But well, at least the Cat People have the justification of being able to defy the laws of biology, since they have blue pigments even though Alpha Centauri seems to emit light of the same spectrum as the Sun, have two eyes even though all other shown vertebrates have four and live in an environment where predators evolved the ability to get hijacked by their prey.

I find it ridiculous that they were using manned gunship and manned mechs. The neck radios they wore and the avatar mind link communication worked flawlessly despite the vortex so why would they compromise the performance of their machines by including space for people and risk those peoples lives when it could all be controlled back at base, wont UAVs be advanced by then?

The most stupid thing is all the exposed gunners everywhere .Behind the door on the little helicopters and all over the top of the big one. They cant control those guns remotely behind a screen like we are starting to do today? They have to have exposed people?They hae amazing 3d displays.

Why would the aliens use wood arrows when they could use those carbon fiber animal bones? The humans can make an avatar hybrid but not an antidote for the neurotoxin?

Lastly What kind of muscle energy would it take for a predator to kill an animal with thick but light carbon fiber armor? I’ll leave that one to you also.

Oh and apparently it has five-fold crystal symmetry which I thought was impossible..?

Of course, Cameron himself has said that the floating mountains came from an image that came out of a dream he had (this interview, in the question starting around 19:00), rather than any basis in hard science, and they are a beautiful image in that regard!

That explains strong fields near the surface, which could then contribute to the levitation of the mountains of unobtainium by field pinning. But that still doesn’t explain how the metallic military technology can operate in the region — or how organisms can move around without being affected by the diamagnetism of water.

YorgZ’s proposal of a (hitherto-unknown in nature) magnetic amplification effect in the Pandora rocks seems the simplest way to make it all add up. Crucially, the amplification effect needs to occur only in the core of the rock arch/mountain, otherwise organisms on the surface would experience the high magnetic fields. So something like superparamagnetism wouldn’t work unless you could explain the shielding of the magnetic force outside of the ring arch/floating mountain.

There’s a concept in planetary studies called the “Roche Limit.” That is the orbital radius at which, if a moon is any closer in to the planet it orbits, tidal forces from the planet will rip apart the moon into little chunks, turning it into rings like Saturn’s. Outside that limit, tidal forces from the planet may deform the moon (just like tides from Earth’s Moon deform the shape of our oceans), but the moon’s self-gravity is enough to hold it together. So, if Pandora’s floating mountains were a result of the gravitational pull from Polyphemus, that would be a sign that Pandora is dangerously close to the gas giant’s Roche Limit and is starting to get ripped apart! If Pandora was at that point, I’d expect the Na’vi climbing up the Hallejuah Mountains to also drift up from Pandora’s surface if they let go of their hold on the mountain!

There’s also the issue of where on Pandora the mountains are. I’m not sure if Pandora is tidally locked to Polyphemus (with one side of the moon always facing the planet – like our Moon), but if it’s not, then the site(s) with the mountains would see Polyphemus rise and set again and again. THAT might have a distinct gravitational effect on the mountains, as gravity would periodically push and pull on the floating mountains. It might get the mountains slowly oscillating, or might destabilize them and cause them to crash into each other or Pandora’s surface.