1, achieving superluminal flight.
I believe everyone is familiar with Einstein's superluminal theory. If humans can fly faster than light, they are likely to reach this planet. At present, humans calculate the distance between planets in light years, but if superluminal speed can be achieved, it will be faster than light years in principle.
2. Realize space folding.
Einstein also put forward a theory, that is, the theory of space folding, just like a piece of paper. If it takes us a minute to walk from one side of the paper to the other, we can fold the paper, which may be achieved in one second. The theory of space can be realized in principle, but our current scientific level is not up to it.
3. Realize space crossing.
Generally speaking, the ability to travel through space will appear in many science fiction novels, but from a scientific point of view, this situation is really possible. There have been many unexplained space crossing phenomena in history, but I think this technology has not been solved scientifically.