Definition
Information-as-surprise — Shannon entropy received as cosmic-ordinance. Named from Shannon's 1948 measure H = -Σ p·log p + Sumerian me (received-ordinance). The information a message carries is its surprise: a message fully expected carries nothing, and the rarest outcome carries the most. The source-side measure of the information cluster: how much news a source can carry at all. The founding quantity of the information age.