And, should we put a line of spaces between each paragraph? Well, I am guilty of breaking to two space rule almost all the time. It is something that is old fashioned perhaps, but I does give one a chance to breath. The single space rule is really not a rule you need follow. It may be fine in a rush rush civilization to leave out the extra space, but do you really care or is it an obsession with typology. Do you notice the double space when it occurs?
http://www.slate.com/id/2281146/
Time is, was and will be. Without time we would not be. What a load it has to carry! Time seems eternal! You might even ask whether cycles in time exist? If so read Roger Penrose's book on new attitudes in physics towards possible "Cycles in Time".