Critical mass (sociodynamics) is like when people get together and form a group and make something happen. To explain it in the simplest way, think of it like a group of kids wanting to ride a roller coaster. If there aren’t enough kids, the roller coaster won’t go. But, if enough people come together and get in line, the ride will happen and become fun for everyone. In sociodynamics, critical mass is when a large enough group of people come together, work together and get something done. They become powerful enough to make a change in society.