لخّصلي

How do we see things around us? You will probably say it's the eyes that help us to see the objects around us. But will our eyes be able to see these objects in dark? No. We need light to see things. Without light, we cannot see the objects. But where is this light coming from? This light is coming from this source, which is a fluorescent bulb. You see that? This bulb is emitting its own light. The objects which emit their own light are called luminous objects. Can you give me any other examples? Incandescent light bulb. The sun, the stars are also luminous objects. What about objects such as this table and chair? Do they emit their own light? No, these objects do not emit their own light. Such objects are called non luminous. Almost everything around us is non luminous. Objects made up of wood, plastic, cotton, metal are all non luminous. What about the moon and the planets? They are also non luminous. But if the moon is non luminous, then how come we're able to see it at night? The answer to this is reflection of light. The reason we are able to see any non luminous objects around us is because of the reflection of light. Reflection of light can simply be referred to as change in direction of light or bouncing of light from some surface. Just like the ball bounces from the ground, light reflects off from a smooth surface. Let me try to explain this in a simple way. The light from the source strikes the object and bounces off from its surface. And when this light reaches our eyes, we see that object. And this is how we see nonluminous objects. When the object is kept in front of the mirror, its image is formed in it. But will we be able to see the image in the dark? No, we won't. So the formation of the image is also due to reflection of light. Let this object be our human body. So at the same time, we are looking at the image. First, tell me, is our body a luminous or a non luminous object? Well, it's non luminous. Human body cannot emit its own light. So the light from the source is first incident on the human body. It gets reflected from it, and this reflected light strikes the mirror. This light is further reflected from the surface of the mirror and reaches our eyes. This is how we are able to see our image. Now, obviously, this is not the exact picture of the happenings. I just wanted to give you the intuitive feeling into how this happens. There are a lot of subtleties involved, which we will learn in our higher grades. Our.