75 All About Light-High

All About Light Written by Brian Roberts

Introduction Have you ever walked into a room at night and turned off all the lights? Everything is dark. Without light, it is hard to see anything. If you turn on the lights, you can see clearly.

What Is Light? Light is a kind of energy. You can't touch light, but you can see the things it lights up. Your eyes see light and send signals to your brain. Your brain interprets, or tells you what you are seeing. This is how your sense of sight works.

Sources of Light Some objects can make light. The Sun and a fire make light. A flashlight and a TV screen also make light. Each one is a source of light. Most objects do not make their own light. Clouds and pencils do not make light. You only see them when rays from a light source shine on them. Wowser! A firefly is a light source! Inside its body, the firefly mixes chemicals to give off flashes of light.

When Light Shines on Objects Several things can happen when light shines on an object: Almost all the light passes through the object. A little bit soaks into the object and a little bit bounces off. Some light passes through the object. Some of it soaks into the object and some bounces off. No light passes through the object. All of it soaks in or bounces off.

Light can pass through the air, most glass, and clean water. Only some light passes through wax paper, clouds, and dirty water. No light passes through books and walls. When objects block some or all of the light, they absorb it, or soak it up. Other objects reflect the light. This means light bounces off them. Most objects absorb some light and reflect the rest. Do You Know? The Moon does not make light. Instead, it reflects sunlight that shines on it. Some of that light is reflected toward Earth, which is why you can see the Moon.