SciRev Assignment 2

Week of 9/10/08


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Back to Syllabus [SciRevF08]

PDF readings in the eLibrary for this week require a password to open.

Email me if you don’t know this password.

Always read over the entire assignment page.

The Big Dipper, the Little Dipper, and the North Star (Polaris)

The North Star appears to be about 4.5 lengths (measured by Merak to Dubhe distance)

from the tip of the bowl of the Big Dipper and along the same line as the two stars indicated.

Polaris stays put for all practical purposes and the Big Dipper (and all the other “fixed” stars) will rotate around it every 24 hours.

Question: Which way does it rotate?


Read: Here is a short description of Ptolemaic celestial mechanics that may help with the Copernicus readings.  I went over some of this in class, but very quickly.  This is only a few pages long and the drawings pretty much explains the basics.



Also, here are a couple of Ptolemaic movies to jog your memory:

Mars for Windows

Mars for Mac or MacMars

A zoomable Ptolemaic cosmos.

Tons of these animations can be found here:

Read pp. 121-222 in Koestler.  (This is all of Part 3, “The Timid Canon.”)

Read one of the following excerpts from Rheticus’ (actually Copernicus’)  Narratio Prima (1540) [First Narration].


This is a summary of Copernicus’ theory.  Choose from the following sections.


-pp. 109-115

-pp. 136-140

-pp. 140-147

-pp. 162-168

Read the following excerpts from Book I of Copernicus’ De revolutionibus orbium coelestium, Libri VI, On the Revolutions of the Heavenly Spheres, in Six Books, (1543)


[Also included in this PDF are a few chapters from Book VI.


1) Read over the Foreword by Andreas Osiander found on pp. 3-4 of the PDF.

2) Look over the Table of Contents for the entire treatise on pp. 28-34 of the PDF.

3) Read Chapter 10 of Book I found on pages 14-17 of the PDF.

The following writing assignment is one of the assignments that counts towards the 5 total.  I you have no idea what this means, reread the class policies page linked on the Syllabus.  Assuming you did last week’s assignment (the comic bookish thing based on Ibn Tufayl) you have 4 left to do.  You may choose to do this one or you may choose to skip it and wait for one another one.

Homework: Write up an analysis [approximately 1.5 single-spaced pages or 3 if “souped-up”] of one or several of the readings assigned above (or from the optional readings below).  I am impressed when you refer to all parts of the assigned readings, but this isn’t always necessary if you have something good to say.  Remember, these homework assignments are exercises in critical thinking and also verifications that you are reading the assignments. Make diagrams and use more modern tools if you think it will help clarify your descriptions.  In these astronomical topics, diagrams are frequently necessary. You could summarize his arguments and comment on them or if something confuses you, figure it out.  Feel free to use an outside source.  But  remember, I have read these assignments and have already taken notes on them.  Don’t just rehash this stuff.  I will be bored, and I really hate being bored.   Souped-up homework assignments should definitely use an outside source (several are provided below).  Cite all sources.


Possible idea #1: Come up with a good way to explain how retrograde motions works in Copernican system.  This will almost certainly require you to make some diagrams or movies or something.  Also outline how retrograde motion is explained in Ptolemy’s system. 

Possible idea #2: Analyze how Copernicus argues for a spherical earth or cosmos or for the planetary order or for the sun being in the center.  Are his arguments convincing in our modern context or are his arguments weak and based on beliefs that are no longer relevant?  You could also compare his arguments with those of Ibn Tufayl who also makes some spherical observations.

Possible idea #3: Analyze Koestler’s description of Copernicus in terms of politics or religion or some other way.  Does Koestler have an agenda?  [This would require that you do some research on Koestler and might lead you into a souped up essay. I did not include any critical material on Koestler, but if this interests you, contact me and I’ll dredge up something.]

These “Possible ideas” are just off the top of my head.  Use your brains and come up with something.  Make it interesting.  Follow your instincts.  Make me want to read your homework.  Spend a little time laying it out attractively.  I want to read you and your ideas somewhere in these assignments.  Feel free to write in an informal style if you think this will help you think better.  However, even informal essays need citations.

If you are unsure, email me and ask questions.


Be ready for a possible quiz.

Here are citations to the readings for this week along with some additional optional sources that could be used for a “souped-up” homework.  Please feel free to use sources not listed in this bibliography.  This is by no means complete. 


Brotons, Victor Navarro. "The Reception of Copernicus in Sixteenth-Century Spain: The Case of Diego De Zuniga." Isis 86, no. 1 (1995): 52-78. Brotons_ReceptionCopernicus16thc.Spain-Zuniga.pdf [1.2 MB]


Cohen, I. Bernard. The Birth of a New Physics. Revised and updated ed. New York: W.W. Norton, 1985. [check library] 


Cole, Richard. "Ptolemy and Copernicus." The Philosophical Review 71, no. 4 (1962): 476-482. Cole_PtolemyandCopernicus.pdf [184 KB]


Copernicus, Nicholas. De Revolutionibus Orbium Coelestium; Books I and VI. Translated by and with Introduction and Notes by Edward Rosen.  New York: Dartmouth College, Sept. 1999 accessed 2004; Available from  [assigned above]


Copernicus, Nicholas, and Rheticus. "The Narratio Prima of Rheticus." In Three Copernican Treatises. Translated by and with Introduction and Notes by Edward Rosen. New York: Dover Publications, Inc., 1959. [assigned above]


________. De Revolutionibus Orbium Coelestium. Introduction by Professor Johannes Müller. New York: Johnson Reprint Corporation, 1965, Facsimile of 1st edition from 1543, originally owned by Kepler. [a few pages have been included in the reading in the assignment above]


Heath, Thomas Little, and Aristarchus. Aristarchus of Samos, the Ancient Copernicus; a History of Greek Astronomy to Aristarchus, Together with Aristarchus's Treatise on the Sizes and Distances of the Sun and Moon. Oxford,: Clarendon press, 1913. [check library]


Koyré, Alexandre. From the Closed World to the Infinite Universe. New York: Harper & Brothers, 1958. [check library]


________. The Astronomical Revolution : Copernicus, Kepler, Borelli. New York: Dover, 1992. [check library]


Kuhn, Thomas S. The Copernican Revolution. Cambridge, Mass.: Harvard University Press, 1985. [check library]


Lindberg, David C. The Beginnings of Western Science : The European Scientific Tradition in Philosophical, Religious, and Institutional Context, 600 B.C. To A.D. 1450. Chicago: University of Chicago Press, 1992.


Mossakowski, Stanislaw. "The Symbolic Meaning of Copernicus' Seal." Journal of the History of Ideas 34, no. 3 (1973): 451-460. Mossakowski_CopernicusSeal-375KB.pdf.


von Erhardt, Rudolf, and Erika von Erhardt-Siebold. "Archimedes' Sand-Reckoner: Aristarchus and Copernicus." Isis 33, no. 5 (1942): 578-602. Erhardt-Seibold_ArchimedesSandReckonerAristarchusCopernicus-3.3MB .pdf


Zilsel, Edgar. "Copernicus and Mechanics." Journal of the History of Ideas 1, no. 1 (1940): 113-118. Zilsel_CopernicusandMechanics-188KB.pdf



This is a reproduction from the manuscript by Copernicus.

[available here:]

In comparing this with the printed version [below] I notice that the labels are below the circular lines rather than sitting above them as in the printed edition.  Also the sun is just a word and the moon is not shown at all.  Is this significant?  I really don’t know, but this manuscript drawing seems to more clearly imply a finite and contained universe, with the sphere of the fixed stars clearly enclosing the universe, whereas the printed version suggests something outside this sphere.  This is more of an issue with Aristotle, but later theological debates over the size of the universe and the possibility of other worlds might have been exacerbated by the somewhat ambiguous diagram in the printed version.


The Latin text surrounding this diagram reads as follows.  The exact section shown in the page image above is in blue.


The sphere of the fixed stars is followed by the first of the planets, Saturn, which completes its circuit in 30 years. After Saturn, Jupiter accomplishes its revolution in 12 years. Then Mars revolves in 2 years. The annual revolution takes the series’ fourth place, which contains the earth, as I said [earlier in I, 10], together with the lunar sphere as an epicycle. In the fifth place Venus returns in 9 months. Lastly, the sixth place is held by Mercury, which revolves in a period of 80 days.


[You will note that the numbers on this diagram do not correspond with the text that surrounds this illustration. I have two theories for this. 1) This can be explained by the difference between cardinal and ordinal numbers.  In your first year of life you are not yet one year old. When you are finally one year old you are in your second year of life.  The diagram uses cardinal numbers while the description uses ordinal.  2) In the text Saturn is the first planetary sphere as distinguished from the sphere of fixed stars.  Either way, his presentation is a bit confusing.]


At rest, however, in the middle of everything is the sun. For in this most beautiful temple, who would place this lamp in another or better position than that from which it can light up the whole thing at the same time? For, the sun is not inappropriately called by some people the lantern of the universe, its mind by others, and its ruler by still others. [Hermes] the Thrice Greatest labels it a visible god, and Sophocles’ Electra, the all-seeing. Thus indeed, as though seated on a royal throne, the sun governs the family of planets revolving around it. Moreover, the earth is not deprived of the moon’s attendance. On the contrary, as Aristotle says in a work on animals [De anima? On the Soul?], the moon has the closest kinship with the earth. Meanwhile the earth has intercourse with the sun, and is impregnated for its yearly parturition.


[The earth has intercourse with the sun and is impregnated.  That’s an interesting description.]


In this arrangement, therefore, we discover a marvelous symmetry of the universe, and an established harmonious linkage between the motion of the spheres  and their size, such as can be found in no other way. For this permits a not inattentive student to perceive why the forward and backward arcs appear greater in Jupiter than in Saturn and smaller than in Mars, and on the other hand greater in Venus than in Mercury. This reversal in direction appears more frequently in Saturn than in Jupiter, and also more rarely in Mars and Venus than in Mercury. Moreover, when Saturn, Jupiter, and Mars rise at sunset, they are nearer to the earth than when they set in the evening or appear at a later hour. But Mars in particular, when it shines all night, seems to equal Jupiter in size, being distinguished only by its reddish color. Yet in the other configurations it is found barely among the stars of the second magnitude, being recognized by those who track it with assiduous observations. All these phenomena proceed from the same cause, which is in the earth’s motion.


Copernicus, Nicholas. De Revolutionibus Orbium Coelestium; Translated by Edward Rosen. New York: Dartmouth College, Sept. 1999 accessed 2004; Available from


Sun Centered Copernican System, first proposed in public in 1540.

Sun-Mercury-Venus-Earth (with moon)-Mars-Jupiter-Saturn-Starry Sphere

This image and the detail from it is from 1543, Book I, Chapter X of

On the Revolutions of the Heavenly Spheres.

Here are the translations of the spherical captions. 


I. Immobile sphere of the fixed stars

II. Saturn, is turned in 30 years

III. Twelve-year revolution of Jupiter

IV. Two-year revolution of Mars

V. Earth (Tellus), with the orb of the moon …[?] …

VI. Venus nine month return

VII. Mercury … [?] …80 days

VIII. The Sun

Here is a nice Copernican retrograde motion of Mars movie:


Review Material: posted 10/10/08






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Special Notice: CERN (the Large Hadron Collider) is starting up on Wednesday. 

Assuming everything goes as hoped we will still have class Wednesday evening. 

If not, we probably won’t know the difference anyway.



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