History Main / SubspaceAnsible

Space is big. No, ''[[ScifiWritersHaveNoSenseOfScale really]]'' big. You might think it's a long way to the chemist, [[Franchise/TheHitchhikersGuideToTheGalaxy but that's peanuts compared with space. Listen]]... the only way to have snappy dialogue between characters in different star systems (hell, even to '''''the moon''''') is with faster-than-light radio. This Subspace Ansible (a.k.a. FTL Radio) is also necessary for spaceships using FasterThanLightTravel to have two-way conversations, since actual radio waves ''are'' light (of a non-visible frequency) -- and are therefore slower than the ship.

!!Aversions Without FasterThanLightTravel

* ''Series/TheTwilightZone1959'': In "[[Recap/TheTwilightZoneS5E129Probe7OverAndOut Probe 7, Over and Out]]", Colonel Cook is able to communicate with his home base 4.3 light years away in real time.

* In a typical ''TabletopGame/{{Warhammer 40000}}'' take on an otherwise innocuous trope, FTL communications within the Imperium are the responsibility of Astropaths, psykers who send telepathic messages to other planets... through ''hell''...
** And frequently, due to the RealityIsOutToLunch nature of [[HyperspaceIsAScaryPlace the Warp]], the messages either arrive too late or not at all or are completely incomprehensible due to the receiving psyker not being able to work it out via space tarot cards or throwing chicken bones or... Well, there's one example of an Imperium ship going to its death responding to a distress call sent by its future self.
** And in one case (Literature/CiaphasCain), a message announcing help was on the way was received... decades after the man leading the rescue fleet had retired and the relevant war had ended. Fortunately, Cain was the only one aware that it was an echo, and said nothing to avoid losing morale. In the end Inquisitor Vail points out that the odds of this happening at the exact time they needed it (it forced the enemy into rash actions which cost them the war) are so utterly remote that it probably counts as a miracle.

* Downplayed in ''Mecha Ace'' by Creator/ChoiceOfGames. It never gets mentioned in the main story, but if you read through the tech database it explains that ansibles are very rare and use [[QuantumMechanicsCanDoAnything quantum entanglement]] to allow instantaneous communication between planets in different solar systems.

* In ''VideoGame/MetroidPrimeHunters'', it's stated that a signal was sent to various bounty hunters via a telepathic frequency. ''VideoGame/MetroidPrime3Corruption'' introduces the Aururoa Units, partially organic super computers that form a network, allowing for instantaneous communication.

[[folder:Video Games]]
* Usually, the ''Franchise/{{Metroid}}'' games avoid this by having no form of communication through space, but in ''VideoGame/MetroidPrimeHunters'', it's stated that a signal was sent to various bounty hunters via a telepathic frequency.
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* In ''WebOriginal/OrionsArm'', messages can be sent faster than light via [[OurWormholesAreDifferent wormhole]]. One side effect of this is that some entities use systems of wormholes to cheat the normal limitations on processing speed which makes them far more powerful than they could possibly be otherwise.

*** However both China and ISS partnership claimed to have had some success changing one atom and having the other one change. China claims to have even successfully communicated with its satellite no if ands or buts. It should be mentioned that the exact details of these experiments haven't been released yet and China was more interested in using quantum entanglement communication [[MundaneUtility to make hack proof communications than FTL communications]].

** According to the [[TheWikiRule Avatar wiki]], the [[http://www.pandorapedia.com/human_operations/vehicles/isv_venture_star Pandorapedia,]] the ''Venture Star'' has faster-than-light communication technology with a low-bitrate device using quantum-entangling. This is a case of AllThereInTheManual, as this Ansible was never shown or mentioned in the film itself, though it is probably how Quaritch was able to confirm "corporate approval" for [[spoiler:Jake's legs]]. Actual faster-than-light ''travel'' is notably averted.

* In Webcomic/{{Freefall}}, it's specifically said that the only way to communicate between star systems is by sending messages via ship. As most interstellar travel is via sublight vessels (FasterThanLightTravel being quite expensive, and possibly dangerous going by the drive's name: Dangerous and Very Expensive [[[FunWithAcronyms or DAVE]]] drive), this means that a message and its response could take up to many months, as the ship carrying it travels on its normal route.

-->-- '''The Burning Bridge''' by Creator/PoulAnderson

If the setting has both subspace and hyperspace, then typically subspace will allow nearly-instant communication, but can't be used for travel. Even in ''Franchise/StarTrek'', which uses subspace for both, real-time conversations take place between characters who are days of FTLTravel apart. This allows plots to be written as if SpaceIsAnOcean. On the other hand, just as not all FTL methods are equal, neither are all FTL comms. A humble 10''c'' is technically FTL, but it'll still take about 5 months for a message to reach Earth from an Alpha Centauri colony. Raising the speed of transmission to 365''c'' turns the travel time down to 4 days, but still an eternity for any poor spacers calling for reinforcement, and God forbid you need to call for help from anywhere further. Having a determinate speed rather than [[TravelingAtTheSpeedOfPlot that of plot]] can shape a story's events. This can help mitigate UngovernableGalaxy.

[[folder:Web Comics]]

* The ''Webcomic/{{Starslip}}'' technical manual asserts that FTL communication is actually an incredibly sophisticated computer that anticipates what the other party will say. "Modern" systems are so good, it can predict and initiate a call at the same time it is placed, light-years away. FTLTravel is almost as preposterously handwaved.
** Only at first though (and hell, the strip is NAMED AFTER their FTL system), the detailed explanation becomes a major plot point and the titular Starslip Crisis when the future declares war on the past to make them stop using it.
* In ''Webcomic/AMiracleOfScience'' the Mars HiveMind developed an FTL communications network so they could be in constant contact with one another and allowed the unaugmented human colonies across the solar system to use it as well. They're capable of FTL travel as well, but they haven't told many others that yet.

* In ''WebOriginal/OrionsArm'' messages can be sent faster than light via [[OurWormholesAreDifferent wormhole]]. One side effect of this is that some entities use systems of wormholes to cheat the normal limitations on processing speed which makes them far more powerful than they could possibly be otherwise.

!!Aversions With FTLTravel

* Manga/OutlawStar seems to frequnetly make use of video messages, namely when comuncating between planets. At one point Aisha is releaved of her command and reassigned as [[ReassignedToAntarctica Reginal Officer to Blue Heaven]] by Ctarl-Ctarl Empire via video cube because of her recent blunder. She keeps trying to plead her case, but is repeatedly reminded that it is just a recording and he can't hear her. The only two way conversations seem to be when both people are on the same planet or no farther away than orbit.

* Averted in Creator/CJCherryh's ''Literature/AllianceUnion'' 'verse (including the Literature/ChanurNovels). Communications between star systems can only be done via FTL courier, and FTL travel is only possible between the outside edges of star systems. When a space ship arrives at the edge of a system and travels inwards it takes a long time for light-speed messages to reach the inner system (or vice-versa), with the time shortening as the ship hurtles forward at a considerable fraction of the speed of light.
* Creator/LRonHubbard's ''Literature/BattlefieldEarth'' features the Psychlo Empire, a civilization linked by the miracle of teleportation. Here's the thing, though - the rules of teleportation make opening two "links" to the same planet [[TeleporterAccident dangerous]], so the Psychlos set up a strict schedule of when their worlds can link up with the capital. This means that the disparate worlds of the empire have to function on their own for a year or more, until they reach the hours-long window to exchange communications and supplies and personnel. Aside from the inherent problems with this scenario, this means that once the protagonist bombs the Psychlo homeworld into a new sun, there's no way for the rest of the empire to know about this until they try to open a teleport link to it and instead get a facefull of atomic fire.

* In ''Franchise/{{Dune}}'', the Spacing Guild is responsible for getting information from place to place. In the [[Literature/PreludeToDune books by Frank Herbert's son]], Navigators and his human twin manage to contact each other FTL with a device one of them cooked up, but that never caught on, mainly due to the unfortunate side effects (namely, the navigator half died of pressure induced hemorrhaging, while the brother actually fried his brain from the inside out). It was shown that two Navigators could communicate directly mind to mind in realtime, but they also died later.
* Ditto in ''Literature/TheGapCycle'' by Stephen Donaldson. Courier drones are the order of the day -- although the Amnion do briefly try to use some sort of experimental "symbiotic crystalline resonance device" as an FTL Radio.
* In ''Literature/{{Hellspark}}'' by Creator/JanetKagan, there is FTL travel but no FTL communication. Messages have to be physically transported, and there are severe penalties for interfering with a ship carrying mail. Expeditions planning to spend time away from the regularly-travelled routes may take unmanned message drones, but these are expensive and hard to replace, and are kept in reserve for emergencies.

* In ''Literature/TheLostFleet'' series, the delay in receiving electromagnetic signals plays a large role in the various spaceship battle tactics shown. For example, at the opening of the first book, Geary uses the massive delay in communication with the enemy to buy the time he needs to rearrange the title fleet for a TacticalWithdrawal. Even then, the fleet barely makes it.

* In Peter F. Hamilton's ''Literature/NightsDawnTrilogy'', it is possible that certain alien races have developed FTL communications, but humans certainly have not. Information is couriered around by manned starships.
** In his ''Literature/CommonwealthSaga'', constantly-maintained planetside wormholes allow very rapid transportation and communications from one end of the Commonwealth to the other. The most common method of traveling from planet to planet is by ''train'', spaceships having been made redundant.
* In Creator/JohnScalzi's ''Literature/OldMansWar'' trilogy the CDF is only able to communicate between systems using courier drones. The reason for that is that FTL travel is impossible. Instead, ships actually jump to a nearly-identical (like, maybe one atom out of place) parallel universe in a new location. It's a way to cheat the normal laws of physics. Most people either don't know that or don't think about it too much.
* David Feintuch's ''Literature/SeafortSaga'': while FTL travel existed in the form of "N-Waves" propelling a ship, even human-level computer AI couldn't run a ship (robotics not being advanced in Feintuch's 'verse). Physical mail was carried by the ships traveling to extrasolar colonies, while ordinary radio was used in-system.

* In Creator/PoulAnderson's ''Literature/TechnicHistory'' novels and short stories, there is no "interstellar equivalent of radio" and all messages have to be carried by courier spaceships.
* Creator/HBeamPiper's Terro-Human Future History. News and communications travel with FTL starships -- taking months to get to their destination, and months to get an answer back -- but no FTL radio exists. This has a major impact during the System States War, in his novel ''The Cosmic Computer'', where planning and controlling fleet and army movements has to be done for a theater of war thousands of light years across. In fact, the Terran Federation's "Manhattan Project" is to create a super-powerful computer capable of evaluating not only military but social and economic factors and effectively predict the enemy's future actions, so that the Terran generals can determine just where to send troops and ships.

* 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 (called a "tightbeam" 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.]] He also uses it during ''Cetaganda'' as an excuse to act on behalf of his Imperial Security boss even though his boss has no idea what is going on, going on the logic "Well, if he ''did'' know..." -- he snarks to himself that would make a poor argument during a court martial.

* The Liir (dolphin-like aliens) from ''VideoGame/SwordOfTheStars'' use communication drones equipped with FTL engines. For gameplay reasons, there is no delay even at very long distances that require many years for the ships themselves to cross. (In game, the engines work by teleporting the object an enormous amount of times per second by small amounts, so that the ship is technically not accelerating or moving, but appears to go at up to FTL speeds.)
** The drones have a much smaller mass, meaning teleportation calculations would be much quicker (i.e. faster "movement").

[[folder:Web Comics]]
* In Webcomic/{{Freefall}}, it's specifically said that the only way to communicate between star systems is by sending messages via ship. As most interstellar travel is via sublight vessels (FTLTravel being quite expensive, and possibly dangerous going by the drive's name: Dangerous And Very Expensive [[[FunWithAcronyms or DAVE]]] drive), this means that a message and its response could take up to many months, as the ship carrying it travels on its normal route.

!!Aversions Without FTLTravel

* ''Anime/{{Planetes}}'' features a phone on a lunar colony with a Windows-esque progress bar on a video screen that gives the delay between messages between the Moon and Earth (about a second and a half)

* ''[[Anime/VoicesOfADistantStar Voices of a Distant Star]]'' subverts this by structuring the entire plot (and title of the work) around the delay in communication.

* In ''Film/{{Passengers|2016}}'' after Jim is accidentally woken up 30 years into a 120-year voyage on a SleeperStarship he sends an email to the customer service office for the company that built the ship, and then the computer says the message will take about 25 years to reach Earth and a reply should arrive in 55 years. And he just spent six thousand dollars on that one transmission.

* In the episode "All This and Gargantua-2" of ''WesternAnimation/TheVentureBrothers'', there is a "conversation" between Sgt. Hatred on Earth and Dr. Venture on an orbiting space station. Lines are weirdly repeated, and they talk over each other.

->''The message was an electronic shout, the most powerful and tightly-beamed short-wave transmission which men could generate, directed with all the precision which mathematics and engineering could offer. Nevertheless that pencil must scrawl broadly over the sky, and for a long time, merely hoping to write on its target. For when distances are measured in light-weeks, the smallest errors grow monstrous.''

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

* In a multiple shout out, the ''Series/DoctorWho'' episode "Nightmare In Silver" has a "solid-state sub-ether Ansible-class communicator".

* In ''Webcomic/DriveDaveKellet'' 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.

* [[{{Wiki/SCPFoundation}} SCP-179]] is a rare [[{{SealedGoodinaCan}} Thaumiel]]-class humanoid woman named "Sauelsuesor" located roughly 40,000 kilometers below the south pole of the sun. After a drone is sent to her location, an interview takes place via radio-waves with the log stating that the sixteen minute delay between speakers have been omitted for the sake of brevity.

* In the episode "All This and Gargantua-2" of ''WesternAnimation/TheVentureBrothers'', there is a "conversation" between Sgt. Hatred on Earth and Dr. Venture on an orbiting space station. In a subversion of ContinuityEditing, lines are weirdly repeated, and they talk over each other.

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** 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]]. The Black Boxes have two major disadvantages compared to standard [=HPGs=]: first, their transmissions are not instantaneous so there's a delay based on how far the broadcasting Black Box is from the receiving one. Second, they don't have the ability to send transmissions only to selected receivers- they simply broadcast in every direction and all Boxes within range will get the signal, making them useless as a means of secure communication as soon as more than one faction has them.

* ''Fanfic/{{Frontier}}'' has The [=HoloNet=], par for the course in a work featuring the technology of ''Franchise/StarWars''. ''Mass Effect'' has its quantum entanglement devices, and ''Borderlands'' has a "relay" network.