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In support of all the students who are displaced from school due to the Corona virus. Access to physics zone and chemistry zone lessons are now available free of charge. This will be maintained at least through August 1st 2020. Learn and be well.

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Applications of Total Internal Reflection

Total Internal Reflection can be used as a way to make diamonds sparkle and information travel rapidly on light waves through a fiber optic.

diamond animation The cut of the diamond favors total internal reflection.  Most rays entering the top of the diamond will internally reflect until they reach the top face of the diamond where they exit.  This gives diamonds their bright sparkle.   Notice in this animation that a ray entering the top doesn't exit the diamond until it reaches the top surface.
Fiber Optic Animation

A fiber optic is a glass "hair" which is so thin that once light enters one end, it can never strike the inside walls at less than the critical angle.   The light undergoes total internal reflection each time it strikes the wall.   Only when it reaches the other end is it allowed to exit the fiber.
 
Fiber optic cables are used to carry telephone and computer communications.  Advantages over electrical wired include:

  1. Fiber optics can carry much more information in a much smaller cable.
  2. No interference from electromagnet fields result in "clearer" connections.
  3. No electrical resistance.
  4. No hazard of electrocution if cable breaks.