Wednesday, December 28, 2011

A Place to Call Home

Lunar eclipse above the Rockies
Extrasolar 'Earths' are still in the news, for a fairly loose definition of 'Earth'. Thanks to the Kepler mission the news stream of 'Earths' is likely to continue. Upwards of 200 candidates have been identified, most of which will probably not turn out to be false positives.

Surely some of the not-false-positives will orbit within their parent stars' habitable zones, calling for more detailed investigation. We will then search for signs of atmospheric water vapor, and especially oxygen - a substance so unstable and corrosive that its presence in significant quantities probably indicates life, and complex life at that.


Meanwhile, last post's comment thread drifted to a familiar topic in these parts: permanent, large scale human habitation in space. The 'large scale' part, especially, tends to pushes this subject beyond the Plausible Midfuture, which will have its work cut out producing a 'substantial' human population in space.

(Today's persistent space population is six. If it increases by an average 2 percent per year there are a decidedly modest 250 people in space circa 2200; at 3 percent per year some 1500. At 4 percent per year the space population is close to 10,000 people by 2200. Not so shabby, really. But bear in mind that all such compound interest calculations eventually bump up against something.)

Set aside the question of why - other than sheer coolness - we would colonize space at all. Also set aside, for now, those niggly questions about affording it.


An important, under-discussed aspect of space habitats is whether most humans can readily adapt to living in a can - and, if so, how big a can it takes. This issue was first pointed out to me in an email exchange with Matt Picio, a longtime regular at SFConsim-l. It came up again in the last discussion thread.

Putting it a more immediate way, how long can we be comfortable with never going outdoors? And what qualifies psychologically as being outdoors? We already know something about this without having to go into space, as the phrase 'cabin fever' suggests. Experience with nuclear submarines provides a baseline; so does over-winter habitation in Antarctica. But these habitats are on the same order of size as ordinary ships and buildings.

Space habs, intended for long-term occupation, are generally imagined to be at least an order of magnitude larger in sheer size, and an order of magnitude less cramped for their occupants. We do not have any examples on this scale to go by.

In popular imagination there are supposed to be Manhattanites who have no interest in riding the subway to the outer boroughs, let alone visiting the Big Sky Country. (They may or may not exist in any significant numbers.) But Manhattan is not an enclosed can - even its canyon streets are open to the sky. If Manhattan were domed over, would Central Park still feel like a park, or merely an indoor garden?

The question may not be purely a matter of (habitable!) physical space. Parallax depth from our binocular vision becomes 'infinity' at a few hundred meters; other cues (perspective; haze or lack of) can extend this to kilometers. My subjective impression is that mountain cabins on valleys less than a km or two wide feel confined.

Other factors both physiological and psychological could come into play. How rich an ecosystem is required for a healthy variety of smells and sounds?

Does it matter whether we are talking about an O'Neill-esque spacehab or a domed hab on a planetary surface? Does it count as 'going outside' if you have to stay in a vehicle or put on a spacesuit? I have also noticed, during long train rides, that in spite of the spectacular view from the dome car the impulse to step out of the train during station stops becomes very strong.


Presumably these concerns would not arise on a habitable planet, whether naturally so or terraformed. (But can we be completely sure of this?) And they may not matter for gigastructures approaching planetary dimensions, with rich ecosystems to match, and means other than domes or bulkheads to hold in the air.

But the overall point is that long-term human habitability may involve constraints going well beyond those that apply to spaceships that reach their destinations in a few months.

Discuss.




This image of the recent lunar eclipse above the Rocky Mountains comes, as so often, from Astronomy Picture of the Day. And a link to Atomic Rockets, just on general principles.

182 comments:

Thucydides said...

Wanderlust is probably hard wired into us, given several million years of hominid existence as hunter gatherers. Even as Homo Sapiens, most of our existence has been in the great outdoors.

OTOH, our "civilized" ancestors for the last 5000 years were tied pretty closely to their plot of land, ancestral village or the inside of the city, and rarely left the local area for any reason unless uprooted by disaster or war. (Voluntary displacement by merchant adventurers and mercenary soldiers was limited to a small minority). Cheap, large scale travel is really something dating back to the Industrial Revolution, so the idea of going on "vacation" is pretty recent, as far as these ideas go.

I can imagine a sort of high tech neolithic existence during the terraforming phase of planetary living. People would migrate from ecological "hotspot" to "hotspot", drawing on the resources there and perhaps creating and tending oasis they find in between. This does imply some sort of "base" to start from, or a magitech level of civilization, so this isn't the template for terraforming Mars.

Tony said...

I think it's important to note at the beginning of the discussion that being stuck on the farm or in the city is not a preferable form of living for most people, even if it has been the most common one. Even an O'Neillesque habitat would provide little more scope than most city dwellers or farmers have had throughout history. (Even if one didn't go far-ranging, it was certainly possible to walk several kilometers this way or that just looking for a new job or home, or travelling to market.) So the bottom line is that living in enclosed habs of any credible size is a serious regression from what we nowdays think of as the normal geographical scope of a middle class life.

Damien Sullivan said...

It might just be me, since I'm an urban and not very outdoorsy feeling, but I've noted that 3+ story ceilings, as in conservatories or malls or some airports, often feel sufficiently outdoorsy to me, especially if coupled with good light, plants, and water features. If I can see banana tree leaves in (pseudo) natural light, I may not care that I can see trusses beyond.

I'm a big fan of such "outdoors indoors". Examples include any greenhouse tall enough to contain un-stunted trees, a mall in Tokyo that had no natural light but managed to look like a little Italian village with blue sky and clouds, (I haven't been to this one) a big indoor beach resort in Japan, ironically right on the actual beach but with much better weather and water temperature...

I wouldn't want to live in conventional corridors and rooms all the time -- I prefer my basic living space to be like 9 feet high, good for halogen indirect lighting -- but access to 3-4 story 'outdoor rooms' might keep me happy.

I do like my occasional long view, but then the average O'Neill arguably will have too much view...

Also note there's what some people need, vs. what everyone needs. If living 'indoors' is something some people like, or can like if they're raised in it, then that's all you need for colonization. The people addicted to Big Sky Frontier will inherit the Earth, the agoraphobes will go to the stars...

As for exploration horizon, yeah realistic O'Neills are small. Efficient transport between nearby colonies is probably really important. OTOH, it's worth remembering that the 1970s O'Neills looked like suburbia or farmland. A more urban like density, which is economically more realistic unless you have von Neumann constructors, gives you a much higher population and range of activities to interact with.

Cities like New York also include things like Central Park these days. I'd expect colonies to have high-urban density, along with parks and greenhouses one could escape to for tickling one's biophilia. Manhattan with a mix of high ceilings and greenhouses, not suburbia.

Anonymous said...

I think that a view of the sky, or the illusion of a view of the sky, is important to the psychological health of most humans. If a domed city, make the dome transparent or have plenty of windows (high def jumbotrons may suffice), and have windows (or strips of optically pure quartz several kilometers long) in O'Neill-type orbital can-cities for a view of the sky...
Just some thoughts.


Ferrell

Z said...

A few SF writers have gone to the extra step of acknowledging that habitat design will be a wickedly challenging and important discipline- it's rather easy and tempting to build Stalinist apartment blocks (or jails) and I don't think that exactly what Asimov/O'Neill/etc. had in mind. It's part of why I've always been a bit dubious of "islands" in the first place- people routinely endure crummy housing to be close to somewhere interesting (and interesting doesn't necessarily mean hospitable) but L5 is not such a place. Then again, neither was Vegas, or Salt Lake City, or Dubai, and yet there's civilization there- it's always hard to parse exactly when having enough people in a place renders it a destination irregardless of the natural conditions.

Back to the design though- it'll be a beast and no one will do it until some really horrific habs have been constructed, because parks cost just as much to shield as anything else. Most of the research to date shows that maximally comforting human terrain is largely keyed to where you grew up, but there is also a common layer that is big on mixed wooded and open areas, mixed elevations, moderate exertion required to get around, and microspaces- hidden coves or caves or the like. Now, I can imagine a really clever person with really good values for exactly how much of each of those you need could fit a lot of tolerable habitat into a pretty small (by SF standards hab) but I'm not sure.

When it comes to planetary surfaces, however, I've always felt that the key to cutting down on the environmental malaise wasn't about habs, but about suits- really, really good suits. Suits that a person could stand to wear indoors if they were going to be going in and out like a coat. The mechanical counterpressure garments people are working on these days might get close if they include some means to relax when its no longer important to squeeze you. Something on the scale of a expedition mountaineering garment is the right scope I suspect- it's big, thick, between oxygen and goggles your face is covered, but the experience of being outside is still sufficiently genuine that getting into a tent the size of a living room rug comes with a brand of relief. If a really good suit can invert the relationship like that, and turn the indoors into the indoors instead of a bottle earth, and I suspect things get much better.

Thucydides said...

Dubai is an example of what is possible with essentially unlimited resources, if you are really looking for unlikely imagine a ski slope in a desert environment...

A highly "fractal" environment with lots of hidden niches and "reveals" as you walk around the landscape will probably be comforting for people living there, and of course a lot of vegetation will make it better. Even a small "village" built this way will be large enough to keep people satisfied and discovering new things over an extended period of time. (Think of how the heroines of Miyazaki films stumble upon the magical realms; or even just discovering a different slice of life like in "Whispers of the Heart").

Given space and exoplanetry environments in general are more hostile than any environment that we have colonized on Earth, it should be no surprise that people will be living in cocoons for a long time to come; Antarctic habitats or undersea stations are very small, and current space habs or even proposed ones like Bigelow Aerospace are not really much bigger...

Economics and technology will limit the sizes for a long time to come, we will have to wait a long time before we see "Bishop Rings" or other super sized habitats.

Christopher Phoenix said...

It seems that space habitats are the indoor garden designer's dream. You can mingle living space with gardens, hidden coves, and so on. My question is, how much will it cost to live in one?

"When it comes to planetary surfaces, however, I've always felt that the key to cutting down on the environmental malaise wasn't about habs, but about suits- really, really good suits." -Z

A mechanical counter pressure suit pretty much fulfills that need. Bear in mind that MCP suits are about as modest as a coat of paint, so our intrepid astronaut will need to have some other covering over her suit.

Skintight suits are far more flexible and convenient than the inflated rubber tires NASA has used so far. For more hostile conditions, I want E.E. Doc Smith style space armor. Armor plating to deflect bullets and micrometeoroids, thermal protection, enough shielding to deflect the output of a blaster...

With a small tank of algae in your backpack, you could even have long-term life support. That will be useful if space pirates board your space liner, blow holes in the walls, and you have to battle them in the wreckage of the first class lounge.

Only trained individuals will be venturing into the vacuum- not space suburbanites in their hidden coves.

Lets go rappelling down Martian cliffs in our skintight spacesuits!!

EXTREME SPORTS IN SPAAAAACEEEE!!!!!!!!

Mangaka2170 said...

One thing we're ignoring is the effect of long-term adaptation. It strikes me that the first space habs are probably going to be starkly efficient in layout, leaving not much space for non-essential purposes. While there may be a promenade or a market to facilitate trade, that may be the largest open area available.

However, the original inhabitants of these colonies are most likely going to be people who wanted to be there in the first place, and had met whatever rigorous requirements were needed to get into space. They would probably have trained extensively for all this.

Their children, on the other hand, would probably not know any life but living sealed inside a tin can for the long-term. They might adapt to such an environment more readily than their parents, or any other outsiders for that matter, did. In fact, they may come to be the agoraphobes that Mr. Sullivan suggested, although I think that "claustrophiles" might be a better term, especially if it's possible to get a view of the void outside.

Anonymous said...

=Milo=



Rick:

"Presumably these concerns would not arise on a habitable planet, whether naturally so or terraformed. (But can we be completely sure of this?)"

I would say no. If you live on an Earth-sized planet with a sprawling natural ecosystem, and a single outpost of civilization numbering twelve people, with communication times to home being in the order of weeks, then you probably will start feeling trapped. Particularly if aforementioned sprawling ecosystem comes with predators or other dangers included, making you wary of venturing too far from your outpost, effectively boxing you in with invisible walls.



Ferrell:

"I think that a view of the sky, or the illusion of a view of the sky, is important to the psychological health of most humans."

So does a field of stars outside your vacuum-sealed window count as sufficiently "sky-like", without having any analogue to the day sky?


"If a domed city, make the dome transparent or have plenty of windows"

I always just assumed that domes would be transparent. No sense wasting perfectly good sunlight.



Z:

"A few SF writers have gone to the extra step of acknowledging that habitat design will be a wickedly challenging and important discipline- it's rather easy and tempting to build Stalinist apartment blocks (or jails) and I don't think that exactly what Asimov/O'Neill/etc. had in mind."

If the habitat is a true city, rather than an just outpost for people on the payroll of the company that built it, then housing is going to be privatized to some degree - the habitat authority supplies the space and oversees construction to ensure proper safety protocols are followed, but they wouldn't micromanage all design and construction.

Geoffrey S H said...

Travel between colinies might be quite frequent, so as to see somethintg"different".

As for earlier peoples being confined to villages, the next village is further away if you can only walk- the area might seem a lot larger to people of earlier times.

As for domed cities on Mars, maybe underground might be a better location- larger tunnels and caverns opened up, with less steel required for structural support and ecosystems existing there.

Nothing beats terraforming for creating a human environment though.

Skírnir said...

Hey folks,

didn't follow the blog in a while, now I've been catching up over the holidays. ;)

> With a small tank of algae in your backpack,
> you could even have long-term life support.

I'm afraid a small tank won't get you anywhere. A human needs about 0,84kg of oxygen per day. An earthside, solar-powered algae reactor with this output would mass about 3 metric tons (90% of the mass being water). Even if you optimize the process, I doubt you can get it below 500kg, let alone any size feasible for space suits.

Compare to that, a 10 litre bottle is about 10kg empty, and at 200 bar contains about 2,5kg of oxygen, enough for 3 days.

For a habitat, however, I'd prefer a garden or park to produce at least some of the required oxygen, and benefit from the psychological effect of real plants.
However, for any "plausible midfuture" setting, I reckon this will only be viable for stationary habitats, be they orbital or planetside, and way too massy for use aboard a spaceship.

In my setting, I am using drives that cut down interplanetary travel times to manageable levels, for example Earth-Jupiter in about 6 weeks. This permits the ships' accomodations to be rather spartan, because the crew can recoup between trips.

jollyreaper said...

Well, we've got two big questions here.

1. What's the purpose of the "space"
to begin with? Temporary housing, permanent home, generation ship, etc? You'll note just how much space is required per passenger for duration of travel. You can be reasonably asked to sit in a seat for a 12 hour flight but trains require better seats, more ambling room, and those trips can last for a day or two. Cruise ships are the upper end of transit and require a lot of public space to avoid the tin can feeling. If a journey were to take months, more space required. If it's a permanent habitat, even more.

2. At what tech level are we talking? We have our privileged western view of what's required but that isn't always what's necessary. So if necessity calls, we could see some very sub-optimal solutions that might work but aren't pleasant.

We've seen too many starships that are basically modern ships translated into space. More exotic ships were present in the scifi past but we've kind of standardized on the tin can model, especially for visual scifi.

My personal bias is towards ships that feel more like cities than tin cans. Granted, this is not mid-future technology here. But I like the idea of an entire city in space, tens of thousands of people not just as a quasi-military crew on a mission but as families and neighbors. I like the idea of a starship big enough to carry entire ecosystems along for the journey.

The point above about the second generation being quite comfortable with the environment they grew up in is right. Kids who never had woods to play in behind their house don't know what they're missing. The question of whether this is something they should have for an enjoyable childhood is a separate question. Someone who grew up on a ranch riding horses would consider a life without such things to be dull and uninteresting whereas a city dweller would consider a childhood without malt shops and comic book stores a short walk from home to be privation. The country kid would consider the city a noisy, dirty, dehumanizing place and the city kid would consider the country to be isolated, backwards, and cut off from all the things that are interesting.

jollyreaper said...

If we did get very serious about building permanent space colonies, I think it pretty much goes without saying that we would construct early prototypes here on Earth first to test out the engineering and psychological issues. Even if the first generation colonists are psych screened for compatibility with the environment, there's a serious question of how the children adapt. I would assume most kids would be used to the environment they grew up in but what if the likelihood of compatibility is still around earth-normal? The Navy screens for claustrophobia with submariners and even at that there's still people who make it through training and training cruises and don't crack until they're on a real deployment. Those people can always be put back ashore. What do you do with kids who can't hack the colony when they're stuck on Mars?

There's also the ethical implication of this sort of experiment. The people who signed up for Biosphere 2 knew they were only in for a year or two. The volunteers who conducted the simulated Mars mission and were locked in tin cans for a year knew there was an end to it. To properly simulate a lifetime in a colony, they'd have to be locked in without the chance of getting out. The kids they have inside would have to be kept inside, never allowed out or else it would taint the experiment. But none of these kids would have consented, their parents made the choice for them. If it's wrong to put them in the experiment on Earth, is it wrong for their parents to take them to the colony?

That's one of the things that would suck on a generation ship, being born into one of the middle generations on a centuries-long trip. Hey, kids! Your ancestors left this really cool world you can see all about on the history vids. Your descendants will make a really cool place where you're heading. You, though, ain't gonna see any of it. Tough luck, man.

Tony said...

I think we to but to bed forever the idea that the people who move into space will be highly qualified volunteers. Highly qualified people may want to visit space on carefully planned expeditions. But they'll want to come home, meaning back to Earth. History tells us that people who actually go to live in space, jsut like any other frontier, will be going because it's the "best" choice out of a set of bad ones.

Now space may eventually become an attractive option, but only after much groundwork is laid by people who nobody really GAS about their comfort or happiness. Ground testing of habitats will only extend to making sure they work and that they're comfortable enough to reduce suicide and kill-craziness to a minimum acceptable level. Many of the first cohort of permanent space residents may not even live in facilities intended for lifetime occupation -- they'll just make do with what is available after they decide to (or circumstances make it apparent that they must) spin out the balance of their existence in space.

Anonymous said...

=Milo=



Geoffrey S H:

"As for domed cities on Mars, maybe underground might be a better location- larger tunnels and caverns opened up, with less steel required for structural support and ecosystems existing there."

Meh. You probably aren't going to find a natural cavern large enough to build a city in, and the work of hollowing out an artificial cavern would seem no easier than the work of constructing an aboveground dome.

And I think the cave would actually need more structural support than the dome to prevent a cave-in, since natural rock isn't likely to be the ideal material for the job.



Jollyreaper:

"I would assume most kids would be used to the environment they grew up in but what if the likelihood of compatibility is still around earth-normal?"

Although people definitely adapt to some degree to the environment they're raised in, the existance of the concept of abusive childhoods proves that there is a limit to how much children will put up with even if they've never personally experienced anything better.

The question is where the line is drawn.


"That's one of the things that would suck on a generation ship, being born into one of the middle generations on a centuries-long trip. Hey, kids! Your ancestors left this really cool world you can see all about on the history vids. Your descendants will make a really cool place where you're heading. You, though, ain't gonna see any of it. Tough luck, man."

Eeyup.

There's also the question of whether the final generation, at the time of arrival, has gotten so used to living on a ship that they're no longer interested in settling on the planet anymore...

jollyreaper said...


I think we to but to bed forever the idea that the people who move into space will be highly qualified volunteers. Highly qualified people may want to visit space on carefully planned expeditions. But they'll want to come home, meaning back to Earth. History tells us that people who actually go to live in space, jsut like any other frontier, will be going because it's the "best" choice out of a set of bad ones.


But you only need to see the examples of rich western people moving to ascetic hippie communes to see that "best" is a highly subjective judgement call.

The economic question is the big one. If it can't pay for itself, it won't succeed. If it requires the massive infusion of outside capital and the personal care of some great, wealthy and powerful individual, then it won't likely endure past his death. It's not sustainable.

The lower the cost of entry, the lower the difficulty. It's currently economical for someone to get a bug up his butt and live in a remote mountain cabin. It's possible for him to buy a private sailboat and lark about the world's oceans. But it would be very expensive for him to, say, build an underwater home. There's a repurposed Navy research habitat sitting in a lagoon in the Keys that you can rent out as an underwater hotel room but I've never heard of anyone trying to replicate it as a permanent residence.

Right now space is right at that cusp between major nation-state's game and powerful billionaire's game. And even at that we're looking at Elon Musk putting up rockets, not Moonraker colonies with fleets of private shuttles.

Still, if we look at dedicated cultists with a mission... The Pilgrims were dedicated cultists. The Scientologists operate their own compounds, had at one point a sea-faring home for Hubbard along with a hand-picked crew, control millions in assets. Nobody is sure just how many billions in assets the Catholics control but it's certainly a lot.

Historically, people would usually rather stay in their homeland unless the situation becomes dire. War, famine, disease, religious or political persecution, this makes settling down in a strange new land an opportunity rather than a punishment. And even in our own history, not all the people who leave the old country are poor and underprivileged.

We're also back to the economic question of what people would be doing for a living in space. I don't foresee a lot of hand labor. The rationale for bringing slaves to the Caribbean or Chinese rail workers to the US don't really hold as well. Any spice mines in space are likely to be highly automated.

jollyreaper said...

If we think about the economics of it too closely, we're pretty much back to having to agree that the libertarian fantasy of sovereign floating islands ala seasteading would have to be a reality before we could even imagine that sort of thing in space.

I still think that the most likely scenario towards getting people out into space is for there to be some kind of national prestige project to build space habitats, something not economically justified but pure flag-waving. Get enough people out there long enough and the second generation will be happy enough to stay out there. If there's any kind of repatriation problem, that would make them staying there even more likely.

The O'Neill idea of people heading out there to construct the solar power satellite array deemed necessary for our energy future seemed pretty good back when the book came out but even if every single one of his assumptions held true and we wanted to start constructing the facilities tomorrow, telepresence would likely mean nearly all the workers would be living on the ground. There would be a minimal need for personnel on-orbit.

That's one of the reasons why I think it would have to be a prestige project. Putting people in space isn't a necessary step in performing a specific task, they're the whole point of the exercise.

As far as political stunts, I would also be curious if we'll see something like scientologists trying to buy territory from some tiny nation and trying to get it made independently sovereign like Vatican City.

vasiln said...

Humans, as individuals, can be extraordinarily fragile. Humans as populations are ridiculously resilient. To me, that means that any significant number of humans can (at least) maintain their population in extraordinarily stressful situations-- but that comes at the cost of individual dysfunction. Few people consider crime, drug abuse, suicide in space habs. We don't have a good model for understanding stress on Earth, and we get around it by ignoring it in favor of a 'personal responsibility' model that frees us from a lot of the social burden. That works, sociologically, and is totally extensible to space.

Most discussion of environments and what our 'hardwired' needs are is conjecture. Would we need the open blue sky if we'd never seen it? There are no stress-free environments for humans for us to use a baseline; there are no environments that satisfy basic human needs that are so stressful that humans can't survive in them. It's not an either/or situation-- it's about how prone those populations will be be, probabilistically, to dysfunction.

The first space habitations are not going to be sprawling, wide open spaces. They're going to be spectacularly limited in terms of human comforts. As the cost of bringing materials to those habitations decreases, those environments will grow-- not in line with what we think is necessary, down here on Earth, but rather in line with what the inhabitants think is necessary. Will they choose better parallax for their money? Or meat? Or just better video games?

The amount of work built into a space hab is an interesting factor in this, because it's not just a matter of how much work can be automated. People with lots of free time get into trouble. It exacerbates social problems. I wouldn't be surprised to see design based around manual operation because of this.

Anonymous said...

Maybe we should think of first generation space colonies as technological and social 'seeds'; we plant them and provide nurishment until (or if) they can thrive on their own. Will this take years, decades, generations, centuries? We don't know yet, and we won't until after we build the first one.

Ferrell

Skírnir said...

I like the "seeds" image. One big factor is what scope of space travel the setting features: no interstellar travel, or STL, or FTL.

- in an interplanetary-only scenario (i.e. the most plausible), we're stuck with rather unhospitable destinations. If we colonize e.g. Mars at all, the best we can hope for would be domed cities - at least a scenic view would be possible, but the ecosystem is make-your-own.

- in an STL setting, we get those generation ships with all their implications. Basically you need a flying city, ah what am I saying, _county_ in spaaaace.
Also, I think we can assume that our direct neighbours won't have very attractive planets, and the next planet that's actually interesting for us would be at least dozens of light years away, so that colony can be considered "cut off" from Earth for all practical purposes.

- in an FTL setting otoh, the journeys will be relatively short, somewhere on the order of weeks probably, so the ships don't need to present a full ecosystem of their own; also you can afford the luxury of picking only _really_ attractive worlds for colonization, where even outdoor life may be possible.

So long story short, the focus on the living conditions will shift considerably depending on the setting being IP, STL or FTL.

Rick said...

Welcome to new commenters!

Other than that I have nothing especially profound to add at the moment. So carry on ...

Anonymous said...

I've read speculation that lava tubes on Mars, potentially larger than those on Earth, could be sealed, pressurized and used for habitation. Valles Marineris could also theoretically be roofed over and pressurized, likely making it the largest habitable space on a planetary surface (apart from Earth) in the solar system. This would probably be a multi-generational project, and might start in the relatively small canyons of Noctis Labyrinthus, at the western end of the region.

R.C.

Mangaka2170 said...

Another possibility would be to seal off the top of Olympus Mons. There's a lot of space to play around with in there.

Byron said...

I do have to question psychological adaptability for small space habitats. Antarctic winter missions are a few months. Ditto for boomers. Biosphere 2 was a disaster, and it's of similar size to what a lot of people propose. And while that program may not have done careful screening, they still did some.
I honestly don't know what it will be like, and we won't until we try it. Which raises ethical issues. I think that children might do well, given that the environment is probably safer for them then a city.

Sean said...

Skírnir said: "in an FTL setting otoh, the journeys will be relatively short, somewhere on the order of weeks probably, so the ships don't need to present a full ecosystem of their own; also you can afford the luxury of picking only _really_ attractive worlds for colonization, where even outdoor life may be possible."

That's quite the assumption, considering that at twice the speed of light it would still take you two years to reach Proxima Centuri.

Tony said...

Byron:

"Which raises ethical issues. I think that children might do well, given that the environment is probably safer for them then a city."

Safer how, and by what standard? The infant and child mortality rate is not exactly skyrocketing for middle class people who live in cities. There's certainly no guarantee that there won't be violence, anti-social subcultures, and everyday risks of accident or misadventure, simply because a community lives in a space habitat.

Sean:

"That's quite the assumption, considering that at twice the speed of light it would still take you two years to reach Proxima Centuri."

There's no reason to think -- or even suspect -- that FTL would mean just barely FTL, or just a few multiples of c. The real intellectual quandary is why there would be a speed limit at all. Certainly authors introduce FTL speed limits into their fiction, for story reasons, but in the real world (for certain values of "real") if you can go faster than light at all, why can't you go arbitrarily fast?

Christopher Phoenix said...

Roofing over Valles Marineris or Olympus Mons is an intriguing idea. I've read that we could colonize the Moon by sealing the entrance to a lava tube and filling it with air. That shows the advantages of making use of natural environmental features...

Milo:

You should use General Electric's 1962 plan for an underground lunar colony- just dig a hole and drop an atomic bomb down it. Down they go, up they blow, and then you insert a plastic bag, inflate, and voila!!! Instant lunar colony!!

If you want to dig out a cave for a really big underground city on Mars quickly, than you should contact your friendly local strategic nuclear forces and ask if they have an H-bomb going spare. They will be happy to sell it to the Mars Settlement effort for a discount. When in doubt, NUKE SOMETHING!!!

Tony:

"There's no reason to think -- or even suspect -- that FTL would mean just barely FTL, or just a few multiples of c."

We don't have any FTL physics yet. The limitations of FTL flight will depend on how FTL flight is achieved. There is really no more reason to think that FTL will mean 300,000c or 2c until we have pinned down a method of doing it. I don't see that you have any grounds to assume that FTL means arbitrarily fast, other than wishful thinking. Even if there is no limit to the speed of an FTL ship, there will probably be a limit to the capability of the stardrive.

In fiction, it is generally best to put some interesting limits on your FTL drives and see what kind of setting evolves from these constraints.

Antigravity and faster-than-light travel are two of my favorite fictional technologies. Some FTL ships in fiction use rockets for STL maneuvering, but others- like the United Planets Cruiser C-57D- use antigravity propulsion to take off and land from planets.

Anonymous said...

=Milo=



Byron:

"I think that children might do well, given that the environment is probably safer for them then a city."

But they're also limited in the activities, social interactions, and educational facilities they can pursue. And unlike people who grew up on Earth and moved into space, they will have never had these things.



Tony:

"Certainly authors introduce FTL speed limits into their fiction, for story reasons, but in the real world (for certain values of "real") if you can go faster than light at all, why can't you go arbitrarily fast?"

Engineering difficulties. My "standard" FTL assumption theoretically allows arbitrary speed, but there is a limit to what can be accomplished with current tech. This limit can then be gradually raised over the course of future history.

Possibly, higher speeds require more energy. This can also be used to explain typical FTL's difficulty in gravity wells - the deeper you are in a gravity well, the more energy you need, or equivalently, the slower you can go with a given energy output.



Christopher Phoenix:

"You should use General Electric's 1962 plan for an underground lunar colony- just dig a hole and drop an atomic bomb down it. Down they go, up they blow, and then you insert a plastic bag, inflate, and voila!!! Instant lunar colony!!"

I suppose waiting a few centuries for the fallout to decay is insignificant on the timescales necessary for colonization? ;)

Skírnir said...

re FTL:
Let's keep in mind that this something that, by definition, authors _make up_.
The actual point about FTL is that it's supposed to make travel between stars really fast. There is simply no point for an author to make up an FTL method that is limited to something like 2c, because it wouldn't be so much faster than STL. All the hassle with causality for none of the benefits -- not worth it.

Likewise, "unlimited" or "arbitrarily fast" FTL would be just the same can of worms opened from the other end, while you are looking at it from below. It's just going to cause problems, so authors are wise to impose some constraints, for example a maximum multiple of c.

That's why "practical FTL" used in most SF (at least the stuff I know) works out to some large but finite multiple of c, directly or indirectly. For example, Traveller's "6 parsec maximum per week" translates to 1000c. Fast enough to get places, but constrained enough to make you think where you want to go.
Even settings where you have Jump Drives that cover the distance instantaneously, there are usually constraints like charge-up, maximum jump range and cooldown times that effectively work out to a certain multiple of c.

In FTL settings, the FTL journey as such is usually not the focus of the story (and when it is, it's usually because something is going wrong). Mostly, it's just a tool for the author to be able to implement any number of new and interesting worlds, maybe even aliens, without butchering what we know about our home turf, and without having to worry about dozens of years passing between any two encounters as would be the case in an STL setting.

The standard STL response to "years and years of travel time" is "cryo-sleep". Imho, deep-freezing a person and then bringing them to life again is just as far-out magitech as FTL. But FTL allows a faster pace and fewer dead ends, so I prefer this method.

Jim Baerg said...

Milo: "There's also the question of whether the final generation, at the time of arrival, has gotten so used to living on a ship that they're no longer interested in settling on the planet anymore..."

Then the majority who like living on the ship build O'Neill colonies & eventually there is a large enough population in the solar system that there are enough weird people who like the idea of living on a planet to start a planetary population.

Re: FTL vs STL
There is also the interesting idea of the lightspeed drive. It makes travel time zero for the traveller, however going home is time travel only into the future, so no one will make such a trip on a whim. This makes it easy for colonizing expeditions & for cultural diversity to arise between colonized worlds.

I'd like to read more stories with such a setting than the few I'm aware of. Poul Anderson's "The Long Way Home" & the almost lightspeed magitech drive in "Starfarers" & the related 'Kith' stories. There was also as series of short stories in such a setting in Analog quite some time ago.

Does anyone know of some more?

vasiln said...

"Then the majority who like living on the ship build O'Neill colonies & eventually there is a large enough population in the solar system that there are enough weird people who like the idea of living on a planet to start a planetary population."

That's funny-- that's exactly the world I'm working on in my head right now. Complicated by the fact that the multiple redundant arms of the generations ship have forked culturally over their trip. (And complicated by a few other things as well.)

Christopher Phoenix said...

On FTL travel vs STL travel- I think you guys are missing something rather large here.

"The actual point about FTL is that it's supposed to make travel between stars really fast. There is simply no point for an author to make up an FTL method that is limited to something like 2c, because it wouldn't be so much faster than STL. All the hassle with causality for none of the benefits -- not worth it."-Skirnir

If by STL you mean "rockets", then the 2c stardrive may very well have many advantages.

Rockets have many limitations, especially when it comes to interstellar travel. The time of travel is an obvious challenge. However, there is another- propellent!!! All rockets require large amounts of reaction mass. The faster we want to travel, the more propellent we will need. Even the most powerful conceivable rockets will require enormous quantities of propellent to travel to another star in a human lifetime.

Then there are the energy requirements. Traveling at a significant fraction of C will require a large amount of energy, not counting the energy that is lost in the kinetic energy of the rocket exhaust and as waste heat. All this makes rocket travel at relativistic velocities rather difficult.

I don't know the effects or energy requirements of the "slow" FTL drive, but the laws of kinetic energy probably don't apply to a drive that beats the light-speed limit. I doubt a weird hyperdrive/space-warp generator/stutter-jump drive/etc. needs propellent either- a crucial feature. It might be slower than most SF ships, but it sure beats rockets for interstellar travel!!

If I had a Tachyon-1 drive with a maximum velocity of 2c, I'd travel to another star. Think about it. There's no rocket propellent- just a ball of exotic matter in the drive core. The ship isn't "moving" in the classic sense, so I don't require enormous amounts of energy. I'll assume that there is no time dilation with my drive.

At 2c, I'll reach Alpha Centauri in 2.5 years. I'll reach the nearest star with known planets, Epsilon Eridani, after 5 years of flight. If the average interstellar trip is around five years, there are quite a few stars I can visit. Five years to reach an entire new solar system isn't all that bad. This setting will be limited to local stars, but that is better than no star travel at all.

You are speaking from the point of view of a writer creating an interstellar setting. If I came to NASA with the design for a Tachyon-1 drive that enveloped a spacecraft in a tachyonic space-warp that traveled two times the speed of light, my feet would be sopping wet from the kisses.

Of course, as Rick Robinson will probably point out, the laws of my Tachyon-1 drive are arbitrary, as are all other FTL drives in fiction. At this point we are arguing about the arbitrary rules of fictitious technologies.

Skírnir said...

Essentially what you are saying is, with STL we are constrained by the laws of physics, while for FTL we can ignore them. Well, if it's just that, we can also make up a Reactionless Drive that allows us to go really fast STL without taking propellant with us.

Generally you're right with your technical concerns, which is why I say STL star travel is not necessarily more realistic than FTL.

(FWIW, "I can butcher the laws of physics without going FTL" is probably about the same as "We can get drunk without having fun", that just as an aside.)

Christopher Phoenix said:
"Five years to reach an entire new solar system isn't all that bad. This setting will be limited to local stars, but that is better than no star travel at all."

There's the crux -- five years to get to a new habitable planet would be fine. But we already have a pretty good idea about our closest neighbours: none of them appear to have any habitable planets. There's no reason to go through all the trouble just to end up at a place that's worse than Mars.
(Alright, maybe if the Sun were about to blow up - but personally I'm not particularly fond of apocalypse/noah's ark settings, it's been done quite often enough.)

My line of thought is roughly:
- if humans are supposed to go to another star, particularly for colonization purposes, it had better be worth it.
- we know there are no "Earth Twins" nearby, so if an author is to make one up, it has to be relatively far away
- if it is so far away, it's going to be a one-way trip. There's no difference whether Earth is actually gone or just too far away to go back; you're on your own either way.
_Unless_ the author also makes up a travel method that allows people to go back and forth many times without serious time dilation issues, in other words, fast FTL.

Anyway, I don't think it's necessary to open up another category besides STL/FTL. If an author feels compelled to create a "slow FTL" universe just for the hell of it, it could be grouped into the STL subgenre for most story purposes.

Damien Sullivan said...

I first encountered a lightspeed drive in Ken MacLeod's _Cosmonaut Keep_ and ensuing trilogy. Didn't realize it was a thing out there. LeGuin's NAFAL is apparently supposed to be similar, vs. being some huge-energy Bussard ramjet; of course she supplements it with the ansible for instant communication.

MacLeod's setting barely has spaceships. Use antigravity to go up, zip to another star in zero time subjective, go back down; no need to be in space for more than a few hours, if that, so ships are basically a big shell of air and water (kraken pilots), no need for extended life support.

Thucydides said...

In theory you can have STL without using huge masses of propellant; a giant solar sail sent on a hyperbolic orbit around the sun can be deployed at the perthelion and reach Alpha Centauri in about a thousand years. A giant mass driver could also project a spaceship on an interstellar trajectory (and of course there is always the Robert Forward beamed lightsail idea as well).

I tend to "believe" in the idea that FTL, if possible, uses such different laws of physics that you would still need normal STL space travel to get around in normal space. The Alderson Drive (Mote in God's Eye) or wormholes in deep space (The Forever War) would be the models to use. This allows for Space Operatic settings, and you can tailor your spacecraft to whatever suits your story (Massive Imperial battle cruisers from the Mote in God's Eye seem based on WWI ships, while the ships in Forever War evolved over a thousand year story arc.)

Given the known sample of planets and exoplanets, even these sorts of FTL would still require long expeditions to reach a shirtsleeve planet; people will be building habitats and colonies out of sheer necessity anywhere in the Solar System or the local group of stars.

Skírnir said...

FWIW, for my pet universe I devised an FTL concept where you can "jump" between stars, but to initiate the jump you have to be stationary relative to the target star. So you first have to match vectors before you can kick in the drive, which can take up to a couple of days.
You pop out somewhere on the star's polar axis at 0 velocity, and can accelerate from there to get to the planet you want to reach. Interplanetary travel is reasonably fast but still takes one to several weeks for typical distances (0,5-7AU).

What I haven't figured out yet is how long the jump as such should take. I only decieded that the crew would perceive the time as very short. If it were in fact instantaneous, the fastest route from Saturn to Earth would go via Barnard's Star, and I don't want to permit that because it feels like a cheat in a video game.

Anonymous said...

=Milo=



Christopher Phoenix:

"Even the most powerful conceivable rockets will require enormous quantities of propellent to travel to another star in a human lifetime.

Then there are the energy requirements. [...]

I don't know the effects or energy requirements of the "slow" FTL drive, but the laws of kinetic energy probably don't apply to a drive that beats the light-speed limit."


Other laws you get to dodge are time dilation and inertia (that thing that says you get smushed if you accelerate too much faster than 1 g).

Oh yeah, and Rick Robinson's first law of space combat.



Skirnir:

"(FWIW, "I can butcher the laws of physics without going FTL" is probably about the same as "We can get drunk without having fun", that just as an aside.)"

Hehe.



Thucydides:

"In theory you can have STL without using huge masses of propellant; a giant solar sail sent on a hyperbolic orbit around the sun can be deployed at the perthelion and reach Alpha Centauri in about a thousand years."

Wow! I gotta book one of those trips.


"I tend to "believe" in the idea that FTL, if possible, uses such different laws of physics that you would still need normal STL space travel to get around in normal space."

I prefer this for aesthetic reasons if nothing else - it gives you a reason to not just throw known science (and the spaceship behavior that comes with it) out entirely.

The transition can be hard (FTL only works at jump points, it just does nothing anywhere else) or soft (FTL costs more energy the deeper you are in a gravity well, beyond a certain point it's not worth using anymore).


"Given the known sample of planets and exoplanets, even these sorts of FTL would still require long expeditions to reach a shirtsleeve planet; people will be building habitats and colonies out of sheer necessity anywhere in the Solar System or the local group of stars."

There is little point travelling to another star system if the worlds there are no more hospitable than places like Mars in our own solar system.

Unless you're so far into the future that practically every body in our solar system has been exploited to its limit.



Skirnir:

"You pop out somewhere on the star's polar axis at 0 velocity, and can accelerate from there to get to the planet you want to reach."

If you're near a star at zero relative velocity, you won't be in orbit, and so gravity would pull you straight in. Better accelerate fast before you burn up!


"If it were in fact instantaneous, the fastest route from Saturn to Earth would go via Barnard's Star, and I don't want to permit that because it feels like a cheat in a video game."

How far from the star do you pop into existance after a jump? If distance at arrival is based on distance at departure, then your trick would just move you to somewhere else in Saturn's orbit, not very useful.

You could also make jump drives expend expensive fuel, giving characters a motivation to keep jumps to a minimum even if they're faster.

You can also reconcile instantaneous jumps with limited travel speed by having a charge-up/cool-down time between jumps, during which the ship can otherwise move around normally STL but cannot jump again.

jollyreaper said...

There are two ways around FTL complications and the plausible mid-future if you basically want to tell stories with spaceships that feel like modern navy ships.

1) Portals. The only skiffy assumption is that you can open a portal from one likely planet to another. Or maybe it's through another dimension. All the inverse tachyon timey wimey stuff is tied up in that one assumption and the spin-off technologies can be limited as part of the assumption. So if you want to have your intrepid crew exploring strange new worlds, they're in a navy ship and they sail it through a portal to a new planet.

2) Missile Gap variant. I dearly love Charlie Stross. He wrote a story called Missile Gap.

On October 2, 1962, the universe underwent a change - instantly, the continents of the Earth were no longer wrapped onto a spherical planet but were on the surface of an Alderson disk. Measurements on Cepheid variable stars indicate that the Alderson disk is located in the Lesser Magellanic Cloud, and that the epoch is roughly 800,000 years later than the calendar date (give or take 100,000 to 200,000 years). In the sky, the stars of the Milky Way are reddened and metal-depleted, evidence that it is now controlled by a Type-III civilization capable of controlling the resources of an entire galaxy.

The surface area of the disc is freakishly huge and beyond the original continents lie endless new land masses to explore. The US military uses nuclear ramjet cruise missiles as exploration probes. The nuclear ramjet uses a nuclear reactor rather than jet fuel to heat gases and shoot them out the back of the aircraft and the endurance is in months at supersonic speeds. Nuclear-powered colony ships are sent out to try to establish toeholds on the new continents which can be a year away at a 20kt speed.

How did this come to be? Competing theories:

1. the atoms making up the surface and people of earth have somehow peeled off the Earth and shipped to a new location

2. Marvin Minsky suggests that a snapshot of the world was taken and the snapshot has been used as the basis for a physical recreation

3. Hans Moravec suggests that a snapshot of the world was taken and the snapshot has been used as the basis for a simulated reality


The drawback to the Missile Gap approach is that Clarketech aliens have to exist. The advantage is that all of that technology remains out of human reach and thus the need for the author to explain it. All tech available to human characters remains real-world and explicable. While the portal approach precludes the need for aliens, it does require that humans control tech powered by pure, uncut handwavium.

I would maintain that either of those two approaches probably requires less complicated assumptions about human politics, economics social engineering, and plausible technology than the usual "colonize space" stories.

The obsessed Scholar said...

I would say no. If you live on an Earth-sized planet with a sprawling natural ecosystem, and a single outpost of civilization numbering twelve people, with communication times to home being in the order of weeks, then you probably will start feeling trapped. Particularly if aforementioned sprawling ecosystem comes with predators or other dangers included, making you wary of venturing too far from your outpost, effectively boxing you in with invisible walls."


Well, this is just me but the idea of the people back on earth not being able to reach me and having an entire unexplored world out there with only a handful of people is appealing.

As for predators, if I can eat their meat that's not such a big deal and there's always the thrill of the hunt.

Christopher Phoenix said...

"Essentially what you are saying is, with STL we are constrained by the laws of physics, while for FTL we can ignore them. Well, if it's just that, we can also make up a Reactionless Drive that allows us to go really fast STL without taking propellant with us. "- Skirnir

Well- yes and no. What I am saying is that some weird FTL space warp doesn't have the limitations of rocketry. That is a good enough reason to use the space warp generator, even if the drive doesn't travel that many times faster than C.

Many people- especially SF fans- know about the time travel issues of interstellar travel, but hardly anyone seems to be aware of the more subtle challenges. Rockets just use too much propellent. Here is a link to a NASA graphic showing how much propellent would be required for various "rockets of the future" to make a flyby of the Centauri Cluster within 900 years of launch time. Bear in mind that this graphic assumes we didn't provide any means to stop at the Centauri system or reach there faster than nine centuries.

Energy is another big challenge. Even if we had some nonrocket space drive that directly converted energy into motion without propellent, it would still require a lot of energy. Launching a shuttle-sized payload to the nearest star (subrelativistic speed) would consume 7x10^19 joules. NASA suggests that to overcome this difficulty, we need a breakthrough where we can take advantage of the energy in the quantum vacuum, a breakthrough in energy production physics, or a breakthrough where the laws of kinetic energy don't apply.

The bizarre space-warp generator that goes real sloooow compared to the likes of Star Trek beats the propellent and hopefully the energy constraints. This is why it will beat most STL drives.

Making up a reactionless drive is essentially butchering the laws of physics without going FTL- getting really drunk without having fun!!!

"Other laws you get to dodge are time dilation and inertia (that thing that says you get smushed if you accelerate too much faster than 1 g).

Oh yeah, and Rick Robinson's first law of space combat.
"- Milo

Quite true. Recently I had a case of the "Rick Robinson Blues" when I began considering the ramifications of relativistic spaceships. I don't mind wrecking enemy ships with hails of kinetic mines or even bombarding the surface of planets. However, relativistic weapons take things a little too far. If every starship is a significant threat to inhabited worlds, then most people won't be excited about relativistic travel being common.

However, I am not as worried about that anymore. Extremely fast relativistic ships (or weapons) are not likely given the propellent and energy constraints of rockets, the deadly space junk problem, and the induced cosmic ray problem. Relativistic effects spoil the efficiency of STL drives nearing the speed of light. We'll probably be limited to a fraction of the speed of light at most without a physics breakthrough.

Thucydides said...

A shirtsleeve environment planet would need a large and complex ecosystem (with carbon based life) to create an oxygen atmosphere and maintain it over geological time.

As for the creatures that live there, I expect they would make us very sick through allergic reactions to the alien protein analogues (and we them), so I'd go easy on the hunting...

Ships and weapons moving at a large fraction of c would be a huge problem, especially if something went wrong and the vehicle was no longer under positive control. Hitting any planet in the solar system or impacting the sun would create showers of secondary particles and radiation moving through the system, wreaking havoc everywhere. Even an inadvertent impact with a piece of space debris would probably tear the spaceship apart, leaving a cone of destruction streaking through the system.

Skírnir said...

> "As for the creatures that live there, I expect they would make us very sick through allergic reactions to the alien protein analogues (and we them), so I'd go easy on the hunting..."

Aye, true that. But a planet with oxygen atmosphere would be just too good to pass up on. IMS, they use a kind of biotechnology to adapt terran bodies to life in foreign conditions. Spacers can get adaptation to life in microgravity, colonists to their local atmospheric and gravitic conditions, as well as the means to cope with the local lifeforms, even digest the flora and fauna. Imported flora and fauna from terra can be modified in the same way.
In short, the term "body mod" receives a whole new meaning. =D

So these modifications would also factor into the whole topic of "a place to call home". Maybe the mods are backwards compatible, and maybe they aren't, or not completely... So once you get modded for a particular colony, you might even have trouble if you ever visit the homeworld again.
(Though for purposes of my setting, I am leaning towards making the mods fully backward compatible, as they are supposed to be an aid and not a hindrance.)

Anonymous said...

=Milo=



Christopher Phoenix:

"Many people- especially SF fans- know about the time travel issues of interstellar travel, but hardly anyone seems to be aware of the more subtle challenges."

Thank you. This is something that often bugs me, too.


"a breakthrough where we can take advantage of the energy in the quantum vacuum"

Which is techjargon for "we want to get something from nothing".



Thucydides:

"A shirtsleeve environment planet would need a large and complex ecosystem (with carbon based life) to create an oxygen atmosphere and maintain it over geological time."

Would it? Cyanobacteria or their alien equivalent would seem to be enough to make oxygen. You don't need macroscopical trees or anything, in fact, those won't appear until after you already have oxygen.

Tony said...

Christopher Phoenix:

"We don't have any FTL physics yet. The limitations of FTL flight will depend on how FTL flight is achieved. There is really no more reason to think that FTL will mean 300,000c or 2c until we have pinned down a method of doing it. I don't see that you have any grounds to assume that FTL means arbitrarily fast, other than wishful thinking. Even if there is no limit to the speed of an FTL ship, there will probably be a limit to the capability of the stardrive."

FTL transport, whatever the means, is an entirely different regime of physics than the inertial one we currently inhabit, by definition. It's not like the speed limit is 35 mph, but we have a fast car that can go 70. There's no inertial world analogue. It's not that I'm declaring by fiat that we should be able to go faster than 2c. I'm saying that there's no reason to expect any inertial world speed limit of any kind, and plenty of reason to suspect that if you aren't limited by inertial considerations, "speed" has no meaning.

"In fiction, it is generally best to put some interesting limits on your FTL drives and see what kind of setting evolves from these constraints."

Yes, but it has to be credible. The old arbitrary linear propagation from here to there at some multiple of lightspeed -- or just as often, so many hours or days per light year -- just isn't particularly credible anymore. That's why FTL in more recent decades has settled into range-limited jump drives or point-to-point technology of some type (usually associated with proximity to large gravitational masses like stars).

Tony said...

Skírnir:

"Essentially what you are saying is, with STL we are constrained by the laws of physics, while for FTL we can ignore them. Well, if it's just that, we can also make up a Reactionless Drive that allows us to go really fast STL without taking propellant with us."

You can make up a reactionless drive, but then you start straining credibility, especially if you base your FTL on wormholes or somesuch that just might barely be possible.

Or your FTL jump drive might require the detonation of a gigaton nuclear device to generate the necessary energy. Now that's something that would make for interesting plot twists, because resources and logistics -- plus the likely limitations on possession and use of such devices -- become a real constraint on FTL travel.

American Kate said...

A shirtsleeve environment planet would need a large and complex ecosystem (with carbon based life) to create an oxygen atmosphere and maintain it over geological time.

As for the creatures that live there, I expect they would make us very sick through allergic reactions to the alien protein analogues (and we them), so I'd go easy on the hunting...


Ah, okay, I thought you talking about a shirtsleeves environment. Sorry about that.

As for the animals. . . I guess that'd depend, if I can breathe the air surely there must be some of the local flora and fauna that I can eat.

Anonymous said...

=Milo=



Tony:

"I'm saying that there's no reason to expect any inertial world speed limit of any kind, and plenty of reason to suspect that if you aren't limited by inertial considerations, "speed" has no meaning."

It might not be "speed" in the sense we're familiar with, but it's still possible to take the distance you want to travel and divide it by the time you spend getting there, in some chosen frame of reference (not very hard since your source and target stars will be in roughly the same frame of reference, relative motion of stars is miniscule compared to the speed of light), and expect to come up with some kind of number.

Warp drives are sufficiently realspacey that the concept of speed is meaningful to them, and hyperspace tends to be (though is not necessarily) written as "analogous" to realspace with similar proportions of distance, so again speed is meaningful.

One way that speed might not be relevant in FTL is if you have a natural wormhole network, in which case how long it takes to get somewhere depends on how the wormholes between here and there happen to be arranged, which may have little to do with realspace topology - it's conceivable that Earth just happens to have a wormhole to Rigel, and Rigel has a wormhole to Canopus, and Canopus has a wormhole to Betelgeuse, and Betelgeuse has a wormhole to Alpha Centauri, and that's the easiest way to get to Alpha Centauri.

Another reason that speed as we might understand it might not be meaningful, is if the relationship between distance and trip duration is nonlinear. (This is not as exotic as it sounds, since even STL travel can work out that way if you can continuously accelerate throughout the trip. In that case time increases only as the square root of distance.)

I'll also note that whatever the speed limit may be, and whether it's a hard physical constraint or an engineering difficulty, it won't be a hard limit. As in, it's not going to be like you can go 299.99 c without difficulty, but trying to go 300.01 c makes your ship explode.



American Kate:

"if I can breathe the air surely there must be some of the local flora and fauna that I can eat."

Air is fairly simple. All we really need is oxygen, a simple molecule with two identical atoms. Nitrogen would be nice to dilute it, but that's not even strictly necessary. Beyond that, we only really need a lack of certain things - namely, anything that would be poisonous to us (mind you, this can include carbon dioxide, in too high concentrations).

Food requires complicated molecules like proteins (made of the 20 amino acids we're familiar with), carbohydrates, vitamins (very specific and uniquely arbitrary molecules that our biochemistry just happens to be designed with), essential fatty acids, and so on.

It's more likely for an alien biosphere to have independently come up with the same simple molecules as us, than to have come up with the same complex molecules as us. For the obvious reasons that the latter has many more alternative options it could have tried, while the former is straightforward and doesn't require any creativity.

So it is actually fairly likely that we will find a planet where we can breathe the air but not eat the food.

Christopher Phoenix said...

Tony:

I'm saying that there's no reason to expect any inertial world speed limit of any kind, and plenty of reason to suspect that if you aren't limited by inertial considerations, "speed" has no meaning.

"Speed" will still have meaning to FTL ships in a general sense. How fast can you reach another star and fly back? How quickly does the Terran Star Empire expand? Computer data is not limited by inertia, but we still speak of the speed of a download.

Strictly speaking, speed doesn't mean much to STL spacecraft either. Spaceships don't have a top speed except for the light-speed limit. And, since objects in space are in motion relative to each other, relative speed and the time it takes to reach a destination are all that really matter.

A rocket is limited by the amount of delta-v it can provide and how fast it can accelerate. It doesn't make much sense to talk about either the "range" or "top speed" of a rocket. The only limitations are the acceleration the engine can provide, the amount of propellent is in the tanks, and how long you care to keep the pedal to the metal.

As for FTL ships- the time of travel depends on how the FTL drive works.

A wormhole is a shortcut, so "speed" doesn't mean much in wormhole travel. It will take no more time to traverse a wormhole whether it leads down the street or too another galaxy. Wormholes are the theoretical physics analogue to the "portals" from various SF works.

A warp drive, on the other hand, can travel at different speeds ranging from sublight to superluminal. An early warp drive might only reach the speed of light, for instance. Later models may go much faster. In this case, we are limited by the amount that our drive can warp space.

Many jump drives are limited by the length of jump or the need to be at certain "jump points". At this point we are just making things up, but our drive will still have a "speed limit" due to drive warm-up and cool-down, limitations on the length of a jump, or the need to use rockets to reach the next jump point. Usually, this works out to some multiple of C.

Skírnir said...

@Tony:
yeah, personally I try to provide my setting with a fast means of transportation that does not involve weapons of mass destruction, because I want private spaceships, tramp freighters and stuff like that. So for me the challenge is to make interstellar travel cheap, but not too cheap, and still keep it somewhat extraordinary and special, while at the same time staying clear of causality problems.
I haven't quite decided on all the details, but basically it's a "Jump" system tied to stellar masses, much like you wrote in your previous post.

@Kate:
"I guess that'd depend, if I can breathe the air surely there must be some of the local flora and fauna that I can eat."

Not necessarily. To pick out just one aspect, there seems to be a 50-50 chance - unless there is some universal bias - that all proteins on one world have the "wrong" chirality. Out proteins here all all in L-configuration, but on a different planet the amino acids may have developed in D-configuration, which at the very least means we can't digest them, and they may even be toxic.

Christopher Phoenix said...

American Kate:

Ah, okay, I thought you talking about a shirtsleeves environment. Sorry about that.

As for the animals. . . I guess that'd depend, if I can breathe the air surely there must be some of the local flora and fauna that I can eat.


I wouldn't count on that. The proteins contained in alien meat will probably not mesh with ours- and these biochemical barriers could be deadly. The meat might not even be nourishing.

From the Wikipedia article on hypothetical types of biochemistry:

Perhaps the least unusual alternative biochemistry would be one with differing chirality of its biomolecules. In known Earth-based life, amino acids are almost universally of the L form and sugars are of the D form. Molecules of opposite chirality have identical chemical properties to their mirrored forms, so life that used D amino acids or L sugars may be possible; molecules of such a chirality, however, would be incompatible with organisms using the opposing chirality molecules. It is questionable, however, whether such a biochemistry would be truly alien; while it is certainly an alternative stereochemistry, molecules that are overwhelmingly found in one enantiomer throughout the vast majority of organisms can nonetheless often be found in another enantiomer in different (often basal) organisms such as in comparisons between members of Archea and other domains, making it an open topic whether an alternative stereochemistry is truly novel.

By the way- I noticed in your profile that one of your favorite books is Jane Eyre. I love Jane Eyre too- there's nothing quite like Gothic romance for a cloudy day. I like the Chronicles of Narnia as well.

Tony said...

Christopher Phoenix:

If you go from here to there in no measurable time, either outside or inside the ship -- which is the case with most notional jump drives -- then there is no such thing as speed of advance.

Rick said...

Welcome to another new commenter!

'Shirtsleeves' turns out to be a rather slippery concept. It is typically used strictly in terms of the physical environment, but if we are allergic to the local life we could get awfully itchy under our shirts.

Of course, absolutely everything about exobiology is about as speculative as you can get. For all we know, all biochemistries may develop along patterns like our own, in which case you could eat the local food, at least in principle. I sort of doubt it, but my knowledge of the relevant sciences is modest in the extreme.

'Speed' in space is also a rather slippery concept. But if an FTL has some fairly consistent relationship between distance and travel time, there is some useful sense in which you can talk about speed.

Compare to 'schedule speed' of any scheduled transport, a useful concept even though it has only a loose relationship to the physical speed of the vehicles.

Christopher Phoenix said...

Tony:

"If you go from here to there in no measurable time, either outside or inside the ship -- which is the case with most notional jump drives -- then there is no such thing as speed of advance."

Strictly speaking, an instantaneous "jump drive" has infinite speed. Practically speaking, limitations on the length of a jump, the drive spin-up and cool-down times, energy requirements, or "jump points" set clear limits on the speed and range of jump drives in SF- mainly so the map still matters in the creator's setting.

Reaching your destination in no time flat is booooriiing, and such jumps will be very problematic for a writer. There won't be space travel in the form we are used too- just star-jump shuttles that fly to whatever distance from a planet you need to be to make a safe jump. Interstellar war will be genocidal affairs that last only about five minutes. Your jump-bombers will pop out, reappear over enemy planets, drop planet-cracker antimatter bombs and return home to find that the enemies bombers were on a similar mission. Beyond that, it is implausible. How could your jump ships know the location of their destination across many dozens of parsecs?

Many writers avoid this problem by postulating "jump points" or requiring the drives to be far away from the gravitational fields of planets and stars to function. The spaceship then needs to use rockets to get from one jump point to another or to climb out of the inner solar system's gravitational field.

However, even a "initiate jump anywhere and reappear several parsecs away" jump drive has challenges for the crew to overcome. How do we make sure we reappear close to the planetary system we want to visit? How can we make sure that we don't jump into an obstacle and collide with something? All our knowledge of the destination solar system is based on decades old light received by our telescopes. We might jump into hazards that we are not aware of. It is highly unlikely that the crew can make a precise jump directly to their destination- they will still take some time traveling through real-space from the point their ship rematerialization point to the destination.

As Rick pointed out, the schedule speed of a transport is not the same as the speed the vehicle travels.

Tony said...

Christopher Phoenix:

I was addressing the pure physics, not the story considerations. Sheesh.

Christopher Phoenix said...

Tony:

"I was addressing the pure physics, not the story considerations. Sheesh."

Several weeks in real-space to reach a jump-point, an instantaneous transference to a distant system, several more weeks reaching another jump point on the other side of that system, an instantaneous jump through to the destination solar system, and several more weeks to reach the destination planet is not instantaneous travel. The ship leaps several light years in under a millisecond once it reached a jump-point, but it has to slog from jump-point to jump-point.

Even a "jump-anywhere-and-reappear-several-parsecs-away" drive has practical limitations. The crew needs to plot out a safe rematerialization point- not an easy thing to do when the ship is jumping into unexplored space. The crew won't be able to jump straight to their destination- they probably aren't sure exactly where it is. Long journeys may be executed in a series of smaller jumps. Maybe there is a limit on the distance of the jump, or the reappearance point becomes more random with distance, whatever- space travel will still consume time.

The real limitation on a jump drive will be the range at which the navigation computer can plot out a safe course. If the coordinates are calculated incorrectly there is danger of colliding with a star, asteroid, or other space debris.

I am discussing the practical limitations on the jump drive's speed-of-transfer. Astrogation, drive power, and safety will probably set clear limits on the range of the jump drive and how quickly the ship can cross interstellar distances. The first exploration ships will have the harrowing task of jumping into space that they have never seen before- with the possibility of colliding with space debris or some other hazard if they aren't careful. Over time, safe jump routes will be found and our ships will jump from world to world on a more routine basis.

I understand your point- the jump drive generally takes no time to reach its destination, thus it has nearly infinite speed- but practically speaking, a jump drive will still take time to reach a faraway planet.

Tony said...

Christopher Phoenix:

Let's come to an understanding here. I've been reading SF for almost forty years. You're not saying anything that hasn't been presented to me numerous times, nor which I haven't considered thoughtfully just as many times. I understand all of it.

So, once again, I was addressing the specific physics of the jump itself, and just the jump alone, not any extrinsic factors or influences. Can we be clear about that?

Anonymous said...

The problem of collisions upon reentry into normal space would be made more complicated if the drive (as discussed in one of the FTL threads) obeys conservation of mass by requiring a mass equal to that of the ship at the destination point to swap places with it (for an instantaneous jump drive), or to form an exit wormhole (for a non-instantaneous 'hyperdrive').
A destination area could not be empty, but could not be so full that a ship would be at risk of collision as soon as it reemerged.

R.C.

Christopher Phoenix said...

"So, once again, I was addressing the specific physics of the jump itself, and just the jump alone, not any extrinsic factors or influences. Can we be clear about that?"

I already said I was clear on that- but I was more interested in the actual trip time of such a ship, not the jump itself.

As for the actual physics of such a jump drive, it would seem to be using something like a transversable wormhole. The drive folds space and punches a hole through, creating a shortcut to a distant part of the galaxy. Strictly speaking, the ship doesn't travel faster-than-light- it just travels at sub-light speeds through a shortcut.

Then again, according to the movie Event Horizon, this might not be a good idea. Liberate tu temet ex inferis!!!!

Can we ever find some means of FTL transport that is both achievable and avoids causality paradoxes? (And doesn't warp us to the depths of hell!?) I don't know, but I intend on studying the physics required to approach these issues.

I'm sorry if I was nit-picking. I still think that being sent to the depths of an infernal, chaotic realm rumored to be the depths of hell will slow down interstellar transport, though!!

Tony said...

Christopher Phoenix:

"I already said I was clear on that- but I was more interested in the actual trip time of such a ship, not the jump itself."

While important, gate-to-gate time encompasses so much stuff outside of flight time that it's almost an entirely separate subject. I was trying to stay focused on the physics, because that's where I saw a problem. (Knowing what we now think we know, a measurable multiple-of-c rate of propagation seems rather naive.)

"As for the actual physics of such a jump drive, it would seem to be using something like a transversable wormhole. The drive folds space and punches a hole through, creating a shortcut to a distant part of the galaxy. Strictly speaking, the ship doesn't travel faster-than-light- it just travels at sub-light speeds through a shortcut."

I'm agnostic about the physics. I'd believe just as much in superposition engines -- if not screwed up by the author with boring and ill-fated attempts at showing his homework -- as I would in wormhole traversals. In that sense I'm very much a story oriented person. Just take it as a given that it works and write a good story around it, thank you very much.

"Can we ever find some means of FTL transport that is both achievable and avoids causality paradoxes? (And doesn't warp us to the depths of hell!?) I don't know, but I intend on studying the physics required to approach these issues."

I for one am fully invested in causality protection. If FTL is indeed possible, my conjecture is that it's going to turn out that we have, up until now, made some rather monumental interpretational errors WRT relativity.

Tony said...

R.C.:

"The problem of collisions upon reentry into normal space would be made more complicated if the drive (as discussed in one of the FTL threads) obeys conservation of mass by requiring a mass equal to that of the ship at the destination point to swap places with it (for an instantaneous jump drive), or to form an exit wormhole (for a non-instantaneous 'hyperdrive').
A destination area could not be empty, but could not be so full that a ship would be at risk of collision as soon as it reemerged."


If we postulate strict energy and mass conservation, then the departure and arrival volumes would be more dangerous to outside observers than to the ship or its passengers. Imagine having your ship cut in half and whisked (probably in the form of a subatomic particle gas) several dozen light years away by an unlucky emergence too close to you. Imagine being in a congested departure area and dealing with several cubic AUs of gas suddenly compressed into the size and shape of the departed vessel's drive field.

Anonymous said...

=Milo=



Tony:

"I was addressing the pure physics, not the story considerations. Sheesh."

"So, once again, I was addressing the specific physics of the jump itself, and just the jump alone, not any extrinsic factors or influences."

So who cares about the physics?

The whole subject of FTL speed came up in the first place because Skirnir and Sean were talking about the effects it has on society and on the logistics of colonization. Those are story considerations.

The underlying physics is something that only stardrive engineers will care about. Everyone else is going to be timing the journey as a whole.



Christopher Phoenix:

"Can we ever find some means of FTL transport that is both achievable and avoids causality paradoxes?"

Avoiding causality paradoxes is easily - all you need is a preferred frame of reference, which is by no means implausible, since one preferred frame of reference is already known to science today, and nothing about special or general relativity explicitly outrules us someday discovering another.

As for achievable, I'll have to get back to you on that in a few hundred years...



Tony:

"In that sense I'm very much a story oriented person."

Guess what, so are we.

Christopher Phoenix said...

Tony:

You're quite right- having an interesting story to tell matters more than making up fancy drives and fictional physics.

"The problem of collisions upon reentry into normal space would be made more complicated if the drive (as discussed in one of the FTL threads) obeys conservation of mass by requiring a mass equal to that of the ship at the destination point to swap places with it (for an instantaneous jump drive), or to form an exit wormhole (for a non-instantaneous 'hyperdrive').
A destination area could not be empty, but could not be so full that a ship would be at risk of collision as soon as it reemerged."


I'm don't quite understand how conservation of mass would demand that a mass equal to that of the ship swap places with it during a jump. The same amount of mass is still present in the universe after the ship has rematerialized- it is just in a different part of the galaxy.

I'm also not clear on how a wormhole forming would become a catastrophic event. All I'd expect to see would be a "window" to open up through which I could see a distant part of the galaxy.

As for causality- most physicists feel the same way as you. There are other concepts for keeping time travel paradoxes form occurring even with time machines- like the Novikov self-consistency conjecture, but these are still speculation. If it turns out FTL is possible but time travel does not result from such trips, then our understanding of relativity is flawed.

If we ever did create time machines, FTL travel would be included in the bargain. All our interstellar travel methods depend on manipulating the equation D=VxT. Most of our ideas increase V. But if we can manipulate T, then we can reach our destination any time we like...

In the original Star Trek pilot, The Cage, the characters refer to there engine as a hyperdrive and as a time warp drive on separate occasions. It is stated that the "time barrier" has been broken. Perhaps that means that the ship manipulates the flow of time to achieve FTL travel, perhaps jumping backwards in time as it flies forward, so very little time seems to have elapsed during its journey.

Here is an annoying idea. The faster a hyperdrive equipped ship travels, the more time elapses for the crew- a sort of reverse time dilation. The crew has to go into suspended animation to travel at FTL speeds. Perhaps the "time barrier" being broken would mean some means of compensation for the time elongation effect, allowing the crew to dash a great distance across the galaxy without dying of old age in hyperspace...

Anonymous said...

=Milo=



Christopher Phoenix:

"If it turns out FTL is possible but time travel does not result from such trips, then our understanding of relativity is flawed."

Nope. All you need is a preferred frame of reference, and relativity does not outrule the existance of one, only state that it doesn't know of one. (No big deal, relativity also doesn't know about quantum mechanics.)


"If we ever did create time machines, FTL travel would be included in the bargain."

If we have time machines, we can implicitly get "FTL" by travelling somewhere slower than light, than hopping back in time once we arrive. However, this would only be FTL by the standards of those outside the ship. By the standards of those inside the ship, the trip still took as long as it would have without time travel.

Fortunately, in theory we can still make travel time as perceived by those inside the ship arbitrarily short, using time dilation. Unfortunately, reaching the speeds necessary for this is absurdly difficult, even with antimatter rockets, and the trip will still take a minimum of several years unless you also have "inertial compensators" to eliminate the limitation of not being able to accelerate much faster than 1 g.

Another approach would be putting people in cold sleep for the duration of the trip. This requires making your cold sleep machines reliable over hundreds of years, when we haven't gotten cold sleep to work at all yet, but it breaks the known laws of physics less than time travel, inertial compensators, or better-than-antimatter energy sources.

Anonymous said...

Christopher Phoenix:

To be honest, I'm not completely sure why the mass swap is necessary either, but Luke and Raymond (I think; the thread in question is a bit too long to look through easily) mentioned the issue in an earlier thread talking about FTL, and I trust them to know what they're talking about.

As for the dangers of wormholes, Luke and/or Raymond suggested that for a non-instantaneous hyperdrive, the ship would open a wormhole to 'hyperspace', then fly into it. The wormhole would take on the ship's mass, and once the ship had entered hyperspace, would quickly and explosively evaporate in a flash of radiation, like a micro black hole. Since a single gram of mass has the energy of a 21.5 kiloton nuclear bomb, and the wormhole would have the hundreds or thousands of tons of mass of the ship that flew into it, the resulting energy might be lethal to ships and habitats even thousands of kilometres away.

At the destination end, the wormhole would draw in mass from around it until it became equal to the mass of the ship, which would allow the ship to emerge from hyperspace. This could be dangerous if other ships or habitats were too close, since they and the wormhole would be drawn towards each other, risking damage or destruction to both parties.

R.C.

Tony said...

Mass exchange for jump drives is rather an arbitrary constraint, but it's at least plausible as a conservation mechanism.

WRT wormhole side effects, consideringthe energy that it's supposed to take to open one, the danger to bystanders upon collapse would probably be real enough.

I'm not convinced the amount of energy a jump drive consumes corresponds to range. I think it much more likely that the ability to see what's at the other end would be much more of a constraint. That means one would only jump several light years (or several hundred) into interstellar space, then use instrumentation to examine the target system from a few light months out to find empty space into which one might jump.

Christopher Phoenix said...

I'm not so sure that Luke and Raymond know what they're talking about, but then again I am not an expert on wormhole physics either. I have caught mistakes in serious online discussions between SF fans on topics that I do have more knowledge of occasionally.

Frankly, this "wormhole gaining the ship's mass and then exploding" sounds like technobabble. It might be based on the idea that if the ship travels outside of this continuum, conservation laws demand the same amount of mass/energy has to come from the "other" continuum to take its place. I saw mention of this on a website that was discussing the scientific issues of phaser weapons in Star Trek, specifically a phaser's ability to disintegrate matter in a flash of light on higher power settings. I have never seen Mark Millis, Michio Kaku, or Carl Sagan discuss any of these sort of issues with wormholes.

I think that if hyperspace exists, it is an extension of our four-dimensional universe. Flying through it should not be a major problem for conservation laws, since the ship is just taking a shortcut through a part of our universe we don't normally perceive. I don't see why wormholes would have these issues either. Maybe I'm wrong, but it still sounds like a made-up constraint and not a consequence of a real scientific theory.

As I understand it, hyperspace in physics and fictional hyperspace are somewhat different. Some scientists have touched on the idea that we might be able to create shortcuts through higher dimensions, but it seems rather unlikely. If a hyperspace drive did work, it might be like the hyperdrive from Isaac Asimov's Foundation series- the ship vanishes and reappears instantly somewhere else. Extra spatial dimensions are said to be tightly curled up, so the drive would have to somehow enlarge these extra dimensions.

I always preferred star-drives to wormholes and stargates. Not that I wouldn't like to step through a stargate, but it lacks the romance of a starship.

Christopher Phoenix said...

I like teleport drives and stutterwarps. This drive teleports the starship one shiplength millions of times per second, allowing it to reach high sub-light speeds or even superluminal speeds without actually accelerating. This lets you dodge those two annoying things called "inertia" and "the light-speed barrier", all without needing to travel through wormholes or hyperspace.

This drive is based on a form of teleportation that actually moves particle through space- not something like quantum teleportation that only moves information. Energy and momentum are stilled conserved by this form of teleportation, so teleporting up will cause you to lose energy and become colder- that or the teleportation machine will need more energy. If you teleport from the equator to New York City, you will slam into the wall due to your excess momentum.

The effects of a stutterwarp are rather odd and counterintuitive. Remember that the starship is not "moving", it is jumping a short distance millions of times per second, creating the illusion of movement- similar to a movie playing. You stay in real-space the whole time, so you see the stars flash on past, even the ones behind you. You literally jump into the light of the stars behind you, so you can still see them. If light does not teleport with the ship, you get some odd visual effects. When you stop the drive, the ship stops immediately and retains whatever momentum it had before the ship began its journey. The crew might experience adverse health effects due to the ship "telefragging" interstellar dust into their bodies- a slightly alarming prospect.

You can even fire a rocket in the opposite direction to the one your ship is traveling. If your drive encounters space debris, the stutterwarp will shut off and your starship will fly away in the opposite direction with all the momentum it built up while in superluminal flight. You still need rockets to land on planets when you reach them, since the teleport drive can't match speeds with a planet to land.

Tony said...

Christopher Phoenix:

A bit of friendly advice: don't spend all of that time rephrasing Atomic Rockets. Just mention things by their common name (e.g. "hyperdrive" or "stutterwarp"). If somebody doesn't know what you're talking about, they'll let ya know. Then you can make your explanation. People here tend to bei nterested in what you have to say about things, not in how well you can describe them.

Like I said, that's friendly advice. Take it FWIW.

Now, I'm wholly agnostic about how a wormhole/jump FTL scheme might work. The point I was making is that mass exchange is at least plausible as a plot point, even if it may not turn out to be a real world (for certain values of "real") issue. Likewise, since it must take lots of energy to open up a wormhole -- else we'd see them and their effects in our everyday lives -- it seems at least as plausible that side effects of that energy use in a concentrated space might be dangerous.

I tend to find jump type FTL more plausible than measurable distance-per-time propagation because with string theory we surmise that the extra six or seven space dimensions are rolled up into supermicroscopic size. In one interpretation that means the whole universe in those dimensions exists in every almost dimensionless point of 3D space around you. It shouldn't take any measurable time at all to go from one end of the universe to the other, through a "hyperspace" (the old Golden Age SF term "subspace" seems much more appropriate) made up of these dimensions.

Anonymous said...

=Milo=



I won't claim to understand string theory very well, or at all, but I always understood those "supermicroscopic" dimensions as being something like a sheet of paper - which is a three-dimensional object with two dimensions that are much larger than the third. But while this means it would take nearly no time to travel across the third dimension, this wouldn't let you instantaneously move to the other side of the page according to the first two dimensions.

Skírnir said...

>"It shouldn't take any measurable time at all to go from one end of the universe to the other"

This is pretty unorthodox as SF goes. Whether the jump takes measurable time or not, there usually are economic constraints. Note that I am approaching from an "author's angle" again rather than scientific: It's typically more expensive to jump with fat heavy ships than with light ones, and usually also longer distances are more expensive than short ones. I think this should apply especially when you use an instantaneous jump model.

Question is, what would be a plausible / believable mechanism to determine the cost of a jump wrt ship mass and distance?

Tony said...

Skírnir:

"This is pretty unorthodox as SF goes."

It is? See Dickson's Dorsai series (AKA "Childe Cycle"), where the FTL drive is explicitly explained as expanding the spaceship across the entire breadth of the universe, then recompressed at the intended destination. This was first published in 1959.

WRT point-to-point jumps, authors often say that the jumps take either zero or a finite but immeasurable small amount of time. This pretty much corresponds with crossing the universe in zero or near zero time, as far as the speed of propagation is concerned, whatever other limits the author chooses to insert by hand for the purposes of story flow.

Stutterwarp drives, if you think about it, rely on essentially the same kind of infinite propagation speed jumping, even if (once again, for story purposes) range limited to a few light seconds per atomic (in the sense of being indvisible, not size) jump.

Inifinite or ultra-high finite speed jumping about the cosmos is one of the most orthodox things in SF. Authors just wrap all sorts of balls and chains around it in order to save stories from being unamageable (and maybe even un-imaginable).

"It's typically more expensive to jump with fat heavy ships than with light ones, and usually also longer distances are more expensive than short ones."

Where? In some ill-imagined RPG? I've never seen a jump drive in serious SF that was made more expensive by vehicle size. Usually, if there is a size constraint, it is that one must have a very large vehicle to carry the power generation systems to power a jump. This often leads to a very large jump "bus" type of interstellar spacecraft that carries smaller -- but still large -- interplanetary craft between systems.

Another type of limitation that leads to large jump type interstellar spacecraft is a limitation on qualified navigation personnel, usually telepathic or at least clairvoyant. This also leads to large carrier jumpcraft. See the heighliners in Dune for the prototypical example.

"Question is, what would be a plausible / believable mechanism to determine the cost of a jump wrt ship mass and distance?"

See above. Larger ships should be more efficient than small ones, all other things being equal. One might choose to use smaller, less efficient ships if one has military or commercial priorities that override cost minimization.

Anonymous said...

=Milo=



Skirnir:

"It's typically more expensive to jump with fat heavy ships than with light ones, and usually also longer distances are more expensive than short ones."

Is it? The prevalence of "space fighter carriers" (bear with me here) and other motherships suggests that in a typical SF world, tactical mobility is easier for lighter ships, but interstellar travel works better (or only works at all) with heavy ships.

Christopher Phoenix said...

Thanks for the advice, Tony- but I wasn't paraphrasing atomic rockets. I first read about teleport drives at Orbital Vector.

If we want "realistic" starships, then we can describe sub-light star travel. There is nothing in the laws of physics that prevents us from building our first starships sometime in the next few centuries. We might build vast laser arrays on the Moon to push light-sail craft on long journeys to other stars. Or maybe we will use high-isp rockets like ion drives, antimatter rockets, or photon drives to propel our early starships on their long journeys.

If we are really lucky, maybe discoveries in physics will lead to the invention of a propellentless space drive. Control over gravitational and inertial forces could lead to something like this. Continued advances in space drive physics and energy conversion will lead to faster and faster starflight.

We'd all like to discover FTL flight, but even the most serious minded proposals toward that idea are speculative at best....

On the jump drives- I'd imagine that bigger ships can carry the power generators and jump drive more easily than a smaller craft. Maybe only big starships can carry jump drives. In that case, huge star-carriers will shuttle smaller ships from star to star.

I can imagine a type of star travel that would place a size limit on the spacecraft that can use it. Ships larger than the mouth of a wormhole won't be able to travel through it. Unless the ship can break up into smaller modules and pass through piece by piece, it won't be able to use the wormhole network. In this setting, interstellar shuttles will be small rather than huge.

Anonymous said...

=Milo=



Christopher Phoenix:

"I can imagine a type of star travel that would place a size limit on the spacecraft that can use it. Ships larger than the mouth of a wormhole won't be able to travel through it. Unless the ship can break up into smaller modules and pass through piece by piece, it won't be able to use the wormhole network. In this setting, interstellar shuttles will be small rather than huge."

Or long but thin. Like... worms.

Christopher Phoenix said...

Milo:

"Nope. All you need is a preferred frame of reference, and relativity does not outrule the existance of one, only state that it doesn't know of one. (No big deal, relativity also doesn't know about quantum mechanics.)"

You are rather hopeful- but you are unfortunately in error. Special Relativity is based on one simple concept- that the laws of physics are the same in all reference frames. If there is a preferred reference frame, then the laws of physics are "simpler" in the reference frame. There is no preferred reference frame in either Newtonian Mechanics or Special Relativity.

The search for a preferred frame for FTL travel is basically a search for an FTL "ether". As SF fans, we obviously have a great desire to find FTL travel- but the universe does not have to be a certain way because SF fans think it would be "cool". What you're saying, basically, is that inventing new physics is fun and easy. I'm afraid not.

Ever heard the saying, "Relativity, Causality, and FTL travel; pick any two?". If finding a preferred frame of reference was so "easy", than the likes of Mark Millis wouldn't be so distressed about causality paradoxes ruining their schemes for FTL travel.

So what is this preferred frame of reference we know about today? I certainly haven't heard of it in any of my science textbooks.

I'm not saying that we might not find such a preferred frame of reference. It will show that Special Relativity isn't completely correct if we do. If you read through Atomic Rockets, you'll not such a preferred frame can resolve the causality paradoxes associated with FTL travel and allow for intertialess thrusters. So, all you need to do is butcher Einstein to get what you want...

And don't forget to bash that meany Newton too. He won't let us have our inertialess thrusters!! :' (

The Breakthrough Propulsion Physics project looked through some of the ideas relating to FTL travel and space drives. The big problem with a space drive is finding some means of maintaining the conservation of Momentum and having your propellentless space drive at the same time.

Tony said...

Christopher Phoenix:

"Thanks for the advice, Tony- but I wasn't paraphrasing atomic rockets. I first read about teleport drives at Orbital Vector."

You're welcome. FYI, a lot of what you wrote sounded like it came from the Atomic Rockets "FTL" page. But AR draws form everywhere, so...

"If we want "realistic" starships, then we can describe sub-light star travel."

IMO, these are just as speculative as FTL, given the energies involved to get anywhere in a humanly reasonable amount of time.

"On the jump drives- I'd imagine that bigger ships can carry the power generators and jump drive more easily than a smaller craft. Maybe only big starships can carry jump drives. In that case, huge star-carriers will shuttle smaller ships from star to star."

That's definitely my take. But I can see how a lot of SF readers don't like that, because it eliminates a lot of favorite tropes like tramp star traders, scout ships, etc. Also, it empowers governments and megacorps, which a lot of SF readers really hate (whether for good or bad reasons I'll leave up to the reader).

Of course, if you apply enough bafflegab, the readers might not even notice what you're doing. In Dune, for example, the Spacing Guild is essentially a civilization-wide megacorp that controls interstellar travel to the point that both governments and smugglers have to put up with their BS, and which treats both governments and smugglers equally, for the correct price. But cover it up in mysticism and justify it with a (totally arbitrary, even in-universe) resource limitation, and the readers just eat it up.

(If you think I think this is a comment on SF readership, you would be 100% correct.)

"I can imagine a type of star travel that would place a size limit on the spacecraft that can use it. Ships larger than the mouth of a wormhole won't be able to travel through it. Unless the ship can break up into smaller modules and pass through piece by piece, it won't be able to use the wormhole network. In this setting, interstellar shuttles will be small rather than huge."

It would make wormholes more like transhipment stations in the old railroad days where guages on two different lines were incompatible, or cargoes had to be ferried across rivers where no railroad bridge existed. Strategically, this would make interstellar warfare a bit of a mess, because you would have to move all logistics breakbulk, and you could only shift major fleet units that could be modularized. Also, imagine coming through the wormhole in frigates, then having to fight battleships.

Thucydides said...

Size/power relationships would probably exist with wormhole type drives, with the diameter of the wormhole being one of the limiting factors. If true, then ships would either be long, narrow needles, or be arranged to fold up into compact shapes to enter the wormhole at the minimum practical diameter.

Since one of the other issues was identifying potential dangers at the exit point, the wormhole could be opened at narrow diameter for the crew to "boresight" the target and check for potential issues (space debris, pirates, the wormhole exit is in the center of a star...) before expanding it to ship size and making the jump. In that case, the only limit to distance is how far the wormhole ends are "projected.

Tony said...

I think wormholes in the traditional sense would have to be constructed with both mouths in the same factory, so that stabilization gear could be attached to each one. Then one mouth would be taken STL to the intended destination system and placed in orbit, probably at the L4 or L5 point of the most interesting planet.

With the exception of point-to-point drives that take advantage of existing flaws in spacetime, jump drives would be blind. Jump destinations would have to be into relatively empty interstellar space, for the most part, with careful approaches made to destination star system. One would use sophisticated survey gear and a lot of ballistic calculating to figure out where dangerous stuff is going to be when you jump deep into an uncharted system. Even with charted systems there would probably be preferred approach "lanes" (actually orbital positions known to be free of natural or artificial debris) and traffic control.

Tony said...

WRT special frames of reference, they've long been a staple of both STL anf FTL in SF. What does it mean for a non-rocket (I won't say "reactionless") thruster to push against the "fabric of the universe", except that a special frame exists against which to push?

Also Milo is right that general relativity and quantum mechanics have not been reconciled. So there may be some wiggle room in there for a special frame or frames linking the two. But then special relativity says "no". Uhhh...Houston we have a consistency problem.

Additionally, the Newtonian straight line propagation of light in effect demands a special reference frame where massless particles are not effected by gravity, while massy ones are. Today we would say that is an abstraction that seemed like a reality because measurements weren't precise enough.

Okay, what if a frame or frames exist in which all four of the dimensions of normal space are embedded? It may be very true that within four dimensional space everything id frame-invariant, and has to be. But on the scale of the larger frames...who knows?

Anonymous said...

=Milo=



Christopher Phoenix:

"Special Relativity is based on one simple concept- that the laws of physics are the same in all reference frames. If there is a preferred reference frame, then the laws of physics are "simpler" in the reference frame."

Nope. The laws of physics that special relativity describes are the same in all reference frames. There are laws of physics beyond those described by special (or general) relativity.


"There is no preferred reference frame in either Newtonian Mechanics or Special Relativity."

So, like I said, Newtonian mechanics and relativity don't know of a preferred preference frame. That doesn't mean other physical theories don't, since relativity does not describe everything in the universe and does not claim to.


"Ever heard the saying, "Relativity, Causality, and FTL travel; pick any two?"."

Yes, I have. I am simply disagreeing with it.

The correctness of a statement is not necessarily proportional with how pithily you are stating it.


"So what is this preferred frame of reference we know about today? I certainly haven't heard of it in any of my science textbooks."

Here you go: comoving coordinates. They're defined in the context of Big Bang theory, and are measurably evidenced in real life as the frame of cosmic microwave background radiation. Their validity is further reinforced by the observation that the vast majority of the mass in the universe has a relatively low velocity (less than 1% of the speed of light) relatively to the comoving rest frame, called the "peculiar velocity".

One caveat is that comoving coordinates are not exactly a frame as understood by relativity. Rather, they are a sort of "curved" frame that has a different normal/flat frame tangent to it at every point. Regardless, it suffices for the desired purpose of defining an absolute sense of future/past for events that are spacelike with respect to each other.

And of course, I only demonstrated the existance of a preferred frame of reference, not proposed a mechanism for an FTL drive that takes advantage of it. However, you did not ask me to, nor did I claim to be able to.


"If finding a preferred frame of reference was so "easy", than the likes of Mark Millis wouldn't be so distressed about causality paradoxes ruining their schemes for FTL travel."

I just found a preferred frame of reference, so it must be pretty easy. (To be fair, anything is easy once other people did the hard work.) So, I have to conclude that Mark Millis is distressed because he is misinformed. Some people avoid the most obvious pseudoscience traps, only to fall into the less obvious traps hidden immediately behind them.


"It will show that Special Relativity isn't completely correct if we do."

It already isn't completely correct. Like I said, quantum mechanics.

Newtonian mechanics also isn't completely correct, but it's still approximately correct and applicable to a great many real-life situations.


"If you read through Atomic Rockets, you'll not such a preferred frame can resolve the causality paradoxes associated with FTL travel and allow for intertialess thrusters."

Atomic Rockets is wrong too. It contains a lot of useful information, but it is not an absolute authority.

Anonymous said...

=Milo=



Thucydides:

"Size/power relationships would probably exist with wormhole type drives, with the diameter of the wormhole being one of the limiting factors."

If the wormhole generator is onboard the ship, then we can apply the square-cube law. At least, assuming that the surface area of the wormhole is proportional to the energy which is proportional to the volume/mass of the wormhole generator, and that this generator occupies a given percentage of a ship - by no means a guarantee, but a reasonable supposition for SF purposes. In this case ship cross-section diameter is proportional to the cube root of the generator mass, while the wormhole diameter is proportional to the square root of the generator mass. Thus, as you scale the ship up, the wormhole it can create will scale faster than the size of the ship itself, so bigger ships have an easier time.

Of course, this is just one assumption you could make, among many conflicting ones.

Skírnir said...

@Tony:

1. re "instantaneously anywhere", I don't know the story you mentioned, but it also is used in the good old Hitchhiker's Guide, which of course is rather mock SF.

2. re cost, you mainly find that wherever resources are meant to be a factor. That is often the case in games, but they don't need to be ill-written. ;)
And yes, you are completely right, it usually requires a big ship to accomodate a jump drive, I glossed over that part.
One example that comes to mind is the Frontier series (1993 vintage). Alright, these jump drives are not instantaneous, but each jump takes several days (up to a week), but this is also part of the game concept. The range is limited by drive class and tonnage, and the fuel requirement scales by the same parameters. Higher class drives eat more mass. While fuel as such is dirt cheap, it is an economic factor because it eats up your cargo capacity (Frontier ships aren't modular, you can only take along whatever you can cram into the hull - this may be rationalized by the nature of hyperspace in this setting).

This has some interesting consequences for the game:
- if you build the biggest possible drive into your ship, you can jump very far in one go, or do shorter jumps in a very short time.
- if you pursue another ship with a lower maximum jump range, you can actually overtake it in hyperspace, arrive at the destination first, and ambush your quarry there.
- however, with a big drive you have little room left for weapons, equipment or cargo, so usually it's best to stick to the "recommended" drive size.

So that's just one example where economy is a factor in FTL. In literature, economy is often ignored. Personally I find this a pity, I'd be interested in stories about, say, a tramp freighter that has to figure out how to do its cargo runs profitably.

Even without the economy factor, I think the concept of overtaking a ship in hyperspace has potential - but this requires the jumps to take considerably longer than the blink of an eye.

jollyreaper said...


Of course, if you apply enough bafflegab, the readers might not even notice what you're doing. In Dune, for example, the Spacing Guild is essentially a civilization-wide megacorp that controls interstellar travel to the point that both governments and smugglers have to put up with their BS, and which treats both governments and smugglers equally, for the correct price. But cover it up in mysticism and justify it with a (totally arbitrary, even in-universe) resource limitation, and the readers just eat it up.


The Spacing Guild was not any kind of solution or ideal being proposed by Herbert. He was simply trying to create an interesting power structure to tell stories with. He's not advocating for it any more than Tolkien was advocating for dark lords with rings of power. Fans are not going squee over the idea of a giant corporate monopoly. The whole point was the presentation of a massive power tripod -- guild, noble houses, emperor -- all tied together by spice. It stood for so long it seemed as permanent as a mountain. Paul's coming turned everything upside down and then smashed it to atoms.

jollyreaper said...


With the exception of point-to-point drives that take advantage of existing flaws in spacetime, jump drives would be blind. Jump destinations would have to be into relatively empty interstellar space, for the most part, with careful approaches made to destination star system. One would use sophisticated survey gear and a lot of ballistic calculating to figure out where dangerous stuff is going to be when you jump deep into an uncharted system. Even with charted systems there would probably be preferred approach "lanes" (actually orbital positions known to be free of natural or artificial debris) and traffic control.


The thing that's never described with teleportation drives is what happens when there's something in the way. Would it be an atom-splitting boom or just nullification of the matter at the other end? I guess it would have to be nullification or else the whole thing would be impractical. What would be the likely results of a ship the size of the Enterprise appearing in a volume of interplantetary space with the average count of random atoms if those atoms exploded bits of the ship with atom-splitting force? What are the odds that the stray micro-meteor might be around? Could we expect ships of the future to have all that stuff completely mapped out, a perfect model of the target system stored in the navigation computer, unexplored systems get unmanned ships sent in risking explosions until things have been surveyed?

If it's nullification then ships aren't that dangerous and the question is how much decay it would have through time as the ship loses atoms here and there with each jump. But if it's annihilation instead, a ship is a pretty spectacular WMD. Jump it a kilometer above a city and get a boom that would probably dwarf the Tsar Bomba. Any target with a known location becomes vulnerable to attack so nothing truly important could be stored on planets or stations, all the political seats of power with important people would have to remain hidden in interstellar space and remain mobile to prevent the location from being discovered.

In the real world all of our cities are vulnerable and could be destroyed with a nuke at any moment but ICBM's are expensive and controlled by (presumably) rational actors. But unless starships are as tightly controlled as strategic weapons systems, the chance of someone using them in a terror attack is high, even if it's a hijack situation like 9-11. There's only so much damage you can do with even a jumbo-jet but it's a different story if you weren't taking out a single building with one but a city or a continent.

Tony said...

Skírnir:

"1. re "instantaneously anywhere", I don't know the story you mentioned, but it also is used in the good old Hitchhiker's Guide, which of course is rather mock SF."

One must needs weep for how poorly read SF readers are these days...

Nothing personal, Skir -- I'm just increasingly saddened the more and more I see "I haven't read..." referring to books and stories that were considered basic equipment 20 years ago.

"One example that comes to mind is the Frontier series..."

I guess I should have been more explicit. Games are not SF. They may contain SF tropes and concepts, but IME games are written by casual (at best) SF readers for casual SF readers or scifi TV fans.

"So that's just one example where economy is a factor in FTL. In literature, economy is often ignored..."

No it isn't, not in good SF literature. There just hasn't been much of that written recently, and most kids these days haven't read any good stuff from the past.

"Even without the economy factor, I think the concept of overtaking a ship in hyperspace has potential - but this requires the jumps to take considerably longer than the blink of an eye."

Overtaking a ship in hyperspace is dreck, and always has been. Overtaking and matching jump frequency with a stutterwarp drive ship was a common plot device in Poul Anderson's Polysotechnic League/Terran Empire canon. Joseph P. Martino wrote a novellete for Analog back in the late Sixties involving the detection, pursuit, and attack of stutterwarp ships.

Tony said...

jollyreaper:

"The Spacing Guild was not any kind of solution or ideal being proposed by Herbert. He was simply trying to create an interesting power structure to tell stories with. He's not advocating for it any more than Tolkien was advocating for dark lords with rings of power. Fans are not going squee over the idea of a giant corporate monopoly. The whole point was the presentation of a massive power tripod -- guild, noble houses, emperor -- all tied together by spice. It stood for so long it seemed as permanent as a mountain. Paul's coming turned everything upside down and then smashed it to atoms."

Yes, Herbert definitely applied sufficient bafflegab. Whether he called it a megacorporation or not, that's what the Guild was, and Herbert knew it. I suppose one could make the argument that the guild was collectively villainous, or at least a cancer that had to be irradicated. But the Guild and its monopoly was never put down, because when Paul and the Fremen became the new power structure, they needed the Guild to cary the jihad to the farthest star. Subsequently, Leto II as God Emperor used his control of the Guild to enforce stasis on civilization for thousands of years. Of course it's all supposed to be in the name of preparing the human race to break out from such regimes, but while it's going on it demonstrates the unassailability of such power structures, sensibly managed.

Anonymous said...

<<"It's typically more expensive to jump with fat heavy ships than with light ones, and usually also longer distances are more expensive than short ones.">>

I'm catching up (inventory at work), and when I read this I had a vision of the crew of a starship franticly trying to shovel enough coins into their "Warp-o-Matic" in order to get it to power up before the enemy battlecruiser gets into range to vaporize them...

I need to finish my coffee...

Ferrell

Anonymous said...

Tony, Jollyreaper; Herbert's Guild always struck me as more of a long-term psudo-religious scam rather than a megacorp, but thats just me.

Ferrell

Tony said...

Ferrel:

"Tony, Jollyreaper; Herbert's Guild always struck me as more of a long-term psudo-religious scam rather than a megacorp, but thats just me."

The Guild had a lot of mystique surrounding it, especially where its proprietary navigation "process" was concerned. But it did provide a real service that only it could provide under the circumstances. As long as society insisted on the proscription against "thinking machines" (i.e. computers) the Guild navigators were the only people who could guarantee safe and reliable interstellar communications.

Geoffrey S H said...

"I'm catching up (inventory at work), and when I read this I had a vision of the crew of a starship franticly trying to shovel enough coins into their "Warp-o-Matic" in order to get it to power up before the enemy battlecruiser gets into range to vaporize them..."

I'm willing to bet that Futurama already did that. ;)

Thucydides said...

The guild struck me as something analogous to the "Knights Templar", who provided a service (escorting pilgrims to the Holy Land), and expanded into all kinds of commercial and support activities under a religious charter.

The analogy isn't exact of course, and perhaps better examples can be cited.

jollyreaper said...


Tony, Jollyreaper; Herbert's Guild always struck me as more of a long-term psudo-religious scam rather than a megacorp, but thats just me.


Throughout most of human history we've had mysticism. Science has given us a new way of looking at things and I think has some very compelling things to say that should dissipate a lot of mysticism. Doesn't seem to be the case. If anything, we've seen a trend of technology applied to promoting mysticism. The very existence of the word "televangelist" causes my brain to cramp, just like the first time I saw a program for doing astrological charts. There's just something obscene about using the great tools produced by rational thought to spread ignorance.

But I do wonder at the potential for wedding the tools of science to the promotion of superstition. There were some pretty radical tracts written by Islamic clerics condemning western consumerism and loose morals that advocated using the tools of the west to destroy it. This goes far beyond the simple examples of loudspeakers used to broadcast calls to prayer, holy warriors carrying firearms instead of swords, using international banks to move funds.

I think what we saw in Dune was a successful melding of science and mysticism into a new and fantastically effective power structure. Now you could argue that even going back into biblical times that we had learned skills and they could of course be turned to supporting the power structure. Swords didn't grow on trees; people had to learn how to make them and they were used by rulers to enforce their laws. But science has helped to magnify the impact of modern rulers. We had genocides in history (the Mongols weren't slouches) but the Holocaust really brought it to a new level.

The Nazis pursued a lot of woo science that couldn't possibly work. But what happens when ideas are evil but also feasible? At this point in time the idea of full-on mind control and brainwashing is considered to be woo but we see that religion has stumbled upon some pretty good tools for keeping people in line. The Nazis were pretty damn effective with their propaganda. Just how effective could a weaponized religion be?

That's the idea I keep coming back to. Intelligent design applied to religion, latest psychological techniques applied to make it compelling and controlling.

jollyreaper said...


The Guild had a lot of mystique surrounding it, especially where its proprietary navigation "process" was concerned. But it did provide a real service that only it could provide under the circumstances. As long as society insisted on the proscription against "thinking machines" (i.e. computers) the Guild navigators were the only people who could guarantee safe and reliable interstellar communications.


Doubtless they provided a service but they also had a vested interest in keeping thinking machines banned to maintain their monopoly. So the question is how much they do to support the prevailing cultural views. "Drink Ovaltine!" De Beers promoting the whole diamond ring thing.

Also remember OPEC pumping gas in the 80's because they saw what the embargo did in the 70's -- spurred interest in alternative energy resources. They wanted to keep the price low enough to make alternatives not worth the effort.

As far as the Dune universe is concerned, the supernatural isn't supposed to exist. There are no gods or ghosts, spirits, or magic. What we from our perspective would consider supernatural is just science they've figured out. So the other memories of the Reverend Mothers has a scientific explanation. Same with genetic memory in gholas and the superhuman mental conditioning, combat training, etc. There's supposed to be a rational scientific explanation for all of it that might appear magical to people of our time, the same way xrays and radio waves and nuclear physics would baffle people hundreds of years ago.

jollyreaper said...


The guild struck me as something analogous to the "Knights Templar", who provided a service (escorting pilgrims to the Holy Land), and expanded into all kinds of commercial and support activities under a religious charter.

The analogy isn't exact of course, and perhaps better examples can be cited.


What I like about it is analogy never quite works. As far as big human organizations we've pretty much had tribes, kingdoms, empires, all variations of the idea of a state. Whoever can bash in enough heads gets to have a state. The Catholic Church transcended all of that and was a power that no prince could himself control. While priesthoods had power in times past and within a state there could be any number of competing factions to threaten a ruler, I would tend to think that the scope and power of the Christian Church was unusual. Could be wrong on that.

Nation-states eventually became the dominant political form but seem to be at the point of being transcended by multi-national corporations. The way governments are acting these days, they seem like client-states of the financiers calling the shots. Corporations are wearing the pants in this relationship.

I always find it interesting where you think you have a handle on what's going on at first glance, who's calling the shots, who's taking orders, and then you find out that it's a lot more complicated than you think. The king is not the master of his domain.

Thucydides said...

I think the nation state will be around for quite some time to come. The reason we have nation states is pretty brutal and straight forward; they can raise and organize resources better than any competing organization (and that included the Church, guilds, city states, trade federations and a host of other organizations and models that existed in the late middle ages). The key thing nation states excel at is organizing and using military forces. The argument was pretty decisively settled by the 30 years war and the Treaty of Westphalia.

Even modern day mercenary forces like "Blackwater" or "Executive Outcomes" simply could not exist without an existing nation state to provide the secure and stable conditions to raise train and equip such forces (and woe betide any corporate force that runs afoul of the USMC).

Condottieri may make an appearance in the future when humans are scattered in small, widely spread colonies. The force to space ratios will be ridiculous, and colonies will preferentially want to conserve wealth and resources rather than invest in standing military forces. Even this state of affairs will only exist so long as resources are limited, force to space ratios are huge and no one power decides to emerge and challenge the status quo. (Humans, being what we are, will still find things to fight about so long as we are human).

Mangaka2170 said...

"Condottieri may make an appearance in the future when humans are scattered in small, widely spread colonies. The force to space ratios will be ridiculous, and colonies will preferentially want to conserve wealth and resources rather than invest in standing military forces. Even this state of affairs will only exist so long as resources are limited, force to space ratios are huge and no one power decides to emerge and challenge the status quo. (Humans, being what we are, will still find things to fight about so long as we are human)."

Alternatively, these colonies may invest in swords that can be readily beaten into plowshares, and then back into swords when needed. In my own setting, for example, only the largest powers (Earth, Mars, Ceres and Jupiter) can afford to maintain a dedicated military force. The smaller colonies simply have to make do with a simple refit of existing construction pods and transports for defense, converting them into crude warships by attaching guns, missiles and armor plating that was designed to be removable so that after the danger has passed, they could be easily restored to their original function (in the case of Ceres, their "permanent" military is simply this temporary measure that was never ended; only with the threat of war have they begun designing their own dedicated warships).

Thucydides said...

While this may be an interesting "phase" in your setting, the fact that several "Nation State" or Imperial powers already exist dooms the enterprise from the start.

The Italian City States were overthrown when their Condottieri and civil militias were crushed by the invading armies of Charles I. The French simply could afford to field bigger and better armies than the Italians, and as a unified State did not have to worry as much about unreliable partners changing sides or sitting out the battle.

The Classical Greek Polis suffered the same fate farther back in the past, and there is little reason to believe this won't happen in the future unless the "City State" has free access to energy and resources on the same scale as the competition.

Tony said...

Thucydides:

"The guild struck me as something analogous to the 'Knights Templar', who provided a service (escorting pilgrims to the Holy Land), and expanded into all kinds of commercial and support activities under a religious charter.

The analogy isn't exact of course, and perhaps better examples can be cited."


jollyreaper:

"Throughout most of human history we've had mysticism..."

I didn't mean mysticism in the sens of religion. I meant mysticism in the sense of mystery and security. The Guild wasn't a religion and didn't promote any that other institutions within the Empire weren't also promoting. But the Guild navigators, how they worked, and their dependence on spice was a trade secret that needed to be protected. So the Guild employed considerable misinformation and misdirection to protect it.

Jim Baerg said...

The way for City States to survive in the presence of Nation States is to confederate. The Swiss cantons are a bunch of city states that joined to become a large enough state to hold off ambitious neighbors. See also the Dutch United Provinces.

After Alexander's Empire was split by his generals, some of the Greek City States joined in Leagues, but that seems to be a case of too little too late.

vasiln said...

"Air is fairly simple... we only really need a lack of certain things...

Food requires complicated molecules like proteins (made of the 20 amino acids we're familiar with), carbohydrates, vitamins (very specific and uniquely arbitrary molecules that our biochemistry just happens to be designed with), essential fatty acids, and so on."

I don't think that's a very fair comparison. Food does not need all of those things to be nutritious-- it only needs one of those things. Past that, there's plenty of non-nutritious things that are food-like, things like Diet Coke. Just as much as atmosphere, maybe more so than atmosphere, what something needs to be food is the absence of poison. Even empty roughage serves a nutritional purpose.

Alien life may be really really alien (reproducing surfaces on clay), or it may be similar. If it's similar to the extent that it uses proteins, it's not unlikely that its proteins will be digestible (there's the mentioned issue of chirality). It's likely to have some kind of compound for energy, and sugars are nice ones, in that as far as I know, they haven't yet been supplanted on Earth. If that's a sugar that's indigestible to humans, maybe cooking (just low-tech chemistry, really) or exogenous enzymes can help, maybe not.

People have been practicing ways to separate toxins from nutrients for a long time. There are potential food sources where it's not worth the trouble, but my guess is that "Your scientists have discovered how to separate sugar from poison" is a pretty minor breakthrough compared to all of the other problems involved with living on a foreign planet.

Humans are the sorts of creatures that consume celery, blowfish, Goldschlager, and nutmeg. Frankly, I would be more surprised if we didn't find a way to run an alien species through our alimentary tract.

Anonymous said...

=Milo=



vasiln:

"Food does not need all of those things to be nutritious-- it only needs one of those things."

I think you can probably do without the carbohydrates, if you get enough proteins to burn. Everything else in my list is indispensible. Food is more than just something to burn for energy.


"Past that, there's plenty of non-nutritious things that are food-like, things like Diet Coke."

If it's non-nutritious, then you can't live entirely on that, can you? There's a time for luxury, but first you need to not starve.

Which just raises another issue - even if the local life forms are nutritious, there's no guarantee they'll taste good, and vice versa.


"If it's similar to the extent that it uses proteins, it's not unlikely that its proteins will be digestible (there's the mentioned issue of chirality)."

Earth life uses 20 specific amino acids, out of... I'm having trouble finding data but apparantly at least 90 that are chemically possible, even limiting to those with proper chirality. 9 of these the human body cannot synthesize and must obtain from food. If any 1 of these 9 is not used by the aliens' biochemistry (just like there are definitely more amino acids that Earth life doesn't use than that it does), then you simply can't survive purely on local food (although if you're lucky, you may be able to eat it with some dietary supplements).

And that's assuming your aliens use proteins at all. There could be other complex polymers that can fulfill the same role.


"People have been practicing ways to separate toxins from nutrients for a long time."

Separating toxins from nutrients is nice, but it's often harder to supplement nutrients that aren't there to begin with. Furthermore, alien toxins may be more resillient than our own. Most Earth-based biotoxins are "benign" in that they're made of familiar, Earth-life-friendly building blocks, just contorted into a harmful shape. When the building blocks themselves are toxic to us, cooking doesn't help so much.

Also, having to cook (or worse, perform advanced chemical separation procedures on) practically every meal before eating is going to cause problems. Even if people are willing to put up with that, allergies are going to go up through the roof if basic alien pollen is poisonous to us. You can't always control what enters your body.


"Humans are the sorts of creatures that consume celery, blowfish, Goldschlager, and nutmeg. Frankly, I would be more surprised if we didn't find a way to run an alien species through our alimentary tract."

Those are all things that were initially nutritious, and have tacked-on countermeasures to try to deter predation. It would be quite another thing if the poison isn't a deterrant added as an afterthought to an otherwise palatable biochemistry, but something inherent to life as the aliens know it.

Thucydides said...

I would be more surprised if we didn't find a way to run an alien species through our alimentary tract.

Step 1: run alien proteins, carbohydrates through a blender

Step 2: run the pulp through a series of catalytic converters under high temperatures and pressures

Step 3: reassemble the resulting reactants into something usable. Rinse and repeat

This is essentially the problem scientists have when trying to do relatively simple operations like converting cellulose into simple sugars for fermentation or other industrial processes. (The fact termites don't seem to have many issues doing the same thing is a bit annoying for industrial scientists...). Now add alien proteins, chirality etc. and you can see there is a huge problem.

Probably easier to have farm habs in orbit.

Rick said...

Milo - And of course, I only demonstrated the existance of a preferred frame of reference, not proposed a mechanism for an FTL drive that takes advantage of it.

Had you done the latter, you would be writing your Nobel Prize acceptance speech, not wasting time commenting on this blog.


On the Guild in Dune, I tend to agree with jollyreaper that the offered analogies don't quite fit. At least, as seen in the original book - I disliked the sequels enough that I never got past the first (and a few pages of the second).


On city-states, it seems to me that another way they could survive is to have nuclear weapons. 'God made men, but Mr. Colt made them equal.'

Other than that, carry on, while I work on coming up with a fresh post!

Thucydides said...

The endless Dune sequels got annoying (I only read Frank Herbert's sequels, and even then only half heartedly), the Refrigerator repairman of Dune is taking the concept waaaay to far...

One other advantage of Nation States over City States (or alternatives like Churches, Guilds, Feudal kingdoms etc.) is the existence of an integral "heartland". Once a missile gets through the defenses of a City State, that's the end of the story, while even a massive nuclear strike on the United States would leave large areas untouched (post-apocalyptic literature to the contrary), and the US strike, with fewer weapons over a larger area would have left even more geographical regions of the former USSR untouched.

While it would be very difficult for the survivors, there was a real possibility of being able to survive and eventually rebuild. An even stronger argument is the Nation State has many more nuclear weapons and delivery systems than a City State, so if the City State uses its weapons in a first strike, the Nation State has many more in reserve for the counter attack, while the City State cannot absorb a nuclear strike, nor can it offer much of a counter attack (even with the small number of nuclear subs they might have).

The story changes again if the City State is in orbit and can potentially call down gigatons of energy on the target rather than the typical 300KT nuclear warhead common today. At that point even a continental landmass would be devastated, and the only real issue is how good the City State's defenses are, since they will be facing a swarm of similar weapons directed at them.

Tony said...

If a city state has the resources to be in orbit, then nation states have the resources to operate in space too. I seriously doubt they would allow any power, large or small, to maneuver potential KE gigaweapons anywhere near the Earth.

Otherwise, I agree that city states have no strategic depth. They either become large nation states over time or they rely on the forebearance of nation states.

Tony said...

Rick:

"On the Guild in Dune, I tend to agree with jollyreaper that the offered analogies don't quite fit."

Truth in advertising here -- I'm not trying to present an analogy with my description of the Spacing Guild as a megacorporation. According to the Dune Encyclopedia, that's precisely what it was, in terms of overall organization and operations.

Now, the Herbert estate, in the form of Brian Herbert, wants us to believe that the Encyclopedia is not canon. But his father was a close friend of Willis McNelly, the Encyclopedia's author, and gave his explicit, written approval of the Encyclopedia. He apparently also provided considerable background material on which much of the Encyclopedia was based.

"At least, as seen in the original book - I disliked the sequels enough that I never got past the first (and a few pages of the second)."

The sequels were uneven, because they are less adventure and more contemplation, but they do provide an interesting look into the mind of Herbert.

vasiln said...

Milo, Thuc:

I think you're excluding a middle ground. Between "alien animals provide all of our nutrients" and "alien animals are totally inedible" lies a wide range of possibilities.

The original food discussion, if I'm not mistaken, came from Scholar's assertion that predators are okay because maybe you can eat them. That food source doesn't have to be complete to be a food source; it doesn't really even have to be nutritious. (Three of the things I mentioned are not really nutritious. The point of Goldschlager is not that it has calories from alcohol, but that it has inert gold flakes in it. Nutmeg might be nutritious if we ate a ton of it, but then we'd have to deal with the poisons in it, and we don't bother to worry about that, because we don't grow or eat nutmeg for its nutritive value. The same goes for celery, although celery is slightly more nutritive (vitamins) at the quantities we eat it at-- still, we don't bother separating the celery from its poison.) It's not necessary that people rely on hunting for all of their nutritional needs for that to be perceived as a benefit; there are very few people who recommend getting all of one's calories from meat even on Earth! Any source of dietary variety is going to be perceived as a benefit.

Clearly, any kind of "cooking" that involves arsenic, long hydrocarbons, cyanide is going to be more involved, maybe hopelessly involved. A lot depends on how much similarity alien life bears to us, and that's a highly debatable subject, one without much evidence available.

As for the desirability of eating alien life, the tastiness of it-- my take is that people tend to put things in their mouth because they can, and decide what's tasty later, based more on cultural factors than on chemical factors. Expensive food tastes better. We use gold flake in cooking because we can, and because it's a symbol of something, not because it tastes good. I'm not a big fan of unagi, apparently not because of some slimy disgust fixed in all human minds, but I love bacon, and bizarrely, some people find bacon nauseating.

Food allergies may be a problem, but I don't understand what would make them a bigger problem with otherwise edible/inert alien food than they are with terrestrial food. There might be something obvious I'm missing.

Anonymous said...

=Milo=



vasiln:

"It's not necessary that people rely on hunting for all of their nutritional needs for that to be perceived as a benefit; there are very few people who recommend getting all of one's calories from meat even on Earth!"

It didn't even occur to me that eating meat vs plant matter was under discussion. Alien animals and alien plants from the same planet are going to have roughly the same biochemistry (at least, more similar to each other than to us), and so if all the animals are poisonous or non-nutritious to us (as opposed to just those that evolved special defenses), then the plants probably will be too.


"Any source of dietary variety is going to be perceived as a benefit."

False. Eating bread and arsenic is less good for your health than eating just bread.


"As for the desirability of eating alien life, the tastiness of it-- my take is that people tend to put things in their mouth because they can, and decide what's tasty later, based more on cultural factors than on chemical factors."

I doubt that. Cultural values can mold your aesthetic senses to some degree, but not arbitrarily rewrite them. There are some things which are sufficiently pretty or ugly or delicious or yucky that every culture in the world will agree on this assessment.


"Food allergies may be a problem, but I don't understand what would make them a bigger problem with otherwise edible/inert alien food than they are with terrestrial food."

If you're just allergic to one particular alien life form, not a problem. If you're "allergic" to the alien biosphere as a whole, problem.

Anonymous said...

=Milo=



Addendum: You could always go the macho route, and have a culture that glorifies deliberately eating horrible-tasting food as a way to prove your toughness ;)

Thucydides said...

I don't think you are missing anything obvious, but I strongly suspect that lots of subtle interactions between alien proteins and the various receptors in your body will trigger various nasty reactions that we would rather avoid.

The same amount of time and effort needed to transform alien food molecules into something we can eat is probably far more than most people would be willing to invest, regardless of how potentially tasty the alien plants and animals might be.

Considering humans share something like 50% of their DNA with a Banana plant and we still see allergic reactions, think of how totally dissimilar plants and animals will work.

vasiln said...

"It didn't even occur to me that eating meat vs plant matter was under discussion."

It's not, really; in fact, the distinction may not even make any sense when we run into alien life. What is under discussion is whether anybody will eat alien life. For them to do that, it's not necessary for them to need to eat alien life, and it's not necessary for alien life to provide all of their nutrients, or even any of their nutrients.

"Eating bread and arsenic is less good for your health than eating just bread."

Absolutely correct. Toxins are an important factor, and perhaps one that won't ever be overcome. Nutritive value, however, is not a limiting factor.

"Cultural values can mold your aesthetic senses to some degree, but not arbitrarily rewrite them."

Coprophagia is pretty universally reviled, but some people engage in it; more importantly, infants engage in it, suggesting that our disgust isn't fixed and instinctual. Infants display aversion to bitter tastes, but specialty supermarkets still stock bitter melon, and presumably somebody is buying it. Bitter additives (to prevent kids from ingesting things they shouldn't) work very well, but not perfectly.

Humans show incredibly diverse behavior, and my feeling from a bit of time in hospitals is that if there is a hole, and something that fits in it, and a sufficiently large group of humans-- one of them is going to put that thing in that hole, no matter how bad of an idea it is (and somebody else is going to make a website about how to get that thing in that hole more safely).

Pardon me for rambling.

"You could always go the macho route, and have a culture that glorifies deliberately eating horrible-tasting food as a way to prove your toughness ;)"

Sure, although I feel the need to emphasize that that is certainly not the only way that culture affects our choice of what to ingest!

Anonymous said...

=Milo=



vasiln:

"the distinction [between plants and animals] may not even make any sense when we run into alien life."

It probably will. In any biosphere that isn't really, really alien (Europa?), your primary producers are going to be photosynthesizers. And if your biosphere has evolved much past the single-celled protists stage (which, granted, took us four billion years), then those photosynthesizers are likely to somewhat resemble plants as we know them. Note how even in our world, kelp independently reinvented the concept of leaves.

Similarly, any non-wimpy biosphere is going to have SOME kind of organisms that can move rapidly under their own power, which can be considered "animals". They probably won't look much like animals we're familiar with (though a few rough shapes are likely to recur, like that of a fish - see: ichtyosaurs, dolphins, and just the generally small amount of fish that evolved significantly away from the ancestral body plan), but I'd still count them.

I'm not sure about fungi - the "macroscopic non-mobile non-photosyntesizer" niche seems rather less important, so it's hard to say how inevitable it's going to be in other biospheres. They'll probably have some, but these could be reduced from the kingdom status they have in ours. In any case there isn't much to expect from fungi in terms of looks - the mushrooms that we're familiar with are actually fruiting bodies rather than the main organism, and their shape is rather arbitrary.

One way to mix things up would be to have animate plants (that science fiction authors are so fond of), but one questions how much good this will do them. Animals generally need mobility to find food - even if they're herbivores so their prey doesn't try to run away (well, unless your herbs can run), they generally need to eat more than can be found in one spot, so they need to roam and graze/browse/whatever. There are other advantages to mobility - escaping predators, finding mates without relying on wind or symbiotic pollinators, seasonal migrations - but I suspect that those are secondary functions to finding food, worth improving on once you're already mobile, but not valuable enough to evolve mobility for those purposes alone on most planets. There are easier ways for plants to deter predators.


"it's not necessary for them to need to eat alien life, and it's not necessary for alien life to provide all of their nutrients, or even any of their nutrients."

That's right, people could potentially eat alien life just for the taste, if it isn't poisonous (and we're lucky enough to find an alien life form that tastes good). However, if we do so we would still need some other source of food, so the presence of an alien biosphere wouldn't actually make our settling the planet easier in the way the presence of an alien oxygenated atmosphere would.

Rick said...

Sheerest speculation, but we might find in which organisms commonly shift mode according to circumstances. Yes, there are good arguments why this is doubtful, but with only one example to go by, it is hard to be very authoritative!

Anonymous said...

=Milo=



Hmm. Plant-animals as generalists. There certainly is a place for both generalists and specialists in an ecosystem. Is this going a little too far? Maybe, maybe not. But we already have carnivorous plants, even if they're rather wussy compared to metazoan carnivores...

Also I completely forgot that Earth already has photosynthetic animals. I even mentioned them before on this blog. They are, however, by no means a dominant life form.

Thucydides said...

Deep in the past we *may* have seen some types of life that are dissimilar to what we have today; the Ediacaran biota do not seem to resemble anything that exists in the present day, and many of the creatures of the Burgess Shales early in the "Cambrian Explosion" have no obvious links to present day living creatures or even phyla.

Since the actual fossil evidence is very scant, there is little to confirm or deny the relationships between these creatures(?) and modern living organisms. The only thing we do know for certain is the early Earth was an alien place 500 million years ago, with a different atmosphere, rotation rate and even the amount of sunlight.

Anonymous said...

I dunno, not many folks seem to have wanderlust for the wilderness anymore. Just for road trips.

Most of the sociological studies i have seen on young men now focus on how much time they spend gaming, and when they do go out, it is to a mall, a movie, a bar, or a restaurant.

Our last few generations have been socialized with the Wild West. Next Gen has been socialized with text chat. Don't think they much care where they do that.

Lots of studies talking to women who complain that none of the men want to leave the house, unless it is sports or food.
Seems likely that our dependence on an open sky is decreasing weekly.

Give em a sex bot, and a comm line, and the guys of the future may be happy meeting up at a asteroid gas station/sports bar a couple times a year.

And yes, i do see this every day, i run a hiking shop !

Tony said...

Anon:

"I dunno, not many folks seem to have wanderlust for the wilderness anymore. Just for road trips.

...

And yes, i do see this every day, i run a hiking shop !"


I have to wonder where this hiking shop is. Youth participation in outdoor sports is quite high here in semi-rural Southern Utah. I think what might be factual is that fewer and fewer people live in places where the outdoors is easily accessible at a reasonable price, therefore they anesthetize themselves with substitutes. I know for a fact that a lot of the city kids I knew in the Marine Corps, once they became confortable with the field environment, could be just as effective as country boys.

I don't think the actual human desire for the outdoors is diminishing, just the opportunity to enjoy it.

Anonymous said...

=Milo=



Tony:

"once they became confortable with the field environment"

Implying that it required training rather than coming naturally to them. Have you tried locking some farmboys in a mansion with lots of computers and gaming consoles but no way out and seeing how long it takes them to "become comfortable" with playing video games?

Anonymous said...

I have to agree with Tony on this; take away the oppertunity for something and we tend to substitute something else. Humans are adaptable to an astounding degree, and this may just be another example. Relating to space colonies, once we get past the initial generation, the colonists should be ok with their enviornment.

Ferrell

Tony said...

Milo:

"Implying that it required training rather than coming naturally to them."

Non sequitur fallacy -- rural kids need just as much instruction in their environment as a city kid would. They just get it early and often. Also, because they have more opportunity in the wilderness environments at the margins of their communities, they have a lot more practice. That doesn't mean they are genetically more adpated or require less teaching.

"Have you tried locking some farmboys in a mansion with lots of computers and gaming consoles but no way out and seeing how long it takes them to 'become comfortable' with playing video games?"

Probably not long. But that doesn't mean they would lose their wilderness knowledge. Their practical skills might degrade over time.

Ferrell:

"Relating to space colonies, once we get past the initial generation, the colonists should be ok with their enviornment."

This is purely anecdotal, but I think it is illustrative. I grew up in and was happy living in a city. Or at least I thought I was happy. I didn't know just how unhappy I was until circumstances conspired to move me to a more rural area. Humans may adapt to cities, but I simply don't believe that's where they'd prefer to live, given the choice. Certianly the biggest influx of new residents into our community over the last couple of decades has been upper middle class retirees from Eastern and Middlewestern cities.

Rick said...

Welcome (possibly!) to a new commenter!

I do encourage 'anonymous' commenters to sign a name or handle (like Milo and Ferrell) so we can keep identities distinct.

Living long-term in a can, even a big one, might have negative effects that we have not experienced - even prisoners are exposed to the outside atmosphere.

Or perhaps not - we won't know until we put it to the test. My intuition is that internal variety is more relevant than sheer size, but intuition plus $3.50 will get a cup of coffee at Peet's.

Anonymous said...

"Alternatively, these colonies may invest in swords that can be readily beaten into plowshares, and then back into swords when needed. In my own setting, for example, only the largest powers (Earth, Mars, Ceres and Jupiter) can afford to maintain a dedicated military force. The smaller colonies simply have to make do with a simple refit of existing construction pods and transports for defense, converting them into crude warships by attaching guns, missiles and armor plating that was designed to be removable so that after the danger has passed, they could be easily restored to their original function (in the case of Ceres, their "permanent" military is simply this temporary measure that was never ended; only with the threat of war have they begun designing their own dedicated warships)."

Are you familiar with the de Havilland Mosquito (http://en.wikipedia.org/wiki/De_Havilland_Mosquito)? Something similar, but possibly more adaptable (and not made of wood!) may be what you're thinking of. A craft capable of serving as a space fighter in orbit (the only place they make sense) or a bomber, depending on what is required (though you still run into the economics, which tell you it's a crazy idea when you can just use a robotic craft to do the same thing...). Perhaps, they could be small surface-to-orbit and interorbital shuttles, with a cargo bay that can be swtiched out for various roles (cargo, passengers, bombs, laser/mass driver...).

One could possibly apply similar thinking to larger craft - a freighter that could be modified to become a carrier or battleship. It depends on what kind of design you're using, and how much shielding it allows for. If you're using a nuclear engine, you might be able to go bimodal and have all the power you need coming from your engines (making it a true tradeoff between fight or flight). Thinking of it, you could probably use your deceleration burn to clear the area, if your engines are powerful enough...

The local police will, of course, have patrol boats, perhaps with magnetic grappling hooks to allow craft to be boarded...

- Terraformer

Tony said...

Re: Mosquito

The Mosquito leveraged a large, preexisting cabinetmaking industry, enabling an alternate structural composition. Also, it still required all of the engines, radios, isntrumentation, etc. of any aircraft. It could only have been made in a wealthy country. It's not really a good analogue for some kind of poor planet expedient spacecraft.

On the general subject of relatively poor planets vs relatively wealthy ones, well...if the wealthier planet has the logistics to mount an attack in the first place, there's no reason to expect that it won't win, all other things being equal. There really is no alternative to absolute strength.

Thucydides said...

Just revoke the "zeoith law of space combat" and make every available ship a bus for warheads. Nuclear warheads if you have the resources and industry to do so, but even KE penetrators will do nicely, considering the amount of delta V needed to get places gives them a huge amount of energy. Even a large, high tech polity will have to devote a large portion of its resources to deal with this sort of attack, and everyone will have to think carefully about the cost/benefit ratio of space war (even very limited engagements would have the potential of escalating out of control once one side concludes they cannot win but are unwilling to lose the battle/war).

Going back to the initial topic, it seems that most stars are now considered to have some sort of planet or planetary system orbiting it. While this brings us closer to the golden age/Star Treck model of planetfall in every system, we also need to consider the evidence that most known stellar systems are very unlike our own. Planetfall near a "Roaster" gas giant orbiting the primary at a fraction of an AU will be pretty unpleasant.

Anonymous said...

Thucydides:

"Going back to the initial topic, it seems that most stars are now considered to have some sort of planet or planetary system orbiting it."

But how many of those are habitable? To either humans or aliens?

Anonymous said...

My point about the Mosquito was not that it used abundant materials, but more about it's adaptability - it saw service as a fighter, bomber, survelleince...

A small colony may not be fighting the home planet, but other colonies, in which case their lower technology level will not be a disadvantage. I'm thinking about war in Saturn orbit between moons, rather than war between Mars and Terra.

- Terraformer

jollyreaper said...

My point about the Mosquito was not that it used abundant materials, but more about it's adaptability - it saw service as a fighter, bomber, survelleince...

A small colony may not be fighting the home planet, but other colonies, in which case their lower technology level will not be a disadvantage. I'm thinking about war in Saturn orbit between moons, rather than war between Mars and Terra.


The real question is how much performance you'd need from the vessel.

The US military canned a recent program for box-launched missiles.

http://www.globalsecurity.org/military/systems/munitions/net-fires.htm

In May 2010 the Army canceled the Non-Line of Sight-Launch System, a billion-dollar missile program under development by Tucson, Arizona-based Raytheon Missile Systems and Lockheed Martin. The Navy was still evaluating its options for the system, which it had been considering for use aboard the Littoral Combat Ship. The modular system, known as NLOS-LS or simply NLOS, features 15 all-weather missiles in a common launcher that can be mounted on an array of military vehicles. The NLOS-LS was part of the Army's Future Combat Systems program, which was canceled last year.

These missiles could be sat on the flatbed of a truck, the deck of a ship, out in a field, etc.

Now if we extrapolate that tech just a wee bit into our future and look at the converted auxiliary combatants from WWII where tugs were fitted as ASW craft, trawlers became minesweepers, and imagine a similar situation in the near future but where you can convert any old ship into a missile launcher, where a pickup truck could now become a poor man's MLRS.

A purpose-built military vessel might have better performance and and be more survivable but I wouldn't discount the danger posed by auxiliary forces.

Tony said...

Re: KE attacks by non-warships

It all of course depends on the precise means of interstellar travel, but even with the freest of free-from FTL, one still has to equip one's weapons with adequate guidance sensors, processors, and effectors. Otherwise the targets will just dodge the attacks like the ISS regularly dodges space junk. See, the converted merchant ship is yet another example of people thinking about tactics and ignoring logistics.

The problem is that one needs a large and intricate industrial base to make sufficient weapon guidance suites. Let's take for example jollyreaper's suggestion that with sufficiently self-contained weapons systems, any truck can be turned into an MLRS. That's true, as far as it goes. But where does one get the weapon systems? From wealthy economies that can actually make them. If you're at war with a wealthy state, one better have an equally wealthy ally to supply you. And even if you have a wealthy supplier, it turns out that merely buying sophisticated systems andtheir ammunition doesn't make one sophisticated one's self. So your wealthy enemy not only has high-tech weapons, but a high-tech manpower pool to use them and sophisticated doctrines and logistics systems to make them work well over the long run.

jollyreaper said...

The problem is that one needs a large and intricate industrial base to make sufficient weapon guidance suites. Let's take for example jollyreaper's suggestion that with sufficiently self-contained weapons systems, any truck can be turned into an MLRS. That's true, as far as it goes. But where does one get the weapon systems? From wealthy economies

That brings a lot of different questions into the equation, true. Depending on the era in question, there wasn't a whole lot of difference between general-purpose ships and warships. You would see civilian ships fitted with extra guns and suddenly it's not that bad of a warship. By the age of the ironclad half-assed civilian conversion jobs were never exactly satisfactory.

As for the socio/politico/economic implications, that's what makes for an interesting story. To use the example of the American revolution, Britain had more power and on paper the British forces should crush the Americans. But they're fighting at the end of a long supply train, have complications elsewhere in the world to worry about and the Americans ended up getting help from one of Britain's chief allies.

To look at another perspective, the North Vietnamese did not have the domestic capability to fight the Americans and were supplied by a major industrial power. But in terms of telling one hell of an interesting story, there you go. The North Vietnamese air force is going up against a world superpower but one that is fighting with severe constraints. It's an incredibly target-rich environment and the defending pilots are fighting over friendly territory most of the time. There were several VPAF aces. Must be some damn good stories from that war.

Tony said...

jollyreaper:

"That brings a lot of different questions into the equation, true. Depending on the era in question, there wasn't a whole lot of difference between general-purpose ships and warships. You would see civilian ships fitted with extra guns and suddenly it's not that bad of a warship. By the age of the ironclad half-assed civilian conversion jobs were never exactly satisfactory."

The period where purpose-built warships and repurposed merchant ships were roughly equivalent in combat power was pretty short. Maybe between 1550 and 1625. In fact, during that period, it was much more accurate to say that merchant ships were all effective warships, because they had to be. From the middle of the 17th Century and later, warships easily outperformed merchant ships taken up into service simply because they grew into ships of the line and became more optimized for their roles, to the point that non-optimized ships couldn't compete.

A well-armed merchantman may indeed have been able to take on a light frigate of 22-26 guns, but that only served for convoy escort. Even if a minor power's navy had a compliment of frigates, without sifficient ships of the line it couldn't assert its dominance on the high seas. It's ships had to run rather than fight, whenever a greater power's ships of the line appeared.

"As for the socio/politico/economic implications, that's what makes for an interesting story. To use the example of the American revolution..."

The American Revolution illustrates the importance of logistics over tactics. The British, as at Long Island, could win battles that they could bring a large enough army to. The problem was that they could never bring enough troops to North America to achieve anything more than a stalemate. And when the French got involved, that was the end of that.

"To look at another perspective, the North Vietnamese did not have the domestic capability to fight the Americans and were supplied by a major industrial power..."

And they only lasted because that major industrial power extended a nuclear shield over them. There are a few interesting tactical stories that resulted from that. But the overall strategic story was about superpower confrontation through proxies, not about a plucky little guy tweaking the nose of a big bully.

I have no problem with stories like that. But they had better be set within a proper context that recognizes where the real power comes from.

Thucydides said...

Actually, there were many periods when merchant and warships were essentially repurposed platforms, but this was an artifact of most naval combat prior to the mid 1400's being considered and carried out as a form of Infantry combat. (Bronze age ships could be merchantmen or privateers as the ships master desired, but purpose built warships did exist during the post bronze age ancient world as well).

Fill the hold with soldiers (Marines as a separate class of fighting troops don't seem to have existed prior to the age of fighting sail) and erect some fighting castles on the bow and stern and you have a decent fighting vessel in the middle ages. I'm sure this is what was being referred to when suggesting that space craft can be repurposed as warcraft, although I'm pretty sure there are no analogues to chaining a fleet together to create a stable fighting platform as was done in the Battle of Sluys in 1340.

Using busses to transport large numbers of submunitions is a way of leveraging whatever resources you do have; a limited number of seekers will allow you to carry a large number of submunitions and carry out "shotgun" attacks in an attempt to overwhelm defenses and negate the ability of enemy craft to move (or spread damage over a wide area of large targets). All the bus needs to do is get the warheads into position where the cone of destruction intersects the target. Even dumping the warheads early if the bus is attacked may cause enough confusion to help the next wave through. I can see this as a response to being threatened by a bigger polity with greater military an economic resources.

Tony said...

Thucydides:

"Using busses to transport large numbers of submunitions is a way of leveraging whatever resources you do have; a limited number of seekers will allow you to carry a large number of submunitions and carry out "shotgun" attacks in an attempt to overwhelm defenses and negate the ability of enemy craft to move (or spread damage over a wide area of large targets). All the bus needs to do is get the warheads into position where the cone of destruction intersects the target. Even dumping the warheads early if the bus is attacked may cause enough confusion to help the next wave through. I can see this as a response to being threatened by a bigger polity with greater military an economic resources."

A bigger polity with greater military and economic resources has many more bus type attack systems, not to mention numerous defensive systems to keep someone from launching anywhere near high value targets. In fact, it would probably bring the war to your fleet long before you could bring the war to his. Maybe you mount one or two successful raids against peripheral systems. Maybe you even mount one successful surprise raid against a core system. Then the superior power comes and nukes you to smithereens.

You can't win a fight by holding a gun to the head of one soldier, while the rest of the squad is aimed in on you, waiting for you to pull the trigger.

Christopher Phoenix said...

Milo:

"I just found a preferred frame of reference, so it must be pretty easy. (To be fair, anything is easy once other people did the hard work.) So, I have to conclude that Mark Millis is distressed because he is misinformed. Some people avoid the most obvious pseudoscience traps, only to fall into the less obvious traps hidden immediately behind them."

I'm afraid you've fallen in your own pseudoscience trap- and you are definitely NOT smarter than Mark Millis. Comoving Coordinates are not a "special frame of reference", they are just a more natural set of coordinates to use. Nor do they help us avoid causality violations during FTL travel.

To create a time-travel paradox, you need to have two different FTL trips in two different reference frames. If there are certain provisions in place, then FTL travel cannot result in time travel paradoxes- but we don't know if any of these provisions are actually the case.

If all ships entering FTL travel have to enter the same special reference frame (the "FTL ether"), then time travel paradoxes are impossible. This is one way to avoid paradoxes, but it does seem to violate the principle in relativity that there are no special frames of reference (if you are going to argue about this, go find a good book on relativity read it!!).

Of course, FTL schemes have to find a way to "get around" relativity in the first place, so this special frame could have nothing to do with ordinary relativistic physics. The author can explain that the space-fold drive manipulates some some special field that just happens to have a particular frame of reference, forcing the FTL starship to take on the frame of reference of the special field, or so on.

Mark Millis is distressed because there is nothing in physics that stops Sally the would-be chrononaut from accelerating one mouth of a wormhole to relativistic velocities, flying around, then bringing it back to the other mouth. If the popularizers of science explained this correctly, this will create a time machine.

Sally can then fly her rocket ship through the wormhole time machine and arrive back at the launching site of her rocket before she took off. She could stop herself by leaving in the first place- perhaps by launching a nuclear-tipped rocket at the launch site. Viola!! Time travel paradox!! How can Sally be there to stop herself from making the trip if she prevented her earlier self from starting the trip?

Comoving Coordinates don't do anything to prevent Sally from creating a wormhole time machine. There is some speculation that quantum effects would destroy the wormhole before Sally could bring the two mouths close enough to facilitate time travel- but this is just speculation. If someone creates the large amounts of negative energy we need to stabilize wormholes, scientists are going to have to grapple with the possibility of creating a real-life time machine.

BTW- quantum mechanics doesn't "prove" that Relativity is incomplete. Quantum mechanics applies to the very small, where everything comes in discrete packets called quanta. Relativity describes the very large and very fast- planets, galaxies, starships, etc. Physicists are having difficulty in fitting the two together, but both theories work rather well in their own arenas. Quantum particles behave in strange and surprising ways- but doesn't mean that there is a "preferred frame of reference" in violation of Relativity, and even if there was, Comoving Coordinates isn't it.

Thucydides said...

Leveraging your limited resources does not mean you will win the war, but simply that you can stay in contention, or at least make sure your enemies treat you with a certain amount of caution and respect.

This might also work if the opposing polity has political or economic difficulties at home, or is reluctant to fight for any reason. The British Empire had more than enough resources to smash Nazi Germany, and even the combination of all the Axis powers could not have realistically overwhelmed the Empire in the end (a WWII in that timeline would continue until the late 1940's), but the memory of WWI, British politics and the effects of the Great Depression kept Britain from acting until the last possible second. Similarly, the idea that we should be paralyzed by Islamic terrorism or rogue states attempting to develop nuclear technology seems highly improbable given the vast mismatch in capabilities; even minor Western allies like Canada and Australia can project military and economic power across the globe, wheras there is no way a battlegroup of soldiers from the DPRK or Iran will ever show up in Canada or Australia. But since they do have the implicit threat of nuclear or terroristic actions on our soil, we are indeed constrained in our actions.

Anonymous said...

=Milo=



Christopher Phoenix:

"Comoving Coordinates are not a "special frame of reference", they are just a more natural set of coordinates to use."

Umm, a special frame of reference is a natural set of coordinates to use.

Comoving coordinates are special/natural in that they are a single, unique frame chosen based on non-arbitrary factors where no other choice could be made that would have preserved the spirit of the system.

If I declare a frame of reference aligned with Earth then that is arbitrary, because I could have just as easily declared a frame aligned with Gliese 581d and neither planet is inherently more important than the other as far as the universe is concerned. If I declare a frame aligned with the cosmic microwave background radiation then it is non-arbitrary, because there is only one cosmic microwave background radiation, and nothing else is quite like it in the universe. This makes it, per definition, a special frame of reference, whether or not it happens to be usable as an FTL ether.


"Mark Millis is distressed because there is nothing in physics that stops Sally the would-be chrononaut from accelerating one mouth of a wormhole to relativistic velocities, flying around, then bringing it back to the other mouth."

Wrong. There is something in physics that stops Sally from doing that, because physics as we know it doesn't allow the creation of wormholes. It has some vague ideas of how wormholes might work if they worked, but we still have no real idea how to make one, and there's good reason to think that it isn't possible. Physicists being able to describe wormholes as a relativistic spacetime topology doesn't imply wormholes are possible, any more than mathematicians being able to describe i as a number that arithmetic can be performed on does not imply that a shepherd can count i sheep in his possession.

If you have wormholes in your setting then you're already introducing new laws of physics, so why not also introduce a special frame (or an excuse for how the special frame we already have can be used as an FTL ether)?


"Sally can then fly her rocket ship through the wormhole time machine and arrive back at the launching site of her rocket before she took off. She could stop herself by leaving in the first place- perhaps by launching a nuclear-tipped rocket at the launch site."

Look, I know what time paradoxes can arise from careless forms of FTL, okay? I'm just saying that avoiding them in a physically consistent manner is not that hard, for storytelling purposes. (In fact, wormholes are one of the harder forms of FTL to avoid time paradoxes with, if only because there's no obvious reason why wormholes would be tied to an FTL ether even if one existed.)


"Comoving Coordinates don't do anything to prevent Sally from creating a wormhole time machine."

Not if you can create wormholes and move them around freely ignoring the comoving frame, no, duh. However if, due to some here-to-fore undiscovered physical principle, both ends of a wormhole are constrained to always be in the same comoving time coordinate, then I am pretty sure this will eliminate time paradoxes. (I'm not 100% clear on the math, so if you show me math disproving this, I will back down.)

Anonymous said...

=Milo=



Christopher Phoenix:

"There is some speculation that quantum effects would destroy the wormhole before Sally could bring the two mouths close enough to facilitate time travel- but this is just speculation."

As is everything else about wormholes. Your point?


"If someone creates the large amounts of negative energy we need to stabilize wormholes,"

Thanks for proving my point that you're talking about things that don't exist in science as presently known. Negative energy, huh? And you call special frames of reference unrealistic.


"BTW- quantum mechanics doesn't "prove" that Relativity is incomplete."

Yes, it does. It doesn't prove that relativity is incomplete in the particular manner that would be convenient for me and us (by allowing FTL), but it does prove that relativity is incomplete in at least SOME manner.


"Relativity describes the very large and very fast- planets, galaxies, starships, etc. Physicists are having difficulty in fitting the two together, but both theories work rather well in their own arenas."

Yes. But relativity, while describing things on a large scale, is still local, telling you how to understand things from the viewpoint of a planet, galaxy, etc. It doesn't describe cosmology - all of space and time viewed as the big picture, from the Big Bang onward.

FTL is inherently less local than STL, and occasionally requires viewing things on a larger scale than relativity.

Rick said...

On auxiliary warships and scratch weapons, the big kids pretty generally beat up on the little kids. (Though nuclear weapons can restrain how much.)

Fights between little kids could be a different matter, particularly if the big kids are far away and not inclined to get involved. But making this type of scenario truly robust could be challenging.

Mangaka2170 said...

Regarding the FTL paradox debate: It strikes me that a better way to resolve this is by taking two distinct frames of reference into account; the origin point and the destination.

If I wanted to travel between Earth and Gliese 581d faster than light, my arrival in the Gliese system would not be observable from Sol, assuming that we don't have FTL sensors as well. So, why should it matter where my destination point relative to Earth is?

Or, to clarify, my destination point would most likely be calculated relative to Gliese 581d, thus making my origin point irrelevant once I arrived. As a result, while I am only engaging in one frame of reference at a time, two must be considered for the jump to be complete.

Granted, this probably only makes sense for jump drives (like in BSG), but it's still something to consider.

Tony said...

Thucydides:

"Leveraging your limited resources does not mean you will win the war, but simply that you can stay in contention, or at least make sure your enemies treat you with a certain amount of caution and respect."

Only if you can project your limited resources onto objectives that have value to your economically and militarily superior opponent. Otherwise your just a minor state waiting to be gobbled up. We live in a special time where anybody with a certain technological sophistication can attack anybody else with a significant amount of power, thanks to ballistic missiles and nukes. In an interstellar age, that won't likely be the case any more. Things will be much more like the 19th Century, with interstellar travel being analogous to ocean travel and interplanetary travel being analogous to interstate travel on the land.

"This might also work if the opposing polity has political or economic difficulties..."

So they can't gobble you up right now. Come again in a couple of years and see what the situtation is like.

Tony said...

Re: Cosmic Microwave Background (CMB) as a frame of reference

The CMB is not a universal frame of reference. It's perfectly local at any given time, since it is nothing more than photons that have been travelling since the universe became transparent (~= T(sub)0 + 300,000 years). When those photons impact on a detector or interact with anything that can absorb or deflect them, it's a local event.

Re: relativity and quantum mechanics, completeness and special frames

The completeness of both relativity and QM depends on what you mean by "complete". Both are complete within their own scale spaces. But relativity doesn't work at QR scales, while QR doesn't work at relativistic scales. So it's not so much a question of completeness as it is a question of not being effective at all scales. What that means, and how that is resolved, are the big questions in physics right now. Could a special field provide the link by which the transformation is made? Possibly. But there's no fundamental reason why it has to be a universally invariant field of "special" effect. Both gravitation and inertia certainly seems to be universally invariant, but they both fit into relativity and QR.

IOW, who knows?

Anonymous said...

When it's a fight between two moons of a planet (such as Jupiter or Saturn), each with a population in the low hundred thousands, auxiliary craft may well be sufficient. If the larger power has to stretch it's supply line thin enough, auxiliary craft may be sufficient. If the warfare is between, say, Terran forces attempting to impose their will on Callisto, the defender has the advantage even with lower technology, because not only will they have the entire system mapped out, but they will be able to replace vehicles faster, and they'll be supplied from a place that will be maybe a few thousand km away, compared to Terran forces which have to travel a billion km. However, I wasn't actually suggesting auxiliary craft; rather, I proposed that craft should be interchangeable between roles. Sometimes you'll need 100 fighters, sometimes 50 bombers, and if you've only got the resources to build 100 craft, build 100 fighter-bombers.

Since I don't generally operate on an assumption of FTL, going more for rogue planets and brown dwarfs ala Permanence, I probably attack the problem from a different perspective - my universe is one where interstellar travel is controlled by an Imperial corporation, and is heavily regulated, because RAIR craft capable of 0.6c are very dangerous things. The Terran Empire is maybe 4 lightyears across, so there's a maximum of 2 years for a communication from Terra to reach the outer colonies. I'm going more for economic (yes, interstellar travel is rather cheap, about comparable with orbital launch today - hence why it is so heavily regulated) and cultural ties which hold the Empire together, rather than brute force - a colony could secede, but they'd be ignored by everyone around them, and would lose out on important information (such as new drugs) and new immigrants. With a travel time of maybe 9 months to a year between systems, the nature of the game is fundamentally changed.

- Terraformer

Tony said...

In a Solar System context, I simply don't see multiple planetary axes of power for the next millenia (and possibly longer). The vast majority of people will live on Earth, and Earth states or megacorporations will finance -- and gain the benefits of -- space exploration/settlement. That means that the military focus will always be on the Earth and Earth orbitals. Win there, and winning everywhere else will be automatic. There may be military forces distributed throughout the system, but they will be deployed to specific points where interests need protection, and will only be effective locally, and only forl the purpose of policing and deterrence of irresponsible adventurism.

Anonymous said...

=Milo=



Mangaka2170:

"Regarding the FTL paradox debate: It strikes me that a better way to resolve this is by taking two distinct frames of reference into account; the origin point and the destination.

[...]

As a result, while I am only engaging in one frame of reference at a time, two must be considered for the jump to be complete."


This is exactly the problem. The time paradoxes result from the hypothetical ability to engage in FTL in two different reference frames - in which case you could travel in one direction using one reference frame, travel back using a different reference frame, and arrive before you left.


"If I wanted to travel between Earth and Gliese 581d faster than light, my arrival in the Gliese system would not be observable from Sol, assuming that we don't have FTL sensors as well."

Even if you don't have explicit FTL sensors, you could always fly back and show people your travel souvenirs. FTL travel implies FTL communication, even if it's just by courier. So yes, they can observe your arrival.

Damien Sullivan said...

Big power vs. little power: logistic trains may end up mattering. And local advantages, like the ability of the Dutch to flood their lands, standing not-wetland militaries even those from the largest empire in Europe. For space, the great power is great, but has to send ships -- and bring them back; the 'little' power can still have vast resources of shielding and heat sink compared to any feasible fleet. Sort of like how dug-in Switzerland is.

Christopher Phoenix said...

Milo:

"Umm, a special frame of reference is a natural set of coordinates to use."

Maybe I'm not making it clear to you what a special frame of reference is. A "special frame" or "preferred frame" of reference is similar to the concept of absolute rest- the laws of physics would be "simpler" in one special reference frame where all measurements are official. The first major postulate of Special Relativity is that no such reference frame exists- there is no such thing as absolute rest. Read below:

"While general relativity allows one to formulate the laws of physics using arbitrary coordinates, some coordinate choices are more natural (e.g. they are easier to work with). Comoving coordinates are an example of such a natural coordinate choice. They assign constant spatial coordinate values to observers who perceive the universe as isotropic. Such observers are called "comoving" observers because they move along with the Hubble flow."- Wikipedia

The article states that General Relativity allows one to formulate the laws of physics using any set of coordinates you want too- you just picked a set of coordinates that are easier to work with and are now claiming that they constitute an absolute reference frame.

News Flash, Milo: The concept of absolute rest was put to rest in 1887 when the Michelson-Morlay experiment failed to detect Earth's motion through the aether.

Christopher Phoenix said...

Milo:

"Wrong. There is something in physics that stops Sally from doing that, because physics as we know it doesn't allow the creation of wormholes. It has some vague ideas of how wormholes might work if they worked, but we still have no real idea how to make one, and there's good reason to think that it isn't possible."

This explains Mark Millis's concern. The various schemes physicists cook up for FTL travel also allow for the creation of time travel paradoxes. This is a rather large issue- that and the fact that transversable wormholes require exotic matter that we aren't sure we can create in the quantities required. The fact that FTL travel=time travel makes this a whole lot more complicated.

BTW- modern physics isn't complete enough yet to settle the question of whether we can create wormholes or not. We need a quantum theory of gravity for that.

"If you have wormholes in your setting then you're already introducing new laws of physics, so why not also introduce a special frame (or an excuse for how the special frame we already have can be used as an FTL ether)?"

Guess what- you can't just apply fictional limitations to actual research. Sure, a SF author can apply these limitations to the fictional starships in his SF setting- but Mark Millis can't make up new laws of physics as he goes along.

You are not so smart that you just avoided a pseudoscience trap that all the physicists who ever studied FTL travel fell into. Discussing the constraints authors and artists apply to fictional universes is just changing the topic.

"Thanks for proving my point that you're talking about things that don't exist in science as presently known. Negative energy, huh? And you call special frames of reference unrealistic."

Ever heard of the Casimir Effect?

"Yes. But relativity, while describing things on a large scale, is still local, telling you how to understand things from the viewpoint of a planet, galaxy, etc. It doesn't describe cosmology - all of space and time viewed as the big picture, from the Big Bang onward."

Discuss that with the cosmologists. According to them, General Relativity allows us to explore the conditions at the beginning the universe. How do you suppose physicists formulated the mathematics that describes the Big Bang without General Relativity?

Anonymous said...

=Milo=



Christopher Phoenix:

"A "special frame" or "preferred frame" of reference is similar to the concept of absolute rest- the laws of physics would be "simpler" in one special reference frame where all measurements are official."

Which laws?

The laws of relativity are not simpler in any frame. But there are other laws. And even hypothetical laws not discovered yet (like those describing FTL). As long as any of those laws are simpler in a frame, it's a special frame.


"The article states that General Relativity allows one to formulate the laws of physics using any set of coordinates you want too- you just picked a set of coordinates that are easier to work with and are now claiming that they constitute an absolute reference frame."

Umm, isn't that what you just said? You said a special frame is one where the laws of physics are "simpler", not the only frame in which the laws of physics can be formulated at all. If it's "easier to work with", then yes, it is, indeed, simpler.


"Discussing the constraints authors and artists apply to fictional universes is just changing the topic."

Okay then. If you're able to discover new laws of physics that allow FTL, then who's to say you won't also discover new laws of physics that allow you to avoid causality paradoxes while you're at it?

I find that a lot easier to believe than time travel being possible.

If you want the absolute, no-nonsense, completely-realistic answer, then it's "We don't know yet whether there is any preferred frame that FTL could work off. Maybe with more research, we'll find out.". Neither a yes nor a no answer is precluded by current science.

Thucydides said...

"Simpler" and "Easier to work with" are not equivalent concepts in this case.

Simpler would imply an entire set of principles, laws or theories which reduce everything to some basic set of rules (sort of like what people woho study string theory, "M" theory, Supersymmetry etc. are hoping for)

Easier to work with in this case would be equivalent to converting your accounting system from Roman Numerals to Arabic numerals so your calculations are not so involved.

Tony said...

Even if a theoretical means of FTL transport could be determined, there's no guarantee that it would be any more accessible, in terms of the energy required, than relativistic flight between the stars.

Rick said...

there's no guarantee that it would be any more accessible, in terms of the energy required, than relativistic flight between the stars.

True! But if you're gonna bend known physics to have FTL, you may as well have a convenient one!

This whole subthread underlines my argument for avoiding 'wormholes' and similar jargon. If it turns out that there really is an FTL (and a useful one, to boot!) it is unlikely to derive so directly from present-day conceptual speculations.

Christopher Phoenix said...

Milo:

"Which laws?"

The basic principle of relativity is that observers in any reference frame deduce the same laws of nature. This is the basic idea from which all the weird and counter-intuitive consequences of relativity come from.

To understand this, we need to go back almost a century, when Albert Einstein was merely a Swiss patent clerk. He was trying to resolve a major conflict between Newton's Laws of Motion and Maxwell's equations that describe electromagnetism. Newton's laws described all motion anywhere in the universe, and Maxwell's equations led to the electrical devices that were revolutionizing the world at the time- and revealed the nature of light.

There was a problem, however. The speed of light, C, is built into Maxwell's equations and depends only on constants that were measured experimentally. For Maxwell's equations to hold true, everyone must see the same speed of light.

But, in the Newtonian view of the universe, we should be able to catch up with light or measure different speeds of light when a light source is moving toward or away from us. Consider this thought experiment:

The evil mind-controlling alien slugs from Titan are attacking the Earth, and Commander Chekov has to intercept the slug's flying saucer in his rocket ship and destroy it. Chekov's rocket is moving at 30km/s relative to a stationary observer on the Moon. He fires a megabomb from his mass-driver cannon at 5km/s straight at the invading saucer. The observer back at the moon base sees the projectile traveling at 35km/s, since the velocities add like this:

30km/s+5km/s=310km/s

This is common sense in the Newtonian view. Velocities add.

The evil aliens dodge the megabomb, so Chekov fires his high-power laser cannon. A deadly beam of light shoots through space, scoring a hit on the saucer's hull. The slugs' saucer explodes into a cloud of debris.

But what of the observer on the Moon? How fast does the laser seem to travel according to her?

Light travels about 300,000km/s. So, we would expect that the observer on the moon would see the laser beam travel at 300,030km/s- right? But this is a clear paradox- for light to travel faster than C would be a violation of Maxwell's equations. How can we resolve this paradox?

Continued...

Christopher Phoenix said...

Einstein thought about this problem, and he reached the conclusion that there were only three ways to solve the problem.

1. The laws of physics might be different in different reference frames. In other words, different versions of Maxwell's equation would be needed in different situations. Everywhere we look, the same laws of physics operate- so this idea doesn't seem to apply to the universe we live in.

2. Maxwell's equations could be just plain wrong. Physicists were unwilling to believe this, since experimental evidence strongly supported Maxwell.

3. Or, finally, the commonsense notions we have about how velocities add could be faulty. If this is true, the universe is a much stranger place than we thought.

Einstein chose to focus on the third possibility, and the rest, as they say, is history. From the simple idea that observers in all references frames see the same natural laws comes (all through simple arguments and high school algebra, mind you) time dilation, length contraction, relativistic mass increase, and the rest.

How does this help resolve our paradox? Our observer on the Moon sees Chekov's rocket as being slightly contracted its direction of motion. Glancing at her watch, she sees that Chekov's chronometer is ticking slightly more slowly than her watch. These effects make the addition of velocities somewhat more complicated- and the result is that the observer on the Moon measures the speed of the light from Chekov's laser cannon moving at 300,000km/s. Both Chekov and the observer on the Moon agree that the light from the laser cannon travelled at 300,000km/s- but they don't agree on how much time elapsed on Chekov's mission!!

When Einstein says that "There is no preferred frame of reference", he means that there is no reference frame that is the "correct" one to view the universe from. There isn't a special frame of reference in which the "official" version of Maxwell's equations operate or all measurements are correct. There is no preferred reference frame from which to view the universe. Any reference frame will work, and none are special.

"Umm, isn't that what you just said? You said a special frame is one where the laws of physics are "simpler", not the only frame in which the laws of physics can be formulated at all. If it's "easier to work with", then yes, it is, indeed, simpler."

A special frame would be one in which all measurements are "official" or in which the "correct" version of Maxwell's Laws operates, or so on. This doesn't exist, and neither does "absolute rest" and the "ether".

"The laws of relativity are not simpler in any frame. But there are other laws. And even hypothetical laws not discovered yet (like those describing FTL). As long as any of those laws are simpler in a frame, it's a special frame."

What are these "other laws" of physics that you are convinced exist? You make it sound like you have a hot line to God and can ask him about the "true nature of the universe".

Milo: "Hey, God, are there any laws of physics that modern science hasn't found yet? Do any describe FTL travel?"

GOD: "Yes, Milo. They are "ominous buzzing sound blanks out wiretap recording". There you've got it."

Milo: "Thanks, God!!"

GOD: "Don't mention it!! Just remember, don't use the knowledge I revealed to you to dominate the field of theoretical physics and win a Nobel prize or to invent FTL travel."

Milo: "Gee, why?"

GOD: "BECAUSE YOU'LL DIE!!!!!!!"

Christopher Phoenix said...

For science fictional purposes, you could postulate limitations on FTL that will keep time travel paradoxes from occurring- but it really is just handwavium. At this point, you're playing it fast and lose with physics. If you do this right, readers probably won't care too much. You can get away with bending the laws of physics, not throwing them out entirely.

Personally, I don't like FTL travel too much. No matter how plausible-sounding a method the writer proposes, the world they create is fundamentally tied to the technologies the characters use. If you keep throwing hyperdrives in your fiction, is it truly "speculative" fiction?

You end up aping other writer's baseline technologies and create universes similar to theirs- fictional universes that are fundamentally inconsistent with our current understanding of the universe. It's the SF equivalent of smoking six packs of cigarettes a day.

Personally, I find actual speculation on how we might reach the stars at sub-optical velocities more intriguing and exciting than made up methods of FTL travel. Actual scientific speculation is always more exciting than made up science.

I think that much of the audience out there- at least the scientifically minded of them- are getting tired of the numerous derivative SF works out there. Take this view from Astronomer Sten Odenwald: What is your main complaint about science fiction in the 21st century?

At a certain point, it just becomes fantasy. Not that there is anything wrong with fantasy, but we are talking about science fiction, which should be trying to create imaginative worlds based on real science instead of perpetually bending the laws of physics.

Damien Sullivan said...

"Not since Robert Heinlein's (1907-1988) Orphans of the Sky published in 1963 has an author thought about long-duration space travel."

Blogger hasn't kept up with SF. Greg Egan, Alastair Reynolds, Ken MacLeod, Ursula LeGuin modulo ansibles, Vernor Vinge [Deepness, "Long Shot"], Joan Vinge (I think; Heaven Belt). Heck, a lot of Larry Niven.

Plus the larger number who still use FTL but have moved from warp drive or hyperspace to wormholes.

Blogger doesn't seem to have a public e-mail.

Christopher Phoenix said...

Damien Sullivan:

I linked to Sten Odenwald's web site to provide an example of a SF readers attitude toward modern SF. I don't know if he provides an accurate assessment of all science fiction for the past 50 years-although I must admit that I haven't seen much high quality SF being written recently, and neither has Winchell at Atomic Rockets.

Doesn't Larry Niven have hyperdrives all over the place in his Known Space series? The ansible and "light speed drive" are pretty much fantasy- and you get the same time travel issues from FTL communication as you do FTL travel.

As for wormholes- these theoretical constructs are probably impossible to build in the real world. No one has shown how to maintain one without the energy of a star and bizarre negative energy states- and it is likely that travelers would be shredded into wriggling quantum spaghetti the moment they tried to travel through it. Scientists don't know how we'd build a wormhole in the first place. We'd have to somehow rip a hole in space. Fast, easy wormhole travel is somewhat unlikely. Creating realistic SF is not just a matter of using the latest scientific buzzwords.

It is quite possible to write an exciting story that doesn't rely on hyperdrives or wormholes. I don't mind bizarre methods of propulsion or exotic physics, but FTL shouldn't be thrown into every SF story just so we can shrink down space to an analogue of the age of steam. On this blog I see plenty of people who dismiss slow interstellar travel and relativistic craft and instead focus on bending physics to get jump drives.

Who's email are you looking for?

jollyreaper said...

I think the risk of "sameness" is really the bigger issue here and it follows for pretty much every genre you can think of.

Hey, I want to tell a fantasy story! Ok, what's it about? Well, there will be a dark lord who wants to conquer everything. And then there will be a good guy who tries to stop him. And there will be some magic object they get that's the source of the dark lord's power. And then they'll have to go and do something to it. And there will be dwarves and elves and dragons and--

Listen, it's already written and it's called Lord of the Rings. Unless you can do a better job of it than Tolkien, why should we care?

The only real reason to draw in a whole lot of familiar tropes is if you plan to use them as a springboard for doing something new. If not, why bother?

There's nothing more desperately boring than a story you've seen a hundred times before and here it comes again. You can see the story beats coming miles away. The novel is lacking in anything novel.

jollyreaper said...

This may be as good a place as any to share.

Iron Sky will be coming out this April. Mother-bleepin' Space Nazis from the dark side of the Moon. From the same people who brought you Star Wreck.

This is the trailer.

http://www.youtube.com/watch?v=kn3cmYJ4Pw4

Leave your hard science at the door, this is a comedy. :)

Christopher Phoenix said...

Jollyreaper:

As you are the most recent in a long line of cynics who claim "The novel is dead!!", I give you no credence whatsoever. ; )

I was referring to SF tech issues rather than derivative stories. I don't have any desire to copy any writer who has come before me- none of them. Even if a writer wrote well, I very often disagree with their outlook and conclusions.

I would never write something "like" Lord of the Rings because I disagree with Tolkien's beliefs and views- very strongly I might add. Tolkien uses his tale to express his belief that knowledge is corrupting and technology is evil. He even shows Gandalf chastising the evil wizard for using a prism to split white light into many colors!! I never knew Sir Isaac Newton was an evil dark wizard. Tolkien made sure to show that technology was evil by showing the industrialized Orks.

Science, the engine of prosperity, is seen as an evil, corrupting influence by Tolkien. The search for knowledge is condemned, and Tolkien instead glorifies utter ignorance as superior. My fantasy story would present the opposite view- ignorance and suppression of learning are the evil.

However, this is all ignoring the fact that Tolkien wasn't exactly original himself. Lord of the Rings is a blatant rip-off of Norse mythology. Sure, Tolkien may have added his own elements, but he didn't pull the setting out of his @#$.

However, Tolkien was not a major figure in my library. I read all of C.S. Lewis's Narnia books. However, while I like C.S. Lewis's books- especially The Horse and His Boy , I don't agree with C.S. Lewis much either- especially his views on space travel. He believed space travel was evil, since humans are corrupt and have no business in space until we are saved, and he expressed his views in his space trilogy. He even called rocket pioneers "very wicked people".

C.S. Lewis's anti-space travel beliefs were very strong. His writing was full of attacks on scientists and on astronauts in particular- which roused the ire of Arthur C. Clarke, especially the passage in "Peleranda" that referred to "little Interplanetary Societies and rocket clubs".

My relationship with the greats of fantasy is not a desire to emulate them, but instead a need to give them a black eye. I love violent analogies. : )

People who write stories with evil people take over the world, dwarves, and elves just liked Lord of the Rings and want more of the same. I think that they missed the point- Tolkien was expressing his views through a fantasy setting, not revealing the wonders of being a dwarf. Setting is just that, setting. The basic values and principles of whoever writes the story shape it much more.

Damien Sullivan said...

I was referring to Odenwald's e-mail, to let him know stuff had been written since 50 years ago.

Niven has technology change in his setting. Later on you have hyperdrive and teleportation and other exotics, but the famous human colonies were all settled by STL. The Kzinti were STL when they attacked, too, though they had magic like gravity drives. Of course, he also had weak psionics, thank you John Campbell. _Protector_ was dueling Bussard ramjets.

He also had non-Known Space: World Out Of Time, Integral Trees.

And yeah, ansibles are magic FTL; being info only they might be regarded as slightly less magic. Certainly different from Star Trek. (near) lightspeed drives are also magic in terms of known physics, but they no longer violate relativity/causality, so big step up there. Plus, for SF you don't always want to get into nitty gritty details which will likely be wrong; assuming we can somehow get from A to B as fast as physically possible is legitimate, more so than simply ignoring Einstein.

(I'd originally assumed Le Guin's NAFAL ships were Bussard ramjets, that being the most physically grounded way to get such speeds, so I didn't mind the speeds, but wondered about the civilization energy budget...)

Yeah, I'm skeptical of wormholes being practical or even possible. But they are things you can get physicists talking about as coming out of general relativity if you squint right, as opposed to completely made up for the convenience of the story, and there seems to have been a big shift to them in written SF; if you're going to have FTL, do it that way.

And you've still got Egan, Vinge, Vinge, Reynolds, Watts, maybe others. Not a lot, but hard SF has always been a tiny niche taste.

Oh, Robert Forward, he wrote after Odenwald's cutoff. Stross, _Saturn's Children_ (not counting stuff so near-future there's no space activity at all.)

As for good new SF, Haikasoru is bringing some solid stuff over from Japan.

jollyreaper said...

I'm not attacking the novel as an artform. I meant it in as a singular example. A novel that's a direct rip-off of other prior works without adding anything new isn't very novel.

Someone who decides to write a rebuttal to the Lord of the Rings by using all of the same tropes with a twist is doing a valid piece of work.

Where I'm saying there's a failing is if someone does exactly what came before without adding anything to it. Westerns have been done time after time. So someone tries to do a new western. Well, are there any interesting characters? Something we haven't seen before? Is it just really good writing, really good action, an excellent and stellar example of the genre? Was there any point or purpose to the undertaking?

If the writer is desperately seeking our attention while having nothing worth saying, was the effort ever warranted?

Damien Sullivan said...

As for Tolkien showing technology as evil, that', uh, a simplistic reading. The hobbits had a watermill (and umbrellas). Both dwarves and Noldor (the non-wood elves we see) are knowledgable and skilled, so skilled it looks like magic. And the orcs aren't really industrialized. Sauron and Saruman are sort of industrial, but that's them, not the orcs, and the sin there is not the industry but the deforestation and pollution (and attempts to conquer and kill people). The value here is "befouling the English countryside so you can have more weapons and unnecessary goods is not a plus".

It's not just industry; the Numenoreans wiped out the huge coastal forests and created wasteland, just for timber for ships. Not their high point. Just as 1950 was not a high mark of industrial environmental responsibility.

The light line was always a bit odd, but you have to remember the context. This is a mind-controlling polluting traitor Isaac Newton who probably runs rape camps to make his soldiers, who say "he gives us man-flesh to eat".

Christopher Phoenix said...

Damien Sullivan:

Niven did have STL travel- but he did have hyperdrives supersede ramjets in Known Space, which is probably enough for Sten to regard Niven's books as not particularly realistic. When Sten says "long duration" space travel, he probably means generation ships traveling at a very low fraction of C.

FTL communication is just as bad as FTL travel from a physics standpoint. I think what Sten wants is a writer who doesn't use any form of FTL ever- a lot of writers seem to assume that some form of FTL travel or communication will be invented someday.

As for nearly-as-fast-as-light drives, those are what Michio Kaku would refer too as a Type-1 Impossibility. We can't build one today, but there is nothing in the laws of physics that says it couldn't be done. Travel at close to optical velocity requires incredibly advanced technology, but it doesn't violate any laws of physics- protons in the LHC travel just below the speed of light, after all.

In fact, all forms of sub-optical star travel, ranging from generation ships to NAFAL ships, are Type-1 Impossibilities. Great engineering challenges, sure, but I see nothing to convince me of the true "impossibility" of these concepts.

You are quite right that you don't want to get into the nitty-gritty of how things are done. You don't want your story to be like the old SF story that predicted telephones that could record conversations and play them back and then showed a character changing the wax cylinder in the phone! Unless you are referencing a specific technology, it is best to not explain Captain Pike's phaser pistol battery works. It just does. ; )

I find research into wormholes fascinating, and if a writer wants to use one for a story, that's ok. Personally, I would probably explore STL travel with all its limitations and glories.

One idea I've always found fascinating are reactionless field drives. Even though these don't seem to be as common today- although I'm sure there are exceptions- some scientists are seriously exploring the idea of a space drive that can produce acceleration without expelling reaction mass. Check out this link. Fundamental breakthroughs in physics are required for breakthrough concepts like space drives.

As Sir Arthur C. Clarke said, the only way to find the limits of the possible is to venture past them into the impossible.

Christopher Phoenix said...

Jollyreaper:

"If the writer is desperately seeking our attention while having nothing worth saying, was the effort ever warranted?"

No. If a writer doesn't have anything interesting to say, than they shouldn't be writing. Sounds harsh, I know- but still true.

I have found one thing on which C.S. Lewis and me both agree. Speculative fiction, rather than being "silly" and "not good literature" as the intelligentsia often claim, matters much more than "realistic" novels that don't explore any new ideas.

It is a strange comment on our age that such a book [Childhood's End, Arthur C. Clarke] lies hid in a hideous paper-backed edition, wholly unnoticed by the cognoscenti, while any 'realistic' drivel about some neurotic in a London flat--something that needs no real invention at all, something that any educated man could write if he chose, may get seriously reviewed and mentioned in serious books - as if it really mattered. I wonder how long this tyranny will last? Twenty years ago I felt no doubt that I should live to see it all break up and great literature return: but here I am, losing teeth and hair, and still no break in the clouds. ~C.S. Lewis, Collected Letters of C.S. Lewis: Volume III, Letter to Joy Gresham, Dec 22, 1953

Damien Sullivan:

"As for Tolkien showing technology as evil, that', uh, a simplistic reading. The hobbits had a watermill (and umbrellas). Both dwarves and Noldor (the non-wood elves we see) are knowledgable and skilled, so skilled it looks like magic. And the orcs aren't really industrialized. Sauron and Saruman are sort of industrial, but that's them, not the orcs, and the sin there is not the industry but the deforestation and pollution (and attempts to conquer and kill people)."

Tolkien had strong anti-technology and anti-science beliefs, as well as a desire to return to the "simple life" as exemplified by the hobbit village. Obviously even hobbits need simple technologies, but Tolkien didn't portray advanced technology in a favorable light. I don't think that human technology is quite the same as what the dwarves and Noldor were using.

The comment about splitting light, and the fact that he portrayed an evil, mind-controlling Sir Isaac Newton with rape camps shows that Tolkien distrusted scientific learning. Sir Isaac Newton was one of the greatest scientists in human history, and Tolkien made a not-so-subtle reference to him as being the seed of evil.

I must make a concession, though. Tolkien experienced the horrors of WW1 first-hand. Science provided deadly new weapons- smokeless gunpowder, automatic weapons, poison gas, etc.- that made WW1 one of the deadliest and most wasteful wars in history. Tolkien also saw industrialization destroy the English countryside. He didn't distinguish between technology and the misuse of technology, and he thought the technology was rapidly filling the world with horror and pollution. That view was not so silly after what he experienced.

The original Star Trek has the opposite view. Star Trek's future society is a (relatively!!) peaceful Kardashev Type-2 civilization. It is made quite clear that humans had to learn to use their increasingly advanced technology in a mature manner, not misuse it for destruction. Science is portrayed as an uplifting, unifying force that opens the door to space- but first we had to overcome our baser instincts, fears, and prejudices. It is this message that ensured Star Trek's enduring popularity.

Thucydides said...

Both Tolkein and C.S. Lewis were devout Christians, and I think a better way to approach their works is as Christian allegories rather than SF, Fantasy or some other genre.

While I am not qualified to render a judgement on their works, I would suggest one reading of LOTR or Perelandra to highlight the Christian doctrine of salvation through Faith rather than Work. Science and Technology are manifestly examples of Work, so salvation from evil, ruin or the will of God will not come from those means, in fact they may become the cause of your demise.

Tony said...

Whew...

It is indeed ironic that somebody stumping for "real" science in SF would invoke Michio Kaku, perhaps one of the biggest fantasists (see Physics of the Future) among public science commentators.

As for the rest, there is truly no new plot or character to be discovered. So the criteria always has to be how good and believable is the human story presnted? And, no, there would be nothing new in STL technology to write about. It's all been done numerous times and in numerous ways. If you don't think so, you simply haven't read enough. Authors who are good starting points have already been named.

Christopher Phoenix said...

Tony...

A lot of hate and disapproval for anyone who mentions Michio Kaku, I see. It's probably warranted for Michio- even though he does make an appealing television personality- but must everyone jump on my neck just because I made a passing reference? I don't agree with everything the man says.

I haven't read Physics of the Future. I was rather unimpressed with Physics of the Impossible, so I didn't read any more of Michio's popular books. He jumps from topic to topic without really explaining much of anything. One moment we are discussing powerful lasers, and then he jumps to tokamaks, and then we are on to the next chapter.

On the other hand, I don't really agree with people who keep throwing around the words "fantasy', "Impossible!!", or (my favorite) "scientific heretic". According to the established scientists a century ago, x-rays were not real, radio had no practical use, heavier-than-air flying machines were impossible, rockets could not move in outer space, need I go on?

I prefer the ruler NASA's "Warp Drive When" website uses to gauge inventions. You can find it at this web address- http://www.nasa.gov/centers/glenn/technology/warp/inspinv.html. It places concepts on a scale ranging from Conjecture to Application. In an attempt to avoid provoking further Michio-bashing attacks in the future, I shall rank various SF inventions on NASA's ruler.

Starships- Nothing in the laws of physics proves that travel between stars is impossible, although certain academics delight in "disproving" the idea of star travel with horribly simplistic back-of-the-envolope calculations. All these noisy naysayers succeed in proving is that numbers can be arbitrarily chosen to give the appearance of extreme difficulty.

Star travel could certainly become a reality in the next few centuries, although it's certainly likely to not be as fast as we would prefer. If we build propulsion systems to travel at 5% to 10% the speed of light, we could reach nearby stars on a travel time of tens of decades to a century or so. Attaining a significant fraction of light-speed would cut down voyages to "mere" decades- so travel to other stars within a human lifetime is consistent with relativity. Seriously, though, concepts for star travel abound and some people spend much of their time researching these ideas- go read the some of the scholarly papers on star travel yourself.

Faster-than-light Travel- Believe it or not, speculation on FTL travel has crept into mainstream physics, placing it at the realm of Speculation on NASA's ruler of advancement. We will need a quantum theory of gravity to find out if we can actually create stable wormholes for interstellar travel or space warps. I'm sure most of you have heard of the speculation on FTL travel- or arguments against it- so I'll move on now.

Continued...

Christopher Phoenix said...

Force Fields- It is probably impossible to create the kinds of forcefields we see on SF stories. In SF, forcefields are an impenetrable barrier that can block physical objects and deflect/absorb blasts from energy weapons like lasers.

The concept of a forcefield seems to be a tightly bounded field of significant magnitude that objects affected by the particular force associated with the field are unable to pass through the field and reach the other side. Unfortunately, none of the four fundamental forces we know of- gravity, electromagnetism, and the strong and weak nuclear forces- are suitable for constructing a forcefield.

The strong and weak nuclear forces only act over subatomic distances in the nuclei of atoms. Electromagnetic fields can only repel charged objects and obey the inverse square law, so we can't confine them into a "wall" of force. Gravity is the weakest force, always attracts objects, and obeys the inverse square law as well. For this reason, I place classic E.E. Doc Smith-style forcefields on the Conjecture portion of NASA's ruler. We know want we would like to do, but we have no idea how to do it.

That said, I can imagine how we might build a "perimeter defense system" that would function as an almost impenetrable barrier. First, I would place a laser-based active protection system around whatever I want to protect. A layer of cold plasma to absorb EMP's would go up next, followed by a layer of hot plasma to vaporize enemy soldiers or projectiles, followed by yet another layer of cold plasma. In this way, I would build up my defensive system in layers- perhaps another layer could protect from biological attacks and poison gas. Not quite a forcefield, but certainly a defensive system that behaves a bit like one.

Laser Cannons and Ray Guns- These are definitely on the Science segment of the scale, with some examples on the Technology segment that are trying to be finally applied on the battlefield. Powerful lasers can blast through steel, and the military is trying to deploy laser weapons to dazzle enemy sensors and shoot down planes.

What about death rays and portable ray-guns? There are two main problems with laser guns. Current lasers are far to bulky, inefficient, and unstable to be used as death rays. Put to much power through them, and the laser overheats, the mirrors crack, the tube melts. The power source is the other big issue. No portable battery pack or generator can supply the intense bursts of power a laser weapon requires- at least not one that doesn't require a truck for transport.

A laser powerful enough to kill a human will fit in a back of a large vehicle, not a holster- and the U.S. already built one. The Mobile Test Unit was a 30Kw electrically excited CO2 laser that was housed in a Marine Corps LVTP-7 tracked landing vehicle. I have read that one of the technicians bragged that "it will go right through you with no trouble". I wouldn't be surprised- 30Kw is more than enough to do real harm to a human.

There is nothing in the laws of physics that says that a ray-gun is impossible. Powerful, efficient laser generators and portable power packs that contain large amounts of energy are required- but that is an engineering problem, not a physics problem. Dr. John Schilling suggests that a pulsed laser beam can incapacitate a human with a kilojoule of output energy.

Continued...

Christopher Phoenix said...

Transporters and Teleportation Devices- These are firmly in the Speculation portion of the NASA ruler. We have no idea how to disassemble in object, beam the information needed to reassemble it across space, and reassemble it at the other end. The amount of information required to describe the quantum state, location, and velocity of every single atom in a human body is mind-bogglingly enormous. The Heisenberg Uncertainty Principle tells us that we cannot measure an object without changing its quantum state, so we can't scan a human and locate every single atom and molecule precisely. Sending all that data in a few seconds is impossible with current day computer rates. We don't know how we could rebuild someone out of raw atoms once the data arrived.

Regrowing an object from digital instructions would take a very long time. Even the smallest objects contain trillions of atoms. Shortcuts might be found, but they would be fatal for organic material. Information would be lost- information that specifies the location of the cells the make up your body!!

Enterprise transporter room. Redshirt materializes on transporter pad- and promptly collapses in a liquified puddle on the floor.

McCoy: "He's dead, Jim!!"

Kirk: "Scotty, what the hell happened!?"

Scotty: "Computer error- the transporter applied bulk transport bit compression when it was supposed to be set to quantum resolution scan. Oh, the poor lad!!

McCoy: "Every atom in his body was scrambled and reassembled in the wrong order!! Humans aren't meant to have their atoms scattered across the galaxy by that molecule-mashing monstrosity of a machine!!"

That's my take on several classic SF inventions.

Damien Sullivan said...

Starships: maybe I'm naive, but http://en.wikipedia.org/wiki/Project_Longshot seems like something we'd have a good chance of building today, modulo high cost. Hardest bit of the propulsion unit is the He3, but we can make that via tritium without having to go mine Saturn. Hardest part of the ship is probably something that'll work for 100 years, and sending humans with any fate other than "look around then die" would be a whole other thing.

Anonymous said...

=Milo=



Christopher Phoenix:

"We have no idea how to disassemble in object, beam the information needed to reassemble it across space, and reassemble it at the other end. The amount of information required to describe the quantum state, location, and velocity of every single atom in a human body is mind-bogglingly enormous."

I put no stock whatsoever in the feasibility into disassemble-and-reassemble-atom-by-atom type teleportation, and I wouldn't trust such a device even if it existed.

Microscopic teleportation could be useful as a means of communication, but not transport of people or goods. The latter will require macroscopic teleportation of the entire cargo in one piece, probably using wormholes.

(I might, however, use the beamed-information-reassemblor for COPYING things, like an advanced fax machine. But I note that nobody ever seriously suggested that all faxed documents should be destroyed immediately after faxing, even though that would make faxes work more like the preexisting postal system people were familiar with.

I might also resort to brain-uploading as a hedge against death, however this is simply picking the less unpleasant option. Even with the ability to reassemble my brain atom by atom if necessary, I'll still try to not die if it can at all be helped.)

Thucydides said...

Project Longshot is making some huge assumptions, starting with the unproven (we can make 3He aneutronic fusion work) to the very difficult (high tech components can last for a century in a hostile environment).

A one way "fire and forget" mission may be possible, but with current technology and knowledge, the ship would have to remain functional for over 1000 years just to mak it to the nearest star...

Damien Sullivan said...

Fusion's a bit funny. It's actually fairly easy to do; you can build tabletop fusors. Plus of course fusion bombs didn't take that long to develop. Developing fusion *reactors*, that generate electricity, is a whole other story, what with plasma's strong desire to leak out.

But Longshot doesn't depend on a fusion reactor, as Daedalus did; it uses a fission reactor to make fusion pulses, in a rocket where plasma blasting out is exactly what's wanted, not a bug. I figure in the worst case, most of the energy is coming from the fission-driven lasers, but the fusion gives the desired exhaust velocity, as a crazy ion drive; in the best case, the fusion adds significant energy to the fuel, so that it approaches being a fusion rocket.

It's a lot simpler and isn't moving at 4% c, but Voyager's lasted 35 years without being designed for it. So yeah, Longshot takes some assumptions, but they seem weaker than a lot of other options. Robust and redundant design isn't obviously the sort of thing that takes centuries.

Tony said...

Christopher Phoenix:

"A lot of hate and disapproval for anyone who mentions Michio Kaku, I see."

Noting an irony is "hate"? I'll have to make a note...

"On the other hand, I don't really agree with people who keep throwing around the words "fantasy', "Impossible!!", or (my favorite) "scientific heretic". According to the established scientists a century ago, x-rays were not real, radio had no practical use, heavier-than-air flying machines were impossible, rockets could not move in outer space, need I go on?"

A century ago? That would be 1912, right?

The first medical X-ray image was made in 1896.

In 1912, news of the Titanic was radioed from the ship itself, using the new international distress signal SOS. I would say that was a practical use.

Heavier-than-air-craft were maybe not an everyday commonplace, but they were certainly real enough in 1912.

Some scientists said that rockets wouldn't work in space. More weren't so silly.

"I prefer the ruler NASA's 'Warp Drive When' website..."

I guess you'll have to put me down as a double-hater, because I don't find Marc Millis very credible.

"Starships"

Not theoretically impossible, in the abstract. In practical terms, it may not be possible for humans. Or, if it is pactically possible, not until we develop a lot more energetic technology than we currently possess.

"Faster-than-light Travel"

At this point, magitech, Miguel Alcubierre notwithstanding. I'd like to see it be possible, but for now it's just an SF plot device.

"Laser Cannons and Ray Guns"

Laser weapons are marginally possible, but I have a hard time seeing them being particularly more useful than guns or missiles of equal impact energy.

Rick said...

Belatedly catching up with this thread!

A fusion drive (of some sort) may be more viable than fusion power production, because as noted having the plasma escape is a feature, not a bug. At least if it escapes in the right conditions. And it doesn't have to produce electric power efficiently, let alone cost-effectively.

Lasers probably won't supplant projectiles for most applications, especially terrestrial ones.

My interest in laser stars is tied substantially to nuclear-electric propulsion, which a) implies a LOT of plug power available, and b) has such sluggish acceleration that diverting drive power to the beam is no real disability.

Flip side, a viable fusion drive might ruin it for laser stars if most of the drive power goes directly to thrust, producing little electric power. And/or the drive produces enough oompf that you want to scoot and shoot at the same time.

Tony said...

Rick:

"A fusion drive (of some sort) may be more viable than fusion power production, because as noted having the plasma escape is a feature, not a bug. At least if it escapes in the right conditions. And it doesn't have to produce electric power efficiently, let alone cost-effectively."

It doesn't even have to produce a positive current flow. If it requires supplemental fission or solar power, well, we weren't trying to generate house current with the thing anyway.

"My interest in laser stars is tied substantially to nuclear-electric propulsion, which a) implies a LOT of plug power available, and b) has such sluggish acceleration that diverting drive power to the beam is no real disability."

The difficulty is that it also implies standing pat and shooting it out with all comers. That's never worked out too well in practice. It has the same built-in handicaps that fixed fortifications do -- all of which tend to inspire finding means of maneuver rather than direct confrontation. Without considerable flank support, these kinds of things turn into embarassing white elefants.

"Flip side, a viable fusion drive might ruin it for laser stars if most of the drive power goes directly to thrust, producing little electric power. And/or the drive produces enough oompf that you want to scoot and shoot at the same time."

Funny thing -- that much "oompf", as you put it, actually makes high power beam weapons more viable, because extra power generation might just be a marginal increase to payload. requirements. Of course, the same argument applies to truly pornographic amounts of kinetics. Which just goes to show...the more power you have, the more options you enjoy.

Anonymous said...

Rick said:"Flip side, a viable fusion drive might ruin it for laser stars if most of the drive power goes directly to thrust, producing little electric power. And/or the drive produces enough oompf that you want to scoot and shoot at the same time."

Only if your fusion drive doesn't need a fission reactor to power it...;)


Ferrell

Christopher Phoenix said...

@Tony

Hmmmpphh.... I'll have to check my dates more carefully next time. I'm just asking that you keep an open mind- but not so open your brain falls out.

I was referring to the noted British physicist Lord Kelvin, founder of the Kelvin scale. He stated that heavier than air flight was impossible, X-rays would prove to be a hoax, and that radio would have no practical use. I probably got the wrong date from something associated with Michio Kaku- he's really bad with checking his information.


Sorry!!!!

Some rather prominent scientists said rockets wouldn't work in space, and the New York Timesclaimed that Robert Goddard lacked the "knowledge daily ladled out in high school".

That's enough to get anyone depressed. Robert Goddard actually had to test small rockets in a vacuum chamber- like someone trying to prove the Bifeld-Brown asymmetric capacitor produces thrust in a vacuum- to convince other scientists that rocket thrust wouldn't drop off in the vacuum. Read the Wikipedia article.

What about Mark Millis do you not find credible? He hasn't claimed to invent an antigravity drive. All he's done is start a workshop at NASA to explore concepts like field drives and FTL travel from a scientific standpoint. Or do you think you should be able to tell every scientist what he/she should do with their time?

I never said FTL travel was real- I said that modern physicists are exploring some ideas like space warps and wormholes that might be used for FTL travel. The most likely result of this research is that these ideas, if they are possible, will be rather difficult to put into practice. Don't tell me you don't see physicists speculating on FTL travel every now and then.

What's "marginally possible"? Something is either possible, or it isn't. If you meant impractical, say "Laser weapons are probably impractical." To be honest, I was talking about handheld ray-guns had heavy laser cannons, not near-future weapons.

The way lasers will be used in the near future does not resemble the near instantaneous incinerations caused by heat beams or the instantly fatal death rays of pulp SF. The actual uses of lasers on the battlefield include dazzling and blinding sensors and some point defense applications. That's the near future, though. In the farther future- the possibility of having a high power laser weapon you could hold in your hand is very real. It probably won't supplant projectile weapons for decades after its invention, though- ordinary weapons are just too common and simple.

Real "ray-gun" weapons are going to be somewhat messier than Hollywood shows. Laser beams generally heat what they hit- imagine having some sort of beam burning a hole through your body and vaporizing portions of your internal organs!! It is also possible that laser wounds will be as bloody as knife wounds if expanding steam rips surrounding flesh. A microwave beam could cook a human soldier from the inside until he exploded. Lasers in the infrared frequency are invisible- so you might not even see the beam that kills your companion, or its origin point. One thing is clear- real blasters will be a heck of lot more messy than SF's ridiculously clean "disintegrators".

Rick said...

Not even then, unless fusion adds only a fairly modest increase to total drive power.

The key predicate for a laserstar is an onboard electric power supply in the tens or hundreds of megawatts. (It is the electricity that matters - nuke-thermal propulsion is irrelevant to powering a laser.)

If a fusion drive needs only a small fission reactor to spark-plug the fusion reaction, it won't be enough for uber-powerful zaps. (Which are the whole point of the laserstar.)

On the other hand, even if you have a big badass fission reactor, but the fusion drive boosts this into gigawatts of thrust power, you start to get some real maneuverability, which can make throwing kinetics even better than laying down zaps.

Everything here depends on the balance of things.

Anonymous said...

It occures to me that if you need a fission reactor to power your engine, then it should be relitively easy to increase the size of the reactor to provide enough electricity to power a BAL for your Laserstar. The greater mass would affect your ship's performance, but would be a way to rationalize laser heavy combat.

Ferrell

Rick said...

Yes - if you want laserstars you can still have them. But nuke electric propulsion particularly favors laserstars, due to the combination of lots of electric power supply and sluggish thrust performance.

Thucydides said...

Notice how any thread that goes on long enough becomes one about space warfare? ;)

Any useful space warship (or any ship which aspires to the sort of performance seen on TV shows) needs to combine high thrust with high ISP. The only known drive that can do this is nuclear pulse drives (AKA ORION), or putative pulsed fusion drives (possibly laser or electron beams imploding D2 fuel pellets).

ORION drives have power self contained in the pulse units, so would either be missile carriers or have separate monster reactors for the laser, while pulsed fusion drives with magnetic thrust chambers could use induction to power beam weapons so long as the drive was active.

Rick said...

Yes, I have noticed that. Unless the thread is about space warfare in the first place, in which case it merely accumulates outsized comment traffic.

ORION is, in a sense, nuke thermal on steroids, while 'elegant' self-sustaining fusion is nuke electric on (a different kind of) steroids.

ORION drive is not at all well suited to laser stars - if you have an onboard reactor it will need big radiator wings, one more thing that will have to be braced against that bumpy ORION ride.

A fusion drive probably has some electric generating capability ... if you're willing go sacrifice some or all acceleration while zapping. But if you have a torch level drive generating terawatt-level thrust power, you might be able to draw off a mere gigawatt or two with no effect on thrust performance.

Of course, then the question is how long ships last in an environment of gigawatt beams and hundred km/s kinetics.