Space Adventures with A0117
The following is a correspondence I had with a redacted individual today. She's thinking about writing a time-travel story or essay with a science bent (I think), so to help her I rambled inanely for about an hour. The 1 and 2 are referring to her questions, which I omit out of laziness. Feel free to guess what they might have been.
You're using ""science"" too broadly here again, but this is certainly where time-travel has the potential to be an entertaining medium. Does it manifest itself presently by rewriting the world narrative in "real-time" (ie you could, from the safety of a "causal neturality" zone in a lab or observatory, watch as what someone does in the past impacts the world around you)? Do we discover, when things don't seem to change much as the tiles of the past are shuffled, that the butterfly effect is not merely overstated but that chain reactions are not real in a macroscopic sense? Kinky. But those ideas are for trippy Bruce Willis-shooting-Joseph Gordon-Levitt-in-the-face action thrillers.
The fundamental question you've come here to ask is: what kind of time travel is the most fun to write about while wearing a white coat? I hope so, anyway, because that's what I'm going to type about here until I take a nap.
Take your basic lab rat. White, fluffy, filled with hate for you and his cloned brethren. His name is A0117. You can call him A0, for short. Or Jared. He doesn't respond to his name (yet(?!)).
Time Scenario 1 (origin point):
Jared wakes up at 9:00, 9:01, and every subsequent minute all day to run a maze that slightly varies to test for the impact these differentiations have on his decision-making process, with the end goal of hopefully selling more laundry soap. Jared is "originated" at the start of the maze, meaning that his exact form (his body and his rat brain filled to the brim with hateful memories of everyone and thing he's ever come in contact with) is remembered on a giant VHS tape and can be recalled to this exact point in the future by a time machine that will reconstitute all matter that formed him in that moment from wherever it is (breathed out in the air, rubbed into the cage) back to the origin point.
Obviously (or maybe not obviously, it's your story after all), the longer Jared runs around and adds chaos to his original form, the harder the time machine has to work to put him back. The energy required for this is exponentially greater over time, so once Jared is originated he has to be recalled every minute to keep the power bill from running too high.
And then it turns out JARED'S A PERSON!!!(?)!
Time Scenario 2 (preconstruction):
Jared wakes up at 9:00, 8:59, and every previous minute all day to run a maze that must be built to satisfy his decision-making processes, with the end goal of hopefully selling more laundry soap. Jared was created by modelling a white, fluffy rat filled with hate for you and his cloned brethren in a fancy new version of AutoCAD. This model is exported to a giant VHS tape and Jared will materialize at the front of the maze when a time machine manipulates pliable matter from the spacetime continuum in order to "pay" for Jared's construction now. These calculations to find pliable matter are performed to reduce the strain on the fabric of the spacetime continuum from this process (it is revealed in a stunning CGI graphic starring Neil deGrasse Tyson that all of causality "tugs" at the fabric this way). The more matter you take, the further into the future the machine has to go in search of spacetime to harvest, and the harder the machine has to work to preconstruct Jared. The energy required for this exponentially increases by mass.
"That's not time-travel!" you protest thoughtfully (but incorrectly). Ah! There is a way to dramatically reduce the energy costs of tugging at the STF. Suppose the time machine locates a white, fluffy rat filled with hate for you and his cloned brethren that it can harvest from in the very near future? Almost as if...IT WAS/WILL BE JARED???? This sounds like it would be a recipe for time rips all over the place when some sly scientist steals Jared from the maze after preconstruction, foiling the time machine's pay-forward plan! You probably thought of that because you forgot the time machine would "know" that's going to happen. This machine is necessarily predicting the future to work and, in an important way, provides a screen of certainty for your research; if something is going to go wrong, the machine won't work. Provided its modelling software works correctly, of course, but presumably this story needs a conflict and that sounds like a pretty good one.
And then it turns out Jared's a person, which isn't as great a plot twist the second time around but still helps with turning this into a major motion picture.
I'll come up with more scenarios later, maybe. I apologize for not actually helping you with this endeavor in any meaningful way, but I do need a nap.