What are some terms that desribe a single argument or idea that if true causes related larger concept false?

I'll give a silly example,....If we suddenly learned that everything we currently know about gravity is false, then this would cause all sorts of larger ideas and concepts to come crashing down. So what would the term be that descirbes what ';gravity'; would do in this particular example?What are some terms that desribe a single argument or idea that if true causes related larger concept false?
bomb shell


catalyst


pandora's box


can of worms


stunner


Double whammy


surprising turn


eye opener





I'll add more if I think of them