This is a guest post written by Mary Kate Warner.

Illustrating Light and Dark – A Spring Science Experiment

The first day of spring, or the Vernal Equinox, falls on March 20th. Everyone knows they can look at their calendars and find the first day of Spring, but some kids may not know this day is known as the vernal equinox. This easy experiment will demonstrate what natural phenomena happen on that day.


• Craft foam ball• Pencil• Lamp• Bamboo skewer• Graph paper• Clipboard• Masking tape• Flashlight• Paper to record log• Black marker

Introduction to the Spring Science Experiment:

Early mankind celebrated the Vernal Equinox for the basic reason that their food supplies would soon be restored. But the date is significant in Christianity because Easter always falls on the first Sunday after the first full moon after the Vernal Equinox. The Vernal Equinox is another example of the perfection of His creation of the world.


1. Make two dots on the globe with black marker, one at the top and one opposite on the bottom.

2. Draw a circle around the middle of the ball. The circle represents the equator which divides earth into the Northern Hemisphere and the Southern Hemisphere.

3. Insert a bamboo skewer through the center of the ball to represent the north and south poles.

4. Place the ball on the pencil at a tilt to represent the planet titled on its axis.

5. Hold the Earth model with the axis perpendicular to the floor in front of a lamp to represent the Sun. Move it around the lamp as if in orbit. Note that the light strikes Earth’s different hemispheres equally.

6.Note that the Northern and Southern hemispheres have an equal amount of lighted and darkened regions. This is because the poles of Earth are parallel to the sun. This is the Vernal equinox.

7. Attach a sheet of graph paper to a clipboard with masking tape. Hold the board perpendicular to the floor and shine the flashlight directly onto the graph paper about two feet away. (Be sure the flashlight is parallel to the floor, and, therefore, perpendicular to the paper. )

8. Trace the outline of the flashlight’s beam on the graph paper. Keeping the same distance from the paper to the flashlight, rock the board towards and then away from the flashlight.

9. Tilt the clipboard at a large angle like 45° or 60° and trace the new outline of the beam with a different color.

10. Note that more area is covered by the beam when the board is tilted at larger angles. When the same amount of light is spread over a larger area, the intensity of the light decreases.

Explanation of the Spring Science Experiment:

Equinoxes occur when the axis of rotation of the earth (i.e. the line form the N to S poles) is exactly parallel to the direction of motion of the earth around the sun. This happens on just two days of the year, which are the spring and autumn equinoxes. This means that day length is exactly the same (12 hours) at all points on the earth’s surface on these days.


We all feel the joy of going from the darkness of winter into the light that comes with spring. And going from the darkness of sin into the light of God’s forgiveness is also a blessing. All who do evil hate the light and keep away from it for fear his evil deeds might be exposed. Isa 29:15-16: “Woe to those who go to great depths to hide their plans from the Lord, who do their work in darkness and think, “Who will see us? Who will know?” But our Lord will know. The Bible tells us that Jesus came to us as a light so that no one who believes in Him should stay in darkness.

If you tried this activity with your kids, please let us know what you think!

Check out some other craft projects by Mary Kate: How Lungs Work | Glass Half Full Science Experiment

The above post was written by guest blogger, Mary Kate Warner. For questions about this activity, please reach out to her personally at Christianity Cove.