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!
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Reply #751 from GalCiv2 Forums Top
come on you don't really believe mars and pluto are warming up only because the earth is.


there has to be a common reason and that reason is the sun not man.


not saying that we aren't having an impact just not as big as they say we are.
Reply #752 from GalCiv2 Forums Top
okay the most recent post is on a new page, so forgive me if i don't back track merely to quote. the threads taking on some political qualities, but i don't think there's a problem with that, as long as remember it's a discussion we're having, not a struggle over the future, and remain respectful of one another.

on sustainable energy: i believe no source of energy we have now would meet the world's energy requirements if we cut out fossil fuels and continued living the way we do (in the developed world). i believe Millertime described the various transportation social systems that also rely on fossil fuels pretty comprehensively. if we ever develop efficient fusion power, i think that will clearly be the best choice. however, one thing to bear in mind in these regards is that a technology's efficiency is partly a product of the physical conditions the technology is based on (how energy is converted to a form we use, usually electricity), but the other part of efficiency is based on how much development we invest into the technology. while it's true that photo-electric cell technology has a lot invested into it, it's nothing compared to the R&D budgets of the big fossil fuel companies. if, say, fossil fuels were to become too expensive to be practical for most things, i could envision a major shift in our research priorities becoming much more likely.

i'm not a huge fan of fission nuclear* power, but it's better than fossil fuels. hydro power distrupts natural environments, and as danielost pointed out, most of the more efficient locations for hydro power are taken in north america (save for tidal generators, but coastal zones are some of the most sensitive natural environments there are).

there are lots of problems, and i don't see any immediate solutions that'll simply fix everything. beyond developing a new source of power, the most important thing we can do is change our lifestyles. buy locally grown food supports local farmers, who usually use more environmentall friendly growing methods, and it also saves the cost of transporting your fuels. switching to compact florescent bulbs, limiting your home's heating and cooling, etc - changing our lifestyles has to be a big part of solving the world's energy problems.

again, i'm not being preachy here. this actually plays into the thought i have about my books. people in the future are going to live in an abundance of technology but a scarcity of natural resources, mostly coming down to power. coping with a changing environment (to whatever extent it's caused by our own activities or is happening on its own) will also be a significant experience in our near future - one which i think could help us prepare for coping with life on other planets. in other words, as the earth changes, we'll have the opportunity to learn what we need to live on a planet that isn't perfectly suited for us.

and don't mis-read me: i care very much about the political sides of these topics we've been touching on - i'm just trying not to get too distracted.

*on a somewhat related note, i've been reading Asimov's Foundation trilogy, in which "nuclear" technology plays a major role of the science side of his fiction: i find it kind of whimsical, in a sense. in a way, 'nuclear' is a dues ex machina in his stories; technology involving the manipulation of matter on subatomic (i.e., nuclear) levels is everywhere, but there's almost no descriptions of how it's achieved. i don't mean that as a criticism; much less was known about subatomic phenomena when Asismov was writing; it's just that it gives me a nostalgic, fuzzy feeling when i think about how much has human beings have learned (in some very specific areas) in such a short amount of time.
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Reply #753 from GalCiv2 Forums Top
on a somewhat related note, i've been reading Asimov's Foundation trilogy, in which "nuclear" technology plays a major role of the science side of his fiction


Personally, although some of his references we're clearly dated (miniature nuclear devices), I thought Asimov did a wonderful job creating a "plausible" future without getting bogged down in Scientific or technical details. He keeps the story upfront and center which I think is the great strength of his trilogy. The thing that gets me about some scifi books and stories is that they read too much like a tech manual.

I really do enjoy how a lot of the technology is vaguely described, as it lets the reader imagine the story the way they want to, instead of fighting the readers imagination and it demonstrates how much technology can advance, but how little the common person will realize it or understand how all the advancements of the future work. Take for example our technology. There's a lot of technology that we take for granted and haven't a clue how it exactly works.

Ender's Game had a similar approach. just enough Technical explanation was used to facilitate the story, but not soo much that it bogged down the narritive its self.
Reply #754 from GalCiv2 Forums Top
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.


Well you use the fuel atoms of course, thats why it is called 'fuel'.

I wonder what effects an increase in mass would have on fission or fusion or chemical reactions? Perhaps it would slow things down? That would be kinda like a time dilation effect?

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.


In a sense yes, but the energy gained would only apply to directional changes, not velocity. As far as i know, a ship with little mass will gain the same acceleration benefit from a slingshot as a ship with a large mass.

If however the ship is going so fast that it's mass is astronomical, then a slingshot manouvre would have little effect on the ship and probably drag the hapless planet off its orbit! (Or have no effect at all because it was simply moving too fast). Anything that can shift a planet in such a way would require an astronomical amount of energy to gain such speed in the first place!!

Reply #755 from GalCiv2 Forums Top
Well you use the fuel atoms of course, thats why it is called 'fuel'.


But that would be redundant. Carrying extra "fuel" atoms would only slow the ship down, because of the extra mass that needs to be accelerated, countering any increase in thrust applied.
Reply #756 from GalCiv2 Forums Top
But that would be redundant. Carrying extra "fuel" atoms would only slow the ship down, because of the extra mass that needs to be accelerated, countering any increase in thrust applied.


Yes true... well i think that is the basic reasoning for why traveling at the speed of light is impossible.

What i am suggesting is a way of somehow forcing energy output to increase exponentially along with the increasing mass if that were possible? Or to somehow counteract the effects of increasing mass? Either way the first step would be to hypothosise the effects of great speed and increasing mass on such things as fusion or fission reactions?
Reply #757 from GalCiv2 Forums Top
what if the light barrier is like the sound barrier.


you cant brake the sound barrier without lots of energy or a special design because there is a shock wave building up in front of it.

what if the light barrier is just a wave in front of the ship and once you breach it all of that extra mass just goes away. of course the only way to test this is to go faster than light.
Reply #758 from GalCiv2 Forums Top
what if the light barrier is like the sound barrier.


Well i guess the key difference would be that they had reasonably sound physics providing grounds to develop appropriate machinery to set about breaking the sound barrier.

We do not yet have any physics that are extensive enough to give us some idea of what machinery we could develop in order to set about breaking the light barrier?
Reply #759 from GalCiv2 Forums Top
We do not yet have any physics that are extensive enough to give us some idea of what machinery we could develop in order to set about breaking the light barrier?




before you can purposely brake the wave you have to be able to see or detect it. as i said before the french under neopolian were the first ones to run into the sound barrier. it wasn't until the bullets that we have today did we brake the sound barrier by accident. for america this was during the civil war
Reply #760 from GalCiv2 Forums Top
on going faster than light:

einstein's theories postulate that it'd be impossible for your two accelerate to or above the speed c, the speed light travels in a vacuum. as explianed previously, as you approach the speed of light your mass actually increases and approaches infinity as you approach c. you can't 'use' the extra mass by converting it to energy. as i understand it, the extra mass actually comes from energy (the energy it takes to travel that fast). therefore, burning fuel in any way wouldn't release any more energy than it would at rest; the only "extra" energy it's gained as a result of being accelerated is represented in its current velocity. something of the ship needs to survive as a ship or the acceleration is meaningless, but if it were to reach speed c, it would have infinite mass: the acceleration to get there would either take infinite time or infinite acceleration, but in either case, infinite energy. going over the speed of light would therefore take more than infinite energy, which is obviously nonsensical.

now, einsteins theory doesn't exclude things that always travel at the speed of light or above it. it also doesn't exclude something that's usually sublight from going faster than light; it only exclude acceleration to and above light speed. the geometry of any FTL phenomenon would therefore have to be non-continuous, like a tangent curve.

unfortunately, continuity is a problem with ideas like 'warp' - i.e., travelling through our 3+1 dimensional spacetime in a straight line, at FTL by warping space. you can't control a warp bubble from inside it, and additionall you can't move through its edges safely.

unfortunately there's nothing in known physics, nothing i know of anything, closely resembling 'subspace' or 'hyperspace' - no extra dimension we can slip through to get places faster.

that leaves wormholes, which also haven't been completely discounted. but they present a challenge to pragmatism. the only thing we know of that bends space in anyway like a wormhole is a black hole, so you can see we're not talking about trivial amounts of force here. the first thing we'd need to do is understand gravitons a little better, assuming they exist. if they do, they're what communicates the gravitational force, and what we'd need to harness to bend space.

stargate, while cheesy in a good way as often as not, is actually a clever show a lot of the times. if you look at the way the stargate is described throughout the show, it's actually half transporter (a la star trek) and have wormhole. the matter is deconstructed into energy and reassembled on the other side.

in a way, this makes sense. if you were going to make a wormhole practical for interplanetary use, it'd have to be nanoscopic: only big enough to send an information/energy beam, otherwise the gravitational distortions near the wormhole would to far too disruptive for it to be useful. of course thise explicitly goes against the canon of the show at many other times, but that's how i think it'd work, if at all.
Reply #761 from GalCiv2 Forums Top
you can't go faster than light, in theory.

light is made of photons, which aren't actual solid particals, and contain next to no mass, so they can go as fast as they want, without much mass increase...
Reply #762 from GalCiv2 Forums Top
einstein's theories postulate that it'd be impossible for your two accelerate to or above the speed c, the speed light travels in a vacuum. as explianed previously, as you approach the speed of light your mass actually increases and approaches infinity as you approach c.


But what is the actual reason for the increase in mass? Is it like time overlapping on itself, is that what is causing the mass increase?

One thing to consider about the theory of relativety is that word 'relative'.

I could imagine that a spaceship moving at the speed of light, from its perspective, it would not be increasing in mass at all, but the rest of the universe would appear to be decreasing in mass?
Reply #763 from GalCiv2 Forums Top
E=MC2 and i can't do the little two thing. But what it is saying is that mass is energ and energy is mass. To have speed you must have kintec engery so as soon as you hit light speed you are infinty large and are on all pionts in time. and no the rest of the universe would not seem to be decreasing in mass. I'm in favor of bending space not in have giant thrusters to power a starship.

Any heard of Dovin Basils off of star wars the creatures that use gravity as move in space and as sheilding?
Reply #764 from GalCiv2 Forums Top
you know what the problem with the theory of relatively. it breaks down at the speed of light. which is why it is still a theory.
Reply #765 from GalCiv2 Forums Top
But what is the actual reason for the increase in mass? Is it like time overlapping on itself, is that what is causing the mass increase?

One thing to consider about the theory of relativety is that word 'relative'.

I could imagine that a spaceship moving at the speed of light, from its perspective, it would not be increasing in mass at all, but the rest of the universe would appear to be decreasing in mass?


well no (edit: that should be a "yes" - i mis-read your post), from the ship's own perspective its mass wouldn't change, but to the rest of the universe, it would be increasing. alternatively, the mass of the rest of the universe would seem to be decreasing from the ship's perspective.

you know what the problem with the theory of relatively. it breaks down at the speed of light. which is why it is still a theory.


what do you mean by that? in what way does it 'break down'?
Reply #766 from GalCiv2 Forums Top
But what it is saying is that mass is energ and energy is mass.


Therefor if mass is energy, it can be harnessed? The power of mass used against itself to cancel out the problem of increasing mass?

To have speed you must have kintec engery so as soon as you hit light speed you are infinty large and are on all pionts in time.


Kinetic energy in itself is not energy at all. it relies on the relative velocity of other matter in the universe to be worth anything. Light is not infinately large and on all points of time, you are thinking of nill time existance which is somthing entirely different, and another possible way of traversing the universe instantaniously!

well no, from the ship's own perspective its mass wouldn't change, but to the rest of the universe, it would be increasing. alternatively, the mass of the rest of the universe would seem to be decreasing from the ship's perspective.


Huh? you start with 'well no' and then repeat what i said?
Reply #767 from GalCiv2 Forums Top
what do you mean by that? in what way does it 'break down'?


1 the speed of light isn't constant. yes i have said that before.

2 according to Einstein anything that goes the speed of light becomes energy. and the speed of light remains the same speed no matter how fast you go.
Reply #768 from GalCiv2 Forums Top
Huh? you start with 'well no' and then repeat what i said?


that was a mistake, which i managed to edit before you posted that  

1 the speed of light isn't constant. yes i have said that before.


this is true. but speed c is constant, which is the speed of light in a vacuum.

according to Einstein anything that goes the speed of light becomes energy


actually, according to Einstein anything that goes the speed of light is already massless, since nothing can accelerate to the speed of light. in other words, the only things that go the speed of light must always go the speed of light and must also be massless or nearly massless.

relativity is still a thoery, but these aren't the reasons why it's still considered a theory AFAIK. i believe it's because large parts of Einstein's predictions are still un-testable.
Reply #769 from GalCiv2 Forums Top
maybe... eintsien... was... wrong?   XD
Reply #770 from GalCiv2 Forums Top
I have heard of Dovinal basins. They project small black holes around the ship they are on, which then shields the ship. Or they some how make acceleration to move the ship. Of course, they are organic so they tire out after a brief time.

question, I thought that scientists have "seen" into the 7th demension by creating small black holes by hitting gold atoms against each other. (or so I have been told)
Reply #771 from GalCiv2 Forums Top
this is true. but speed c is constant, which is the speed of light in a vacuum.



in a vacuum on earth
Reply #772 from GalCiv2 Forums Top
this is true. but speed c is constant, which is the speed of light in a vacuum.



in a vacuum on earth


all vacuums are the same (except the ones you buy at a store).
Reply #773 from GalCiv2 Forums Top
I have heard of Dovinal basins.


i haven't, and i wasn't able to find anything about these using google. are you sure you spelled correctly?
Reply #774 from GalCiv2 Forums Top
this is true. but speed c is constant, which is the speed of light in a vacuum.



in a vacuum on earth




space isn't a vacuum
Reply #775 from GalCiv2 Forums Top
space isn't a vacuum


okay, the quantum take on the speed of light.

the speed of light is constant. whenever is a photon moves through empty space, it moves at speed c.

however, space isn't empty. well, except on very small scales between molecules. so as a result, light 'slows down.' except it doesn't travel more slowly, it travels less frequently. photons are absorbed into electrons and shortly re-emitted. over a long enough distance (on the order of milimeters) this absorbtion/emission causes the average speed of light to decrease. the amount it decreases is a result of how dense the substance it's moving through is, and that amount is referred to as the refraction index. the 8 million year delay on photons making it from the center of the sun to its surface is caused by the same phenomenon.

therefore, light, when it's light, always travels at the speed of light. but light doesn't always travel, sometimes it's existing as an electron in a higher energy state, and to us 'big' things, it would seem like the speed of light is slowing down.

einstein didn't have the mental tools to describe this; this is coming from quantum chromodynamics.