Part 1 (1/2)
The gradual acceptance of the Copernican theory of the universe.
by Dorothy Stimson.
PREFACE
This study does not belong in the field of astronomy, but in that of the history of thought; for it is an endeavor to trace the changes in people's beliefs and conceptions in regard to the universe as these were wrought by the dissolution of superst.i.tion resulting from the scientific and rationalist movements. The opening chapter is intended to do no more than to review briefly the astronomical theories up to the age of Copernicus, in order to provide a background for the better comprehension of the work of Copernicus and its effects.
Such a study has been rendered possible only by the generous loan of rare books by Professor Herbert D. Foster of Dartmouth College, Professor Edwin E. Slosson of Columbia University, Doctor George A.
Plimpton and Major George Haven Putnam, both of New York, and especially by the kindly generosity of Professor David Eugene Smith of Teachers College who placed his unique collection of rare mathematical books at the writer's disposal and gave her many valuable suggestions as to available material. Professors James T. Shotwell and Harold Jacoby of Columbia University have read parts of this study in ma.n.u.script. The writer gratefully acknowledges her indebtedness not only to these gentlemen, but to the many others, librarians and their a.s.sistants, fellow-students and friends, too numerous to mention individually, whose ready interest and whose suggestions have been of real service, and above all to Professor James Harvey Robinson at whose suggestion and under whose guidance the work was undertaken, and to the Reverend Doctor Henry A. Stimson whose advice and criticism have been an unfailing source of help and encouragement.
PART ONE
AN HISTORICAL SKETCH OF THE HELIOCENTRIC THEORY OF THE UNIVERSE.
CHAPTER I.
THE DEVELOPMENT OF ASTRONOMICAL THOUGHT TO 1400 A.D.
_A Preliminary Sketch of Early Theories as a Background._
The appearances in the heavens have from earliest historic ages filled men with wonder and awe; then they gradually became a source of questioning, and thinkers sought for explanations of the daily and nightly phenomena of sun, moon and stars. Scientific astronomy, however, was an impossibility until an exact system of chronology was devised.[1] Meanwhile men puzzled over the shape of the earth, its position in the universe, what the stars were and why the positions of some s.h.i.+fted, and what those fiery comets were that now and again appeared and struck terror to their hearts.
[Footnote 1: The earliest observation Ptolemy uses is an Egyptian one of an eclipse occurring March 21, 721 B.C. (c.u.mont: 7). [In these references, the Roman numerals refer to the volume, the Arabic to the page, except as stated otherwise. The full t.i.tle is given in the bibliography at the back under the author's name.]]
In answer to such questions, the Chaldean thinkers, slightly before the rise of the Greek schools of philosophy, developed the idea of the seven heavens in their crystalline spheres encircling the earth as their center.[2] This conception seems to lie back of both the later Egyptian and Hebraic cosmologies, as well as of the Ptolemaic. Through the visits of Greek philosophers to Egyptian sh.o.r.es this conception helped to shape Greek thought and so indirectly affected western civilization. Thus our heritage in astronomical thought, as in many other lines, comes from the Greeks and the Romans reaching Europe (in part through Arabia and Spain), where it was shaped by the influence of the schools down to the close of the Middle Ages when men began anew to withstand authority in behalf of observation and were not afraid to follow whither their reason led them.
[Footnote 2: Warren: 40. See ”Calendar” in Hastings: _Ency. of Religion and Ethics_.]
But not all Greek philosophers, it seems,[3] either knew or accepted the Babylonian cosmology.[4] According to Plutarch, though Thales (640?-546? B.C.) and later the Stoics believed the earth to be spherical in form, Anaximander (610-546? B.C.) thought it to be like a ”smooth stony pillar,” Anaximenes (6th cent.) like a ”table.”
Beginning with the followers of Thales or perhaps Parmenides (?-500 B.C.), as Diogenes Laertius claims,[5] a long line of Greek thinkers including Plato (428?-347? B.C.) and Aristotle (384-322 B.C.) placed the earth in the center of the universe. Whether Plato held that the earth ”encircled” or ”clung” around the axis is a disputed point;[6]
but Aristotle claimed it was the fixed and immovable center around which swung the spherical universe with its heaven of fixed stars and its seven concentric circles of the planets kept in their places by their transparent crystalline spheres.[7]
[Footnote 3: For a summary of recent researches, see the preface of Heath: _Aristarchus of Samos_. For further details, see Heath: _Op.
cit._, and the writings of Kugler and Schiaparelli.]
[Footnote 4: See Plutarch: _Moralia: De placitas Philosophorum_, Lib.
I et II, (V. 264-277, 296-316).]
[Footnote 5: Diogenes Laertius: _De Vitis_, Lib. IX, c. 3 (252).]
[Footnote 6: Plato: _Timaeus_, sec. 39 (III, 459 in Jowett's translation).]
[Footnote 7: Aristotle: _De Mundo_, c. 2 et 6 (III, 628 and 636).]
The stars were an even greater problem. Anaximenes thought they were ”fastened like nails” in a crystalline firmament, and others thought them to be ”fiery plates of gold resembling pictures.”[8] But if the heavens were solid, how could the brief presence of a comet be explained?