Orbital Mechanics
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How Dualists Should (Not) Respond to the Objection from Energy
c 2019 Imprint Academic Mind & Matter Vol. 17(1), pp. 95–121 How Dualists Should (Not) Respond to the Objection from Energy Conservation Alin C. Cucu International Academy of Philosophy Mauren, Liechtenstein and J. Brian Pitts Faculty of Philosophy and Trinity College University of Cambridge, United Kingdom Abstract The principle of energy conservation is widely taken to be a se- rious difficulty for interactionist dualism (whether property or sub- stance). Interactionists often have therefore tried to make it satisfy energy conservation. This paper examines several such attempts, especially including E. J. Lowe’s varying constants proposal, show- ing how they all miss their goal due to lack of engagement with the physico-mathematical roots of energy conservation physics: the first Noether theorem (that symmetries imply conservation laws), its converse (that conservation laws imply symmetries), and the locality of continuum/field physics. Thus the “conditionality re- sponse”, which sees conservation as (bi)conditional upon symme- tries and simply accepts energy non-conservation as an aspect of interactionist dualism, is seen to be, perhaps surprisingly, the one most in accord with contemporary physics (apart from quantum mechanics) by not conflicting with mathematical theorems basic to physics. A decent objection to interactionism should be a posteri- ori, based on empirically studying the brain. 1. The Objection from Energy Conservation Formulated Among philosophers of mind and metaphysicians, it is widely believed that the principle of energy conservation poses a serious problem to inter- actionist dualism. Insofar as this objection afflicts interactionist dualisms, it applies to property dualism of that sort (i.e., not epiphenomenalist) as much as to substance dualism (Crane 2001, pp. -
Realizing Monads
anDrás kornai Realizing Monads ABSTrACT We reconstruct monads as cyclic finite state automata whose states are what Leibniz calls perceptions and whose transitions are automatically triggered by the next time tick he calls entelechy. This goes some way toward explaining key as- pects of the Monadology, in particular, the lack of inputs and outputs (§7) and the need for universal harmony (§59). 1. INTrODUCTION Monads are important both in category theory and in programming language de- sign, clearly demonstrating that Leibniz is greatly appreciated as the conceptual forerunner of much of abstract thought both in mathematics and in computer sci- ence. Yet we suspect that Leibniz, the engineer, designer of the Stepped reck- oner, would use the resources of the modern world to build a very different kind of monad. Throughout this paper, we confront Leibniz with our contemporary scientific understanding of the world. This is done to make sure that what we say is not “concretely empty” in the sense of Unger (2014). We are not interested in what we can say about Leibniz, but rather in what Leibniz can say about our cur- rent world model. readers expecting some glib demonstration of how our current scientific theories make Leibniz look like a fool will be sorely disappointed. Looking around, and finding a well-built Calculus ratiocinator in Turing ma- chines, pointer machines, and similar abstract models of computation, Leibniz would no doubt consider his Characteristica Universalis well realized in modern proof checkers such as Mizar, Coq, or Agda to the extent mathematical deduc- tion is concerned, but would be somewhat disappointed in their applicability to natural philosophy in general. -
Astrodynamics
Politecnico di Torino SEEDS SpacE Exploration and Development Systems Astrodynamics II Edition 2006 - 07 - Ver. 2.0.1 Author: Guido Colasurdo Dipartimento di Energetica Teacher: Giulio Avanzini Dipartimento di Ingegneria Aeronautica e Spaziale e-mail: [email protected] Contents 1 Two–Body Orbital Mechanics 1 1.1 BirthofAstrodynamics: Kepler’sLaws. ......... 1 1.2 Newton’sLawsofMotion ............................ ... 2 1.3 Newton’s Law of Universal Gravitation . ......... 3 1.4 The n–BodyProblem ................................. 4 1.5 Equation of Motion in the Two-Body Problem . ....... 5 1.6 PotentialEnergy ................................. ... 6 1.7 ConstantsoftheMotion . .. .. .. .. .. .. .. .. .... 7 1.8 TrajectoryEquation .............................. .... 8 1.9 ConicSections ................................... 8 1.10 Relating Energy and Semi-major Axis . ........ 9 2 Two-Dimensional Analysis of Motion 11 2.1 ReferenceFrames................................. 11 2.2 Velocity and acceleration components . ......... 12 2.3 First-Order Scalar Equations of Motion . ......... 12 2.4 PerifocalReferenceFrame . ...... 13 2.5 FlightPathAngle ................................. 14 2.6 EllipticalOrbits................................ ..... 15 2.6.1 Geometry of an Elliptical Orbit . ..... 15 2.6.2 Period of an Elliptical Orbit . ..... 16 2.7 Time–of–Flight on the Elliptical Orbit . .......... 16 2.8 Extensiontohyperbolaandparabola. ........ 18 2.9 Circular and Escape Velocity, Hyperbolic Excess Speed . .............. 18 2.10 CosmicVelocities -
Uncommon Sense in Orbit Mechanics
AAS 93-290 Uncommon Sense in Orbit Mechanics by Chauncey Uphoff Consultant - Ball Space Systems Division Boulder, Colorado Abstract: This paper is a presentation of several interesting, and sometimes valuable non- sequiturs derived from many aspects of orbital dynamics. The unifying feature of these vignettes is that they all demonstrate phenomena that are the opposite of what our "common sense" tells us. Each phenomenon is related to some application or problem solution close to or directly within the author's experience. In some of these applications, the common part of our sense comes from the fact that we grew up on t h e surface of a planet, deep in its gravity well. In other examples, our mathematical intuition is wrong because our mathematical model is incomplete or because we are accustomed to certain kinds of solutions like the ones we were taught in school. The theme of the paper is that many apparently unsolvable problems might be resolved by the process of guessing the answer and trying to work backwards to the problem. The ability to guess the right answer in the first place is a part of modern magic. A new method of ballistic transfer from Earth to inner solar system targets is presented as an example of the combination of two concepts that seem to work in reverse. Introduction Perhaps the simplest example of uncommon sense in orbit mechanics is the increase of speed of a satellite as it "decays" under the influence of drag caused by collisions with the molecules of the upper atmosphere. In everyday life, when we slow something down, we expect it to slow down, not to speed up. -
AFSPC-CO TERMINOLOGY Revised: 12 Jan 2019
AFSPC-CO TERMINOLOGY Revised: 12 Jan 2019 Term Description AEHF Advanced Extremely High Frequency AFB / AFS Air Force Base / Air Force Station AOC Air Operations Center AOI Area of Interest The point in the orbit of a heavenly body, specifically the moon, or of a man-made satellite Apogee at which it is farthest from the earth. Even CAP rockets experience apogee. Either of two points in an eccentric orbit, one (higher apsis) farthest from the center of Apsis attraction, the other (lower apsis) nearest to the center of attraction Argument of Perigee the angle in a satellites' orbit plane that is measured from the Ascending Node to the (ω) perigee along the satellite direction of travel CGO Company Grade Officer CLV Calculated Load Value, Crew Launch Vehicle COP Common Operating Picture DCO Defensive Cyber Operations DHS Department of Homeland Security DoD Department of Defense DOP Dilution of Precision Defense Satellite Communications Systems - wideband communications spacecraft for DSCS the USAF DSP Defense Satellite Program or Defense Support Program - "Eyes in the Sky" EHF Extremely High Frequency (30-300 GHz; 1mm-1cm) ELF Extremely Low Frequency (3-30 Hz; 100,000km-10,000km) EMS Electromagnetic Spectrum Equitorial Plane the plane passing through the equator EWR Early Warning Radar and Electromagnetic Wave Resistivity GBR Ground-Based Radar and Global Broadband Roaming GBS Global Broadcast Service GEO Geosynchronous Earth Orbit or Geostationary Orbit ( ~22,300 miles above Earth) GEODSS Ground-Based Electro-Optical Deep Space Surveillance -
The Speed of a Geosynchronous Satellite Is ___
Physics 106 Lecture 9 Newton’s Law of Gravitation SJ 7th Ed.: Chap 13.1 to 2, 13.4 to 5 • Historical overview • N’Newton’s inverse-square law of graviiitation Force Gravitational acceleration “g” • Superposition • Gravitation near the Earth’s surface • Gravitation inside the Earth (concentric shells) • Gravitational potential energy Related to the force by integration A conservative force means it is path independent Escape velocity Example A geosynchronous satellite circles the earth once every 24 hours. If the mass of the earth is 5.98x10^24 kg; and the radius of the earth is 6.37x10^6 m., how far above the surface of the earth does a geosynchronous satellite orbit the earth? G=6.67x10-11 Nm2/kg2 The speed of a geosynchronous satellite is ______. 1 Goal Gravitational potential energy for universal gravitational force Gravitational Potential Energy WUgravity= −Δ gravity Near surface of Earth: Gravitational force of magnitude of mg, pointing down (constant force) Æ U = mgh Generally, gravit. potential energy for a system of m1 & m2 G Gmm12 mm F = Attractive force Ur()=− G12 12 r 2 g 12 12 r12 Zero potential energy is chosen for infinite distance between m1 and m2. Urg ()012 = ∞= Æ Gravitational potential energy is always negative. 2 mm12 Urg ()12 =− G r12 r r Ug=0 1 U(r1) Gmm U =− 12 g r Mechanical energy 11 mM EKUrmvMVG=+ ( ) =22 + − mech 22 r m V r v M E_mech is conserved, if gravity is the only force that is doing work. 1 2 MV is almost unchanged. If M >>> m, 2 1 2 mM ÆWe can define EKUrmvG=+ ( ) = − mech 2 r 3 Example: A stone is thrown vertically up at certain speed from the surface of the Moon by Superman. -
16.346 Astrodynamics Fall 2008
MIT OpenCourseWare http://ocw.mit.edu 16.346 Astrodynamics Fall 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. Lecture 2 The Two Body Problem Continued The Eccentricity Vector or The Laplace Vector µ µe = v × h − r r Explicit Form of the Velocity Vector #3.1 Using the expansion of the triple vector product a × (b × c)=(a · c)b − (a · b)c we have µ h × µe = h × (v × h) − h × r = h2v − (h · v)h − µh × i = h2v − µh i × i r r h r since h and v are perpendicular. Therefore: µ h × µe =⇒ v = i × (e + i ) h h r or hv = i × (e i + i )=e i × i + i × i = e i + i µ h e r h e h r p θ Then since ip = sin f ir + cos f iθ we have hv = e sin f i +(1+e cos f) i µ r θ which is the basic relation for representing the velocity vector in the Hodograph Plane. See Page 1 of Lecture 4 Conservation of Energy hv hv p p 2 1 · = v · v = 2(1 + e cos f)+e 2 − 1=2× − (1 − e 2)=p − µ µ µ r r a which can be written in either of two separate forms each having its own name: 1 µ µ 1 Energy Integral v2 − = − = c 2 r 2a 2 3 2 1 Vis-Viva Integral v 2 = µ − r a The constant c3 is used by Forest Ray Moulton, a Professor at the University of Chicago in his 1902 book “An Introduction to Celestial Mechanics” — the first book on the subject written by an American. -
Leibniz' Dynamical Metaphysicsand the Origins
LEIBNIZ’ DYNAMICAL METAPHYSICSAND THE ORIGINS OF THE VIS VIVA CONTROVERSY* by George Gale Jr. * I am grateful to Marjorie Grene, Neal Gilbert, Ronald Arbini and Rom Harr6 for their comments on earlier drafts of this essay. Systematics Vol. 11 No. 3 Although recent work has begun to clarify the later history and development of the vis viva controversy, the origins of the conflict arc still obscure.1 This is understandable, since it was Leibniz who fired the initial barrage of the battle; and, as always, it is extremely difficult to disentangle the various elements of the great physicist-philosopher’s thought. His conception includes facets of physics, mathematics and, of course, metaphysics. However, one feature is essential to any possible understanding of the genesis of the debate over vis viva: we must note, as did Leibniz, that the vis viva notion was to emerge as the first element of a new science, which differed significantly from that of Descartes and Newton, and which Leibniz called the science of dynamics. In what follows, I attempt to clarify the various strands which were woven into the vis viva concept, noting especially the conceptual framework which emerged and later evolved into the science of dynamics as we know it today. I shall argue, in general, that Leibniz’ science of dynamics developed as a consistent physical interpretation of certain of his metaphysical and mathematical beliefs. Thus the following analysis indicates that at least once in the history of science, an important development in physical conceptualization was intimately dependent upon developments in metaphysical conceptualization. 1. -
Lesson 3: Moons, Rings Relationships
GETTING TO KNOW SATURN LESSON Moons, Rings, and Relationships 3 3–4 hrs Students design their own experiments to explore the fundamental force of gravity, and then extend their thinking to how gravity acts to keep objects like moons and ring particles in orbit. Students use the contexts of the Solar System and the Saturn system MEETS NATIONAL to explore the nature of orbits. The lesson SCIENCE EDUCATION enables students to correct common mis- STANDARDS: conceptions about gravity and orbits and to Science as Inquiry • Abilities learn how orbital speed decreases as the dis- Prometheus and Pandora, two of Saturn’s moons, “shepherd” necessary to Saturn’s F ring. scientific inquiry tance from the object being orbited increases. Physical Science • Motions and PREREQUISITE SKILLS BACKGROUND INFORMATION forces Working in groups Background for Lesson Discussion, page 66 Earth and Space Science Reading a chart of data Questions, page 71 • Earth in the Plotting points on a graph Answers in Appendix 1, page 225 Solar System 1–21: Saturn 22–34: Rings 35–50: Moons EQUIPMENT, MATERIALS, AND TOOLS For the teacher Materials to reproduce Photocopier (for transparencies & copies) Figures 1–10 are provided at the end of Overhead projector this lesson. Chalkboard, whiteboard, or large easel FIGURE TRANSPARENCY COPIES with paper; chalk or markers 11 21 For each group of 3 to 4 students 31 Large plastic or rubber ball 4 1 per student Paper, markers, pencils 5 1 1 per student 6 1 for teacher 7 1 (optional) 1 for teacher 8 1 per student 9 1 (optional) 1 per student 10 1 (optional) 1 for teacher 65 Saturn Educator Guide • Cassini Program website — http://www.jpl.nasa.gov/cassini/educatorguide • EG-1999-12-008-JPL Background for Lesson Discussion LESSON 3 Science as inquiry The nature of Saturn’s rings and how (See Procedures & Activities, Part I, Steps 1-6) they move (See Procedures & Activities, Part IIa, Step 3) Part I of the lesson offers students a good oppor- tunity to experience science as inquiry. -
Leibniz's Optics and Contingency in Nature
Leibniz's Optics and Contingency in Nature The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation McDonough, Jeffrey K. 2010. Leibniz's Optics and Contingency in Nature. Perspectives on Science 18(4): 432-455. Published Version doi:10.1162/POSC_a_00017 Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:5128571 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#OAP Leibniz’s Optics and Contingency in Nature Jeffrey K. McDonough Department of Philosophy Harvard University 1 Abstract In the late 1670’s to early 1680’s, Leibniz came to hold that the laws of nature are paradigmatically contingent, that they provide the basis for a new argument from design, and that they presuppose the existence of active, goal-directed powers reminiscent of Aristotelian entelechies. In this essay, I argue that the standard view according to which Leibniz forges these signature theses in the domain of physics and opportunistically carries them over to the domain of optics gets things essentially the wrong way around. The crucial nexus of views at the heart of Leibniz’s mature philosophical understanding of the laws of nature has its most intelligible roots in his optical derivations, which appear to have paved the way – both historically and conceptually – for the philosophical significance he assigns to his discoveries in the domain of physics. -
Calculation of Moon Phases and 24 Solar Terms
Calculation of Moon Phases and 24 Solar Terms Yuk Tung Liu (廖²棟) First draft: 2018-10-24, Last major revision: 2021-06-12 Chinese Versions: ³³³qqq---文文文 简简简SSS---文文文 This document explains the method used to compute the times of the moon phases and 24 solar terms. These times are important in the calculation of the Chinese calendar. See this page for an introduction to the 24 solar terms, and this page for an introduction to the Chinese calendar calculation. Computation of accurate times of moon phases and 24 solar terms is complicated, but today all the necessary resources are freely available. Anyone familiar with numerical computation and computer programming can follow the procedure outlined in this document to do the computation. Before stating the procedure, it is useful to have a basic understanding of the basic concepts behind the computation. I assume that readers are already familiar with the important astronomy concepts mentioned on this page. In Section 1, I briefly introduce the barycentric dynamical time (TDB) used in modern ephemerides, and its connection to terrestrial time (TT) and international atomic time (TAI). Readers who are not familiar with general relativity do not have to pay much attention to the formulas there. Section 2 introduces the various coordinate systems used in modern astronomy. Section 3 lists the formulas for computing the IAU 2006/2000A precession and nutation matrices. One important component in the computation of accurate times of moon phases and 24 solar terms is an accurate ephemeris of the Sun and Moon. I use the ephemerides developed by the Jet Propulsion Laboratory (JPL) for the computation. -
Up, Up, and Away by James J
www.astrosociety.org/uitc No. 34 - Spring 1996 © 1996, Astronomical Society of the Pacific, 390 Ashton Avenue, San Francisco, CA 94112. Up, Up, and Away by James J. Secosky, Bloomfield Central School and George Musser, Astronomical Society of the Pacific Want to take a tour of space? Then just flip around the channels on cable TV. Weather Channel forecasts, CNN newscasts, ESPN sportscasts: They all depend on satellites in Earth orbit. Or call your friends on Mauritius, Madagascar, or Maui: A satellite will relay your voice. Worried about the ozone hole over Antarctica or mass graves in Bosnia? Orbital outposts are keeping watch. The challenge these days is finding something that doesn't involve satellites in one way or other. And satellites are just one perk of the Space Age. Farther afield, robotic space probes have examined all the planets except Pluto, leading to a revolution in the Earth sciences -- from studies of plate tectonics to models of global warming -- now that scientists can compare our world to its planetary siblings. Over 300 people from 26 countries have gone into space, including the 24 astronauts who went on or near the Moon. Who knows how many will go in the next hundred years? In short, space travel has become a part of our lives. But what goes on behind the scenes? It turns out that satellites and spaceships depend on some of the most basic concepts of physics. So space travel isn't just fun to think about; it is a firm grounding in many of the principles that govern our world and our universe.