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Constant velocity vs accelerating source

  1. May 27, 2009 #1
    Would a signal sent from a transmitter, traveling at constant velocity toward an observer, arrive at the same time if it were accelerating toward that observer? The signals are sent at the same relative distance from the observer. Would the result be the same if the transmitters were receding from the observer?
  2. jcsd
  3. May 28, 2009 #2
    Same proper distance from the recipient, yes. Which means at the same distance distance according to the recipient.

    If you doing all the relative distances according to the transmitter, then no.


  4. May 30, 2009 #3
    brightonb, i don't think there would be a difference because the speed at which light travels (c) is constant and does not depend on the motion of the observer as long as the light is emitted at the same distance from the transmitter in both cases.
  5. May 30, 2009 #4
    You have constrained you inquiry by the phrase "traveling at constant velocity" so of course any two signals traveling at the same constant velocity would arrive at the same time from the same distance.

    I think your real question is
    and the answer is "yes" because the speed of electromagnetic radiation (say, light) is independent of the speed of the source or the observer.
  6. Jun 8, 2009 #5
    Only one source is moving at constant velocity, the other is accelerating but they both transmit a signal from the same location. e.g., the c.v. source could be moving at 100 mph while the accel source could be at 1000 mph at the transmission time.
  7. Jun 9, 2009 #6


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    Both signals will have the same velocity. The state of motion (velocity, acceleration, etc) of the emitter is irrelevant.
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