Science-fiction has used wormhole travel, hyperdrive, teleportation, even sub-FTL flight combined with time travel o get characters there and back again. Even hard science-fiction writer Larry Niven has used faster-than-light drives, and he admits that they were solely a plot device.

Are there any FTL systems in science-fiction that are possible from the point of view of modern-day physics?

(Inspired by this question.)

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    wouldn't this be more appropriate over at Physics.SE? although, it's a nice question
    – HorusKol
    Nov 30, 2012 at 5:51

6 Answers 6


FTL travel is (strictly speaking), not allowed by physics. However, a warp drive could be constructed that allows the illusion of traveling at FTL speeds by compressing space in front of a ship, and expanding it in back. This would allow a ship to go from one place to another without breaking any laws, since the ship travels at sub-light speeds, yet still move from one place to another more quickly than a traditional method at sub-light speeds. This is what the Enterprise (and any other ships in ST) are supposed to use.

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    This. Also wormholes. And there are some quantum effects that probably won't, but just might be scaled up. Jan 30, 2011 at 3:14
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    True, I can't believe I forgot about that. But I suppose that a wormhole doesn't fall under FTL tech, it's more of a gate. Jan 30, 2011 at 5:32
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    @Noldorin They are purely hypothetical. All FTL is purely hypothetical. A century ago wireless information transmission was purely hypothetical. What's your point? Also, whether or not they are "accepted" or "contentious" is rather beside the point. There are a lot of things in physics that are "contentious". That's what happens in a science that is half experimental and half theoretical math. Jan 30, 2011 at 16:12
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    @Daniel: I'm no fully-fledged physicist either, but it's not safe to assume the average user here understands physics well (unlike Physics SE). Anyway, let's not get at each other's throats over nothing. :) I take your point; there have indeed been theoretical papers written on the wormholes and whatnot. You seem to know they're highly contentious as far non-crackpot physics go, so I'll leave my point there. They're interesting things, even if they do depend on conjectured extensions to existing theory.
    – Noldorin
    Jan 30, 2011 at 22:14
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    Just for the record: wireless telegraphy is older than a century: en.wikipedia.org/wiki/Wireless_telegraphy Nov 10, 2011 at 13:22

There are at least 3 systems which are at this time somewhat plausible, although currently there isn't nearly enough knowledge to try any of them.

  1. The ansible system used in Orson Scott Card's Ender's series for instantaneous communication is at least plausible.
  2. The general notation of a wormhole has some possibilities, although as previously mentioned, it would take alot of energy.
  3. Any drive that mentions folding space might be possible.

These are the only 3 I know anything about, and they are all seemingly unlikely, so...

  • How does the ansible in Card's books work? Jan 16, 2011 at 4:45
  • I think it uses the quantum entanglement principal, which seems to transmit information faster than light right now, although it's not completely proven yet, so... Jan 16, 2011 at 14:02
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    Actually the opposite is proven. You don't transmit information faster than light with quantum entanglement. Relativity is not broken.
    – Dr G
    Jan 17, 2011 at 22:40
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    The Alcubierre drive, which describes a Star Trek-esque "warp bubble" allowing FTL travel while not being subject to Einsteinian special relativity, does at this point seem theoretically plausible. We just don't yet have energy-producing technologies of sufficient capacity to transport "real" amounts of matter (like a 200,000 metric ton Constitution-class starship).
    – KeithS
    Nov 30, 2011 at 20:41
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    @DrG : Really? Apparently you're right since a lot of people have voted up your statemement, but I thought that information travel via quantum entanglement did seem to transmit information ftl. Is there a source for this I can use to reeducate myself? (I'll hit Wikipedia first, of course...but, beyond that?)
    – Beska
    Feb 10, 2012 at 17:50

NASA is supposedly testing some elements of the Alcubierre Warp Drive at present. This renders it the most plausible, in that actual scientists are working on the practical implementation.
NASA: Warp Drive When?
Techland.time.com NASA Actually Working on FTL warp drive

Following this, various kinds of Wormholes are fairly viable.

Hyperspace drives (Drives thrusting a ship into an alternate, parallel universe with either a different value for C or non-1:1 correlation to our 4-D spacetime) are dimly plausible.

Space folding is improbable, but readily explained and not utterly implausible.

N-space FTL not involving compression/expansion of spacetime is almost totally implausible.

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    should have way more upvotes imho
    – Quonux
    Jul 28, 2013 at 1:10

A hyperspacial drive could be possible, as we don't know whether or not any sort of hyperspace exists...

Edit: If there exists a parallel universe, or extension of this universe, in which either the light-speed limit does not apply, or is higher, that is a "hyperspace" in which practical FTL (in relation to this universe) is possible. Another possibility is the hyperspace of Asimov's Foundation series, in which hyperspace is a single point that can be jumped through to any point in the universe. However, the existence of any such space is currently unprovable, as far as I know.

  • +1 "We have no evidence that this is possible" is definitely better than "everything we know says this is impossible" (like with other FTL travel). Aug 15, 2011 at 17:46

I suppose if one of the theories (such as string theory), which has a universe with several unseen dimensions, then you open up some possibilities. Usually the argument goes from 2D to 3D, with the 2-D universe being a surface like a rolled up piece of paper, if you can travel in the third (forbidden) dimension you can drill through to a distant part of the paper. So you could imagine if you could exploit a fourth (or higher) dimension, that all bets are off.

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    String theory involves dimensions that are "curled up", which sounds useless for movement, unfortunately. Jan 30, 2011 at 4:44
  • @neilfein: Yes, they're supposedly too tiny for us to measure/detect at present, but this is sci-fi, so perhaps there's a way. I think it would be more likely that the string theory dimensions would be equivalent to sci-fi's "subspace" and perhaps we could send signals or particles through subspace and they are able to travel faster than light there? (Or perhaps enormous energies could be extracted from there? I believe that the reason these extra dimensions are proposed is to "dilute" gravity, so perhaps this gravity energy could be harvested from there?)
    – Wayne
    May 16, 2011 at 17:26
  • There is nothing in string theory to say that there are not more than 4 physical dememsions in addition to the 7 "Curled" dimensions within a string. one could simply slip along an extra dimension and simply "Sidestep" Conventional laws. Nov 30, 2012 at 2:46


Burkhard Heim (February 9, 1925 – January 14, 2001) was a German theoretical physicist. He devoted a large portion of his life to the pursuit of his unified field theory, Heim theory.[1] One of his childhood ambitions was to develop a method of space travel, which contributed to his motivation to find such a theory.[2]

In the 1950s (Yep, before Star Trek), Heim proposed what effectively IS a warp drive, involving intense magnetic fields. Unfortunately, we are currently unable to test those theories.

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