Definition of a clock in relativity theory

In summary, a clock in relativity theory is an object that measures the rate of time flow, but it is not explicitly defined in the theory. Instead, we rely on empirical definitions, such as the SI second, which is based on the duration of 9 192631 770 periods of the radiation corresponding to the transition between two atomic energy levels. This approach is preferred over defining a clock theoretically, as science is ultimately based on observation.
  • #1
kurious
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What is the definition of a clock in relativity theory?
 
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an object that measures the rate of time flow.
 
  • #3
Perfectly Innocent said:
Typically, the meaning of a clock is not defined in relativity. No reason to worry. Logically, it's OK to just have blind faith that "ideal clocks" really do exist conceptually.
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The quest for a good clock has developed slowly and empirically over time. A rather interesting show on the topic is "Longitude", in which the first naval chronometer was developed. The goal wa simple - to develop a clock that could be taken to sea, and still keep good enough time so that a person could determine their latitude by measuring the time at which the sun reached it's high point in the sky.

As a practical matter, we do have a definition for a "good clock" nowadays. But it's not a theoretical definition, it's one from a standards comission. I refer, of course to the SI second. And, to tie it in with my pervious comment, our "good clock" nowadays is also very small - it's an atom.

The second is the duration of 9 192631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. [13th CGPM (1967), Resolution 1]

It is a good thing, in my opinion, that we define our clocks empirically (through standards comittee's) rather than through theory. Defining a clock theoretically is not productive, as science has to be based ultimately on observation.
 
  • #4
kurious said:
What is the definition of a clock in relativity theory?

A friend of mine is a GR expert. He wrote an article on the nature of time and what is meant by a "clock". Its a great article and a good read. See

http://www.wfu.edu/~brehme/time.htm [Broken]

Pete
 
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What is the definition of a clock in relativity theory?

In relativity theory, a clock is any physical device that can measure time intervals. This can include traditional clocks like wristwatches or digital clocks, as well as more complex devices like atomic clocks.

Why is the definition of a clock important in relativity theory?

The definition of a clock is important in relativity theory because it allows us to measure time intervals, which is a crucial concept in understanding the effects of time dilation and the relativity of simultaneity.

How does relativity theory define the measurement of time intervals using a clock?

Relativity theory defines the measurement of time intervals as the comparison of two events using a clock. The clock measures the time elapsed between the two events, and this measurement can vary depending on the relative motion of the clock and the events.

Can any clock be used to measure time intervals in relativity theory?

No, not all clocks can be used to measure time intervals accurately in relativity theory. The clock must have a well-defined and consistent way of measuring time, and it must also be able to withstand the effects of motion and gravity.

How does the definition of a clock in relativity theory differ from the traditional definition of a clock?

The traditional definition of a clock is based on the regular motion of a pendulum or the oscillation of a quartz crystal. However, in relativity theory, the definition of a clock is more general and includes any physical device that can measure time intervals, regardless of its mechanism.

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