Paradox-free time travel is theoretically possible

A gun merely jamming solves nothing.

Either the time traveler was there "the first time around" or he must be stopped from going back somehow. Because the first and the second time around must be exactly identical.

https://www.frontiersin.org/articles/10.3389/fphy.2020.00139...

Would you be aware of some force stopping you from performing an action that would change your motivation to time travel in the first place? For example, if you tried to walk up to yourself in the past, would it feel like some force field stopping you? Or will it be false sense of agency, where you suddenly make the decision not to do something? Or will some event happen to simply kill you? Or will you suddenly vanish from this timeline to live out a life you over-wise would have based on the consequences of your actions?

If we are a result of a series of tiny influences from our environment, will the entire past refuse to be changed? Or will you be able to live out a version of a timeline where a different set of tiny influences add up to the same future where you make the same actions? As a result, does that also limit what you are actually able to do in the past without changing so much that one of these alternative states is impossible?

If the past doesn't want to be changed, how about the future? Just because we perceive the clock running in one way, doesn't mean that it actually does. I would think that if the past must happen in some specific way, then the present will always occur and so will a specific future. Whilst we claim to experience free-will, we have so far not measured it. I guess this is really the idea that the quantum realm simply consists of hidden variables that are only perceived as 'random', rather than actually having any form of random element.

One thing I find curious is how different the models for time travel usually are.

In American media, it seems more often than not, time travel is modelled as if the past and the future are simultaneously existing parallel worlds, where the future is affected by the past in "real-time", e.g. Back to the Future's Marty gradually fading as the chances of his birth diminish, or Timeless's people in the future "watching" people arrive in the past and making sure their own team leaves "in time" to catch them.

These models don't really offer a solution to the grandfather paradox.

In anime however, time travel is near universally modelled with timelines, where time travel essentially creates a new parallel world each time. If you travel back in time and kill your grandfather, you simply create a timeline in which you were not born, but can continue to exist, because you are from a timeline where you were born.

I'm by no means suggesting that either model is unique to America/Japan (Rick and Morty for example uses the branching timeline model), I just find it interesting how they differ.

[1] https://en.wikipedia.org/wiki/Steins;Gate_(TV_series)