On Jul 7, 9:40 pm, Immortalist <reanimater_2...@yahoo.com> wrote: > What sort of things are they if they are things? > > One natural answer is that they comprise continua, three-dimensional > in the case of space, one-dimensional in the case of time; that is to > say that they consist of continuous manifolds, positions in which can > be occupied by substances and events respectively, and which have an > existence in their own right. > > It is in virtue of the occupancy of such positions that events and > processes are to be seen as taking place after each other and > substances are to be seen in certain spatial relations. > > Or do space and time have properties of their own independent of the > objects and events that they contain? > > Did Einstein show, through his theory of relativity, that since space > and time can change in shape and duration that space and time are more > complex than just sustained perceptual constants? > > Metaphysics - by D. W. Hamlynhttp://www.amazon.com/exec/obidos/tg/detail/-/0521286905/
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.
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.