Grades K–2 · Earth & Space
How does a shadow change during a day?
A stick can stay still while its shadow moves across the ground. The stick blocks sunlight, making a darker patch away from the Sun; changing the light's direction changes where that patch falls.
Earth turns during the day, carrying the ground and stick with it. From the ground, the Sun appears to change place in the sky. Its light reaches the same stick from different directions, so the shadow changes even though the stick has not been moved.
In the Morning picture, the low Sun is left of the stick and the long shadow lies to its right. The light line connects the Sun's direction to the shadow's position.
In the diagramMorningShadow points right
Low sunlight from the side makes a long shadow, while a higher Sun can make a shorter one. Later in this pictured day, light arrives from the other side and the shadow points the other way. The pattern depends on place and season.
About this explanation
Starting knowledge: Recognize the same object in several pictures and compare long and short.
Sources
- NASA — Changing Shadows