Makes me think of this Asimov classic where you really can change the past

https://archive.org/details/dli.ernet.526852/mode/2up

where it makes sense because people established an orthogonal dimension of time and this movie

https://en.wikipedia.org/wiki/Predestination_(film)

based on another Heinlein classic

https://en.wikipedia.org/wiki/%27%E2%80%94All_You_Zombies%E2...

where you can't because it's all just a knot.

they’ve all gone 4025, where the real party is.

Future people will have a Holodeck to simulate the past. No reason to actually go there.

Maybe they are all mostly dead and ever-more-feral survivors ridden by the radiation- and pollution-borne crippling genetic sicknesses are birthing still-born and slowly dying out while picking through the debris left from the civilizational collapse caused by global warming, ai, and the resulting world wars.

And the last stronghold of civilization are warlike and numerous but illiterate Tate descendants in the mountains of Romania, unable to build anything more advanced than a cudgel used in the rituals to determine the alpha leader.

time travel backwards is impossible. but there are undoubtedly time travelers from the past going forward in time

Looking at the actual link itself, is this one of those papers that takes a thought experiment and tries to evaluate it using abstract mathematics/statistics? That's what it looks like it's doing. How is it actually useful to apply Markov chains to such unknowable suppositions? Is this analytical philosophy