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Time dilation related questions

  1. Sep 24, 2008 #1
    hi all, I was just thinking about the following scenario :

    a spaceship traveling at near speed of light is orbiting around earth, now say the person onboard the spaceship is watching a tv news transmitted from earth to the spaceship at speed of light.

    say if the person on the spaceship watches the tv news for X amount of time related to him, does that mean the transmitter located on earth have broadcasted the tv news for >X amount of time related to the person on the spaceship? if so, then where has the lost time gone to?

    I mean, for example, if the person on spaceship watches current news, at the same time on earth are they already transmiting news from the future related to the person on spaceship's timeframe? but if the light speed is constant, shouldnt the person on the spaceship be watching tv news related to earth's timeframe?

    sorry I am getting kinda confused. XD, thanks for reading though.
  2. jcsd
  3. Sep 24, 2008 #2


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    Time passes at different rates for different people. There is no need for the duration experienced by the spaceship and the earth broadcaster to be the same. Suppose they communicate in some sort of morse code, with earth sending out pulses of blue light and red light. All that matters is that the number of pulses received by the spaceship is the same as the number of pulses broadcasted.

    Oh, and the spaceship will also only receive pulses after they have been broadcasted. It's exactly the same as "live broadcasts" on earth. When I watched the Beijing Olympics "live", I was of course not experiencing it simultaneously as the people in Beijing, I was experiencing it later because it took time for light (and the electrical signals) to travel from Beijing to Oregon.
    Last edited: Sep 24, 2008
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