8-12 Lesson 4

Sunrise...Sunset - Bilingual Telemation Unit

8-12 Lesson 4:
Reason for Seasons

Lesson 4 - 6: Teacher's Guide for Astronomy and Agriculture

Concept:

Seasons on the earth are due to the tilt of the earth's axis. In the winter the sun's radiation is spread out over a larger surface area of the earth. In the summer the energy is concentrated in a smaller area.

The Scientific Investigation:

How does the orientation of the earth towards the sun determine the seasons?

Purpose:

Students will understand seasonal temperature change by two activities-a solar hot water experiment and a model of the Earth and sun using a light bulb and a styrofoam ball.

Materials:

Per Lab Group:

Three metal containers with different surface areas (different size disposable aluminum pans work well)

Tape

Plastic wrap - enough to cover each pan

Three Celsius thermometers

Watch or clock with second hand

Metric ruler

Per Student:

Student worksheet "Reasons for Seasons" (Spanish)

3 inch Styrofoam ball with pencil or dowel

Thumbtack

Per Class:

100 watt light bulb

Socket

Globe

Procedures:

Day One (1 of 2) (IMPORTANT: Do not do on a cold day.)

Have students answer hypothesis in worksheet.
After students have a chance to read the procedure, review lab instructions and pass out lab materials to each lab group.
After students have completed the lab, they should complete the two line graphs and explanations.

Day Two (2 of 2)

After passing out styrofoam balls, assist students in finding the proper location for their thumbtack by showing them with a globe.
Have students stand in a circle around the light bulb. Review the procedure and darken the room.
Students should complete the questions and the analysis.

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 intensity of light affect the changes in temperature in a substance? How does the distance of the light bulb from the surface of an object affect these changes in temperature? How does changing the "power" of the bulb affect the changes in temperature (25 watt bulb versus 100 watts)? How does the angle of the surface with respect to the "incident" rays of light from the bulb affect changes in the temperature? What relationship does this model situation have to the real changes which we experience in nature as the seasons progress?

Extensions:

Mathematics:

Reporting data from an experiment involves interpreting how much information you want to communicate with numbers you "post." The term significant figures has very important implications in mathematics. How much certainty do you wish to communicate in your data? How does this "certainty" or "uncertainty" work itself into mathematics which you then do with the numbers which you have used to describe a situation?

Many activities can be used to illustrate this important idea to students. A few are included below:

What is the age of a typical person in the classroom? (Let the class struggle with the issues of how to represent age...years... months...days...etc.)
How tall is the "average" person in class? (Let the class work out the issues of how to combine information on males and females.)
What's the temperature in the classroom? (This issue gets more complicated when the students discover that the temperature is different near the ceiling compared to the floor, and different near the door, compared to near a remote corner of the room.)

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 them 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 they are not directly able to explain themselves and their message as people are able to do in person or on the telephone.

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