Here is the Hand, here is the Eye.
I was thinking about aliens-- you know, I have a weak anthropic bias, & I don't mind admitting it. Clearly a strong anthropic bias is crazy nutso, but the chemistry behind saying something would be carbon based is just...strong. All those bonds! Water, so useful & tricky! Which isn't to say silicon couldn't come into play, or chemical processes that are opaque to me-- I took like, one very basic organic chemistry class a long time ago, so I'm hardly an expert. Enough to say-- like, left-handed proteins? Come on, like...spiders do that, practically. & silicon is like a crappy version of carbon; like I said, possible, but I wouldn't start with it unless there were no other options...except there are, & carbon is manufactured in stars, so it is relatively plentiful...anyhow, water is a little weirder, I could see ammonia as a solvent, or whatever. Otherwise, giant super-structures like cloud beings-- well, stellar soup could replace primordial soup, I guess? Macrocosmic structures? Space is big enough? I think carbon is the winner by a mile though. Call me a carbon chauvinist if you want. Those are four robust valence electrons!
Like I said, strong anthropic bias doesn't make any sense; there is no functional reason to look like an ape. There are reasons that the ape became sentient, though-- which I'd say boil down to hands & brain. At that level, well. The organic structures on Earth that I could see supporting sapience (not getting into arguments about sentience or sapience) are apes, cephelopods, bugs, & elephants. Theoretically I could see some kind of seal or dolphin with hands, but it seems like once you get into the sea those pretty invariably turn into flippers. & I guess I could see a tail-based manipulator, in theory, but I can't think of anything that actually does that. We've got a strong proof of concept in bipedalism, but I think radially symmetrical critters like starfish or octopi have a shot; bugs demonstrate that they can manipulate things collectively, & elephants have the best mouthpart manipulator that I can think of off the top of my head.
How do you get them up into thinking? Or rather, how do they evolve the need for sentience & eventually technology? Well, I think a good food source is important-- I'm a convert to the central positioning of fire to human evolution, allowing a big brain & all that. It maybe doesn't have to be fire-- a calorically dense soup of krill or I don't know, some other superfood could do it, couldn't it? Something that freed up metabolic space for a brain? Which doesn't pressupose a brain, though-- you need a reason. Looking around is one, sure. Is getting better at language another one? Lets skip that for a second & go back to fire. Is fire necessary for technology? That would mean everything has to stop being marine, has to be terrestrial & have oxygen to boot. I don't know that I agree. Glues, chemical burns, whatever-- I think you could get around fire. I don't think you can get around language, though. Maybe you can sneak past it by being hyper-eusocial & replacing language with genetic roles (genetic meaning whatever molecules you store your biological data in). Now we're starting to get out there, but that doesn't mean it ain't plausible. Space faring clump of octopus hiveminds? Why not!
This is what I think about while I sit at home with my wife. I bailed on the gym; after having so many guests over on TV Night & letting Danielle crash, we needed to recharge our batteries, & so we sort of collapsed into each other. Well, I was super collapsed, I was awfully needy. We ate noodles of various Thai varieties & watched television. First it was Castle, which was fun as usual, but is doing a steampunk episode next! Which cracks me up; all those "gothic culture" cop shows have beaten & misrepresented that subculture to death, & I think it is hilarious that steampunk might be next. Hilarious. We also watched "Must See TV" actually on Thursday, instead of leaving it on our DVR till whenever. 30 Rock was charming; at this point you expect it will be, so it really has to be, or it counts as a failure. I keep saying what a relief it is that Community finally admitted that Annie was "the hot one," since she clearly is, & that frees up a lot of the characters from patterns they were stuck in. That was enough for me, though, so I spent the rest of the night reading & then went to bed, where I dreamt of goblins & Tron in the context of supernatural home invasions. Today I just think-- isn't Vecna the best of all mortal apotheoses? Better than Hercules & Jesus & Buddha, for sure.