Upper limit of habitable worlds in one solar system?

October 8, 2005 10:41 PM

After seeing the recent movie Serenity, and having my intelligence insulted by how poorly thought out the universe is (it's all supposed to be taking place in one solar system, with hundreds of habitable worlds), I was wondering what the theoretical upper limit of possible habitable worlds in a single solar system is. Assume the normal Earth-like worlds, and moons of Jovians. [Slightly More Inside]

My other thought was what if you took a supergiant star like Betelgeuse and had some brown dwarfs in orbit around it. What's the upper limit on that? Also, does anyone know of any good webpages that would do these calculations for you?

posted by geekhorde to science & nature (70 answers total)

Or programs, for that matter.
posted by geekhorde at 10:42 PM on October 8, 2005

Why is it in "insult" to have dozens of worlds? No one ever said they were naturally occuring. These were terraformed; the details are sketchy on purpose (the series never mentioned exactly what happened to "the earth that was").

Firefly Wiki
posted by RavinDave at 10:52 PM on October 8, 2005

Nope. Not dozens. At least a hundred. Said so in the movie.

Also, terraforming is not magic.

Also, in any solar system, there is a limited space where water can exist in a liquid state, perhaps the most important requirement for human life. Outer worlds would be more cold because they would receive less sunlight than the inner planets. Viable ecosystems require energy and the proper conditions to exist.

Also, I know why Whedon was doing this. He wanted to avoid using FTL. But guess what? He was writing a show set in SPACE!!!! ARGH!!!

Also, if there was no FTL, how the hell did the humans get there from EarthThatWas?!?

Basically, it all smacks of very little forethought. Thus, insulting my intelligence, because I HAVE thought about these things.

Caveat: this did not keep me from enjoying the movie. It just annoys the obsessive SciFi geek in me.
posted by geekhorde at 11:01 PM on October 8, 2005

The Drake Equation might help you answer, albiet indirectly.
posted by Mach5 at 11:07 PM on October 8, 2005

I'm not sure why a show set in space has to have FTL. It's definately possible to travel to other stars without it. Just takes awhile!

I haven't seen the show or movie but could their solar system be the same as Earth's, just in a future where the Earth had been destroyed or something?
posted by 6550 at 11:08 PM on October 8, 2005

Granted. It is possible to travel from one star system to another without FTL. However, if you factor in the idea of terraforming worlds (and how long does that take, by the way?) with where the hell do all the colonists live while their waiting for their worlds to be habitable, it just triggers my bullshit meter.

The star system in question cannot be the Solar System. The numbers don't add up.

It just strikes me as lazy writing, and I expect so much better from Whedon. He should have talked to a real Sci Fi author, or even a physics grad student.

Anyway, I suspect you could get close to 30 habitable worlds in a single solar system if you had a single large massive supergiant and a companion star, and perhaps a group of brown dwarf stars in orbit. The brown dwarfs could have moons that might fit into the right temperature ranges, but would probably have crazy weather systems. Like Category 8 hurricanes and stuff.
posted by geekhorde at 11:16 PM on October 8, 2005

Humans lived in some kind of stasis, I'd assume. I don't think it's unreasonable to assume there is some solar system with dozens of habitable planets and moons, based on solar heat availability as the only criterion. Who knows how terraforming works. The thing about sci-fi is you're not supposed to get too worried about how it works, you're supposed to enjoy the human drama that plays out in an interesting new setting.
posted by knave at 11:28 PM on October 8, 2005

So... what sci-fi show, exactly, doesn't insult your intelligence?

ST:TNG had its Heisenberg compensator, which was just as much of a cop-out. And don't even get me started about the deflector dish.

Farscape never even tried (IIRC) to explain starburst. Nor any of the other strange, strange things that happened.

Babylon 5 had hyperspace, a technology that was never explained (and actually poorly understood by the beings that used it). Although, I have to admit that JMS was very careful is most other respects.

Stargate SG1 has... well, the stargate network. Do they ever offer an explanation that doesn't involve made up terms?

I can't even remember what explanation Sliders had, but come on: a remote control device that opens a stable wormhole? You've got to be kidding.

The Dune series has its space folding, which involves some heavy drug use and a navigator in a trance state (up until the last two books). Once again, never really explained.

My point is that you're focusing on a completely irrelevant thing. I've watched the TV show twice and I couldn't have even told you all the planets were in a single solar system. You know why? Because it's almost completely irrelevant to the story. It's not a plot detail people are meant to sit and contemplate.
posted by sbutler at 11:28 PM on October 8, 2005

Firefly is a pretty light sci-fi anyway. The sci-fi is more backdrop than in the foreground.
posted by TwelveTwo at 11:32 PM on October 8, 2005

geekhorde, it does sound unpossible. Reading sbutler's post, I can't think of an sf shows or movies that I would call hard sf, which it sounds like what you would like. Do any exist? Much sf seems more like science fantasy to me.
posted by 6550 at 11:33 PM on October 8, 2005

And in his other series, he had vampires and shit, which are like totally unbelievable. I mean, dude. They have psychics, and spaceships that aren't 99.9% fuel tank, and artificial gravity without rotation or constant thrust, and all that stuff. And it's the density of habitable planets that has your panties in a bunch? I think you need to have your intellectual-insult detector calibrated.

IANA astrophysicist. But I'd have to think that the theoretical maximum is Very High. The first easy thing to do, if you were a god trying to maximize the number of human-habitable worlds, is just chuck extra Earths onto Earth's orbit, separated by enough angular distance not to screw with each other.

Then do the same with other orbits in the water belt, just far enough from Earth orbit not to screw with Earth-orbit worlds noticeably, fiddling with the planetary chemstries enough to keep from getting our Venus and Mars.

Then go to the jovian planets and give them lots of moons that you can heat up either by their own core radioactives or through inductive heating, like Io.

That ought to get you at least a hundred habitable worlds.
posted by ROU_Xenophobe at 11:39 PM on October 8, 2005

Just to be clear, the exact bit from the movie is:

"We found a new solar system. Dozens of planets and hundreds of moons. Each one terraformed, a process taking decades, to support human life."

The first nine minutes of the movie are online, so you can watch and listen for yourself (linked page contains embedded movie player).

Personally, I had imagined that the colonists left Earth in a state of suspended animation to travel the long distance to their new solar system. And you could also imagine them being awakened in waves, as new planets & moons were terraformed and ready to support them.

This aspect of the movie seemed believable enough to me.
posted by medpt at 11:42 PM on October 8, 2005

I imagine this would be a difficult question to answer because a) there's a small ring (well, really a shell, since we're dealing with three dimensions) where planets could sustain life naturally, and b) the more bodies you toss into orbit around a star, the more complex the gravitational interactions, and so who knows how many planets you can fit into that ring without it all going to hell. And then you throw in the possibilities of terraforming, etc., etc. and you're basically looking at "who knows?"

As to what this has to do with Serenity, I would say you're right, the state of the universe hasn't really been fleshed out (though to be fair, the exact line is "a new solar system; dozens of planets; hundreds of moons." See for yourself.) I think this is on purpose; the only bit of information in the earth-that-was preamble that's of any use at all is the fact that we don't know what happened to Earth. Otherwise you can basically assume there are a bunch of planets with stuff on it, and don't worry about where they are or whatever.

Even on the series, flight time was rarely mentioned. The only time I remember it coming up was in "Out of Gas," where I think it was said that the trip they were taking in that episode would take a couple of weeks, during which they would be in the middle of nowhere. So it's entirely possible there were other systems out there, and that there's no real FTL.

on preview: uh, what medpt said about the "dozens of planets" line.
posted by chrominance at 11:52 PM on October 8, 2005

If you're wondering how he eats and breathes
And other science facts,
Just repeat to yourself "It's just a show,
I should really just relax."

There could be any number of different reasons why there are many planets around one star. For instance, we can obviously note that all the ships have artificial gravity, which honestly we could interpolate to mean that they have all kinds of other magic powers.

Think about what we could do 500 years ago, and think about telling someone from 1505 about genetic engineering, or nuclear reactors, or going to the moon. They might say to you, "You're insulting my intelligence."
posted by thethirdman at 11:59 PM on October 8, 2005

I think this is fairly unlikely. Planets don't come into a solar system pre-formed. They coalesce over time from gaseous clouds. So while it is quite possible to imagine a stable solar system with 100s of planets if you just plunked the planets there, I think it is much less likely when you realize that such systems form in a very specific way.

I know an astrophysicist -- and I have heard him mention computer simulations in this field. So I know it's done, but I don't know your answer, and the stuff I might find would be very dense and take me too long to decipher.

The astrophysics book I have spends most of its time on stars, sadly. But rock-like planets only form within a certain band, and gas planets in another. Most objects lie in an equatorial plane, reducing the amount of available space. On the whole, I suspect the differential equations that would be used to simulate the formation of a solar system would not favor the formation of hundreds of planets.

But it is all theory -- we only have scant evidence of the existence of planets outside our system. We know almost nothing about any solar system but our own.
posted by teece at 12:10 AM on October 9, 2005

Wil McCarthy (sf writer and rocket scientist) tackled this, concluding:

Of course, the odds of such a thing occurring naturally are slim indeed, and the chance that all 100 planets, when terraformed, would end up looking exactly like California is ... well, zero. Whether Firefly lore admits it or not, the Alliance system has got to be an alien artifact, left behind by Nivenesque Ringworld Engineers for their own obscure purposes. I guess you can't take the sky from those guys, either.

posted by Zed_Lopez at 12:16 AM on October 9, 2005

This debate can go on forever. We're still surprised at stuff we discover in our own solar system. Almost every planet or moon here has some associated "mystery" to it which defies what we knew before. How our own solar system even came into being is not a solved problem.

So, sure its possible. It is after all the future which as history shows, has been beyond the imagination of even the most imaginative thinkers.
posted by vacapinta at 1:02 AM on October 9, 2005

Also to hit back (in a friendly way) at the original poster:

What's the upper limit on that? Also, does anyone know of any good webpages that would do these calculations for you?

There is no calculable upper limit. That would presuppose we know a lot more about this than we do. So, in a sense, your initial assumption is itself naive.
posted by vacapinta at 1:05 AM on October 9, 2005

Robert A. Metzger's sci-fi novel CUSP features a solar system with hundreds of Earth-like worlds; the system in that novel was assembled artificially by powerful and mysterious entities.
posted by mbrubeck at 1:08 AM on October 9, 2005

So, sure its possible.

This is only correct in a very vapid way. Using what we know now, there are very good reasons to believe that this is quite unlikely. There are no good reasons to believe that it is likely.

Saying that we are, of course, unsure is not nearly the same thing as saying "sure, it's quite possible."

It's like saying, "yes, it is possible to win the lottery every single day of the year, buying only one ticket a day."

It's a true statement. It would also strain credibility to actually read a book where that happened. Our knowledge is not as limited as you let on, vacapinta.
posted by teece at 1:14 AM on October 9, 2005

Whedon said in an interview: "They’re really close together. You’ve never seen a planet cluster like this one. It’s a little planet village. If you start asking my science questions I’m going to cry."
posted by futility closet at 1:41 AM on October 9, 2005

Two quick points:

1) The original poster is claiming to be the thoughtful, obsessive one, but did not pay attention to the movie, and when many people quote the movie and link to proof, he never says as much as "oops". I don't know what that means.

2) You never get this kind of coherent-universe satisfaction from the Buffyverse. Trying to do it is just a waste of everyone's time. What suits the story, applies. Vampires can smoke cigarettes, but not give CPR? They can't be seen in mirrors, but they can be captured on film? Who's Spike's sire again?

The way it works, he's said before, is that nobody says "wouldn't it be cool if Giles turned into a demon?". It works like "Giles feels old and unattractive and like nobody understands him; what's the Buffyverse way of displaying that? How about he changes into a demon which only speaks a demon language".

I don't know if Joss even gave any thought to changing his rules when he came to create a second world. I'd very much like to hear him asked that in an interview.

But I'd suspect that, if a character in the Fireflyverse was some day required to be feeling very very lonely, then, yes, they'd end up in interplanetary space, and so on.
posted by AmbroseChapel at 3:42 AM on October 9, 2005

Sounds like intelligent design to me,
posted by blue_beetle at 4:33 AM on October 9, 2005

The way it works, he's said before, is that nobody says "wouldn't it be cool if Giles turned into a demon?". It works like "Giles feels old and unattractive and like nobody understands him; what's the Buffyverse way of displaying that? How about he changes into a demon which only speaks a demon language".

I've never watched any Joss shows. After reading that, I certainly won't, so thanks for the "warning," AmbroseChapel. And I'm NOT an sci-fi geek who cares all that much about the science. Like Joss, I care about character. But I CAN get distracted by plot holes and poorly designed worlds. I want to be able to focus on the characters without constantly thinking, "Wait! But that totally contradicts what happened in last weeks episode!" If I'm thinking that, then I'm thinking "the writers made a mistake," which means I'm thinking about the WRITERS, not the CHARACTERS. Which means that I'm conscious that it's all made up. When fiction really works for me, I sink into it and (for long stretches of time) believe it's real. Anything that disturbs this "reality" sucks.

It sounds like Joss is not playing fair -- not doing his homework. I totally understand that he wants to focus on character. But GOOD writers find ways to do that withOUT violating their own worlds (and they understand why this is important, even if the point of the story isn't the details of the world itself). Good sci-fi writers get the science right (as-much-as possible), just like good historical-fiction writers don't pepper their stories with anachronisms. Whether a story is hard or soft sci-fi should have nothing to do with it. The soft variety should be lighter on the tech and science than the hard variety, but both varieties should strive to perfect whatever tech and science they contain.

Sure, sometimes a single, major magical premise is useful: what if someone got caught in a time-loop in which one day repeated over and over again? How would that affect character? If this trick is established boldly and early-on, it MIGHT fly in a sci-fi book. (If you want to use magic to explore character, why not use fantasy instead of sci-fi? Still, even in fantasy, you have to play by rules. Magic can happen, but the magic must be consistent.) But writers owe their readers the respect of trying as-hard-as possible to get things right. Given the Buffy and Firefly examples noted in this thread, it sounds suspiciously like Joss didn't try very hard -- like he COULD have found ways to tell these stories that would have satisfied his character needs AND didn't involve world-violations and logical errors. But he didn't care. It "makes him cry" when people bring up science. That's a little unfortunate for a SCIENCE fiction writer.

Whenever I get into these discussions, I'm always made aware that some people aren't bothered if vampires can smoke but not give cpr. And they tend to think people like me are purposefully poking around, trying to find fault. I suspect this is just two different kinds of minds at work. Some people can watch one episode (or even one scene) without linking it to the rest of a series, to what has gone before. But my mind races. It does this without effort and it's not under my control. When I -- and people like me -- watch a show, it's like we're seated in the middle of a giant wiki with hyperlinks to all the other episodes. So we really appreciate it when writers are careful. And, at the risk of sounding self-important, writers should writes for US. People who don't really care about story logic aren't bothered when the logic is correct -- they just don't care about it one way or the other. We do care. So if you write for us, you serve both kinds of people. If you write for them, you needlessly lose a big chunk of your audience.
posted by grumblebee at 6:38 AM on October 9, 2005 [1 favorite]

Nope. Not dozens. At least a hundred. Said so in the movie.

Hmm.. it's a Joss Whedon creation. He's a guy who made a whole series about a chick who kills vampires. He doesn't have a long track record for realism. I think you need to put Firefly pretty low down the totem pole for sci-fi realism. It's a fantasy story, barely above LOTR in terms of realism.
posted by wackybrit at 6:38 AM on October 9, 2005

Good sci-fi writers get the science right (as-much-as possible)

No, they don't. That's simply false, or at least unreconcilable with any reasonable list of good SF writers.

Good SF writers get as much of the science right as is convenient with whatever story they want to tell, and tell a good story.

Good space opera writers -- and Firefly is well into space opera territory -- operate under the standard that big, obvious departures from anything remotely physically possible are just fine and dandy so long as they make shit blow up real good or are otherwise cool. This goes way the hell back to Doc Smith.
posted by ROU_Xenophobe at 6:55 AM on October 9, 2005

Good sci-fi writers get the science right (as-much-as possible)

No, they don't. That's simply false, or at least unreconcilable with any reasonable list of good SF writers.

Sure, you're right. The term "good sci-fi writers" is meaningless unless you interpret it subjectively or through some arbitrary criteria (writers I like; writers some committee likes). But I thought I made it clear in my post how I was defining "good," which was writers who do their homework and, when possible, get ALL the details right. Sure one can "make shit blow up," create compelling characters and explore them fully, AND get the details right. It just takes some hard work which, it sounds like, Joss doesn't care to do. Since his interest is character (and maybe explosions?!?), he SHOULDN'T get the details right if this detracts from character (or explosions). But is this necessarily so? Has he really tried his darndest to make EVERYTHING work?
posted by grumblebee at 7:14 AM on October 9, 2005

As far as I know, Whedon is the only director since Kubrick to offer a major sci-fi movie (let alone TV series) in which there is no sound in space. For getting that right, I'll forgive him any other minor transgressions.
posted by schoolgirl report at 7:19 AM on October 9, 2005 [1 favorite]

For me, sometimes is good enough for acknowledging the magic without having to explain it. For example, I don't think Firefly explains Serenity's artificial gravity but they demonstrate that it exists. (I'm only a bit into the series, tho.) Firefly is a fun watch and I'll give Joss et al some slack because the series is a pretty fun watch.
posted by sexymofo at 7:40 AM on October 9, 2005

thought I made it clear in my post how I was defining "good," which was writers who do their homework and, when possible, get ALL the details right

You did make that clear. It's just that there are exactly zero SF writers (of any note at all*) who do that.

*That is, I don't doubt that you can come up with John Q. Bloznik, who published two stories in a local Louisville fanzine in 1963. But nobody who matters.
posted by ROU_Xenophobe at 7:40 AM on October 9, 2005

ROU, are you serious? There are zero SF writers who TRY to get both character and science right? I remember reading those Mars books by Kim Stanley Robinson. He may have made mistakes, but it certainly seemed like he had worked very hard to do exactly what I'm talking about.

Also, I think plot contradictions are MUCH more important to stamp out than bad science. I can accept the transporter on "Star Trek," even though it's nonsensical. It's established early on and then boldly used. So I just accept it and move on. (It would be MUCH worse if they suddenly inserted it into the story halfway through.)

What I CAN'T accept are those episodes where they discover some astoundingly useful advanced technology and then never mention it again -- even when it would be useful. What I can't accept is all those episodes where people get trapped on a planet because the transporter breaks, and somehow everyone forgets that they have shuttlecrafts. That has nothing to do with sci-fi. That's just bad storytelling. They invent a shuttlecraft in one story (or find an advanced technology in one story) because it serves THAT story and then drop it in another story, because it doesn't serve THAT story. And yet they also ask us to believe that all the stories take place in the same universe. That's just sloppy writing. Good writers know that if they invent something in chapter one (or episode one), they owe it to their story and their readers/viewers to follow that invention's ramifications throughout the rest of the story.
posted by grumblebee at 7:51 AM on October 9, 2005

I'll give Joss et al some slack

This is what's so weird to me about these discussions. It's as we're trying to decide whether to let Joss into the Good Writer's Club. You'll cut him some slack and let him in; I won't.

But I don't think it's about that at all. It's about uncontrollable, gut reaction. If I'm torn out of a fictional world, I'm torn out of it. If you're not, you're not. It has nothing to do with cutting anyone some slack. I guess you can say, yes, I'm occasionally torn out of the world by a logical error, but I'll still be Joss's friend and invite him over for dinner. Fine. But can we ask him please to write better?

I disagree with ROU (if I understand what he's saying) that there are no good writers who attend to the details, but ultimately even THAT doesn't matter. If there are no good writers, then there are no good writers. It's not about who we canonize or call good or cut slack -- it's about how we react to a story. How we honestly react.
posted by grumblebee at 7:57 AM on October 9, 2005

Good SF writers get as much of the science right as is convenient with whatever story they want to tell, and tell a good story.

Exactly.

Also, why do we have to get explanations of how things work in a sci-fi story?

"Warm up the ion drive and let's get the hell out of Spidertopia!" said Captain Phantasmoid to his robot dog.
   "Bark! As you know, Captain, the ion drive does not need to be warmed up, because, unlike a solid-fuel rocket, it works by accelerating highly charged particles through an electrostatic field!"
   The robot dog did not get Captain Phantasmoid's joke, because he had not been programmed to. As a robot, he could only react according to an instruction set he had been programmed with.
   Programming is when a series of unambiguous statements are made in a language which can be interpreted by a machine.
posted by Hildago at 8:24 AM on October 9, 2005

I think grumblebee has an expectation for a certain kind of modern western rationalism in the story telling. Most story telling we come across is rational in that way, so the fact that it is not required is kind of surprising.

Personally, I like rationalism... Does that mean I won't like this Joss Wedon's work?
posted by Chuckles at 8:37 AM on October 9, 2005

It's not about who we canonize or call good or cut slack -- it's about how we react to a story. How we honestly react.

Plenty of people reacted pretty well to the premise of the Firefly universe. Certainly to the so-called Buffyverse as well. All of your criticisms are dead-on, but you're not admitting the simple truth that people can disagree on esthetics and both be correct.
posted by Hildago at 8:39 AM on October 9, 2005

but you're not admitting the simple truth that people can disagree on esthetics and both be correct.

"The term "good sci-fi writers" is meaningless unless you interpret it subjectively..."

"I suspect this is just two different kinds of minds at work. Some people can watch one episode (or even one scene) without linking it to the rest of a series, to what has gone before. But my mind races."

"If I'm torn out of a fictional world, I'm torn out of it. If you're not, you're not."
posted by grumblebee at 8:48 AM on October 9, 2005

I remember reading those Mars books by Kim Stanley Robinson. He may have made mistakes, but it certainly seemed like he had worked very hard to do exactly what I'm talking about.

Those are the books where scientists try to heat up Mars by putting windmills on the surface that power electric heaters. And where a zeppelin in a storm uses windmills to generate electricity to power its props, and generates forward thrust this way.

Mistakes that serious and obvious mean that he wasn't trying very hard at all.

If you bounced off of Firefly, fine. People like different things, and I'm not fond of the western setup myself. But I don't think you can reasonably claim to have bounced off of it because of some principled objection to bad science.
posted by ROU_Xenophobe at 8:58 AM on October 9, 2005

Most story telling we come across is rational in that way, so the fact that it is not required is kind of surprising.

Not "required"? Who requires anything? The god of stories? Nothing is required. There are just stories and people's reactions to them. If you set up something in chapter one and then contradict it in chapter two, some people will have a negative reaction (and some won't). I am one who will. This is because I read (and watch) to escape into another world. There are other reasons to read, but I'm not interested in them. I can't escape into a world full of contradictions, because the contradictions remind me that it's all a fiction (because I'm aware that the writer made a mistake, which means I'm thinking about a WRITER, hence the world is fictional, not real).

In the real world, if we're told that pigs can't fly and then see a flying pig, we go searching for natural explanations. Maybe the pig is on wires. Maybe pigs CAN fly. Maybe I'm insane. In a story, there's an easier explanation: the writer made a mistake. So that's where the mind goes -- or at least my mind.

I wish it wouldn't. I have no desire to find holes in stories. I want all stories to suck me in and take over my mind and my emotions. It's sad when this doesn't happen.
posted by grumblebee at 9:01 AM on October 9, 2005

Those are the books where scientists try to heat up Mars by putting windmills on the surface that power electric heaters. And where a zeppelin in a storm uses windmills to generate electricity to power its props, and generates forward thrust this way.

I'm not enough of a scientist to understand the problems, so the stories worked for me. Which is all I ask. I don't really care if the science is real or fake -- since my interest is character. I care that I BELIEVE it's real, so that I won't be alienated from the story, believing the writer made a mistake. This effect -- of real science, real history, real whatever makes sense for the genre -- is going to have more stringent requirements for different people. A physicist may expect more rigor from a sf story than a lay person. If the writer aims to please the physicist, the lay person (who doesn't care) will also be pleased, so TWO people will be pleased. If the writer aims to only please the lay person, the physicist will be alienated, so only one person will be pleased.

Ultimately, it's only the result that matters (if Robinson goofed, he goofed), but I do believe -- based on interviews -- that he was TRYING to get the science right. He just failed. ROU, I thought you were claiming that no SF writers were trying to do this. If so, I think you're wrong. I think Robinson, Clarke and many others are TRYING. Maybe they are failing. Maybe it's inevitable that bad science will creep into stories. But it's good to TRY, because that means LESS bad science will creep in. And less is better, because fewer people will be alienated.
posted by grumblebee at 9:09 AM on October 9, 2005

grumblebee, for someone who has professed to never seeing a Whedon* show, you're really gung-ho set on telling everyone how bad they are.

Given the criteria you've mentioned for what makes a "good" story, I think you'd love Firefly (especially if you check out the series first, movie second). I've not watched Buffy, for various reasons, but when I saw Firefly I thought it was wonderful. Though some of the posters above have said that Whedon cares more about the characters than he does about the science, you shouldn't take that to mean that the science is poorly done. I'm a sf-stickler myself, and I thought that the show worked hard and succeeded at creating an environment that made sense. (To clarify: when I say it made sense, I mean that I never really had to think about why things were happening in the environment around the characters. My feeling of immersion in the story was never checked by my confusion regarding some apparently broken physical law.)

Anyway, my point is twofold: (1) the original poster's complaint is off the mark, because the story doesn't actually have a system with "hundreds of worlds", though it does involve "hundreds of moons"; (2) you simply won't find science fiction elements used as a deus ex machina, or other "bad storytelling", when watching Firefly (and I agree that what you describe happens in many other shows all too often). Again, I can't speak about whatever might happen in Buffy, because I haven't watched it, don't really want to. This isn't a fanboy rant about Whedon. It's a defense of Firefly, which was very well written.


* I'm not on a first-name basis with the man, unlike some others here, I guess...
posted by voltairemodern at 9:09 AM on October 9, 2005

voltaire, the science is important to me, but what really not as important as consistency. For instance, if there's an impossible machine on page one, I would RATHER it continue onto page two than for the writer to correct his mistake on page two. Of course, I'd rather the impossible machine wasn't there at all, but given a choice between bad science and story contradictions, I'll ALWAYS choose bad science. So the Buffy stuff about smoking/cpr scared me much more than the hundreds of worlds. I could probably get over that if it was established early and was internally consistent.

I'm not trying to diss a guy whose work I've never seen. This is important to me for practical reasons. I actually had some Whedon stuff on my netflix queue. After AmbroseChapel tipped my off about the inconsistency in Buffy, I removed the DVDs. I realized that his stuff was not for me. (Though maybe Firefly is different, as you suggest.)
posted by grumblebee at 9:17 AM on October 9, 2005

In response to grumblebee...

I think it's worth pointing out that Whedon's shows actually do a great job towards establishing a sense of continuity. That's probably what I like most about them. If you get completely hung up on minor details like the reflected visibility of vampires, then you might not enjoy it, sure. But if you care about character development and recurring situations and references that span the course of the entire series, then his shows really can't be beaten.

He's definitely not as careless in his shows as you seem to assume he is (without even having seen any of them).
posted by jimmy at 9:26 AM on October 9, 2005

Grumblebee: IMHO you're being very foolish--there are errors in the "Whedonverse" but Buffy et al are FAR more consistent (and more concerned with building on concepts introduced in previous episodes/seasons) than ANY "genre" shows I've seen before or since.

Yes, there are errors that the previous posters pointed out, but Joss *is* good at world-building and explaining. He does choose a certain point at which disbelief-must-be-suspended but I think he does it in a brilliant and interesting way.

Your kneejerk reaction will make you miss out on some great writing and great stories. Please rethink!
posted by bcwinters at 9:29 AM on October 9, 2005

medpt writes "And you could also imagine them being awakened in waves, as new planets & moons were terraformed and ready to support them. "

Besides which if there is one thing humans are universally good at it's making more humans. Given just modern birthing and early childhood medical care coupled with the drive to produce 10,15,20 children per couple a society could rapidly fill all available space.

grumblebee writes "That's just sloppy writing. Good writers know that if they invent something in chapter one (or episode one), they owe it to their story and their readers/viewers to follow that invention's ramifications throughout the rest of the story."

The big grip of the SW fans boys and the prequels boils down to this kind of afront, well that and goofiness like Jar-Jar.
posted by Mitheral at 9:32 AM on October 9, 2005

jimmy and bcwinters, that's good to hear!
posted by grumblebee at 9:35 AM on October 9, 2005

To go back to the original poster's question: no, they did not locate a solar system with hundreds of habitable worlds. They located a solar system with a few dozen planets and hundreds of moons -- which, based on our knowledge of our own solar system, doesn't seem particularly implausible.

Only one or two -- or perhaps none -- of the planets in this solar system was habitable for humans. So the galatic frontiersmen used their superior futuristic technology to "terra-form" planets and moons into habitable environments. If one were to nit-pick about scientific realism in the Firefly 'verse, I think this magical method of turning a hostile environment like Jupiter into something Earth-like would be the place to start. Think about it for more than 30 seconds, and it begins to seem about as implausible as, say, hyperdrive.

Still, you've got to give Whedon credit for trying. He wanted to create a sci-fi universe without FTL travel, and rather than say, "Oh, lucky them! They found all these nice planets in one convenient solar system," he created a plausible, albeit far-fetched, method of explaining how all these habitable planets got so close together. As a whole, the universe is consistent, but still not completely fleshed out. Revealing bits of the mysteries is just part of the fun.
posted by junkbox at 10:12 AM on October 9, 2005

I'm not enough of a scientist to understand the problems, so the stories worked for me.

It shouldn't have worked for you unless you never took, or have completely forgotten, high school physics and chemistry. Errors that serious imply that KSR has never even heard of thermodynamics or entropy.

Ultimately, it's only the result that matters (if Robinson goofed, he goofed), but I do believe -- based on interviews -- that he was TRYING to get the science right.

Sometimes people fail badly enough that you can't take seriously the idea that they were actually trying. Goofs as obvious and serious as KSR's in Red Mars fall into that category for me. Not that I didn't like them; I like the RGB Mars books immensely. But if you care about getting the details right, as you claim you do, you should detest them.

ROU, I thought you were claiming that no SF writers were trying to do this. If so, I think you're wrong. I think Robinson, Clarke and many others are TRYING.

They only try insofar as it makes a good story, and when a good (to them) story requires jettisoning sound science or reasonable extrapolations of scientific knowledge, good SF authors chuck them out the window. Case in point, Clarke and racial memories from the future and large-scale psi powers in Childhood's End, both of which are complete claptrap that advance the story.
posted by ROU_Xenophobe at 10:14 AM on October 9, 2005

I remember reading those Mars books by Kim Stanley Robinson. He may have made mistakes, but it certainly seemed like he had worked very hard to do exactly what I'm talking about.

Sure, and they were boring boring boring with not even one likeable character, and they put me off ever reading his work again. I can't fathom people who liked these books, or even those who actually read the second one. Why would you read the second one when the first was so awful? Masochist?
posted by kindall at 11:08 AM on October 9, 2005

Creator's manufacture the worlds in which their stories take place, then set events in motion to affect the characters they design. Thusly, the worlds they create don't have to resemble our own.

At the end of the day, we're talking about a character-based space opera with strong western elements set five hundred years into the future. And hell, nothing says that this future is actually our future. Any speculative future, regardless of the strict attention paid to hard scientific detail, is still only the product of imagination. Even if Whedon decided to take his series down a path limited by scientific reality as we understand it today, we-the-audience would still have to accept a new set of fictional rules to understand and appreciate the scenarios presented.

What matters with any show or movie or play is that the material maintains a since of internal logic. Can you or I hop in a Plymouth and drive to Mars? No. But the crew of the Serenity -- for the sake of this television show -- can. The show establishes its own rules, then has to follow them.

24's Jack Bauer can get across Los Angeles in fifteen minutes or less at any given time of day, virtually ignoring the idea of traffic, rush-hour or otherwise.

Even so-called reality television sets up an internal logic all its own.

Queer Eye gives the appearance that the Fab Five show up at the straight guy's house in the AM, make him over (including his entire house) through the afternoon, then drop him off in his new life before dinner. Actually, the show is taped over a three-day period. The TV audience sees what the show wants to present.
posted by grabbingsand at 11:27 AM on October 9, 2005

Not to inject some actual science into this discussion, but Bode's Law would seem to predict that hundreds of Earth-mass worlds couldn't peacably coexist in the same solar system.

Even if they'd been 'terraformed'. Unless 'terraforming' means 'dragged into place by an extremely advanced civilization using high-energy ion drives and tethered mini-black-holes,' which I don't think was part of the Firefly plot.
posted by ikkyu2 at 11:28 AM on October 9, 2005

also, dont forget its a hundred PLANETS its a hundred MOONS.


Didnt Clark ignite Jupiter in one of his books? Firefly has earth normal gravity on every ship, so they have some crazy control over physics.
posted by Iax at 12:15 PM on October 9, 2005

Not to inject some actual science into this discussion, but Bode's Law would seem to predict...

Bode's law isnt science. Its conjecture. Fascinating conjecture but conjecture nonetheless.

It has no causal explanation. It just seems to be an observed property. Again, falling into the realm of something we dont know. My point earlier was that its difficult to generalize at all from a data point of one. We only really know anything about one solar system and by all accounts (there's life here) one that is already atypical.
posted by vacapinta at 1:54 PM on October 9, 2005

I don't really understand the problem here. If you are worried about the consistency of the Firefly/Serenity universe, then I can say that it is very consistent - certainly far more consistent than Star Trek. They don't suddenly invent a tachyon transporter in one episode to avoid getting blown up, and suddenly forget about it in the next episode.

Now, if you're worried about the scientific plausibility of Firefly, well, it's obviously not all that plausible. A solar system with dozens of planets and hundreds of moons, with most of them terraformed? I think not. The habitable zone around a star is not that wide, and no amount of terraforming will allow you to have that many habitable planets unless you squished their orbits together very, very close. If you did that, I suspect you might find problems with their orbits and there might be too many rogue asteroids and comets floating around. It's very implausible.

But let's face it, do you really care? I mean, this show posits some sort of artificial gravity wherein the people on the ship can walk around like normal, without the use of rotating segments. It also assumes that you can terraform planets in a few decades. From a scientific point of view, I find that far more unlikely than a system with a big bunch of planets. But I don't care, because it doesn't really matter. As many people have pointed out, Serenity does not adhere to real-world physics (as we understand them) but it does adhere to its own laws.
posted by adrianhon at 3:37 PM on October 9, 2005

grumblebee, where is the inconsistancy? Couldn't the 'tons of worlds' thing be the 'magical' part of the story?
posted by delmoi at 7:26 PM on October 9, 2005

Ok, first to Ambrosechapel who wrote:


"1) The original poster is claiming to be the thoughtful, obsessive one, but did not pay attention to the movie, and when many people quote the movie and link to proof, he never says as much as "oops". I don't know what that means."

No one disproved a damn thing. The idea of at least dozens (certainly over 30) habitable worlds in one solar system stretches the limits of believability to anyone who knows a small amount about astrophysics, etc. Second, I've been busy. So sue me. I had to sleep and eat and talk to friends and stuff. Real life. It's that annoying thing that comes between internet posts.

Second, to ROU_Xenophobe, who says my panties are in a bunch, you rock. I totally disagree with you. But you made me laugh, so you rock.

To Voltairemodern, who wrote:

"(1) the original poster's complaint is off the mark, because the story doesn't actually have a system with "hundreds of worlds", though it does involve "hundreds of moons""

No. You are wrong. A moon is a world. The distinction is academic. Every so called 'moon' that we've seen has had apparently Earth normal atmosphere and gravity, ergo, they are about the size of the Earth. Thus, a 'world' so to speak. There are 35 listed on the Wiki, and probably more were going to be written in for the series. So my number of a hundred is probably conservative, in my opinion. Again, there are a limited number of places that you can place an Earth-like world around a star, whether it's in the type of orbit that Earth has around our sun (that's one planet, right there), or theoretically, you could place them as moons around a gas giant. But that many? But some of those listed are called planets.

Anyway, I'm not saying that Whedon isn't a good writer. That's not my quibble. Maybe he's a lazy Sci Fi writer, but not a bad writer. I've enjoyed his stuff. He gets characters very well. My quibble is with the fictional universe that he has set it in, which simply will not work, not without major justification, IMHO. This may not detract from the overall work to you, or 'draw you out of the story' as it were. It does for me.

Part of what I'm complaining about here is the dumbing down of Sci Fi that's been going on for years, and I think this is just another example. I don't care how good the characterization is. The idiocy of the setting is like fingernails down a mental chalkboard to me. Telling me that the setting is that way for the sake of the story just makes me want to puke.

Anyway, not really my original question. My question was what the upper limit of habitable worlds is, factoring in gas giants' moons and such. Maybe I should have written upper 'practical' or 'plausible' limit.
posted by geekhorde at 7:41 PM on October 9, 2005

And we have begun to observe other solar systems. Granted , most of the ones we've observed have giant gas giants in very close orbits around their primaries. But we do have some data coming in.
posted by geekhorde at 7:43 PM on October 9, 2005

> I was wondering what the theoretical upper
>limit of possible habitable worlds in a single
>solar system is.

There are several limiting factors:

*Power available to you

*materials available to you

*Technology available to you

*Time available for the project

*Orbital room required between bodies

If you want strictly natural systems, then I doubt if you'll get over one or two per system. In our own sytem (our only known specimen) we have one habitable body out of a hundred or so large rocky bodies. This suggests the the Serenity system was manufactured, rather the way we manufature islands. Reference the Jumeirah islands at: http://realestate.theemiratesnetwork.com/developments/dubai/world_islands.php

Power:

The project will require signifigant amounts of energy. You would have to collect mass, much of it possibly lumped into gas giants, and move it in a controlled fashion to the habitable zone for that star. Then you will have to form it into carefully sized lumps, each with a precise orbit, size, spin, rough temperature, and mix of ingredients. Solar sails, sails the size of Australia, would suffice for moving things back and forth within the system. I don't think they'd do for mining gas giants.

Materials:

I think we can assume that this system started out with the neccesary materials, perhaps they mined a Kuiper type belt. The presence of lots of rock doesn't violate anything we know about solar systems.

Technology:

Addressing only the terraforming question, there is nothing in physics as we understand it that prohibits moving large masses back and forth within a solar system. If you want to give them gravity control, something that may be possible, (we don't know yet) it would make the project much easier. Nowadays we can create light, magnetism, and electricity pretty much at will. If they could do the same with gravity (Hey, Spindizzies!) it would simplify the creation and maintenance of the project.

FTL (Faster Than Light Travel)

You don't need it to get around within the system. You also don't need it to get there, any more than we need to travel faster than the speed of sound to cross an ocean. Maybe the original colonists got their slowboats cranked up to an average speed of 1/10th of C and spent a couple centuries on the ride. So what? We have people, entire nations, who would sign up for such a trip today, if they got a whole world of their own at the end of the line. What you do need FTL for is to make it easy to write exciting stories. Lack of FTL would also explain why they don't know what's up back at old Earth. Maybe nobodies come from that way for a few centuries.

Time:

500 years is long enough to colonize such a system, but not to build it. Ergo, it was there when they arrived.

Spacing:

I think this is the question you were focusing on. The answer is that we don't know. The math involved would be fantastically complex. If you put your worlds in pairs or subgroups it would simplify things. As an example, the Earth and moon can be treated as one body gravitationally, at least if you don't get too close. A related question is how long you want them to be safe, and if you expect to be there for maintenance.

Mercury for example, appears to not be permanent, it's orbit is unstable. If you have gravity control your initial setup can be less precise, because you can observe for a few centuries to get good figures, and then tidy up as required.

If the humans in the Serenity system are not maintaining it, and it was bulit with maintenance assumed, you could get a whole seasons worth of subplots out of slowly developing problems as the various worldlets start to slowly drift out of alignment.


>My other thought was what if you took a supergiant
>star like Betelgeuse and had some brown dwarfs
>in orbit around it. What's the upper limit on that?

This is the same question, and should have the same answer.

>Also, does anyone know of any good webpages
>that would do these calculations for you?

We would address this question through differential equations. Lots of them. There are a variety of DE packages out there, but you would have to work out the problem yourself, or find someone to do it. It's not a standard question.

My personal opinion is that there is ample room for a few hundred carefully placed rocky bodies to orbit within the habitable zone of an star.
posted by Ken McE at 7:44 PM on October 9, 2005

Thanks Ken McE. Best answer so far.

I wonder if you could have a ring of worlds spaced in the same orbit so that they all fit into each other's Lagrange Points?
posted by geekhorde at 7:57 PM on October 9, 2005

That's called a Kemplerer rosette. The puppeteers from Ringworld lived on a rosette without a central sun. Here are some numerical simulations.

12--48 Earths in Earth orbit, plus 12--48 less-gassy Venuses in Venus orbit, plus 12--48 gassier Marses in Mars orbit, makes for a lot of real estate.
posted by ROU_Xenophobe at 11:00 PM on October 9, 2005

This thread was made much less enjoyable by grumblebee's attempts to moderate (and it wasn't even his thread!). Fie, grumblebee.

Larry Niven is one of the hardest of the hard-science writers -- but of course he was also one given to trying to work out "scientific" explanations for time-travel and teleportation, and then work stories around the "physics" that he devised. Thought experiments, for fun. If you believe, as I do, that it's unlikely that either will ever happen (unless the singularity folks are right ...), then you'd have to chuck out every story he ever wrote around those concepts. But you don't because they're very enjoyable stories -- thought experiments with characters and narrative. Ultimately that's the best way to view any kind of speculative fiction.

For the longest time I had no truck whatsoever with the horror end of the genre; it's only recently that I've begun to understand how it fits into the same matrix, partly because of writers like Whedon (and the new Doctor Who). I could accept fantasy; I could accept hard sf. But somehow I couldn't accept horror's convergence of realistic and supernatural representations. By contrast Star Wars is beholden to no such rules because it's unabashed science fantasy -- and Lucas knowingly places it there. Firefly is a little more grounded than most space opera, but it's still space operat nonetheless. I'm willing to forgive it a few dodges in favor of story than I am narrative dodges.

Niven has a little anecdote about getting the facts right. His very first published story involved Mercury, and in fact turned on the then-"fact" that Mercury was tidally locked with the Sun. Between the time that Niven sold the story and its publication, Mercury was found to rotate independently of the Sun. pwn3d! He was able, after that, to take a more sanguine approach to getting the facts right, and yet he still has such a reputation among sf authors.

So, no, I'm not gonna slam him for this one.
posted by dhartung at 11:41 PM on October 9, 2005

Somewhat off-topic, but there's a wonderful book called "Wooden Spaceships" about a binary planet system - two planets that share an orbit and rotate around each other. These planets are so close that they share an atmosphere (at the "bottleneck") and travel between them is possible on very primitive rockets, hence the title.

Our own Earth-Moon system is tantalizingly close to being a binary planet system. The moon is relatively massive (compared to, say, any of Jupiter's moons relative to Jupiter).

And returning to the topic at hand, throwing in a couple of binary planets or inhabitable moons would certainly make it more plausible to get up to dozens of worlds.
posted by zanni at 12:23 AM on October 10, 2005

He was able, after that, to take a more sanguine approach to getting the facts right, and yet he still has such a reputation among sf authors.

And the first edition of Ringworld still had Earth rotating the wrong way.

For what it's worth, I felt like the question of "how many planets are there in the Firefly system?" (and "how did the Terrans terraform them?" and "why do they have artificial gravity but still wear bonnets?") was pretty much avoidable in both the series and movie. Joss Whedon is not Hal Clement (whose Mission of Gravity I personally take to be the ür-hard-s.f. book), but he states his premises in the first show and then runs with them; it's not scientifically plausible, but it's reasonably internally consistant.
posted by snarkout at 5:27 AM on October 10, 2005

Larry Niven is one of the hardest of the hard-science writers

Nah. Known Space has hyperspace (two kinds!), indestructible hullmetal, stasis fields, psychics, artificial gravity, "gravity polarizers," not quite indestructible Ringworld material, genetically-determined luck, telepathic control of others... These things do not a hard-SF writer make. Bob Forward writes hard SF. Arguably, Greg Egan does sometimes (Diaspora, Distress maybe), if you allow stories that have One Big Departure Point. But not Niven.

What Niven does is get a few big, salient details sort-of right, making lots of other mistakes and ignoring lots of other issues along the way, but you don't notice them immediately for two reasons. First, because the descriptions of the big, salient details he got sort-of right create enough credibility to paper over things. Second, because he tends to go straight to traditional tropes that people are comfortable with when he needs a piece of Magic Tech. Also, Niven is congenitally incapable of writing a character who would not be at home in 1985 LA.
posted by ROU_Xenophobe at 6:39 AM on October 10, 2005

A moon is a world. The distinction is academic. Every so called 'moon' that we've seen has had apparently Earth normal atmosphere and gravity, ergo, they are about the size of the Earth.

Thats were I would say you are wrong.

Look at the firefly ships, the gravity generators dont take up a large fraction of them, so whats to say that the moons cant have some sortof of thingy to make them have higher gravity, Will McArthy did that with his squozon moon.
posted by Iax at 1:41 PM on October 10, 2005

Ok Iax. Didn't think of that point. Good point there.

Although, not sure of the energy requirements of these 'gravity generator' things of which you speak.

Ok, I take it back. While I found the setting unbelievable, I have really enjoyed thinking about this for the last few days.

I like the Kemplerer Rosettes idea there ROU_Xenophobe. Might have to think about that one. And maybe try to use it in a story of my own.

I'll try and check out Wooden Spaceships, zanni. Ever read Rocheworld? Similar idea, but the life on one of the planets is based on ammonia/water.
posted by geekhorde at 2:59 PM on October 10, 2005

THERE ARE SOME SPOILERS IN HERE!

There are two questions here:

1. Is it possible for there to be that many worlds?

2. Is it possible for us to live on them?

Answers:

1. Yes. While proper "M Class" planets only tend to appear in a very small band around a star, there are many many other kinds of orbital bodies. Jupiter has 16 moons, and according to google, Saturn has 46. That's 62 possible worlds right there.

2. Maybe. That all depends on what you assume is possible via terraforming. It is likely that, in the Firefly universe, terraforming is not only a transformative process but a maintenance process. When the crew lands on Miranda, Mal makes note of the fact that the atmosphere is normal and that the gravity is earth normal. In this statement, there is at least the implication that the terraforming process maintains not only atmosphere, but gravity as well.

Further lending credence to the idea that terraforming is a maintenance process is the fact that the scientist on "the video" is discussing a drug that is being added to the air-processors. If terraforming were a one-time deal, then a planet with ten million people (which this planet supposedly had) doesn't need air processors, so it's stands to reason that terraforming is an on-going thing - which makes the terraforming of particularly nasty worlds more likely because the assumption that it will be maintained is already present.

It should also be noted that coreward planents (core meaning towards the sun) are generally more lush and habitable than the outer planets. This is (probably coincidentally) good science for two reasons: one, coreward planets will be closer to the so called "M-class" band where habitable planets exist anyway, making the amount of terraforming required to get "Earth like" far less. Two, the closer you are to the sun, the more energy you're going to have available to power the terraforming process. I don't know if you've noticed but many of the outer planets were desolate holes just barely capable of sustaining life.
posted by jaded at 7:12 AM on October 11, 2005

>Known Space has hyperspace
>(two kinds!), indestructible hullmetal,

If I recall, the indestructable hullmetal was neither metal not indestructable. You simply had a hull-sized object that was essentially a single molecule. (or was it like an extended single atom??) The bonds of the material to itself were strong enough that almost nothing could tear them apart.

Regarding hyperspace, it might be out there, we don't know yet. If it could be usefull is a seperate question.

>artificial gravity, "gravity polarizers,"

We know that natural gravity exists, and the amount varies from place to place. We don't really understand it well enough to know if it will or will not be possible to tinker with it. We know that *we* can't, but there's still a lot of work to be done in physics. Artifical electromagnetic radiation can be polarized, so why not speculate that artifical gravity could be too?

>not quite indestructible Ringworld material,

It was stronger than anything we can build, but so what? It was destructable if enough energy was applied to it. The part that bugs me is that it partly blocked neutrons.

> proper "M Class" planets only tend to appear
>in a very small band around a star,

In a natural setting, yes, certainly. This is an artificial setting so you could start with one band in the traditional equatorial orbit, add a second band tipped at say a 10 degree angle, time it so they alternate passing by one another, add your next band tipped at a 20 degree angle, lather, rinse, repeat.

If it was me, I'd start with the equatorial band because it would give the fastest results for the least time and energy (Assuming matter in the Serenity system is distributed basically like the matter in our system) If the Builders did this, it would give you one ring of planets that have the "best" ecologies, because they have had time to mature fully. (of course what the Builders considered "best" we might consider a hellish nightmare, I don't know)

These equatorial worlds would be likely to have remnants of builder artifacts. (If one assumes they built them to live on) The system should also have some whopping big machinery scattered around out in wide stable orbits. They would have kept it around in cold storage in case later someone ordered a moon, a spiffy decorative ring system, a top up of their air or water, a little climate adjustment, any warranty work, that kind of thing.

>Look at the firefly ships, the gravity generators dont
>take up a large fraction of them, so whats to say that
> the moons cant have some sortof of thingy to make
>them have higher gravity, Will McArthy did that with
>his squozon moon.

OK, if the ships have AG (artificial gravity), then the worlds can too. This means you can have smaller usefull planets. Unfortunately, these smaller worlds are inherently unsafe in that the gravity could fail. An Earth sized world is inefficient in that perhaps 99.99% of the material is unavailable, and is used for nothing but gravity production and heat storage. Although less efficient, it is safer because natural gravity does not seem to be able to fail.

>It should also be noted that coreward planents
>(core meaning towards the sun) are generally
>more lush and habitable than the outer planets.
>This is (probably coincidentally) good science for
>two reasons: one, coreward planets will be closer
>to the so called "M-class" band where habitable
>planets exist anyway, making the amount of
>terraforming required to get "Earth like" far less.
>Two, the closer you are to the sun, the more
>energy you're going to have available to power
>the terraforming process.

If you assume the biology is solar powered, like most of ours is, this is very reasonable.

>I don't know if you've noticed
>but many of the outer planets were desolate
>holes just barely capable of sustaining life.

Another explanation might be that the Serenity sun, like ours, is getting warmer over time, which is slowly pushing the habitable zone outwards. (Ours is doing the same thing, someday Mars will be warm). This would mean that the outer worlds have been positioned as spares, places to move to as the star warms and the inner worlds become uninhabitable. Humans don't think this far ahead, but then we don't terraform entire star systems either.
posted by Ken McE at 5:36 PM on October 11, 2005

I didn't mean Hard SF, the purist genre, I meant hard sf, the opposite to soft sf. Niven's reliance on stock characters is typical; you'd never mistake him for LeGuin. Niven is hard sf in the sense that scientific conundrums are often at the heart of his stories -- he cares about who built the Ringworld and how, but he cares very little about why or what they were all about. (Indeed, he almost certainly doesn't write about the Ringworld builders -- in the first book, anyway -- because he can't imagine them.) It's an MIT engineering exercise with a novel strung around it. Aliens like Nessus exist mainly for echoing back the author's view of humanity, not for any kind of expansive dialogue. His technologies may be "fantasy" but he does a fine job of imagining them out as social tools.

But this isn't a Niven thread; it's about Whedon. I find it instructive that he doesn't worry about such details, yet he's managed to construct a remarkably internally consistent universe -- even if there are some whoppers at its basis. I really like that his stories don't have Treknobabble deus ex machina solutions, and there's no reset button -- two Trek Bible items that made a hack of anyone writing for them. I don't think that having that explanation at hand really makes a difference to the stories, which are essentially about people. He's clearly writing 2005 people, but he isn't hamhanded about making his stories "modern-day allegories". They're just stories about people. That's part of his brilliance and despite any issues I have with the series I think that's why Firefly struck such a chord with so many viewers.
posted by dhartung at 9:28 PM on October 11, 2005

This thread was made much less enjoyable by grumblebee's attempts to moderate (and it wasn't even his thread!). Fie, grumblebee.

My apologies to dhartung and anyone else I irritated.
posted by grumblebee at 4:16 PM on October 12, 2005

Can't. Control. Fist. Of. Pedantry.

Mercury was found to rotate independently of the Sun

While it's not tidally locked in a 1:1 rotation:revolution resonance, neither is its rotation independent of the sun's -- it's tidally locked in a 3:2 rotation:revolution resonance, a situation which is stable due to the eccentricity of Mercury's orbit.

Ah, I feel much better now.
posted by Zed_Lopez at 12:00 PM on October 13, 2005