Comments, additions, suggestions, flames, etc. are welcomed. Copyright (C) 1994, Joshua Sean Bell. Not in the public domain.
Star Trek, Star Trek: The Next Generation and Star Trek: Deep Space Nine are registered trademarks of Paramount Communications.
"How does it work?"
The Holodeck uses 5 levels of simulation:
1) Things in the distance are holograms projected on the walls. (Like the wall in "Encounter at Farpoint" or "Ship In A Bottle".)
2) Nearby things are holograms projected into space. An example would be a tree or lamppost.
3) A fixed object that requires interaction is a combination of a projected hologram and shaped forcebeams. A good example might be steps or a wall.
4) A _static_ object which may be picked up, eaten, etc, is physically replicated onto the Holodeck. An example would be food, paper, a snowball, etc. These objects are independent once created, and may be carried off Holodeck intact.
5) An _animated_ object is comprised of a partially stable form of matter created by the transporter-based replicators for use in the holodeck. This material is stable only within a holodeck or holosuite, and degrades into energy if removed. (Encyclopedia). This is matter held in place by forcebeams operating at a molecular level, as opposed to actually replicating the object down to the molecular bonds. Without the forcebeams, the object disintigrates. Examples would be the gangsters in "The Big Goodbye", Picard's horse in "Pen Pals", or Minuet in "11001001".
Note that levels 1-4 are relatively trivial for the ship, while level 5 requires more computation time... which could explain Riker's surprise at Minuet (though he hadn't experienced her charms at that point). It may also have not been possible prior to the enhancements made by the Bynars in "11001001". This is supported by the Encyclopedia.
Note that if an object's status changes, the simulation type will change seamlessly as well. For example, someone sees a distant tree (hologram), approaches it and leans on it (forcebeams), breaks off a branch (holodeck matter), then picks and eats an apple (replicated).
Any food consumed on the Holodeck would be of level 4 simulation - it will be as real as replicated food from a replication terminal.
A 'meat puppet' is a old term resurrected to describe a replicated humanoid form created on the Holodeck, and dragged around by forcebeams. If the forcebeams failed, you'd be left with a limp, lifeless body.
Yes. Any object replicated on the Holodeck may leave. Unfortunately,
it is sometimes hard to tell what is replicated, and what is not.
Snow, such as the snowball thrown by Wesley in "The Naked Now" is
easily replicated, and dampness is hard to simulate. The book thrown
by Picard in "Ship In A Bottle" would be easily simulated by force
beams and thus was not replicated.
The paper in "Elementary, Dear Data" was likely simulated until the
computer realized that it was going to be carried off the Holodeck, at
which point it would have been seamlessly replaced with a replicated
copy.
According to various reliable sources, that was Gene Roddenberry's intention. If the paper could have left, Moriarty should have been able to, goes the logic. Fortunately, this scene was cut, and as always, canon is what we see on the screen, big or small. This means the whole argument against replicating people holds - that the computer cannot store that much information.
This has never been tried, as explained in the episode, which is why the computer was unable to simulate the results. Replicated objects should be able to be transported out of the Holodeck, but anything relying on the forcebeams would instantly collapse.
As for uncoupling the Heisenberg Compensators - that would give a random quantum state to each element of the transported object. It would be akin to a molecular-resolution transport - probably deadly for any living being.
"Now wait a second. How come something simple like the chair in TNG
"Ship In A Bottle" wasn't replicated?"
They were testing beaming something composed of the 5th type of simulation; an object made of holodeck matter, just like Moriarty and the Countess. Obviously a purely replicated chair wouldn't do for this experiment, so Geordi probably tweaked the chair to be the right kind of simulation to use for the test.
In "The Perfect Mate", Riker manages to croak out something about "I'll be in Holodeck 4..." after an encounter with the metamorph. No proof that he did anything, true. Minuet (in "11001001") was "As real as you need me to be." Uh-huh. Geordi doesn't seem to have much luck off the 'deck, it seems, nor does Reg Barclay.
Draw what conclusions you will.
"What if you urinate/defecate/excrete whatever on the Holodeck?"
One would hope the Holodeck is smart enough to clean up after you. It probably gets transmuted into some form the bulk matter stores can use, and saved for later use by replicators or the Holodeck again. The ultimate in recycling.
And, er, if another real person in the Holodeck is the... recipient of your, er, donation? The Holodeck doesn't interfere, and we have that little charmer, Alexander, to prove it. (Thanks to Benjamin Chee for pointing this one out.)
Yes. Even when it isn't malfunctioning, the simulation can't protect you from your own stupidity. Broken ribs and arms from cliff diving and other sports practiced on the holodeck are often seen treated in Sick Bay.
"But the replicators can't even make unhealthy food!"
Replicators can (within limits of technology and energy) produce anything for which they have a pattern. Certain objects may need security clearance. But you can have the replicator make a glass of water, and use the glass as a weapon - it may be smart, but it's not foolproof. (Benjamin Chee points out that it is transparent aluminum anyway, so you couldn't break it to get an edge. On the other hand, we have seen glasses shatter when knocked from tables...)
Its intended use was as a way to program the Holodeck and access the ship's computer, as well as a virtual reality safeword. In later episodes, they just used the "exit" and programmed the computer by voice. It is still around, recently seen in "Ship In A Bottle". The arch was how Moriarty first learned that he was a simulation, and gained control of the ship in "Elementary, Dear Data".
"How do they manage to keep walking for hours and hours?"
The Holodeck has a forcefield treadmill. If its occupants get too close to the walls, they are shifted away. Since the Holodeck can modify its gravity in 3 dimensions, the occupants won't notice any inertial change. The novel "Reunion" (while non-canon) goes into details about this.
"But what about the walls seen in "Encounter at Farpoint" and "Ship In
A Bottle", demonstrated by Data?"
In "Encounter at Farpoint", Data threw a Holodeck-generated rock at the wall. There are a few possibilities. Either the computer realized the intent of the demonstration, and didn't replace the rock with an image on the Holodeck wall; or the "simple pattern" of that simulation didn't allow for treadmill-scrolling; or the Holodeck computer wasn't quite powerful enough, pre-Bynar intervention.
In "Ship In A Bottle", Data throws his own communicator at the wall. The Holodeck must have safeguards not to summarily destroy things it didn't create, so it didn't do anything to affect the communicator.
The simplest answer is that the Holodeck "compartmentalizes", in effect becoming a separate Holodeck for each person within it. In reality, the two people would probably be only a few meters apart, but would be separated by a Holodeck-projected "wall". If they turned to look at each other, they would see an image of the other projected on that wall.
"What if they take a real rock in with them, walk away from each other (past the physical limits of the Holodeck) and then toss the rock back and forth?"
This one is too easy. Assume the rock is sentient. When it leaves the hand of the thrower, the holodeck "wraps" it in its own miniature simulation, and hides it from the two people, who (in their own mini-Holodeck) see only an image of the rock. The rock is then moved (with forcebeams) from the thrower to the catcher, given the appropriate kinetic energy along the way. From the rock's point of view nothing out of the ordinary happens.
"So what if two people take a long rope, and start walking away from
each other?"
The answer in this instance could be that the Holodeck hides part of the rope, and projects an image of a tightening rope along with forcebeam-generated tension.
In general, though, the answer to these "boggle the Holodeck"
questions is that no, it's not perfect. You will encounter limitations
to the technology, and gaps in the 'reality' will become apparent.
However, you really do have to be looking for problems to find them.
According to the TNG TM, the Enterprise has three main computers. Two reside in the Primary Hull (the saucer); they are vertical cylinders, about 8 decks high, and located on opposite sides of the saucer, flanking the bridge. The third computer is located in the Secondary Hull (engineering), and is smaller than the other two cores; it controls the Stardrive section when the ship separates.
We've seen the computer cores a number of times. In TNG "Evolution" the nanites were attacked in the computer cores. The set is probably meant to be just one deck of the multi-deck computer core, with the room seen the hollow central portion.
The computers are networked with each other, and with the rest of the ship via the ODN - the Optical Data Network. The ODN has enough processing power on its own to take over limited control of the ship in case of a complete computer failure.
....
"Why aren't the computers distributed?"
The three main computer cores are equipped with low level subspace field generators. This allows signal propagation within the cores at Faster-Than-Light (FTL) speeds, allowing the computers to perform much faster than anything constructable given 20th century technology, even theoretically. This cannot be applied (by 24th century technology) to smaller computers.
....
"Why do the displays and touchpads work when the computers are down?"
The displays use "nanoprocessors" - cell sized mechanical computers - to display information. The display itself contains data polled from the ODN, and based on user selections, displays whatever is appropriate. So even if the computers go down, whatever information is (1) already on the ODN (or ODN backups) or (2) in the display itself can be selected and displayed.
....
"How big is a kiloquad?"
This hasn't been answered, and Michael Okuda is reported to have said it *won't* be answered, as any number he could come up with would be obselete before the series ends.
However, many r.a.st.tech contributors have converged on kiloquad to mean 1000 (kilo) * 1 quadrillion bytes (or bits, but we'll stick with bytes for the explanation), the premise being that a "quad" came into use instead of "pet" for Petabyte, and the kilo- prefix was added as "ex" for Exabyte was equally silly. That makes one kiloquad = 2^60 bytes ~= 1 billion gigabytes, or 1 million million megabytes. Thats a fair amount.
Is this technologically feasable, given that an isolinear chip, quoted at 2.15 kiloquad in the TNG TM is about the size of a microscope slide?
From H. Peter Anvin:
...The 2.15 kqd isolinear chips [would have] a bit density of 2.94e+15 bits/mm^3 (I have assumed the dimensions to be 90x30x2.5 mm, this is probably on the high side if you exclude the part where you handle the chip); that means each bit could form a cube 7.0 nm (70 [angstrom]) to the side. The chips are optical, which I assume means they are read and written with electromagnetic radiation that behaves somewhat approximately like light. 7 nm is in the far ultraviolet region-near X-ray region (visible light ends at about 200 nm) which is really pushing the limit. Assuming some form of multi-state encoding that may exist may push this down to near UV which would then be a bit more practical to deal with, and more "optical", but that is irrelevant.
Hence, what we "know" about ST computer technology seems to correlate pretty well to the definition 1 quad = 1 quadrillion bytes. It may be bits or bytes (it is only a factor of 8, obviously... it changes 7 nm to 14 nm if it is bits not bytes), but it seems to fit pretty well.
....
"But a quad is a unit of energy!"
Words can have more than one meaning.
John F. Meyer Jr.
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See the Reading List Mini-FAQ for full details on the volumes
mentioned above and below.
More recently presented information is considered to supercede old
information, unless the weight of the evidence supports the original
data.
Greatest priority is placed on aired live-action material (canon) and
documents produced by or quoting the production crews for Star Trek
(quasi-canon), most notably the Technical Advisors to ST:TNG and
ST:DS9, Michael Okuda and Rick Sternbach.
Other materials are not considered reliable sources of information,
and anything gleaned from these is of questionable relevance.
Canonical Material:
Questionable (but useful) Materials:
Material that is ignored (other than where it reproduces material from
the above, e.g. photographs, descriptions, etc.):
H. Peter Anvin
Benjamin Chee
6. References:
Quasi-canonical Material:
Joshua Sean Bell