I remember a day way back in the 1970’s when our family was riding in the car on the way to a weeklong summer vacation in Washington, D.C.  On this nice summer day my father was driving and I was riding in the back seat of our Ford Galaxy wagon.  We were having a long conversation on how various mechanical things worked.  Since my father was a high school science teacher he knew a lot about things that interested me.  His explanation was always preceded by just one simple word from me:  “Why.”  I remember that after at least an hour of this discussion, my father started to become agitated as he would explain something, then I would ask “why” again.  This led to an endless spiral of a conversation that was soon terminated by my father!