The Sun & Time
The sun is one of the most important things to our planet, and it isn't even on earth! We find our sun at the center of our solar system. We can see the sun in the sky, but it is really very far away, in fact, it's bigger than earth is! The sun is made up of an element called hydrogen. It produces light and heat by changing the hydrogen into helium. Earth depends on the sun for light and heat energy, which we use to power our world!
With the help of the sun, we can have fun with science. The sun's light is what plants use to grow and make food. The sun is also what some scientists use to make electricity so we can have lights at night, and cooked food, and television too! See how important the sun is?
We've already learned that the hours that the sun rises over the eastern horizon, makes its way across the sky and begins to set on the western horizon are called day or daytime hours. When the sun is not in the sky, it is nighttime. At nighttime, the moon can rise and provide light.
Did you know that the moon gets its light from the sun? Studying this is one of the ways we can have fun with science. Just like a glow in the dark ball needs to be put up against the light before having light of its own, the moon needs to see the sun in order to bounce back its light unto earth. The nights that we don't see the moon are nights when the moon is not seen by the sun.
Apart from daytime and nighttime we have also already learned about shadows. Shadows are what happens when light is being blocked by an object. When the sun rises, its light cannot reach every single place, and the places where it doesn't reach usually have shadows. This means something is standing in the sun's way. Houses can have shadows, so can trees, rocks, mountains, and humans!
When the sun first rises, you will see that your shadow is long. As it makes its way around the sky, shadows get shorter and shorter, until finally, your shadow is right under you, like you're stepping on it! This happens at noon time, when the sun is at its highest point, or at a 90 degree angle to the horizon line. As the day progresses and afternoon arrives, shadows will become long again. Have fun with science and test this out. Go outside every few hours and observe your shadow. What do you notice?
You will notice that your shadow is getting shorter or longer depending on the time of day. Since shadows get long and short, and make their way around you as the sun rises and falls, we can say that we will be able to tell what time it is depending on the position and length of our shadow!
In the projects section of second grade science, you will learn how to have fun with science and make a sun dial! This sun dial is like an outdoor clock. It tells the time depending on the position of the sun, and by the shadow that the dial (a stick or triangular object) will make.