History Main / SubSpaceAnsible

** The novelization to ''Film/AlienThree'' says sending a message back to Earth costs.more than the average person makes in a lifetime.

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* The ''Literature/GreatShip'' universe, being MundaneDogmatic, lacks either FTL travel or communications. The scientists that seized control of the derelict [[PlanetSpaceship Greatship]] routinely beam messages back to Earth via communication lasers which will take over a thousand years to be received. The huge communication delays are generally no more than an annoyance because, hey, you're TransHuman and [[TimeAbyss are gonna outlive civilizations]]. It does however become a plot point at the climax of ''The Well of Stars'', where [[spoiler: the Greatship is seized by {{Starfish Alien}}s and its true reactionless engines are activated; it'll take a human fleet thousands of years to catch up with the Greatship as it flies into intergalactic space]].

** In some circumstances, long-range communications occur in realtime, and in others they do not. Some ExpandedUniverse sources indicate that the signals can be effectively instantaneous if the signal strength is high enough, but this requires a repeater network to maintain over more than a few tens of lightyears. The ''[[AllThereInTheManual TNG Technical Manual]]'', meanwhile, explains that Starfleet exploratory vessels automatically drop subspace signal boosters as they travel in order to maintain contact with the Federation.

* ''Franchise/StarWars'', of course. The galaxy-spanning [=HoloNet=] allows people to communicate in real time through holograms despite being separated by thousands of light years. Suitable communications systems on ships connect via relay stations spread throughout the galaxy in a manner similar to the real world cellular network. Users accessing the [=HoloNet=] can also be located via the network, as shown in ''Film/ThePhantomMenace'' and ''Film/AttackOfTheClones''. "Disturbances in TheForce" can also be sensed instantaneously, even if the source is in real space and the Force-sensitive is in hyperspace, as when Obi-Wan sensed the destruction of Alderaan. The case of Darth Vader manipulating Luke to convince him to visit Bespin actually exploited visions of the future rather than this, Luke saw those happening before Han and Leia even arrived.

* This is the cause of the central conflict in [[Literature/TheThreeBodyProblem]] and its sequels. The lack of Faster than Light communication over interstellar distances means that alien species cannot effectively build trust with each other and can only exterminate rival species before they are exterminated themselves.

* ''Anime/Interstella5555'': In the final scene, people on Earth (including one guy on the International Space Station) are shown watching a live concert from The Crescendolls' homeworld.

* ''VideoGame/AxiomVerge2'' has several ansibles resembling old computers that are capable of communicating with each other instantaneously, even between worlds (such as between Earth and Kiengir, or even [[spoiler:the afterlife]]). However, the computers are an early model with ''very'' low, hard-coded memory limits -- as such, Indra's communication with Dr. Hammond ends up being two or three sentences per ansible until near the end of the game, at which point one of them receives an upgrade.

** The reason why quantum entanglement cannot be used for FTL communication is this: imagine you have two entangled particles. Particle A is with you and Particle B is many light-years away. Obviously, you can easily measure Particle A to find out something about its state (say, its spin). Once you know the spin of A, the spin of B is determined and anyone measuring the spin of B will definitely measure the opposite of what you measured. To use this for communication, you would have to somehow "force" particle A to take on a certain spin. But, this is fundamentally impossible as any interference will collapse the particle's wavefunction, breaking the entanglement.

* ''VideoGame/AxiomVerge2'' has several ansibles that are capable of communicating with each other instantaneously, even between worlds (such as between Earth and Kiengir, or even [[spoiler:the afterlife]]). However, the ansibles seen in-game are an early model with ''very'' low, hard-coded memory limits -- as such, Indra's communication with Dr. Hammond ends up being two or three sentences per ansible until near the end of the game, at which point one of them receives an upgrade.

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* ''Radio/JourneyIntoSpace'': {{Averted|Trope}}. This becomes a plot point in ''The Red Planet'', when [[spoiler: the lack of any significant delay in communicating with Earth alerts the ''Discovery'' crew to the fact that the voice is an impostor, that of James Edward Whitaker]].
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* In ''Webcomic/{{Drive}}'' most interstellar messages are carried by ships, but there's a recently developed network of relay stations that use the ring drive's space-folding to enable real-time communication [[http://www.drivecomic.com/archive/150123.html across the galaxy]]. However it's expensive enough that it's usually used by the Imperial Familia on-screen.

* In ''Series/AlteredCarbon'', this technology is implied to have been developed, as ''[[MentalSpaceTravel Needlecasting]]'' is shown to be near instantaneous.

* In ''Series/AlteredCarbon'', this technology is implied to have been developed, as ''[[MentalSpaceTravel Needlecasting'' is shown to be near instantaneous.

* The characters in ''WebOriginal/{{17776}}'' communicate with each other in real-time by establishing a "[[QuantumMechanicsCanDoAnything quantum link]]", which can apparently be installed on any old space probe. Regular satellite communication would take about 217 days to transmit.

* Curious version in Creator/JamesBlish's short story "Beep" (later expanded into the novel ''The Quincunx of Time''). Ansibles are common and cheap to use, if you can stand the loud and annoying beep that accompanies every one. Due to quantum effects, the title beep contain every message that ever was or will be sent, ever, and they can be heard if slowed way, way down and appropriately filtered. The government's primary purpose is to ensure that the events described in the beep come to pass at all costs, to prevent a paradox from prematurely ending the universe.

* Galaxy Network in ''Anime/StarshipOperators'' is suggested to use quantum entanglement in dialogue.

* Creator/LoisMcMasterBujold's ''Literature/VorkosiganSaga'' uses wormholes as shortcuts through space; unfortunately, there's no way to send messages through a wormhole without recording them and putting them on a ship. High traffic routes have regular courier ships shuttling the mail back and forth through the wormholes. On low traffic routes, your mail may sit for weeks for someone to come along and carry it on. Once on the other side, a message may be beamed at the speed of light to the next wormhole (if there's a permanent station there) or it may be carried on a ship the whole way.
** The lack of FTL communication plays as a plot point a few times; in ''Literature/TheVorGame'', Miles uses the time lag between communications to [[MindScrew play with the head]] of his compulsive plotter opponent, [[spoiler: Cavilo.]]

* In ''VideoGame/FTLFasterThanLight'', your ship is carrying a message to TheFederation, delivering it in person rather than by any signal. It is implied that transmissions cannot go faster than light, but [[ExactlyWhatItSaysOnTheTin you can]].

* Similarly, the ''VideoGame/WingCommander'' series explicitly uses FTL radio with no particular explanation given for the differences between how it and jump drives work.

** A secret technology developed by the Star League before [=HPGs=] but abandoned when [=HPGs=] were more practical was the "Black Box" devices. Instead of point-to-point, the Black Boxes worked instead by broadcasting much like a radio, but into hyperspace. The Federated Commonwealth acquired and developed the technology to secretly break the monopoly on interstellar communication via [=HPGs=] by the "officially politically neutral" quasi-religious organization known as [[NGOSuperpower ComStar]].

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