Kim Stanley Robinson used this in several books, calling it a “pebble mob”. Picture an explosion run in reverse time, with the fragments converging at a point. Or a hundred drones, as in this interview with him.
https://bioneers.org/kim-stanley-robinson-on-his-book-the-ministry-for-the-future/
I’ve come to define a belief as a self-reinforcing opinion. That leaves open how it is reinforced, e.g. by testing against reality in the case of a prediction, or by confirmation bias in the case of a delusion.