The Nature of Light

Light is energy that you can see, and it travels through space in the form of waves. A wave is an oscillating repetitive motion that travels through matter or space. There are several other forms of energy that also travel as waves. For example: radio, and X ray waves. These are examples of radiant energy. Light is the only form of radiant energy that is visible to the naked eye.

Nearly all of the earth's light comes from the sun. The sun is a whirling cloud of very hot gases. These gases glow very brightly,and have been giving out visible light for millions of years. The sun is 148.8 million kilometers away from earth (93 million miles), but its energy travels so fast that it reaches us in only 8 minutes. Light waves travel much faster than other kinds of waves, such as sound waves. The speed of light is about 300,000 kilometers per second which means that every second a light wave travels about 300,000 kilometers.