Character mistake: In the beginning scene where the shuttle lands on Pandora, as Jake gets on his wheelchair preparing to alight from the shuttle, the man behind him unloading equipment has his exopack mask loose even though he is exposed to Pandora's atmosphere. (00:05:20)
Character mistake: Grace is doing something 'scientific' in the background while Jake is submitting his video report. She holds a filled pipette upside down, which caused some mirth with the biologists watching the movie with me. The pipette is always held with the opening downwards, because if you turn it upside-down, liquid may flow into the pipette mechanism and contaminate it, or become contaminated. Grace however turned the pipette with opening upwards, which is not what a professional scientist would do.
Chosen answer: The Core didn't originate the name - it's been used since the 50's and even has its own Wikipedia article at http://en.wikipedia.org/wiki/Unobtainium. There it's described as "any fictional, extremely rare, costly, or impossible material, or (less commonly) device needed to fulfill a given design for a given application."
Jon Sandys ★