No matter how much we enjoy the metaphors of “Star Trek” and “Star Wars” and the like, one thing is certain: time travel is a fantasy.
We will never travel in time.
The concept of time travel states that somehow we can go “backward” or “forward” in time.
For example, a person living here in 2006 could travel not just to a place but to a time, like to the year 2050 or 1950, according to the fantasy of time travel.
But, of course, that is a fantasy.
And the reason it is a fantasy is because of the misuse of the word “time” travel for the word more applicable to the matter: clock travel.
And when we appropriately replace the word “time” with the word “clock”, we immediately see the fantasy in the concept.
A clock measures motion in increments of time, just as a yardstick measures form-substance size in increments of space.
An object so measured has dimensions of space according to the standard measuring device: the yardstick.
An object so measured has dimensions of time according to the standard measuring device: the clock.
An object can change in yardstick size through space over clock time as it moves.
When we say that an object travels we mean that it changed. Change is measured by the standard yardstick and clock in increments of space and time.
We say that the object, in changing, traveled through space and time.
We say “traveled” as a metaphor for the object’s change.
But the intervals of time measure, like the intervals of space measure, have no “forward” or “backward” quality to them. 
The concepts of “forward” or “backward” in either space or time is a human constructed relational, existing only in the mind of the observer.
Outside of the mind, there is no such thing as “forward” or “backward” with respect to space or time.
There are only interval comparisons which we use to assign meaning in a number of ways.
That meaning is only meaningful to us in our mind.
Thus, since space and time intervals only exist outside the human mind in a holistic instance sense, without a “forward” or a “backward” quality to them, there can be no “time” travel “forward” or “backward” through “time” outside of our mind.
Only in our mind can we turn the clock forward or backward … and once we look outside of our self, we find that our changed clock within us does not match the standard clock outside of our mind.
Thus there will be no escape of death by traveling “back” to the “past” and being a kid again.
And there will be no escape of death by traveling “forward” to the “future” for some fountain of youth medicine.
“Time Travel” “forward” or “backward” remains merely an error of logic, a fun science fiction metaphor for “a second chance”, … and a sometimes lovely thought when the real moment leaves a bit to be desired.
The universe doesn’t speak English.
