
Space Bridge?
Thought that needed technology we don't have yet.
Also though officially H sapiens does not have interstellar technology it is possible at least in theory, using something very much like a 'Gate in terms of needing a system at both ends and with the additional restriction of needing to be aligned both in space and time. So to get say 4 light years out is simpler than 400, or 40,000 and a connection may only be possible for a few seconds every century or so.
The base technology is similar to that used to entangle photons but using a lot more power and gravitational displacement effects similar to a countercurrent multiplier so it will work simply with extremely dense conventional matter moving very quickly.