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Section 2.2: Exploring Synchronizing Clocks by Viewing



viewer x = m | viewer z = m

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What we, as omnipresent observers, are recording in our laboratory notebooks after the synchronization of clocks is not what a viewer who sees the lattice of clocks from a fixed point in space would see. A viewer would not see all of the clocks synchronized because of the light-travel-time delay. Instead he/she would see what depicted by a viewer.  Note that when we talk about reference frames and synchronized clocks, we do so in the sense of what an intelligent observer or an omnipresent observer would observe (the light-travel-time delay is removed).  Often students (and physicists alike) mistakenly believe that all of the strange things that are a part of special relativity are due to light-travel-time delay; they are not.

Vary the x and z positions of the viewer to see the effect of light travel time on the clock readings as seen by the viewer (position is given in meters and time is given in the time it takes light to travel one meter or 3.33 × 10−9 seconds).

  1. How do the clock readings change as you vary the x position of the viewer?
  2. How do the clock readings change as you vary the z position of the viewer?
  3. Where does a viewer need to be located in order for the clocks to appear (approximately) synchronized?
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