Summary
Activities in this lesson help students understand the reasons for the seasons.
Materials
Additional Resources
Books
The Seasons of Arnold's Apple Tree, by Gail Gibbons, ISBN 0-15-271246-1
Sun Up, Sun Down, by Gail Gibbons, ISBN 0-15-282782-x
The Reasons for Seasons, by Gail Gibbons, ISBN 0823411745
The Little Island, by Golden MacDonald and Leonard Weisgard, ISBN 0-440-40830-x
Sunshine Makes the Seasons, by Franklyn M. Branley and Michael Rex, ISBN 069004481X
The Real Reasons for Seasons, Great Explorations in Math and Science (GEMS), ISBN 0-
924886-45-5
Media
Bill Nye the Science Guy. Earth's Seasons; ISBN 1932644342 9781932644340
Organizations
Activities Integrating Mathematics and Science (AIMS)
http://www.aimsedu.org/
Background for Teachers
There are many misconceptions about what causes seasons. When
people think about Earth's revolution around the sun, many picture
a very oval, elliptical shape. Earth's orbit is a slightly elliptical circle.
However, the distance between the sun and Earth does not change
significantly throughout the year.
Because of Earth's tilt and revolution around the sun, each of
Earth's poles tilt toward the sun for part of the year. Consequently,
each pole is tilted away from the sun for part of the year. When
the Northern Hemisphere is tilted towards the sun, the result is
more hours of daylight and more direct, intensified sunlight for our
hemisphere. Direct light causes higher temperatures than indirect
light. When our hemisphere is tilted away from the sun during winter,
the angled sunlight is spread over a greater area, resulting in less
intense heat.
Intended Learning Outcomes
1. Use science process and thinking skills.
2. Manifest scientific attitudes and interests.
3. Communicate effectively using science language and reasoning.
Instructional Procedures
Invitation to Learn
- The ancient civilization of Greece explained the seasons in
a very different way than modern scientists do today. First
students will participate in a reader's theater in which the
Greek gods tell the story of Demeter and her beautiful
daughter, Persephone. The myth tells of the dark god, Hades,
kidnapping Persephone and taking her to the underworld to
live as his wife. When Demeter hears of her daughter's fate, she
mourns so violently that Earth begins to whither and die. It is
only upon Persephone's return that Earth blooms to life again.
Tell students to pay close attention to how the Ancient Greeks
explained the reasons for seasons while reading the myth.
- Tell students that scientists today explain the reason for Earth's
seasons in a very different way than the Ancient Greeks did.
Provide each student with an index card. Ask students to
write what they know (or think they know) about the scientific
explanation for seasons on their card. Collect cards and post
them on a board that compares accurate scientific information
with misconceptions. Students should compare and contrast
the Ancient Greek ideas, common modern-day misconceptions,
and the real reasons for seasons throughout the unit. Concepts
should be reviewed and updated as knowledge grows, changes,
and clarifies.
Instructional Procedures
Activity One: Activating Background Knowledge
- As a quick, cooperative learning activity, activate students' prior
knowledge on the concept of seasons, temperature, and seasonal
connections to the students' world. Students should work in
small groups to complete the following Seasons Brainstorming
Chart: (Charts should be cut out and placed into science
journals.)
Seasons |
Average
Temperature
|
Signs in Nature
|
People's
Activities
|
Winter |
|
|
|
Spring |
|
|
|
Fall |
|
|
|
Summer |
|
|
|
Activity Two: Sunray Catchers
- Explain to students that they will be gathering information
to explain the real reasons for seasons by collecting detailed
temperature data. (This activity should be done outside on a
day with little cloud cover to see the most dramatic results.)
- Allow a short amount of time for students to practice reading
the thermometers, holding steadily at eye level and not
obstructing the bulb with their fingers. Have students examine
the scale used on the thermometers. Ask each group of
students to stand in a different area of your classroom and
report the accurate temperature. Just as the temperatures
within your classroom will differ slightly because of exposure to
heat sources and movement, so does the temperature on Earth.
In order for students to see accurate results, first calibrate all
the thermometers by placing them in ice water for 5 minutes.
Students will be able to see the thermometer rise significantly
when they move the thermometer to their specified location.
Construction of Sunray Tool
- Explain to the students that they are going to construct a
sunray-gathering tool to help model one reason for the seasons.
Construct the sunray-gathering
tool with students in groups of
three or four.
- Begin by cutting a piece of
Styrofoam about 12 inches square
for each group. (This board will
be reused in a subsequent lesson.)
- Now, groups are going to
construct holders for the 4
thermometers. Each group will be
given a 12" x 18" piece of art paper that has previously been cut
in half lengthwise so that it measures 6" x 18". Have students
fold their paper in half, and in half again, creating four equal
sections that are 41⁄2" x 6". Cut pieces apart. Then, students
should fold each piece in half and glue the outer edges, creating
a pocket to hold a thermometer. Finally, have the students label
the pockets: 0 degrees, 30 degrees, 60 degrees, and 90 degrees.
- Tape a skewer to the back of each pocket. The top of the skewer
should line up with the top of the pocket.
- Place a protractor on the horizontal edge of the Styrofoam.
Measure with the protractor and push the 30, 60, and 90-
degree skewers into the tag board at the correct angle. Slip a
thermometer into each pocket, making sure each thermometer
bulb is covered. Rest the fourth skewer (0 degrees) on the
Styrofoam and use a small piece of tape to hold in place.
Experimenting with the Sunray Catchers
- Have the students take their ray-catcher, science journal, Sunray
Data Collection Sheet, four different colored pencils, and the line
graphing paper outside and choose a location exposed to the
sun. Each student group should choose a different location.
- Students will wait 10 minutes. While students are waiting
have them record the procedure for construction of the sunray
catcher and their hypothesis for this ray-catching experiment in
their science journal.
- After 10 minutes, making sure to keep the bulb covered,
students will slide the thermometer out of the holder enough
to read it at eye level. Record the temperatures on the data
collection chart. Wait and record the temperatures two more
times. As students are waiting to read the thermometers at the
stated intervals, they should create a four-line graph on the
sunray line graphing paper demonstrating the data they are
collecting. Use a separate color for each angle. Label the graph
key. Students should record any trends or conclusions they
observe in their science journals.
- When students return to the classroom, have students use
calculators to determine the average temperature for each
thermometer. Have the students discuss their findings
and observations in small groups and then with the whole
group. Discuss the trend shown in the data collected. (The
temperature increases as the directness of sunlight increases.)
- Students will finalize findings by creating a bar graph of the
averaged data on the sunray bar graphing paper.
- Instruct students to journal in their science notebooks about
today's experiment. What was the experiment? (How does
the angle of the sun's rays affect temperature?) What was the
variable in our experiment? (The angles of the thermometers.)
Sketch a model of the experiment. Write a conclusion based
on direct and indirect sunrays based upon today's experiment.
(More direct light equals more heat; less direct light equals less
heat.) What are the limitations of the model we used? (It is
not done to scale; we only used four sun angles, etc.)
Activity Three: Putting a Spotlight on Seasons
- Do a quick demonstration on the concept of direct and indirect
rays by shining a flashlight with a bright, concentrated beam
at your classroom globe. Hold the flashlight at a 90-degree
angle and have students describe the shape of the light they see
shining on the globe. How would students describe these light
rays? (Direct light) Hold the flashlight at approximate 60 and
30-degree angles and have students notice how the shape of the
light changes. How would students describe these light rays?
(Indirect light) Ask students to infer: What would happen to
the heat of the sun's rays if they were spread over a larger area?
(The heat would be less intense as it spread out.)
- Have students work in pairs or small groups to compare the
area of direct and indirect light. First, students shine light from
a flashlight directly onto the centimeter graph paper from 10
centimeters above the paper. One student holds the flashlight
as the other student traces around the beam of light shining
onto the paper. Students count the squares on the grid paper
and estimate the area of the light ray. Then, using a protractor,
tilt the flashlight to a 60-degree angle. Make sure the flashlight
remains at a constant height above the paper (10 centimeters).
Students should trace the light on the paper, and estimate the
area. Repeat procedure with a 30-degree angle.
- Last, students should discuss the findings of the spotlight
activity with their partner. Ask students to connect this activity
with our previous sunray experiment. What do both models
show? (Direct and indirect light) Students should write their
findings and connections into their science journals.
Extensions
Curriculum Extensions/Adaptations/
Integration
- For advanced learners, allow them to design their own
experiment to show the direct and indirect angle of the sun's
rays. How would they change or improve the experiment
we did in class? Pose this question: How would the seasons
change if Earth were NOT tilted on an axis? What would the
results of our experiment be if we collected data in the morning,
at noon, and near the end of school?
- For learners with special needs, have them take a picture or
draw the sunray collection board. Label each thermometer in
the picture with the comparative adjectives: warm, warmer,
hot, hotter.
Family Connections
- Students and their families should observe the location of the
sun throughout the day. Compare the temperatures during the
morning, daytime, evening, and night. Where did they notice
the sun in the sky during those times?
- Students practice fluency by reading the seasons information to
their family.
- Students collect an index card from at least one adult with the
adult's explanation of why the earth has seasons. The students
should sort and post these cards onto the compare/contrast
board showing accurate information and misconceptions.
Assessment Plan
- Instruct students to write on an index card how direct and
indirect rays correspond to temperature. These cards should
be posted on the compare/contrast board to add to students'
understanding of the reasons for seasons.
- Sketch a picture of Earth. Draw the rays hitting the equator
directly, and continue drawing sunrays showing the curving of
sunlight around the North and South Poles. Notice how short
and direct the rays are those strikes at Earth's equator compared
to the rays that are longer and must curve when they strike
Earth near its poles.
Bibliography
McCoy, J. D., & Ketterlin-Geller, R., (2004). Rethinking instructional delivery for diverse
student populations: Serving all learners with concept-based instruction. Intervention in
School & Clinic, 40.2, pp. 88-95.
Science issues are a part of our everyday world, but what commonly
happens with the teaching of science is students are smothered in
abstract and highly theoretical science content. Teachers need to
focus on teaching the big essential ideas and concepts, rather than
teaching minute details and memorizing facts to regurgitate on a test.
One method of doing this is by using hands-on activities that are
modeled after real life situations. This helps students focus on concrete
applicable science that is interesting and relevant. Another method
is simple, inexpensive labs and activities that require little specialized
equipment, but focus on key models or experiments that illuminate
specific scientific content. This gives students access to the curriculum
in a meaningful way.