2 Review: Light – EM waves produced by the vibration of particles Visible light – part of the EM spectrum that we see and that interacts with materials around usTransmission: any transfer of energy through matter or spaceLight will transfer through a medium or empty space
3 Materials Transparent Translucent Opaque Light passes through the object completelyExamples: plastic wrap, windowsTranslucentLight passes through the object somewhatExamples: frosted glass, wax paperOpaqueLight does not pass through the objectExamples: books, aluminum foil
4 Reflection and Refraction Processes where light is manipulated, changed
5 Reflection Light hits and object and bounces back to the viewer The light bounces back at the same angle it hit the objectExamples: mirrors, some windowsSmooth surfaces create regular reflections which means that the light reflects in one directionRough surfaces create diffuse reflections which mean that the light reflects in different direction.Diagram:
7 Refraction Diagram Light hits an object and travels through it BUT It will travel through the object at a different angle than how it hitCreates an optical illusion. Objects may be closer or further away from where you think they are. Ex. A fish in the water.When white light is refracted, you can see the entire visible spectrum.Examples: light traveling from air to water, prismDiagram
8 Absorption Light is taken in by an object Example: when a beam of light shines through the air, particles in the air absorb some of the energy from the light. AS a result, the beam of light becomes dim.
9 ScatteringLight is broken up and travels through a medium in smaller particlesExample:Beam of light scatters because of air particles, allowing you to see things that are outside of the beam.
10 Diffraction Bending of waves around barriers or through openings Depends on it wavelength and the size of the barrier/openingWavelength of visible light is very small – so it cannot bend very much unless it passes through a narrow opening, sharp edgeLight waves cannot diffract around large obstacles (buildings). Thus, you can’t see around corners