>>Did anybody ever tell Carl Sagan that for such a supposedly
>>brilliant guy, his thinking was very muddy when it came to UFOs
>>and possible visitations by an extraterrestrial civilization?
Probably he was laughed at by some, while others agreed with his assessment. His thinking is only "muddy" from the perspective of the person judging him.
>>His two assumptions—that there may be millions of civilizations in the
>>universe but they can’t come here, and that it’s because our planet isn’t
>>special— both assumptions seem to be patently stupid.
And... why is that? We don't know either way if there's many civilizations, or none... And, when we look into the cosmos - what sets a planet apart? We've discovered dozens of "Earth-like" planets without truly knowing if they *are* Earth-like... we don't know if they're special unless we can get there.
>>It’s a stupid mindset that mainstream science seems to become
>>infected with, as it’s not logical to assume that because our science
>>says that faster-than-light (and by implication, star travel) is
>>“impossible,” that all other civilizations agrees with that assessment.
Debatable... we're looking at it from the peak of our technology and understanding of physics. While it may not be correct - at the moment it can't be considered 'stupid' until more discoveries are made to the contrary.
>>If anyone could ask a scientist from the 17th century would it
>>be possible to see moving pictures on a small box of things
>>taking place a continent away, not knowing about radio waves
>>or electronics, that scientist would say it’s impossible.
Or... witchcraft. But, I agree - he wouldn't think it would be feasible, from the height of his knowledge. But it's also arguable that the things we knew of then were in a much smaller 'box' than what we know today. While he didn't know about radio waves, we're aware of more physical laws and theories that are much more difficult to overcome. While our abilities and knowledge are greater today, the hurdles we have seem much higher.
>>He’d be wrong. He’d say that it was impossible to fly across the Atlantic in a few hours.
But... at the same time - the concept **of flying** is one he'd know and understand. While the ability wasn't there, the physics behind it would be somewhat understood. As opposed to exceeding the speed of light - which implies that it would take more energy than we're currently capable of producing.
>>There would be a long list of impossible things that we do now every day.
We *do* have a long list...
>>What a difference a few hundred years makes to one’s way of thinking—and to
>>technology. So why did Sagan think that every civilization in the universe is at
>>the exact same level of technology we are? Or has our limitations?
I'll bet he didn't make that assumption; but I'll bet he did think they were limited by physics the same way we are. Unless we have an understanding of *how* moving faster than light is possible (which we don't) - then the concept of moving faster than light is a difficult one to accomplish.
>>Billions and billions of stars, and not one of them anywhere has a civilization
>>hundreds or thousands of years more advanced—not one of them found away
>>around relativity? Right...
While we have no way of knowing this... It's fair to say what obstacles we have are the same as any other civilization - Sagan (and the rest of us) don't know of a way to apply enough energy to a mass to move it faster than light. There may be a civilization exist that has solved this problem - but... I have to doubt it for two reasons: First, because I'm not sure it's something that can be solved, and second - they haven't made it *here*.