Well I have no access to S&Z 3rd edition, but I believe you. Declaring something as indefinable and then defining it is oxymoronic. Science is already loaded with plenty of oxymorons and science does not really need any more.
This discourse has helped me by showing that aethertime needs measurement of both matter and action to define the universe just like S&Z use length and time. What is most interesting is that measuring matter is obvious with the IPK, but what about action?
Length and time are both differentials of light in time as frequency and wavelength times c, so of course the ratio of length and frequency. This eliminates time and provides pure action as the differential of time phase with spatial phase...interesting...
