Study Guide for Pedersen Early Physics and Astronomy 2nd ed. 1993.

For use in HSCI 3013: Instructor Peter Barker

Look at these questions before you read a given chapter and make brief notes on the answer as the topic appears in your reading. These questions give a preliminary indication of what I consider important -- but lectures are the best source.

Chapter 1. Science before the Greeks.

Vocab: An inundation is a flood. The Nile flooded every year, and sediment fertilized the fields it overflowed.

Sal ammoniac (NH4Cl); soda (Na2CO3 or NaHCO3); potash (K2CO3 or KOH); alum (AlK(SO4)2); nitre (KNO3);

Sexagesimal mathematics uses 60 where decimal mathematics uses 10. Examples: Hours, minutes & seconds.

1.1. "Natural science was created by the Greeks." Is this true?

1.2. What two kinds of motives does P. suggest for the development of natural science?

1.3. What essential general features did science before the Greeks lack?

1.4. What is the difference between a mythological and a causal explanation?

1.5. What is the difference between astrology and astronomy?

Chapter 2: The New Concept of Nature

2.1. Why does adopting a religion with a single god (monotheism) undermine mythological explanations of nature? (cf. 1.4)

2.2. Who, according to tradition, was the first Ionian philosopher?

2.3. What are the two main meanings of physis (pronounced: 'foo-sis')?

2.4. What did Thales think the fundamental substance was?

2.5. What was the shape of the earth according to Thales, and what supported it?

2.6. Why is the attribution of geometrical proofs to Thales important? Why is his explanation of the annual flooding of the Nile important? (cf. 1.3)

2.7. Who was Anaximander's teacher?

2.8. What shape did Anaximander think the earth was?

2.9. What shape did Anaximander think a (complete) heavenly body was?

2.10. What did Anaximander think was the order of the heavenly bodies?

Vocab: Hellas is an ancient name for Greece.

2.11. What did an advanced student of Pythagoras study?

2.12. What important general principle was suggested by Pythagorean experiments with a monochord (a single string on a sounding board)?

2.13. What change in Pythagorean doctrine was compelled by the discovery of incommensurable numbers?

2.14. What kind of book is Euclid's Elements?

Chapter 3: Plato and Greek mathematics

3.1 Who was Plato's teacher?

3.2 What is epistemology a theory of?

3.3 For Plato, where does knowledge come from?

3.4 For Plato, what is an idea?

3.5 What is metaphysics? (A very hard question!)

3.6 Which are more fundamental for Plato, everyday things, mathematical things or ideas?

3.7 According to Plato, what is the proper goal of astronomy?

3.8 According to Simplikios and later writers how should Plato's goal be achieved?

3.9 What was the demiurge?

3.10 What was the nature of the planets according to Plato?

3.11 Which is more important for Plato, theory or experiment?

Chapter 4: Aristotle and Knowledge of Nature (plus other material on Aristotle).

4.1 How do Aristotle's views on mathematics differ from Plato's?

4.2 What are the metaphysical constituents of physical objects for Aristotle?

4.3 "Suppose you had never seen a wheel. Could you know what one was?" How would Platoa and Aristotle differ in answering this question?

4.4 What does Pedersen consider to be Aristotle's main philosophical achievement?

4.5 What does Aristotle mean by physics and how does it differ from the modern subject?

4.6 How is physics related to mathematics and metaphysics?

4.7 What are the four types of cause recognized by Aristotle? What are examples of each?

(Now skip to Chapter 11 pp. 123-8)

11.1 What are the four basic substances recognized by Empedocles and his successors?

11.2 How may an everyday phenomenon like a log fire be analyzed in terms of these for substance?

11.3 How did Plato explain the differences between the four elements?

11.4 How does Aristotle generate the elements from the pairs of opposites hot-cold and wet-dry?

Chapter 5: Practical Astronomy

5.1 Which early Greek thinker understood that the morning star and the evening star were a single object, and that the Moon did not shine by its own light?

5.2 In addition to rising in the East and setting in the West each day, what is the direction of the planets' direct or proper motion?

5.3 What is a gnomon, and what is one of the things it can be used to measure?

5.4 What is a polos and what is one of the things it can be used to measure?

5.5 Which are the longest and shortest seasons?

5.6 What is a scaphae and what is one of the things it can be used to measure?

5.7 Why were Summer hours longer than Winter hours when measured on a sundial?

5.8 What important mathematical subjects does Pedersen believe were discovered while analysing sundials that use a gnomon?

5.9 What three proofs did Aristotle offer for the shape of the earth?

5.10 How did Eratosthenes calculate the circumference of the Earth? How accurate is his value?

5.11 Greek astronomers from Aristachos to Ptolemy calculated the distances of the Moon and the Sun. Which distance shows least variation, and why?

5.12 What did Hipparchos keep in his star catalog?

5.13 What important annual motion did Hipparchos discover?

5.14 Why did Hipparchus compute a list of eclipses of the Moon?

5.15 Given Pedersen's account of Greek practical astronomy, appraise the claim that Greek science was exclusively concerned with theoretical speculation.

Chapter 6: Cosmology


Geocentric = earth centered (from Greek 'geos' = earth, cf. GEOlogy - the study of the earth)

Heliocentric = Sun centered (from Greek 'helios' = sun, cf. HELIOtrope - a plant that turns towards the Sun)

6.1 What shape was the Pythagoreans' universe, and what was in the center? Where was the Sun?

[Pedersen p. 52: The first sentence of the last paragraph should read "Leaving the anti-Earth and the central fire out of account...]

6.2 What produced the Music of the Spheres, and why didn't anyone hear it?

6.3 According to Heracleides of Pontos, what was the center of the universe? How did the motions of Venus and Mercury differ from those of other planets?

6.4 What discoveries in practical astronomy may account for the different orders of the planets given in Plato's Timaios , Republic and Epinomis? (Cf. 6.3, 5.1, 5.11)

6.5 How many motions has a planet in Plato's universe? (Question to be answered in class: What will be the resultant path as seen against the background of the fixed stars?)

Chapter 7: Mathematical astronomy

(Note from PB -- don't worry about the maths unless you like it. Concentrate on what the maths is used for.)

7.1 In what way did Plato limit the possible solutions to the problem of planetary motion?

7.2 What are the four motions that every planet makes?

7.3 Why is the sidereal year different from the tropical year? (cf. 5.13)

7.4 Where is the Sun when Mars, Jupiter or Saturn are in the middle of a retrograde arc?

7.5 What is the center of Eudoxus' concentric spheres?

7.6 How many spheres does Eudoxus employ to explain the motions of the Sun and Moon? What role does each play?

7.7 How did Eudoxus avoid having an eclipse every full or new moon?

7.8 What is the Saros period?

7.9 What shape is a Hippopede? Which planetary motion did Eudoxus hope to represent by means of it?

7.10 How many spheres does Eudoxus require to account for the motion of each planet?

7.11 How many spheres are there in Eudoxus's universe? (Question to be answered in class: How many spheres are there in Aristotle's universe?)

7.12 What are some of the objections to Eudoxus models for the Sun, Moon and planets?

7.13 Draw an eccentric circle, like those used by Apollonius. Mark the position of the Earth, the center of the eccentric and the planet.

7.14 Draw an epicycle on a deferent circle, like those used by Apollonius. Mark the position of the Earth, the center of the epicycle and the planet.

[Note: skip p. 72-3 -- too many misprints]

7.15 Which of Apollonius's models did Hipparchus adopt to represent the motion of the Sun?

7.16 Which of Apollonius's models did Hipparchus adopt to represent the motion of the Moon?

[Note: Klaudios Ptolemaios = Claudius Ptolemy]

7.17 How did Ptolemy's great book on astronomy come to be called the Almagest?

7.18 What model of the Sun's motion does Ptolemy adopt?

7.19 What three mathematical devices developed by Hipparchus and Appolonius does Ptolemy adopt to explain the motion of the Moon?

7.20 How does the position of the Sun enter into Ptolemy's account of the motion of the Moon?

7.21 How does the apparent diameter of the Moon change during a month, on Ptolemy's model?

7.22 What is 'Superior' about the 'Superior planets'?

7.23 What additional mathematical device does Ptolemy introduce in the models of the planets' motions, in addition to those used in the model for the Moon?

7.24 How does the position of the Sun enter into Ptolemy's account of the motion of the planets?

7.25 In comparison to the calculation of longitudes, how much of the Almagest is devoted to the calculation of latitudes?

7.26 Do Ptolemy's models require planets to move in ways that would be impossible if they were held up by Aristotle's spheres?

7.28 How would Aristotle and Ptolemy answer the question: "What is outside the universe?"

Skip Ch.s 8,9,10. We have already covered most of Ch. 11.

Look at the first part of Ch. 12, pp. 134-140, for further examples of Greek and Roman advanced technology that might have been applied to industrial mass production but was not.

Alchemy (pp. 140-149)

12.1 Why does Pedersen count Aristotle's Meteorology as the earliest book on chemistry?

12.2 Was alchemy a Greek invention? If not, which other cultures contributed?

12.3 Which ancient cosmology is recalled when we speak of distilling spirits like brandy or whisky?

12.4 Why did alchemists believe that the co-operation of heavenly bodies was necessary for a chemical process to take place?

12.5 What ideas did Greek, Babylonian and oriental sources contribute to alchemy?

12.6 What was an alembic and how was it used?

12.7 What was Greek Fire and how was it used?

12.8 What distinguishes alchemy from chemistry?

Islamic Science - Chapter 13, pp. 150-165, etc.

Vocab: Hellenic = Greek; Hellenistic = influenced by the Greeks

13.1 Do we know why ancient science stagnated after Ptolemy and Galen?

13.2 Byzantium was the chief city of what political entity?

13.3 Who closed Plato's Academy, when and why? How many centuries had the academy been in operation when it was closed?

13.4 Where does Pedersen locate the scientific center of the world in the period from the decline of Rome to the rise of Islam?

13.5 What was The House of Wisdom and who established it?

13.6 From which languages did Arab scientists translate earlier books?

13.7 A fundamental problem in Islamic astronomy is finding the qibla. What is the qibla and why is it important to find it?

13.8 What united the Muslims, Jews, Christians and pagans of the Moslem world?

13.9 What was tabulated in the Handy tables, the Toledan tables, and the Alphonsine tables?

13.10 How did al-Ma'mun determine the circumference of the earth?

13.14 What distinguishes the astronomical work of al-Farghani, al-Battani, and al-Kindi, from the later work of Ibn al-Haitham?

13.15 What is trepidation, and how did Thabit ibn Qurra explain it in his book On the Motion of the Eighth Sphere? How was his proposal greeted by his contemporaries and successors?

13.16 What are some examples of Islamic progress in technology?

[Skip from p. 165 to p. 234]

18.1 What were Jabir ibn Aflah's criticisms of Ptolemy?

18.2 Who was 'The Commentator' and what did he comment on?

18.3 Which ancient astronomer did Ibn Rushd and al-Bitruji prefer to Ptolemy? What was the basis for their preference?

[18.4 How did Oresme reconcile the possible motion of the Earth with Biblical passages that seemed to contradict it?]

18.5 On what grounds did Ibn al-Haitham criticize Ptolemy?

18.6 Who was Nasir al-Din al-Tusi, who employed him, and what was the name of the observatory he founded?

18.7 What is the path of the reference point moved by Al-Tusi's device of a small circle rolling inside a larger one (now called a Tusi couple)? Is this embarrassing for Aristotle?

18.8 Which mathematical device used by Ptolemy is rejected in favor of Tusi couples al-Tusi and his followers?

18.9 How does Ibn ash-Shatir's model for the motion of the Sun differ from Ptolemy's?

18.10 How does Ibn ash-Shatir's model for the motion of the Moon differ from Ptolemy's?

Copyright © Peter Barker 1996

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