Recently I read a suggestion of time travel, a notion popularized by science fiction. In reality, time travel is not something I expect to ever exist.
So, what exactly is time? Einstein proclaimed time as a dimension. But it has no similarity to the three dimensions we are so familiar with, or does it? Having taught physics for years I am often confronted with making some sense of a four-dimensional world to college freshmen in a simple manner, a way they can understand the explanation.