Moving clock as seen by an observer at rest

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    Clock Observer Rest
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Discussion Overview

The discussion revolves around the perception of time as measured by a moving clock in a transparent rocket, as observed by a stationary observer on the ground. It explores concepts of time dilation, the relativistic Doppler effect, and the implications of relative motion on the observation of time intervals, including both theoretical and conceptual aspects.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants assert that a moving clock will appear to slow down due to time dilation when viewed by a stationary observer, but the perceived rate depends on the direction of motion relative to the observer.
  • Others argue that the apparent rate of the moving clock is influenced by the relativistic Doppler effect, where a clock moving towards the observer appears to tick faster, while one moving away appears to tick slower.
  • A participant emphasizes that time dilation is frame-dependent, stating that each observer perceives their own clock as ticking normally while observing the other's clock as running slow.
  • Some contributions suggest that the physical observation of the moving clock's rate can be affected by light travel time, leading to corrections in perceived time intervals.
  • There are discussions about whether the stationary observer would see the moving clock running fast or slow at different moments, depending on the clock's position and motion relative to the observer.
  • Participants mention the use of signals (like radio beeps) from the moving clock to illustrate how frequency shifts occur due to relative motion, complicating the perception of time intervals.
  • Some participants express uncertainty about the conditions under which the moving clock might seem to match the observer's clock rate, indicating a need for clarity on specific scenarios.

Areas of Agreement / Disagreement

There is no consensus among participants. While some agree on the principles of time dilation and the Doppler effect, others present competing interpretations of how these effects manifest in observations. The discussion remains unresolved regarding the specifics of how the moving clock is perceived under different conditions.

Contextual Notes

Participants highlight the importance of accounting for light travel time when interpreting observations, and there are unresolved questions about the implications of different frames of reference and the conditions under which observations are made.

  • #31
sweet springs said:
We should choose the frame where referred body is at rest and measure decay time in that frame. Thus observed value is "decay time".

More generally, it's called the proper time. It's the time that elapses between two events that occur at the same place. It's equal to the interval between the events, and is a relativistic invariant.
 
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  • #32
your simple act of distinguishing between "see" and "calculate" was immensely helpful and answered a question I had pondered for a long time. Thank you.
 
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