Light is a form of energy that makes it possible for us to see the world around us. We need light to see. Do you know the main source of light on our planet Earth? Yes, it is a bright Sun that comes every morning to lit up the whole world around us.
Can you also create light? Yes, of course, you can! You can use man-made things to generate light like lamps, tube lights, torches and bulbs. You must have experienced a burning candle, a fireplace, or a match stick illuminating the dark room with its bright light.
Did you know there are animals that can make their own light? Fireflies, the firefly Squid and Crystal Jellyfish are some of them.
When you turn on a flashlight, it throws thousands of light beams around it. We say the flashlight is emitting light. Light sources are the things that emit light. Light sources can be natural or man-made. Natural light sources for example are the sun, fireflies, stars. Man-made light sources for example are torch, candle, bulb.
How light allows you to see things?
A teacup is kept on a table in a completely dark room. Without any light source, you can't see it. Now open the window and allow sunlight to pass through the room. You can easily see the cup, how?
When a light beam falls on an object, it bounces back. When this bounced back light beam reaches your eye you can see that object. This is called reflection of light. Reflected light allows us to see the world around us.
Have you seen a light beam passing through a narrow opening from a window into a completely dark room? You will observe the light beam entering the room in a straight line, the reason is light travels in a straight line!
Have you ever played with your shadow and wondered how are they formed? Your shadow is formed because the light can't pass through you or in other words you are blocking the light. Objects that are capable to form shadows are called opaque objects. Transparent objects allow the light to pass through, like glass, windowpane, clear plastic wrap. Transparent objects allow you to see clearly through them.
Do you know that a white light that you usually see around is made up of 7 colors? I can prove this to you with the help of a natural phenomenon that we all have witnessed, a rainbow! It consists of an arc that forms in the sky of seven colors, namely Violet, Indigo, Blue, Green, Yellow, Orange and Red, also called VIBGYOR for short.
A rainbow is formed when after heavy showers a bright sun appears in the sky. Rainbows are formed when light shines through the water. During the rains, millions of raindrops cause the colors in the white light to separate and bent through different angles. Each raindrop actually makes its own rainbow, but when there are so many raindrops at the same time, the rainbows become big enough for us to see with the naked eye. Rainbows appear in seven colors because water droplets break white sunlight into the seven colors of the spectrum (red, orange, yellow, green, blue, indigo, violet).
Let us perform a small experiment to create our own rainbow.
Things you need: Glass of water, a plane mirror, a torch, a blank paper
Perform this experiment in a completely dark room. Take a glass of water, place the mirror inside it. Take a torch and flash it towards the mirror. Watch a rainbow appear from the angle of your mirror. Now place the paper and see the seven colors!
