Clarification on Fundamental and Derivative Physical Measurements: What about Clocks?

I made, in the last post, what was probably a rash and incorrect speculation: I said that the straight edge and protractor are the fundamental physical measuring devices and that all others are derivative from these. Well clearly we need to add clocks to the list. Or do we?

Well a straight edge and a protractor are easily constructed and they are literally all the same (or perhaps I should say that they are all geometrically similar). But clocks are a great deal more complex.

Clocks all seek incremental measurements of time in an analogous manner to the way straight edges seek to measure length and protractors seek to measure angles. But unlike the cases of length and angle, the measurement of time increments is a much more derivative and tricky affair. We have direct measurement access to lengths and angles but we do not have direct access to time. Only through the observation of some natural or engineered process are we able to infer increments of time. By its very nature a process involves the movement or change of some observable object over time.

However a merely observable process will not suffice to serve as a clock. For a process to be utilized as a clock an object must go through repetitive or cyclical change. The beatings of our heart, the movement of a shadow in the sun, or the vibrations of a spring are the traditional components of both natural and engineered clocks.

Does the use of a clock require the use of a meter stick or protractor? Obviously not. To use a clock to determine an increment of time entails simply being able to observe an end point to a process. For example if we have an hour glass all we have to observe is that all the sand at the top of the glass has flowed into the bottom part in order to infer that an hour of time has elapsed. To see that five minutes have elapsed on a traditional non digital watch we need only observe the beginning and end of the movement of the minute hand through the arc length between any standard demarcated five minute interval.

So a clock is a fundamental measuring device as opposed to a derivative one.