Shadow Time

II. THE SCIENCE

This activity uses knowledge of the Earth's orientation to the Sun. For instance, it is important to know that the noon shadow in the northern hemisphere points north. A photograph with a shadow pointing directly toward the camera at a compass heading of 180 degrees (photographer facing south) implies that the photograph was taken about 12:00 PM.

The activity also uses a person's visual thinking ability. One has to orient the photographer relative to the scene in the picture; one has to visualize the shadow in the picture as a shadow on the Earth's surface; and finally, one must imagine how the Sun creates this shadow on Earth. Developing these spatial skills and knowledge of the Earth-Sun relationship are critical for understanding the nature of seasons.

Extending the Learning

A deeper understanding of the relationship of celestial objects in space can be developed by the exercise of visualizing the moon's orientation to both the Sun and Earth. Using printed copies of photographs of phases of the Moon (see below), place them in order from new moon to full moon to new moon. Using photographs of the moon with knowledge of its location in a particular area of the sky (e.g. rising, setting, at highest point), one can infer if the moon is waxing or waning.

Try working with shadows from different parts of the country. Be sure to sign up for a Light Buddy for this activity! Read on in III. Do It Yourself.

I. The Web Activity
II. The Science <—
III. Do It Yourself
IV. Do It with Your Students
V. Resources