We finally have an answer: The beginning and the end of the sliding motion that produces static electricity experience different forces – resulting in a charge differential between the front and the back that results in the crackle of static electricity.
Maybe you just went to bad schools?
My experience with science and other teachers of every grade was that they stressed how we make new discoveries all the time.
Maybe I went to bad schools, maybe my country has a dysfunctional education system, but I suspect the matter is widespread because it’s way easier to teach factual information rather than dive into the nuances of how confident we are about our explanations.
Some reductive examples: Pluto is / is not a planet, wings work because the path air takes is longer than on the other side, the cause for this war was xyz, you can’t subtract below 0 (that’s at a very early age of course), this philosopher thought X.
Oh I guess a CRUCIAL one is how most teachers are horribly unfit to answer “Why should I care about this?”, but that’s beside the point, in a way.