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Light Passing through a Moving Medium

  1. Jan 16, 2010 #1
    I was looking at light sources Bending in Accelerating objects from this astronomy page
    http://www.astronomynotes.com/relativity/s3.htm" [Broken]

    Then i began to wonder if this moving elevator was made of glass then the light would
    hit the glass and "move slower". Then if the glass was moving i was thinking the light would be shifted, but that thought to me seems to have some flaws.

    I was also wondering about the index of refraction. From the perspective of the person in the elevator the light is hitting the glass at an angle which would cause it to bend more.
    i was thinking that a moving light source would have an electromagnetic wave similar to the graph y=Sin(x)+x, and a stationary light source tilted on an angle would be the y= sin(x).
    So i relize there is probably a difference between moving light, and light tilted on an angle, but
    i would like to know if there is any difference in the index of refraction.

    Any knowledge on these concepts would be appreciated.
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jan 16, 2010 #2


    Staff: Mentor

    This is correct. It is called Fresnel drag and was first measured in 1851 by Fizeau (http://en.wikipedia.org/wiki/Fizeau_experiment). This result is consistent with special relativity which was developed more than 50 years later.
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