Exploring Direct and Indirect Sunlight
If you conducted Exploring
Seasonal Shadows and Sunlight,
ask, What did your shadow studies reveal about the angle of the
sun at different times of year? What else do you think the
angle of the sun affects as it hits the Earth’s surface?
students’ ideas and have them identify ones they can explore through
direct observations or experiments. If they mention the Earth’s
temperature, ask them to explain their thinking. Ask, How could
we test this idea? Let students pursue their ideas, or suggest
two pie tins black. Set both tins out in the sun. Ask, How
could we simulate the sun's rays hitting one tin at an angle (indirectly)?
They might, for instance, place one lying flat so that the sun
shines directly on it and stand the other one up vertically in
a piece of clay so it receives only angled rays.
students to predict which they think will absorb more heat and
explain why they think so. After 10 minutes, have them feel both
surfaces. If possible, place a thermometer in the face of each
tin and measure the temperature difference.
Connections — Journaling and Discussion Questions
What differences did you notice?
could you explain them?
do your findings help you better understand the seasons?
Spark students’ thinking about why direct sunlight provides
more heat than angled (indirect) sunlight.
small groups two pieces of graph paper and a flashlight. Ask them
to lay one piece of paper on a surface horizontally to represent
the Earth, shine the flashlight directly on it from about two
feet away, and trace the outline of the light.
students to change the angle of the second piece graph paper (for
instance, by lifting it up a bit) to simulate the Earth’s
tilt in relation to the sun. They should place a notebook or other
hard surface behind it, again shine the light on it from the same
location, and trace the outline of the light.
and Discussion Questions
What do you notice about the amount of sunlight hitting each
piece of paper?
season do you suppose each piece represents and why?
do these findings, along with your investigations in part one,
help you better understand the seasons?
(When our hemisphere is tipped away from the sun during the winter,
the angled sunlight is spread over a greater area, so it not very
intense and doesn’t provide as much heat as when it hits
us more directly during the summer.)