"Making Time"

 In "Making Time: A Study in the Epistemology of Measurement" by Eran Tal, it introduces the idea of a model based way to standardize the physical measurement of time as a quantity case. The time standardization success is what makes this case a good way to study the relationship between measurement and knowledge. As for the definition of a second, since 1967 it has been "defined as the duration of exactly 9,192,631,770 periods of the radiation corresponding to a hyperfine transition of caesium-133 in the ground state (BIPM [2006], p. 113)". This definition means that there is both a standard duration of a second and a also a specific frequency that defines a second. The second part is what these standard clocks are actually measuring. These standard clocks are measuring the frequencies of certain atomic transitions. This includes the caesium that is used to defined the second in of itself.