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The effect of the medium on doppler shifts

  1. Jul 17, 2006 #1

    this has stumped me and i think there is something weird going on my definition of reference frames:

    lets look at two scenarios:

    scenario1:sound emitter and observer are both moving with velocity x in the same direction in a stationary medium... no doppler shift is expected.

    (stationary medium)
    <---emitter <---observer

    scenario2:the sound emitter and observer are both stationary and the medium is moving with velocity x. the observer percieves a doppler shift.

    >>---moving medium--->
    emitter observer

    it would seem if there exists a doppler shift in scenario 2 there would need to be a doppler shift in scenario 1 since the relative movement of frames SEEMS like the same thing but only a change in reference frames.

    so what is the true nature of scenario 1? i think i am not accounting for something since two scenarios that are seemingly alike produce different results.

    to me the answer should either be
    1) doppler shifts in both cases
    2) no doppler shifts in both cases
    3) i am not understanding the difference between a moving medium versus moving the emitter/observer which explains why there is no doppler shift in scenario 1 and a doppler shift in scenario 2.

    Last edited: Jul 17, 2006
  2. jcsd
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