With that kind of propulsion politically available, I doubt finding workable combinations of mitigation strategies to interstellar medium hazards would be the showstopper. Especially not one to hold us back for time scales that oceans did. Getting humans interested in prioritizing projects like that, to me, is the real headscratcher.
We could put people on Alpha Centauri in 88 years with 50s technology like Project Orion. The really hard part is figuring out a way to make us use the technology we do have for things like that, instead of for bombing each other back to the stone age.
It was a lot later (1300s), but Ibn Battuta seems to have done just that. Guy leaves Morocco and just keeps going on and on, till he ends up in China. Though perhaps even more incredibly he actually does come all the way back. The historicity of his accounts is disputed and maybe only a part of it is true, but even if he only got as far as India, I still find it fascinating to imagine doing at that time.
If this was one of those 3D maps, there would be a a spike for Naples reaching into the skies
You wouldn’t want to become lost in there!
Cries in anjin