1. The Copernican Revolution – A New Earth? Unit 3 - Day 3

2. A Paradigm Shift? In his book, The Copernican Revolution, noted historian of science Thomas Kuhn argues that Copernicus’s work on astronomy brought about a paradigm shift in the way people saw the world. Question: What is a paradigm? Paradigm – a way of viewing or understanding reality Question: How can one’s paradigm shift? Paradigm Shift – Kuhn argued that a paradigm shift occurs when a person or community is presented with evidence that cannot be explained by the currently accepted way of viewing or understanding reality.

3. Paradigm Shift – A Simulation

4. Paradigm Shift – A Simulation 2 Note: Neither of these images “are” paradigm shifts. They simulate the experience by showing how we can interpret the same information in two different ways, and move back and forth between the two interpretations.

5. Nicholas Copernicus Nicholas Copernicus (1473-1543)  Born in Polish city of Torun  Father dies when he is young, raised by uncle an influential bishop  Studies at the University of Krakow  Goes to Italy to earn doctorate in Law and study medicine  Upon return, becomes a canon (cleric) and serves as an administrator for bishop  Dabbles in mathematics and astronomy as a hobby.  Makes astronomical tables based on his observations.  1510-1514 becomes involved in Church calendar reform – formulates heliocentric theory

6. Heliocentric Theory

7. Calendar Reform Problems with existing mathematical models for calculating calendar: 1.Models are mostly accurate but require periodic “reboots” every few hundred years. 2.Mars does funky things. Aristotelian model needs complicated solutions. Retrograde motion of Mars – time-lapse photo

8. The Mars Problem How Aristotelian astronomers explain retrograde motion with epicycles. For Copernicus the solution to retrograde motion is simple – the Earth (which moves) simply passes Mars

9. Copernicus Discussion Questions What does Copernicus think is wrong with the way that mathematicians have gone about solving the problems with the existing calendar? Why does he decide to approach the problem differently? Why does he believe his model provides a better solution to the problem? What concerns does he have about the way his theory will be received? What does he feel is the proper relationship between reason and authority?

10. On the Revolutions (1543)  1514 Copernicus distributes a pamphlet called the Commentaries which sketches out his conclusions to his friends and other mathematicians  1543 – finally publishes On the Revolutions on the Heavenly Spheres; containing hundreds of pages of dense calculations – which only mathematicians can read  Caused very little immediate controversy – in part because it was widely seen as just a tool for calculation not a real system.