On Jul 16, 11:38 am, PD <thedraperfam...@gmail.com> wrote: > From a physics perspective, "things" are identified by their > properties, where said properties are regulated, described, or > predictable according to certain systematic regularities called > physical laws. > It isn't really necessary to try to drop things into categories of > things in order to do that. Categories usually end up being broken > most easily in our deepening understanding of nature. Categories that > we think are mutually exclusive and/or exhaustive frequently end up > being neither. For example, it is tempting to call an electron a > particle, or to call it a wave, where we take those two things to be > mutually incompatible categories and into which the electron MUST fall > somewhere. This turns out to be a bad idea.
> However, it is perfectly > acceptable to describe an electron by its *properties*, especially > properties like electric charge, spin, parity, momentum, and so on, > which are of interest because of their role in physical laws.
Regardless of their role in the mathematical equations that are called "physical laws", what IS an electric "charge"; the electron has no "spin"; in what way and with what does an electron have "parity"; and momentum (mv) requires an electron to have mass=weight in any g- field.
> By this description, space and time are physical entities because they > have properties in their own right, and those properties are of > interest in physical laws.
Independently of anything in it, what are the "properties" of space? Independently of the mathematical properties of clocks, what is "time" and what are its physical properties?