“The smallest amount of fissile material needed for a sustained nuclear chain reaction.” “In social dynamics, critical mass is a sufficient number of adopters of an innovation in a social system so that the rate of adoption becomes self-sustaining and creates further growth.” - Gabriel Weinberg "A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (specifically, the nuclear fission cross-section), its density, its shape, its enrichment, its purity, its temperature, and its surroundings. The concept is important in nuclear weapon design." - Wikipedia (James Clear)
Gabriel Weinberg's Mental Models I Find Repeatedly Useful https://medium.com/@yegg/mental-models-i-find-repeatedly-useful-936f1cc405d --- James Clear Mental Models Overview https://jamesclear.com/mental-models"