How do you like your FTL?

[Cheryl]

Do you need it explained, or is handwavium fine?

Do you think communication should be just as fast? Or maybe it's only communication that can beat the limit?

Should it be instant? Should it be degrees of warp?

Should it be a portal, a wormhole, your ship's own space/time bubble, or something else?

What books do you think have handled this the very best of all, and why & how?

(Yes, I did search for previous topics on the subject and while some seemed to touch on these questions, none suited me.)

[Don]

wormhole

[Joon]

I don't know that I really have a preference, as long as the story uses whatever limitations it gives itself in a compelling way.

If it's in the story, I like to know how it came about (anecdotally), but I absolutely don't need it to be based on real science. Even if it's just ripped off from an abandoned alien ship or whatever. I don't need to get in the political or technological weeds of the full development, but if FTL factors into a story, it adds color to talk a bit about how they have FTL in the first place.

Both of Jack McDevitt's long running series have FTL, and unless memory fails me (and it might), I believe they're handled similarly in both; it's not instant, there's a good amount of "sub-space" travel, so the trip is sped up considerably but depending on the distance could still take days or weeks. Furthermore, you don't arrive right at your target; because it's not an exact science you can only really approximate your destination, so each FTL trip will get you in the neighborhood, but will always be followed by a lengthy real-space trip to actually get to your destination. Can't have you coming out of FTL in the middle of a sun. I like that. It adds some believable inconvenience to the process, and of course it gives the characters time to putter.

And over the course of those series, there are complications with FTL, or discussions about how it would go wrong in the early days, how it had improved, etc. In one of the series, there's actually a series-spanning mystery about a major problem with FTL that has caused ships to go missing entirely.

And again, none of it is based on reality. He never even tries to explain how it works, and in fact in one of the series the narrator flat out admits she wouldn't even begin to understand it herself. Which is how I prefer it, I think. Keeps the story accessible.


And though it's been a few years since I read it (I'm reading it again soon), Becky Chambers' first book The Long Way to a Small Angry Planet is about ships that travel the galaxy basically building wormholes; the idea being that before you can have the shortcut, someone has to go the long way first. Which is another interesting way of looking at how FTL might start in a way that doesn't bury the story in science.

[Phillip]

I'm good with any method, but hand waving is always preferred.

[[deleted user]]

On the other hand, some particular authors' handwaving is definitely not as good, satisfactory or plausible as other authors' handwaving. One Sci-fi author I gave up on (for many reasons on top of his FTL system) was David Weber. His described system of space resonance (?) was to say the least opaque and not very obvious. He also happened to take pages and pages of repetitive descriptions and explanations which only lost me completely, along with many other readers (if I go by reviews of his books). Another system of space travel was downright laughable by its crudeness and vulgarity. The French sci-fi author who 'invented' it decades ago, when leftist sci-fi was in fashion in France, made his people travel by having sex while under the effects of a super drug! I doubt that I will ever read something more ridiculous thand that one!

[John]

I'm a fan of the David Weber school of FTL -- hyperspace travel at many times light speed (but not instantaneous -- travel between stars takes days or even weeks), with the additional provision that you can't enter or leave hyperspace anywhere close to a star or planet, so you also have to spend significant time traveling in "normal" space to reach the "hyper limit" of a given system. This works especially well for military-themed SF (like Weber's Honor Harrington series) because it means space warfare -- which takes place mostly near stars and planets -- must obey the ordinary laws of physics.
There's also the provision that communication through hyperspace hasn't been worked out yet -- so the only way to get a message from one star system to another is to send it by ship. This puts communication back to the days of wooden sailing ships on Earth -- which becomes a factor in Weber's novels. Of course, Weber himself admits that he was inspired by C. S. Forester, and that Honor Harrington is really a futuristic, gender-flipped analog of Horatio Hornblower.
For the record, Weber does -- over the course of many novels -- attempt to explain the "science" of his FTL system, so he's not doing a lot of handwavium.

[Midiain]

If an author is going to talk about FTL then they need to make the mechanics of is at least somewhat plausible, but most of the time I'd rather it wasn't even mentioned. Just accept that it's there and it works.

I like when travel takes some time whether it's days, weeks, or even months depending on how far they have to go. It gives some feeling for the vastness of space and the almost incomprehensible distance between worlds that instant travel doesn't. I also like when things don't come too easily for the characters and there is some cost or difficultly in accomplishing tasks. I prefer that they can't communicate during FTL. Again, don't make it too easy.

C.J. Cherryh handles it well. I think it was explained more in her Chanur series, maybe some of the Foreigner series too, but it's fairly consistent throughout her Union-Alliance universe that encompasses most of her SF in some way. All of her space-faring civilizations have some version of the same thing. I don't remember the specifics but it uses gravity fields to pull the ship between planets along the border between real space and hyperspace. Like Weber, it can't be done too close to "gravity wells" and takes time to move in their vicinity.

Certain species can do it better, like changing trajectory mid jump, but only because they're aliens and their brains work differently and their minds and bodies can handle strains that humans can't. She creates truly alien, inhuman, beings masterfully.

[Micah]

To all the questions in the OP: Yes.

All of it.

Depends on the book. And actually I like to see as many different setups as possible in different books because the choices the author makes can drastically change the world building.

Handwavium vs spelled out depends on the book, too, but my general preference is that if the technology has a plot importance then more detail is probably necessary. If it really has no other purpose than to make the world possible (for example, you really cannot have a galactic empire without at least FTL travel, but the TYPE of FTL or how it's done technically is not necessarily of any plot importance), then glossing over it with handwavium is the way to go.

But the choices you make can have interesting consequences. For example, if you allow FTL travel but not communication, then you have a world where coordinating troop movements, diplomacy, commerce, interpersonal communication, etc. can be muddled or restricted leading to points of tension and conflict in the story. If you've got FTL communication but not travel, then you've introduced a very different dynamic that would lead to very different story lines.

Exploring those differences can be fascinating.

[Micah]

As for books that have handled it well, there are just so many.

Take a look at Dan Simmons's first two novels in the Hyperion Cantos for example. They use instantaneous ("farcaster") portals handled all very handwavium. At least at first. They seem a nice contrivance to allow the characters and plot to move throughout the worlds connected by the farcaster portals, and are incorporated in some awesome ideas (like houses where every room is on a different world, connected by farcaster portal "doors"). But as the first two books go on, the farcasters true nature is revealed and they become a central element in the conflict that resolves in the second book (The Fall of Hyperion).

Then, in the second two books (Endymion and The Rise of Endymion), set some 274 years after the first two books, farcasters are no more and the technology to travel between worlds is all ship-based and imposes "time debt" (dilation) effects on those who travel that way. The technology is not really discussed, IIRC, but the effects of that way of travel are.

[Micah]

Peter F. Hamilton also used FTL that was affected by gravitational forces near stars and planets in his Night's Dawn Trilogy (The Reality Dysfunction, The Neutronium Alchemist, and The Naked God). However, cleverly, ships near moons or planetary bodies would move to one of the five Lagrange Points near co-orbiting bodies (Sun/Planet, Planet/Moon, etc.) in order to make there jumps. These are points in a two-body system where the gravitational pull of the two bodies cancel each other out. These are real and are used today as ideal locations to park satellites and space telescopes.

The actual method of FTL, I don't recall was ever really mentioned. It wasn't necessary. But having ships in combat, realizing they were about to get zonked into their component molecules, run for a Lagrange point was pretty cool.

[Micah]

And of course I must give kudos to Frank Herbert for his folding space idea: travelling without moving. Very metaphysical and nonsensical but still cool. Man, that spice stuff was good for everything!

[Richard]

I'm a big fan of the Alcubierre drive. What a shame that it's a purely theoretical idea and no-one has the slightest idea how to build one! The idea is that you form a space-time bubble around yourself so that you are in a distorted part of the big universe.
You can then apparently move to any point in the universe without having any speed at all. A bit like a portable wormhole.
One problem I've thought about is how you would navigate. It may have to be a simple "aim and fire" while you were still in the big universe.
A poor shot could end up mega light years off course.

[Joon]

Richard wrote: "I'm a big fan of the Alcubierre drive. What a shame that it's a purely theoretical idea and no-one has the slightest idea how to build one! The idea is that you form a space-time bubble around your..."

The book I'm reading now (Ancestral Night) utilizes that very thing, and gets into the logistics of relative bubble size (for example, how a small vessel might tug a large one), direction, what happens to debris within the bubble upon exiting, etc.

I hadn't actually read much about it before this and it is pretty fascinating.

[Allison, Fairy Mod-mother]

I like cool ideas and think internal consistency is more important than theoretical possibility. I do like nods to handling real world problems though. Like, famously, Star Trek introduced the Heisenberg compensator to handle the problems the Heisenberg Uncertainty Principle would introduce to beam technology

Or, like when a book mentions how shielding is important to handle the impact of space dust on FTL vehicles, I love little nods like that to reality, even if we're still dealing with what is essentially magic.

[Bobby]

Allison, that's pretty much exactly how I feel. I don't mind hand waving at all, but I still like some effort to be put into it so it feels like something that is real in the world we are experiencing. I especially like when there are limits and challenges to it, so it isn't too good to be true.

[Leticia]

Wormholes, like in Stargate Atlantis are always fun, tough Enterprise Warp is also interesting as it can break and leave a ship lost in an unknown galaxy.

[Ian]

Bobby wrote: "Allison, that's pretty much exactly how I feel. I don't mind hand waving at all, but I still like some effort to be put into it so it feels like something that is real in the world we are experienc..."

Some early examples of interstellar travel in the science fiction magazines are interesting. E.E. ("Doc") Smith* never did explain the FTL velocities required in his early "Skylark" novels (just that the propulsion was provided by the atomic disintegration of metals, originally copper, I think), but in his later "Lensman" stories (originally beginning with "Galactic Patrol') he introduced the concept of the "inertialess drive."

This was pretty pure handwavium. The "Bergenholm Drive" somehow temporarily cancelled inertia, allowing ships to accelerate immediately to whatever speed their power allowed -- without mentioning complicating relativity issues.

However, Smith built in limitations, such as problems with what happened when the "intrinsic" inertia was restored in another frame of reference, and the need to power heavy force fields to deal with space dust encountered at FTL speeds.

Jack Williamson's "Legion of Space" stories had a somewhat similar device, the geodyne, which somehow allowed ships to travel along geodesic curves, instead of in "normal" space, arriving at destinations much more quickly by way of a shortcut in space. This is a likely ancestor of all later "warp drives."

But, as L. Sprague de Camp noted in his "Science Fiction Handbook" in the 1950s, Williamson got his geometry wrong -- geodesic curves would make the journey longer, not shorter. However Williamson postulated that even with this (dubious) advantage, interstellar journeys were long and arduous.

So far as I can recall, Edmond Hamilton's "Interstellar Patrol" series of short works never did explain the means of interstellar travel (like Smith's "Skylark of Space"), but was memorable for introducing a community of worlds numbering diverse intelligent species -- plus presenting a precursor to Williamson's Legion of Space, and, more closely, Smith's multi-species Galactic Patrol.

By the way, Wiliamson's "Legion of Space" stories also featured a sort of ultimate secret weapon, known only as AKKA (a reference to a story by A. Merritt). It was capable of eliminating anything from, say, a small pebble, to a whole planet, leaving behind no dangerous residue. Part of the "device" was mental, which made it hard to steal or copy, but it was supposed to be science, and not magic, and duplicating it was eventually accomplished.

One wonders whether, if US policy makers had read the story, they would have understood that the only real secret of the Atomic Bomb was that there was one, and it worked.

There is a story, though, that Williamson was later told by someone who worked on the Manhattan Project that she began thinking about ultimate weapons after reading "The Legion of Space."

*Smith had a PhD in chemistry -- not physics -- and for a while was the only science fiction writer known to have a doctorate. However, "John Taine," who published science fiction in general fiction magazines, instead of the SF pulps, was actually Dr. Eric Temple Bell, whose degree was in mathematics. Naturally, most of his fiction was about biology.....

[Ryan]

I like the inclusion of FTL or Near Light Speed travel in Sci-fi but the level of detail I enjoy really depends on the book and how it’s delivered.

For FTL Travel I think it depends on the character describing it, if the character isn’t someone I would expect to have a working understanding of FTL travel I prefer it to be hand wavy but with some theories maybe rumors. If it’s a scientist or a high well engineer that deals with this stuff I’d expect more detail but never the whole thing. Tbh I’d expect only a handful of humans at any given time to ever understand it fully.

But I love the inclusion of FTL or near light speed travel/communication when used as a story mechanic.

Speaker For the Dead, the instantaneous transfer of communication uses unexplained alien tech but is the foundation of human communication and its expansion. The near light speed travel is a cool contrast, utilizing relativity it may feel like FTL for The Speaker but large swaths of time is lost and you feel that lose when reintroduced to society.

Old Man’s War, is where I found I liked the hand wavy answer from those who don’t understand because Harry tries to very vaguely describe how it might work with his higher education being in physics but also explaining there probably only a handful of people who know it all.

Interdependency: The Flownis just such an important aspect of the story and is the foundation of how society expanded.

[Don]

wormholes or extradimensional

[Adrian]

If you want to visit exotic places far away (especially those potentially supportive of human life) then you have to have a means of getting there. I'm sure there'd be stories about multi-generational journeys - I've not read one but I'd be amazed if they didn't exist - but for the most part we get stories that can go from place to place quickly and, for me, I don't really mind how it happens as long as it doesn't jolt me out of the story through silliness (like that bonking drive described above at #5).

One of my favourites will raise a bit of an eyebrow perhaps. The drive described in Starman Jones (Heinlein) was about navigating from wormhole to wormhole using astrogation books (plus pencil and paper) akin to trigonometry tables. This was a book written in 1954 - long before modern computers - and the tech was key to the story.

Really well written and quite gripping in places. (Although a bit kiddyish for my taste these days.)

[Sharon]

I like some reference to the means of FTL and the constraints it imposes on characters, but it does not always need to be spelled out in detail. When the FTL technology affects the plot, then I want to know more about it. I prefer to see explanations play out in the story rather than a brain dump on technology.

As others have said, I would expect some characters to understand the FTL theory and tech, while others just come along for the ride, knowing it works. As a reader, I'm also perfectly happy to come along for the ride, accepting that it works. After all, that is the suspension-of-disbelief we grant to fiction. And to parts of reality, if you think about it.