Interactions of Light Waves EQ How are light

Interactions of Light Waves EQ: How are light waves affected by reflection, refraction and diffraction?

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 normal angle of incidence 60° angle of reflection 60°

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?

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?

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 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?

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?

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?

Convex Lens Thicker in the center than at the edges Convex Lens focal point When light travels through a convex lens the beams are refracted toward EQ: How are light waves each other affected by reflection, refraction and diffraction?

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?

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?

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?

Class Work and Homework Fill In • What did I learn • Confused • Say EQ: How are light waves affected by reflection, refraction and diffraction? Read “Interactions of Light Waves” online Answer the chapter review questions