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

Question

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?

Answer 1

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