Second this recommendation. I started the final book today and it is excellent.
Edit: oops, wrong series. The third book of MacLeod’s new trilogy released this week, Beyond the Light Horizon from the Lightspeed Trilogy. Travel is superluminal in this series.
Wikipedia entries are rather brief. Web search found some "reviews" from which I gather the story is mostly about living on a distant planet, not travel. Please mark spoilers if consider needed but provide more details about travel and what "%" of books it is.
OK, it's been over 20 years, but I'll use spoilers.
**Cosmonaut Keep** >!After about third to half way, the lightspeed drive is introduced. By the end of the book, our heroes are far from home in time and space.!<
**Darklight** >!Years from the end of **Engines of Light** millennia from Earth. The squids hold the secret to navigating with lightspeed drive and they aren't sharing, but aren't stopping the humans from working it out. By the end the drive is seeing a fair amount of use. !<
**Engines of Light** >!Most use of the drive of the three. Drives become widespread as well as the navigation and things start happening with it. It becomes clear that the drive is weird.!<
I read it for the first time last year; I get what you're saying, but it does get better, and the conflicts of the story are hardly character driven, and focus on the ship's situation with respect to a series of changing destinations. I found it to be really... not mind blowing, that's not quite it, but audacious in scope.
I really like it, I’ve read it a few times
Tbf the technical descriptions and ideas interest me more than the interpersonal relationships of the characters but I would say yes it does get better and is definitely worth giving a bit more time
It’s only ~200 pages at the end of the day and once it gets going I find it a real page-turner
That's a fairly narrow niche, as for all practical purposes literal light speed travel is basically as impossible as FTL travel. It is a) as impossible to achieve through any conventional means as FTL, and b) would be literally impossible to control if you could achieve it, as you would experience literally 0 time, and thus the moment you reached light speed you would immediately reach the end of your own existence in the universe, whatever that may be. And if these issues are waved away via something like hyperspace, then that is essentially still FTL, just with an odd speed constraint.
I've never personally heard of a sci-fi book imposing a literal exactly-c light speed limit on travel, usually they either hand-wave some reason for FTL to exist, or just allow for travel at 0.99999999999999999999... c, as that is essentially light speed, without all the universe-breaking implications that would come along with an object moving at 1c. It is an interesting idea though, it makes me want to check out *Neptune's Children* and see how it is treated there.
The best I can think of is stories where you can travel *as light*, ie. You ditch your physical body, transmit yourself as information at light speed, then become re-incorporated at your destination.
Some recent theoretical research suggests this is actually a possibility: [https://phys.org/news/2024-05-subluminal-warp.html](https://phys.org/news/2024-05-subluminal-warp.html)
> The team blends both new and traditional physics techniques based on gravity to describe the creation of a warp bubble around an object, allowing it to travel at speeds that are far beyond those that have been proposed to date—**though, not at or above the speed of light**.
This, if true, would be a step towards a reactionless drive, one that does not need to carry around mass to throw out the back to accelerate, but it would not allow you to travel at light speed, merely approach it more rapidly.
Yes but the comment was posted in response to someone correctly stating that literal light speed is, FAPP, just as impossible as FTL. The claim then was that it is “actually a possibility”, citing a paper that literally excludes that possibility. I’d say it’s totally fair to call this out as (at the least) misleading.
I thought it was saying that OP's request for "roughly at the speed of light" was impossible (a theme of several comments). But I missed that part was an edit.
An example is the *Astropolis* trilogy by Sean Williams. There's no FTL, so communications are by a grid of high-power lasers transmitting between star systems with the accordant delays. People can "travel" between systems by being scanned at a molecular level and then the data is transmitted to the destination, where you are rebuilt. The author didn't ignore the philosophical "are you even the same person" question, but many characters simply prefer not to think about it.
I would imagine you're thinking of "Riding the Crocodile" (with the caveat that they have to send a receiver to their destination at subluminal speeds, or otherwise have one waiting there, if they want to travel there at light speed).
The infinitely fueled rockets are from the Revelation Space universe. In the House of Suns universe, starships move by "parametric drives" which aren't explained in detail, but appear to be reactionless. There are other examples of Anti-gravity in the book as well. I wish Reynolds would write more books set in this universe.
No, they use both in House of Suns. They use standard reaction drives for local travel. The book references "parametric engines" for relativistic travel. It doesn't go into detail but based on the terminology I would guess it has to do with gravity manipulation or somehow otherwise manipulating (oscillating/vibrating, something to do with parametric resonance) spacetime.
There's an entire sequence in the book wherein an interstellar car chase occurs at significant fractions of *c*.
What do you mean? high velocity but less than 1 c or speed exactly =c? Because if you mean exactly c that is as impossible as FTL, the time dilation equations would be fucked up for sure...And why, what would you get from speed=1 c rather than 0.9999c? (edit, answering my own question, with speed precisely equal to to 1c what you get is division by zero, but that is the thing and if you want fiction about division by zero made REAL, that is hard to pull off in any serious way...)
I'm curious what meaningful story differences you expect between "warp drive/hyper drive that *can't* go faster than 1c" and "super fast conventional drive that can go arbitrarily close to 1c," that wouldn't also exist between "warp drive/hyper drive that *can* go faster than 1c" and "super fast conventional drive that can go arbitrarily close to 1c."
Basically, what would putting the 1c limit on the warp drive change about the story other than the time it takes to get places?
Travel limited to C can make journeys between stars take years rather than centuries. Macleod's "Engines of light," has this as a major world building point.
I still do not understand. Ok, so we break the laws and can travel at precisely the speed of light? But if we break those laws, warp drive, hyper drive and all (Wormholes!) why stick to travelling at PRECISELY the speed of light, why not go above it? In relation to known physics, it's as possible/impossible speed=c or speed>c. Same thing. Edit - actually I think the concept of speed precisely equal to c is worse than speed above c. Mathematically we can handle imaginary numbers way better than division by zero.
Also the concept of speed is itself measurable and will have an error margin. And space is not a perfect vacuum and even photons interact with particles, and a massive ship would have particle interactions with solitary atoms on the path it travels. I am not sure we can talk of a physical object as being feasibly travelling through space as photon (or neutrino) would...
Charles Stross’ early novel Scratch Monkey, available free from his web site. People travel as radio at a speed determined by how much error correction you want…
There is a number of stories in Larry Niven's "known space" universe which use non-FTL ships. In this universe, humans bought FTL technology from aliens during a war with another alien species; there is a number of novels and short stories from before humans got FTL. Some novels (by no means all): "A Gift from Earth", "World of Ptavvs", "Protector".
In this universe, there are Bussard ramships (using a magnetic field to gather interstellar hydrogen for fuel) and also slowships (1/3 lightspeed, used for colonization, because early ramships couldn't carry living beings; too much radiation). In general, Niven's stories pay at least some attention to science.
Can't remember, but it was expensive (t was just the background of some stories, never the main point).
In another part of the Known Space stories, the Puppeteers (which are much more technically advanced than humans) bought from the Outsiders a reactionless drive to move their worlds; they are still paying for it.
In another story, the protagonists meet an Outside ship (Outsiders don't use hyperspace); the ship's drive brought the ship from near-lightspeed to zero in moments. It's also mentioned that this drive was for sale but nobody could afford it.
Outsider technology is advanced but very expensive.
The whole Outsider stuff is just background and not explained in detail. Generally the Outsiders are a species which doesn't have a lot of interaction with humans; they live in interstellar vacuum at near absolute zero, they trade in information. They have nearly unlimited credit in human banks, so I assume they use human money for interactions with humans.
It's mentioned (I believe in "Ringworld") that the Outsiders follow "starseeds" (a non-sentient vacuum animal which uses lightsail to navigate) but nobody knows why (it's mentioned that Outsiders will answer personal questions, but at a price which nobody can afford). The puppeteers used a tool which changes stars' radiation to lure a startseed near human space and the Outsiders which followed it sold the FTL drive to humans, which allowed them to win their war against the alien "Kzin" (described as sentient, aggressive and physically similar to tigers).
Known Space is an interesting, pretty consistent, future history; there's a lot of background information fleshing it out. The Outsiders are kind of bit-players, Kzin and Puppeteers are major players.
Manifold Space (Steven Baxter) features light-speed portals distributed throughout the galaxy. To the traveler they move instantly, but to outside observers the move at lights-speed from origin to destination.
Curvature propulsion in Three Body Problem/Death's End get close to light speed. They create a gravity well in front of the ship, so that you can essentially accelerate forever. But they only pop up pretty late in the books and aren't seeing much actual use for travel in the end. They also have the nasty side effect in that they mess up the space time in the process.
In Baxters *Proxima*/*Ultima* duology there is a transport system like that.
There is also a comic series that was from France I think that had exactly that but I can't recall the name. There human scientists invent an engine that transports the ship at lightspeed to its destination and they meet aliens who also only travel at the speed of light (though their engine is a lot less dangerous and more efficient). During the course of the comic characters make light speed jumps several times and always lose the appropriate amount of time relative to people that stay on Earth.
The only stories I know of that do actual "you are a photon" style, precisely-light-speed travel are MacLeod's "Engines of Light" trilogy and two short stories by Niven that I haven't read in so long that I can barely remember them.
Three body problem has this at the end of the trilogy. They’re able to change light speed around the ship by a lot of stuff I don’t really remember. Basically humans can make it to like 75-99% of light speed by they’re work around and it also ends up having consequences
FYI, warp 1 on Star Trek is light speed, but we rarely see anyone actually use it when faster speeds are available, although there’s a scene in DIS that shows the most accurate warp jump in the entire franchise in terms of speed, distance, and time
Every Le Guin novel and short story set in her Hainish universe and they are incredible. She thought the primary reason FTL existed in most sci fi stories was for there to be intergalactic space war, which didn't really interest her.
The Enderverse novels use near light speed travel, and deals with the consequences of time dilation, with some characters living for hundreds of years due to frequent space travel. At least until the later novels when it gets really woowoo mystical and they can >!teleport anywhere in the universe just by thinking about it.!<
David Weber wrote Honor Harrington, and they do have hyperspace travel.
The only Ringo books I’ve read was the Troy Rising series, and that one uses gates for travel
Ken MacLeod's **Engines of Light** trilogy. Travel is light speed and navigation is a pain.
Second this recommendation. I started the final book today and it is excellent. Edit: oops, wrong series. The third book of MacLeod’s new trilogy released this week, Beyond the Light Horizon from the Lightspeed Trilogy. Travel is superluminal in this series.
Yours oops is *equivocal*. Is it about seconding, superluminality or Engines or Lightspeed?
The Engines of Light trilogy is excellent. I misread the post and thought it was recommending the Lightspeed trilogy.
Wikipedia entries are rather brief. Web search found some "reviews" from which I gather the story is mostly about living on a distant planet, not travel. Please mark spoilers if consider needed but provide more details about travel and what "%" of books it is.
OK, it's been over 20 years, but I'll use spoilers. **Cosmonaut Keep** >!After about third to half way, the lightspeed drive is introduced. By the end of the book, our heroes are far from home in time and space.!< **Darklight** >!Years from the end of **Engines of Light** millennia from Earth. The squids hold the secret to navigating with lightspeed drive and they aren't sharing, but aren't stopping the humans from working it out. By the end the drive is seeing a fair amount of use. !< **Engines of Light** >!Most use of the drive of the three. Drives become widespread as well as the navigation and things start happening with it. It becomes clear that the drive is weird.!<
Awesome I'll add him to the list.
Tau Zero maybe?
Does Tau Zero get better? I started it but gave up since the first chapter is all the charicters acting like horny teenagers.
I read it for the first time last year; I get what you're saying, but it does get better, and the conflicts of the story are hardly character driven, and focus on the ship's situation with respect to a series of changing destinations. I found it to be really... not mind blowing, that's not quite it, but audacious in scope.
I really like it, I’ve read it a few times Tbf the technical descriptions and ideas interest me more than the interpersonal relationships of the characters but I would say yes it does get better and is definitely worth giving a bit more time It’s only ~200 pages at the end of the day and once it gets going I find it a real page-turner
Yeah, but at 200 pages, it's one of the longest books ever written, time-span wise.
That's a fairly narrow niche, as for all practical purposes literal light speed travel is basically as impossible as FTL travel. It is a) as impossible to achieve through any conventional means as FTL, and b) would be literally impossible to control if you could achieve it, as you would experience literally 0 time, and thus the moment you reached light speed you would immediately reach the end of your own existence in the universe, whatever that may be. And if these issues are waved away via something like hyperspace, then that is essentially still FTL, just with an odd speed constraint. I've never personally heard of a sci-fi book imposing a literal exactly-c light speed limit on travel, usually they either hand-wave some reason for FTL to exist, or just allow for travel at 0.99999999999999999999... c, as that is essentially light speed, without all the universe-breaking implications that would come along with an object moving at 1c. It is an interesting idea though, it makes me want to check out *Neptune's Children* and see how it is treated there. The best I can think of is stories where you can travel *as light*, ie. You ditch your physical body, transmit yourself as information at light speed, then become re-incorporated at your destination.
Accelerandos final chapters goes here
Some recent theoretical research suggests this is actually a possibility: [https://phys.org/news/2024-05-subluminal-warp.html](https://phys.org/news/2024-05-subluminal-warp.html)
> The team blends both new and traditional physics techniques based on gravity to describe the creation of a warp bubble around an object, allowing it to travel at speeds that are far beyond those that have been proposed to date—**though, not at or above the speed of light**. This, if true, would be a step towards a reactionless drive, one that does not need to carry around mass to throw out the back to accelerate, but it would not allow you to travel at light speed, merely approach it more rapidly.
I think that's consistent with OP's request--getting you close to the speed of light.
Yes but the comment was posted in response to someone correctly stating that literal light speed is, FAPP, just as impossible as FTL. The claim then was that it is “actually a possibility”, citing a paper that literally excludes that possibility. I’d say it’s totally fair to call this out as (at the least) misleading.
I thought it was saying that OP's request for "roughly at the speed of light" was impossible (a theme of several comments). But I missed that part was an edit.
Near FTL in Project Hail Mary.
AMAZE AMAZE AMAZE
FIst my bump!
PHM is great!
Most of Ursula Le Guin’s Hainish novels are NAFAL travel.
When I first read her books, it took me a long time to realize NAFAL stood for "Nearly As Fast As Light!" (No Google in those days.)
Anywhere people travel as information without FTL communications. I think there was a Greg Egan story but can’t remember the title.
*Schild's Ladder*, but it really wasn't the focus.
It’s amazing how he has some mind-blowing concept just thrown out there every few pages that others would turn into a five-part series.
I read it years ago and I feel I should read it again - I think I would have some new insights now. Almost my favourite Egan book.
An example is the *Astropolis* trilogy by Sean Williams. There's no FTL, so communications are by a grid of high-power lasers transmitting between star systems with the accordant delays. People can "travel" between systems by being scanned at a molecular level and then the data is transmitted to the destination, where you are rebuilt. The author didn't ignore the philosophical "are you even the same person" question, but many characters simply prefer not to think about it.
I would imagine you're thinking of "Riding the Crocodile" (with the caveat that they have to send a receiver to their destination at subluminal speeds, or otherwise have one waiting there, if they want to travel there at light speed).
Alastair Reynolds - House of Suns?
They just use rockets that are able to run for a very long time.
The infinitely fueled rockets are from the Revelation Space universe. In the House of Suns universe, starships move by "parametric drives" which aren't explained in detail, but appear to be reactionless. There are other examples of Anti-gravity in the book as well. I wish Reynolds would write more books set in this universe.
A sequel is apparently in the works
Did he make some announcement about that? I loved that book.
The light huggers in his Revelation Space series do this - travel at very near lightspeed. Not quite the same as House of Suns.
Fair enough!
No, they use both in House of Suns. They use standard reaction drives for local travel. The book references "parametric engines" for relativistic travel. It doesn't go into detail but based on the terminology I would guess it has to do with gravity manipulation or somehow otherwise manipulating (oscillating/vibrating, something to do with parametric resonance) spacetime. There's an entire sequence in the book wherein an interstellar car chase occurs at significant fractions of *c*.
What do you mean? high velocity but less than 1 c or speed exactly =c? Because if you mean exactly c that is as impossible as FTL, the time dilation equations would be fucked up for sure...And why, what would you get from speed=1 c rather than 0.9999c? (edit, answering my own question, with speed precisely equal to to 1c what you get is division by zero, but that is the thing and if you want fiction about division by zero made REAL, that is hard to pull off in any serious way...)
I specifically said travel using a warp drive/hyper drive/etc so no I am not talking about just moving through real space super fast.
I'm curious what meaningful story differences you expect between "warp drive/hyper drive that *can't* go faster than 1c" and "super fast conventional drive that can go arbitrarily close to 1c," that wouldn't also exist between "warp drive/hyper drive that *can* go faster than 1c" and "super fast conventional drive that can go arbitrarily close to 1c." Basically, what would putting the 1c limit on the warp drive change about the story other than the time it takes to get places?
Travel limited to C can make journeys between stars take years rather than centuries. Macleod's "Engines of light," has this as a major world building point.
Read again. That was not the question asked.
I still do not understand. Ok, so we break the laws and can travel at precisely the speed of light? But if we break those laws, warp drive, hyper drive and all (Wormholes!) why stick to travelling at PRECISELY the speed of light, why not go above it? In relation to known physics, it's as possible/impossible speed=c or speed>c. Same thing. Edit - actually I think the concept of speed precisely equal to c is worse than speed above c. Mathematically we can handle imaginary numbers way better than division by zero. Also the concept of speed is itself measurable and will have an error margin. And space is not a perfect vacuum and even photons interact with particles, and a massive ship would have particle interactions with solitary atoms on the path it travels. I am not sure we can talk of a physical object as being feasibly travelling through space as photon (or neutrino) would...
The Light Brigade has travel at exactly 1c
Starfarers by Poul Anderson. Does not have FTL, but travel at near the speed of light, with all the relativistic effects.
Charles Stross’ early novel Scratch Monkey, available free from his web site. People travel as radio at a speed determined by how much error correction you want…
Newton's Wake Relation Space Series (Skys Edge being the most based around it)
Cool I'll give them a look
Tau Zero comes close iirc
> Tau Zero comes close There are a few ways this could be interpreted but for a mathematician... this a perfect pun!
There is a number of stories in Larry Niven's "known space" universe which use non-FTL ships. In this universe, humans bought FTL technology from aliens during a war with another alien species; there is a number of novels and short stories from before humans got FTL. Some novels (by no means all): "A Gift from Earth", "World of Ptavvs", "Protector". In this universe, there are Bussard ramships (using a magnetic field to gather interstellar hydrogen for fuel) and also slowships (1/3 lightspeed, used for colonization, because early ramships couldn't carry living beings; too much radiation). In general, Niven's stories pay at least some attention to science.
What did the humans use to purchase the tech?
Can't remember, but it was expensive (t was just the background of some stories, never the main point). In another part of the Known Space stories, the Puppeteers (which are much more technically advanced than humans) bought from the Outsiders a reactionless drive to move their worlds; they are still paying for it. In another story, the protagonists meet an Outside ship (Outsiders don't use hyperspace); the ship's drive brought the ship from near-lightspeed to zero in moments. It's also mentioned that this drive was for sale but nobody could afford it. Outsider technology is advanced but very expensive.
Expensive how though? Do the aliens accept USD or gold?
The whole Outsider stuff is just background and not explained in detail. Generally the Outsiders are a species which doesn't have a lot of interaction with humans; they live in interstellar vacuum at near absolute zero, they trade in information. They have nearly unlimited credit in human banks, so I assume they use human money for interactions with humans. It's mentioned (I believe in "Ringworld") that the Outsiders follow "starseeds" (a non-sentient vacuum animal which uses lightsail to navigate) but nobody knows why (it's mentioned that Outsiders will answer personal questions, but at a price which nobody can afford). The puppeteers used a tool which changes stars' radiation to lure a startseed near human space and the Outsiders which followed it sold the FTL drive to humans, which allowed them to win their war against the alien "Kzin" (described as sentient, aggressive and physically similar to tigers). Known Space is an interesting, pretty consistent, future history; there's a lot of background information fleshing it out. The Outsiders are kind of bit-players, Kzin and Puppeteers are major players.
Carolyn Ives Gilman's Twenty Planets series is set in a world where light-speed travel is possible, albeit not in ships.
You might try Endeavour by Ralph Kern. The ship goes at the speed of light so the passengers do not age as they travel.
Manifold Space (Steven Baxter) features light-speed portals distributed throughout the galaxy. To the traveler they move instantly, but to outside observers the move at lights-speed from origin to destination.
Curvature propulsion in Three Body Problem/Death's End get close to light speed. They create a gravity well in front of the ship, so that you can essentially accelerate forever. But they only pop up pretty late in the books and aren't seeing much actual use for travel in the end. They also have the nasty side effect in that they mess up the space time in the process.
In Baxters *Proxima*/*Ultima* duology there is a transport system like that. There is also a comic series that was from France I think that had exactly that but I can't recall the name. There human scientists invent an engine that transports the ship at lightspeed to its destination and they meet aliens who also only travel at the speed of light (though their engine is a lot less dangerous and more efficient). During the course of the comic characters make light speed jumps several times and always lose the appropriate amount of time relative to people that stay on Earth.
House of Suns has drives that approach the speed of light. really great premise but the ending is pretty abrupt imo
House of Suns
The only stories I know of that do actual "you are a photon" style, precisely-light-speed travel are MacLeod's "Engines of Light" trilogy and two short stories by Niven that I haven't read in so long that I can barely remember them.
I don’t think this is what you’re looking for (it’s sci-fi horror) but The Void by Brett J. Talley.
Three body problem has this at the end of the trilogy. They’re able to change light speed around the ship by a lot of stuff I don’t really remember. Basically humans can make it to like 75-99% of light speed by they’re work around and it also ends up having consequences
FYI, warp 1 on Star Trek is light speed, but we rarely see anyone actually use it when faster speeds are available, although there’s a scene in DIS that shows the most accurate warp jump in the entire franchise in terms of speed, distance, and time
Every Le Guin novel and short story set in her Hainish universe and they are incredible. She thought the primary reason FTL existed in most sci fi stories was for there to be intergalactic space war, which didn't really interest her.
The Enderverse novels use near light speed travel, and deals with the consequences of time dilation, with some characters living for hundreds of years due to frequent space travel. At least until the later novels when it gets really woowoo mystical and they can >!teleport anywhere in the universe just by thinking about it.!<
3 body problem. Space distoetion engine or what the correct name is.
John Ringo's Honor Harrington series? It's been a few years so I might be wrong, but I do remember that they didn't travel FTL.
David Weber wrote Honor Harrington, and they do have hyperspace travel. The only Ringo books I’ve read was the Troy Rising series, and that one uses gates for travel