Thank you for the very long and detailed reply! I do understand that our current understanding of spacetime makes it impossible to do interstellar travel.

I have a background in physics, and although I ended up switching to a different field, there is some fundamental aspects of the field that it helped me understand. The most important one is that it is not an absolute truth, it is the best truth we came up with based on our interpretation and modelling of reality. So I am always careful with tossing around words like "impossible".

Yes, all those hard limits make it impossible for our generation, the next, and probably 4, 5, 10 or 20 more down the line to even consider it. I unfortunately do not remember enough of my uni days to give out examples, so perhaps you can help me here... Brilliant minds in the past have proven that some things considered impossible by the understanding of physics at the time were actually possible.

Now, yes, anything with spacetime manipulation today is conjecture and science fiction, and again, I'm not saying we'll be travelling to even the closest neighbouring star system anytime soon. What I am saying is, we don't know that much about spacetime yet. We know some, we have proven some, but not much. My point is: We have found so many ways around impossibilities that I doubt that (if our civilization doesn't collapse under its own collective stupidity) we can't find ways around these ones too, wether it's in 200 or 2000 years.

Edit: Of course there are some things we'll probably never do. We'll probably never go below the absolute 0, we'll probably never go close to the speed of light either. But that doesn't mean we can't work around these hard limits to achieve goals that they are gating.