A copernican trauma is a deeply disturbing event - an event or discovery - that completely upsets or changes our way of thinking. We become traumatised or deeply upset because what we deeply believed in the past is now no longer true. Example: We have always had a deep, almost religious belief about something, and then suddenly something happens: a discovery, a proof. This discovery upsets/traumatises us because now we have to accept a new belief. The term comes from "Copernicus" who discovered that we are not the centre of the universe, but the Earth revolves around the sun. A traumatic event for many who thought the Earth was the centre of the universe.