Vincenzo De Risi Editor the Objects of Geometry from Antiquity to The

Total Page:16

File Type:pdf, Size:1020Kb

Vincenzo De Risi Editor the Objects of Geometry from Antiquity to The Trends in the History of Science Vincenzo De Risi Editor Mathematizing Space The Objects of Geometry from Antiquity to the Early Modern Age Trends in the History of Science Trends in the History of Science is a series devoted to the publication of volumes arising from workshops and conferences in all areas of current research in the history of science, primarily with a focus on the history of mathematics, physics, and their applications. Its aim is to make current developments available to the community as rapidly as possible without compromising quality, and to archive those developments for reference purposes. Proposals for volumes can be submitted using the online book project submission form at our website www.birkhauser- science.com. More information about this series at http://www.springer.com/series/11668 Vincenzo De Risi Editor Mathematizing Space The Objects of Geometry from Antiquity to the Early Modern Age Editor Vincenzo De Risi History of Science Max Planck Institute Berlin Germany ISSN 2297-2951 ISSN 2297-296X (electronic) Trends in the History of Science ISBN 978-3-319-12101-7 ISBN 978-3-319-12102-4 (eBook) DOI 10.1007/978-3-319-12102-4 Library of Congress Control Number: 2014957136 Springer Cham Heidelberg New York Dordrecht London © Springer International Publishing Switzerland 2015 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. Printed on acid-free paper Springer International Publishing AG Switzerland is part of Springer Science+Business Media (www.birkhauser-science.com) Foreword The present book collects the essays presented at the conference on Space, Geometry and the Imagination from Antiquity to the Early Modern Age, jointly organized by the Max Planck Institute for the History of Science (Berlin) and the Centro Matematico ‘Ennio De Giorgi’ of the Scuola Normale Superiore (Pisa), and hosted by the Max Planck Institute in August 27–29, 2012. The conference was part of the activities of the MPI Research Group on Modern Geometry and Space, directed by Vincenzo De Risi. The Group’s principal aim is to study the inter- connections between the history of geometry and the philosophy of space in the pre-Modern and Early Modern Age. In particular, several investigations of the fellows of the Research Group were directed toward understanding the complex epistemological revolution that transformed the classical geometry of figures into the modern geometry of space. The above-mentioned conference represented one of the high points of this research, and we are grateful to Birkhäuser for accepting to publish the proceedings of the meeting. We acknowledge the generous support of the two institutions, the Max Planck Institute and the Scuola Normale, for organizing the conference. We would par- ticularly like to thank the Director of the Centro ‘Ennio De Giorgi’ in Pisa, Mariano Giaquinta, whose early involvement in the organization was crucial for the reali- zation of the project. We are especially grateful to the distinguished scholars who took part in the conference and accepted to discuss their views with us on space and geometry, and for their willingness to contribute to the present volume. Their intellectual gener- osity made it possible for a real scientific exchange to take place that enlightened the workshop in Berlin and still shines in their written essays. We also thank all other participants in the conference, fellows of the Max Planck Institute, students, and visiting scholars, whose points of view and objections played an important part in enriching the discussion. We finally thank Chiara Fabbrizi and Fred Sengmueller for their help in editing the present volume. v Contents Introduction ........................................... 1 Vincenzo De Risi What’s Location Got to Do with It? Place, Space, and the Infinite in Classical Greek Mathematics ............................. 15 Henry Mendell A Note on Lines and Planes in Euclid’s Geometry ............... 65 Jeremy Gray Theon of Smyrna and Ptolemy on Celestial Modelling in Two and Three Dimensions .................................... 75 Alexander Jones Proclus’ Conception of Geometric Space and Its Actuality.......... 105 David Rabouin Subject, Space, Object: The Birth of Modernity ................. 143 Franco Farinelli On Natural Geometry and Seeing Distance Directly in Descartes ..... 157 Gary Hatfield Hobbes’s Theory of Space ................................. 193 Douglas Jesseph Mathematics and Infinity in Descartes and Newton ............... 209 Andrew Janiak vii viii Contents Leibniz’s Transcendental Aesthetic........................... 231 Daniel Garber Hume’s Skepticism and Inductivism Concerning Space and Geometry .......................................... 255 Graciela De Pierris Kant on Geometry and Experience........................... 275 Michael Friedman Index ................................................ 311 Contributors Graciela De Pierris Department of Philosophy, Stanford University, Stanford, CA, USA Vincenzo De Risi Max Planck Institute for the History of Science, Berlin, Germany Franco Farinelli Dipartimento di Filosofia e Comunicazione, Università di Bologna, Bologna, Italy Michael Friedman Department of Philosophy, Stanford University, Stanford, CA, USA Daniel Garber Department of Philosophy, Princeton University, Princeton, USA Jeremy Gray Department of Mathematics and Statistics, The Open University, Buckinghamshire, UK Gary Hatfield Department of Philosophy, University of Pennsylvania, Philadelphia, PA, USA Andrew Janiak Department of Philosophy, Duke University, Durham, NC, USA Douglas Jesseph Department of Philosophy, University of South Florida, Tampa, FL, USA Alexander Jones Institute for the Study of the Ancient World, New York University, New York, USA Henry Mendell Department of Philosophy, California State University, Los Angeles, CA, USA David Rabouin Université Paris 7—CNRS Laboratoire SPHERE UMR 7219, Paris Cedex 13, France ix Introduction Vincenzo De Risi Today the definition of geometry as the science of space is generally accepted by both epistemologists and mathematicians. The history of modern geometry is entirely built around the mathematical notion of space, and different approaches to this science, from Gauss’ studies of intrinsic curvature to the Erlangen Program, from the discovery of General Relativity to the most recent developments in topology (take, for instance, Thurston’s geometrization conjecture and its proof) rely on a general understanding of mathematical space that remains constant through different perspectives and offers a common ground for regarding all these developments as parts of a single enterprise. Modern geometry is simply incon- ceivable without the notion of space. Nonetheless, the definition of geometry as the science of space, however stan- dard, is properly speaking modern. Should we go through the thirteen books of Euclid’s Elements, or in fact the entire corpus of ancient mathematics, we would find almost no occurrence of spatial concepts or terms. Were we to follow the millennial development of Classical geometry in the Middle Ages or the Renais- sance, we would still not find any reference to space. The first (and quite rhetorical) mention of spatium in a geometrical essay does not predate the last decades of the sixteenth century. To see spatial notions effectively employed in geometrical rea- soning, we have to wait for another one hundred years. Leibniz’ work on geometry (the analysis situs) is probably the first attempt in this direction, and in any case it ushered in a general discussion about the object of geometrical investigation. The eighteenth century debated whether geometry had to be regarded as a science of space, and this new idea initially attracted more opponents than supporters; by the end of the century the spatial backers won their battle, and the nineteenth century V. De Risi (&) Max Planck Institute for the History of Science, Boltzmannstraße 22, 14195 Berlin, Germany e-mail: [email protected] © Springer International Publishing Switzerland 2015 1 V. De Risi (ed.), Mathematizing Space, Trends in the History of Science, DOI 10.1007/978-3-319-12102-4_1 2 V. De Risi declared that space was indeed the object of geometry. The mathematization of space was then complete: classical geometry came to an end and modern geometry was born. In fact, even though the divide between ancient and modern geometry may be arbitrarily demarcated into several historically distinct episodes (such as the birth of algebraic geometry or the discovery
Recommended publications
  • Basic Principles of Celestial Navigation James A
    Basic principles of celestial navigation James A. Van Allena) Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242 ͑Received 16 January 2004; accepted 10 June 2004͒ Celestial navigation is a technique for determining one’s geographic position by the observation of identified stars, identified planets, the Sun, and the Moon. This subject has a multitude of refinements which, although valuable to a professional navigator, tend to obscure the basic principles. I describe these principles, give an analytical solution of the classical two-star-sight problem without any dependence on prior knowledge of position, and include several examples. Some approximations and simplifications are made in the interest of clarity. © 2004 American Association of Physics Teachers. ͓DOI: 10.1119/1.1778391͔ I. INTRODUCTION longitude ⌳ is between 0° and 360°, although often it is convenient to take the longitude westward of the prime me- Celestial navigation is a technique for determining one’s ridian to be between 0° and Ϫ180°. The longitude of P also geographic position by the observation of identified stars, can be specified by the plane angle in the equatorial plane identified planets, the Sun, and the Moon. Its basic principles whose vertex is at O with one radial line through the point at are a combination of rudimentary astronomical knowledge 1–3 which the meridian through P intersects the equatorial plane and spherical trigonometry. and the other radial line through the point G at which the Anyone who has been on a ship that is remote from any prime meridian intersects the equatorial plane ͑see Fig.
    [Show full text]
  • Ramiz Daniz the Scientist Passed Ahead of Centuries – Nasiraddin Tusi
    Ramiz Daniz Ramiz Daniz The scientist passed ahead of centuries – Nasiraddin Tusi Baku -2013 Scientific editor – the Associate Member of ANAS, Professor 1 Ramiz Daniz Eybali Mehraliyev Preface – the Associate Member of ANAS, Professor Ramiz Mammadov Scientific editor – the Associate Member of ANAS, Doctor of physics and mathematics, Academician Eyyub Guliyev Reviewers – the Associate Member of ANAS, Professor Rehim Husseinov, Associate Member of ANAS, Professor Rafig Aliyev, Professor Ajdar Agayev, senior lecturer Vidadi Bashirov Literary editor – the philologist Ganira Amirjanova Computer design – Sevinj Computer operator – Sinay Translator - Hokume Hebibova Ramiz Daniz “The scientist passed ahead of centuries – Nasiraddin Tusi”. “MM-S”, 2013, 297 p İSBN 978-9952-8230-3-5 Writing about the remarkable Azerbaijani scientist Nasiraddin Tusi, who has a great scientific heritage, is very responsible and honorable. Nasiraddin Tusi, who has a very significant place in the world encyclopedia together with well-known phenomenal scientists, is one of the most honorary personalities of our nation. It may be named precious stone of the Academy of Sciences in the East. Nasiraddin Tusi has masterpieces about mathematics, geometry, astronomy, geography and ethics and he is an inventor of a lot of unique inventions and discoveries. According to the scientist, America had been discovered hundreds of years ago. Unfortunately, most peoples don’t know this fact. I want to inform readers about Tusi’s achievements by means of this work. D 4702060103 © R.Daniz 2013 M 087-2013 2 Ramiz Daniz I’m grateful to leaders of the State Oil Company of Azerbaijan Republic for their material and moral supports for publication of the work The book has been published in accordance with the order of the “Partner” Science Development Support Social Union with the grant of the State Oil Company of Azerbaijan Republic Courageous step towards the great purpose 3 Ramiz Daniz I’m editing new work of the young writer.
    [Show full text]
  • In. ^Ifil Fiegree in PNILOSOPNY
    ISLAMIC PHILOSOPHY OF SCIENCE: A CRITICAL STUDY O F HOSSAIN NASR Dis««rtation Submitted TO THE Aiigarh Muslim University, Aligarh for the a^ar d of in. ^Ifil fiegree IN PNILOSOPNY BY SHBIKH ARJBD Abl Under the Kind Supervision of PROF. S. WAHEED AKHTAR Cbiimwa, D«ptt. ol PhiloMphy. DEPARTMENT OF PHILOSOPHY ALIGARH IWIUSLIIM UNIVERSITY ALIGARH 1993 nmiH DS2464 gg®g@eg^^@@@g@@€'@@@@gl| " 0 3 9 H ^ ? S f I O ( D .'^ ••• ¥4 H ,. f f 3« K &^: 3 * 9 m H m «< K t c * - ft .1 D i f m e Q > i j 8"' r E > H I > 5 C I- 115m Vi\ ?- 2 S? 1 i' C £ O H Tl < ACKNOWLEDGEMENT In the name of Allah« the Merciful and the Compassionate. It gives me great pleasure to thanks my kind hearted supervisor Prof. S. Waheed Akhtar, Chairman, Department of Philosophy, who guided me to complete this work. In spite of his multifarious intellectual activities, he gave me valuable time and encouraged me from time to time for this work. Not only he is a philosopher but also a man of literature and sugge'sted me such kind of topic. Without his careful guidance this work could not be completed in proper time. I am indebted to my parents, SK Samser All and Mrs. AJema Khatun and also thankful to my uncle Dr. Sheikh Amjad Ali for encouraging me in research. I am also thankful to my teachers in the department of Philosophy, Dr. M. Rafique, Dr. Tasaduque Hussain, Mr. Naushad, Mr. Muquim and Dr. Sayed.
    [Show full text]
  • Ancient Astronomy
    3. The Science of Astronomy News: • Solar Observations due We especially need imagination in science. It is • Homework problems from Ch. 2 Due not all mathematics, nor all logic, but is • Sextant labs (due this week) somewhat beauty and poetry. • Test Next week on Thursday • Projects ideas Due 2.5 weeks Maria Mitchell (1818 – 1889) • For homework, do “Orbits and Kepler’s Astronomer and first woman Laws” tutorial, read Ch. 4 and S1.4 S1.5 by elected to American Academy of next week Arts & Sciences • Short SkyGazer tutorial 3.1 Everyday Science Scientific Thinking • It is a natural part of human behavior. • We draw conclusions based on our experiences. • Progress is made through “trial and error.” 3.2 The Ancient Roots of Science Ancient Astronomy • Many cultures throughout the world practiced astronomy. • They made careful observations of the sky. • Over a period of time, they would notice the cyclic motions of: – Sun – Moon – planets – celestial sphere (stars) 2 1 Mayans (fl. A.D. 400 – 1200) Stonehenge (completed 1550 BC) This famous structure in England was used as an observatory. • lived in central America • If you stand in the middle: • accurately predicted eclipses – the directions of sunrise & • Venus was very important sunset on the solstices is marked. • marked zenial passages – the directions of extreme moon the Observatory at C hic hén Itz á • Mayan mathematics rise & set are marked. – base 20 system • The Aubrey holes are believed to – invented the concept of “zero” be an analog eclipse computer. Anasazi (ca. A.D. 1000) • lived in “four corners” Plains Tribes of N.
    [Show full text]
  • The Impact of the Roman Army (200 BC – AD 476)
    Impact of Empire 6 IMEM-6-deBlois_CS2.indd i 5-4-2007 8:35:52 Impact of Empire Editorial Board of the series Impact of Empire (= Management Team of the Network Impact of Empire) Lukas de Blois, Angelos Chaniotis Ségolène Demougin, Olivier Hekster, Gerda de Kleijn Luuk de Ligt, Elio Lo Cascio, Michael Peachin John Rich, and Christian Witschel Executive Secretariat of the Series and the Network Lukas de Blois, Olivier Hekster Gerda de Kleijn and John Rich Radboud University of Nijmegen, Erasmusplein 1, P.O. Box 9103, 6500 HD Nijmegen, The Netherlands E-mail addresses: [email protected] and [email protected] Academic Board of the International Network Impact of Empire geza alföldy – stéphane benoist – anthony birley christer bruun – john drinkwater – werner eck – peter funke andrea giardina – johannes hahn – fik meijer – onno van nijf marie-thérèse raepsaet-charlier – john richardson bert van der spek – richard talbert – willem zwalve VOLUME 6 IMEM-6-deBlois_CS2.indd ii 5-4-2007 8:35:52 The Impact of the Roman Army (200 BC – AD 476) Economic, Social, Political, Religious and Cultural Aspects Proceedings of the Sixth Workshop of the International Network Impact of Empire (Roman Empire, 200 B.C. – A.D. 476) Capri, March 29 – April 2, 2005 Edited by Lukas de Blois & Elio Lo Cascio With the Aid of Olivier Hekster & Gerda de Kleijn LEIDEN • BOSTON 2007 This is an open access title distributed under the terms of the CC-BY-NC 4.0 License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
    [Show full text]
  • SEXTANT -‐ Sta2on Explorer for X-‐Ray Timing & Naviga2on Technology
    SEXTANT - Sta+on Explorer for X-ray Timing & Navigaon Technology Ronald J. Litchford, Ph.D., P.E. Principal Technologist NASA Space Technology Mission Directorate 593rd WE-Heraeus Seminar Physikzentrum Bad Honnef, DEU, JUNE 8-11, 2015 GSFC 1 • Millisecond Pulsar X-ray Navigaon (XNAV) – XNAV Concept & Development History – NICER/SEXTANT: Companion Science/Technology Missions • SEXTANT Mission Overview – ISS Flight Plaorm & Hardware – SEXTANT Mission ObjecQves • SEXTANT System Architecture – X-ray Timing Instrument (XTI) – Flight So`ware – Ground Testbed & End-to-End Simulaon – Ground System – CONOPS • Summary 2 • Millisecond Pulsar X-ray Navigaon – Pulsars are neutron stars that appear to pulsate across the electromagneQc spectrum, but are bright enough in X-rays to enable XNAV instrumentaon & soluQons – Some millisecond pulsars (MSPs) rival atomic clocks in long- term Qming stability – Pulse phase or Qme of arrival deviaons can update spacecra dynamics model along line of sight – Observing mulQple MSPs can yield 3D orbit data – GPS-like posiQoning & Qming throughout solar system & beyond -8 PSR B1937+21 (radio) -10 PSR B1855+09 (radio) -12 -14 PSR B1937+21 Log [Fractional Clock Stability]Log Baseline mission (NICER) -16 0.1 1 10 Time Interval (yr) NE2024 3 One column Two column • XNAV has rich history beginning with discovery of first radio pulsar – Significant body of published research • Naval Research Laboratory (NRL) (1999-2000) – UnconvenQonal Stellar Aspect (USA) Experiment • DARPA XNAV Project (2005-2006) – Ball Aerospace collaborated
    [Show full text]
  • Chama Newsletter
    INTERNATIONAL UNION OF HISTORY & PHILOSOPHY OF SCIENCE CHAMA NEWSLETTER Commission for History of Ancient and Medieval Astronomy Editors: S.M. Razaullah Ansari, Anne Tihon Vol. 7, No. 1, June 2009 Assistant Secretary: Laurence Tuerlinckx Website: http://chama.fltr.ucl.ac.be FOREWORD BY THE PRESIDENT C ONTENTS : I N T HIS N U M B E R Let me announce gladly that our page Foreword Commission’s Symposium (S-1) has been 1 successfully organised. 2 XXIII International Congress of We are publishing here its programme, which History of Science and Technology, consists of 15 talks, divided into two sessions. The Budapest, 28 July - 2 August 2009 first deals with “Ptolemy, His Writings and their 3 The CHAMA’s symposium in Transmission: Status of Present Research” and the Budapest second is on “Contextual Oriental Studies”. I 4 Astronomy and Mathematics in acknowledge here all speakers, who accepted our Ancient India: Report of the 11 th request to participate in this Symposium. Please note Belgian Indology Day. that each session is divided further into two sub- 6 Report of the International Scientific sessions due to the allotted time slot. The Conference on Mirza Ulughbeg Symposium will be held at the Venue of the 8 Obituary Congress in Room 7 on July 29 and 30 at the 9 New Books following times: 15:00-17:00, 17:30- 19:30. I look forward to meeting all of you in Budapest. Please 11 Periodicals ask your interested friends and colleagues also to attend. 12 Recent publications of the members of CHAMA I may add that the third circular of the Congress is available on its website.
    [Show full text]
  • The Impact of the Roman Republican Army
    PART ONE THE IMPACT OF THE ROMAN REPUBLICAN ARMY Luuk De Ligt - 9789047430391 Downloaded from Brill.com09/28/2021 03:05:09AM via free access ROMAN MANPOWER RESOURCES AND THE PROLETARIANIZATION OF THE ROMAN ARMY IN THE SECOND CENTURY BC Luuk De Ligt Demographic developments In his account of the run-up to the passing of the lex Sempronia agraria of 133 bc Appian repeatedly underlines the military and demographic rationale of the Gracchan land reforms. In chapter 8, for instance, he describes Tiberius Gracchus as making a powerful speech in which the people of Italy (Italiotai) were characterized as excellent ghters but also as declining into poverty and depopulation. Similarly, Tiberius Gracchus is said to have defended his proposal by rhetorically asking whether a citizen was not always a better man than a slave, and a soldier more useful than a non-soldier. The same demographic and military theme is found also in Appian’s description of the undoing of the Gracchan reform programme, as a result of which ‘the numbers of both citizens and soldiers diminished still more’.1 At rst sight the census gures for the period 163–130 bc seem to tell a similar story: whereas the censors of 164/3 bc were able to reg- ister some 337,000 adult male citizens, the census gure for 130 bc is only 319,000. Although a decrease of less than 20,000 in more than three decades may not seem huge, the general trend for these years is in sharp contrast to the steep increase indicated by the census gures for the rst 35 years of the second century bc.
    [Show full text]
  • Encyclopedia of the History of Arabic Science. Volume 2, Mathematics
    Encyclopedia of the History of Arabic Science Encyclopedia of the History of Arabic Science Volume 2 Edited by ROSHDI RASHED in collaboration with RÉGIS MORELON LONDON AND NEW YORK First published in 1996 by Routledge 11 New Fetter Lane, London EC4P 4EE 29 West 35th Street, New York, NY 10001 This edition published in the Taylor & Francis e-Library, 2009. To purchase your own copy of this or any of Taylor & Francis or Routledge’s collection of thousands of eBooks please go to www.eBookstore.tandf.co.uk. Structure and editorial matter © 1996 Routledge The chapters © 1996 Routledge All rights reserved. No part of this book may be reprinted or reproduced or utilized in any form or by any electronic, mechanical or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library. Library of Congress Cataloguing-in-Publication Data A catalogue record for this book is available on request. ISBN 0-203-40360-6 Master e-book ISBN ISBN 0-203-71184-X (Adobe ebook Reader Format) ISBN 0-415-12411-5 (Print Edition) 3 volume set ISBN 0-415-02063-8 Contents VOLUME 1 Contents v Preface ix 1 General survey of Arabic astronomy Régis Morelon 1 2 Eastern Arabic astronomy between the eighth and the eleventh centuries 20 Régis Morelon 3 Arabic planetary theories after the eleventh century AD 58 George Saliba 4 Astronomy and
    [Show full text]
  • (IOWP) Arabs in Late First Millennium BC Babylonia
    Imperium and Officium Working Papers (IOWP) Arabs in late first millennium BC Babylonia Version 00 April 2014 Reinhard Pirngruber (University of Vienna, Department of Oriental Studies) Abstract: This brief article discusses and aims to contextualize the references to Arabs in the corpus of the Astronomical Diaries. © Reinhard Pirngruber 2014 [email protected] Reinhard Pirngruber 1 Arabs in late first millennium BC Babylonia1 Introduction Throughout the first millennium BC, the large entities reigning over Mesopotamia – the native Neo-Assyrian and Neo-Babylonian Empires as well as the subsequent foreign, Iranian and Graeco-Macedonian respectively, rulers of the Achaemenid, Seleucid and Parthian dynasties – were in frequent contact with a people called “Arabs”, designated in the Akkadian language by means of the nisbah lúArbāya. The earliest attestation of this ethnonym in the cuneiform sources dates to the year 853 BC, when the so-called Kurkh-monolith, a victory stela of the Neo-Assyrian king Shalmaneser III commemorating his success in the battle at Qarqar on the Orontes river, mentions the “1,000 camels of the Gindibu’ the Arab” reinforcing a coalition of several local rulers headed by Ahab of Israel and Hadad-ezer of Damascus. The following two centuries of the Neo-Assyrian Empire until its demise early in the second half of the 7th century BC are then the most abundantly documented era in Ancient Near Eastern History as regards Arabs. Arab tribal leaders often occur in royal inscriptions as victims of the expansionist ambitions of the Neo-Assyrian kings, bearing tribute and swearing oaths of loyalty, whereas epistolographic sources document the efforts of Assyrian administrators in Syria of coming to terms with nomadic Arab tribal elements within the empire.
    [Show full text]
  • Navigation: the Mariner's Quadrant
    Navigation: The Mariner's Quadrant The quadrant is a very simple tool that allows the user to determine his or her latitude by measuring the altitude of a heavenly body. When used in celestial navigation or astronomy, altitude means the angle of elevation between the horizon and celestial bodies like the sun, planets, moon, or stars. The quadrant takes it name from its shape, which is a quarter of a circle. Invented by the Greeks around 240 B.C., several different types of quadrants have been used over the past 2500 years. Early quadrants used a 90 degree arc and a string Quadrants were often designed for bob to determine the angle of elevation to the sun, Polaris, and other celestial bodies. a specific use. Artillery officers used a simplified quadrant known as a gunner’s quadrant for aiming their guns and measuring distance. Astronomers used a far more complicated version of the quadrant that was engraved with geometrical and square lines showing the sun's path through the signs of the zodiac. Although average seamen would not have had much use for the complicated quadrants used by astronomers, they found that a simplified version was very useful for determining their latitude at sea. Cut from a piece of metal plate or wood, the mariner’s quadrant had a radius of about 6-8 inches. It had a pair of rectangular plates with pinhole sights on one of the straight edges for sighting. The only scale needed was the degree marks on the curved edge. It was light and easy to handle.
    [Show full text]
  • Ulugh Beg: Muḥammad Ṭaraghāy Ibn Shāhrukh Ibn Tīmūr
    From: Thomas Hockey et al. (eds.). The Biographical Encyclopedia of Astronomers, Springer Reference. New York: Springer, 2007, pp. 1157-1159 Courtesy of http://dx.doi.org/10.1007/978-0-387-30400-7_1401 Ulugh Beg: Muḥammad Ṭaraghāy ibn Shāhrukh ibn Tīmūr Benno van Dalen Born Sulṭāniyya, (Iran), 22 March 1394 Died near Samarqand, (Uzbekistan), 27 October 1449 Ulugh Beg (Turkish for “great prince”) was governor of Transoxiana and Turkestan and, during the last 2 years of his life, Timurid Sultan. However, he is mostly remembered as a patron of mathematics and astronomy. In Samarqand, he founded a school and the famous astronomical observatory, where the most extensive observations of planets and fixed stars at any Islamic observatory were made. Ulugh Beg is associated with a Persian astronomical handbook (zīj) that stands out for the accuracy with which its tables were computed. Ulugh Beg was the first‐born son of Shāhrukh (youngest son of the infamous conqueror Tīmūr or Tamerlane) and his first wife Gawharshād. He was raised at the court of his grandfather and, at the age of 10, was married to his cousin Agha Bīkī, whose mother was a direct descendent of Chingiz Khan. Thus Ulugh Beg could use the epithet Gūrgān, “royal son‐in‐law,” which had originally been used for Chingiz's son‐in‐law. In the years after Tīmūr's death in 1405, Ulugh Beg became governor of Turkestan and Transoxiana, the most important cities of which were the cultural centers Samarqand and Bukhara. Although not completely divorced from affairs of state, he is better known for his interest in religion, architecture, arts, and sciences, which were fostered by the Mongols as well as by the Timurids.
    [Show full text]