Invisible College

The Invisible College was the name given to themselves by a group of like-minded scientists and natural philosophers in England in the mid-17th century. The informal association is considered to have been one of the origins of the Royal Society.
The purpose of the invisible college was to encourage each other to develop scientific knowledge through experiments and other kinds of investigation.
Some of the members of the Invisible College were among the founders of the Royal Society in 1660, including Robert Boyle, John Wilkins and Samuel Hartlib.
Modern use.
The concept of invisible college was developed in the sociology of science by Diane Crane, building on de Solla Price's work on citation networks. It is related to, but significantly different from, other concepts of expert communities, such as "Epistemic communities", or "Communities of Practice". Recently, the concept was applied to the global network of communications among scientists by Caroline S. Wagner.
In fiction it is mentioned in the novel "The Lost Symbol" by Dan Brown, and was the inspiration for the Unseen University in the works of Terry Pratchett.