babelfish

The Babel fish is a fictional species of fish in The Hitchhiker's Guide to the Galaxy by Douglas Adams, where it is described thus:

The Babel fish is small, yellow and leechlike, and probably the oddest thing in the Universe. It feeds on brainwave energy received not from its own carrier but from those around it. It absorbs all unconscious mental frequencies from this brainwave energy to nourish itself with. It then excretes into the mind of its carrier a telepathic matrix formed by combining the conscious thought frequencies with nerve signals picked up from the speech centres of the brain which has supplied them. The practical upshot of all this is that if you stick a Babel fish in your ear you can instantly understand anything said to you in any form of language. The speech patterns you actually hear decode the brainwave matrix which has been fed into your mind by your Babel fish.

The Babel fish was a useful plot device for Adams, as it allowed various alien races to communicate while speaking different languages. Adams wrote that the idea that all aliens would speak English was, to him, very strange.

It was revealed in the Quintessential Phase that it also, like dolphins, has the power to effectively teleport itself and its host (in a plural zone) out of fatal danger.

The fish's name refers to the Tower of Babel, a Biblical story, which describes events in Abrahamic theology which led to God confusing the languages of Man in order to prevent the Tower's construction, among other things.

Existence of God

The Babel fish also triggered a joke about the existence of God, since the Babel fish was put forth as a fideist example for the non-existence of a deity:

"I refuse to prove that I exist," says God, "for proof denies faith, and without faith I am nothing."

"But," says Man, "the Babel fish is a dead giveaway isn't it? It could not have evolved by chance. It proves that you exist, and so therefore, by your own arguments, you don't. Q.E.D."

"Oh dear," says God, "I hadn't thought of that," and promptly vanishes in a puff of logic.

"Oh, that was easy," says Man, and for an encore goes on to prove that black is white and gets himself killed on the next zebra crossing.

In the feature film The Hitchhiker's Guide to the Galaxy, that scene was omitted and placed under "Deleted Scenes".

Web site

In a demonstration of the appeal that Hitchhiker's Guide has in the technology community, Babel Fish was the name used by one of the earliest translation sites on the World Wide Web.