Bad Physics in Movies

For physicists and physics students. See the rules before posting, and the subreddit wiki for common questions. Basic homework questions are not allowed.

physics help

**It's like Ask Science, but all questions and answers are written with answers gleaned from the universe itself.** Use in-universe knowledge, rules, and common sense to answer the questions. Or as **fanlore.org** calls it [Watsonian, not a Doylist point of view](http://fanlore.org/wiki/Watsonian_vs._Doylist)