DEFINES time travel as the act going into the past from the current date;
Here's your problem -- and I'm sorry to say it, but it could be a death knell to your proposal.
The concept of the "present" is a creation of the human perception of space and time, it doesn't exist, and differs between organisms and various forces of gravity. One famous physicist was once quoted saying (or writing?), "The distinction between past, present, and future is only a stubbornly persistent illusion." I don't actually understand this paradox because I don't study relativistic physics -- I just time travel like any commoner would --- oppressed with a sporadic present.
I also think the tralfamadorians would be absolutely confused and particularly irritated with this humanocentric resolution. Actually, they probably would just snicker at how much you think you know about the universe but don't know at all in this particular moment.






