An atomic clock and a normal clock

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Discussion Overview

The discussion centers around the behavior of atomic and mechanical clocks when subjected to relativistic speeds, specifically at 99% the speed of light. Participants explore how different types of clocks measure time and whether they are affected differently by relativistic effects.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants assert that both atomic and mechanical clocks slow down due to the first postulate of relativity.
  • There is a suggestion that the operation of different types of clocks could be affected differently depending on whether the spaceship is accelerating or if the observer is accelerating.
  • One participant proposes that the electrical circuits in a digital clock would run slower and that the batteries of a conventional clock would produce less power due to the speed of light limitation.
  • Another participant questions the assumption that the light from the two clocks would present different images to an observer, seeking clarification on the relationship between the clocks' behavior and the observer's perspective.
  • Some participants agree that all clocks, regardless of their construction, should exhibit similar relativistic effects, as they all rely on electromagnetic interactions at a fundamental level.
  • There is a discussion about the broader definition of clocks, including various physical systems that exhibit time-dependent behavior, as articulated by Einstein.

Areas of Agreement / Disagreement

Participants express differing views on whether mechanical and atomic clocks are affected in the same way under relativistic conditions. While some agree on the similarity of effects, others raise questions about potential differences in behavior based on the clocks' mechanisms.

Contextual Notes

Participants note that the discussion involves assumptions about the nature of time measurement and the effects of relativistic speeds on different types of clocks, which may not be fully resolved.

Galileo Galilei
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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Both clocks slow down. This is required by the first postulate of relativity.
 
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.
 
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?
 
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.
 
jtbell said:
in which case it is hard to imagine how the operation of different kinds of clocks (whether real or ideal) could be affected differently
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.
 
Galileo Galilei said:
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,
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?

Galileo Galilei said:
however from the perspective of a observer that experiences the ship travel by only the atomic almost stops yet the mechanical clock keeps ticking?
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?

Galileo Galilei said:
Basically are mechanical clocks effected with exactly the same conditions as atomic clocks or do the laws of physics differentiate between the two?
How is this question related to your scenario? I don't see the connection. Please explain.
 
Galileo Galilei said:
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?
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.
 
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).
 
  • #10
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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