the motion of the sun and time

The apparent motion of the sun and my disposition are interconnected. Here’s how to find out in a simple way from the Nature School.

aksiografi.com – The sun can be used as a pointer as we discussed in the previsious material. Now we will discuss the sun as a timpiece.

Learning Objerctive

We wil to study the relationship between the apparent motion of the Sun and time.

Materials

scissors

butcher paper

ruler

basketball

marking pen

transparent tape

 straw

modeling clay

flashlight

Procedure

1. Cut a strip of paper 4 inches (10 cm) wide and long enough to wrap around the basketball.

2. Fold the strip into three equal sections. Then fold it in half three times to make 24 equal sections.

3. Unfold the strip and draw a line on each fold.

4. Wrap the strip around the basketball and secure the ends together with a piece of tape.

5. Cut three 2-inch (5-cm) pieces from the straw. Use three dabs of clay to stand the straw pieces on three consecutive sections of the strip.

6. Turn on the flashlight and lay it on the edge of a table with the bulb facing outward.

7. Darken the room. Then stand with the flashlight to your right, holding the basketball so that it is about 6 inches (15 cm) away from the bulb and the first straw points straight toward you.

8. Observe the length of the shadows of the straws on the paper. Continue to observe the shadows as you slowly rotate the ball counterclockwise. Stop when the first straw points directly at the light.

Results

Shadows are cast by the straws. Straws closer to the light have shorter shadows.

Why?

As the straws get closer to the light, their shadows shorten until no shadow is cast by the straw pointing directly at the light. This is a simulation of Earth rotating on its axis toward the Sun, with each of the 24 sections on the paper representing one time zone. A time zone is any of 24 geographic areas into which the Earth is divided.

Clocks within a given time zone are set to the same time. The difference in the shadows indicates a difference in distance from the zone beneath the noonday Sun, when the Sun is at its greatest altitude (angular distance above the horizon), and thus a difference in time.