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Index of Refraction definitions

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  • Index of Refraction
    A ratio of the speed of light in a vacuum to the speed of light in a material.
  • Speed of Light
    The constant speed at which light travels in a vacuum, approximately 3 x 10^8 m/s.
  • Vacuum
    A space devoid of matter where light travels at its maximum speed.
  • Material
    Any substance through which light travels slower than in a vacuum.
  • Water
    A material with an index of refraction of 1.33, where light travels at 2.25 x 10^8 m/s.
  • Air
    A common material with an index of refraction very close to 1, often approximated as 1.
  • Numerator
    The top part of a fraction, representing the speed of light in a vacuum in the index of refraction.
  • Denominator
    The bottom part of a fraction, representing the speed of light in a material in the index of refraction.
  • Constant
    A value that does not change, such as the speed of light in a vacuum.
  • Table
    A reference in textbooks listing indices of refraction for various materials.