Interstellar travel is possible even with the physics we know. A sub-light civilization could colonize the entirety of Milky Way in a million years or so.
The question is what the probability is for an intelligent species to evolve per solar system, and the more complex questions of how long they would survive etc. We only have a single datapoint (us) which only gives us the knowledge that intelligent life can evolve, but no direction whatsoever as to its probability.
The question is what the probability is for an intelligent species to evolve per solar system, and the more complex questions of how long they would survive etc. We only have a single datapoint (us) which only gives us the knowledge that intelligent life can evolve, but no direction whatsoever as to its probability.