FTL Radio
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Basic Information

An FTL Radio (also sometimes known as an Ansible or Subspace Ansible) is a communication device popular in science fiction that makes it possible to communicate across vast distances, such as the void between stars, in a reasonable and normal manner. It's pretty much a strict violation of Relativity. Some settings that otherwise obey the laws of physics, and thus don't have FTL Stardrive, will often have an FTL Radio for plot or style reasons.

In some settings, FTL radio is accomplished by beaming normal radio waves through Hyperspace or Subspace or via a Worm Hole. In other settings, FTL radio uses Ultrawaves or Hyperwaves. Rarely does science fiction devote much time or energy to explain how such things work. If using Ultrawaves, it would make sense for the setting to also use such super-radio-waves as FTL sensors to detect space ships moving near, at, or beyond the speed of light before they arrive.

Unlike a Tachyonic Antitelephone, the FTL radio doesn't play little games with time. Instead, it ignores all that Einsteinian logic about FTL being Time Travel, and just functions like radio does in our mundane world. In fact, the whole point of FTL Radio is basically to allow communication via a method that the viewer (or gamer) is familar with. The science of the Ansible is generally ignored, or hand waved as involving Hyperspace or Subspace.

The term "Ansible" was coined by Ursula K. Le Guin in her novel Rocannon's World. It's since been borrowed by other authors. The word Ansible is a variation on "Answerable", alluding to the idea that a FTL Communication would make it possible to hold a conversation or answer a distress call in normal time. Without such a device, it might be years before anyone even gets your deep space distress call. Talking to another planet in the solar system would have long pauses equating to the several minutes of delay it takes for light or radio waves to travel that distance. The Ansible renders it as normal as earthbound radio or cellphone conversation.

Old School science fiction will sometimes use the term "sub-ether", referring to the old idea of Lumineferous Aether. Some of Isaac Asimov's stories refer to "the Sub-etherics" as an entertainment medium like radio or television.

See Also:



Game and Story Use

  • Probably the easiest way to depict interplanetary communication within a Space Opera or other sci-fi game, as there's no physics to figure out, and no metaphysical baggage like there would be if you went the psychic route.
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