[curtainsforus]

We observe causality in our universe and day-to-day lives. If FTL movement is possible, you might expect at least some particles to be doing it, and that there'd be closed timelike curves or causality breaking happening already in nature, and we don't.

It's not clear what 'breaking causality' would look like. It's like saying what if you made 0 equal 1?

[wruza]

Well that’s relatively easy. Some object (or particle if you like) appears out of nowhere and causes the events to happen that make it go time travel and appear out of nowhere and cause… you get the idea. Something caused the entire universe, before “time” was even a thing (or there is much more to it). Why couldn’t that something cause few events to cause themselves in an already “deployed” spacetime?

We observe causality

If we can’t observe something it may just mean it’s rare and/or hard to detect.

I understand that probability of me asking this first time is zero and people definitely brought that up and analyzed why this is not the case. I’m interested in reasoning and whether it’s just a rule, like conservation of information (is it so?), or if there is something fundamental preventing it completely.