Shadow Science 

5-ESS1-2. Represent data in graphical displays to reveal patterns of daily changes in length and direction of shadows, day and night, and the seasonal appearance of some stars in the night sky.

At some point of time long ago children might have used their hands to make shadows of different animals like dogs, deer and peacocks on the wall in the light of a candle or torch. It is still one of the most favourite pastimes of the children who live in areas that experience frequent power cuts. Take a look around you, and you will find a number of things that have shadows. You will see that furniture, decoration pieces, trees, electrical appliances and many more things in your house have shadows. Let’s explore  how shadows are formed.

How are Shadows formed?

Shadows are formed when an opaque object is placed in the path of light rays. An object through which no light can pass is known as opaque. One such example is your body. Since light cannot pass through your body, it forms a dark region. This dark region where the light cannot reach is known as a shadow. Opaque objects form clear dark shadows. A transparent object does not make any shadow as light passes straight through it. Translucent objects create faint shadows as light is able to pass only partially through them.

While the presence or absence of light is responsible for forming shadows, there are other factors related to it that determine the shape and size of the shadows. If the angle of the light is smaller, then the shadow formed will be much longer than usual. If the object is very close to the light source, larger shadows are formed and if an object is moved away from the light source, the shadow becomes smaller in size. The size of the shadows is also determined by whether the object is in motion or not. The size of the shadow is always slightly longer and larger than the moving object.

The size of the light source also plays an important role in the formation of shadows. Bigger light sources form blurry shadows. If the light source originates from various directions and points, several shadows will be formed and some of them may even overlap. Depending on the color of the light, you will also see shadows of different shades. Colored shadows are formed when the multi-colored light sources produce white light.

Your turn

1. Shadow puppetry is the art of using the shadows of puppets to entertain the audience. Research this art form at https://wonderopolis.org/wonder/what-are-shadow-puppets and make a infographic about its history.   Send this to the EY coordinator in your building.
   

2. Your shadow is longest in the early morning and in the late afternoon. In the afternoon, when the sun is directly above you, your shadow leaves your side for a little while. The sun makes the longest shadows at the beginning and at the end of the day because at that time, the sun is lowest in the sky and aimed at the sides of the various things on the earth. When the sun is directly above you, there is little or no shadow because the light from the sun is falling upon you from all the sides and there is hardly any dark region. Make a teaching page for a younger child to understand this process.   Send this to the EY coordinator in your building.
   

3. A long time ago, people observed the way shadows were formed by the sun and utilized this principle in making the world’s most primitive clocks, the sundials. Learn about sundials by watching this video. Make your own sundial and take pictures of it doing its job. Send a picture to the EY coordinator in your building.