Any number, N, such as the numerical value of a physical constant measured in any units, will be mapped by any function, f, of the observer’s choice to a rational number, n, that will lie within any infinitely-divisible discrete framework of the observer’s choice. Although all numbers N map to numbers n that lie within the framework, interesting N map to n that are integers, or fractions of low denomination. The value of n explains the value of N in terms of the function f. For this observer, numbers N that characterise particularly interesting quantities often are found to map to numbers n that are precisely multiples of 25. Many examples are shown, where N is the numerical value of a quantity measured in Planck, SI or diverse other units. Physical constants whose values have been produced by means of conceptual observation conform to all of reality as known by the observer — hence the apparent fine-tuning of the universe for life. Because physical constants hold good for all time, past and future, it seems that time is an intuition of the observer, as argued by Kant. Conceptual observation has been used to correlate physical parameters, with implications for the origin of physical laws.