Understanding Tides the Ocean
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Of Universal Gravitation and of the Theory of Relativity
ASTRONOMICAL APPLICATIONS OF THE LAW OF UNIVERSAL GRAVITATION AND OF THE THEORY OF RELATIVITY By HUGH OSCAR PEEBLES Bachelor of Science The University of Texas Austin, Texas 1955 Submitted to the faculty of the Graduate School of the Oklahoma State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August, 1960 ASTRONOMICAL APPLICATIONS OF THE LAW OF UNIVERSAL GRAVITATION AND OF THE THEORY OF RELATIVITY Report Approved: Dean of the Graduate School ii ACKNOWLEDGEMENT I express my deep appreciation to Dr. Leon w. Schroeder, Associate Professor of Physics, for his counsel, his criticisms, and his interest in the preparation of this study. My appre ciation is also extended to Dr. James H. Zant, Professor of Mathematics, for his guidance in the development of my graduate program. iii TABLE OF CONTENTS Chapter Page I. INTRODUCTION. 1 II. THE EARTH-MOON T"EST OF THE LAW OF GRAVITATION 4 III. DERIVATION OF KEPLER'S LAWS OF PLAN.ET.ARY MOTION FROM THE LAW OF UNIVERSAL GRAVITATION. • • • • • • • • • 9 The First Law-Law of Elliptical Paths • • • • • 10 The Second Law-Law of Equal Areas • • • • • • • 15 The Third Law-Harmonic Law • • • • • • • 19 IV. DETERMINATION OF THE MASSES OF ASTRONOMICAL BODIES. 20 V. ELEMENTARY THEORY OF TIDES. • • • • • • • • • • • • 26 VI. ELEMENTARY THEORY OF THE EQUATORIAL BULGE OF PLANETS 33 VII. THE DISCOVERY OF NEW PLANETS. • • • • • • • • • 36 VIII. ASTRONOMICAL TESTS OF THE THEORY OF RELATIVITY. 40 BIBLIOGRAPHY . 45 iv LIST OF FIGURES Figure Page 1. Fall of the Uoon Toward the Earth • • • • • • • • • • 6 2. Newton's Calculation of the Earth's Gravitational Ef- fect on the Moon. -
Chapter 5 Water Levels and Flow
253 CHAPTER 5 WATER LEVELS AND FLOW 1. INTRODUCTION The purpose of this chapter is to provide the hydrographer and technical reader the fundamental information required to understand and apply water levels, derived water level products and datums, and water currents to carry out field operations in support of hydrographic surveying and mapping activities. The hydrographer is concerned not only with the elevation of the sea surface, which is affected significantly by tides, but also with the elevation of lake and river surfaces, where tidal phenomena may have little effect. The term ‘tide’ is traditionally accepted and widely used by hydrographers in connection with the instrumentation used to measure the elevation of the water surface, though the term ‘water level’ would be more technically correct. The term ‘current’ similarly is accepted in many areas in connection with tidal currents; however water currents are greatly affected by much more than the tide producing forces. The term ‘flow’ is often used instead of currents. Tidal forces play such a significant role in completing most hydrographic surveys that tide producing forces and fundamental tidal variations are only described in general with appropriate technical references in this chapter. It is important for the hydrographer to understand why tide, water level and water current characteristics vary both over time and spatially so that they are taken fully into account for survey planning and operations which will lead to successful production of accurate surveys and charts. Because procedures and approaches to measuring and applying water levels, tides and currents vary depending upon the country, this chapter covers general principles using documented examples as appropriate for illustration. -
II. Causes of Tides III. Tidal Variations IV. Lunar Day and Frequency of Tides V
Tides I. What are Tides? II. Causes of Tides III. Tidal Variations IV. Lunar Day and Frequency of Tides V. Monitoring Tides Wikimedia FoxyOrange [CC BY-SA 3.0 Tides are not explicitly included in the NGSS PerFormance Expectations. From the NGSS Framework (M.S. Space Science): “There is a strong emphasis on a systems approach, using models oF the solar system to explain astronomical and other observations oF the cyclic patterns oF eclipses, tides, and seasons.” From the NGSS Crosscutting Concepts: Observed patterns in nature guide organization and classiFication and prompt questions about relationships and causes underlying them. For Elementary School: • Similarities and diFFerences in patterns can be used to sort, classiFy, communicate and analyze simple rates oF change For natural phenomena and designed products. • Patterns oF change can be used to make predictions • Patterns can be used as evidence to support an explanation. For Middle School: • Graphs, charts, and images can be used to identiFy patterns in data. • Patterns can be used to identiFy cause-and-eFFect relationships. The topic oF tides have an important connection to global change since spring tides and king tides are causing coastal Flooding as sea level has been rising. I. What are Tides? Tides are one oF the most reliable phenomena on Earth - they occur on a regular and predictable cycle. Along with death and taxes, tides are a certainty oF liFe. Tides are apparent changes in local sea level that are the result of long-period waves that move through the oceans. Photos oF low and high tide on the coast oF the Bay oF Fundy in Canada. -
Building Structures on the Moon and Mars: Engineering Challenges and Structural Design Parameters for Proposed Habitats
Building Structures on the Moon and Mars: Engineering Challenges and Structural Design Parameters for Proposed Habitats Ramesh B. Malla, Ph.D., F. ASCE, A.F. AIAA Professor Department of Civil and Environmental Engineering University of Connecticut, Storrs, CT 06269 (E-Mail: [email protected]) Presented at the Breakout Panel Session- Theme C - Habitats (Preparation and Architecture) RETH Workshop- Grand Challenges and Key Research Questions to Achieve Resilient Long-Term Extraterrestrial Habitats Purdue University; October 22-23, 2018 What is Structural Resiliency? Characterized by four traits: Robustness Ability to maintain critical functions in crisis Minimization of direct and indirect Resourcefulness losses from hazards through enhanced Ability to effectively manage crisis as it resistance and robustness to extreme unfolds events, as well as more effective Rapid Recovery recovery strategies. Reconstitute normal operations quickly and effectively Redundancy Backup resources to support originals Per: National Infrastructure Advisory Council, 2009 Hazard Sources & Potential Lunar Habitats Potential Hazard Sources Available Habitat Types Impact (Micrometeorite, Debris) Inflatable Hard Vacuum Membrane Extreme Temperature Rigid-Frame Structure Seismic Activity Hybrid Frame- Low Gravity “Bessel Crater” - https://www.lpi.usra.edu/science/kiefer/Education/SSRG2- Craters/craterstructure.html Membrane Radiation Structure Galactic Cosmic Rays (GCR) Subsurface Solar-Emitted Particles (SEP) Variants Malla, et al. (1995) -
The Calendars of India
The Calendars of India By Vinod K. Mishra, Ph.D. 1 Preface. 4 1. Introduction 5 2. Basic Astronomy behind the Calendars 8 2.1 Different Kinds of Days 8 2.2 Different Kinds of Months 9 2.2.1 Synodic Month 9 2.2.2 Sidereal Month 11 2.2.3 Anomalistic Month 12 2.2.4 Draconic Month 13 2.2.5 Tropical Month 15 2.2.6 Other Lunar Periodicities 15 2.3 Different Kinds of Years 16 2.3.1 Lunar Year 17 2.3.2 Tropical Year 18 2.3.3 Siderial Year 19 2.3.4 Anomalistic Year 19 2.4 Precession of Equinoxes 19 2.5 Nutation 21 2.6 Planetary Motions 22 3. Types of Calendars 22 3.1 Lunar Calendar: Structure 23 3.2 Lunar Calendar: Example 24 3.3 Solar Calendar: Structure 26 3.4 Solar Calendar: Examples 27 3.4.1 Julian Calendar 27 3.4.2 Gregorian Calendar 28 3.4.3 Pre-Islamic Egyptian Calendar 30 3.4.4 Iranian Calendar 31 3.5 Lunisolar calendars: Structure 32 3.5.1 Method of Cycles 32 3.5.2 Improvements over Metonic Cycle 34 3.5.3 A Mathematical Model for Intercalation 34 3.5.3 Intercalation in India 35 3.6 Lunisolar Calendars: Examples 36 3.6.1 Chinese Lunisolar Year 36 3.6.2 Pre-Christian Greek Lunisolar Year 37 3.6.3 Jewish Lunisolar Year 38 3.7 Non-Astronomical Calendars 38 4. Indian Calendars 42 4.1 Traditional (Siderial Solar) 42 4.2 National Reformed (Tropical Solar) 49 4.3 The Nānakshāhī Calendar (Tropical Solar) 51 4.5 Traditional Lunisolar Year 52 4.5 Traditional Lunisolar Year (vaisnava) 58 5. -
Equilibrium Model of Tides Highly Idealized, but Very Instructive, View of Tides
Tides Outline • Equilibrium Theory of Tides — diurnal, semidiurnal and mixed semidiurnal tides — spring and neap tides • Dynamic Theory of Tides — rotary tidal motion — larger tidal ranges in coastal versus open-ocean regions • Special Cases — Forcing ocean water into a narrow embayment — Tidal forcing that is in resonance with the tide wave Equilibrium Model of Tides Highly Idealized, but very instructive, View of Tides • Tide wave treated as a deep-water wave in equilibrium with lunar/solar forcing • No interference of tide wave propagation by continents Tidal Patterns for Various Locations 1 Looking Down on Top of the Earth The Earth’s Rotation Under the Tidal Bulge Produces the Rise moon and Fall of Tides over an Approximately 24h hour period Note: This is describing the ‘hypothetical’ condition of a 100% water planet Tidal Day = 24h + 50min It takes 50 minutes for the earth to rotate 12 degrees of longitude Earth & Moon Orbit Around Sun 2 R b a P Fa = Gravity Force on a small mass m at point a from the gravitational attraction between the small mass and the moon of mass M Fa = Centrifugal Force on a due to rotation about the center of mass of the two mass system using similar arguments The Main Point: Force at and point a and b are equal and opposite. It can be shown that the upward (normal the the earth’s surface) tidal force on a parcel of water produced by the moon’s gravitational attraction is small (1 part in 9 million) compared to the downward gravitation force on that parcel of water caused by earth’s on gravitational attraction. -
Multi-Lunar Day Polar Missions with a Solar-Only Rover. A. Colaprete1, R
Survive the Lunar Night Workshop 2018 (LPI Contrib. No. 2106) 7007.pdf Multi-Lunar Day Polar Missions with a Solar-Only Rover. A. Colaprete1, R. C. Elphic1, M. Shirley1, M. Siegler2, 1NASA Ames Research Center, Moffett Field, CA, 2Planetary Science Institute, Tucson, AZ Introduction: Resource Prospector (RP) was a lu- Polar Solar “Oases”: Numerous studies have nar HEOMD/Advanced Exploration Systems volatiles identified regions near the lunar poles that have sus- prospecting mission developed for potential flight in tained periods of solar illumination. In some places the early 2020s. The mission includes a rover-borne these periods of sustained sunlight extend across sever- payload that (1) can locate surface and near-subsurface al lunations, while others have very short (24-48 hours) volatiles, (2) excavate and analyze samples of the vola- nights. A study was conducted to evaluate if the RP tile-bearing regolith, and (3) demonstrate the form, rover system could take advantage of these “oases” to extractability and usefulness of the materials. The pri- survive the lunar night. While the Earth would set, as mary mission goal for RP is to evaluate the In-Situ seen by the rover, every approximately 2-weeks, these Resource Utilization (ISRU) potential of the lunar “oases” could provide sufficient power, and have lu- poles, to determine their utility within future NASA nar-nights short enough, for the rover system to sur- and commercial spaceflight architectures. While the vive. current RP rover design did not require a system that Results: The study focused in the area surrounding could survive lunar nights, it has been demonstrated the north pole crater Hermite-A (primarily due to the that the current design could conduct multi-lunar day fidelity of existing traverse planner data sets in this missions by taking advantage of areas that receive pro- area). -
Lunar Sourcebook : a User's Guide to the Moon
3 THE LUNAR ENVIRONMENT David Vaniman, Robert Reedy, Grant Heiken, Gary Olhoeft, and Wendell Mendell 3.1. EARTH AND MOON COMPARED fluctuations, low gravity, and the virtual absence of any atmosphere. Other environmental factors are not The differences between the Earth and Moon so evident. Of these the most important is ionizing appear clearly in comparisons of their physical radiation, and much of this chapter is devoted to the characteristics (Table 3.1). The Moon is indeed an details of solar and cosmic radiation that constantly alien environment. While these differences may bombard the Moon. Of lesser importance, but appear to be of only academic interest, as a measure necessary to evaluate, are the hazards from of the Moon’s “abnormality,” it is important to keep in micrometeoroid bombardment, the nuisance of mind that some of the differences also provide unique electrostatically charged lunar dust, and alien lighting opportunities for using the lunar environment and its conditions without familiar visual clues. To introduce resources in future space exploration. these problems, it is appropriate to begin with a Despite these differences, there are strong bonds human viewpoint—the Apollo astronauts’ impressions between the Earth and Moon. Tidal resonance of environmental factors that govern the sensations of between Earth and Moon locks the Moon’s rotation working on the Moon. with one face (the “nearside”) always toward Earth, the other (the “farside”) always hidden from Earth. 3.2. THE ASTRONAUT EXPERIENCE The lunar farside is therefore totally shielded from the Earth’s electromagnetic noise and is—electro- Working within a self-contained spacesuit is a magnetically at least—probably the quietest location requirement for both survival and personal mobility in our part of the solar system. -
Waves and Tides the Preceding Sections Have Dealt with the Types Of
CHAPTER XIV Waves and Tides .......................................................................................................... Introduction The preceding sections have dealt with the types of motion in the ocean that bring about transport of water massesin a definite direction during a considerable length of time. They have also dealt with the random motion, the turbulence, which is superimposed upon the general flow. Besidesthese types, one has also to consider the oscillating motion characteristic of waves. In general, this motion manifests itself to the observer more by the riseand fall of the sea surface than by the motion of the individual water particles. Waves have attracted attention since before the beginning of recorded history, and in recent years they have been the subject of extensive theoretical studies. Surveys of our knowledge as to the character of ocean waves have been presented by Cornish (1912, 1934), Krtimmel (1911), Patton and Mariner (1932) and by Defant (1929). Lamb (1932) has discussed the hydrodynamic theories of waves, and Thorade (1931) has given a comprehensive review of the theoretical studies of ocean waves and has compiled a long list of literature covering the period from 1687 to 1930. Our understanding of the waves of the ocean, how they are formed and how they travel, is as yet by no means complete. The reason is, in the first place, that actual observations at sea are so difficult that the characteristicsof the waves cannot easily be determined. In the second place, the theories that serve to bring the observed sequence of events in nature into intimate connection with experience gained by other methods of study are still incomplete, particularly because most theories are based on classicalhydrodynamics, which deal with wave motion in an idealized fluid. -
Workshop Report
WORKSHOP REPORT July 2019 This report was compiled by Andrew Petro, Anna Schonwald, Chris Britt, Renee Weber, Jeff Sheehy, Allison Zuniga, and Lee Mason. Contents Page EXECUTIVE SUMMARY AND RECOMMENDATIONS 2 WORKSHOP SUMMARY 5 Workshop Purpose and Scope 5 Background and Objectives 5 Workshop Agenda 6 Overview of Lunar Day/Night Environmental Conditions 7 Lessons Learned From Missions That Have Survived Lunar Night 8 Science Perspective 9 Exploration Perspective 10 Evolving Requirements from Survival to Continuous Operations for Science, 11 Exploration, and Commercial Activities Power Generation, Storage and Distribution - State of the Art, Potential 13 Solutions, and Technology Gaps Thermal Management Systems, Strategies, and Component Design Features - 16 State of the Art, Potential Solutions, and Technology Gaps The Economic Business Case for Creating Lunar Infrastructure Services and 18 Lunar Markets International Space University Summer Project “Lunar Night Survival” 20 Open Discussion Summary 21 APPENDIX A: Workshop Organizing Committee and Participants 23 APPENDIX B: Poster Session Participants 28 1 Survive and Operate Through the Lunar Night WORKSHOP REPORT June 2019 EXECUTIVE SUMMARY AND RECOMMENDATIONS The lunar day/night cycle, which at most locations on the Moon, includes fourteen Earth days of continuous sunlight followed by fourteen days of continuous darkness and extreme cold presents one of the most demanding environmental challenge that will be faced in the exploration of the solar system. Due to the lack of a moderating atmosphere, temperatures on the lunar surface can range from as high as +120 C during the day to as low as -180 C during the night. Permanently shadowed regions can be even colder. -
Lunar Motion Motion A
2 Lunar V. Lunar Motion Motion A. The Lunar Calendar Dr. Bill Pezzaglia B. Motion of Moon Updated 2012Oct30 C. Eclipses 3 1. Phases of Moon 4 A. The Lunar Calendar 1) Phases of the Moon 2) The Lunar Month 3) Calendars based on Moon b). Elongation Angle 5 b.2 Elongation Angle & Phase 6 Angle between moon and sun (measured eastward along ecliptic) Elongation Phase Configuration 0º New Conjunction 90º 1st Quarter Quadrature 180º Full Opposition 270º 3rd Quarter Quadrature 1 b.3 Elongation Angle & Phase 7 8 c). Aristarchus 275 BC Measures the elongation angle to be 87º when the moon is at first quarter. Using geometry he determines the sun is 19x further away than the moon. [Actually its 400x further !!] 9 Babylonians (3000 BC) note phases are 7 days apart 10 2. The Lunar Month They invent the 7 day “week” Start week on a) The “Week” “moon day” (Monday!) New Moon First Quarter b) Synodic Month (29.5 days) Time 0 Time 1 week c) Spring and Neap Tides Full Moon Third Quarter New Moon Time 2 weeks Time 3 weeks Time 4 weeks 11 b). Stone Circles 12 b). Synodic Month Stone circles often have 29 stones + 1 xtra one Full Moon to Full Moon off to side. Originally there were 30 “sarson The cycle of stone” in the outer ring of Stonehenge the Moon’s phases takes 29.53 days, or ~4 weeks Babylonians measure some months have 29 days (hollow), some have 30 (full). 2 13 c1). Tidal Forces 14 c). Tides This animation illustrates the origin of tidal forces. -
The Moon and Eclipses
The Moon and Eclipses ASTR 101 September 14, 2018 • Phases of the moon • Lunar month • Solar eclipses • Lunar eclipses • Eclipse seasons 1 Moon in the Sky An image of the Earth and the Moon taken from 1 million miles away. Diameter of Moon is about ¼ of the Earth. www.nasa.gov/feature/goddard/from-a-million-miles-away-nasa-camera-shows-moon-crossing-face-of-earth • Moonlight is reflected sunlight from the lunar surface. Moon reflects about 12% of the sunlight falling on it (ie. Moon’s albedo is 12%). • Dark features visible on the Moon are plains of old lava flows, formed by ancient volcanic eruptions – When Galileo looked at the Moon through his telescope, he thought those were Oceans, so he named them as Marias. – There is no water (or atmosphere) on the Moon, but still they are known as Maria – Through a telescope large number of craters, mountains and other geological features visible. 2 Moon Phases Sunlight Sunlight full moon New moon Sunlight Sunlight Quarter moon Crescent moon • Depending on relative positions of the Earth, the Sun and the Moon we see different amount of the illuminated surface of Moon. 3 Moon Phases first quarter waxing waxing gibbous crescent Orbit of the Moon Sunlight full moon new moon position on the orbit View from the Earth waning waning gibbous last crescent quarter 4 Sun Earthshine Moon light reflected from the Earth Earth in lunar sky is about 50 times brighter than the moon from Earth. “old moon" in the new moon's arms • Night (shadowed) side of the Moon is not completely dark.