I don't watch Stargate. My conclusion is: either advanced technological intelligences are very rare or interstellar travel is impossibly difficult or both. IF advanced technological civilizations are not rare then it is probable that more than one would hit upon the idea of the Von Neumann approach to exploration. Imagining that all such programs were conveniently hijacked or 'misused' is simply silly.
Now, as to your lack of logic: B) There's a difference between "common" and "easy" or "quick". You postulate that if evolving species and advanced intelligence is common, it had to be quick too.
Quite the opposite. The universe is ~15 billion years old. You have (evidently) no idea of the time scale. As I mentioned, life began relatively quickly on Earth (~3.8 billion years ago) but modern life--including us--is the result of only the last 600 million years given Snowball Earth. Sagan's point--which remains valid despite all objections posted here--is that we are a newly-hatched technological civilization, only a century or two old. So we are the latest, arriving in the blink of an eye. Amazing hubris to believe we are the "first" or most advanced. Second-generation stars were probably quite capable of accumulating enough heavy elements, and many 3rd-generation stars are older than our Sun. The entire human race--all the way back to Homo Habilis--is only a few hundred thousand years old; another eye blink.
"I also find the notion that intelligence is the "intent", or "endpoint" of evolution to be silly. Sure, ONCE intelligence is introduced to a planet in a particular species, that species will likely dominate their planet, but you still need the freakishly unlikely set of genetic accidents for it to happen."
You make my argument again. Once more: "My conclusion is: either advanced technological intelligences are very rare or interstellar travel is impossibly difficult or both. IF advanced technological civilizations are not rare then it is probable that more than one would hit upon the idea of the Von Neumann approach to exploration."
"Now, GIVEN ENOUGH TIME, even the freakishly unlikely becomes likely. The odds of intelligence developing through random mutation is an unknown variable X. X could mean that there's even odds that it'll happen once in a million years, once in a billion years, once in a hundred billion years - we have no idea. X could be anything. You are assigning a low value to X based on zero evidence. Even -with- "billions and billions", it may -take- billions and billions of planets working for fifteen billion years to produce the first half-dozen or so intelligent civilizations."
Why do you insist on continuing to repeat me? Again: My conclusion is: either advanced technological intelligences are very rare or interstellar travel is impossibly difficult or both. IF advanced technological civilizations are not rare then it is probable that more than one would hit upon the idea of the Von Neumann approach to exploration.
"It may easily be that, given -another- ten billion years, there'll be a hell of a lot more advanced races out there, and we happen to be ahead on the curve. No one can know. But you're conveniently introducing your own timetable for the likelihood of such a thing occuring with zero data for backup beyond our own experience."
If this is so then we are alone. If we are alone (he said with a weary sigh) then either advanced technological intelligences are very rare or interstellar travel is impossibly difficult or both. IF advanced technological civilizations are not rare then it is probable that more than one would hit upon the idea of the Von Neumann approach to exploration.
--Boris