While I agree with your assessment of known modes of travel, this also assumes we know everything. I believe it is a safe assumption that we do not. There are

While I agree with your assessment of known modes of travel, this also assumes we know everything. I believe it is a safe assumption that we do not. There are potential modes of travel via worm holes or similar inter-dimensional transits that could account for vast distances shrinking to zero without violating our known physics laws.