Observer

Observer may refer to:

• Any person who is observing
• The Observer personality type
• Air observer, an aircrew member of a (usually military) aircraft
• Observer (special relativity), a notion from the special relativity theory
• In information theory, any system which receives information from an object.
• A state observer in control theory, a system that models a real system in order to provide an estimate of its internal state
• Observer pattern, a design pattern used in computer programming
• Observer (MST3K) aka Brain Guy, one of many omnipotent aliens in Mystery Science Theater 3000
• "The Observer", a track from The Flaming Lips' 1999 album The Soft Bulletin
• The observer effect, changes that the act of observing will make on the phenomenon being observed
• "Observer Effect", the 87th episode from the television series Star Trek: Enterprise

Publications

• The Observer, a UK Sunday newspaper
• The Texas Observer, an American political magazine
• A Sri Lankan Sunday and evening newspaper
• The Observer (disambiguation), various newspapers