Chapter Four is one of the easier chapters. The Tao is eternal and infinite, much like the universe itself (even if this "version" of the universe is not).
It is the nature of the Tao,
that even though used continuously,
it is replenished naturally,
never being emptied,
and never being over-filled,
as is a goblet
which spills its contents
upon the ground.
An interesting thing about astrophysics right now is the "unknowableness" of the beginning and endpoints of our universe. Was there another universe before this one whose contents were "crunched" together and then reformed in the Big Bang?
Will our current universe get "crunched" back together only to be re-formed?
Or will the matter of this universe drift slowly apart, so far apart that no particle is near any other and everything becomes the Void?