FTL travel - impossibility?

[SpaceMarine93]

Frankly, in nearly every science fiction set in space there had to be some form of FTL drive. But we all know, as of now, nobody had figured an actual way of bypassing the light barrier.

Let's just say there really are absolutely no way to break the light barrier - absolutely no way at all, the Alcubierre drive was wrong, Wormholes can't open without a type of matter that doesn't exist, there's no alternate dimension that could be used by some form of Hyperdrive, no slipstream, no fold drive, no teleportation, no nothing. It is the absolute barrier, forever deny to us in everyway. Don't bother try to handwave it, don't bother finding a way to go around it, don't even THINK about it. Over, done, no way at all.

Supposedly there is no way to travel faster than light (at all, FOREVER), what are the implications for any future space based civilization? How far can we go? Can we colonize space or forever trapped in one solar system? How would that affect science and technology and human development over the aeons?

I'm not looking for examples or a solution to the light problem, I want to know what you think a realistic, non-FTL interstellar civilization would look like. Opinions?

[HMS Sophia]

Colonies have to be set up to run on their own from day one. If something goes wrong on your generation ship, you are fucked, there is no way help is coming from earth...

Saying that, I don't doubt we would one day see colonisation of distant stars (or rather, their planets), mainly because we're explorers (as a race). Sending a generation ship to alpha centauri (assuming the planet could be made to support life) would happen, I don't doubt. Just don't expect to be getting letters if your brother signed up his family on the ship.

Of course we're not trapped. generation ships are a possibility, they are just a massive technological challenge.

[Interlord1]

I'd think that if any country actually bothered to send out colony ships to other planets or something, They would be sort of each solar system, or even planet, being an individual civilization. With no communication that doesn't take years, I don't think there is a way that an empire could be held together. But I guess trade would probably happen with some of the closer systems.

[HMS Sophia]

What would you be trading?
Say there is a colony on alpha centauri, and your realspace engines can rapidly accelerate you to 0.5c (some how). It would take 8 years for a ship to get between the colony and our lovely home world. Now, what would you be trading, that could still have confirmed value after eight years?
Okay, so there may be super materials on the planet. Something like room temperature super-conductors. But other than that? I mean you're not going to be shipping food. Maybe manufactured good? But in eight years, most of those would be obsolete, no?

[doom3607]

It would be an incredibly slow civilization, that's for sure- anything on the interstellar scale would be insanely glacial by our timescales. By the same note, such a civilization would probably be quite long-lived, and incredibly skilled at stellar engineering simply because they would need to be good at working on a massive scale to get from star to star. It would also undoubtedly be a very loose civilization, until they get immortality of course- when you're ten million years old, a four or five year delay to get a message from the nearest star isn't that long, now is it?

@barnest's only, since you posted while I was typing: Probably cultural stuff. Artwork and the like.

[HMS Sophia]

@barnest's only, since you posted while I was typing: Probably cultural stuff. Artwork and the like.

Good point. It would take the colony establishing itself first though. But yeah, I can see that (kinda)...

And yeah, it wouldn't be so much an empire, as a smattering of civilisations, all disconnected and functioning on their own, with very slow contact between them.

[Stofsk]

Supposedly there is no way to travel faster than light (at all, FOREVER), what are the implications for any future space based civilization?

Interstellar colonisation, should it take place, would require using generation ships or some method of propulsion that can get you there without requiring a great deal of propellant. Something like laser propulsion beamed onto a 'star sail' which would provide constant acceleration so long as the beam is on you and has enough power. That's one of the things Avatar had that I really liked.

How far can we go? Can we colonize space or forever trapped in one solar system?

There's no reason why you can't travel interstellar distances at sublight speeds, it is simply a monumentally challenging, time-consuming and energy-intensive task to perform.

I'm not looking for examples or a solution to the light problem, I want to know what you think a realistic, non-FTL interstellar civilization would look like. Opinions?

You have huge spaceships, with some method of propulsion that is not strictly speaking impossible like FTL is but so far we have no clear idea on how to make work (say something like fusion or antimatter drives), these spaceships would have a lot of volume devoted to propellant. Assuming you don't want a one-way trip, they'd also need some method of refueling when they arrive at their destination. First wave colonisation ships probably would be a one-way trip. I imagine you could posit a future where space telescopes that make hubble look like a beggar relieving himself at a bus station could have resolution enough to be able to detect planets orbiting distant stars. With this in mind, you could for example, determine if there are orbiting planets within certain stars (of G classification, maybe K or F as well) that are within their life zone. You might even be able to tell if they're habitable.

That way you don't do 'blind treks' like in Star Trek where they go to a star system and don't know before hand if there are any M-class planets on it. With this in mind, you'd only launch a colony ship towards the star in question if you know they have planets that are worthwhile settling on. On the other hand, you don't need to colonise planets anyway - not when you can hollow out asteroids and use them as habitats, or build O'neil space stations and start surrounding the sun with them. All the space and resources we could ever need are right here. But you would probably still have dudes who want to explore the stars, and when you're talking about a mature space civilisation that has millions of space habitats getting constant energy via solar power, all the infrastructure and production you could want by simply being a space civilisation, and all the material resources you could use that's already here in the solar system, constructing star ships could possibly be viable.

Communication would take ages, but that doesn't matter. Anyone who gets onto a starship has to have the attitude that they're either on a one-way trip or at best, when (if) they return to sol decades, centuries, hell even millennia may have passed by. It stands to reason then that colonisation would be done as much as 'to get away from' sol than it would to be part of the Earth Empire or whatever. Also, you could posit a future where aging has been eliminated or at least curtailed enough that trips in interstellar space might not result in everyone you ever knew being long dead before you return.

Another possibility nobody ever mentions is the use of unmanned exploration probes to visit stars and solar systems. I'd have to think that making a probe with the capability to reach distant stars and then beam the signal back to earth or its launch base would be a lot easier and cheaper form of space exploration than building the USS Enterprise.

Also since barnest2 asked what you could trade, every alien world with a biosphere is a potential gold mine for biotech research, anything at all really scientific. You'd have people with huge interest in getting information, specimens and going there to do field studies. A completely alien biodiversity would be priceless IMO. If you're a mature space civilisation, you wouldn't value the kind of crap we value. Who cares about mineral wealth when you can get all that shit from asteroids? But stuff like an alien world which has life on it would be something nobody would turn their nose at, and there could be huge potential in that.

[doom3607]

Actually, mining's even easier if we figure they can finally get von Neumann tech going. I mean, we probably have the necessary tech base to build simplistic, large ones in fairly short order now. Mineral wealth for everyone!

[HMS Sophia]

Also since barnest2 asked what you could trade, every alien world with a biosphere is a potential gold mine for biotech research, anything at all really scientific. You'd have people with huge interest in getting information, specimens and going there to do field studies. A completely alien biodiversity would be priceless IMO. If you're a mature space civilisation, you wouldn't value the kind of crap we value. Who cares about mineral wealth when you can get all that shit from asteroids? But stuff like an alien world which has life on it would be something nobody would turn their nose at, and there could be huge potential in that.

Yeah, sorry, I was thinking trade in terms of current sea trade, food stuffs, minerals and such.

[Stofsk]

There may even be some miraculous substance, let's call it unobtanium, which would have huge benefits to industry were it harnessed.

[doom3607]

As long as it isn't guarded by blue people who live in giant trees and talk to a planet-spanning semi-hive-mind they treat as a god.

[Stofsk]

well that's what asteroids are for am i rite :V

[doom3607]

Precisely.

[GrandMasterTerwynn]

Frankly, in nearly every science fiction set in space there had to be some form of FTL drive. But we all know, as of now, nobody had figured an actual way of bypassing the light barrier.

Let's just say there really are absolutely no way to break the light barrier - absolutely no way at all, the Alcubierre drive was wrong, Wormholes can't open without a type of matter that doesn't exist, there's no alternate dimension that could be used by some form of Hyperdrive, no slipstream, no fold drive, no teleportation, no nothing. It is the absolute barrier, forever deny to us in everyway. Don't bother try to handwave it, don't bother finding a way to go around it, don't even THINK about it. Over, done, no way at all.

Supposedly there is no way to travel faster than light (at all, FOREVER), what are the implications for any future space based civilization? How far can we go? Can we colonize space or forever trapped in one solar system? How would that affect science and technology and human development over the aeons?

I'm not looking for examples or a solution to the light problem, I want to know what you think a realistic, non-FTL interstellar civilization would look like. Opinions?

A slower-than-light civilization can expect to spend at least the next ten thousand years inside its own star system. Why? Because interstellar travel will be bloody expensive, no matter how you do it. Generation ship? You will need to wholly sustain an entire ecosystem for centuries or millennia as the ship crawls from one star to the next. Anything faster, you're going to need to expend huge quantities of energy. You will end up, say, dismantling the planet Mercury (and possibly Venus too, since the damned thing would just get in the way, what with it forming orbital resonances with your carefully placed arrays of accelerators and all) in order to paper the inner solar system with solar-powered antimatter generators, or with enormous swarms of statites or masers of stupendous size.

But, being inside your own star system isn't really that bad. If you converted the entire mass of the asteroid belt into O'Neill Island Three cylinders, each massing about 18 billion tons with a maximum population of over 10 million people (assuming a population density equal to that of Hong Kong) you'd have 2.084 quadrillion (i.e. 10^15) people in the solar system . . . or close to 300,000 present-day Earths. Disassemble the Earth, and you'd have room for 3316 quadrillion more. If we assume that Earth is left intact out of some ancestral affection for the ball of rock that's both nurtured us and done its level best to kill us, and disassembled Mars instead, we'd have room for just 356 quadrillion more people. Quite a few more if we do the whole post-human digital upload/download thing, in which case, we could leave Earth superficially intact, but turn it into the Douglas Adams Memorial Planetary Computer and use that as the transhuman server farm (or, possibly, somehow exploit the layers of diamond that might lie on the surfaces of the cores of the gas giants.)

Such a civilization could, as an interesting mental exercise, do things like construct giant mirrors in orbit around Jupiter and see if there's anything living on Europa worth kick-starting, or colonizing Callisto and Ganymede. In which case, you'd have humans adapted to the lower gravity and peculiar chemical cocktails required to make liveable atmospheres without building a mirror so huge that the giant dirty snowballs simply evaporate away under the concentrated sunlight. You'd also have humans adapted to whatever cultural whims affected their corner of the system (they might be post-biological uploads in boxes, or cyborgs, or have engaged in some manner of genetic engineering to produce anime catgirls, or some shit like that. They might also choose to inflict engineering on dolphins, great apes, elephants, and large parrots (assuming we don't kill them all in the next few centuries,) as well as common household pets.)

With up to several thousand quadrillion sapient human-based lifeforms crawling around the solar system (well over half a million present-day Earths,) you'd have greater diversity than the most lovingly-described contemporary fictional galactic empires.

But, getting back to the interstellar travel question . . . colony ships would likely employ some sort of biological stasis (either by freezing the people to the point of becoming water glass, engineering them to be able to survive being dehydrated to the approximate water content of an Egyptian mummy, or else just storing their digital brains on a server and printing out biological bodies for them upon arrival using highly sophisticated 3D printers,) coupled with high travel speeds (as in a few percent of light speed. A few tens of percents of light speed for probes,) since the best way to minimize the chances for disaster is to spend as little time in transit as possible. These colonies would be wholly self-sufficient from the Solar System, and they'd be going to their target stars with near-absolute certainty of what lies in store for them (since we'd be studying them with massive interferometric telescope arrays and interstellar probes for many, many years beforehand.)

If they were to ever trade, it would not be in physical artifacts. It'd take far too long and cost far too much to ship a painting or sculpture or whatever back and forth. Instead, they'd trade bits of data. If you want to admire the best of Alpha Centauri's 63rd wave of classical Cubist revival performance art, you'd beam the appropriate instructions for your utility fog/3D printer to print the thing out at the Lourve and have it look and feel just like it did when it was created by the original artist.

If one were willing to pay for the cost of energy to do so, and were willing to accept the risk that something would happen to you en-route, it is conceivable that people could travel between the stars . . . as digital uploads beamed from one transmission station to another. If you somehow got bored with half a million modern Earths worth of diversity, you could walk into a transmission station and wake up on the wild frontier of Epsilon Eridani.

[Simon_Jester]

For entertainment, the only cost of sending it over interstellar distances is electricity, which is effectively free in a "settled the whole star system" environment. So you'll see stuff propagating over interstellar distances even if it doesn't obviously have an "objective" qualitative edge over the domestic products- witness the sheer numbers of North American anime fans if you don't believe me.

[Lord of the Abyss]

As I envision it, all or nearly all physical travel between stars would be by small probes, including Von Neumann probes. Being much lower in mass than a generation ship they could be accelerated much faster for much less energy. When a Von Neumann probe gets to a system previously determined to be interesting, it decelerates, locates resources, then starts replicating. It and its descendants build an industrial and life support infrastructure and a powerful laser transceiver.

When all is ready a laser message is sent to nearby known-to-be-settled systems. When and if any humans (or whatever comes after us) show up, they don't show up in ships but as pure data transmitted via laser, with bodies (if they are desired) constructed on location. Travel as data on a laser takes less energy than a ship and travels at lightspeed by definition. And while not everyone would agree that a copy is "them", it doesn't matter much since in the end the people who do consider a copy of their mind to be them will win the argument just by being the people who colonize the galaxy.

[Connor MacLeod]

FTL is for weiners.

Funny, I recall Luke Campbell still being a proponent of some forms of FTL travel, and even coming up with some novel and interesting ways to pull it off.

Start thinking with habitats and soon, you'll start laughing in glee at our own prospects too! There's enough room in our solar system for infinite diversity and infinite combinations of mankind. Being "trapped" in a single solar system is hardly limiting!

And what if I don't like habitats? I know I could have millions or billions of habitants potentially, but what if I want planets in my sci fi? There's only so many of those you can cram into a system.

Yes, you can pull off reasonably well written sci fi without going outside a system or even planet. Many sci fi authors have done it - Heinlein's Moon is a Harsh Mistress, Niven's Ringworld, etc. But there's no reason to limit it to just that or denigrade other approaches just because hard sci fi has become the current fashion either. Especially since it's quite likely the next generation of sci fi fans will be looking down their noses at your ideas

Again, what matters less is realism and numbers, and more about plausibility and internal consistency of the story. Unless sci fi starts to become technical manuals at some point!