dystopic dystopic

bussard ramjets, cryonic stasis, and exoplanetary colonization

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bussard ramjets, cryonic stasis, and exoplanetary colonization

what will it take?

from GalCiv2 Forums
hello everyone,

i'm a bit of a writer, and i can't help but feel drawn to science fiction. that shouldn't be surprising.

lately i've been reading up a great deal on theoretical physics, exobiological speculation, and all that. i was dismayed at first to learn that the chances of faster-than-light travel being physically possible are slim. it was also pretty discouraging when i sat down and looked at the actual speeds that'd be required to traverse sizable parts of the galaxy in a single conscious lifetime. it was a kick when i was down to learn about how difficult terraforming probably would be. but the more i've been learning, the more i've been excited about telling a different kind of science fiction story.

to draw an analogue to our world, the thing that made both the european colonial age and the modern process of globalization have been technology. it's not that we couldn't go to various places around the world before, it just cost too damn much to make anything worth it. i got my BA in sociology, and these sorts of things interest me.

if FTL travel isn't possible, then more than likely it'll be too damn costly to ever colonize beyond our own solar system as the way it's been envisioned in most of the celebrated scifi universes. But there are examples such as Arthur C. Clarke's Songs of a Distant Earth or Sid Meier's Alpha Centauri where humans colonize to escape destruction on earth.

recently i had the chance to meet both Kim Stanley Robinson and Geoff Ryman. Robinson is a hard scifi writer after my own heart; the Mars Trilogy is a really interesting look at our first attempts to colonize within our own star system. Ryman was actually more interesting to talk to, though. maybe because few people have ever heard of him (i was only there because i work at UCSD where he was being hosted). but i actually got to talk to him. he said he thinks we probably won't ever leave our galactic neighborhood.

i'm interested in writing a hard scifi story (or series) myself. i'm interested from a sociological point of view: what would drive us to colonize space? from a writer's point of view, i want to keep the earth around, so i'm not interested in a flight from disaster. what would societies be like after colonies were established? trade would be difficult, but not impossible. same goes for war.

while i'm certainly interested in contributions along those lines, i'm also interested in learning more about the hard science and engineering behind interstellar travel. i've got a lot of questions i haven't been able to answer through wikipedia and google alone. but i'm not about to list them all here.

it seems like a discussion about real ("real") colonization and space travel could use a place on these boards.

i'll kick it off. i've been reading up on propultion especially, and bussard ramjets seem like the most economically feasible option since they gather their fuel as they go - perhaps especially if it could be hybridized with another form such as antimatter-catalyzed fusion. the wikipedia article on bussard ramjets describe that they'd probably need what is essentially a magnetic funnel or ramscoop to gather interstellar hydrogen as propellant.

The mass of the ion ram scoop must be minimized on an interstellar ramjet. The size of the scoop is large enough that the scoop cannot be solid. This is best accomplished by using an electromagnetic field, or alternatively using an electrostatic field to build the ion ram scoop. Such an ion scoop will use electromagnetic funnels, or electrostatic fields to collect ionized hydrogen gas from space for use as propellant by ramjet propulsion systems (since much of the hydrogen is not ionized, some versions of a scoop propose ionizing the hydrogen, perhaps with a laser, ahead of the ship.) An electric field can electrostatically attract the positive ions, and thus draw them inside a ramjet engine. The electromagnetic funnel would bend the ions into helical spirals around the magnetic field lines to scoop up the ions via the starship's motion through space. Ionized particles moving in spirals produce an energy loss, and hence drag; the scoop must be designed to both minimize the circular motion of the particles and simultaneously maximize the collection. Likewise, if the hydrogen is heated during collection, thermal radiation will represent an energy loss, and hence also drag; so an effective scoop must collect and compress the hydrogen without significant heating.


talk about kick-butt imagery! spirals of heated gas careening towards a ship only to be fused and expelled in a jet plume? sweet.

anyway, i've written enough, and i hope it hasn't put anyone off. some of the the community here has proven to be very well read with regard to these kinds of science, so i thought it'd make a great topic for discussion: all things related to space exploration and colonization with reasonable extrapolations of current technology.

my biggest point of curiostiy was with respect to ramjets, so i'll take the kickoff: could the spiral motion of the inbound gas somehow be harnessed to artficially generate gravity by rotating the ship, instead of producing drag?

any volunteers?

final words: i hope no one minds my double-motive. i won't try to steer any dicussion, though if things quiet down i might pose more general questions to keep it going; i encourage anyone interested to pose your own!
off-topic
436,407 views 930 replies
Reply #726 from GalCiv2 Forums Top
thus the only thing keeping us from going faster is fuel then. in space that is.
Reply #727 from GalCiv2 Forums Top
Well, even in space there is some resistance (interstellar medium ring a bell?), but for the most part, yes, our fuel is the limit. There is also the issue of G's a human can safely undergo, but I'm not sure if that has really been a limiting factor yet ("G" is a measure of acceleration; 1 G is equal to the acceleration caused by gravity, 9.81 meters per second or 32.174 feet per second, so if you experience 2 G's, you would feel twice as heavy, etc).
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Reply #728 from GalCiv2 Forums Top
lol. use E-85 fuel, it's good for the envirionment.
Reply #729 from GalCiv2 Forums Top
thus the only thing keeping us from going faster is fuel then. in space that is.
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so if you have enough fuel, eventually you can go faster than light?

I would imagine there would be a point where the speed of the material blasting from the thrust rocket would become too slow (relative to spaceship speed) to provide further acceleration?

What i mean is, that if you drove fast enough down the highway then fire a gun behind you, the bullet would simply fall to the ground, it would have neutral speed.... but relative to your car the bullet would still be moving very fast!
Reply #730 from GalCiv2 Forums Top
so if you have enough fuel, eventually you can go faster than light?
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Ah you bring up a good point. Relativity says that as velocity of a vessel approaches light speed, the mass of the vessel increase proportionately (that's the theory in a nutshell, anyways). So an engine that produces a constant force will eventually produce negligible acceleration due to this increase in mass (F=ma, therefore F/m=a; if F is constant and m continually increases, F/m approaches zero).
Reply #731 from GalCiv2 Forums Top
So an engine that produces a constant force will eventually produce negligible acceleration due to this increase in mass (F=ma, therefore F/m=a; if F is constant and m continually increases, F/m approaches zero).
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Oh well, just figure out how to convert the extra mass into energy for the rocket!
Reply #732 from GalCiv2 Forums Top
Oh well, just figure out how to convert the extra mass into energy for the rocket!
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gravity sling shot. if the mass of the ship increases as it goes faster then a gravity sling shot will be very useful in converting the extra mass into energy.
Reply #733 from GalCiv2 Forums Top
Oh well, just figure out how to convert the extra mass into energy for the rocket!
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It's not that simple. I suppose it's more accurate to say the ship gets denser. Essentially, each atom is getting heavier, not because it is accumulating more atoms, but the particles themselves are just...heavier than before. So converting "extra" mass into energy would be to digest the ship itself, which is obviously not a good idea.
Reply #734 from GalCiv2 Forums Top
lol. use E-85 fuel, it's good for the envirionment.
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in the short term, this is true. it releases less heavy particulate, carbom monoxide and general toxins into the air. but if we were to convert the world's engines all to E-85, the soil errosion caused by overfarming of corn to derive the alcohol would have a worse net effect on the environment than burning fossil fuels do at this rate.

it's the same problem with recycling. sure, it means we don't need to mine for more metals or process more plastics or cut down more forrests for paper products. but the energy it takes to recycle materials comes in large part from fossil fuel sources, which means in some senses recycling is actually worse for the environment.

really, the best thing we could do would be to get off chemical fuels entirely.
Reply #735 from GalCiv2 Forums Top
but the energy it takes to recycle materials comes in large part from fossil fuel sources, which means in some senses recycling is actually worse for the environment.
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this is correct but it is also wrong. at least for aluminum which i have heard on tv commercials only takes 10% of the energy to recycle compared to new.
Reply #736 from GalCiv2 Forums Top
really, the best thing we could do would be to get off chemical fuels entirely.
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mm at least give us permission to breath and eat!
Reply #737 from GalCiv2 Forums Top
you could (partially) solve some electrical enery problems with solar panels. let me explain.

I can think of at least three or four major deserts where solar powerplants could be built, Sahara, nevada, australia, etc.. With the desert being huge and since there's almost never any cloud cover, we could put alot of solar plants there and make a lot of energy from them.

Plus if every house and car had at least one solar panel on them, they could recharge energy that they need, while getting the energy they can't create from their desert companions.

Alot of people say they wouldn't work because it's not always sunny out or daytime. WRONG! The earth rotates and it's always daytime on one side of the earth. By the time australias solar powerplants turn off, nevada's solar energy plants will start cranking out electricity.
Reply #738 from GalCiv2 Forums Top
Sahara, Nevada, Australia, etc..
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Sahara would be a good one for this due to its size.

Nevada is cloudy more than you think.

i don't know about the Australia one.

and you missed the biggest desert Antarctica. of course i would hate to go out and clean those panels off.
Reply #739 from GalCiv2 Forums Top
and you missed the biggest desert Antarctica. of course i would hate to go out and clean those panels off.
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the polar regions wouldn't make very good sites for solar power collection because of low efficiency: the light comes in at such a low angle and travels through much more of the atmosphere. "desert" just means it never rains, not that it's hot, or dry, or sunny.

clouds have less of an effect on solar radiation than most people think. i remember hearing that a solar cell runs at about 65% efficiency in cloudy weather of what it does in sunny weather (in the same location). water scatters light more than it absorbs it.

but yeah, i wasn't trying to preach environmentalism or anything, more just free associating.
Reply #740 from GalCiv2 Forums Top
I think the problem with Solar as it stands now compared to other power sources, is that it isn't very efficient when taking into account the pure eletrical output compared to the relative size (or number) of solar panels needed.

For example, solar cars have been produced, but they have limited abilities (speed, cargo capacity, power) compared to typical Gas (or hybrid) cars. The University I graduated from has a coal power plant. The entire facility's foot print is about the size of 2 football feilds. Imagine how much more area would be needed to produce similar power with panels.

Now I'm not against solar power at all, but even if we covered all the buildings with panels, I doubt it would cover the electrical needs of the world. Not to mention it would be very expensive to build buildings that are structually sound enough to support the extra weight.

I think Solar is a great idea, don't get me wrong, but I don't think it would be a total cure. With a planet like Earth, one half of the planet (the day side) would have to provided power for the entire world. Transmission issues not withstanding, I simply don't think that our solar technology is advanced enough at teh moment to do this.

Would solar be a good idea for a future colony? Sure! Since the colony is being built from scratch, we can build infastructure and use design accomodations to make the most out of solar power or any other power source for that matter. Buildings cold be oriented for maximum sunlight, spacing and colony layout could be maximized to reduce or make the most of heat from transmission, etc. It'll probably be the cheapest, safest option for smaller space stations and ships to generate consistent electrical power.
Reply #741 from GalCiv2 Forums Top
I think the problem with Solar as it stands now compared to other power sources, is that it isn't very efficient when taking into account the pure eletrical output compared to the relative size (or number) of solar panels needed.
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all we need in this is as much research as we have done in the gas engines. remember fords wife was driving a solar car.
Reply #742 from GalCiv2 Forums Top


but yeah, i wasn't trying to preach environmentalism or anything, more just free associating.
End of quote


Your not preachy on the enviroment you do listen to other peoples points quite well.

Reply #743 from GalCiv2 Forums Top
you could (partially) solve some electrical enery problems with solar panels.
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denyasis. I said it could solve some of them not all of them.

i remember hearing that a solar cell runs at about 65% efficiency in cloudy weather of what it does in sunny weather (in the same location).
End of quote


See? even in cloudy weather, they will still produce electricity.

It can't solve all of our electric environmental needs, but it can put one h*ll of a dent in the into fixing the problem.

And have we forgot? there's hydro and wind power too.

Not that I'm a tree hugging hippie, I just don't want to see the world bathed in water and my great grandkids drowning.
Reply #744 from GalCiv2 Forums Top
And have we forgot? there's hydro and wind power too.
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hydro in the USA is almost used up. meaning that any place that can have a dam does. windmills seems to be even less efficient than solar.


and i am sorry fords wife wasn't driving a solar car she was driving an electric one.
Reply #745 from GalCiv2 Forums Top
ShadowWorrior;

Very true. I agree it'll put a nice dent in the eletrical needs of the world. Sorry, I didn't mean to sound like I was jumping all over your idea. I was kinda just playing devil's advocate and looking at what solar might be like as a global solution. Not to sound all political or anyting, but it seems to me that a lot of, shall we say "Faith", is being put into new fuel/energy sources being able to cure our energy woes, especially by the leaders (and prominent members) of our contries'.
Reply #746 from GalCiv2 Forums Top
and it seems that a lot of money is being put towards keeping energy woes and global warming from being solved. obviosly there is someone hiring all these scientists (because any REAL scientist would know better (I hope so...)) to say that there is no real problem... and who better than exxon, or a large number of gas companies who NEED the polluting gas substance to run their financial empire!

This seems very political, and (as I know you will) feel free to say something to prove the wrong in my logic!  
Reply #747 from GalCiv2 Forums Top
This seems very political, and (as I know you will) feel free to say something to prove the wrong in my logic!
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this is political. but it is the other way around. for proof that we are not doing a whole lot i give you mars and pluto.
Reply #748 from GalCiv2 Forums Top
and it seems that a lot of money is being put towards keeping energy woes and global warming from being solved
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That's because there is a lot of money at stake here. It cuts drastically on energy companies' profits to make a full blown switch to "green" energy, and this will undoubtedly get redistributed to other companies and eventually private consumers, a.k.a. US. Look at gas, for instance. We all use gas to commute, but do you realize that not only are you paying gas to run your car, you're paying gas to run the delivery trucks that drive to your supermarkets, your cities' police cars and fire engines, buses, airplanes, the list goes on and on. We spend more money than we realize on getting stuff moved around via taxes and the cost of goods at the market, and to propose just picking it all up and using new systems? That is quite a lot of money. The mere process of switching to something else will have huge repercussions throughout the world economy. Dystopic mentioned some of the problems with ethanol, and additionally it would upset the corn market at all levels, which, in America at least, is a big deal, since corn is one of the largest if not the largest crops grown here. Solar, as we touched on, just isn't that efficient. What about nuclear?, We already have enough nuclear materials to completely switch from fossil fuel industries, but to use it we would have to build nuclear plants, which are such a heavy investment that Earth might already be screwed by the time it happened. I support the idea of trying to run "green" and reduce pollution, but one thing that ticks me off is that people run around saying "the government should regulate the oil industry" or " the government should require companies to reduce emissions", but the fact of that matter is that it's not the government that is able to make this happen, it's people's money.


Hm, that was a bit of a rant, wasn't it?
Reply #749 from GalCiv2 Forums Top
nice rant. I like it.

and additionally it would upset the corn market at all levels, which, in America at least, is a big deal,
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I live in Ohio and corn happens to be our biggest crop, you can't go down any highway without seeing at least one corn feild, even though I live in the city, I would probably still feel the effect of the "All ethonal" approach.
Reply #750 from GalCiv2 Forums Top
This seems very political, and (as I know you will) feel free to say something to prove the wrong in my logic!


this is political. but it is the other way around. for proof that we are not doing a whole lot i give you mars and pluto.
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I thought we went over the mars and pluto problem on the global warming thread. (which seems to have dissappeared)