Holodeck - Features

Features

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. Sounds and smells are simulated by speakers and fragranced fluid atomizers, respectively. The feel of a large environment is simulated by suspending the participants on force fields which move with their feet, keeping them from reaching the walls of the room (a virtual treadmill). One notable instance of this being overlooked was in "Encounter at Farpoint" where Lieutenant Data demonstrates to Commander Riker that they are very near the back wall of the holodeck by picking up a rock and throwing it against the wall, briefly disrupting the optical image. This also demonstrates another gaffe when the rock that Data throws should interact with the simulation by being dissolved and simply displayed to Riker and Data as the image of a rock being throw into the distance, instead of a physical object that breaks the illusion by striking the invisible wall.

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 they were 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.