Interactions of Light Waves

1
Interactions of Light Waves

• EQ How are light waves affected by reflection,
  refraction and diffraction?

2
Reflection
EQ How are light waves affected by reflection,
refraction and diffraction?

• Reflect means bounces off of
• Regular reflection rays of light hit a smooth
  surface and the rays are reflected back at the
  same angle.
• Diffuse reflection rays of light hit a bumpy or
  uneven surface which causes the rays to bounce
  back at different angles

3
Absorption

• Transfer of energy carried by light waves to
  particles in matter
• Example flashlight beam shining through the air
  absorbs some of the light energy from the light.
  The result is a dim light. The farther the light
  travels from its source, the more it is absorbed
  by particles and the dimmer it becomes.

EQ How are light waves affected by reflection,
refraction and diffraction?
4
Scattering

• Interaction of light with matter that causes the
  light to change direction.
• Example Beam of light from a flashlight allows
  you to see things that are outside the beam.

EQ How are light waves affected by reflection,
refraction and diffraction?
5
Refraction

• Bending of a wave as it passes from one
  substance, or material to another. The change in
  speed causes them to bend, or change direction
• Refraction can cause you to see something that
  may not be there, like a rainbow or a mirage

EQ How are light waves affected by reflection,
refraction and diffraction?
6
Lens

• Lens a curved piece of glass or other
  transparent material used to refract light
  i.e. eyeglasses, binoculars, camera

EQ How are light waves affected by reflection,
refraction and diffraction?
7
Concave Lens

• thinner at the center than at the edges
• When rays of light pass through a concave lens
  the waves are refracted (bent) away from each
  other

EQ How are light waves affected by reflection,
refraction and diffraction?
8
Convex Lens

• Thicker in the center than at the edges
• When light travels through a convex lens the
  beams are refracted toward each other

EQ How are light waves affected by reflection,
refraction and diffraction?
9
Refraction and Color Separation

• When a beam of visible light enters the prism it
  is refracted. Each color bends in a different
  amount according to its wavelength.

EQ How are light waves affected by reflection,
refraction and diffraction?
10
Diffraction

• Bending of waves around barriers or through
  openings
• Light does not diffract a lot because the
  wavelength of light is about 100 times thinner
  than a human hair
• This means light cannot bend very much by
  diffraction unless it passes through a narrow
  opening, around sharp edges, or around a small
  barrier that is the same size or smaller than the
  wavelength of light

EQ How are light waves affected by reflection,
refraction and diffraction?
11
Interference

• Constructive interference two light waves
  combine to form a wave with greater amplitude
• Destructive Interference two light waves
  combine to form a wave with a smaller amplitude

EQ How are light waves affected by reflection,
refraction and diffraction?
12
Class Work and Homework
EQ How are light waves affected by reflection,
refraction and diffraction?

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• What did I learn
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• Read Interactions of Light Waves online
• Answer the chapter review questions