Corrected entry: The science of Pandora is all wrong. For example, they have regular days and nights there, but Pandora is not a planet, circling a sun, it's a moon, circling a planet. The days and nights would coincide with the rotation around the planet. For an extended period, when the planet was between Pandora and the sun, it would be dark, probably weeks at a time, and the opposite for daylight hours. In addition, because Pandora is a satellite of a gas giant, that means its orbit would be millions of miles in variance. There would be a few weeks of winter as it came several million miles further from the sun in its orbit, and then it would be several weeks of blistering summer as it came closer. The vegetation and ecology of the movie are treating the moon as if it had the same cycles and system as a planet, which is impossible. Even it took Pandora a year or more to orbit its planet, so that seasons were more regular, that means it would be in darkness for months as the planet was between it and the sun. If it rotated in a month, that means that it would be going through all 4 seasons 12 times a year, or however many months there were to a Pandoran year.
Corrected entry: When Jake is transformed at the end, he has no mask, so he couldn't have been breathing for the transformation.
Corrected entry: In the scene we see Pandora's sky, in the sky we see a gigantic planet and another planet (or kind of a moon) but much smaller (like our moon). In this shot we see a shadow on the big planet (on its right side) which looks like it caused due to the small moon shadowing it, but when looking on the small moon we see that its left half is black (no sun) and right half is white (sun on it). This means that the sun is on the right side of the picture outside the frame. If that is the case there is no way that this moon (or even Pandora itself) will create a shadow on the big planet.
Corrected entry: Why don't the avatars have a GPS chip implanted in them while they are being "grown" on the trip from Earth? They lost Jake when he got separated from the group and the Marines couldn't locate him when they were fighting. You would think that the avatars cost millions if not billions to make -- and they couldn't put a $30 GPS chip in their neck?
Corrected entry: There's no oxygen on Pandora, yet Jake is able to light a fire when he's in the forest. You need oxygen in order to make fire.
Corrected entry: Bicycle or motorcycle, when cornering, a person leans into the corner, centrifugal force pushing them into the seat. In the flight scenes, every banking turn the characters stay upright, but magically have no problem staying seated, highlighting the lack of centrifugal force.
Corrected entry: When Hometree is felled, it is seen that it takes several seconds for it to fall a small distance as Tsu'tey and the other Na'vi escape with the ikran. However, in the shot of all of Hometree, it falls much more quickly.
Corrected entry: To speak to each other when they are out of the range of hearing each other, they have communication devices around their necks and they press it when they want to talk. But quite a few times sometimes they use it and sometimes they don't, eg, when Jake goes out with Sigourney in the helicopter, as Avatars, Jake wanders off and Sigourney speaks to him through the communications device, but later, when they are the same distance apart, she just talks to him normally.
Corrected entry: Neytiri's mother, Mo'at, has three arms. As Neytiri runs towards Mo'at, Mo'at holds out her arms to hold her. She puts one around her waist, the other around her arm. But then her arm splits so that she now has two arms on her daughter's left arm, one arm on her daughter's waist.
Corrected entry: All throughout the movie humans are dying because they can't breathe on the planet. But then at the end of the movie all the humans are being ushered out without any masks or anything (specifically, when Parker looks at the camera you can clearly see he is not wearing a mask) and are breathing fine?
Corrected entry: During the big bombing of the tree, Michelle Rodriguez refuses to take part and steers the helicopter away, stating that she does not want to be part of that. Even in the distant future, such behaviour would be called insubordination and have her court-martialed. However, she is still able to free Jake and has access to the helicopters in the hangar.
Corrected entry: Grace incorrectly relates Jake's escape to the others: The last thing we see is this Marine's ass disappearing into the brush with this angry thanator coming after him. That was not a thanator; that was a different type of creature altogether. The thanators were the hammerhead-rhino creatures, but the one that chased Jake was a very different sleek black creature.
Corrected entry: The great expense of the avatar program is mentioned early in the film, hence wanting to use Jake so as not to waste his brother's avatar. Why then, since Jake has them over a barrel so to speak, doesn't Jake ask the corporation to repair his spine as a condition for joining the program? The Commander promised to get them for him if he spied on the Navi. It just seems that he could have avoided the whole spy/betrayal dilemma.
Corrected entry: At the end of the big battle, the survivors are lined up and are leaving Pandora but to where? All the ships from earth will be full and it will take at least 5+ years for empty ships to arrive to evacuate the survivors.