Faster-Than-Light Travel: Difference between revisions

In either case, explaining how people may travel from Earth to the edge of the Galaxy in less than an hour will generally involve equipping a [[Cool Starship]] with [[Applied Phlebotinum|some kind of "exotic" propulsion system]], which, approximately, holds the normal laws of physics in abatement. This is the Faster Than Light Drive. The exact mechanism varies, but more detailed works may explain [[Loophole Abuse|how the system avoids the lightspeed limitation]]. There are three broad favorites:

* "Warp" drives: [[Hand Wave|Ship waves hands very very fast and can thus go faster.]]

* "Jump" drives: [[Teleporters and Transporters|Ship disappears and reappears elsewhere.]]

** Technobabble; exploiting the curvature of spacetime in some way to instantly move a ship from one location to another. Functionally, a ship using one does not travel faster than light; instead, they alter the distance that has to be traveled, generally to about zero. Sometimes called "fold drives" (from the analogy of folding a piece of paper to make two distant points adjacent). As the range is rarely unlimited the ship typically moves in a series of "jumps", needing some time to recharge or recalibrate its engine between jumps, but the jump itself is generally instant making this technically the fastest method. Oddly enough this rarely uses [[Teleportation Tropes]] excepting perhaps [[Tele Frag]] as those are personal tropes. See also [[Our Wormholes Are Different]] for a variant.

* [[Isaac Asimov]]'s ''Robots''-''Empire''-''[[Foundation]]'' universe used "hyper-atomic" jump drives which, though one could theoretically use them to cross the galaxy instantaneously, could not be targeted accurately without first determining your exact position in space and then carefully calculating the relative trajectory of your destination from astronomical observations and manuals. As sophisticated computers did not exist in the Asimov universe until the later Foundation novels, this often had to be done by hand and plotting a single jump could take more than a day depending on how many gravity wells were around your locale. Long trips required several jumps, and to travel from one end of the galaxy to another required dozens of jumps and over two months time, in order to guarantee safe passage. "Blind jumps", where ships jump without a set course or a vaguely defined one, are known to occur in desperate circumstances, but one runs the risk of jumping too close to a star or planet, or merely jumping and being stuck in [[Subspace or Hyperspace|hyperspace]] forever.

** It should be noted that Asimov's hyperspace is one of the stranger examples is mainstream sci-fi. It's not so much a dimension as a "state" of existence. All speed and distance is nil in hyperspace, and the whole galaxy itself is nothing but a dimensionless point (hence the idea that one could cross it easily). Transit takes less than a second, and is described as a momentary, blink-and-you'll-miss-it feeling of weightlessness. Hyperspace accidents are repeatedly denounced as "unheard of", and everything becomes very [[Casual Interstellar Travel|casual]] after some proper computers are put in charge.

*** The stated reason that a positronic system could complete the calculation (while a duotronic system could not) is that the mind hosted by the positronic system allowed it to look past the deaths of the travelers and see that, once the ship emerged from hyperspace, they would come back to life. It may also have observed that it was possible to make the transit instantaneous, which would eliminate the problem entirely.

** The first time a ''proper'' navigational computer is used to jump a ship to a destination, it plots a course involving some 29 jumps in a few seconds (something that a human would have taken days to do) with zero errors. The captain, Golan Trevize, is distrustful of the machine and orders it to make only the first jump, then takes a whole day to verify their co-ordinates (making calculation errors of his own in the process). When he orders the next jumps to be made, the effect as seen on the viewscreen is something akin to a quick slideshow of starscapes, each frame corresponding to a pause between jumps. In the end, only 28 jumps are made (in 30 minutes, as opposed to a few months), since the computer had optimized their course after jump 15. Everyone is rightly impressed with this.