Pioneers in Optics: Christiaan Huygens
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The Swinging Spring: Regular and Chaotic Motion
References The Swinging Spring: Regular and Chaotic Motion Leah Ganis May 30th, 2013 Leah Ganis The Swinging Spring: Regular and Chaotic Motion References Outline of Talk I Introduction to Problem I The Basics: Hamiltonian, Equations of Motion, Fixed Points, Stability I Linear Modes I The Progressing Ellipse and Other Regular Motions I Chaotic Motion I References Leah Ganis The Swinging Spring: Regular and Chaotic Motion References Introduction The swinging spring, or elastic pendulum, is a simple mechanical system in which many different types of motion can occur. The system is comprised of a heavy mass, attached to an essentially massless spring which does not deform. The system moves under the force of gravity and in accordance with Hooke's Law. z y r φ x k m Leah Ganis The Swinging Spring: Regular and Chaotic Motion References The Basics We can write down the equations of motion by finding the Lagrangian of the system and using the Euler-Lagrange equations. The Lagrangian, L is given by L = T − V where T is the kinetic energy of the system and V is the potential energy. Leah Ganis The Swinging Spring: Regular and Chaotic Motion References The Basics In Cartesian coordinates, the kinetic energy is given by the following: 1 T = m(_x2 +y _ 2 +z _2) 2 and the potential is given by the sum of gravitational potential and the spring potential: 1 V = mgz + k(r − l )2 2 0 where m is the mass, g is the gravitational constant, k the spring constant, r the stretched length of the spring (px2 + y 2 + z2), and l0 the unstretched length of the spring. -
Classical Mechanics
Classical Mechanics Hyoungsoon Choi Spring, 2014 Contents 1 Introduction4 1.1 Kinematics and Kinetics . .5 1.2 Kinematics: Watching Wallace and Gromit ............6 1.3 Inertia and Inertial Frame . .8 2 Newton's Laws of Motion 10 2.1 The First Law: The Law of Inertia . 10 2.2 The Second Law: The Equation of Motion . 11 2.3 The Third Law: The Law of Action and Reaction . 12 3 Laws of Conservation 14 3.1 Conservation of Momentum . 14 3.2 Conservation of Angular Momentum . 15 3.3 Conservation of Energy . 17 3.3.1 Kinetic energy . 17 3.3.2 Potential energy . 18 3.3.3 Mechanical energy conservation . 19 4 Solving Equation of Motions 20 4.1 Force-Free Motion . 21 4.2 Constant Force Motion . 22 4.2.1 Constant force motion in one dimension . 22 4.2.2 Constant force motion in two dimensions . 23 4.3 Varying Force Motion . 25 4.3.1 Drag force . 25 4.3.2 Harmonic oscillator . 29 5 Lagrangian Mechanics 30 5.1 Configuration Space . 30 5.2 Lagrangian Equations of Motion . 32 5.3 Generalized Coordinates . 34 5.4 Lagrangian Mechanics . 36 5.5 D'Alembert's Principle . 37 5.6 Conjugate Variables . 39 1 CONTENTS 2 6 Hamiltonian Mechanics 40 6.1 Legendre Transformation: From Lagrangian to Hamiltonian . 40 6.2 Hamilton's Equations . 41 6.3 Configuration Space and Phase Space . 43 6.4 Hamiltonian and Energy . 45 7 Central Force Motion 47 7.1 Conservation Laws in Central Force Field . 47 7.2 The Path Equation . -
Floating and Platform Balances an Introduction
Floating and Platform Balances An introduction ©Darrah Artzner 3/2018 Floating and Platform Balances • Introduce main types • Discuss each in some detail including part identification and function • Testing and Inspecting • Cleaning tips • Lubrication • Performing repairs Balance Assembly Type Floating Platform Floating Balance Frame Spring stud Helicoid spring Hollow Tube Mounting Post Regulator Balance wheel Floating Balance cont. Jewel Roller Pin Paired weight Hollow Tube Safety Roller Pivot Wire Floating Balance cont. Example Retaining Hermle screws Safety Roller Note: moving fork Jewel cover Floating Balance cont. Inspecting and Testing (Balance assembly is removed from movement) • Inspect pivot (suspension) wire for distortion, corrosion, breakage. • Balance should appear to float between frame. Top and bottom distance. • Balance spring should be proportional and not distorted in any way. • Inspect jewels for cracks and or breakage. • Roller pin should be centered when viewed from front. (beat) • Rotate balance wheel three quarters of a turn (270°) and release. It should rotate smoothly with no distortion and should oscillate for several (3) minutes. Otherwise it needs attention. Floating Balance cont. Cleaning • Make sure the main spring has been let down before working on movement. • Use non-aqueous watch cleaner and/or rinse. • Agitate in cleaner/rinse by hand or briefly in ultrasonic. • Rinse twice and final in naphtha, Coleman fuel (or similar) or alcohol. • Allow to dry. (heat can be used with caution – ask me how I would do it.) Lubrication • There are two opinions. To lube or not to lube. • Place a vary small amount of watch oil on to the upper and lower jewel where the pivot wire passed through the jewel holes. -
Dynamics of the Elastic Pendulum Qisong Xiao; Shenghao Xia ; Corey Zammit; Nirantha Balagopal; Zijun Li Agenda
Dynamics of the Elastic Pendulum Qisong Xiao; Shenghao Xia ; Corey Zammit; Nirantha Balagopal; Zijun Li Agenda • Introduction to the elastic pendulum problem • Derivations of the equations of motion • Real-life examples of an elastic pendulum • Trivial cases & equilibrium states • MATLAB models The Elastic Problem (Simple Harmonic Motion) 푑2푥 푑2푥 푘 • 퐹 = 푚 = −푘푥 = − 푥 푛푒푡 푑푡2 푑푡2 푚 • Solve this differential equation to find 푥 푡 = 푐1 cos 휔푡 + 푐2 sin 휔푡 = 퐴푐표푠(휔푡 − 휑) • With velocity and acceleration 푣 푡 = −퐴휔 sin 휔푡 + 휑 푎 푡 = −퐴휔2cos(휔푡 + 휑) • Total energy of the system 퐸 = 퐾 푡 + 푈 푡 1 1 1 = 푚푣푡2 + 푘푥2 = 푘퐴2 2 2 2 The Pendulum Problem (with some assumptions) • With position vector of point mass 푥 = 푙 푠푖푛휃푖 − 푐표푠휃푗 , define 푟 such that 푥 = 푙푟 and 휃 = 푐표푠휃푖 + 푠푖푛휃푗 • Find the first and second derivatives of the position vector: 푑푥 푑휃 = 푙 휃 푑푡 푑푡 2 푑2푥 푑2휃 푑휃 = 푙 휃 − 푙 푟 푑푡2 푑푡2 푑푡 • From Newton’s Law, (neglecting frictional force) 푑2푥 푚 = 퐹 + 퐹 푑푡2 푔 푡 The Pendulum Problem (with some assumptions) Defining force of gravity as 퐹푔 = −푚푔푗 = 푚푔푐표푠휃푟 − 푚푔푠푖푛휃휃 and tension of the string as 퐹푡 = −푇푟 : 2 푑휃 −푚푙 = 푚푔푐표푠휃 − 푇 푑푡 푑2휃 푚푙 = −푚푔푠푖푛휃 푑푡2 Define 휔0 = 푔/푙 to find the solution: 푑2휃 푔 = − 푠푖푛휃 = −휔2푠푖푛휃 푑푡2 푙 0 Derivation of Equations of Motion • m = pendulum mass • mspring = spring mass • l = unstreatched spring length • k = spring constant • g = acceleration due to gravity • Ft = pre-tension of spring 푚푔−퐹 • r = static spring stretch, 푟 = 푡 s 푠 푘 • rd = dynamic spring stretch • r = total spring stretch 푟푠 + 푟푑 Derivation of Equations of Motion -
Newton.Indd | Sander Pinkse Boekproductie | 16-11-12 / 14:45 | Pag
omslag Newton.indd | Sander Pinkse Boekproductie | 16-11-12 / 14:45 | Pag. 1 e Dutch Republic proved ‘A new light on several to be extremely receptive to major gures involved in the groundbreaking ideas of Newton Isaac Newton (–). the reception of Newton’s Dutch scholars such as Willem work.’ and the Netherlands Jacob ’s Gravesande and Petrus Prof. Bert Theunissen, Newton the Netherlands and van Musschenbroek played a Utrecht University crucial role in the adaption and How Isaac Newton was Fashioned dissemination of Newton’s work, ‘is book provides an in the Dutch Republic not only in the Netherlands important contribution to but also in the rest of Europe. EDITED BY ERIC JORINK In the course of the eighteenth the study of the European AND AD MAAS century, Newton’s ideas (in Enlightenment with new dierent guises and interpre- insights in the circulation tations) became a veritable hype in Dutch society. In Newton of knowledge.’ and the Netherlands Newton’s Prof. Frans van Lunteren, sudden success is analyzed in Leiden University great depth and put into a new perspective. Ad Maas is curator at the Museum Boerhaave, Leiden, the Netherlands. Eric Jorink is researcher at the Huygens Institute for Netherlands History (Royal Dutch Academy of Arts and Sciences). / www.lup.nl LUP Newton and the Netherlands.indd | Sander Pinkse Boekproductie | 16-11-12 / 16:47 | Pag. 1 Newton and the Netherlands Newton and the Netherlands.indd | Sander Pinkse Boekproductie | 16-11-12 / 16:47 | Pag. 2 Newton and the Netherlands.indd | Sander Pinkse Boekproductie | 16-11-12 / 16:47 | Pag. -
Chapter 5 ANGULAR MOMENTUM and ROTATIONS
Chapter 5 ANGULAR MOMENTUM AND ROTATIONS In classical mechanics the total angular momentum L~ of an isolated system about any …xed point is conserved. The existence of a conserved vector L~ associated with such a system is itself a consequence of the fact that the associated Hamiltonian (or Lagrangian) is invariant under rotations, i.e., if the coordinates and momenta of the entire system are rotated “rigidly” about some point, the energy of the system is unchanged and, more importantly, is the same function of the dynamical variables as it was before the rotation. Such a circumstance would not apply, e.g., to a system lying in an externally imposed gravitational …eld pointing in some speci…c direction. Thus, the invariance of an isolated system under rotations ultimately arises from the fact that, in the absence of external …elds of this sort, space is isotropic; it behaves the same way in all directions. Not surprisingly, therefore, in quantum mechanics the individual Cartesian com- ponents Li of the total angular momentum operator L~ of an isolated system are also constants of the motion. The di¤erent components of L~ are not, however, compatible quantum observables. Indeed, as we will see the operators representing the components of angular momentum along di¤erent directions do not generally commute with one an- other. Thus, the vector operator L~ is not, strictly speaking, an observable, since it does not have a complete basis of eigenstates (which would have to be simultaneous eigenstates of all of its non-commuting components). This lack of commutivity often seems, at …rst encounter, as somewhat of a nuisance but, in fact, it intimately re‡ects the underlying structure of the three dimensional space in which we are immersed, and has its source in the fact that rotations in three dimensions about di¤erent axes do not commute with one another. -
On the Isochronism of Galilei's Horologium
IFToMM Workshop on History of MMS – Palermo 2013 On the isochronism of Galilei's horologium Francesco Sorge, Marco Cammalleri, Giuseppe Genchi DICGIM, Università di Palermo, [email protected], [email protected], [email protected] Abstract − Measuring the passage of time has always fascinated the humankind throughout the centuries. It is amazing how the general architecture of clocks has remained almost unchanged in practice to date from the Middle Ages. However, the foremost mechanical developments in clock-making date from the seventeenth century, when the discovery of the isochronism laws of pendular motion by Galilei and Huygens permitted a higher degree of accuracy in the time measure. Keywords: Time Measure, Pendulum, Isochronism Brief Survey on the Art of Clock-Making The first elements of temporal and spatial cognition among the primitive societies were associated with the course of natural events. In practice, the starry heaven played the role of the first huge clock of mankind. According to the philosopher Macrobius (4 th century), even the Latin term hora derives, through the Greek word ‘ώρα , from an Egyptian hieroglyph to be pronounced Heru or Horu , which was Latinized into Horus and was the name of the Egyptian deity of the sun and the sky, who was the son of Osiris and was often represented as a hawk, prince of the sky. Later on, the measure of time began to assume a rudimentary technical connotation and to benefit from the use of more or less ingenious devices. Various kinds of clocks developed to relatively high levels of accuracy through the Egyptian, Assyrian, Greek and Roman civilizations. -
A Guide to Space Law Terms: Spi, Gwu, & Swf
A GUIDE TO SPACE LAW TERMS: SPI, GWU, & SWF A Guide to Space Law Terms Space Policy Institute (SPI), George Washington University and Secure World Foundation (SWF) Editor: Professor Henry R. Hertzfeld, Esq. Research: Liana X. Yung, Esq. Daniel V. Osborne, Esq. December 2012 Page i I. INTRODUCTION This document is a step to developing an accurate and usable guide to space law words, terms, and phrases. The project developed from misunderstandings and difficulties that graduate students in our classes encountered listening to lectures and reading technical articles on topics related to space law. The difficulties are compounded when students are not native English speakers. Because there is no standard definition for many of the terms and because some terms are used in many different ways, we have created seven categories of definitions. They are: I. A simple definition written in easy to understand English II. Definitions found in treaties, statutes, and formal regulations III. Definitions from legal dictionaries IV. Definitions from standard English dictionaries V. Definitions found in government publications (mostly technical glossaries and dictionaries) VI. Definitions found in journal articles, books, and other unofficial sources VII. Definitions that may have different interpretations in languages other than English The source of each definition that is used is provided so that the reader can understand the context in which it is used. The Simple Definitions are meant to capture the essence of how the term is used in space law. Where possible we have used a definition from one of our sources for this purpose. When we found no concise definition, we have drafted the definition based on the more complex definitions from other sources. -
A Phenomenology of Galileo's Experiments with Pendulums
BJHS, Page 1 of 35. f British Society for the History of Science 2009 doi:10.1017/S0007087409990033 A phenomenology of Galileo’s experiments with pendulums PAOLO PALMIERI* Abstract. The paper reports new findings about Galileo’s experiments with pendulums and discusses their significance in the context of Galileo’s writings. The methodology is based on a phenomenological approach to Galileo’s experiments, supported by computer modelling and close analysis of extant textual evidence. This methodology has allowed the author to shed light on some puzzles that Galileo’s experiments have created for scholars. The pendulum was crucial throughout Galileo’s career. Its properties, with which he was fascinated from very early in his career, especially concern time. A 1602 letter is the earliest surviving document in which Galileo discusses the hypothesis of pendulum isochronism.1 In this letter Galileo claims that all pendulums are isochronous, and that he has long been trying to demonstrate isochronism mechanically, but that so far he has been unable to succeed. From 1602 onwards Galileo referred to pendulum isochronism as an admirable property but failed to demonstrate it. The pendulum is the most open-ended of Galileo’s artefacts. After working on my reconstructed pendulums for some time, I became convinced that the pendulum had the potential to allow Galileo to break new ground. But I also realized that its elusive nature sometimes threatened to undermine the progress Galileo was making on other fronts. It is this ambivalent nature that, I thought, might prove invaluable in trying to understand crucial aspects of Galileo’s innovative methodology. -
Computer-Aided Design and Kinematic Simulation of Huygens's
applied sciences Article Computer-Aided Design and Kinematic Simulation of Huygens’s Pendulum Clock Gloria Del Río-Cidoncha 1, José Ignacio Rojas-Sola 2,* and Francisco Javier González-Cabanes 3 1 Department of Engineering Graphics, University of Seville, 41092 Seville, Spain; [email protected] 2 Department of Engineering Graphics, Design, and Projects, University of Jaen, 23071 Jaen, Spain 3 University of Seville, 41092 Seville, Spain; [email protected] * Correspondence: [email protected]; Tel.: +34-953-212452 Received: 25 November 2019; Accepted: 9 January 2020; Published: 10 January 2020 Abstract: This article presents both the three-dimensional modelling of the isochronous pendulum clock and the simulation of its movement, as designed by the Dutch physicist, mathematician, and astronomer Christiaan Huygens, and published in 1673. This invention was chosen for this research not only due to the major technological advance that it represented as the first reliable meter of time, but also for its historical interest, since this timepiece embodied the theory of pendular movement enunciated by Huygens, which remains in force today. This 3D modelling is based on the information provided in the only plan of assembly found as an illustration in the book Horologium Oscillatorium, whereby each of its pieces has been sized and modelled, its final assembly has been carried out, and its operation has been correctly verified by means of CATIA V5 software. Likewise, the kinematic simulation of the pendulum has been carried out, following the approximation of the string by a simple chain of seven links as a composite pendulum. The results have demonstrated the exactitude of the clock. -
ALBERT VAN HELDEN + HUYGENS’S RING CASSINI’S DIVISION O & O SATURN’S CHILDREN
_ ALBERT VAN HELDEN + HUYGENS’S RING CASSINI’S DIVISION o & o SATURN’S CHILDREN )0g-_ DIBNER LIBRARY LECTURE , HUYGENS’S RING, CASSINI’S DIVISION & SATURN’S CHILDREN c !@ _+++++++++ l ++++++++++ _) _) _) _) _)HUYGENS’S RING, _)CASSINI’S DIVISION _) _)& _)SATURN’S CHILDREN _) _) _)DDDDD _) _) _)Albert van Helden _) _) _) , _) _) _)_ _) _) _) _) _) · _) _) _) ; {(((((((((QW(((((((((} , 20013–7012 Text Copyright ©2006 Albert van Helden. All rights reserved. A H is Professor Emeritus at Rice University and the Univer- HUYGENS’S RING, CASSINI’S DIVISION sity of Utrecht, Netherlands, where he resides and teaches on a regular basis. He received his B.S and M.S. from Stevens Institute of Technology, M.A. from the AND SATURN’S CHILDREN University of Michigan and Ph.D. from Imperial College, University of London. Van Helden is a renowned author who has published respected books and arti- cles about the history of science, including the translation of Galileo’s “Sidereus Nuncius” into English. He has numerous periodical contributions to his credit and has served on the editorial boards of Air and Space, 1990-present; Journal for the History of Astronomy, 1988-present; Isis, 1989–1994; and Tractrix, 1989–1995. During his tenure at Rice University (1970–2001), van Helden was instrumental in establishing the “Galileo Project,”a Web-based source of information on the life and work of Galileo Galilei and the science of his time. A native of the Netherlands, Professor van Helden returned to his homeland in 2001 to join the faculty of Utrecht University. -
A Royal 'Haagseklok'
THE SPLIT (Going and Strike) BARREL (top) p.16 Overview Pendulum Applications. The Going-wheel The Strike-wheel Ratchet-work Stop-work German Origins Hidden Stop Work English Variants WIND-ME MECHANISM? p.19 An "Up-Down" Indicator (Hypothetical Project) OOSTERWIJCK'S UNIQUE BOX CASE p.20 Overview Show Wood Carcass Construction Damage Control Mortised Hinges A Royal 'Haagse Klok' Reviewed by Keith Piggott FIRST ASSESSMENTS p.22 APPENDIX ONE - Technical, Dimensions, Tables with Comparable Coster Trains - (Dr Plomp's 'Chronology' D3 and D8) 25/7/1 0 Contents (Horological Foundation) APPENDIX TWO - Conservation of Unique Case General Conservation Issues - Oosterwijck‟s Kingwood and Ebony Box INTRODUCTION First Impressions. APPENDIX SIX - RH Provenance, Sir John Shaw Bt. Genealogy HUYGENS AUTHORITIES p.1 Collections and Exhibitions Didactic Scholarship PART II. „OSCILLATORIUM‟ p.24 Who was Severijn Oosterwijck? Perspectives, Hypotheses, Open Research GENERAL OBSERVATIONS p.2 The Inspection Author's Foreword - Catalyst and Conundrums Originality 1. Coster‟s Other Contracts? p.24 Unique Features 2. Coster‟s Clockmakers? p.24 Plomp‟s Characteristic Properties 3. Fromanteel Connections? p.25 Comparables 4. „Secreet‟ Constructions? p.25 Unknown Originator : German Antecedents : Application to Galilei's Pendulum : Foreknowledge of Burgi : The Secret Outed? : Derivatives : Whose Secret? PART I. „HOROLOGIUM‟ p.3 5. Personal Associations? p.29 6. The Seconds‟ Hiatus? p.29 The Clock Treffler's Copy : Later Seconds‟ Clocks : Oosterwijck‟s Options. 7. Claims to Priority? p.33 THE VELVET DIALPLATE p.3 8. Valuation? p.34 Overview Signature Plate APPENDIX THREE - Open Research Projects, Significant Makers Chapter Ring User-Access Data Comparable Pendulum Trains, Dimensions.