8-12 Lesson 5

Sunrise...Sunset - Bilingual Telemation Unit

8-12 Lesson 5:
Sun Calendar and Crop Planting

Concept:

Observations of the sun can be made that can determine the best time to plant crops.

The Scientific Investigation:

How can simple observations and tools be made that can link the apparent motion of the sun to the cycle of planting and harvesting crops?

Purpose:

Student will map the sun's location along the horizon. They will devise a sun calendar showing preferred planting time.

Materials:

Per class or lab group:

Long tube at least 3 cm diameter - such as a gift wrap tube
Mirror (mirror tiles work well)
Box
Duct tape
Paper

Per lab group:

Two clear plastic sheets - such as overhead transparencies
Overhead projector pen
Tape
White unlined paper

Procedure:

Locate a window with a view of the eastern horizon.
After students read background information(Spanish), use the tube and the mirror to demonstrate the observatory shafts. You will need a sun-facing window. Caution the students never to look through the tube at the sun, nor to look at its mirror reflection (the paper reflection is fine).
Lab groups will tape their plastic to the window and trace the outline of the horizon. Afterwards they will use their tracing to recopy on white paper.
Once a week at sunrise, mark the location of the sun. Students can copy the location onto their own sheets when they come to class. Or you may wish to have the students do this activity at home.
Using information from Sunset Western Gardening or other garden book, have students research planting time of cilantro, corn, beans, and radishes.
When the sun calendars are complete, students can outline preferred planting times on their pictures of the horizon.

Assessment:

Scientists work in a very methodical fashion. Maintaining accurate records of observations and measurements is a key component in this systematic method. Every student should keep accurate chronological records, possibly in a scientific investigation journal or science lab book, of everything done in the investigation. These notes should be placed within each student's portfolio for assessment purposes.

Resources for basic information are essential to scientific investigations. Many of these resources are available to the general public and contain lots of information on a variety of subjects. The U. S. Geological Survey, Food and Drug Administration, National Institutes of Health, National Institute of Mental Health, and others contain a wealth of basic information.

In many ways the weather page is a one page microcosm of some of the kinds of information contained in these more basic research resources. What information did the student find useful which was in common with students in other schools cooperating in investigations? The students should include documentation of the type of information which they have found useful on the weather page in their portfolio.

Assessment of the quality of the student's work should respond to a rubric. This assessment tool describes how the level of involvement and completeness of a student's work will be related to the evaluation he/she will receive for the portfolio. Refer to a sample of a rubric included at the conclusion of these lessons.

Conclusion:

How does the position of the sun at sunrise and sunset relate to the appropriate time to plant various food crops? How did various diverse cultural groups in the past develop calendars so they could predict when these important activities happen? Does our current calendar reflect these important relationships between crop planting schedules and the position of the sun in our sky?

Extensions

Mathematics:

Developing calendars and maps involves the developing of pictorial, graphic and chart representations of nature. Students need to understand why they are valid representations of nature. What mathematical notions are involved in making maps useful representations of expansive geographical areas and calendars useful extensions into the future of time and our daily routines? Mathematics has evolved largely from a need which people have had for developing a symbolic representation for something which is too bulky or dangerous to deal safely with on a regular basis. Why was money developed to represent the actual trading of real items?

Language Arts:

Communication between the participants in this investigation who reside in different schools and are far removed from one another will be through the transmission of text files using the medium of telecommuciations. Students should prepare their messages in a word processor, making corrections as necessary to clarify what they wish to send to others who are working with them on the project. The word processing file should then be saved as an ASCII file, up-loaded, and sent within the time frame of the project's schedule.

Language Development Strategies:

Communication via telecomputing requires the use of written statements. One important advantage of using computers to communicate with one another is that "what you read is all that you know." Students will be encouraged to ask people to clarify their written messages when they are not clearly communicating ideas to the other party. Through these feed-back techniques, students will learn how to more effectively and clearly communicate with people with whom you are not directly able to explain yourself and your message as people are able to do in person or on the telephone.

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