Avatar's dark forest - part 1

Diamond-hard science-fiction

When evoking the 2009 film Avatar, people may remember beautiful visuals, heavy-handed exposition, then-bleeding edge special effects, a hippie message with the subtlety of a terminal-velocity anvil, nice-looking combat scenes featuring the worst cavalry tactics since Agincourt (from Poland the Na'Vi are not), Pocahontas IN SPAAACE, one memorable dedicated villain, and yet another bland hero to out-native the natives and lead them against Big Evil Corp.

All this is hiding a subtler, bleaker and more interesting narrative, in one of the hardest-SF stories ever featuring aliens.

Hard SF? Really?

A bold claim for a film with Space Blue Elf First Nations, but special care has in fact been given to keep everything as realistic as possible.

For exemple, let's look at one of the very first shots of the film:

The ISV VentureStar (source)

This may be the most realistic spacecraft from the entire history of film-making. In fact, it has a feature almost any type of spacecraft needs but that I have never seen elsewhere in any film or show ever: radiators. Specifically, badass giant red-glowing radiators to evacuate the massive waste heat produced by the kind of reactors a starship needs (and give both cool visuals and, in other works, potential plot points).

While looking strange and completely unlike common SF starships, it feels believable and actually made for deep space - and that's because it is. It has been designed by actual astronautic engineers as a workable antimatter interstellar slower-than-light transport starship based on known science and what engineering could be developed once enough time and resources are sunk into it. This very design may well be built someday for interstellar missions.
In fact, we could start working on it right now if we had enough industrial capacity in space (or enough rockets to launch said industrial capacity in orbit) and a more efficient way to produce and store antimatter. Two things that we know we could solve if enough time and money was dedicated to it.
And if we learned about the impossibly vast amounts of money to be made by mining Pandora (more on that in the next part), the investment would probably be made - Avatar is the rare bird where even economics make sense.

One may wonder who in their right mind would give such a ridiculous name to such a technological marvel of space engineering, but there is precedent: VentureStar was the name of a promising Space Shuttle replacement program in the 1990, killed by politics after billions were invested. Had it been completed, it would have in fact borne an outward resemblance to the Valkyrie shuttles used for orbit-to-surface movement (we can see one near a docking port of the starship). After all, there are few known possible shapes for Single-Stage-to-Orbit shuttle crafts.

This name is one of those cases where reality doesn't have to make sense the way fiction does.

Similarly, in lieu of the more outlandish designs that are common in soft-SF, human vehicles and weapons are grounded in reality. Weapons are variants of today's firearms and rockets. Flying vehicles are using existing technology, if more refined engineering. For example, ducted fans have advantages but are difficult to make at those dimensions and power levels. With lower gravity and higher atmospheric density in addition to advanced manufacturing techniques, they become a justifiable choice.

Lower gravity + higher air density + no need for heavy armour = cheat mode (source)

Mech suits are often glaringly unrealistic, but in this particular case, they make sense.

The main problem with bipedal vehicles is the unbearable pressure at the leg joints: as a biped is made taller, the weight supported by the joint, depending on volume, grows faster than the surface of said joints supporting it. This is why, on Earth, sea creatures can be much larger than land animals that have to use legs. Here, this problem is avoided in two ways: the AMP suits are reasonably small, and gravity is lower.

As to why use legs in the first place, legs are much more useful than wheels and threads in the uneven terrain of a jungle, and they can move faster and take less room than a multi-legged spider tank, while flying is energy-consuming and cause a nasty, noisy downwash.

Those suits are in fact used not unlike what is anticipated for exoskeletons today: for transporting heavier weapons, and for moving heavy charges around - a deceptively important job for any army. They are also useful for their enclosed cockpit and life support, allowing for greater autonomy and better environmental tolerances than portable gas mask and bottles. Air conditioning seems particularly useful in such a place.

Actually a good idea (source)

Let's pay attention for a moment to the gas giant Polyphemus hanging behind the world Pandora in that shot of the starship. You will note that, in all shots for a given location, it is always in the exact same position in the sky. This is because Pandora is not a planet but a moon orbiting said gas giant, and as astronomers will tell you, such moon will always en up tidally locked, like the Moon is around Earth: the same side is always facing the orbited body. As such, the same way the Earth is always at the same position for a Moon-dwelling astronaut, Polyphemus lay immobile in the sky of Pandora.

This is especially visible when seeing distant lands, where the gas giant appears at a very different angle in the sky. Even without knowing the details of orbital mechanics, this change reinforces the impression of great distance already given by the very different biomes replacing the jungle. This is an interesting example of an obscure (to the audience) point of realism being used for great visual narrative effect.

Similarly, the environment appears believable because for the needs of the film, actual biologists came up with its elements and did their best to create as realistic a forest ecosystem as they could - but more on that below.
The always interesting Sci-Fi Interfaces (one of the inspirations for this blog) has yet to publish articles on the user interfaces of Avatar, but at a glance, they seem to be equally believable.

(For the sake of this analysis, the tomfoolery of quantum entanglement superluminal communication will be ignored. At most, we could suppose that the popular but utterly wrong explanation of how the system works has been propagated by shoddy, sensationalist journalism instead of, say, wormholes, and leave it at that. It is still diamond-hard SF, even if there is a chip in said diamond.)

Why is that important?

This is capital to determine the narrative contract between the author and the audience.

Now, the narrative contract is a rather grandiose-sounding for how the audience is determining what kind of story the work is about and building expectations based on it. For example, if you are reading gritty detective fiction set in the 1930, the narrative contract states that the story is set in a realistic historical environment. So the protagonist should not pull a smartphone and check on Wikipedia when needing to check a fact - unless this is a deliberate detail added to hint at a major reveal (like time travel or that it is all reenactment). On the other hand, if the big reveal is that someone was a Nazi spy, this would fit right in.

Similarly, whether a story is more unconstrained soft-SF or more realistic hard-SF sets different expectations, and tells us different things about what it is about.

Soft-SF can get away with unrealistic technology and different scientific principles, for example space fighters battling as if they were WWII naval planes, but it cannot rely on too advanced real science without first explicitly establishing it first. For example, Star Wars cannot suddenly start to include relativistic time effects after those has never been shown to exist, and would need to do some serious exposition first if the story needed those.

On the other hand, the base assumption of hard-SF is that everything works as we know it, even obscure science and advanced engineering, unless explicitly shown otherwise, and its world works exactly like the one we are living in.

Now that we established that Avatar is very carefully constructed hard-SF, having even called professional scientists and engineers of varied fields in order to be the most realistic, we cannot handwave seemingly unrealistic elements as "It's just [soft-]SF". We have to try and explain it, and accept the consequences on the story.

And there are very strange elements there indeed.

Pandora and Fermi

Pandora, the world where the action takes place, is very close to the Solar System. Travel from Earth to Pandora took less than 7 years with a not-so-far-future realistic slower-than-light starship. In fact, there are at the very most a few star systems that are close enough - indeed, supplemental material tells us that it is actually the Alpha Centauri system*, literally the closest one to ours.

* The star system is Alpha Centaury, and the planetary system (the planets orbiting one star) is Alpha Centaury C. Technically the Solar System is a planetary system, but I also include such independent planetary systems into the star system definition and this article is already way too long to play with nomenclature.

For reference, our galaxy contains literally hundreds of billions of star systems - there are about fifty star systems in or galaxy alone for each living human today. And there are at least as many galaxies in the Universe, and probably much, much more.

So it seems that among this literally unimaginable amount of star systems, literally our closest neighbour also contains a planet where complex life appeared. And this life, by the miracle of convergent evolution, looks pretty much exactly like our own: green trees, flowers, dandelion seeds, canine predators...

The whole ecosystem can feel unnatural, artificial, but this may be an artefact of its uncanny chance resemblance with our own.

Barring an astronomical coincidence, this tells us that life as we know it is common, and that it converges to Earth-like forms even in relatively different atmosphere and gravity. So among those countless stars of our galaxy, we can expect at least billions of them to have an Earth-like ecosystem with reasonable certainty.
Even if a rare local event had made possible the appearance of complex life a few hundred million years ago, it would still have had to affect a large portion of the galaxy, as Alpha Centauri C was nowhere near us at that time.

There is also the question of timing: life as we know it on Earth isn't that old, compared to the age of the Universe. Our galaxy is twelve billions years, and modern-looking life is a few hundred of billions old. For about 99% of its age, Earth looked less like what we know than Pandora does. And for twice as long, there wasn't even an Earth yet in the galaxy.

There is a hypothesis that gamma rays burst were more common in the past, and that until about a few billion years ago, direct hits would have regularly destroyed complex life before it had a chance to develop. Similarly, most galaxies today may still be uninhabitable.

So right as earth is born, the galaxy becomes inhabitable and life can develop, maybe the same is true for Pandora. Both develop at a similar pace, and somehow stumble into life as we know it at about the same time.

This is stretching probabilities and hypothesis a bit, but it is plausible. Had Pandora been devoid of intelligent life, if we discovered it today, it would restrict quite a few models but not fundamentally overturn them. We would have deduced that intelligent* life is vanishingly rare, with a probably of emerging and surviving to humanity's spacefaring levels of less than one in a billion from an Earth-like ecosystem.

After all, a technological civilization like ours is very visible: radio, antimatter-powered starships, stellar engineering, Dyson spheres everywhere, galactic energy networks... Those may look out of reach today, but their science is known, and they are "merely" engineering and industrial challenges. We can expect to take a dig at those in a few hundred thousand years, an instant for cosmic time. If elder civilisations, even by a measly few million years, had emerged before us, they could have already started engineering around the entire galaxy if not beyond, including in our own Solar system. We looked for signs of those. Hard. The sky is empty.

* "intelligent" being used here as an admittedly crude shorthand for "capable of making advanced tools and developing technology"

This is how we already know today that highly visible, Human-style technological civilisation is astronomically rare at best. And this is the basis of the Fermi paradox: with such a vast and ancient Universe, why are we seemingly the only ones around?

The obvious explanation is that the probability of emergence and survival to spacefaring stages is so low that, even if in absolute numbers there may be many others in the unfathomable vastness of the Universe, the closest ones are simply in galaxies too far away for us to detect them. After all, according to what we know, even the billions of light-years of the observable Universe are at best a tiny fraction of its total size.

This implies that something, generally called a Great Filter, is severely lowering the chances of spacefarers. Some have already been ruled out: we now know that planets are common, so it cannot simply be that most star systems are empty. Pandora would rule out rareness of life at all, procaryotes, multi-cell organisms and of complex life as we know it.

And our own history rules out that civilisations simply extinguish themselves: sure, we have had setbacks and way too many close calls, but our chances to survive those and future ones, even if in the low percents, is not nearly enough to balance the astronomical odds necessary for a Great Filter - think of it that way: even if one out of a thousand makes it to the stellar engineering phase, a million civilisations should still be running around if even one star system out of a hundred let a civilisation emerge.

Unfortunately for all parties involved, as we will see in Part II, Pandora was not devoid of intelligent life, which will bring us to evoke other solutions to the Fermi Paradox...