Why Time is Future Oriented
  We assume that the universe consists of clusters which in turns have sub-clusters and the sub-clusters have sub-subclusters and so on. Confining to three-dimensional space, it is shown that the universe is expanding if entropy of the universe increases. It is also shown that clocks slow down when time progresses towards future. Our model also justifies the big bang theory. 
Shahid N. Afridi and M. Khalid Khan