Earlier quoted context omitted.
True. But we have prima facie evidence that advanced civilizations -- as advanced as we're about to be, in not very much longer -- are very rare.
Do we have evidence of that? It seems like we've not looked in sufficient detail at a sufficient number of solar systems to reach a conclusion of "very rare".
Re: Mars rover is frozen in place following software error
#71I agree, absence of evidence is not evidence of absence.