Ansible
Ansible
An ansible is a hypothetical machine capable of instantaneous or superluminal communication. Ansibles are used as plot devices in science fiction literature.
Contents
* 1 Origin
* 2 Usage
o 2.1 In Le Guin’s work
o 2.2 In Card’s work
o 2.3 In reality
* 3 See also
* 4 References
* 5 External links
Origin
The word ansible was coined by Ursula K. Le Guin in her 1966 novel, Rocannon’s World.[1] Le Guin states that she derived the name from “answerable,” as the device would allow its users to receive answers to their messages in a reasonable amount of time, even over interstellar distances.[citation needed] Her award-winning 1974 novel The Dispossessed[2] tells of the invention of the ansible within her Hainish Cycle.
Usage
The name of the device has since been borrowed by authors such as Orson Scott Card,[3] Vernor Vinge,[4] Elizabeth Moon,[5] Jason Jones,[6] L.A. Graf,[7] and Dan Simmons.[8] Similarly functioning devices are present in the works of numerous others, such as Frank Herbert[9] and Philip Pullman, who called it a lodestone resonator.[10]
Anne McCaffery’s Crystal Singer series posited an instantaneous communication device powered by rare ‘Black Crystal’ from the planet Ballybran. Black Crystals cut from the same mineral deposit could be “tuned” to sympathetically vibrate with each other instantly, even when separated by interstellar distances, allowing instantaneous telephone-like voice and data communication.
Stephen R. Donaldson, in his Gap Series, proposed a similar system, Symbiotic Crystalline Resonance Transmission, clearly ansible-type technology, but was very difficult to produce and limited to text messages.
Some hard science fiction stories use small (possibly nano sized) paired wormholes dedicated to communication via a laser which traverses the wormhole.[citation needed]
One ansible-like device which predates Le Guin’s usage is the Dirac communicator in James Blish’s 1954 short story “Beep”. As the title implies, any active device received the sum of all transmitted messages in universal space-time, in a single pulse, so that demultiplexing yielded information about the past, present, and future.
Isaac Asimov solved the same communication problem with the hyper-wave relay in The Foundation Series.
Le Guin’s ansible was said to communicate “instantaneously”,[2] but other authors have adopted the name for devices explicitly only capable of finite-speed communication (though still faster than light).
The subspace radio, best known today from Star Trek and named for the series’ method of achieving faster-than-light travel, was the most commonly used name for such a faster-than-light (FTL) communicator in the science fiction of the 1930s to the 1950s.[citation needed]
In Le Guin’s work
In The Word for World Is Forest, Le Guin explains that in order for communication to work with any pair of ansibles, at least one “must be on a large-mass body, the other can be anywhere in the cosmos.”
In The Left Hand of Darkness, the ansible “doesn’t involve radio waves, or any form of energy. The principle it works on, the constant of simultaneity, is analogous in some ways to gravity… One point has to be fixed, on a planet of certain mass, but the other end is portable.”
Unlike McCaffrey’s black crystal transceivers, Le Guin’s ansibles are not mated pairs as it is possible for an ansible’s coordinates to be set to any known location of a receiving ansible. Moreover, the ansibles Le Guin uses in her stories apparently have a very limited bandwidth which only allows for at most a few hundred characters of text to be communicated in any transaction of a dialog session. Instead of a microphone and speaker, Le Guin’s ansibles are attached to a keyboard and small display to perform text messaging.
In Card’s work
See also: Concepts in the Ender’s Game series
Orson Scott Card’s Ender’s Game series uses the ansible as a plot device. (“The official name is Philotic Parallax Instantaneous Communicator,” explains Colonel Graff in Ender’s Game, “but somebody dredged the name ansible out of an old book somewhere”).[3]
His description of ansible functions in Xenocide involve a fictional subatomic particle, the philote, and contradicts not only standard physical theory but the results of empirical particle accelerator experiments.
In the “Enderverse”, the two quarks inside a pi meson can be separated by an arbitrary distance while remaining connected by “philotic rays”. This is similar in concept to quantum teleportation due to entanglement, although even that is not capable of faster-than-light communication. Also, in the real world, quark confinement prevents one from separating quarks by more than microscopic distances.
In reality
There is no known way to build an ansible. The theory of special relativity predicts that any such device would allow communication from the future to the past, which raises problems of causality. For this reason, most physicists believe that they will eventually be proven impossible.
The quantum non-local connection is often proposed as a mechanism for superluminal communication[10] (a 2008 quantum physics experiment performed in Geneva, Switzerland has determined that the “speed” of the quantum non-local connection has a minimum lower bound of 10,000 times the speed of light[11]). Practical applications are disputed due to the no cloning theorem, although, the no cloning theorem does not prevent superluminal communication via quantum entanglement, as cloning is a sufficient condition for such communication, but not a necessary one.
Nevertheless, consider the EPR thought experiment, and suppose quantum states could be cloned. Assume parts of a maximally entangled Bell state are distributed to Alice and Bob. Alice could send bits to Bob in the following way: If Alice wishes to transmit a “0″, she measures the spin of her electron in the z direction, collapsing Bob’s state to either |z+\rangle_B or |z-\rangle_B. To transmit “1″, Alice does nothing to her qubit. Bob creates many copies of his electron’s state, and measures the spin of each copy in the z direction. Bob will know that Alice has transmitted a “0″ if all his measurements will produce the same result; otherwise, his measurements will have outcomes +1/2 and −1/2 with equal probability. This would allow Alice and Bob to communicate across space-like separations.
See time travel and faster-than-light for more discussion of these issues.
See also
* Faster-than-light
* No cloning theorem
* Tachyon
* Interstellar communication
References
1. ^ Quinion, Michael. “Ansible”. World Wide Words. http://www.worldwidewords.org/weirdwords/ww-ans1.htm.
2. ^ a b Le Guin, Ursula K. (August 2001) [1974]. The Dispossessed (mass ppb. ed.). New York: Eos/HarperCollins. pp. 276. ISBN 0-06-105488-7. “‘They print Reumere’s plans for the ansible.’ ‘What is the ansible?’ ‘It’s what he’s calling an instantaneous communication device.’”
3. ^ a b Card, Orson Scott (July 1994) [1977]. Ender’s Game (mass ppb. ed.). New York: Tor Books. pp. 249. ISBN 0-8125-5070-6. “What matters is we built the ansible. The official name is Philotic Parallax Instantaneous Communicator, but somebody dredged the name ansible out of an old book somewhere and it caught on.”
4. ^ Vinge, Vernor (1988-11-01). “The Blabber”. Threats & Other Promises. Riverdale, NY: Baen. pp. 254. ISBN 0-671-69790-0. “‘It’s an ansible.’ ‘Surely they don’t call it that!’ ‘No. But that’s what it is.’”
5. ^ Moon, Elizabeth (1995-08-01). Winning Colors (mass ppb. ed.). Riverdale, NY: Baen. pp. 89. ISBN 0-671-87677-5. “…when I was commissioned, we didn’t have FTL communications except from planetary platforms. I was on Boarhound when they mounted the first shipboard ansible, and at first it was only one-way, from the planet to us.”
6. ^ Jones, Jason (with Greg Kirkpatrick) (1995-11-24) Marathon 2: Durandal, computer game, Chicago, IL: Bungie Software. “A connection [?ansible] was left; awaiting the next quiet [?peace]; and though destroyed by the threes, it will scream over the void one time.”
7. ^ Graf, L.A. [Julia Ecklar] (August 1996). Time’s Enemy (Star Trek Deep Space 9TM : Invasion, 3. mass pbk. ed.). New York: Pocket Books. pp. 203. ISBN 0-671-54150-1. “‘…The two Dax symbionts can communicate with each other across space, instantaneously, because they’re composed of identical quantum particles. I’ve become a living ansible, Benjamin.’”
8. ^ Simmons, Dan (2003-07-01). Ilium (hbk. ed.). New York: Eos/HarperCollins. pp. 98. ISBN 0-380-97893-8. “I can see Nightenhelser madly taking notes on his recorder ansible.”
9. ^ Herbert, Frank (1970-April) [1970]. The Whipping Star. Worlds of If magazine.
10. ^ a b Pullman, Philip (2001-10-02) [2000]. The Amber Spyglass (His Dark Materials, 3. mass pbk. ed.). New York: Del Rey. pp. 156. ISBN 0-345-41337-7. “‘Well, in our world there is a way of taking a common lodestone and entangling all its particles, and then splitting it in two so that both parts resonate together.’”
11. ^ Testing Spooky Action at a Distance Preprint: Testing Spooky Action at a Distance Nature Article
External links
* Ansible from the Oxford English Dictionary
* Science Fiction Citations project
* Ansible at Technovelgy
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