Just for the fun of it, here's a counter element -- Why should we accept that there's life outside of Earth? We haven't encountered any sentient species and at most have found fossils of bacteria which may or may not be extinct. Is accepting that there could be aleins that far away from accepting that there could be Gods or some sort of psychic energy?
Poul Anderson has written numerous stories where humans are the only sentient life forms. Firefly never had aliens (nor sentient robots).
I posted something similar on another DB. I want to see a science fiction series completely set within the Sol system. Right now our current science tells us FTL is impossible (but we're working on it). Despite that, there are several locations right within our solar system that could be used as settings for a series. All nine, er, eight planets plus numerous moons.
Someone on that DB suggested Anime's "Cowboy Bebop." I've not seen it yet. I'm sure there are elements in that series that are beyond our current science but it was suggested because it's set entirely within our solar system.
Second, you want to use present understanding of science ALONE to describe a far future setting, where our understanding will have changed, probably a lot.
So this pining for "scientific purity" is kind of silly.
Why is it silly? We live in the 21st century. We're discussing 21st century entertainment. Why would it be silly for anyone to want to see a piece of entertainment that, while set in the future, still reflects and conforms to our current level of understanding?
Someone mentioned literature. There are numerous books out there that deal with science fiction in a more "hard" or "scientific purity" fashion. I'm reading Ben Bova's books at the moment. I've completed most of the "Grand Tour" series of books. It's great. Hard scifi completely set within our own solar system. No mental powers, no supernatural beings or cosmically advanced aliens.
On the other hand wanting or asking for some form of "scientific purity" doesn't exclude scientific advances unknown to us. Bova's been heavy on the practical use of buckeyballs, something that currently isn't being used all that much. Plus he's mentioned advanced or "exotic" building materials, fuel mixtures, etc... Plus Bova's "Grand Tour" establishes that there are microbial life forms on Venus and the moons of Saturn, an extinct sentient civilization on Mars and giant intelligent dolphin like animals lving inside Jupiter. He's presented all of these in such a way that the ideas sound scientifically believable.
Someone else in this topic suggested or mentioned finding a parallel in nature. Personally I find that a great tool. I guffawed and nearly choked when Aeryn Sun was able to carry a viable fetus for so long without it growing. Sounded far fetched to me until I saw that there are insects on Earth that do the same. If an insect can do it naturally, why can't man eventually find a technological way to mimic that process?
But does that get us back to psionic powers? Insects seem to communicate "telepathically." That's where we get the term "Hive Mind."
Perhaps the "scientific purity" qutoent can be satisfied by providing a psedo-scientific explaination for such things. Or at least point to naturally occuring parallels. Maybe this will make it less "pure" but it does keep it from sounding "mystical" or "supernatural."
