The basic concept of time is really based upon two very specific movements of the Earth: its rotation on its axis, and its revolution, or orbit, around the sun. Astronomers stationed at the observatory at Greenwich, England, set the world's atomic clock by the noonday sun. When the sun has reached its zenith -- or, as it is sometimes known, the sun's meridian -- it is exactly noon.
Ancient navigators, however, found it very difficult to know their exact location once they were out of sight of land. It was not until 1714 that a clockmaker, John Harrison, came to realize that exact time away from the home port could be calculated using the measurement of longitude with a starting point of the Prime Meridian. From that, ship's captains could determine their exact location at sea.
This lesson, supported by hands-on activities, video, and Internet connections will examine our reliance on latitude and longitude, not only to give us our location on maps, but our connection to time and time zones. Students will explore some of the trials John Harrison made to invent a reliable method of determining longitude on a ship at sea by understanding pendulums, practice finding the location of cities across the world by using an interactive Web site, and figure out the world's time and the value of time zones the world over. This lesson will also use the format of the Embedded Assessment to ensure student understanding of the concepts taught.
Students will be able to:
- Understand the basic concept of time through an understanding of rotation and revolution
- Calculate longitude and time based on a starting point of 00 longitude, the Prime Meridian
- Determine the latitude and longitude of cities around the world
- Contextualize how the terms A.M. and P.M. came into use
- Visualize the sun's path by means of a bulletin board display
- Orally explain log and line and their use in determining a ship's speed
Learning Standards for Social Studies at Three Levels - New York State Education Department
Standard 3: Geography
Students will use a variety of intellectual skills to demonstrate their understanding of the geography of the interdependent world in which we live -- local, national and global -- including distribution of people, places and environments over the Earth's surface.
Standard 3: Mathematics
Students will understand mathematics and become mathematically confident by communicating and reasoning mathematically, by applying mathematics in real-world settings, and by solving problems through the integrated study of number systems, geometry, algebra, data analysis, probability, and trigonometry.
Standard 4: Science
Students will understand and apply scientific concepts, principles, and theories pertaining to the physical setting and living environment and recognize the historical development of ideas in science.
Standard 7: Interdisciplinary Problem Solving
Students will apply the knowledge and thinking skills of mathematics, science, and technology to address real-life problems and make informed decisions.
National Science Standards: 5-8
Design and Conduct a Scientific Investigation
Students should develop general abilities, such as systematic observation, making accurate measurements, and identifying and controlling variables.
Use Appropriate Tools and Techniques to Gather, Analyze, and Interpret Data
The use of tools and techniques, including mathematics, will be guided by the question asked and the investigations students design. Students should be able to access, gather, store, retrieve, and organize data, using hardware and software designed for these purposes.
Nova, "Lost at Sea: The Search for Longitude"
Seasons: Earth's Seasons--Zoom Astronomy
This site details the Earth revolving around the sun in its elliptical orbit. It takes 365 1/4 days for the Earth to complete one revolution and return to its starting place.
Worldtime Interactive Atlas
www.worldtime.com/cgi-bin/wt.cgi?cnt=127621& ID = c91426da5
This interactive site allows students to insert grid lines of latitude and longitude and predict whether a region is in darkness or daylight.
Explore Science.com: Astronomy
www.explorescience.com/activities/activity_list.cfm? Category ID = 7
This multimedia Web site investigates, through a specific activity question, if it really is that difficult to get planets orbiting around a sun. The site allows students to use an Orbit Simulator. This site needs the Shockwave plug-in.
The Chip Log
Using text and pictures, this site details an extremely accurate method for finding your speed on a sailing ship using logs and knotted rope.
Look-up Latitude and Longitude: Astrodienst Atlas
Once you click on the above Web site, look for Query Atlas. The Web site below comes up:
www.asto.com/cgi_bin/atlw3/aq.cgi? Lang = e
This is an interactive Web site that helps you to locate any city/country/place in the world. The site gives the latitude and longitude of the city/country/place.
Per group of 2 students:
- 2 rulers
- 2 pencils
- Copier paper to be shared by all students
- 1 globe
- 1 atlas
- Student data sheets