system could be explained by the operation of "natural" forces and "natural" laws.

The understanding of the sky held "religiously" in western civilization before these scientists went back to Aristotle and Ptolemy. It conceived of the stars and planets as being mounted on celestial spheres around the earth, with differing views on the nature of the spheres and the way they were motivated.

They scientists introduced a view in which the solar system was composed of real objects moving according to natural laws, with the earth as but one of the planets circling the sun, and the entire system a small part of a universe containing very distant stars.

According to Wikipedia:
On 31 October 1992, Pope John Paul II expressed regret for how the Galileo affair was handled, and issued a declaration acknowledging the errors committed by the Catholic Church tribunal that judged the scientific positions of Galileo Galilei, as the result of a study conducted by the Pontifical Council for Culture.


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