If there’s one thing science fiction fans might agree on, it’s that we long for another world. That’s what James Cameron has given us in Avatar: a gift to anyone who takes science fiction seriously. I really feel as if I’ve visited the planet Pandora, and I didn’t even see the movie in IMAX, just in regular 3D. Avatar is the closest I’ll come to visiting another planet. It was an exhilarating trip.

I’ve been wondering whether any movie could justify the eight gazillion dollars lavished on Avatar, but damn if every penny isn’t up in there on the screen. This is a real world, so fully realized that surely geologists, biologists and cognitive scientists were onboard. All the creatures who populate this lush world are clearly products of their own separate evolution, evolved together and related to one another. Even the mind-blowing physical aspects of the planet – the impossibly tall trees, the gravitational anomalies – are the result of the solidly realistic facts of Pandora: its gravity is lower than ours; it orbits in the shadow of a massive gas giant (which would make things gravitationally and magnetically different). Pandora feels real.

It’s all so awesome that I found it easy to forgive the fact that the story, also by Cameron, takes few risks: It’s a straightforward narrative we’ve seen many times before, with just a few cheesy or obvious moments. It’s Dances with Wolves, basically – and I don’t mean that as an insult. Jake Sully (Sam Worthington) is the soldier going native on Pandora, a Marine who’s been paralyzed from the waist down and given the opportunity to take over a job his identical twin brother, a scientist, started, and cannot finish because of his untimely death: Inhabit a body, an avatar, cloned from the DNA of both humans and the natives, the Na’vi, and go amongst the Na’vi and learn from them. The avatar bodies are keyed to particular researchers – Jake’s the only one who can fill in for his brother.

We humans are on Pandora for all the reasons we’ve ever gone anywhere: to take what we want, in spite of what the people who are already there may have to say about that. So, if there’s a Na’vi village right atop a hella big cache of the “unobtainium” the humans are keen to get their hands on, well, the natives – “savages” and “blue monkeys,” as the mining company twerp (Giovanni Ribisi) in charge likes to call them – will have to go.

Jake is exuberantly enjoying the freedom of his new Na’vi body – 11 feet tall, blue-skinned, and at least as athletic as Jake himself would have been – and learning about life among the Na’vi from warrior princess Neytiri (Zoe Saldana), who initially sees him as an ignorant child. Much that’s new in Avatar is concerned with the idea of how inculcated we all are to ways of thinking. The scientists on the planet, led by Dr. Grace Augustine (Sigourney Weaver), are initially skeptical of Jake, since he hadn’t been trained in using the avatar or in the Na’vi culture, both of which his brother had studied for years. The military protecting the mining colony, led by Col. Miles Quaritch (Stephen Lang), assume that Jake, as one of their own, will work as a double agent, gathering the intelligence that the humans need in order to undermine the natives. All the assumptions at work are so taken for granted that no one can see past them. As Moat (CCH Pounder), the Na’vi shaman and Neytiri’s mother, explains to Jake, “We have tried to teach Sky People [that is, the humans]. It’s hard to fill a cup which is already full.”

Jake’s cup will be emptied, and refilled, and by the inevitable showdown between human and Na’vi occurs, yours may be, too. For the Na’vi are entirely sympathetic – Cameron created them via motion-capture-assisted CGI, with human actors supplying the performances, and as completely realistic as their environment. Cameron has solved the problems that had rendered organic CGI characters dead-eyed and unwatchable. Not that the Na’vi are perfect or their world a paradise; Pandora may be beautiful, but it is rife with dangers. It’s just that they’re different, in ways that humans cannot even begin to conceive of until we – through Jake – become part of them.

AVATAR (4) • Directed by James Cameron • Starring Sam Worthington, Sigourney Weaver, Zoe Saldana • Rated PG-13 • 162 min. • At Century Cinemas Del Monte, Northridge and Maya Cinemas.