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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 #551 from GalCiv2 Forums Top
watching star trek voyager today. i realized that the occampa(i know i blew the spelling) should not exist.


why because they can only get pregnant once in their life.
Reply #552 from GalCiv2 Forums Top
since the mantle is liquid water, it must be somewhat warmer than the surface


Not necesarrily so. Water is a very interesting chemical in that solid is less dense than the liquid (ice floats). This means that you can turn Ice into water by adding pressure to it (Keeping the temperature constant - below freezing). Ice skates work on this principle. The weight of the human is transfered via a small surface area (the blade) to the ice, turning it to water. The ice skater actually skates on a small layer of water.

It very possible that the Liquid mantle is liquid due to the pressure (weight) of the solid ice above it. I guess there really isn't a way to find out untill we gather more data. Sorry to disappoint ya.

Oh yes - 68-72F is about 20-22C. Sorry, For the confusion. The rule of thum is that 1C is a little less than 2F. That and there is a 32F offset from the start of the scales
(2*20C= 40+32F =~72F (actually 68)). Its a quick way to apporximate
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Reply #553 from GalCiv2 Forums Top
Not necesarrily so...


Ah yes, I forgot about pressure. I also realized that an underwater colony would have more surface area available for heat transfer, so it would probably be more difficult to insulate in that regard as well.

In regards to your energy calculations of methane, there are significant amounts of heavier hydrocarbons (ethane, propane, and some other more complex ones), so we might be able to get better energy efficiency by using these. Additionally, on Titan, those hydrocarbons are a renewable resource. Solar radiation is continually striking the methane and converting it to these heavy hydrocarbons, but the gaseous methane is replenished by sources on the surface.

Another thing that caught my eye was the prediction that the thick atmosphere and the low gravity of Titan would allow for human flight, like we could just strap some aerodynamic boards to our arms and flap away. While our bodies aren't built for this kind of transportation, we could probably build flying installations if we wanted; perhaps our colony would be in the air?

By the way, 9/5 * C + 32 = F is the exact conversion for Celsius/Fahrenheit.
Reply #554 from GalCiv2 Forums Top
the thick atmosphere and the low gravity of Titan would allow for human flight, like we could just strap some aerodynamic boards to our arms and flap away


*googley eyes* long before sci fi ever caught my fancy i'd been obsessed with winged humans (not necessarily angels - the same visual imagery occurs in other myths, such as Nike, winged greek goddess of victory), to the point of even drawing up skematics for a set of human-propelled wings. they flapped by converting a pedeling motion generated by the arms. to the legs were tied a specially-shaped skateboard that'd double as a rear set of wings for controlling pitch, yaw, etc., and also useful for building up some takeoff momentum. an engineering friend of mine said the design skematic was great, but the human would probably exhaust him/herself trying to use it. human beings are dense compared to flying animals. true... on earth at least. i don't see anything theoretically invalid about this point - in a thick atmosphere with lower gravity, a human should be able to develop enough energy for his/her own flight - it also helps to avoid muscle atrophe!
Reply #555 from GalCiv2 Forums Top
sorry guys but our strength lies in our legs not our arms. so if we are going to fly anywhere it will have to be on a bicycle.
Reply #556 from GalCiv2 Forums Top
perhaps our colony would be in the air


Ahh ala Cloud Ctiy. I would dare say that could be very possible. Since we'd be using water to gernerate O2, We'd have tons of H2 available. Since the atmospshere doesn't have any O2, There would be a reduced fire hazard risk. Given that the difference in density from Methane to Hydrogen is greater than the different between Hydrongen and our Earth atmosphere, is would be likely that we could create a floating city. We'd have to be careful with building it (weight distrobution,etc), but with copmuters and inflatable ballasts (or is it bladders?) we could pump H2 to different areas of the colony to even it out.

The heaveir hydrocarbons don't appear produce much more Energy (I'll do the calcs later, have company over this weekend), but the alcohols of the carbons do. We could probably figure out a way to convert them to alcohols (bacteria perhaps?) and then burn them.
Reply #557 from GalCiv2 Forums Top
sorry guys but our strength lies in our legs not our arms. so if we are going to fly anywhere it will have to be on a bicycle.


this is absolutely true, at least legs vs. arms. our back and butt muscles are actually the largest and capable of developing the most mass, but the movements they're capable of aren't very easily (or comfortably) converted into other kinds of mechanical energy.

the legs vs. arms thing was something i tried to account for in my design. by no means do i think a better design using leg power isn't possible. and actually, thinking about it again, i don't think it'd be any more difficult to build and use than an arm-powered pair of "low-G wings". a laterally rigid suspension shaft could brace the legs up and allow them to pedal; as long as it could rotate along its perpendicular plane, steering could be performed by the upper body via contortion. that'd be so cool.

also, this touches on another subject with colonies in general: gravity. obviously a life on a world with much more gravity than our own could be difficult, to say the least, for anatomically current humans. special suits can accomodate higher G environments (up to 10 for fighter pilots), but i'm sure sure how productive we could be if suddenly each arm weighed a hundred pounds plus the weight of the fluid-filled suit. but i'm also thinking about life in high G. exactly how much "gravity" is too much is a separate question i'm not sure how to address. i tried googling "human anatomy high gravity" and didn't come up with much. it looks like there's not much easily available research on the subject (prolonged exposure to high G, rather than relatively short durations). i suspect that without genetic mutation, we'd have to live in stations in low orbit, and "commute" to the surface for work in special suits.

low G is another issue entirely. muscles tend to atrophe without word; astronauts on long missions have to exercise or face dangerous conditions when they return to constant life in full G (incidentally, meaning they need more oxygen and more food to stay healthy). on lower G planets, i think there would be some leeway in this. as long as you, say, couldn't just jump out of the gravity well, new types of exercise would be possible - new takes on old sports and entirely new sports (such as self-propelled flight).


i'm going to tangent for a second about writing, but in a way that's related to the above. one key to writing is living. doing stuff. and the more stuff you do, the better you can write. it's certainly a craft unto itself, writing, but it's one that deals in the most operatively flexible medium of expression: verbal language.

and that's why they say, write what you know. i've a wide variety of hobbies and experiences, including several athletic/kinesthetic. in high scool i was on the (american) foodball team (D tackle), wrestled and threw in track and field, i was in the swing dance club, i skateboard and surf (well, i try anyway, i don't get out enough to really say surf well), and i'm about to take up tai chi with a friend from work (including learning several traditional chinese weapons  ). so while i'm still undecided on Titan as prime real estate for a story, a low G world would definately be a cool place to write about.

i've been getting a lot of great ideas, especially for setting, from this forum. writing fiction takes a bit more time, it takes ideas of different sorts coming together. i've got scraps of conversation and scenery for the first story. a notebook of random ideas, images, observations, etc., that i carry around with me a lot of the time. it's great material for both detailed description generally and especially characterization. but i do have a full-time job, so this isn't going to happen at an especially rapid pace. but in a few months i think i might have a draft of the first story. i have a two week vacation in the end of december, so that'll be a nice chunk of time to work on this (my family doesn't really do much for the holidays).
Reply #558 from GalCiv2 Forums Top
perhaps our colony would be in the air
Ahh ala Cloud Ctiy.


why not just use some variety of a space elevator and sit in low orbit?

though, denyasis, i think your idea might benefit from easier expandability. maybe the easiest method would be the same general idea used in modern skyscrapers - allow different sections of the colony to move a bit. if one became suddenly too heavy, it wouldn't be as cruicial to pump H2 around everywhere in split seconds. more minute adjustments could just be made with super-fans and local motion sensors (too much tipping in the right direction = fan adjusts greater or lesser stregnth accordingly). then a central ballon-type thing would provide the main lift force.
Reply #559 from GalCiv2 Forums Top
Mind bringing me up to speed? I'd like to get in the discussion but I don't think I would want to sift throught all 12 pages.
Reply #560 from GalCiv2 Forums Top
low G is another issue entirely. muscles tend to atrophe without word; astronauts on long missions have to exercise or face dangerous conditions when they return to constant life in full G


But there would be no return from an extra solar colony would there? Perhaps this would be a good thing in a story: new colonists have to adapt to a change in gravity, and extrapolating this simple change in their lives out a hundred years or so this leads their entire society to something very different from Earth's culture. They might even look different: low gravity allows for taller people. Eventually these humans might consider 7 or 8 feet tall the average.

---------

Mind bringing me up to speed?


At the moment we are discussing possible colonial life on a Titan-like planet (wiki "Titan"); look at response #536 for a general idea of Titan and the posts after to see what sort of ideas have come up about it. Then, comment on ideas, or bring your own to the table.

Welcome, FireBender.
Reply #561 from GalCiv2 Forums Top
They might even look different: low gravity allows for taller people. Eventually these humans might consider 7 or 8 feet tall the average.


The same(only other way around) could be said for heavy gravity.

new colonists have to adapt to a change in gravity, and extrapolating this simple change in their lives out a hundred years or so this leads their entire society to something very different from Earth's culture.


Actually, you don't need a different planet for a revamp of society in a 100 years. Take a look at the societies of the world a hundred years ago. I believe you would find enormous differences.

Even if you put two groups of people from the same time period in separate identical(or different) locations and leave them be for a hundred years or so completely isolated from the other. At the end you will discover very diverse societies. Not of the same people that were originally used for the test but their future generations.


-Fire

Reply #562 from GalCiv2 Forums Top
the Fahrenheit temperature scale is more useful to the average citizen because smaller denominations translates to higher accuracy.


That makes sense. I have to admit some hostility towards the fahrenheit and imperial systems because of all the times it has prevented information presented in American shows from being understood by me! It gets a bit frustrating.

Also in my job, when i recieve reports on our companies stock imported from India, sometimes i get the occasional measurements reported in imperial! mixed in with metric!! That usually stops me dead in my tracks in the office (imperial measurements do not convert neatly into metric) and i wish they would just put these old systems to death once and for all and be done with it.
Reply #563 from GalCiv2 Forums Top
it looks like there's not much easily available research on the subject (prolonged exposure to high G, rather than relatively short durations).


I think you kinda generally answered you own question here:
low G is another issue entirely. muscles tend to atrophe without word; astronauts on long missions have to exercise or face dangerous conditions when they return to constant life in full G


Going from Earth (1G) to a higher G planet is akin from going from orbit (0G) to 1g. The same dangers are present. Part of the reason why there is not much research on this topic is that it is very dangerous to experiment on. The Stress of High G is certianly deadly after extended periods of time (I'd bet a paycheck on Heart, Liver, and Kidney failure). I would imagine that less hardy individuals (infants, children, elderly) wouldn't be able to survive at all.

A low orbit solution would work. In fact, Why go down to the surface at all? With modern robotics, it could be totally possible to to do work (mining, exploring, arigriculture) via remote controlled robots

why not just use some variety of a space elevator and sit in low orbit?


My understanding is that would require a continual energy source, right? Using the balloon analogy wouldn't, just fill em up. I figure it could work like the Ballast Tanks in submarines (atleast mechanically). I like the use of fans (I would assume that Jets wouldn't work - no oxygen, but if we used electrolysis to generated H2 and O2, and then burned them back to water, we could make a jet engine/rocket with more force - viola idea!) for more minor corections (especially against drift from wind - could we anchor it to the ground?)

Actually, you don't need a different planet for a revamp of society in a 100 years


This is true. Part of our earlier discussion was what types of people might sign up for a colony and what type of culture would that lead to. Granted that its a very open and ambiguous question but we were looking at what type of conditions would Future Earthlings be living under to make tham want to colonize and how would the fundamentals of colony life change (if at all) the basics of the society. Hope that helps bring you up to speed.
Reply #564 from GalCiv2 Forums Top
Going from Earth (1G) to a higher G planet is akin from going from orbit (0G) to 1g. The same dangers are present. Part of the reason why there is not much research on this topic is that it is very dangerous to experiment on. The Stress of High G is certianly deadly after extended periods of time (I'd bet a paycheck on Heart, Liver, and Kidney failure). I would imagine that less hardy individuals (infants, children, elderly) wouldn't be able to survive at all.



this would just be climate assimilating. on the other hand your heart would have to work harder. i think it would just shorten the first gens life span. children born there would be use to the g's and have no problem.

now if we are talking about 5 g's yes a lot of people wouldn't survive for long. but again any children born there would.
Reply #565 from GalCiv2 Forums Top
could we anchor it to the ground?)


with an elevator shaft or two
Reply #566 from GalCiv2 Forums Top
now if we are talking about 5 g's yes a lot of people wouldn't survive for long. but again any children born there would.


this would mean that the first gen would have to get pregnant in space and then land. the children would have to grow up there not just be born.
Reply #567 from GalCiv2 Forums Top
children born there would be use to the g's and have no problem.


There would be significant limitations to the immediate adaptability of the human race to high gravity. You would have to ensure all those individuals who were best addapted are the only ones to have children so that over many generations humans would become genetically suited to that environment.
Reply #568 from GalCiv2 Forums Top
You would have to ensure all those individuals who were best addapted are the only ones to have children so that over many generations humans would become genetically suited to that environment.



why they may not be adapted but their children may be.
Reply #569 from GalCiv2 Forums Top
why they may not be adapted but their children may be.


well their children probably would be better adapted but that would be environmental adaptation not genetic adaptation. Environmental adaptation is along the lines of how mountain climbers will camp out for several months at high altitude to adapt to the thin air before attempting the final climb. Any children borne at high altitude will likely be even more well adapted to thin air than those climbers could ever achieve.

However some individuals will be slightly better suited to the thin air than others, this is due to genetic variation. If only those individuals with slightly better adaption to thin air are allowed to have children and then the process is repeated for those children and so on and so forth through the generations, you will begin to see genuine genetic adaptation to breathing thin air.
Reply #570 from GalCiv2 Forums Top
ok how many brains produce athletes

and how many athletes produce brains.


your first impersion of me would be an athlete.


before you talked to me.
Reply #571 from GalCiv2 Forums Top
ok how many brains produce athletes

and how many athletes produce brains.


your first impersion of me would be an athlete.


before you talked to me.


facts remain what they are regardless of impressions.
Reply #572 from GalCiv2 Forums Top
all i am trying to say is that genetics take several generations to change.

it takes threee generations to make a wolf a dog.
Reply #573 from GalCiv2 Forums Top
all i am trying to say is that genetics take several generations to change.


It depends entirely on what you have to work with in the beginning. Very small genetic variations would take a very long time to develop into a full blown characteristic.

You cannot make a dog out of a wolf in 3 generations if you only have wolfs to begin with.
Reply #574 from GalCiv2 Forums Top
You cannot make a dog out of a wolf in 3 generations if you only have wolfs to begin with.


a wolf becomes a dog when it's coat starts to become colorful.


you make a wolf into a dog by breeding for less aggression. it only takes three generations for the coats to start changing.


i saw this on the discovery channel. i think it was discovery might have been animal channel.
Reply #575 from GalCiv2 Forums Top
you make a wolf into a dog by breeding for less aggression. it only takes three generations for the coats to start changing.


ah ic, yes if you broarded your definition of the term 'dog' enough then that will get you there.