Back to the future in a crystal ball

Several years ago, yes several, some friends and I were sitting around after watching Back to the Future, for the umpteenth time. It's one of my favorite movies, only falling a few slots behind The Outlaw Josey Wales.

We talked about having a time machine and whether you had one choice – go backwards and return or for forward and return. It turned into a strange conversation.

If you went forward and found out some terrible things could you come back and make corrections to prevent those terrible things from happening? If you went backwards and could come back what would you do? Most of us like...