Common knowledge

Common knowledge is knowledge that is publicly known by everyone or nearly everyone, usually with reference to the community in which the knowledge is referenced. Common knowledge can be about a broad range of subjects, such as science, literature, history, or entertainment. Since individuals often have different knowledge bases, common knowledge can vary and may sometimes take large-scale studies to know for certain what is common knowledge amongst large groups of people. Often, common knowledge does not need to be cited. Common knowledge is distinct from general knowledge. In broader terms, common knowledge is used to refer to information that an agent would accept as valid, such as information that multiple users may know. Assigning something the label of common knowledge requires certain considerations about the involved community, group, society and/or individuals, the time period, and the location. Defining something as common knowledge can differ based on circumstances because there are variations in what is considered common knowledge amongst different groups. The variation can come from the time period, culture, population, class, age, demographic, and other circumstances. For example, The Fifth Amendment to the United States Constitution might be considered common knowledge among people residing in the United States of a certain age, but cannot be considered common knowledge when considering the general population of other countries. Common knowledge is not always stable, and can shift over time to create new common knowledge. Knowledge that was once considered common knowledge amongst a group, society, or community might later become known as false. For example, for centuries it was common knowledge in Europe that the Sun revolved around the Earth, but after years of arguments, it is now common knowledge that the Earth revolves around the Sun. On a larger global scale, it is not possible to define almost any knowledge as common knowledge because it is difficult know how far a fact has spread in global populations without large-scale global population studies.