Light
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Light is a form of energy. It travels in straight lines.
Light waves travel in straight lines away from the light source until the waves hit something. This is why we can see straight "beams" of light coming from flashlights, car headlights, and the lamps of the lighthouse in the picture.
Unlike some other kinds of energy, light can travel through the vacuum of space. If it could not, the Earth would not receive light from the Sun.
Objects and materials interact with light. When light shines on an object, the object may absorb, reflect, or refract the light. The object's properties determine which of these events takes place.
When light strikes matter, three things can happen:
1. Light can be transmitted - Light passes through the substance it strikes.
Transparent - Light passes through so you can see clearly.
Translucent - Light passes through but is scattered so you cannot see clearly.
Opaque - Light does not pass through.
2. Light can be absorbed - Light passes into the substance and is held there.
3. Light can be reflected - Light strikes a substance and bounces back.
Light waves travel in straight lines away from the light source until the waves hit something. This is why we can see straight "beams" of light coming from flashlights, car headlights, and the lamps of the lighthouse in the picture.
Unlike some other kinds of energy, light can travel through the vacuum of space. If it could not, the Earth would not receive light from the Sun.
Objects and materials interact with light. When light shines on an object, the object may absorb, reflect, or refract the light. The object's properties determine which of these events takes place.
When light strikes matter, three things can happen:
1. Light can be transmitted - Light passes through the substance it strikes.
Transparent - Light passes through so you can see clearly.
Translucent - Light passes through but is scattered so you cannot see clearly.
Opaque - Light does not pass through.
2. Light can be absorbed - Light passes into the substance and is held there.
3. Light can be reflected - Light strikes a substance and bounces back.
The Behavior of Light
Reflection (smooth shiny surfaces)
Reflection occurs when light bounces off objects. How much reflection depends upon how even the surface is. If the surface is rough, the light scatters. If the surface is smooth and flat, the light will bounce off it at equal angles. That is why a flat mirror reflects a good likeness of the object being reflected.
Things that REFLECT light - mirrors, the surface of smooth water, and other SMOOTH SHINY surfaces.
Look at the diagrams below. Notice the angles at which the rays of light strike the surfaces.
Reflection occurs when light bounces off objects. How much reflection depends upon how even the surface is. If the surface is rough, the light scatters. If the surface is smooth and flat, the light will bounce off it at equal angles. That is why a flat mirror reflects a good likeness of the object being reflected.
Things that REFLECT light - mirrors, the surface of smooth water, and other SMOOTH SHINY surfaces.
Look at the diagrams below. Notice the angles at which the rays of light strike the surfaces.
Refraction
Refraction occurs because light bends. A lens is a piece of transparent material. It is usually made of glass and has at least one curved surface. Notice how the object appears distorted (bent or broken).
Things that REFRACT light - when you see something through water, lenses, or prisms.
Refraction is often referred to as the bending of light where two different materials touch. We most often see this property as light moves between air and water. The light is traveling at a certain speed, but when it makes contact with the water, the light waves are forced to slow down. This causes the object that the light is hitting, like a flower stem in water, to appear to be bent or broken.
Refraction occurs because light bends. A lens is a piece of transparent material. It is usually made of glass and has at least one curved surface. Notice how the object appears distorted (bent or broken).
Things that REFRACT light - when you see something through water, lenses, or prisms.
Refraction is often referred to as the bending of light where two different materials touch. We most often see this property as light moves between air and water. The light is traveling at a certain speed, but when it makes contact with the water, the light waves are forced to slow down. This causes the object that the light is hitting, like a flower stem in water, to appear to be bent or broken.
Prisms A prism is a tool that is used to bend light different amounts.
Prisms bend different types of light different amounts. Light coming from the Sun or from light bulbs carries many different colors of light. All of these colors together are known as the light spectrum. However, these colors can only be seen individually when they are separated from each other. Prisms separate the colors by bending them differently.
When sunlight enters a prism, the entire spectrum of light is spread out in a rainbow-like pattern because some colors are bent more than others.
White light is made up of many different colors of light, and a prism allows us to see this. Prisms are usually made of glass or crystal but can also be made of clear plastic.
Prisms bend different types of light different amounts. Light coming from the Sun or from light bulbs carries many different colors of light. All of these colors together are known as the light spectrum. However, these colors can only be seen individually when they are separated from each other. Prisms separate the colors by bending them differently.
When sunlight enters a prism, the entire spectrum of light is spread out in a rainbow-like pattern because some colors are bent more than others.
White light is made up of many different colors of light, and a prism allows us to see this. Prisms are usually made of glass or crystal but can also be made of clear plastic.
Absorption
Absorption occurs when the light is not reflected or transmitted. The color black is a great example of something that absorbs light. Black does not reflect any colors of light; it absorbs them all. The colors that our eyes are able to see result from objects' reflection and absorption of light.
The color that we see is the color that the object reflects; all of the other colors are absorbed by the object. For example, the yellow apple in the picture appears yellow because it is reflecting yellow light. The red apples appear red because they are reflecting red light. They are absorbing the other colors of light.
Material Properties
Different materials can have different interactions with light energy. Some materials reflect light. Some change the direction of light through refraction or diffusion. Other materials allow light to pass through. It is even possible for a material to do two or more of these things.
Materials have the quality of being opaque, translucent, or transparent, depending on how the materials interact with light.
Absorption occurs when the light is not reflected or transmitted. The color black is a great example of something that absorbs light. Black does not reflect any colors of light; it absorbs them all. The colors that our eyes are able to see result from objects' reflection and absorption of light.
The color that we see is the color that the object reflects; all of the other colors are absorbed by the object. For example, the yellow apple in the picture appears yellow because it is reflecting yellow light. The red apples appear red because they are reflecting red light. They are absorbing the other colors of light.
Material Properties
Different materials can have different interactions with light energy. Some materials reflect light. Some change the direction of light through refraction or diffusion. Other materials allow light to pass through. It is even possible for a material to do two or more of these things.
Materials have the quality of being opaque, translucent, or transparent, depending on how the materials interact with light.