DESARGUES' THEOREM Two Triangles ABC and a B C Are Said To
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Letter from Descartes to Desargues 1 (19 June 1639)
Appendix 1 Letter from Descartes to Desargues 1 (19 June 1639) Sir, The openness I have observed in your temperament, and my obligations to you, invite me to write to you freely what I can conjecture of the Treatise on Conic Sections, of which the R[everend] F[ather] M[ersenne] sent me the Draft. 2 You may have two designs, which are very good and very praiseworthy, but which do not both require the same course of action. One is to write for the learned, and to instruct them about some new properties of conics with which they are not yet familiar; the other is to write for people who are interested but not learned, and make this subject, which until now has been understood by very few people, but which is nevertheless very useful for Perspective, Architecture etc., accessible to the common people and easily understood by anyone who studies it from your book. If you have the first of these designs, it does not seem to me that you have any need to use new terms: for the learned, being already accustomed to the terms used by Apollonius, will not easily exchange them for others, even better ones, and thus your terms will only have the effect of making your proofs more difficult for them and discourage them from reading them. If you have the second design, your terms, being French, and showing wit and elegance in their invention, will certainly be better received than those of the Ancients by people who have no preconceived ideas; and they might even serve to attract some people to read your work, as they read works on Heraldry, Hunting, Architecture etc., without any wish to become hunters or architects but only to learn to talk about them correctly. -
Binomial Partial Steiner Triple Systems Containing Complete Graphs
Graphs and Combinatorics DOI 10.1007/s00373-016-1681-3 ORIGINAL PAPER Binomial partial Steiner triple systems containing complete graphs Małgorzata Pra˙zmowska1 · Krzysztof Pra˙zmowski2 Received: 1 December 2014 / Revised: 25 January 2016 © The Author(s) 2016. This article is published with open access at Springerlink.com Abstract We propose a new approach to studies on partial Steiner triple systems con- sisting in determining complete graphs contained in them. We establish the structure which complete graphs yield in a minimal PSTS that contains them. As a by-product we introduce the notion of a binomial PSTS as a configuration with parameters of a minimal PSTS with a complete subgraph. A representation of binomial PSTS with at least a given number of its maximal complete subgraphs is given in terms of systems of perspectives. Finally, we prove that for each admissible integer there is a binomial PSTS with this number of maximal complete subgraphs. Keywords Binomial configuration · Generalized Desargues configuration · Complete graph Mathematics Subject Classification 05B30 · 05C51 · 05B40 1 Introduction In the paper we investigate the structure which (may) yield complete graphs contained in a (partial) Steiner triple system (in short: in a PSTS). Our problem is, in fact, a particular instance of a general question, investigated in the literature, which STS’s B Małgorzata Pra˙zmowska [email protected] Krzysztof Pra˙zmowski [email protected] 1 Faculty of Mathematics and Informatics, University of Białystok, ul. Ciołkowskiego 1M, 15-245 Białystok, Poland 2 Institute of Mathematics, University of Białystok, ul. Ciołkowskiego 1M, 15-245 Białystok, Poland 123 Graphs and Combinatorics (more generally: which PSTS’s) contain/do not contain a configuration of a prescribed type. -
COMBINATORICS, Volume
http://dx.doi.org/10.1090/pspum/019 PROCEEDINGS OF SYMPOSIA IN PURE MATHEMATICS Volume XIX COMBINATORICS AMERICAN MATHEMATICAL SOCIETY Providence, Rhode Island 1971 Proceedings of the Symposium in Pure Mathematics of the American Mathematical Society Held at the University of California Los Angeles, California March 21-22, 1968 Prepared by the American Mathematical Society under National Science Foundation Grant GP-8436 Edited by Theodore S. Motzkin AMS 1970 Subject Classifications Primary 05Axx, 05Bxx, 05Cxx, 10-XX, 15-XX, 50-XX Secondary 04A20, 05A05, 05A17, 05A20, 05B05, 05B15, 05B20, 05B25, 05B30, 05C15, 05C99, 06A05, 10A45, 10C05, 14-XX, 20Bxx, 20Fxx, 50A20, 55C05, 55J05, 94A20 International Standard Book Number 0-8218-1419-2 Library of Congress Catalog Number 74-153879 Copyright © 1971 by the American Mathematical Society Printed in the United States of America All rights reserved except those granted to the United States Government May not be produced in any form without permission of the publishers Leo Moser (1921-1970) was active and productive in various aspects of combin• atorics and of its applications to number theory. He was in close contact with those with whom he had common interests: we will remember his sparkling wit, the universality of his anecdotes, and his stimulating presence. This volume, much of whose content he had enjoyed and appreciated, and which contains the re• construction of a contribution by him, is dedicated to his memory. CONTENTS Preface vii Modular Forms on Noncongruence Subgroups BY A. O. L. ATKIN AND H. P. F. SWINNERTON-DYER 1 Selfconjugate Tetrahedra with Respect to the Hermitian Variety xl+xl + *l + ;cg = 0 in PG(3, 22) and a Representation of PG(3, 3) BY R. -
Desargues, Girard
GIRARD DESARGUES (February 21, 1591 – October 1661) by HEINZ KLAUS STRICK, Germany GIRARD DESARGUES came from very wealthy families of lawyers and judges who worked at the Parlement, the highest appellate courts of France in Paris and Lyon. Nothing is known about GIRARD's youth, but it is safe to assume that he and his five siblings received the best possible education. While his two older brothers were admitted to the Parisian Parlement, he was involved in the silk trade in Lyon, as can be seen from a document dating from 1621. In 1626, after a journey through Flanders, he applied to the Paris city council for a licence to drill a well and use the water from the well. His idea was to construct an effective hydraulic pump to supply water to entire districts, but this project did not seem to be successful. After the death of his two older brothers in 1628, he took over the family inheritance and settled in Paris. There he met MARIN MERSENNE and soon became a member of his Academia Parisiensis, a discussion group of scientists including RENÉ DESCARTES, GILLES PERSONNE DE ROBERVAL, ÉTIENNE PASCAL and his son BLAISE. (drawing: © Andreas Strick) The first publication by DESARGUES to attract attention was Une méthode aisée pour apprendre et enseigner à lire et escrire la musique (An easy way to learn and teach to read and write music). In 1634 MERSENNE mentioned in a letter to his acquaintances that DESARGUES was working on a paper on perspective (projection from a point). But it was not until two years later that the work was published: only 12 pages long and in a small edition. -
Second Edition Volume I
Second Edition Thomas Beth Universitat¨ Karlsruhe Dieter Jungnickel Universitat¨ Augsburg Hanfried Lenz Freie Universitat¨ Berlin Volume I PUBLISHED BY THE PRESS SYNDICATE OF THE UNIVERSITY OF CAMBRIDGE The Pitt Building, Trumpington Street, Cambridge, United Kingdom CAMBRIDGE UNIVERSITY PRESS The Edinburgh Building, Cambridge CB2 2RU, UK www.cup.cam.ac.uk 40 West 20th Street, New York, NY 10011-4211, USA www.cup.org 10 Stamford Road, Oakleigh, Melbourne 3166, Australia Ruiz de Alarc´on 13, 28014 Madrid, Spain First edition c Bibliographisches Institut, Zurich, 1985 c Cambridge University Press, 1993 Second edition c Cambridge University Press, 1999 This book is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published 1999 Printed in the United Kingdom at the University Press, Cambridge Typeset in Times Roman 10/13pt. in LATEX2ε[TB] A catalogue record for this book is available from the British Library Library of Congress Cataloguing in Publication data Beth, Thomas, 1949– Design theory / Thomas Beth, Dieter Jungnickel, Hanfried Lenz. – 2nd ed. p. cm. Includes bibliographical references and index. ISBN 0 521 44432 2 (hardbound) 1. Combinatorial designs and configurations. I. Jungnickel, D. (Dieter), 1952– . II. Lenz, Hanfried. III. Title. QA166.25.B47 1999 5110.6 – dc21 98-29508 CIP ISBN 0 521 44432 2 hardback Contents I. Examples and basic definitions .................... 1 §1. Incidence structures and incidence matrices ............ 1 §2. Block designs and examples from affine and projective geometry ........................6 §3. t-designs, Steiner systems and configurations ......... -
1 H-France Forum Volume 14 (2019), Issue 4, #3 Jeffrey N. Peters, The
1 H-France Forum Volume 14 (2019), Issue 4, #3 Jeffrey N. Peters, The Written World. Space, Literature, and the Chorological Imagination in Early Modern France. Evanston: Northwestern University Press, 2018. vii + 272 pp. Figures, notes, and Copyright index. $34.95 (pb). ISBN 978-0-8101-3697-7; $99.95 (cl). ISBN 978-0- 8101-3698-4; $34.95 (Kindle). ISBN 978-0-8101-3699-1. Review Essay by David L. Sedley, Haverford College The Written World has on its cover an image from La Manière universelle de M. Desargues, pour pratiquer la perspective (1648). This book, written and illustrated by Abraham Bosse and based on the projective geometry of Girard Desargues, extends the theories of perspective codified by Leon Battista Alberti and his followers. [1] Alberti directed painters to pose a central point at the apparent conjunction of parallel lines in order to lend depth and coherence to their compositions. Desargues reinterpreted and renamed Alberti’s central point (and other points like it) as a point at infinity. Consequently, the convergent lines of a visual representation could be taken to indicate the infinite more emphatically than before. As an illustration of the art of putting objects in a perspective that emphasizes their connection to infinity, Bosse’s image suits Peters’ book to a T. Peters represents his objects of study—mainly a series of works of seventeenth-century French literature—with an eye to showing their affinity with the infinite. He frequently discusses infinity through chora, the Ancient Greek term used by Plato and adopted by Jacques Derrida to denote the space underlying all finite places and place- based thought. -
Mathematics and Arts
Mathematics and Arts All´egoriede la G´eom´etrie A mathematical interpretation Alda Carvalho, Carlos Pereira dos Santos, Jorge Nuno Silva ISEL & Cemapre-ISEG, CEAFEL-UL, University of Lisbon [email protected] [email protected] [email protected] Abstract: In this work, we present a mathematical interpretation for the mas- terpiece All´egoriede la G´eom´etrie (1649), painted by the French baroque artist Laurent de La Hyre (1606{1656). Keywords: Laurent de La Hyre, \All´egoriede la G´eom´etrie",baroque art, mathematical interpretation, perspective. Introduction The main purpose of this text is to present a mathematical interpretation for the masterpiece All´egoriede la G´eom´etrie, from a well-known series of paint- ings, Les 7 arts lib´eraux, by the French baroque artist Laurent de La Hyre (1606{1656). Figure 1: All´egoriede la G´eom´etrie (1649), oil on canvas. Recreational Mathematics Magazine, Number 5, pp. 33{45 DOI 10.1515/rmm{2016{0003 34 allegorie´ de la geom´ etrie´ Laurent de La Hyre painted the series Les 7 arts lib´eraux between 1649 and 1650 to decorate G´ed´eonTallemant's residence. Tallemant was an adviser of Louis xiv (1638{1715). The king was 10 years old at the time of the commission. According to the artist's son, Philippe de La Hire (1640{1718), writing around 1690 [5], (. .) une maison qui appartenoit autrefois a M. Tallemant, maistre des requestes, sept tableaux repres´entant les sept arts liberaux qui font l'ornement d'une chambre. Also, Guillet de Saint-Georges, a historiographer of the Acad´emieRoyale de Peinture et de Sculpture, mentioned that it was Laurent's work for the Ca- puchin church in the Marais which led to the commission for the \Seven Liberal Arts" in a house [2]. -
PAINTING and PERSPECTIVE 127 the Real World, That the Universe Is Ordered and Explicable Rationally in Terms of Geometry
PAINTING AND PERSPECTIVE 127 the real world, that the universe is ordered and explicable rationally in terms of geometry. Hence, like the Greek philosopher, he be lieved that to penetrate to the underlying significance, that is, the reality of the theme that he sought to display on canvas, he must reduce it to its mathematical content. Very interesting evidence of x the artist's attempt to discover the mathematical essence of his sub ject is found in one of Leonardo's studies in proportion. In it he Painting and Perspective tried to fit the structure of the ideal man to the ideal figures, the flquare and circle (plate VI). The sheer utility of mathematics for accurate description and the The world's the book where the eternal sense philosophy that mathematics is the essence of reality are only two Wrote his own thoughts; the living temple where, Painting his very self, with figures fair of the reasons why the Renaissance artist sought to use mathematics. He filled the whole immense circumference. There was another reason. The artist of the late medieval period and T. CAMPANELLA the Renaissance was, also, the architect and engineer of his day and so was necessarily mathematically inclined. Businessmen, secular princes, and ecclesiastical officials assigned all construction problems During the Middle Ages painting, serving somewhat as the hand to the artist. He designed and built churches, hospitals, palaces, maiden of the Church, concentrated on embellishing the thoughts cloisters, bridges, fortresses, dams, canals, town walls, and doctrines of Christianity. Toward the end of this period, the and instru ments of warfare. -
A Tale of the Cycloid in Four Acts
A Tale of the Cycloid In Four Acts Carlo Margio Figure 1: A point on a wheel tracing a cycloid, from a work by Pascal in 16589. Introduction In the words of Mersenne, a cycloid is “the curve traced in space by a point on a carriage wheel as it revolves, moving forward on the street surface.” 1 This deceptively simple curve has a large number of remarkable and unique properties from an integral ratio of its length to the radius of the generating circle, and an integral ratio of its enclosed area to the area of the generating circle, as can be proven using geometry or basic calculus, to the advanced and unique tautochrone and brachistochrone properties, that are best shown using the calculus of variations. Thrown in to this assortment, a cycloid is the only curve that is its own involute. Study of the cycloid can reinforce the curriculum concepts of curve parameterisation, length of a curve, and the area under a parametric curve. Being mechanically generated, the cycloid also lends itself to practical demonstrations that help visualise these abstract concepts. The history of the curve is as enthralling as the mathematics, and involves many of the great European mathematicians of the seventeenth century (See Appendix I “Mathematicians and Timeline”). Introducing the cycloid through the persons involved in its discovery, and the struggles they underwent to get credit for their insights, not only gives sequence and order to the cycloid’s properties and shows which properties required advances in mathematics, but it also gives a human face to the mathematicians involved and makes them seem less remote, despite their, at times, seemingly superhuman discoveries. -
Projective Geometry Seen in Renaissance Art
Projective Geometry Seen in Renaissance Art Word Count: 2655 Emily Markowsky ID: 112235642 December 7th, 2020 Abstract: For the West, the Renaissance was a revival of long-forgotten knowledge from classical antiquity. The use of geometric techniques from Greek mathematics led to the development of linear perspective as an artistic technique, a method for projecting three dimensional figures onto a two dimensional plane, i.e. the painting itself. An “image plane” intersects the observer’s line of sight to an object, projecting this point onto the intersection point in the image plane. This method is more mathematically interesting than it seems; we can formalize the notion of a vanishing point as a “point at infinity,” from which the subject of projective geometry was born. This paper outlines the historical process of this development and discusses its mathematical implications, including a proof of Desargues’ Theorem of projective geometry. Outline: I. Introduction A. Historical context; the Middle Ages and medieval art B. How linear perspective contributes to the realism of Renaissance art, incl. a comparison between similar pieces from each period. C. Influence of Euclid II. Geometry of Vision and Projection A. Euclid’s Optics B. Cone of vision and the use of conic sections to model projection of an object onto a picture. Projection of a circle explained intuitively. C. Brunelleschi’s experiments and the invention of his technique for linear perspective D. Notion of points at infinity as a vanishing point III. Projective geometry and Desargues’ Theorem A. Definition of a projective plane and relation to earlier concepts discussed B. -
Graph Theory Graph Theory (II)
J.A. Bondy U.S.R. Murty Graph Theory (II) ABC J.A. Bondy, PhD U.S.R. Murty, PhD Universite´ Claude-Bernard Lyon 1 Mathematics Faculty Domaine de Gerland University of Waterloo 50 Avenue Tony Garnier 200 University Avenue West 69366 Lyon Cedex 07 Waterloo, Ontario, Canada France N2L 3G1 Editorial Board S. Axler K.A. Ribet Mathematics Department Mathematics Department San Francisco State University University of California, Berkeley San Francisco, CA 94132 Berkeley, CA 94720-3840 USA USA Graduate Texts in Mathematics series ISSN: 0072-5285 ISBN: 978-1-84628-969-9 e-ISBN: 978-1-84628-970-5 DOI: 10.1007/978-1-84628-970-5 Library of Congress Control Number: 2007940370 Mathematics Subject Classification (2000): 05C; 68R10 °c J.A. Bondy & U.S.R. Murty 2008 Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or trans- mitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms of licenses issued by the Copyright Licensing Agency. Enquiries concerning reproduction outside those terms should be sent to the publishers. The use of registered name, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant laws and regulations and therefore free for general use. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made. -
Girard Desargues, Maître De Pascal Eishi KUKITA
Girard Desargues, maître de Pascal Eishi KUKITA La vie et l’œuvre de Girard Desargues (1591-1661), savant et ingénieur du XVIIe siècle, sont aujourd’hui presque inconnues1. Pourtant les plus lucides de ses contemporains, dont Descartes et Pascal, tous deux grands géomètres qui ont marqué chacun à sa manière l’aube des sciences naturelles modernes, lui trouvaient une intelligence hors du commun. Une lecture attentive des correspondances de Descartes nous permettra de constater que le philosophe du cogito n’exagérait point en écrivant à Mersenne, au sujet de ses Méditations (1641) : Je serai bien aise que M. Desargues soit aussi un de mes juges, s’il lui plaît d’en prendre la peine, et je me fie plus en lui qu’en trois théologiens2. Quant à Pascal, publiant à l’âge de seize ans son premier article Essai pour les Coniques en 1640, il rendit un hommage vibrant à celui qu’il considérait comme son maître : Nous démontrerons aussi cette propriété, dont le premier inventeur est M. Desargues Lyonnais, un des grands esprits de ce temps et des 1 La littérature sur Desargues est franchement pauvre. Autant que nous le sachions, seuls quatre livres en français ont été publiés depuis XIXe siècle. N.-G. Poudra, Œuvres de Desargues, 2 vol., Léiber, 1864, rééd. fac-similé, Cambridge Univ. Press, 2011 (sigle : Pou). R. Taton, Œuvres mathématiques de G. Desargues, PUF, 1951, 2e éd., Vrin, 1988 (sigle : Tat). J. Dhombres et J. Sakarovitch (dir.), Desargues en son Temps, Blanchard, 1994 (sigle : DS). M. Chaboud, Girard Desargues, Bourgeois de Lyon, Mathématicien, Architecte, Lyon, Aléas, 1996 (sigle : Cha).