[tsimionescu]

> When dealing with complex questions of which we have but datapoints, the probability of scenario A vs B moves in a linear scale, not according to arbitrary requirements of "extraordinary evidence".

That may be true, but I the case of interstellar travel, we have mountains of solid evidence to prove it's not possible (essentially all of physics for the last 100 years or so), and some vague claims with 0 evidence claiming it's actually happening. To convince us that all that physics is wrong you have to bring some extraordinary evidence, not claims that you heard someone knows someone who saw something.

[mach1ne]

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.

[tsimionescu]

I should say not feasible instead of not possible. And this million years number comes with some massive assumptions about societal stability, the possibility of mining resources from lifeless planets etc.