||This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. (January 2013)|
A holodeck on the Enterprise-D; the arch and exit are prominent.
|Plot element from the Star Trek franchise|
|First appearance||Star Trek: The Animated Series
"The Practical Joker"
|Created by||Gene Roddenberry|
|Type||Simulated reality facility|
|Function||Creates artificial environments for recreational or training purposes|
A holodeck, in the fictional Star Trek universe, is a simulated reality facility located on starships and starbases. The first use of a "holodeck" by that name in the Star Trek universe was in the pilot episode of Star Trek: The Next Generation, "Encounter at Farpoint", although a conceptually similar "recreation room" appeared in an episode of Star Trek: the Animated Series.
In the timeline of the fictional universe, the concept of a holodeck was first shown to humans in an encounter with the Xyrillan race in the Star Trek: Enterprise episode "Unexpected". During a scene from Star Trek: First Contact that took place 100 years before the events of Enterprise, Jean-Luc Picard was in Earth's past and had a human from that time period named Lily along with him on board the Enterprise. When they were running from the Borg on his starship they hid in the holodeck, therefore introducing the technology before the events of "Unexpected".
||This Star Trek-related section describes a work or element of fiction in a primarily in-universe style. (January 2013)|
The holodeck is depicted as an enclosed room in which objects and people are simulated by a combination of transported matter, replicated matter, tractor beams, and shaped force fields onto which holographic images are projected.
Most holodeck programs shown in the episodes run in first person "subjective mode", in which the user actively interacts with the program and its characters. The user may also employ third-person "objective mode", in which he or she is "apart" from the actual running of the program and does not interact with it (all of the program's characters will ignore the user as if he or she was not there—this was shown in the Enterprise episode "These Are the Voyages...").
Matter created on the holodeck ("holomatter") requires the holoemitters to remain stable and will quickly disintegrate if it is removed from the holodeck without a mobile emitter to sustain it, although this principle has been overlooked in some episodes. Writer Phil Farrand has often pointed out how in many episodes matter from the holodeck that gets on a real person still exists when the real person exits the holodeck. In "Encounter at Farpoint", Wesley Crusher falls into a holodeck stream, but is still wet after exiting the holodeck. In "The Big Goodbye", Picard has lipstick on his cheek after encountering a holodeck simulation of a 20th-century woman. In "Elementary, Dear Data", Data and Geordi La Forge exit the holodeck with a piece of paper that originated in the holodeck. This could be explained using replicated rather than holographic matter.
In most episodes, the holodeck is controlled by voice commands, though physical controls have been shown in a few episodes. They also include safety protocols to protect the users.
Some users may develop an addiction to the holodeck (a condition known as "holodiction"), leading to them spending unhealthy amounts of time there and personifying artificial characters. This was demonstrated by the Starfleet human character Reginald Barclay in the Voyager episode "Pathfinder" and The Next Generation episode "Hollow Pursuits".
Although the holodeck was described in the first season of Star Trek: The Next Generation as being fairly new technology (on starships), in the episode "Once Upon A Time" Captain Janeway and Harry Kim mention having used a holodeck as children.
The Star Trek Holodeck was inspired by New York inventor and holographer, Gene Dolgoff, who is also the inventor of the digital projector. His holography laboratory, built in 1964, was the first holography lab in New York City.
In 1973, Dolgoff was giving a technical paper on his holographic model of the human brain at a conference in Prague. There he met Melanie Toyofuku, also based in New York, who became a close friend of Dolgoff's. After spending a great deal of time with Dolgoff learning about his pioneering work in holography, including visiting his holography laboratory in New York City, Melanie introduced him to her close friend Gene Roddenberry, who was visiting New York with his wife Majel Barrett in late 1973.
Dolgoff spent the day with Roddenberry and his wife showing them many holograms and explaining his theories of "matter holograms", the holographic nature of the universe, and the holographic nature of the human brain. Dolgoff emphasized the importance holography will play in the future and that if Gene Roddenberry wanted to be accurate he must introduce holography into his Star Trek scripts, including the concept of a holographic "room" for the crew to use for amusement, training, and other purposes.
Dolgoff had won 4th prize in the IEEE student paper contest in 1968 in which he described how such a holographic "TV system" could work (in addition to describing how to use it to provide a machine capable of invisibility). Roddenberry wrote the concept into Star Trek: The Next Generation, in its debut in 1987. However, the concept had already been tested in 1974 in Star Trek: the Animated Series.
Starfleet personnel use holodecks for training, diagnostics and recreation. Holodecks are used to recreate or simulate settings and events for analysis, such as to explore the forensics and logistics of a crime scene for law enforcement purposes, or for scientific experimentation. In general, the holodeck "functions as a cultural repository of narrative possibilities that would normally be excluded from the ship's own sociohistorical moment" and "allows the Enterprise community to include even that which it excludes by containing the excluded within a proper, controlled place which in no way intrudes upon the everyday space of the ship."
Writing stories and plotlines for the holodeck is an activity pursued by people known as holonovelists. It was the chosen profession of Lt. Tom Paris of the USS Voyager, and he pursued it when the ship finally returned from the Delta Quadrant in the show's finale.
The Holosuites and holodecks utilize two major subsystems: the holographic image and the conversion of matter. The holographic imaging system creates realistic environments and landscapes. The conversion system of matter creates physical objects from the central supply of raw materials from the ship. Under normal conditions, a participant in a holographic simulation should not be able to distinguish a real object from a simulated one.
The holodeck also generates impressive recreations of humanoid and other forms of life by means of precisely-shaped force fields covered by holographic imagery, with the effect that they seem solid to the touch. They are made to move by use of tractor beams, resulting in highly articulated and computer-controlled "puppets" which are exceptionally realistic, showing nearly equal behavior to that exhibited by living beings, depending, of course, on the limits of the software involved. However, the replication-based material transport system is obviously unable to reproduce a living being.
Solid, inanimate objects on the holodeck—items such as a book, a rock, or an apple—are composed of matter arranged by the replication system and, when deemed appropriate by the computer system, can be interacted with or even consumed. Objects created by replication of matter are physically real and can indeed be removed from the holodeck, noting only that they will no longer be under the control of the computer once removed from the simulation. However, objects created on the holodeck that are purely images can not be removed from the simulated environment, even if they seem to have a physical reality due to the force fields. In order for a given item to be removed from the environment of the holodeck, a person would need to be holding the object as he/she leaves.
The basic mechanism behind the holodeck is the omnidirectional holo-diode (HDO or OHD, its acronym in English). The HDO comprises two types of micro-miniature devices that project a variety of special force field. The density of HDOS in a holographic surface is 400 per square centimeter, fed by an outlet electroplasma medium power. Entire walls are covered with HDOS, manufactured in an inexpensive process of printing circuits on a roll.
A typical surface holodeck includes twelve sub-layers processed a total of 3.5 mm, fused to a thermal-structural light panel, which on average is 3.04 cm thick. The primary materials include sub-processor/emitter of superconducting material. Each individual HDO measures 0.01 mm. The mechanism of digital optical network, by which an HDOS receive impulses, is similar to that which feeds smaller display panels, although the walls are divided into major sections, and easier to control with greater speed, each with 0.61 m². Sub-sections which are dedicated to the main computer can control such "monitors" which are the size of rooms.
Besides the ability to project stereoscopic color images, HDOS manipulate the force fields in three dimensions to allow visitors to "feel" objects that are not really there. This tactile stimulus provides the appropriate response one would expect from a rock on the ground or a tree growing in a forest. The only factors limiting the number and types of object are given by the computer memory and time to retrieve or calculate the beginning pattern of an object, either real or imaginary.
The version of "optics" of a HDO sends a complete picture of the environment or landscape, based on their location relative to the full panel. The visitor, however, sees only a small portion of each HDOS, almost like a fly's eye operating in reverse. When the visitor moves the visible portions of HDOS change, changing the perspective. In reality, the energy emitted is not a visible electromagnetic emission, but is actually polarized patterns of interference. The image is reconstructed where the patterns intersect the lens of the eye or any visual receiver.
Notable appearances 
It has been noted Star Trek has "a number of interesting 'holodeck' episodes that very roughly point towards interesting philosophical and sociological issues of virtual realities".
The first episode featuring a holodeck was "The Practical Joker", an animated episode in which it was called a "recreation room". Due to interference with the ship's computers, several crew members were trapped in it until the engineering crew managed to force open the doors.
There were several incidents of crew being trapped or injured by holodeck malfunctions in later episodes. One resulted in the shooting of the ship's historian on board Enterprise. In the episode "A Fistful of Datas", Lt. Worf, his son Alexander, and Counselor Troi were trapped in a 19th century American West adventure with the safety protocols disabled when a computer experiment involving Lt. Cmdr. Data went awry. Worf received a minor gunshot wound when the computer began remaking all the characters as replicas of Data. However he was able to safely play out the story, and once the story ended the trio was able to leave the holodeck. Jean-Luc Picard experiences an upgraded holodeck in "The Big Goodbye", in which he portrays the detective Dixon Hill, a boyhood hero of the captain's. This episode establishes the power and function of the holodeck. A malfunction leads to Data, Jean-Luc, and Beverly Crusher being trapped on the holodeck. Picard portrayed the character again in Star Trek: First Contact.
The disabling of a holodeck's safety protocols was used as a tactical advantage in Star Trek: First Contact, when under attack from the Borg, Jean-Luc Picard disables the security protocols and grabs a holographic tommy gun, shooting and killing two Borg drones.
The holodeck was used as a plot device to explore metaphysical questions, in such episodes as "Elementary, Dear Data" and "Ship in a Bottle", in which a holodeck character becomes self-aware and contemplates the nature of his identity and continued existence. In Michio Kaku's TV series Sci-Fi Science: Physics of the Impossible, he discussed the Holodeck in an episode entitled Hollodeck.
Usage in Star Trek: Voyager 
In Star Trek: Voyager the holodeck was used extensively because (1) a crew isolated from their homes required more frequent diversion, (2) the holographic Doctor could, in the early seasons, be located only in the Sick Bay or one of the holodecks, (3) one of the main characters, Tom Paris, was by nature and calling a writer (holonovelist).
Significant/Innovative uses of the holodeck in Star Trek Voyager include: the existence of alien "Photonic Lifeforms" who interact with the "Organics" on board Voyager primarily through the holodecks; the introduction of children's holonovels; and the long-term use of holodeck locations as gathering places for all crew members:
Captain Janeway gives holo-technology to the hunter-race the Hirogen after they take over Voyager for an extended period of time and use the ship's holodecks (safety protocols off) to hunt down the members of the Voyager crew in (what they consider) intriguing holographic environments. Episode "Flesh and Blood" reveals that the Hirogen's improvements (designed to create more challenging holographic prey) have essentially created a new race of photonic beings.
In Episode "Nothing Human" a holographic version of a real-life war criminal (whose unethical research helps save a crew-member's life) is held responsible for the crimes of the Cardassian he was modeled upon.
A holonovel "Photons Be Free" authored by the Doctor (Episode: "Author, Author") raises the issue of whether the holographic Doctor is a person and has any legal rights, and ends showing dozens of copies of the Doctor mining dilithium by hand for the federation, essentially as slaves.
Similar technology in other works 
- Ray Bradbury was perhaps the first science fiction author to envision a simulated environment similar to the holodeck. His 1951 book of short stories, The Illustrated Man, includes a story called The Veldt, in which a children's nursery can create material objects based on thought.
- In 1965, computer scientist Ivan Sutherland stated: "The ultimate display would, of course, be a room within which the computer can control the existence of matter. A chair displayed in such a room would be good enough to sit in. Handcuffs displayed in such a room would be confining, and a bullet displayed in such a room would be fatal."
- In the 1973 Russian science-fiction movie Moscow-Cassiopeia, a "Surprise Room" operated in the same way as the holodeck in Star Trek: The Next Generation.
- The 1974 Japanese TV series Space Battleship Yamato (Star Blazers in English syndication) features a "resort room" which allowed the crew to combat homesickness by immersing themselves in simulated scenes of Earth.
- In the X-Men comic book series, the X-Men train in the Danger Room. In the earliest version of this room depicted in the 1960s, the Danger Room utilized mere mechanical devices to simulate threats, but the version depicted following an upgrade by the extraterrestrial Sh'iar in the early 1980s utilizes sophisticated holograms, robots, and other sensory simulation to create environments as realistic as those on the holodeck. In the film X-Men: The Last Stand, the Danger Room's holography is shown to be a combination of light projection and solid objects.
- In the science fiction television series Stargate SG-1 and Stargate Atlantis, some advanced races (such as the Asgard and the Ancients) have holo technology, albeit generally not to the extent of a Star Trek-style holodeck.
- In the series Jake 2.0, the protagonist was seen training in a holographic room in one of the early episodes.
- In the series Power Rangers: S.P.D., the Rangers train in a similar room on at least two occasions.
- In Futurama, the Nimbus is equipped with a "holoshed", a parody of the holodeck.
- Madden NFL 09 features a "holographic environment" for players to train.
- In the film Spy Kids, Fegan Floop uses a holodeck-like room known as the "virtual room" as a film set for his television show.
- In the Nintendo 64 game Perfect Dark, players can use a holo room for basic training purposes.
- In Power Rangers in Space, the Power Rangers use the Simudeck on the Astro Megaship to train and exercise.
- In the Show Squidbillies, (episode "Holodeck Redneck") The Sheriff uses a holodeck to distract Early while he repossesses his truck-boat-truck-boat-truck-wave-runner, which in fact happened inside a holodeck within a therapist's office as a fantasy of The Sheriff's, which in turn took place inside a holodeck in the therapist's office as a part of one of Early's fantasies.
- Albeit being a police procedural rather than a SF-show, the medical examiners in CSI: NY use a holodeck frequently.
- In 2011 author A. A. Farr created a similar environment in the book Koschei: The Conclusion: A Fallen Hero. The concept took place in a large black building said to be used for training, but once inside a city would be before you. The building contained a mix between fluctuating reality and virtual reality by a means of magic and imagination, and was in actuality just one large room.
- In Future Boy Conan episode The Solar Tower, Lao shows the kids the Triangle Tower's virtual park, which works similarly to the Holodeck
- In Community, Troy and Abed have a room in their apartment painted to resemble a deactivated "Next Generation" holodeck. The room itself is non-functional as an actual holodeck because the technology does not exist since the series is set in the present day, everything represented in this room are figments of Troy and Abed's over-active imagination.
- In the George Michael music video, Fastlove, the music video takes place in a holodeck like environment, with all the user's fantasies coming to life.
See also 
- Artificial reality
- Augmented reality
- Brain-computer interface
- Cave Automatic Virtual Environment
- Haptic technology
- Methods of virtual reality
- Mixed reality
- Narrative environment
- Omnidirectional treadmill
- Simulated reality
- Treadport Active Wind Tunnel
- Virtual reality
- Virtual retinal display
- Virtual world
- Volumetric display
- Phil Farrand. The Nitpicker's Guide for Next Generation Trekkers New York: Dell (1993)
- Sarah Hardy & Rebecca Kukla, "A Paramount Narrative: Exploring Space on the Starship Enterprise" The Journal of Aesthetics and Art Criticism 57 2 (1999): 182.
- Ford, Paul J. (2001). "A further analysis of the ethics of representation in virtual reality: Multi-user environments". Ethics and Information Technology (Kluwer Academic Publishers) 3 (2): 113–121. doi:10.1023/A:1011846009390.
- Thomas Richards, The Meaning of Star Trek. New York: Doubleday (1997): 108 - 109. The Enterprise-D "has two mechanisms aboard that seem especially prone to failure ... the transporter and the holodeck."
- Richards (1997): 114
- Sutherland, I. (1965). The ultimate display. Proceedings of IFIP Congress 1965, 506-508.
- P. Farrand, Nitpicker's Guide for Deep space Nine Trekkers New York: Dell (1996): 44 - 47
- Lois H. Gresh & Robert Weinberg, Chapter 7, "The Holodeck" The Computers of Star Trek. New York: Basic Books (1999): 127 - 144
- R. Sternbach & M. Okuda, Star Trek: The Next Generation Technical Manual New York: Bantam Books (1991)
- Gene Dolgoff, "Reproduction of Transmitted, Pre-recorded, Holographic Television Signals in Color" New York: Institute of Electrical and Electronic Engineers (IEEE)(July, 1968)
- Holodeck at Memory Alpha (a Star Trek wiki)
- Holodeck and Computers FAQ by Joshua Bell
- Holodeck Technology