ट्रिविया

(at around 9 mins) Near the end of the "birds" scene, a trout is seen smashing into a window instead of a pigeon. This was a joke left in by the team that did the CG pigeons.

In the film, it is stated that the deepest hole ever dug was 7 miles deep. This is an actual fact: the shaft in question is the Kola Superdeep Borehole, a Russian project.

At the University of British Columbia, Canada, an Earth and Ocean Science course (EOSC 310) uses this film as a learning tool by showing the film to students and then analyzing the bad science behind it. Ironically, at least one of UBC's professors was consulted during the shoots that were done in Vancouver.

In demonstrating the physics of what is happening, Aaron Eckhart's character uses a peach to make his point. Unfortunately none of the peaches brought to the set were suitable so an apple was painted and had a peachstone inserted into its middle.

"Unobtainium" (sometimes spelled "Unobtanium") is a term used by science fiction fans (and some authors) for an extremely rare, not yet discovered, or physically impossible substance necessary for a given task.