Refraction and Reflection Chapter 28 Refraction and Reflection
Reflection i r 1. Angle of incidence (i) = Angle of reflection (r) 2. Incident ray, normal, and reflected ray coplanar
Diffuse Reflection If successive elevations of a surface are no more than l/8 apart, then the surface is said to be polished at that wavelength. Most objects are seen by diffuse reflection.
Ray Diagramming Plane Mirror
Plane Mirrors Object Image
Plane Mirrors Image Properties: Virtual Erect Same Size
Reflection from Curved Surfaces (Concave shown here) Ray Diagramming f Principal axis Reflecting Surface The law of specular reflection is still obeyed.
Fermat’s Principle Light travels in straight lines and takes the path of least time. Predicts both reflection and refraction
Beach Water Whoa Baby Help Help Help
Refraction i air ni water nR R
Index of Refraction speed of light in vacuum n = speed of light through medium n = c / v ³ 1 ni sin qi = nR sin qR Snell’s Law
Because of atmospheric refraction, we have lingering, elliptical sunsets. Sun Earth Sun
Sunset
Mirage Cool air Warm air Surface of water?
Looming Warm air Cool air
960
Total Internal Reflection Critical Angle
Two Prisms in a Monocular
Dispersion in a Prism
Mercury Near Horizon
Rainbows
Green Flash Sun Earth Dispersion occurs causing multiple images of the sun. The last to set would be blue, but most of the blue has been scattered which leaves green.
Green Flash
Lenses Converging Lens
Lenses Diverging Lens
Ray Diagramming f Principal axis Applet1
Various Lenses Convex lenses are positive converging lenses. Double Convex Double Concave Plano Convex Plano Concave Convex Meniscus Concave Meniscus Convex lenses are positive converging lenses. Concave lenses are negative diverging lenses.
Lens Defects white Chromatic Aberration Spherical Aberration
Pinhole