Time & Navigation

Astronomy Homework Research Help

Compiled by Gary Agranat

The primary purpose of this page is to give you the astronomical and historical background.

Note: On this page I am not addressing the physical nature of time. This page is about how regular astronomical motions gave us a basis for telling time. And it is about how those motions and understanding geometry gave us a basis to navigate on Earth. For the physical nature of time, you could try links in the Cosmology section.

Contents

• Time & the Calendar
• Grade school level presentations
• Understanding the Astronomy Background
• Historical Development
• Particular Cultures
• Apparent Motion of the Sun
• More Details
• More Links
• Navigation
• Introductory and Basic Level
• Navigation and Astronomy
• Practical Navigation
• Historical

Time & the Calendar

Grade school level presentations

• Time @ Dragonfly children's magazine.
• Eyes on the Sky, Feet on the Ground
  A website for helping teach astronomy for grade school. Contains online activities with background astronomy information. Much of the content relates to time-keeping and astronomy.

• Sunbeams & Sundials
  National Museums Liverpool, UK.
• Journey In Time
  Franklin Institute. History of Telling Time, Sundials, Foucault Pendulum, Mechanical Clocks.
• Center for Science Education @ UC Berkeley Spaec Sciences Lab
• At Home Astronomy
  Has several at-home experiments related to the sun's apparent motion.
• Lawrence Hall of Science: Star Clock
• Welcome to the Universe at the Boston Museum of Science
  The Patterns in the Sky section has directions to make a very simple sundial.

Understanding the Astronomy Background

• Curious About Astronomy -- Timekeeping
  Part of an astronomy information and Q&A website at Cornell University.
• Polaris Project
  Iowa State University. Notes for an introductory online course. The whole course is relevant to the motions of the sky, the calendar and telling time. See the sitemap.
• Astronomy 161: The Solar System Univ. of Tennesee, Knoxville.
• Timekeeping
  A series of pages.
• Nick Strobel's Astronomy Lecture Notes
  See the section Astronomy without a telescope.
• From Stargazers to Starships
  By Dr. David Stern, NASA GSFC. High school level with some math.
• National Maritime Museum UK
  Informational pages and links.
• Timekeeping
• Royal Observatory Greenwich
  Besides its large set of astronomy fact files, there are additional pages about time and the calendar.

Historical Development

• A Walk Through Time, The Evolution of Time Measurement through the Ages
  National Institute of Standards and Technology
• History of Math @ Simon Fraser Univ. Canada
• The Development of Sundials by Helen Lee
• An Overview of Calendars
  Includes pages about the Mayan, Chinese, and Gregorian calendars.
• Project Astro Utah - Artilces of Von Del Chamberlain
  General level articles by a retired planetarium director.
• A Base for Calendar Exploration through Time Bill Hollon. Thank you for writing me.
• Calendars and their History by L. E. Doggett.
• Calendar -- from Eric Weisstein's World of Astronomy
• National Maritime Museum UK.
• Timekeeping
• Sea, Stars and Time online exhibit.
• Royal Observatory Greenwich
• The Engines of Our Ingenuity
  A series of short history of technology stories on a radio program, by John Lienhard. University of Houston's College of Engineering.
• No. 2134 Time in the Revolution
  About the attempt to change the calendar during the French Revolution.
• No. 1535 Inventing the Clock
• No. 1506 The First Mechanical Clocks
• No. 1307 The Pendulum Clock
• No. 993 Sundails
• No. 72 The First Clocks
• A History of Astronomy by Anton Pannekoek. 1961. Dover.
• Also see the History of Astronomy section.
• Also see Navigation History below, especially for several in-depth websites about the Astrolabe.

Particular Cultures

• The Nile, the Moon and Sirius - The Ancient Egyptian Calendar
  By Richard Weninger. Egyptian Ministry of Tourism.
• Ancient Egypt The British Museum.
  Includes a story about time and the calendar.
• Cultural Online Learning Organization and Resource, History of Mathematics in Asia
• Chinese Calendar
• The South Asian Calendar
• China the Beautiful: Chinese Astronomy
• Introduction to the Chinese Calendar
• Chinese Astronomy by S.Y. Ho
  How did the Chinese determine the seasons?
• Sundials in China - A brief note
  By Prof. K.P.Cheung at the Dept. of Architecture, University of Hong Kong. Part of his section on solar architecture research, which includes some more about sundials.
• The Lunar Calendar in Japan @ Astronomy in Japan
• Land Use History of the Colorado Plateau Home Page
• A Primer on the Evolution of Astronomical Calendars by Brian C. Bates.
  Briefly discusses developments in several ancient cultures.
• Archaeoastronomy in the American Southwest by Brian C. Bates.
• Ancient Astronomers of North America
  By John A. Blackwell. Regulus Astronomy Newsletter.
• The Solstice Project
  The Sun Dagger of the ancient Pueblo Indians of the American Southwest.
• Julius Caesar and Leap Days Astronomy Picture of the Day, February 29, 2000.
• The Gregorian Calendar The Galileo Project at Rice University.

Apparent Motion of the Sun

• Tim Osborn's sun clock
  Climate Research Unit, Univeristy of East Anglia.
• Sun Moon and Earth Applet
  Computes and displays sun and moon position in the sky. Also background information on making such calculations. By J. Giesen.
• Ephemeris.Com
• Analemma
• Sundials
  NASA Liftoff, NASA MSFC.
• Sunbeams & Sundials
  National Museums Liverpool, UK.
• The Development of Sundials by Helen Lee at the History of Math @ Simon Fraser Univ. Canada
• Me and My Shadow -- Making the Sun-Earth Connection about sundials and related science.
  Walter Sanford, Sandburg Planetarium, Fairfax County Public Schools. Many pages of projects and background information.
• Sonnenuhren (Sundials)
  Includes a nice collection of various sundials.
• Sundials on the Internet
• North American Sundial Society
• Cross link to Observing the Sky page.
• Cross link to the Sun page.

More Details

• US Naval Observatory Astronomical Applications Department
• Time Service Dept.
• History
• Rick Fisher, NRAO.
  The context for these pages is the accurate pointing of radio telescopes.
• Definitions of Astronomical Times
• Earth Rotation and Equatorial Coordinates
• The Munich Astro Archive: Scholar (Germany):
• Astronomical Calendars by Dirk Husfeld
• Astronomical Time Keeping by Dirk Husfeld
• Leap Years and Our Calendar @ IPS (Australia)
• Frequently Asked Questions about Calendars by Claus Tøndering.
• The Event Inventor by Kye's World
  Easy to do astronomy projects with some background information. By Kye Ewing.
• Friesian Society, Philosophy of Science Papers
  Papers on calendars of several cultures through history.

More Links

• Links: History of Astronomy: Items: Calendars, Time and Chronology
• Links: Today's Calendar and Clock Page
• Heavenly Mathematics by Helmer Aslaksen. Thank you for writing me.
• Also see Understanding Celestial Coordianates, Charts and Apparent Motions across the Sky and Sky Charts & Calendars.
• Also see the History of Astronomy section.
• The Development of Instruments

Navigation

Introductory and Basic Level

• Deutsches Museum - Marine Navigation
• Eyes on the Sky, Feet on the Ground
  School level. Harvard.
• Maps & Mapping
• The Mathematics of Cartography
  By Cynthia Lanius, Rice University. Basic school level introduction with a little math.
• The Geometry of the Sphere
  By John C. Polking, Rice University
• Navigation: Finding the Way
  Introduction for Children. Dragonfly children's magazine.

Navigation and Astronomy

• Amtsgymnasieti i Sønderborg -- a High School Astronomy Index Page in Denmark
• EAAE - ESA - ESO Sea and Space
  This is about navigation, with some historical background and some nice mathematical thought problems. This webpage can be a useful starting point for astronomy students.
• What is local noon? Information about gnomons, sundials and related matters.
  European Southern Observatory. Part of an information set for student projects (EAAE Astronomy On Line). The Danish high school project above is related to this.
• Nick Strobel's Astronomy Lecture Notes
  See the section Astronomy without a telescope.
• Experiments in Astronomy for Amateurs. By Richard Knox. New York: St. Martin's Press. 1976.
  This book has some wonderful projects to try. Many of them you can make out of cardboard or out of something more durable. Projects include various types of sundials and a calculator for observing the Moon. Spending some time with these projects can help you bridge the practical applications to the underlying science and math. If you take a celestial navigation course, you may notice you are in fact applying the same math, just solving for different unknowns.

Practical Navigation

• Celestial Navigation Net
  A nicely made website with pointers to books and links, with some discussion of the background. Thank you for writing me.
• Navigational Instruments
• Advanced Coastal Navigation Course
  A practical online course. Thank you for writing me.
• Astronavigation Introduction
  ESYS, das Europäische Segel-Informations System. In German.
• Navigator Light
  This has a shareware program for determining your position from sextant readings. The website includes an online almanac and some easy-to-read notes about celestial navigation with a sextant:
• Nautical Almanac
• Celestial Navigation
• HM Nautical Almanac Office
• Astronomical Applications Data Services
  Reference at U.S. Naval Observatory
• Web MICA Nautical Almanac
• Celestial Navigation Data
• GPS and never having to say: 'Where am I?' NOVA Science Australia.
• Beyond Discovery- The Global Positioning System- The Role of Atomic Clocks
• Magnetic Declination (Variation)
  NOAA National Geophysical Data Center.

Historical

• Sailing the Ocean Without Map or Compass: Traditional Navigation in the Western Pacific
  University of Pennsylvania Museum of Archaeology and Anthropology.
• Wayfinders
  PBS program about Polynesian navigation.
• Magnetic Compass, China, 220 BCE
  Smith College Museum of Ancient Inventions.
• Museum of the History of Science Oxford.
• MHS Astrolabe Home Page
  As of this writing, this website is still under development. Looks like it will be quite extensive. Besides illustrating the museum's collection, the website has an in-depth guide for how the astrolabe was used.
• Astrolabes of Africa
• Epact Scientific Instruments of Medieval and Renaissance Europe
  Almost two dozen informative articles on specific types of instruments and over 500 images. Also has a glossary.
• Also check Sphaera the musuem's newsletter from 1995 to 2000 for short articles.
• The Astrolabe by James E. Morrison
• The Astrolabe by Gary Agranat and Dave Delligati
• The History of the Sextant by Peter Ifland.
  In Helios, Observatório Astronómico da Universidade de Coimbra, Portugal.
• Latitude -- The Art and Science of Fifteenth-Century Navigation
• The Columbus Navigation Homepage Keith A. Pickering
• Includes Columbus and Celestial Navigation
• The Galileo Project Homepage
• Longitude at Sea
• History of Mathematics @ Mac Tutor:
• Longitude and the Académie Royale
• The English Attack on the Longitude Problem
• NOVA Online | Lost at Sea: The Search for Longitude
  PBS NOVA program, October 6, 1998.
• European Voyages of Exploration University of Calgary.
• Technical Advances in Shipbuilding and Navigation
• National Maritime Museum UK.
• PORT - Maritime Information Gateway
  National Maritime Museum. Browse the Navigation section.
• BBC - History
• BBC - History - A History of Navigation
• Map History / History of Cartography
• Astronomía y Navegación a Bordo del H.M.S. Beagle
  Ciencia al Día Internacional - Artículo 4 Tecnolgía (Chile).
• The Age of Explorations
  Short pages about the historical background, from ancient times onwards. Limited information about the navigation techniques. The Mariners' Museum Newport News, Virginia
• Discoverers Web Pages
  Extensive links compiled by Andre Engels.
• Ancient World Mapping Center
  Interdisciplinary research center at University of North Carolina at Chapel Hill. The website reviews and links to many resources on the Internet.

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Astronomy: Time & Navigation / Gary's Astronomy Homework Research Help /
members.aol.com/gca7sky/time.htm
/ Created November 3, 1997. Revised August 29, 2006. Last updated September 30, 2006.
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