Study guide for Christopher M. Graney, (Notre Dame, IN: Notre Dame University Press, 2015).
If Graney does not explain something, or mentions someone you don’t know, I expect you to find that information for yourself. Some of the questions below direct you to find this kind of background information.
1. How old was Riccioli when Galileo died?
2. Who wrote the original Almagest? What was it about?
3. How many cosmic plans are shown on the frontispiece of the New Almagest ?
4. What are the main differences between these plans?
5. What does their arrangement in the frontispiece tell you?
6. In this chapter, what are main arguments that are mentioned for and against the different plans?
7. What are the largest and smallest objects in the heavens when viewed by the human eye alone?
8. What are the five elements that make up the cosmos, according to Aristotle?
9. How does each of these elements move naturally, that is, when left to itself?
10. Who was Jean Buridan, when did he live, and how did his theory of motion differ from Aristotle’s?
11. What grounds did Aristotle and Buridan have for believing the Earth to be a sphere?
12. What grounds did Aristotle and Buridan have for believing that the heavens are enormously larger than the earth?
13. Why did Aristotle and Buridan believe that object further from the Earth moved faster than objects close to it?
14. How can diurnal parallax be used to establish the relative distances of objects from the Earth?
15. Where is Hven?
16. How large is the instrument in Figure 3.2 compared to a human being? Find the same instrument in this picture of Tycho's observatory
to answer the question. Why are bigger instruments better for Tycho Brahe?
17. What key modern astronomical instrument did Tycho Brahe lack? Why?
18. What observations require that Copernicus’s sun centered cosmos is bigger than Aristotle’s earth centered cosmos?
19. How does Tycho turn the greater size of Copernicus’s cosmos into an argument against a sun centered cosmos?
20. How does Tycho use information about the path of cannon balls in arguments against a sun centered cosmos?
21. Where and when were telescopes invented?
21. What did stars look like to Galileo when he first saw them through a telescope? What was his mature judgement of their appearance?
22. What is “differential parallax” (see also Figure 3.6)
23. Why are Galileo’s observations of double stars a problem for Copernicus’s cosmos?
24. Why are the observations of (apparent) stellar discs, by Galileo, Marius and perhaps Crüger, a problem for Copernicus’s cosmos?
25. How does Galileo deal with these problems?
26. How does a small telescope (20 power or 40 power) change the appearance of:
(1) objects on the earth (2) the moon (3) planets like Venus or Jupiter (4) stars?
27. How did Galileo explain the apparent difference between size estimates based on the unaided eye and the telescope?
28. What is the modern explanation for these effects?
29. Compare Figures 4.1 and 5.2 with the diagram you drew in class. Which image corresponds to each position for Venus in your diagram?
30. What was Galileo's occupation when Locher published his book?
31. What did Johann Georg Locher mean when he said "Because of the arrangement of the parts of the Universe and the imagined motion of the Earth in [the Copernican] hypothesis, the Sun, Mercury and Venus are below, and the Earth is above"? Why did Joshua command the Sun the stand still? Would Joshua's success be problem for the Copernican hypothesis?
32. How many arguments, in total does Locher make against the Copernican hypothesis?
33. What was Galileo's doing when Francesco Ingoli finished his essay against the Copernican hypothesis?
34. Besides finding them "foolish and absurd in philosophy", what did the Holy Office's (Inquisition's) committee of consultants say about the two Copernican theses, that the sun is stationary at the center of the world, and that the earth is not the center of the world but moves with both an annual and a daily motion? Which judgement is more dangerous? Click HERE to read the consultants' report.
35. How many objections to the Copernican hypothesis did Ingoli make in his essay. Which did he emphasize?
36. What was Cardinal Roberto Bellarmine's opinion of the Copernican hypothesis?
37. How did Phillip Landsbergen defend the Copernican hypothesis?
38. Apart from the language used, what is the most conspicuous difference between Thomas Digges image of the Copernican hypothesis (Figure 5.4) and that of Copernicus himself?
39. Given the evidence presented in this chapter, were the arguments against the Copernican hypothesis made by Catholics, including the Inquisition, around 1616, predominantly religious or scientific?
40. How did Riccioli (and his assistants) measure time?
41. How did they calibrate (ensure the accuracy) their timekeeping devices?
43. How accurate were their timekeeping devices?
44. What difference would you notice if you drop a ball into a (presumably metal?) bowl from 10ft and then from 20ft? According to Riccioli what does this tell you?
45. Why did Riccioli not believe Galileo’s 1,3 5,7 rule? What did he do when he found Galileo was right?
46. How did Riccioli evaluate Galileo’s claim that all bodies fall at the same rate?
47. Throughout this chapter Graney describes many qualities of Riccioli that we would admire in a modern scientist. What were they and how many did Galileo himself share?
48. What were the 126 arguments about and how were they divided?
49. Why did Riccioli consider only the systems of Tycho and Copernicus in his comparison?
50. Did Riccioli consider all 126 arguments equally plausible?
51. What was wrong with the Copernican suggestion to retain Aristotle’s physics of the elements for the region inside the moon’s orbit, and simply have the whole earth-moon system carried around the sun by the earth’s annual motion?
52. How many natural motions does a falling body need to have in Copernicus’ system?
53. Who originated the Copernican arguments about sunspots and the tides?
54. What did all the decisive arguments against Copernicanism have in common?
55. What was the angel holding, and what happened to it?
56. If the earth is rotating, what should happen to balls shot from identical cannons, pointing East and West, firing at identical targets at the same height?
57. According to Isaac Newton, when a ball is dropped from the top of a tall tower, should it fall to the East or the West?
58. How successful were attempts to measure any of these consequences of the earth’s rotation?
59. How could a Copernican respond?
60. What is the modern name given to all these effects?
61. What were the main arguments against the size of the Copernican universe?
62. How could a Copernican respond?
63. Why does Graney invert the usual identification of the opposing sides in the heliocentrism dispute, and suggest that the Copernicans who illicitly used religion where they lacked a scientific answer?
Here Graney wraps things up by telling you the modern view of the issues under debate. By all means read this, but remember that, to decide whether Galileo was guilty in 1633, we can consider only information available in 1633. Whether Galileo is right according to modern science is a different question. Also, remember all the things Galileo got wrong, e.g. the tides.
64. According to Graney’s alternate universe narrative (pp. 143-4), what would have been the rational choice before 1689 – the date Newton published: heliocentrism or geocentrism?
65. What is a Foucault pendulum? When was the first one built? Where is the nearest one?
66. What were astronomers who measured the visible diameters of stars really seeing? Why did smoked glass make the observations easier?
67. How did Bradley’s discovery of stellar aberration show that the earth moves?
69. How did Ole Roemer’observations of Jupiter’s moons show that the earth moves?
70. On balance, between 1633 and 1689, did the balance of scientific evidence favor Copernicanism?
(c) Peter Barker 2016, 2018