السبت، 15 يناير 2011

the light



Light

Light, whether from the sun or some object, travels in a straight line. This can be easily seen by shining a flashlight in the dark. Light rays can bounce off materials, like walls, to provide light to other areas like around corners.
Light is a form of energy. If you hold your hand near a light you will feel it get hot. Some light sources can get so hot that they can burn you.
Some objects, like windows, are transparent allowing light to pass through them. Other objects are opaque, blocking the light from going through them.
Light

Shadows

If you hold your hand underneath a light, you will see a shadow of your hand. This is because your hand is opaque. It does not let the light shine through it. Therefore, the area behind your hand is dark, forming a shadow.Shadows

Reflection

Some surfaces, like a mirror, cause the light to bounce off. The light bounces off, or reflects back, at the same angle that it hit the surface. The amount of light reflected depends on the type of surface. Shiny surfaces reflect lots of light. Dull surfaces reflect very little light.
When you look in a mirror, you see yourself because the light shining on your body is reflected from the mirror back to your eyes.
Reflection

Refraction

When a light ray travels through a material the direction of the light will change. This is called refraction. The amount the light bends depends on the type of material.
A lense can cause light to change direction. If you have ever used a magnifying class to focus light to a small point, you are seeing refraction at work.
Refraction

Books on Light

  

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