By Jay D. Dunn
University of Idaho

ITV Series: Bill Nye the Science Guy BNSG 121 G

wpe4.jpg (2992 bytes)This lesson uses segments of a Bill Nye video to help students understand the basic principals of seasonal change. The Bill Nye video offers an entertaining and informative look at planetary motion and angle of incidence as they relate to differential heating of the earth's surface. Many of the activities performed on the show are thoroughly explained and demonstrated, making it very easy to duplicate them at home or in the classroom.

During this lesson students are first presented with simple observations about seasonal change. They are then given time to ponder the mechanisms that drive these changes. Later, they will perform experiments that show what causes the earth to heat differently during different seasons. Students will be asked to analyze the results of these experiments and apply them to what they know from their daily observations.

Learning Objectives

Students will be able to:

  • Identify the differential heating of the Northern and Southern hemispheres.
  • Describe the changes in surface heat caused by a change in angle.
  • Describe the position of the earth relative to the sun during each season.
  • Explain the theory behind Foucault's Pendulum.
  • Identify the Earth's angle relative to the plane of elliptic.
  • Describe the Earth's orbit around the sun.


  • Juice can lids
  • Black paint
  • Flash lights
  • Globes
  • Bowling ball
  • Cable
  • Newspapers with weather reports
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Focus for Viewing

To give students a specific responsibility while viewing begin by referring back to the pre-viewing activity. Inform them that the video will help them understand the mechanisms that drive the seasonal changes. For those that are inherently curious, this should be a good incentive to keep their focus.

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Pre Viewing Activities

Divide the class in several groups. Have each group brainstorm about the changes in seasons. Guide them to think about times of the year, temperature, sun angle, etc. Next give each group a weather report from a newspaper. It would be best if the reports were from different times of the year. Have the groups analyze the weather conditions from the newspapers and write short reports about their findings. At the end of class a representative from each group can give a summary of the findings. Challenge the class to think more about the results for the next day.

Viewing Activities

BEGIN playing the Bill Nye video at the beginning. PAUSE the video when Bill Nye says "It's winter in places like South America and Australia." Have the class think about the research that they have done with the newspapers. See if they can apply what they know already to the question asked on the video.

RESUME video and STOP the video when Bill Nye says "the one in the north slowed way down." Once again, have the class discuss the possible reasons for the two solar powered motors running at different speeds. At this point bring out the flashlights and globes for an experiment.

In small groups the students will experiment with the differential light intensity on the Earth's surface. With the lights turned down one student will hold the globe at approximately 23 degrees from perpendicular. One other student will shine a flashlight from the side at a distance of 6 to 8 feet. The others in the group will make observations about the differences in the light received by each hemisphere. The globe must have the light shine on it from four sides, 90 degrees apart.  Have the groups discuss their observations and compare with other groups. RESUME playing the video the next day.

PAUSE the video when the boy on the tape says "turn on the light and wait a few minutes." The class can discuss the experiment and make some guesses about possible results. When they come to their conclusions, present them with black juice can lids to put under a lamp. One lid must be flat, another at an angle, and the third propped upright. Have the groups expose their sets of lids to the light. They will find out that the lid that was flat will absorb the most heat.

RESUME playing video and PAUSE the video when Bill Nye asks, " would you do it?" Once again, the class will brainstorm a possible way to show that the Earth is spinning. Each group will diagram their method for proving that the Earth is spinning. When they come up with some ideas, have them share between groups.

RESUME playing video and PAUSE the video when Bill Nye says, "...keeps spinning in the same direction as the Earth turns under it."  Now with a little more knowledge about the motion of objects, the groups will try again to figure out a way to measure the Earth's rotation.

RESUME playing video and STOP the video when Bill Nye says "thank you for joining me on Consider the Following." In the time remaining in the class period discuss the possibility of construction a model of Foucault's Pendulum. Have the students consider the latitude of their location and the possibility of that having an effect on the experiment.

Post Viewing Activities

This activity is to construct a model of Foucault's Pendulum, observe it in action and report on these observations. According to the example given on the video, the teacher must construct the pendulum. It will take some time at home or after school to fabricate the device.

The day following the last segment of the video, have the pendulum in place prior to class. Begin the class period by reviewing the purpose for using Foucault's Pendulum. Next, set the pendulum in motion, start a timer and mark the path of the weight. After the pendulum has been in motion for exactly half an hour, mark the new path of the weight.  Measure the angle of change and compare with student predictions.


To follow up on the video and experiments, the students will utilize the Internet to find information relevant to the assignment. This information may include characteristics of the Earth's orbit/rotations or weather data. When each student has found a web site and is familiar with it, have them write a short essay on their findings. Next, form the same groups so that they can compile their work, including all segments of the lesson, and submit it as a portfolio for the group.

From the measurements taken during the pendulum experiment, calculate the movement over a twenty-four-hour period. Would it turn 360 degrees? If not what may be the reason.

Explore the weather patterns in different parts of the world including the Southern Hemisphere. Make association with latitude, elevation, and surface material. Are there any patterns?

For additional lesson plans and ideas relating to this topic and many others try TeacherSource!   You will find activities, lesson plans, teacher guides and links to other great educational web sites!  Search the database by keyword, grade level or subject area! 

Mathline and Scienceline are also great resources for teachers seeking teaching tips, lesson plans, assessment methods, professional development, and much more!  Look for a localized version of Mathline and Scienceline on IdahoPTV next year!

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