I know lots of Sci-Fi works use the term subspace. How does Subspace work? Is it like hyperspace (a parallel realm to our own)? or is it a host of alternate time lines that run parallel to our own? or is just a plot device used by Star Trek writers?

I know subspace has been used a lot in almost all Star trek related work. It's been used as a communication method, its been used as a term in Warp Drive, its used to explain alternate timelines, its used to explain where strange aliens lived, its even been used to explain away strange celestial phenomenon. So what is it, really?

On a side note, Star Gate uses it for various methods to... but I'm talking about in relations to the idea of "SubSpace" not to a particular Sci-Fi universe.

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    I like subwarp-drives. All the speed of warp, without all the warpedness.
    – riv_rec
    Commented Apr 28, 2011 at 15:58
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    As the Wiki says: Subspace (BDSM), the psychological state of the submissive partner in a BDSM scene Commented Apr 28, 2011 at 16:54
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    This is why I asked, Wiki is not always helpful. Commented Apr 28, 2011 at 17:06
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    As far as I can tell, “subspace” is Star Trek's name for hyperspace. It's definitely not a distinct generic concept across SF.
    – user56
    Commented Apr 28, 2011 at 18:05
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    @Asmor: But is there any difference between “subspace” and “hyperspace”, or for that matter with “magic-tech-that-allows-faster-than-light-travel-or-communication”?
    – user56
    Commented Apr 28, 2011 at 18:25

4 Answers 4


In general, subspace (sometimes referred to as Hyperspace), is the idea of going into dimensions beyond our regular 3 space+time dimensions.

The closest visual analogy would be is a Star Trek universe was 2-dimensional on a sheet of paper; and someone bent that paper into a cylinder. Then you could jump off of the sheet of paper in point A, travel in "hyperspace" (basically, the 3-d space around the sheet) to any other place on that sheet of paper - usually faster than travel on paper itself since the 3-D distance would be shorter than perceived 2-D distance on paper.

A real-life idea of a hyperspace is less than plausible, since even if there are dimensions above the 3+1 (as for example postulated by String Theory's 11-dimensions model), the extra dimensions are theorized to be "compacted" (think hairy carpet with hairs being small loops - they are in 3d dimension relative to the rest of the 2D carpet but you can't use them to travel from one point of the carpet to the next.

  • Sortof, but doesn't explain why Star Trek people believe it to be a lesser space. And why holes in subspace appear often but are not considered dimensional rifts? Commented Apr 28, 2011 at 17:02
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    @Justin - for specifics of how subspace works in Star Trek, see en.wikipedia.org/wiki/Subspace_%28Star_Trek%29 and en.wikipedia.org/wiki/Hyperspace_(science_fiction)#Star_Trek . I'm not sure what you mean by "lesser" Commented Apr 28, 2011 at 17:05
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    @Justin - ??? The link in the answer itself is for all the realms. Your first comment asked about star trek specifically thus I replied with ST specific links Commented Apr 28, 2011 at 17:38
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    Re: "(sometimes referred to as Hyperspace)", not sure I agree with that statement. Certainly the subspace and hyperspace are similar concepts that frequently serve the same role, but I'm not aware of any examples of a series using the terms interchangably. Most series will use one or the other. Some use both for different purposes (e.g. Stargate uses Subspace for communication and Hyperspace for FTL travel).
    – Asmor
    Commented Apr 28, 2011 at 18:15
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    @Asmor - please see the Wiki link in the answer. It explicitly explains that Star Trek's subspace is the same as general term Hyperspace. Commented Apr 28, 2011 at 19:26

Subspace is just a sort of a common sci-fi mumbo-jumbo. It's like asking what "elves" are. It's a different thing in different universes, and there's not a single definition for it.

The one thing most sci-fi settings have in common with respect to subspace is its intended usage; specifically, faster-than-light travel and/or communication.


Subspace and hyperspace are basic sci-fi jargon for an alternate dimension of the space-time continuum outside our perceivable 4D experience, in which the implications of Einstein's Theories of Relativity (namely that nothing can travel faster than light, and that while travelling close to the speed of light, time passes more quickly around you than your perception of it) are weakened or no longer apply. It's sci-fi hand-waving that is what the writers need it to be in order to allow the human race (and others) to travel faster than light and so visit other inhabited star systems in a convenient timeline.

The use of it is not universal in sci-fi. Arthur C. Clarke kept his stories primarily within the solar system and in general accordance with Einstein's theories; travel between Saturn's moon of Titan and Earth was about a three-week trip using a thrust engine based on an artificial singularity in Imperial Earth (basically the engine was efficient enough that the ship could be under power the entire trip, accelerating for half the journey and decelerating the rest). In 2001 and 2010 the ion-engine-powered Discovery vessels used cryogenic sleep to make the trip to Saturn's moon Iapetus possible (it was a journey of several months). The Host, loosely definable as sci-fi, talks of spaceships and interstellar sublight travel; travel between worlds colonized by the "souls" takes dozens, often hundreds, of years, mitigated by cryogenic sleep and the fact that souls have no natural life span of their own. Contrasting that, H. Beam Piper used hyperspace in his novels, but travel between Earth and most other colonized worlds was a few months' travel one-way. Lucas and Roddenberry obviously bought into FTL travel heavily for their universes, and travel between even rather far-flung worlds was a matter of hours or days.

Some of the newer universes have tied in with the ideas of string theory, some flavors of which indicate that we live in a universe of more than 4 dimensions, and our perception of only 4 is similar to a projection of a 3D object onto the flat plane of a piece of paper; it's subject to distortion based on the other dimensions that cannot be represented as such in our everyday perception. It then follows that if matter or energy can be moved along these additional dimensions instead of in the 3 normal spatial dimensions, messages or even ships can move along those dimensions and take advantage of their distorting effect on the 3 spacial dimensions, exceeding light speed as perceived by someone traveling sublight.


I believe subspace to be a sort of way of travelling through another dimension which is closely linked to the 3 we have. In the star trek world, I like to think of it as bordering on the verge of breaking the "time" barrier.

The faster you go the quicker you get there. If you can go fast enough to get there in 0 seconds, (instant travel, warp 10 tom paris hit that barrier), then anything above that is time travel, because you arrive before you left, and experience the same flow of time in both places.

I like the voyager episodes with that time ship, it did look like it had basic warp engines, and in theory, if they went over warp 10, they would travel back in time, and you'll need a lot of computing power to stablise speeds above warp 10, because your main problem would actually be slowing down enough to stop where you actually wanted! I'll stop now, because subspace makes for awesome stories, hence why it's in ST! :)

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