A holodeck is a room equipped with a hologrid containing omnidirectional holographic diodes, which enable holographic projections.
Purpose and design
The holodeck serves both entertainment and training purposes. It combines transporter technology with that of replicators, by generating holographic images in 3D space as well as projecting force fields to give the objects the illusion of substance. It can be controlled from an exterior control or the interior arch control. This arch can be summoned at any time to change the parameters of a running holoprogram.It was discovered that matter and energy are interchangeable. (TNG: "Elementary, Dear Data")
Holodeck walls can generate holographic images that appear to extend for an unlimited distance, seemingly much larger than its own dimensions. In doing so, however, the holodeck is aware only of its users; it does not recognize its own created objects. For example, if a person were to throw a holographic rock at the holodeck's walls, the rock would not be allowed to pass beyond the wall. (TNG: "Encounter at Farpoint") It does this by continuously adjusting the projections of the force fields and the use of a force field "treadmill". With this, an individual approaching a wall causes an instant shift away. The holodeck can change gravity in three dimensions, so occupants don't notice the change, (Star Trek: The Next Generation Interactive Technical Manual) as observed during the stop of B'Elanna Torres' holographic orbital skydiving session. (VOY: "Extreme Risk")
Holodeck matter can impersonate real matter even at the molecular level. (VOY: "Phage") Molecule-sized magnetic bubbles replace molecules in full resolution holographic objects. The computer can manipulate them individually in three dimensions. The computer may use large magnetic bubbles to simulate surfaces and textures rather than create an object at the molecular level. However, objects created within the holodeck would not exist beyond the holodeck itself, as they only exist as energy. (TNG: "The Big Goodbye")
A holodeck can modify the appearance of the persons in it. In Tom Paris' holoprogram "Captain Proton", everything and everyone can only be seen black and white. Seven of Nine used the holodeck to hide her cybernetic implants. (VOY: "Human Error") However, it is unclear if this illusion works for Humans, because the only "persons" attending the program were Seven herself and the Doctor, who himself was holographic.
Holograms can be augmented with force beams to simulate solid, tangible objects or with replicator technology to create actual solid matter such as foodstuffs. All food eaten on the holodeck are replications. No other type of simulation would survive outside of the holodeck.
A holodeck also has the ability to create holodecks within holodecks, and holodeck programs are able to be saved to a cube that can be inserted into special devices with information to "last a lifetime". (TNG: "Ship in a Bottle")
Computers cannot duplicate the complexity of electron shell activity and atomic motions that determine biochemical activity in living creatures. This prevents replicators from duplicating life and resurrecting the dead. Advances in computer technology may allow this, permitting a person to live forever in any chosen environment while interacting with real people and objects visiting the holodeck.
The energy matrix of a holodeck is incompatible with other ship systems. (VOY: "Parallax")
Failure of a holodeck's matter conversion subsystem can cause the loss of solid objects within the holodeck environment. Materialization errors occurred in the USS Enterprise-D holodecks in 2370 following the ship's exposure to plasmonic energy in the atmosphere of the planet Boraal II. (TNG: "Homeward")
Among the viewing modes on a holodeck is objective mode, in which the user doesn't interact with the characters, and subjective mode, in which the viewer can interact with the characters as well as alter his or her surroundings. (ENT: "These Are the Voyages...")
- There are many discrepancies between episodes pertaining to the abilities and limits of holodeck technology. In "Elementary, Dear Data", a piece of paper given to Data by James Moriarty is able to be carried outside of the holodeck and into the hall, but upon Moriarty's return in "Ship in a Bottle", a book thrown outside of the holodeck instantly disappears. Also, in "The Big Goodbye", Cyrus Redblock and Felix Leech disappear slowly after a few moments outside of the holodeck. Although these inconsistencies can be partially explained by the difference in the types of objects leaving the holodeck, it still leaves quite a few questions about what exactly constitutes the differences. The Holodeck can use a degree of replication to make realistic objects for the holodeck occupant to use, so there is a possibility of the computer replicating a real piece of paper with the picture on, as it would be a relatively simple pattern.
Early holodeck technology
Prior to the late 24th century, Federation starships were not equipped with holodecks. (VOY: "Flashback") However, in 2151, the Starfleet spacecraft Enterprise NX-01 encountered a vessel belonging to an alien race known as Xyrillians, who had advanced holographic technology in the form of a holographic chamber similar to the holodeck, which Federation Starfleet would develop two centuries later. A holo-chamber was later installed aboard a Klingon battle cruiser, given to the Klingons by the Xyrillians in exchange for their lives. (ENT: "Unexpected")
In the 23rd century, Template:ShipClass starships were equipped with a recreation room, which employed holographic technology. The USS Enterprise had a recreation room located in Area 39 of the ship. (TAS: "The Practical Joker")
The Ferengi entrepreneur Plegg is credited with the development and introduction of the holosuite, a holographic chamber designed for use by one occupant at a time. (DS9: "The Alternate")
Federation holodecks
By 2364, the Federation Starfleet had begun installing holodecks aboard their vessels. (TNG: "Encounter at Farpoint")
Federation holodecks are equipped with safety protocols to prevent serious injury during their use, although these can be disengaged by the user when required. If a force field would cause a certain level of physical harm to a living person that field collapses, allowing the person to escape uninjured. For instance, holographic bullets could be made lethal by simply turning off the holodeck safety protocol. (TNG: "The Big Goodbye", Star Trek: First Contact)
How the security protocols are circumvented differs. In one instance, it required the voice authorization of two senior officers. (TNG: "Descent") In other instances, the authorization of the individual who started the program was enough. (VOY: "Extreme Risk")
Holodecks employ spatial orientation systems to simulate parts of a holocharacter, such as left- or right-handedness. (TNG: "Ship in a Bottle")
Holodeck characters have been known to include a program element designed to hide anachronisms to the program's time period, such as uniforms and communicators, and prevent them from raising the character's ire and curiosity.
During the 2360s and 2370s, a starship could have one or more holodecks depending on the vessel's size or purpose. For example, Template:ShipClass starships did not have a holodeck, while Template:ShipClass vessels had several. (TNG: "11001001", "Homeward") The two holodecks of Template:ShipClass starships were the only places where the EMH can exist (without a mobile emitter) apart from the sickbay. In Template:ShipClass starships, the EMH could move more freely because all decks were equipped with holoemitters. (VOY: "Message in a Bottle")
Holoprograms
Starships with a holodeck normally had a vast list of holoprograms in their computer. Several notable programs aboard the USS Enterprise-D included:
- A woodland setting, resembling Earth, which featured a rock-jumping challenge, some of which were seemingly impossible to complete. (TNG: "Encounter at Farpoint")
- A New Orleans jazz nightclub. (TNG: "11001001")
- A recreation of the voyage on the Orient Express. (TNG: "Emergence")
- Sherlock Holmes mysteries, where the user assumed the role of Sherlock Holmes and/or Dr. Watson (TNG: "Elementary, Dear Data", "Ship in a Bottle")
- Prospero's island, decor for Shakespeare's The Tempest. (TNG: "Emergence")
- Café des Artistes – "Enjoy a meal at a French cafe." (TNG: "We'll Always Have Paris")
- Champs Elysees – "Famous section of Paris."
- Charnock's Comedy Cabaret – "Laugh in a 20th century comedy club." (TNG: "The Outrageous Okona")
- The Big Good-Bye – "The 1940s world of gumshoe detective Dixon Hill." (TNG: "The Big Goodbye", "Manhunt", "Clues")
- Cliffs of Heaven – "From planet Sumiko IV, a safe experience." (TNG: "Conundrum")
- Equestrian Adventure – "Horse riding in an open country..." (TNG: "Pen Pals")
- Calisthenics Program of Lieutenant Worf – a swamp-like setting where various alien enemies tested ones fighting skill. (TNG: "Where Silence Has Lease", "The Emissary")
- The bridge of the USS Enterprise – the user could select any of the five (at the time) bridges of the various Federation starships named Enterprise to view. Captain Montgomery Scott only wanted to see the original Enterprise bridge, "no bloody A, B, C, or D." (TNG: "Relics")
- The Final Mission of Enterprise – this program allowed a user to view or take part in the final mission of the NX-01 Enterprise, commanded by Captain Jonathan Archer, as well as showcasing the signing of the Federation Charter. (ENT: "These Are the Voyages...")
- Natasha Yar's Living Will – designed by Lieutenant Natasha Yar to be played in the event she was killed, where she bid farewell to her comrades. The Enterprise bridge crew unfortunately had to watch the program when Yar was killed by Armus on Vagra II. (TNG: "Skin of Evil")
- Celtris III Underground – a simulation where the users could prepare for missions on the Cardassian planet of Celtris III. (TNG: "Chain of Command, Part I")
- Lieutenant Barclay's various programs – these included a mock-up of Ten Forward, where the user could attack Commander Riker and Lt. Commander Geordi La Forge to "blow off some steam" as well as win the heart of Deanna Troi; a mock-up of Counselor Troi's office where the user could receive counseling from a hologram rather than the real Troi; a woodland setting where the user could duel with recreations of Captain Picard, Data, and La Forge in a sword-fight, complete with a recreation of Deanna Troi as "The Goddess of Empathy"; a mock-up of the Enterprise-D bridge, where the user could bid farewell to the bridge crew; the Einstein program where the user could debate mathematics and science with Albert Einstein; a synaptic interface where the user could control the main computer of the Enterprise with the power of their own thoughts (however, removal of the user by conventional means would result in death); and various other programs. (TNG: "Hollow Pursuits", "The Nth Degree")
- A game of poker with three famous scientific minds: Albert Einstein, Sir Isaac Newton, and Stephen Hawking. (TNG: "Descent")
- USS Enterprise – an 18th century Earth brig. (Star Trek Generations)
Notable programs aboard the USS Enterprise-E included:
- The Big Good-Bye – "The 1940s world of gumshoe detective Dixon Hill." (Star Trek: First Contact)
Notable programs aboard the USS Voyager included:
- Chez Sandrine (VOY: "Phage")
- Janeway Lambda one (VOY: "Learning Curve")
- Paxau Resort (VOY: "Warlord")
- Insurrection Alpha (VOY: "Worst Case Scenario")
- Leonardo Da Vinci's Workshop (VOY: "Scorpion")
- The Adventures of Flotter (VOY: "Once Upon a Time")
- Velocity (VOY: "Hope and Fear")
- The Adventures of Captain Proton (VOY: "Night")
- Fair Haven (VOY: "Fair Haven")
- Photons Be Free (VOY: "Author, Author")
- Holographic family (VOY: "Real Life")
Notable programs aboard the USS Enterprise's recreation room included:
- A beach setting allowing for swimming.
- A woodland environment allowing for a nature walk.
- An arctic wasteland.
- An 18th century style hedge-maze. (TAS: "The Practical Joker")
Background
For its first appearance on Star Trek: Voyager in "The Cloud", the exterior of the holodeck was the same set piece as had previously been seen on TNG, right down to the octagonal door frame, although all had been repainted to match the color scheme for the new Voyager corridors. It would not receive a square door arch and updated door panels until its second appearance.