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An atomic clock and a normal clock

  1. Nov 19, 2014 #1
    Two clocks in a spaceship floating though space at 99% the speed of light. One is a atomic clock and uses light and mirrors to measure time, the other clock uses cogs and gears like a conventional clock. From the perspective from inside the ship both clocks tick and tock at the usual rate, however from the perspective of a observer that experiences the ship travel by only the atomic almost stops yet the mechanical clock keeps ticking? Basically are mechanical clocks effected with exactly the same conditions as atomic clocks or do the laws of physics differentiate between the two?
     
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  3. Nov 19, 2014 #2

    Dale

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    Both clocks slow down. This is required by the first postulate of relativity.
     
  4. Nov 19, 2014 #3

    jtbell

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    Note that you can make the spaceship and clocks travel at 99% of the speed of light either by accelerating the spaceship (firing its engines), in which case the acceleration can have different effects on different kinds of real clocks; or by accelerating yourself while the spaceship simply keeps on "doing its own thing," in which case it is hard to imagine how the operation of different kinds of clocks (whether real or ideal) could be affected differently.
     
  5. Nov 19, 2014 #4
    I can see why they would behave the same, the atomic clock is slowed down because its limeted by the universal constant of light but in the case of a macanical clock i think that the rate in the electric in the clock travels will also be inhibated slightly which would cause the macanical clock to slow down preportionatly to the atomic clock, would you agree?
     
  6. Nov 19, 2014 #5
    Basically the curcuits of a digital clock would run slower and the batterys of a conventional clock would chuck out less power, this would depend on electric being restricted to the speed of light also.
     
  7. Nov 19, 2014 #6

    A.T.

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    It would lead to paradoxes, if the rate ratio of two clocks placed next to each-other at relative rest would depend on the observer.
     
  8. Nov 19, 2014 #7

    ghwellsjr

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    I presume that when you say "from the perspective" you mean that both clocks have some kind of display on them that an observer inside the ship can watch and see that they are ticking at the same rate. In other words, if he sees at one moment in time that they are displaying the same time, then any time later he can see that they continue to display the same time. This means, of course, that the light coming from both displays takes the same amount of time to reach his eyes, correct?

    I presume again that when you say "from the perspective", you mean that this second observer sees the two clocks traveling at some high speed away from him. But why do you think the light coming from their two displays would present different images to his eyes?

    How is this question related to your scenario? I don't see the connection. Please explain.
     
  9. Nov 19, 2014 #8

    Dale

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    If I understand correctly your point then yes I agree. Also, all wind up or other similar clocks also use EM interactions at a basic level.
     
  10. Nov 20, 2014 #9

    jambaugh

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    As mentioned even if you build the clock from wooden cogs and bailing wire, the base interactions between the parts are still electromagnetic. But the equivalence is still at a deeper level. You could imagine building a clock using say the gluon interactions of the strong force but you still should see the same relativistic effects on all types (given the assumptions of the theory of relativity).
     
  11. Nov 20, 2014 #10

    Nugatory

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    Einstein said it best when he said "time is what a clock measures". In this context, a "clock" is any physical system that displays any sort of time-dependent behavior, regardless of its construction and regardless of whether it was designed to measure the passage of time. An atomic clock qualifies, as does a mechanical clock or even a sandglass - but so do biological processes such as the greying of hair (most useful for multi-year time scales, and still not very precise), the decay of meat and radioactive material, ....

    It's worth googling around for some of the commentary and elaboration that Einstein's wonderfully succinct statement has generated.
     
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