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What are the Properties of Light? And What is White Light?. Unit 4 Lessons 1 and 2 4-5.2, 4-5.3. Different kinds of Light. Light is a form of energy. A light bulb, a burning log, and a hot stove burner are a few common sources of light.
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What are the Properties of Light? And What is White Light? Unit 4 Lessons 1 and 2 4-5.2, 4-5.3
Different kinds of Light • Light is a form of energy. • A light bulb, a burning log, and a hot stove burner are a few common sources of light. • Some living things are sources of light too. Fireflies and some fish that live deep in the ocean are two kinds of animals that give off light.
Different Kinds of Light • The most important light source is the __________________. • Without a constant supply of the Sun’s light, Earth would be too cold and dark for any kind of life. • The Sun’s light comes to Earth in the form of waves. We can’t see all of the Sun’s light waves. The part we can see is visible light. • Invisible light- the part we can’t see- is made up of X Rays, microwaves, radio waves, and other kinds of light.
Two Properties • Visible light can be described by its properties. • One property of light is color. • The sun’s light may look white, but it is made of many different colors. You can see these colors when you look at a rainbow. • All the colors in the rainbow make white light when they are combined. • Not all light bulbs give off the same amount of light. • For example, some bulbs may give off light that is slightly pink and others may give off yellowish light. • Other lights we call neon lights give off very bright colors of light. • The colorful light is produced when the gas in the neon light bulbs is heated to very high temperatures.
TWO Properties • Another property of visible light is brightness. • Brightness may be described with words such as dim, bright, and brilliant. • Compare the light from a spotlight to the light of a candle. • How bright the light from a source appears depends on the amount of light the source gives off and how close it is to you. • The light from the spotlight might appear much brighter if both sources are the same distance from you. But if you move the spotlight far away, the candle will appear brighter.
Colors of Light • White light from the Sun is actually made of many colors. You see these colors in a rainbow. • The colors of light in a rainbow always appear in the same order- red, orange, yellow, green, blue, indigo, and violet. (ROY G. BIV) • What causes light to separate in this way? • Light that we see travels in waves. • These waves do not all have the same properties. • One way the waves differ is in wavelength. • Wavelength is the distance between one point on a wave to the next similar point on a wave.
Colors of Light • You see a rainbow because as sunlight passes through raindrops, it is separated into different colors according to wavelength. • Red light has the longest wavelength. It also has the lowest energy. • Violet has the shortest wavelength and the highest energy. • All the remaining colors in white light are arranged between two colors.
Separating light • You don’t have to wait for a rainbow to separate light into its different colors. • A prism is an object that bends light as the light passes through it. • The amount of light that a prism bends depends on the light’s wavelength. • When white light leaves a prism, it is separated into the different colors you see in a rainbow. • The colors are arranged from the longest wavelength to the shortest wavelength. • No all light sources give off all colors of light. For example, a source may give off only red light. If you pass that light through a prism, you would see only colors of red.
