| Objectives
I encourage my students to be careful observers. They use their observations
to make models, graphs, and further inquiries. This approach helps my
students develop a positive attitude toward Science. Throughout the
year my science units use this philosophy of learning. The unit described
here is a very successful year-long project concerning the Earth/Sun
relationship.
Approach
Our Science textbook lacks the quality that leads students to understand
the relationship between the Sun and Earth. The drawings and photos
don’t allow students opportunities to deeply understand this complicated
relationship. My approach in this project has multiple dimensions.
Observation and Measurement
Daily my students can check the time bystanding on a human sundial.
This helps students understand the relationship of the sun’s
position and the time of day.
Monthly my class measures the sun’s height at noon. We measure
(in degrees) the length of a stick’s shadow in relation to its
height.
Models
A special clock models the Earth’s rotation and tilt. It helps
students understand how we get days and seasons.
Monthly the sun’s path is recorded on a model of the sky. Students
place markers on a cleardome to show where the sun rises and sets.
They mark the sun’s altitude at noon. Using these measurements,
we draw the arc the sun makes across the sky.
Birthdays remind students that they made one revolution (while riding
on the Earth) around the sun for each year of their life. Students
carry the globe counterclockwise around a sun model once for each
year celebrated.
I take the students in a portable planetarium where we:
• model the sun’s monthly path across
 the
sky.
• measure the time it takes for the sun
to
sweep across the sky
• mark points on the horizon where
the
sun rises and sets.
• observe the sun’s altitude at its
highest
point.
Graphs and Charts
We graph the amount of daylight and darkness we receive monthly. The
graph demonstrates how daylight decreases before and increases after
Winter Solstice.
We graph the sun’s altitude, which helps us understand the sun’s
lowering altitude before and rising altitude after Winter Solstice.
Explanation and Extension Questions:
We compare the sun’s affect at various latitudes by e-mailing
students in Norway. We share our observations and inquire about their
observations. We use internet sites (such as Google Earth) to help
us communicate our location and to locate them)
We take our sunrise/sunset graph one step further and make graphs
of other countries—one near the equator and one near the North
Pole.
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Relevance
This project uses science, technology and math to explain the relationship
of the sun and Earth. Students make connections between our experiences
and those of people living in other parts of the world. These difficult
concepts are realized as we make and interpret models and graphs to
represent our observations and measurements. Learning to observe and
analyze information helps students develop a deeper understanding of
the world—important skills for scientific and technical careers.
Measurement
Observing my students reveals great increases in their knowledge of
the Earth/sun relationship. Students use our globe/clock to check the
time in Norway and make accurate observations about the length of day.
Their predictions for future months are becoming more accurate as the
year progresses.
Written tests verify that my objectives are being met. 93% of my students
have mastered the concept of the effect of Earth’s rotation and
revolution. So far this year, 79% of my students show an understanding
of our latitude affecting the amount of daylight and darkness we receive.
Since we are less than half way through the year, this number will increase
as we continue to work on this concept.
These results are reinforced by an annual standardized test. My students
achieved 80% on a question about Earth’s rotation affecting the
length of day. Students from the rest of our school, district, and state
scored considerably lower.
Student surveys show most students enjoy Science more when they make
their own observations and conclusions.
Challenges
It took years to develop materials used for this project—constructing
charts, finding a dome for the sun path model, construction of the human
sundial, finding pen-pals from a country far enough North to fill our
needs.
To construct the sun path dome, I bought a sock bin from a shoe store.
I turned the bin upside down to create a clear dome, representing the
sky. I decorated the dome with horizon and measuring scales to allow
us to accurately mark the sun’s altitude and azimuth. It works
great and provides excellent conversation between students and parents.
To construct the human sundial behind our school, I found a boy scout
(a former student) who was looking for an Eagle Scout project. He liked
the idea of building the human sundial for his former elementary school
and took on the project. It turned out fantastic and is frequently used
by students.
Weather sometimes causes an obstacle. During inclement weather we
retrieve information about the sun’s altitude and azimuth from
the internet.
Time constraints are always an obstacle. With 5 subjects to teach
daily, it is not easy to cover everything in a timely manner.
Communicating with students in Norway was a problem. We found a school
that teaches English as a second language. They were happy to communicate
with us. We also learn a little of their language. |
