How are Shadows Formed
What is a shadow?
A shadow is a dark region left behind an opaque object when some or all of the light coming from a source hits the object. The light cannot bend around the object, thus resulting in a shadow.
How to Form a Shadow
In order to form a shadow by yourself at home or elsewhere, you need a few easily available things:
A light source like a candle or torch
An opaque object like a block or book
A dark room
Creating a Shadow
Creating a shadow at home or in any room is very simple. With a little practice, you can create shadows of various shapes and sizes. You can even create moving shadows with the help of your hands or any object that depicts an irregular shape.
Shadows are formed when light in front of an object is blocked. A point source of light creates what is called an umbra, which is a completely black shadow with fine edges. A large source of light produces a central umbra and something called a penumbra, which is the region of semidarkness with blurred edges. This is where the darkness gives passage to light.
If you can produce white light by separate colored light sources, you would be able to see colored shadows instead of the typical black shadow. You can find below a few steps that detail ways of how to create different kinds of shadows:
Step One
Darken a small room with the help of curtains to ensure no outside light would interfere with what your experiment.
Step Two
Place a light source like a burning candle or a torch with bright light, on a table, focusing a plain wall. Make sure that there is a distance of 7 to 8 meters between the light source and the wall.
Step Three
Place a small opaque object between the light source and the wall. You should see the shadow of this object on the wall. If you would like to be more creative then you can try placing your hand between the light source and the wall and try moving your fingers, to come up with particular shapes. You can see the shadow of your moving hand and fingers on the wall.
Step Four
If you illuminate a room with a red light, you would be surprised to find shadows exclusively gray, or dark in color. If you illuminate the shadows with a white light, you would see the shadows colored in a distinctive green color. The place where both the shadows intersect, the shadows are gray in color. If you look at the region, which is away from the intersection, where the red light is blocked, the shadows are green in color. The area where the white light is blocked, the shadows are red.
Step Five
The more closely you move the object towards the light source, the bigger would be the shadow on the wall.