prisms, total internal reflection, polarization, how we see color, how vision is corrected and...
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Prisms, total internal reflection, polarization, how we see color, how vision is corrected and rainbows.
Prisms
High frequency light in a transparent medium travels slower than low frequency light (red light travels faster than violet light)
Thus, the different colors are refracted at different angles.
When white light is refracted twice, and the second surface is not parallel to the first, the dispersion is noticeable, thus the colors are observed.
If the two boundaries of the medium are parallel, the refractive effects at the first boundary are reversed at the second boundary.
Total Internal Reflection
Light can be reflected off a transparent medium boundary at a certain angle.
This angle is called the critical angle.
Fiber Optics
Optical FibersOptical fibers, sometimes called light pipes, are transparent fibers that pipe light from one place to another. They do this by a series of total internal reflections. Optical fibers are useful for getting light to inaccessible places. Mechanics and machinists use them to look at the interiors of engines, and physicians use them to look inside a patient’s body.
29.12 Total Internal Reflection
Total Internal Reflection
Total Internal Reflection
http://www.phy.ntnu.edu.tw/java/optics/path_e.html
http://micro.magnet.fsu.edu/primer/java/refraction/criticalangle/index.html
Polarization of Light
Light consists of waves vibrating in all planes (360o).
A polarizer allows only the light wave along one plane to pass through.
Two polarizers if oriented at right angles will cancel all light.
Glare (reflected light polarized in a plane parallel to a non-metallic surface) is greatly reduced when using polarized lenses.
http://lectureonline.cl.msu.edu/~mmp/kap24/polarizers/Polarizer.htm
When sunlight passes through a prism, it separates into a spectrum of all the colors of the rainbow.
28.1 The Color Spectrum
roygbiv
dispersion
The phenomenon of incoming light of different wavelengths being bent at different angles when passing through a medium.
Red light is bent the least; violet the most Prismatic effect (Dark Side of the Moon)
produces rainbow colors: White light is separated into roygbv.
Isaac Newton—discovered that white light is composed of seven (or six) different colors of light
White Light
Red
Orange
Yellow
Green
Blue
Violet
A prism disperses white light into its primary frequencies of color
Dispersion of white light into component colors
http://hyperphysics.phy-astr.gsu.edu/hbase/ems3.html
R Nave
Prisms
http://www.physics.mun.ca/~jjerrett/dispersion/prism.html
http://micro.magnet.fsu.edu/primer/java/prism/index.html
Rainbows, etc.
http://mysite.verizon.net/vzeoacw1/rainbow.html
http://micro.magnet.fsu.edu/primer/java/refraction/refractionangles/index.html
Refraction
http://freespace.virgin.net/gareth.james/virtual/Optics/Refraction/refraction.html
http://www.physicsclassroom.com/Class/refrn/u14l1f.html
http://acept.la.asu.edu/PiN/mod/light/opticsnature/pattLight4Obj1.html
http://www.wrh.noaa.gov/Flagstaff/science/skyblue.htm
http://www.cordonline.net/laserapplets/
polarization
Light that is reflected or transmitted through specific materials such that all vibrations are oriented on single plane.
A polarizer allows only one plane of light through.
polarization
1st polarizer eliminates all but one plane
2nd polarizer when oriented at a right angle to this plane eliminates the remaining plane
polarization
Sunlight is horizontally polarized when reflecting off a surface, producing glare (off a pond, river, car, road, etc.)
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