Studies in the History of Mathematics and Physical Sciences

Transcription

1 Studies in the History of Mathematics and Physical Sciences 11 Editor G. J. Toomer Advisory Board R. P. Boas P. J. Davis T. Hawkins M. J. Klein A. E. Shapiro D. Whiteside

2 "r" I.'... '11 f...,.. ~ , ri~~llrc.j('.la.fa.6rk'9uc. Jdarbaic~lc (i.:'.f..."-.7 ':f..\... 'J.l. /f.i:, ''''. f../.. f. "./.. /..1, -: ~ I.. r :' -,f\.. t A [.,." L. /.""1' 1-0 ~ r 11 ~ I!I ~t. lfl.l;' Q! (C lll'. ~1"c. J..",I" 1 l' 1 1/~ C~lI"Il" L~ "',111..:,1" '..'11 l.,/,,,1'.. J').. ~tu I.. 'UI'.. I.,... ~" T\-r<1I I'-IU It:.'II'' '.''.''I Ef J', Bibliotheque Nationale, Paris, MS fran<;ais 150, folio 16: Les Premieres Euvres de Jacques de Vaulx, pillote en La marine, au Havre (1583). In this navigational manual, we are shown a Jacob Staff, an astronomical instrument invented by Levi ben Gerson, and a method for graduating it. (Phot. Bib!. Nat., Paris.)

3 Bernard R. Goldstein The Astronomy of Levi ben Gerson ( ) A Critical Edition of Chapters 1-20 with Translation and Commentary With 68 Figures Springer-Verlag New York Berlin Heidelberg Tokyo

4 Bernard R. Goldstein Jewish Studies Program University of Pittsburgh 2604 Cathedral of Learning Pittsburgh, PA U.S.A. AMS Classification: 01A30, 01A35, Library of Congress Cataloging in Publication Data Goldstein, Bernard R. The astronomy of Levi ben Gerson. (Studies in the history of mathematics and physical sciences; 11) Bibliography: p. Includes index. 1. Astronomy-Early works to Astronomy, Jewish. 3. Levi ben Gershom, I. Title. II. Series. QB4l.G /.92/ by Springer-Verlag New York Inc. Softcover reprint of the hardcover 1st edition 1985 All rights reserved. No part of this book may be translated or reproduced in any form without written permission from Springer-Verlag, 175 Fifth Avenue, New York, New York 10010, U.S.A. Typeset by Asco Trade Typesetting Ltd., Hong Kong ISBN-13: DOl: / e-isbn-13:

5 To O. Neugebauer My teacher, friend, and guide

6 Preface It would seem that S. Munk was the first modern scholar to draw attention to the significance of Levi ben Gerson's Astronomy, surely the most original work on astronomy written in Hebrew in the Middle Ages. Munk (1859, p. 500) called for a specialist to undertake a serious study of this work, but there was little response to his plea in the succeeding century. Indeed, this is the first edition of the Hebrew text of any part of Levi's Astronomy but for the table of contents (Renan, 1893, pp ), and the poems celebrating the invention of the Jacob Staff that appear in chapter 9 (Carlebach, 191Oa, pp ). The text of Levi's Astronomy is written in a ponderous Hebrew style but the content sparkles with originality. The Ptolemaic tradition is subjected to a profound critique based on the idea that the planetary models must conform both to Levi's own observations as well as those of the ancients, and the claim that astronomical theory must be philosophically sound. The enduring vigor of the Ptolemaic tradition has been characterized by O. Neugebauer as follows: "There is no better way to convince oneself of the inner coherence of ancient and medieval astronomy than to place side by side the Almagest, al BaWini's Opus astronomicum and Copernicus's De Revolutionibus. Chapter by chapter, theorem by theorem, table by table, these works run parallel" (1957, pp ). It is surprising, therefore, to find that Levi departs from this well-trodden path, and opens his magnum opus with a discussion of instruments he himself invented, of models not previously considered, and of observations to test the theories presented. In addition to the Jacob Staff and the camera obscura, Levi describes a new instrument for finding the Moon's elongation from the Sun (chapter 10) and a modification of the astrolabe for purposes of observation (chapter 12). Levi tells us that his Astronomy was completed in 1328, but it has long been noted that observations made as late as 1340 are included in it. The text is quite long (over 250 folios) and so it seemed appropriate to publish a part of it, with others to come. Indeed, my own study of it began in 1968 and the

7 viii The Astronomy of Levi ben Gerson fruits of this research have appeared in a series of publications beginning in Among aspects of Levi's work that do not appear in the first 20 chapters are his analysis of precession (Goldstein, 1975), his solar and lunar tables (Goldstein, 1974a), his observations and analyses of solar and lunar eclipses (Goldstein, 1979), his lunar models (Goldstein, 1974a, pp ; 1974b), his views on cosmic distances (Goldstein, 1969a), and his criticisms of al-bitnlji (Goldstein, 1971, vol. 1, pp ). His planetary theories that are introduced beginning in chapter 21, and the observations on which they are based, remain to be analyzed, a difficult task because of lacunae that afflict all the manuscripts (both in the original Hebrew and in the medieval Latin translation). In the Introduction an attempt is made to place Levi in the astronomical tradition. Since he mentions few of his predecessors and none of his contemporaries, considerable uncertainty remains. It is equally difficult to assess his influence on subsequent generations of astronomers, for references to Levi are rare both in Hebrew and Latin, and one is often forced to rely on indirect evidence. Parts of this edition have been adapted from previous publications and appear here in revised form (Goldstein, 1974a, 1977, 1980). In order to facilitate references to the text, sentence numbers have been added, and they are used in the translation and the commentary as well as in the critical apparatus. The Latin translation has not been consulted systematically; it seems to be a quite literal rendering of the Hebrew. It is a pleasure to thank the institutions that have supported this research in various ways over the years: Yale University, The Hebrew University, Brown University, University of Pittsburgh, The Institute for Advanced Study (Princeton), Centre national de la recherche scientifique, Observatoire de Paris, The Museum for History of Science (Oxford), Istituto e Museo di Storia della Scienza (Florence), The American Philosophical Society, The American Council of Learned Societies, The John Simon Guggenheim Memorial Foundation, The National Science Foundation, and The National Endowment for the Humanities. The cooperation of librarians in many countries was kindly forthcoming, and I am especially grateful to M. Garel (Bibliotheque Nationale, Paris), M. Schmelzer (The Jewish Theological Seminary of America, New York), and B. Richler (National Library, Jerusalem). Numerous colleagues have assisted in this research and their suggestions have always been welcome. In particular, I wish to thank G. Beaujouan, B. Blumenkranz, J. Lay, G. Nahon, E. Poulle, R. Rashed, and J.-P. Verdet (Paris); F. Maddison and J. Roche (Oxford); R. Scheindlin and N. Siraisi (New York); P. Galluzzi (Florence); and A. Aaboe (New Haven). A special debt of thanks is due to G. J. Toomer, the editor of this series, for his careful

8 Preface IX reading of the completed draft of this book, and his many detailed and illuminating comments. Photographs appear courtesy of the Bibliotheque Nationale, the Adler Planetarium (Chicago), and the Istituto e Museo di Storia della Scienza (Florence). The Hebrew text was typed by Mrs. Karen Rosenzweig whose assistance is gratefully acknowledged. Paris December 1984 Bernard R. Goldstein

9 Manuscript Sigla N. Naples, Biblioteca Nazionale, heb. III F.9 (undated), with marginal notes by Mordecai Finzi (not in his hand). P. Paris, Bibliotheque Nationale, heb. 724 (dated 1397). Q. Paris, Bibliotheque Nationale, heb. 725 (dated 1510). For more information on the Hebrew and Latin manuscripts of Levi ben Gerson's Astronomy, see Goldstein, 1974a, pp ; and Goldstein, 1981, p.250. Notation Paragraphs, sentences, and sentence numbers in the text have been added by the editor. Sentence numbers and folio numbers for all three manuscripts may be found in the margin of the edited text: a vertical stroke in the text indicates the place where a new folio begins. The supplementary pagination for the Hebrew text appears inside square brackets. In the translation sentence numbers appear in square brackets, and in the commentary they are preceded by the symbol. Moreover, words added by the editor to facilitate reading the translation have been put inside square brackets.

10 Contents Preface Manuscript Sigla and Notation Introduction Translation Commentary References Index Hebrew Text VB X