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Lost at Sea—The Search for Longitude

Classroom Activity

Objective
To research and chart the shortest course to circumnavigate the globe.

• copy of "Voyage Around the World" student handout (HTML)
• world map, globe or atlas, with a scale
• small tacks, pins or self-stick notes (for marking locations)
• a 12-inch piece of string (for measuring distances)

1. Organize students into groups and distribute student handouts and materials to each group. Explain that the challenge is to research and chart a course that takes them to each Checkpoint Destination on their way around the world once. Have students review the Nautical Rules and Checkpoint Destinations before beginning. (You may delete or change Checkpoint Destinations to best suit your students' abilities.)

2. Have students research locations that match the Checkpoint descriptions, plot these locations on a map, record the latitude and longitude for each, and plan their course from one location to the next. Then have them estimate the distance between locations, using the string and a map scale.

3. When teams have completed their routes, have them exchange maps and recording charts to compare Checkpoint locations and estimated distances. Then, as a class, come up with the shortest route possible.

4. As an extension, you can have students convert the estimated distances from statute miles to nautical miles.

Because the Checkpoint Destinations are open-ended, the locations and courses students choose will vary (see sample course below). When students present their locations, courses and estimated distances, they should be able to explain why each location matches the Checkpoint description, how they chose the course, and the method they used for estimating distances. Most maps students will be using show statute miles, the unit of measurement for distances on land. Distances at sea are measured in nautical miles. A nautical mile is found by dividing the Earth into 360 degrees, and then dividing each degree into 60 minutes. One nautical mile equals one minute, or 1/21,600 of the Earth's circumference. Students can convert statute miles to nautical miles by dividing the number of statute miles by 1.1508.

Sample Course

Books

Hobden, Heather, and Mervyn Hobden. John Harrison and the Problem of Longitude. Lincoln, England: Cosmic Elk, 1989.
Includes a history of John Harrison and his invention of the maritime chronometer, which solved the problem of finding longitude at sea.

Sobel, Dava. Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time. New York: Walker, 1995.
Takes the reader back to the maritime world of 1714, when finding the solution to the problem of determining longitude at sea was of the highest scientific, political and economic priority.

Web Sites

NOVA Online—Lost at Sea: The Search for Longitude
http://www.pbs.org/nova/longitude/
Will include an interactive game that provides a way to understand why knowing the time at your home port allows you to fix your longitude at sea. The site will also feature how the Global Positioning System works, a time line of ancient navigation, and contributions from leading experts on what they believe are some of the greatest scientific challenges of our day. Launch date: Currently available.

The "Voyage Around the World" activity aligns with the following National Science Education Standards and Curriculum and Evaluation Standards for School Mathematics:

Grades 5-8

	Science Standard G: History and Nature of Science

Science as a human endeavor

• Science requires different abilities, depending on such factors as the field of study and type of inquiry. Science is very much a human endeavor, and the work of science relies on basic human qualities, such as reasoning, insight, energy, skill and creativity—as well as on scientific habits of mind, such as intellectual honesty, tolerance of ambiguity, skepticism and openness to new ideas.

	Mathematics Standard 7: Computation and Estimation

	Mathematics Standard 13: Measurement

Grades 9-12

	Science Standard G: History and Nature of Science

Science as a human endeavor

• Individuals and teams have contributed and will continue to contribute to the scientific enterprise. Doing science or engineering can be as simple as an individual conducting field studies or as complex as hundreds of people working on a major scientific question or technological problem.