Epicycle Quotes (4 quotes)
Epicycles Quotes
Epicycles Quotes
From man or angel the great Architect did wisely to conceal, and not divulge his secrets to be scanned by them who ought rather admire; or if they list to try conjecture, he his fabric of the heavens left to their disputes, perhaps to move his laughter at their quaint opinions wide hereafter, when they come to model heaven calculate the stars, how they will wield the mighty frame, how build, unbuild, contrive to save appearances, how gird the sphere with centric and eccentric scribbled o’er, and epicycle, orb in orb.
Paradise Lost (1674, 1754), Book 8, 231.
I have always felt that astronomical hypotheses should not be regarded as articles of faith, but should only serve as a framework for astronomical calculations, so that it does not matter whether they were right or wrong, as long as the phenomena can be characterized precisely. For who could possibly be certain as to whether the uneven movement of the sun, if we follow the hypotheses of Ptolemy, can be explained by assuming an epicycle or eccentricity. Both assumptions are plausible. That’s why I would consider it quite desirable for you to tell something about that in the preface. In this way you would appease the Aristotelians and the theologians, whose opposition you dread.
From surviving fragment of a Letter (20 Apr 1541) answering a query from Copernicus as to whether he should publish his book (De Revolutionibus). From the German in Leopold Friedrich Prowe, Nicolaus Coppernicus (1883), Vol. 1, Part 2, 521-522. Translated from Prowe by Webmaster using web resources. Original German: “Hypothesen nicht als Glaubens-Artikel zu betrachten seien, sondern nur als Grundlage für die astronomischen Rechnungen zu dienen hätten, so dass es nicht darauf ankomme, ob sie richtig oder falsch seien, wofern sich nur die Erscheinungen dadurch genau bestimmen liessen. »Denn wer dürfte uns wohl darüber sichere Auskunft geben, ob die ungleiche Bewegung der Sonne, wenn wir den Hypothesen des Ptolemaeus folgen, durch Annahme eines Epicykels oder der Ekcentricität zu erklären sei. Beide Annahmen sind gestattet. Daher würde ich—so schliesst Osiander—es für recht wünschenswerth erachten, wenn Du hierüber in der Vorrede etwas beibrächtest. Auf diese Weise würdest Du die Aristoteliker und die Theologen milder stimmen, von denen Du befürchtest, dass sie heftigen Widerspruch kundthun werden.«” Compare Latin text, from Johannes Kepler, 'Apologia Tychonia', Astronomi Opera Omnia (1858), Vol. 1, 246: “De hypothesibus ego sic sensi semper, non esse articulos fidei, sed fundamenta calculi ita ut, etiamsi falsae sint, modo motuum φαινομενα exacte exhibeant, nihil referat; quis enim nos certiores reddet, an Solis inaequalis motus nomine epicycli an nomine eccentricitatis contingat, si Ptolemaei hypotheses sequamur, cum id possit utrumque. Quare plausibile fore videretur, si hac de re in praefatione nonnihil attingeres. Sic enim placidiores redderes peripatheticos et theologos, quos contradicturos metuis.”
The Greeks in the first vigour of their pursuit of mathematical truth, at the time of Plato and soon after, had by no means confined themselves to those propositions which had a visible bearing on the phenomena of nature; but had followed out many beautiful trains of research concerning various kinds of figures, for the sake of their beauty alone; as for instance in their doctrine of Conic Sections, of which curves they had discovered all the principal properties. But it is curious to remark, that these investigations, thus pursued at first as mere matters of curiosity and intellectual gratification, were destined, two thousand years later, to play a very important part in establishing that system of celestial motions which succeeded the Platonic scheme of cycles and epicycles. If the properties of conic sections had not been demonstrated by the Greeks and thus rendered familiar to the mathematicians of succeeding ages, Kepler would probably not have been able to discover those laws respecting the orbits and motions of planets which were the occasion of the greatest revolution that ever happened in the history of science.
In History of Scientific Ideas, Bk. 9, chap. 14, sect. 3.
Yet the widespread [planetary theories], advanced by Ptolemy and most other [astronomers], although consistent with the numerical [data], seemed likewise to present no small difficulty. For these theories were not adequate unless they also conceived certain equalizing circles, which made the planet appear to move at all times with uniform velocity neither on its deferent sphere nor about its own [epicycle's] center … Therefore, having become aware of these [defects], I often considered whether there could perhaps be found a more reasonable arrangement of circles, from which every apparent irregularity would be derived while everything in itself would move uniformly, as is required by the rule of perfect motion.
From Nicholaus Copernicus, Edward Rosen (trans.), Pawel Czartoryski (ed.) 'Commentariolus', in Nicholas Copernicus: Minor Works (1985), 81-83. Excerpted in Lisa M. Dolling, Arthur F. Gianelli and Glenn N. Statile (eds.) The Tests of Time: Readings in the Development of Physical Theory (2003), 40.
In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.
(1987) -- 
