by Seth Shostak
Senior astronomer at the SETI Institute
It's 150 years into the future, and Homo sapiens has managed to eradicate all of Earth's native flora and fauna. But for some reason the nature-free lifestyle of our great-grandkids still requires that we import "unobtainium," a mineral of unspecified application that's worth $20 million a kilogram. Even crack isn't that pricey.
Obtaining unobtainium is the motive power behind "Avatar," the James Cameron movie that's broken all records for production costs, requiring upwards of a half-billion dollars, or the same as constructing the Empire State Building (after adjusting for inflation). In the film, Earthlings of the future have set up a mining operation on the jungly, predator-infested moon, Pandora, to extract this costly material and send it back to Earth. That sounds like just a bit of innocuous economic activity, but Pandora's locals (the Na'Vi), who look a lot like willowy half-dressed fashion models sporting stripes and a blue hue, are not copasetic about having an extractive industry on their home turf. Trouble ensues.
Everyone raves about "Avatar's" visuals, although the film's story line has taken some lumps in the press. Often described as "Dancing with Wolves" meets Pocahontas (Britain's Daily Mail dubbed it "Dancing with Smurfs"), speculation is rife as to whether this megapicture is going to save Hollywood or snuff it. The scale and production values of "Avatar" also raise various, and interesting ancillary issues. For example, are movie actors destined to endlessly emote in front of blue screens, suited up with motion-capture reflectors? Are real people too limited to actually appear in films?
And then there's the question - which seems to resurface every half-century - of whether movies and television are finally going to switch everyday production to 3-D? I'm a big fan of this technology, and as a kid persuaded the Polaroid Corporation to send me some sheets of polarizing material so I could make and project 3-D photos. But honestly, I find that I'd much prefer that stories have imaginative rather than spatial depth, and 3-D can become a distraction both for the producer and the viewer. Processing that stereo information requires effort on the part of both your corneas and your cerebellum.
But to the point: Since James Cameron is besotted with space science, it's always interesting to see whether he gets it right in his films. His previous blockbuster, "Titanic," was meticulous - some would say obsessive - about historic detail. "Avatar" is less attentive to accuracy - or at least, plausibility. One could easily bemoan the fact that the turquoise natives are remarkably anthropomorphic, or that the atmosphere clearly has oxygen (you can set fires) but is nonetheless strangely toxic to humans.
Also puzzling are the lovely skyscapes, showing Pandora's home planet (a doppelganger for Jupiter) and at least three other moons, hanging around together like an urban gang. Cameron hasn't studied orbital dynamics, clearly, for otherwise he'd know that moons don't cotton to such close companionship.
Then there's the idea of an entire society living in a tree - seemingly peaceable, laid-back, and adept at riding big, bird-like lizards (what is in that atmosphere, anyway, that it can support flying creatures the size of a convenience store?) Yet, despite their pastoral ways, the Na'Vi, armed only with bows and arrows and an occasional herd of hammer-head hippos, can deploy like Special Forces, and engage with Marines of the 22nd century. Seems modestly implausible.
Perennially wrong
As I said, I could go on. But my critics will accuse me of nitpicking, and really - since I greatly liked the film - is there any point to saying that a fictional story is, well, fictional?
Maybe not, but I do want to note something about the premise, because Tinseltown has used the idea of interstellar mining over and over. Simply put: Is there some naturally occurring element or compound that would really be worth hauling back to Earth from another star system?
This question was addressed two centuries ago, when England began to send people (mostly low-grade criminals) to Australia. This population needed something to export to London to earn foreign currency, and they settled on wool. This was not because the Aussies are particularly fond of sheep (although New Zealanders have plenty of jokes about that), but only because wool is very expensive per pound. Sending it back to Europe was expensive, and Australian wool would only be competitive in the London markets if the shipping costs were a small fraction of the product value. Even in the day of wooden ships, this criterion was met.
Now let's consider the tariff for sending a kilo of unobtainium back to Earth. Our descendents in this film have some pretty nifty looking rockets, and we hear shortly after the opening titles that the trip to Pandora takes only about five years (as measured on-board). Well, even the nearest other star system, Proxima Centauri, is 4.3 light-years from where you're sitting. That means that transport between Earth and Pandora occurs at 85% the speed of light or more!
Getting a kilogram of unobtainium (or anything else) up to that speed, and then decelerating it at the end of the ride, takes at least 10^17 joules of energy. That's freshman physics. What's the cost of that energy? Our cheapest joules are supplied by your local utility company at about ten cents a kilowatt hour, or 36 million joules per dollar. At that rate, the price of shipping a kilo of unobtainium works out to $3 billion, or - assuming 2% annual inflation between now and 150 years from now - $50 billion in 2154 c.e. dollars (that's the year in which the film takes place).
In other words, the transport costs for unobtainium exceed the value of the merchandise by a factor of more than 2,500!
So that settles that. You are not about to pay $60,000 to Amazon as the shipping charge for this month's best seller. Interstellar mining -- and the affront to natives it might imply -- should be tactfully removed from Hollywood's box of tropes.
About Dances with Ferngully or Pocahontas with Smurfs or whatever - I find it amusing that people would endlessly echo these notions while at the same time chiding someone else for lack of imagination. They should at least come up with an original accusation. For instance, Avatar is clearly a rip-off of my own 2001 production, "Dragonglide". In both, winged dragons fly around surreal 3D landscapes. In both, red dragons are much more badass than the others, and prey on them. The more I look, the more parallels I see. I don't remember there being dragons in Dances with Wolves, or in Pocahontas. Mr. Cameron obviously played my game and liked it so much he decided to make a film of it. To make matters worse he even has a game based on the film. I look forward to receiving a large cheque in compensation. ;-)
Pandora has a lower gravity and a twenty percent denser atmosphere than Earth, hence the flying behemoths. That atmosphere contains oxygen, but also hydrogen cyanide and other substances toxic to humans, hence the need for face masks which filter those toxins out.
Given the smallness of most moons relative to their primary, Earth's moon could be dismissed as an improbable fiction if we didn't actually see it. Also, moons of moons could be commonplace elsewhere. Not everywhere is the same as here.
On the anthropomorphicity I'd guess Pistachio is right. Humans first arrived on Pandora more than 30 years before the events of Avatar. The Na'vi have short lifespans - the hybrid Avatar clones reach maturity in just three years. Eywa could easily have populated Pandora with a synthetic species over the course of twenty years or so. Other species were apparently designed to stomp humans, just in case diplomacy failed.
On IMDB you'll read viewer-submitted comment about bloopers like how at the end the humans weren't wearing masks outdoors (but of course they were).
A lot of effort went into designing the background details. Armies of experts were consulted. It's unlikely that the plausibility failures everyone imagines they see would have been overlooked in that process.
The atmosphere's obviously oxygenated, but there must be some toxic component. I have no idea what. A few hundred ppm of HCN would fit the effects on people.
Those ships might be fast, but they're not using some imaginary FTL drive. They look like Pellegrino's Valkyries. Valkyries are antimatter fuelled. I'll accept enormous solar-powered antimatter factories built by self-replicating machinery, put the Von Neumann seed for one in close orbit around Alpha Centauri B and there's your fuel. They don't mention this in the movie, but I don't usually mention the gas station when I'm driving my car.
Unobtanium looks like a room temperature superconductor. Given those (presumed) factories generating fuel at near zero cost, shipping it back to Earth suddenly looks like a bargain. You still have to assume it can't be manufactured at a reasonable cost back home, of course!
As for the big flying creatures, it's never mentioned what Pandora's gravity is. It looks approximately Earthlike, but it could be a fair bit less. And the atmosphere could be substantially thicker.
And as for the native creatures deploying like special forces... I thought that was the whole point of the ending. The entire biosphere of Pandroa is conscious but it took a while for the worldmind to notice the alien infection and mount a proper immune response.
All in all I thought Avatar was admirably hard SF for the screen. Even 2001 involves technology indistinguishable from magic.
The formatting comes out wrong. Readers will think you mean a number slightly more than one thousand, when I believe the author means ten to the seventeenth.
Editor: please fix - you are off by a factor of one hundred million million.
Also, it is mentioned that Pandora has lower gravity than Earth (head military guy mentioned it when pumping iron, something to the effect of "this low gravity can make you weak" or some such). Although since they weren't bounding around like Neil Armstrong, it can't be THAT much lower than Earth.
No doubt some of Aesop's critics grizzled about the silliness of a tortoise and a hare having a race.