Computer science and information theory

• In information theory
  Information theory
  Information theory is a branch of applied mathematics and electrical engineering involving the quantification of information. Information theory was developed by Claude E. Shannon to find fundamental limits on signal processing operations such as compressing data and on reliably storing and...
  
  , any system which receives information from an object.
• A state observer
  State observer
  In control theory, a state observer is a system that models a real system in order to provide an estimate of its internal state, given measurements of the input and output of the real system. It is typically a computer-implemented mathematical model....
  
   in control theory, a system that models a real system in order to provide an estimate of its internal state
• Observer pattern
  Observer pattern
  The observer pattern is a software design pattern in which an object, called the subject, maintains a list of its dependents, called observers, and notifies them automatically of any state changes, usually by calling one of their methods...
  
  , a design pattern used in computer programming
• ObserverNMS (software), a network management software package

Fiction

• Observer (Mystery Science Theater 3000), aka Brain Guy
• Observers, non-linear beings in the television show Fringe

Music

• "Observer", a song by Gary Numan
  Gary Numan
  Gary Numan is an English singer, composer, and musician, most widely known for his chart-topping 1979 hits "Are 'Friends' Electric?" and "Cars". His signature sound consisted of heavy synthesizer hooks fed through guitar effects pedals.Numan is considered a pioneer of commercial electronic music...
  
   on his album The Pleasure Principle
  The Pleasure Principle (Gary Numan album)
  The Pleasure Principle is the third studio album, and debut album under his own name, by electronic music pioneer Gary Numan, released in 1979...
  
  
• "The Observer", a track from The Flaming Lips
  The Flaming Lips
  The Flaming Lips are an American alternative rock band, formed in Oklahoma City, Oklahoma in 1983.Melodically, their sound contains lush, multi-layered, psychedelic rock arrangements, but lyrically their compositions show elements of space rock, including unusual song and album titles—such as "What...
  
  ' 1999 album The Soft Bulletin
  The Soft Bulletin
  -UK & Australian CD release:-Vinyl release:-The Soft Bulletin 5.1:On January 31, 2006, Warner Bros. re-released The Soft Bulletin in the US as a two-disc package titled The Soft Bulletin 5.1. It includes a remastered CD and a DVD-Audio disc that contains a 5.1-channel surround sound mix of the album...
  
  

Physics

• Observer (physics)
  Observer (physics)
  The term observer has a number of non-equivalent uses in science.-Special relativity:The term observer in special relativity refers most commonly to an inertial reference frame....
  
  
• Observer (special relativity)
  Observer (special relativity)
  The term observer in special relativity refers most commonly to an inertial reference frame. Less often it may refer to an arbitrary non-inertial reference frame; in particular, a Rindler frame is sometimes called an "accelerating observer". In such cases an inertial reference frame may be called...
  
  , a notion from the special relativity theory
• Observer (general relativity)
• Observer (quantum physics)
  Observer (quantum physics)
  In quantum mechanics, "observation" is synonymous with quantum measurement and "observer" with a measurement apparatus and observable with what can be measured. Thus the quantum mechanical observer does not...
  
  

Politics and diplomacy

• Observer status
  Observer status
  Observer status is a privilege granted by some organizations to non-members to give them an ability to participate in the organization's activities. Observer status is often granted by intergovernmental organizations to non-member states and international nongovernmental organizations that have...
  
  , granted by an organization to a non-member, allowing the non-member limited ability to participate in the organization's activities
• An election observer, one who assists in election monitoring
  Election monitoring
  Election monitoring is the observation of an election by one or more independent parties, typically from another country or a non-governmental organization , primarily to assess the conduct of an election process on the basis of national legislation and international standards. There are national...
  
  

Publications

• The Observer
  The Observer
  The Observer is a British newspaper, published on Sundays. In the same place on the political spectrum as its daily sister paper The Guardian, which acquired it in 1993, it takes a liberal or social democratic line on most issues. It is the world's oldest Sunday newspaper.-Origins:The first issue,...
  
  , a UK Sunday newspaper
• The Texas Observer
  The Texas Observer
  The Texas Observer is an American political newsmagazine published bi-weekly and based in Downtown Austin, Texas. The non-profit magazine is nonpartisan, but the publication has historically been an advocate for liberal politics...
  
  , an American political magazine
• A Sri Lankan Sunday and evening newspaper
• The Observer (disambiguation)
  The Observer (disambiguation)
  -Periodicals:Australia*The Observer , daily newspaper in Gladstone, Queensland*The Observer , fortnightly magazine founded in 1958, absorbed by The Bulletin in 1961Gambia*The Daily ObserverJamaica...
  
  , various newspapers

Other

• A game official used in some competitions of Ultimate
  Ultimate (sport)
  Ultimate is a sport played with a 175 gram flying disc. The object of the game is to score points by passing the disc to a player in the opposing end zone, similar to an end zone in American football or rugby...
  
  
• The Observer personality type
• Air observer
  Air observer
  An air observer is a British term for a military aircrew member whose duties are predominantly reconnaissance. The term originates in the First World War in the Royal Flying Corps, and was maintained by its successor, the Royal Air Force...
  
  , an aircrew member of a (usually military) aircraft