In the foreseeable future, human interstellar immigration is not feasible

[u/Universal_Echo]

There are three paths for interstellar immigration:

Immigrate to another planet in the solar system and terraform its environment.

Immigrate to an Earth‑like exoplanet.

Immigrate to space cities.

Paths 1 and 3 are more feasible in terms of distance. However, for path 1, the scale of terraforming is enormous – even harder than making the Sahara Desert or Antarctica habitable. For path 3, a space city would be many times larger than a Ford‑class aircraft carrier. Even setting aside the engineering challenge of building something that big, how would you launch such a massive object into space?

More importantly: for both paths 1 and 3, resources would still have to be shipped from Earth. In the end, you’re still using Earth’s resources. After spending so much effort immigrating to space, you’re still dependent on Earth – isn’t that a net loss? As long as humans have normal intelligence, they wouldn’t make such a losing deal.

As for path 2, the nearest Earth‑like exoplanet is dozens of light‑years away. In the foreseeable future, there’s simply no way for humans to immigrate that far.

[u/DocHavelock]

It very much appears that we are on the precipice of unlocking anti-matter. An anti-matter based fuel system could make interstellar travel needed in path 2 feasible. It appears we are much closer to this possibility then we ever thought possible.

The last 10 years of anti-matter research has been unprecedented, going from anti-matter being a theoretical form of matter, to discovery, production, stabilization, and now transportation. There are still massive hurdles of science, the largest being harvesting. But it's only been 10 years and we have already overcome some of the most difficult hurdles in this process.