How to Mess Up Archeology
The Movie: Shaw and Holloway discover a preserved alien head. After carbon dating it, they run away with it, drop it, and finally blast it apart with electricity.
Real Life: Archeologists must have had a conniption fit watching this movie. On a real dig, everything is labelled, catalogued, and photographed multiple times before it is excavated (if indeed it's removed at all). The position and surroundings of artifacts tell us a lot about them, so just picking them up and running with them is, ya know, not standard practice. Exploding them for no reason is especially frowned upon. Also, carbon dating wouldn't work on an alien world because we'd have no idea how much carbon-14 is in the atmosphere, and so they would have nothing against which to measure the decay of the isotope. Nice try, dummies.