Quote Originally Posted by christopher leigh View Post
The universe pertains to all matter. Space is the relationship between things, and time is the relationship between moving bodies I.e. the earth revolving around the sun. So yes if only one particle existed then the concept of time would have no meaning.
I suppose what I am contemplating is that what if, if there are any are the boundaries of spacetime. Perhaps the effect that matter of our universe has to curve space time is limited and this could be a boundary.