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Interstellar Ark
xantox writes "There are three strategies to travel 10.5 light-years from Earth to Epsilon Eridani and bring humanity into a new stellar system : 1) Wait for future discovery of Star Trek physics and go there almost instantaneously, 2) Build a relativistic rocket powered by antimatter and go there in 22 years by accelerating constantly at 1g, provided that you master stellar amounts of energy (so, nothing realistic until now), but what about 3): go there by classical means, by building a gigantic Ark of several miles in radius, propulsed by nuclear fusion and featuring artificial gravity, oceans and cities, for a travel of seven centuries — where many generations of men and women would live ? This new speculation uses some actual physics and math to figure out how far are our fantasies of space travel from their actual implementation."
I would just take billions of pill sized coctails of bacteria from all extreme regions of the earth and fire them off semi randomly throughout the galaxy, wait a billion years for them to evolve and contact us back.
Mouse powered Chips, Open source Processors and Lego
we could do that, but the odds of us being screwed over by either a gamma ray burst or some other dangerous interstellar space event would be pretty high.
but then again, the resulting mutations might come in handy.
Viable Slashdot alternatives: https://pipedot.org/ and http://soylentnews.org/
So, let's take a passenger manifest...
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How many human societies have survived 7 centuries unchanged?
Heck, just look at how much language has changed in the last century ...
Or imagine trying to talk to someone from the 1300s ...
Besides, how would you select the crew and avoid any more "diaper rash" candidates?
I don't mean to be existential about this but why? We don't have a mission from God to spread and conquer. It seems a little strange how atheists are very keen to strike down the pointless values of religion, yet still believe in many aspects which have no basis.
What's the goal here? After billions of years the human race is all over the galaxy, few billion years later and its all over the universe. And then what? We cling on for dear life as we exploit the last few sources of energy as black holes swallow up any traces of our fantastic achievements.
Mouse powered Chips, Open source Processors and Lego
* Decode and activate appropriate chevrons on that Stargate-thingy.
VOTE!
.....might be to determine if Epsilon Eridani has any terrestrial planets to live upon. Boy would our ancestors 700 years from now be upset if they got there only to find no place to land.
adventure-today.com
How would you ever get that many people to cooperate that consistently over that long of a time period? How would you prevent the intermediate generations from feeling like they are meaningless just because they only exist to father the generations that will be able to accomplish something? The rate of clinical depression caused by that would be probably staggering. How do you prevent the development of new religions or philosophies or conspiracy theories that would hinder the progress of the voyage, or perhaps express doubts its goals? Not to mention the more mundane problems like new bacteria and viruses mutating on the tiny ecosystem and wiping out all of its occupants, and liberationists starting political revolutions (ala: we didn't choose this voyage, why should we finish it?), and psychopathic serial killers, and the question of how such a tiny economy would maintain itself (do we go communist or capitalist on this voyage)?
...En að Besta Sem Guð Hefur Skapað Er Nýr Dagur
They will all be really bummed out when during their journey of centuries, somebody invents #1 and gets there ahead of them.
For an interesting read on what such a ship might be like, take a look at: Rendevous with Rama by Arthur C. Clarke. I read it not long after it came out and thoroughly enjoyed it. Highly acclaimed, too:
it seems like it would actually be 1400 years as he's presumed constant 1G acceleration towards the destination for the whole trip. Once you got there you'd need to go into a decreasing orbit and slow down for about 700 years (assuming 1G) too!
It seems to me that there is a 4th solution, assuming that it is possible to build a computer powerful enough to simulate a human mind, and that it is possible to upload a human consciousness into such a structure. Sending a machine across interstellar distances is likely going to be significantly more practical than trying to transport billions of tonnes of habitat. You don't have to worry about setting up complex biospheres; all you need is a computer significantly robust to survive in interstellar space, and we have more experience in this field than in self-supporting biospheres.
Likewise, it doesn't seem like it'll be too many decades before we have the technology construct a computer powerful enough to simulate (to a reasonable degree of accuracy) the trillions of parallel interactions that occur every second in our brains. Figuring out a way of mapping neurons to 1s and 0s is likely to be a far more difficult problem, but it seems to me that this would be a relatively simple problem compared to creating some manner of ark-ship. Research into this is likely to be relatively inexpensive by comparison as well, as we could start by mapping brain structures of simpler animals (such as Lobsters), and then work our way up.
I suspect that when humanity does visit the stars, it'll be as lumps of silicon (or some more exotic material) strapped onto a dirty great big rocket. Ships that lug their own biosphere around with them are just too costly and complex by comparison.
Well, Rendezvous with Rama itself didn't explore the idea of human beings en route across the galaxy, since Rama was then just a mysterious alien object that dipped into our solar system, got explored a bit, and then departed. It was only those atrocious sequels penned by Gentry Lee that had humans staying on it and riding it out to far away places. Apparently the only thing Lee found worth exploring in the concept was puerile sex scenes and soap-opera intrigues, and lots of 'em.
I'd recommend instead Gene Wolfe's Book of the Long Sun which, even if the technology is a bit out there, is a much more likely scenario from a sociological point of view. If you're looking at a journey of hundreds of years in a ship big enough to seem like an expansive world and not just cramped quarters, there's going to be people dividing into factions based on disagreements, there will probably arise a class difference between those who do the steering and those who are just "cargo", and there will be people at the end of the voyage who will not want to disembark from home onto a potentially unpleasant colony world.
Why not all three?
Start out with the generational ship. Resupply them with constant acceleration anti-matter probes.
Then we'll pick everyone up in a few hundred years and carry them the rest of the way with warp drive.
Instead of building one large ark and setting up for one large catastrophic failure, build lots of smaller arks that can fly in formation. If one runs into an asteroid or breaks down, the rest will be OK. It may even be possible to allow for transportation between the different arks.
m0nstr42.blogspot.com
If you have the tech and money to build something like an O'Neill structure, you don't need to leave the solar system for thousands of years...
The article states "The only theoretical limit is the acceleration, which should be kept within physiologically acceptable limits for a human, that is to 1 g or 9,81 m/s", which is not quite true. Jet fighter pilots have to take up to nine G during dog-fights (more than nine G leads to black outs), which is one of the reasons why on the long run the jet fighter pilot will become obsolete, since UAV's can handle more. The nine G figure is unrealistically high, but there are no reasons to assume you can't have a realitivistic rocket that starts out with six G for a short while and then drops its acceleration off to about two G. Combine this with some form of suspended animation, which we can already do for mice and all of a sudden the relativistic rocket becomes less far out.
-- Spelling and grammar errors tend to be a sign of erroneous thinking.
Not really sure why you posted as AC as you have a good point. Though as some one who's been rather interested in history (Greek through to now) I've noticed a very strong trend in over coming goals. Lets assume that since boats were 'invented', lets say x years ago where x is when the native Australians might have done it - 30,000 years - or the more common understood starting point - 15,000-8,000 years - as our time frame, we will call that the start of non-normal travel (normal being by foot) - I would like to avoid over land travel as I doubt we can even guess when the first person rode a horse.
Anyway under that assumption lets really view the time frame. The last 30000 years have been boring on the sea if you were in a boat with only limited jumps forward until 4000 years ago when the jumps really started to pile on top of each other and suddenly boats really started moving forward. Overland travel saw this event over the last 300 years from horse back to maglev trains. Powered planes didn't even exist at the start of last century and within a century of existing they have already reached scramjet abilities (some thing books I've read from the sixties joked about as never happening in their life time or even ever). Which leaves us with space flight...From the Germans flinging rocks around in WW2 to landing rovers on Mars and exploring it in well under a century. The advances have been insane so really as long as there are advantages to the general population and adventures like this don't detract from needing issues I believe the question becomes why not?
As for the time scape between now and when black holes wipe out everything it isn't worth thinking about. Many generations will have hopefully had a bit more fun while living as a result of exploring everything...Heck there may even be life out there that gives the question to the great answer.
I ate your fish.
Travel over a period of 700 years with 1000 or so people introduces a massive risk in that we have no way to assure that the culture of such a small population in isolation could survive. If they did survive, how much has society changed in the past 700 years? With only one ship, all our eggs are in one basket, so to speak. Instead, it makes more sense to send small ships laden with thousands of freeze-dried gametes, thaw them out, and nurture the embryos to maturity.
The ship would leave with the sperm and eggs of many carefully selected individuals suitably freeze dried. The small ship would require much less energy and the cold of interstellar space would keep the embryos nicely preserved. Upon locating a suitable planet, the onboard intelligence would thaw and combine the gametes and voila - people. Managed by the computer and residing on the planet, the population would grow and by adolesence start to multiply. The accumulated knowlege of humanity would accompany them and they would use it as a means to get themselves started.
In fact, since the cargo is light, a mother ship could release one of 100 individual 1000 embryo capsules while passing apparently suitable worlds and continue on to others. That way, the survival of at least a few groups would be more likely.
Of course, the people already on the planet might not like the goings-on but that would be a problem in any case. The humans might populate their zoos, become slaves, become worshiped, or maybe we don't drop people on planets with really intelligent life. Humans seem to like to be at the top of their local pyramid. It is up to our sci-fi writers to explore and filter the possibilities and guide the implementaiton.
If each colony carries the information to construct and launch a ship, the universe would be ours rather quickly, even if only 10% of each generation of colonies survived.
One other advantage to this plan. The people would know whence they came, how they got there, and what their destiny was. Mystics and Philosophers would not be required in that gene pool. Of course, they might wonder where WE came from, but that is another problem.
Humans are incredibly fragile (both physically and psychologically), live short lives, and space is immense and utterly hostile.
Years ago I worked through a lot of numbers for fusion ramjets, antimatter, laser-powered sails et al.
The only interstellar travel I can see us ever doing is as frozen embryos.
Generation ships would be bloated tombs. There would be a serious shortage of funding and volunteers. People won't consign themselves to die without reaching a destination, after years spent inhaling each other's BO.
Self-reproducing intelligent robots, OTOH, could crawl along between the stars at 1% c happily. 1,000 years of travel is nothing to something that can turn itself off and then back on.We could travel with them, in the aformentioned frozen embryo form, to be gestated in artifical wombs on arrival.
Interstellar ships will never be built by humans. No return on investment and no glory in a lifetime = no deal. Self-reproducing robots are the way to go.
Azural - instrumentals
.. and now I'll reply to my own post with more information.
Per this nice page:
The idea of a multi-generational ship or "interstellar ark" is an old one that was proposed in an unpublished paper by Robert Goddard in 1918. Goddard's fellow rocket pioneers Konstantin Tsiolkovsky and J. D. Bernal also considered the idea in the 1920s. Olaf Stapledon and Don Wilcox wrote stories about the idea in the 1940s, and Robert Heinlein originated the notion that inhabitants might forget they were on a ship in his book Orphans of the Sky. Nevertheless, considering the energy, ecology, and life support needs such a ship would require, the interstellar ark is a highly unlikely prospect.
Don Head
UNIX/Linux Administrator
Without some means of sending a probe will in advance of our colonization efforts we could find a system full of gas giants like Jupiter, Saturn, Uranus, and Neptune, dessicated balls of rock like Mars, acidic pressure cookers like Venus or sterilized, blasted hot rocks like Mercury. Moving any body at near-relativistic velocities means that it won't turn worth a damn. Once you have completed most of your acceleration on the way to the target system you are pretty much committed to that destination. If it ends up being without planets friendly to our form of biological life you may end up with a space based colony, eking out it's existence among the asteroids or small moons of that system. This is not a viable, long term colony unless we have a mastery of living in space and in low gravity environments. Before we send colonists on what is essentially a one way trip, we should try to establish a few long term, self supporting colonies in our asteroid belt. This would be an ideal place to perfect the colonization efforts that may greet our colonists in another system.
Tisha Hayes
Instead of building this huge arc and going there using fusion power (fusion reactors are not small or lightweight), you would build a large space based mass driver (nanotechnology cares significantly less about high-g accelerations than human bodies) and launch a carrier at 0.1c or 0.5c (increasing v if you are willing to expend the energy, decreasing v depending upon the mass required for shields to defend against damage caused by encountering interstellar dust at high velocities). The carrier contains either its own mass driver or moderately large chemical rockets that launch the probe in the opposite direction at -0.9999... * v of the carrier entering the system so as to result in the probe having a net velocity that will result in its capture by the gravity of the destination system. The first probe can then go about constructing an reverse mass driver so future probes can be decelerated using power from the destination system (allowing most of the subsequent mass transfered to be "information content" rather than power systems or velocity control systems [2]).
If most of humanity hasn't undergone mind uploading several hundred years from now I'd be very surprised. So those early pioneers who decided on the "ark" approach are going to very surprised as they approach the destination system and discover that it has been converted into a Matrioshka Brain [3] and there is nothing left to explore or colonize [4,5].
No matter *how* pessimistic you are about molecular nanotechology developing in the next two decades -- you have to make a *very* strong argument that it will not be developed over the next fifty years [6]. So any future planning scenarios involving 100+ year time frames should be left as virtual reality exercises.
In order for us to actually do something like this, we'd have to get past all the dogma involved in the creation and taking of human lives. Since you are dealing with severely limited resources within a highly confined area, we would need to regularly sheer our numbers down, "Logan's Run" style. Anyone on this ark would have to agree to be put to death once they've become unable to contribute into the community by as much as they take away from it. This means all severely disabled, physically/mentally handicapped, or just plain lazy people would have to be destroyed and recycled back into the community ecosystem, regardless of their age or status among the community itself. It would be the ultimate in "zero-tolerance" policy, with sentencing issued and carried out with extreme prejudice. It would require death squads equal to the Nazis during WWII... only done out of necessity, rather than hatred. (Every second a useless individual mooches off the community, the less resources the contributing members of the community have to survive on.)
The concept of family would be a thing of the past, replaced with child farming. There would be no relationships between anyone outside of basic affection. Sex itself would be discouraged or considered a capital offense, as the act itself would waste precious resources. Instead all children would be a product of test-tube fertilization. Every member of the community would be required to submit their egg/sperm cells every few weeks to be catalogued in order to keep the gene pool as diverse as possible. After fertilization, the embryo is placed into one of several hundred women tagged as surrogate mother stock, who's sole purpose in the community is to be impregnated, gestate and give birth, not unlike a queen insect laying thousands of eggs... while the real mothers of these children are left to continue work in whatever section of the community they serve in.
These child farms then serve as large scale permanant daycare centers until the children are old enough to contribute back into the community. No child would ever know their real parents or genetic siblings to prevent familial conflicts from disrupting community contribution. Names would be assigned only as a novelty, like one does with their pets, to get around the trouble of memorizing dozens of similar sounding identification numbers.
In a lot of ways, the life style of an interstellar ark would be best visualized by watching ant or bee colonies. No one is "special"... you're simply there to plug up a particular hole in the wall where someone else inevitably failed at the task.
8==8 Bones 8==8
If we do send an ark, and it arrives an odd 70 years later, the crew will be thoroughly pissed off. Because in the meantime, here on earth we would have invented Star Trek Physics (tm) and can get there in half an hour. So they would arrive at a fully colonised Holiday Inn Resort Planet.
People who think they know everything are a great annoyance to those of us who do.
This reminds me of a scenario someone once brought up at a party (actually, a wedding reception -- there were a lot of geeks there...). It goes like this:
Imagine that you have a really big computation task to perform, and you have a budget of $10,000 to buy the equipment to do the computation. You do some calculations and discover that if you went out and bought the equipment and started it right now, it would take 5 years for your computation to complete. But let's assume that Moore's Law (and/or the popular bastardization thereof) operates very predictably so that at any point in time, the computers you can buy at that time are exactly twice as fast as what was available 18 months before for the same price.
So, what is the optimal thing to do? Buy your computers now, or procrastinate and buy them later? It turns out, if you buy the computers now, your computation will run for 5 years and thus complete in 5 years. But if you wait 18 months and then spend the same $10,000, you will get computers that are twice is fast. Then you will start the computation in 1.5 years and it will run for 2.5 years, finishing after 4 years, which is a year earlier than if you start right away.
So in that case, the optimal strategy is clearly to procrastinate. You may be right that procrastination would be the optimal strategy for the space ark problem as well.
That's one alternative.
Another has been kicking around the theoretical star-travel circles for a while now: Make a VERY small (1Kg) instrument package, put a sail on it, then fire some big lasers at it. For the cost of the ark mentioned in the article you could set up the infrastructure to send out a lot of these packages at a sizable fraction of the speed of light. You'd be able to get decent data about planets in the Epsilon Eridani system within a century; assuming the reports were positive, THEN you'd send out the ark.
After billions of years the human race is all over the galaxy, few billion years later and its all over the universe. And then what? We cling on for dear life as we exploit the last few sources of energy as black holes swallow up any traces of our fantastic achievements. We can exploit the fact that there is an imbalance between matter and anti-matter in our universe, with matter totally dominating. Just as you can flip a Flatland quarter from heads to tails by a 180 degree rotation through the third dimension, you can flip a left shoe into a right shoe by a 180 degree rotation through the fourth dimension, and every particle in that rotated shoe will have opposite spin and charge...in other words, it will be an antimatter shoe. Put the two shoes together in a closet and you'll release far more energy than it took to do the flip trick. This can give us another few billion years. Of course, the result will eventually be a universe where matter and anti-matter are thoroughly mixed, and if you grab any quantity and try your flip trick the result will be indistinguishable from what you started with. But this will give us the time we need to think of something else.
A better question would not be "why do civilised people buy cars, motorhomes, and boats ... etc." but why do said people not abandon their homes, and cubicles, and all their other civilized accoutrement and live an ideal existence as hunter-gatherers? For that matter, why buy a motorhome: all they're doing is taking their "civilization" with them! Your presumption is that people buy those things because they have some inbuilt urge to return to a "better" way of life. I disagree strongly: the bulk of us have no problem recognizing that the civilization that you disparage offers us many things that a simple hunter-gatherer economy would not, could not. Be careful of drawing specific conclusions from a (from my perspective, aberrant) subset of the population.
... indeed, perhaps they would have done some of the overrunning. Anything else is just sour grapes.
... or them? Here on Earth, the competition has been for land, in space, it may very well be for colonizable worlds. If our scouts don't find them, others may get there first: they may already have for all we know. I'll put my money on the explorers ... when the big ships come for us I'd like us to have a few colonies elsewhere.
I consider myself reasonably civilized (I don't own a gun and haven't raised a fist since grade school) but after having gotten the whole camping thing out of my system decades ago I feel zero desire to bond with Mother Nature, ever again. She's a bitch, pure and simple, and after she washed me down a hill in my tent into a lake I had enough of her. I also don't watch TV and I don't buy anything from advertising. Admittedly, however, I do work in a cubicle, for now. But you know what? I wouldn't trade my access to medical care, my Internet connection, my work as a software engineer, and my nice, comfortable bed to live in your world. Too civilized, I guess. Oh well, that's my problem.
Now, I'm not entirely sure why you would expect Stephen Hawking (a physicist, after all, not a sociologist or cultural morphologist) to bother coming up with a rebuttal to your view of civilization. Regardless, one might ask how different life would be had other cultures, over the past thousand years, shown the same interest in the rest of the planet that the offspring of a small part of north-Western Europe did. Perhaps they'd not have been overrun
Getting back to the topic at hand, the spread of our kind of life to other worlds, ask yourself this question. If (and yes, it's a big if) there are other civilizations in our corner of the Universe, creatures that might very well see us as a threat (or at least as competitors), would you rather we come out on top
No matter how you look at life in your idealized world, there is always something that wants what you have. That is the nature of existence on this planet: it is the nature of life itself. What you're really complaining about is that, historically, some people showed more aptitude for this than everyone else combined, and part of that aptitude was expressed as a willingness to explore and take measured risks for some perceived gain. Personally, I don't consider that wrong: cows in fields aren't curious, and I know which I'd rather be.
The higher the technology, the sharper that two-edged sword.
Apparently, wikipedia doesn't like trailing slashes at the end of URLs. Try: http://en.wikipedia.org/wiki/Orphans_of_the_Sky.
Plan 9, surely?
Wasn't there a movie some time ago about this very thing?
A group was sent into space with everything they would need to be "self replicating" until they reached the destination...but as time went on, technology got better and later travelers arrived at the destination first...then when the first "ark" of people arrived they found a fully developed civilization that had meen there for at least a hundred years...
Wouldn't it be better to just wait?
--E--
We don't even have to wait that long. All we need to do is build a space telescope with sufficient resolving power - which is simply a function of size (and not even continuous size, necessarily... see the various multi mirror / multi antenna designs we use now) and precision - and we can look and see what the conditions were ten years ago (for D=10 LY) and then decide if we want to send anything at all. No need to launch anything out of the solar system; the information has been coming our way all along. We're just not (yet) capable of resolving it, but it doesn't even depend on new technology - just lots of materials, and space-based manufacturing to make it practical. Even if something is 500 LY away, we can still see what was happening 500 years ago. Much faster turnaround than the fastest light-sail technology could provide, which is transit time + message back time - at least twice as long. And of course it would benefit us in many ways to build such telescopes.
It seems to me that the optimum method would be to start an automated system that just keeps making the telescope bigger using materials culled from asteroids, comets and so forth. The longer it runs, the more detail we cold resolve. Why ever turn such a system off?
I've fallen off your lawn, and I can't get up.
> I venture to disagree, strongly. So far the explorers have only been fortunate, on the whole, for white men of Indo-European origin.
And for the presumably black men who first stepped out of Africa...
Sheesh, evil *and* a jerk. -- Jade
a) Find a better/cheaper way into space than chemical rockets. Space elevator / maglev launch system / whatever. As long as it doesn't involve strapping huge amounts of volatile chemicals to our payload.
b) Colonize some of the non-Earth objects in out own solar system to gain insights into how to live best on asteroids (plents of 'em out there, a dime a dozen), rocky worlds that need major terraforming (Venus/Mars), moons of gas giants, and dwarf planets. The chances of our would-be interstellar colonists finding any of the above at their destination are almost infinitely higher then the chance of finding another Earth. And, hey, there's plenty of real estate in our own solar system to spread to. One step at a time - not colonizing our solar system before heading to another would be like Columbus trying to get to the moon instead of sailing west.
c) Manage to send an unmanned probe to another star system, to get the kinks in the propulsion/astronavigation/etc systems worked out.
d) Get energy-positive fusion working. Seriously. Without it, doing anything major outside the orbit of Mars is going to be a royal pain in the ass.
Also, we should not:
a) Totally trash Earth before we're ready to haul our collective asses to some other place. Once we need to spend the majority of our resources on just surviving, our chances of getting to anywhere outside our solar system are about as good as finding an ice cube on Venus.
b) Get wiped out or wipe ourselves out.
It seems to me that the optimum method would be to start an automated system that just keeps making the telescope bigger using materials culled from asteroids, comets and so forth. The longer it runs, the more detail we cold resolve. Why ever turn such a system off?
do you really want that big of a magnifying lens to exist? let alone have it's focal point you planet?
Are we trying to figure out what the ants feel just before they get fried?
Do not look at laser with remaining good eye.
Does anyone think we can afford that? The U.S.'s manned space and Moon/Mars initiative is strangling NASA and forcing it to shut down many of its science programs (here, here, here, here, here). It hasn't even started to get into the real spending for a Moon mission, let alone a Mars mission.
An interstellar mission would cost orders of magnitude more than an interplanetary mission. Who would ever fund it? Even an international collaboration would be hard pressed to put together much more than the currently planned Mars mission. And governments wouldn't be too keen to start a mission that can outlive entire nations before we hear the results.
"Frontier spirit" just doesn't cut it against those scales of money and time.
The only thing that likely could spur a manned interstellar mission, barring drastic improvements in technology, is the impending destruction of human civilization — and who would see that coming in time, with enough certainty, to spur the development of a crash program like that? (Especially given the wars likely to ensue if people are that sure of the annihilation of the human race.)
No, I don't see it happening unless we get much, much better technology. It costs enough just to lift things off Earth, let alone build and launch a working intergenerational starship. (The economics of space development given launch costs and the absence of space industry is an extra can of worms... and I am also not economically optimistic of the development of orbital factories or space elevators or the like.)
OK folks, we've all seen this before. Arthur C. Clarke used the very same premise for his notion of interstellar travel when he detailed the craft depicted in his popular Rama series: http://en.wikipedia.org/wiki/Rendezvous_with_Rama Unfortunately, not everyone cooperates over a span of several centuries, so this doesn't sound likely. Personally, I can;t even handle a weekend at my parents... ;)
Why ever turn such a system off?
That will be answered by our returning descendents when all they find is one big telescope floating in the space that used to be our solar system.
man, I feel like mold.
This is a technologically lousy solution, even considering the 'classical' case. I wrote an article a while back on a FAR better, obvious approach on usenet. Will link if anyone is interested.
.9c, because beyond that blue shifted photons would start to destroy any conceivable spacecraft.
Essentially, a much better approach is to leave one's entire engine behind and electromagnetically accelerate 'smart pebbles', pieces of matter with enough nanoscale smarts and nanoscale engines to adjust their course slightly. These pebbles would enter a long ring of magnets in the spacecraft's engine, be deaccelerated to rest relative to the spacecraft with their energy stored in accumulators. This energy would then be used the accelerate the pebbles the opposite direction, doubling the momentum transfered.
Advantages - no rocket equation, you do not carry fuel with you
- far more efficient than a laser sail because the spacecraft has a MUCH narrower cross section (a few square meters) and most of the pebbles make it, instead of wasting their energy.
For deacceleration you throw away half the spacecraft and have it fling back the pebbles.
Top speed would be a target of about
You don't carry human crew, but self replicating machines. Quantum teleportation (a practical technique, demonstrated in the lab) would be used to transmit the key memory state molecules of a human brain.
They seem to have forgotten option 4: wait for robots to take over the world and then send them out to colonize the galaxy. An intelligent robot would not need tons of material or labor to travel the galaxy, not when they can switch off and on at will. They can switch off when they leave the solar system, spend 500 years in deep space, and switch back on when they reach their destination. It's the exact same concept as freezing people to travel, but without the life support and insane shielding.
Absolutely correct. There's enough material in our solar system to support hundreds of trillions of human beings. Thinking about sending giant arks to other star systems over several hundred years does seem to be putting the cart before the horse.
I'm in the hole of the broadband donut.
That's got to be the crappiest return on investment for a Berserker scenario ever. If you get wiped out by hyper-intelligent super-efficient warlike AIs you can console yourself that at least you just lost out to something more advanced on the galactic level food chain. But being annihilated by a badly programmed telescope construction project has got to rank up there in patheticness with having your planet demolished to make room for a hyperspace bypass.
This Space Intentionally Left Blank
To build an ark and fly 10.5 lightyears with it is not an easy task. Right now we have problems sending people to Mars, due to radiation problems, cooling problems etc. I've read an article about required technologies for a Mars trip in the German version of the Scientific American (Spektrum der Wissenschaft) . They discussed several techniques for the shielding. None of them was really applicable. The energy supply is also a big problem. You cannot use nuclear fission (or fusion if it will work some day) because they produce heat. Heat, in space, can only be radiated. So a classic heat sink will not work, as there is no air which can mode the heat away. Every quantum of energy, produced on such ark must be radiated. This is quite tricky. Nowadays satellites are low power systems, which have to radiate only small amounts of energy. Therefore simple foil-based emitters are enough.
The next problem is. To get everything up in space. This is a very energy intensive task. As the ark must be really big. Bigger than a pleasure cruiser. Far bigger. Beside the cost, this will have a significant impact on the ecosystem on earth.
The last big problem is the life support. Projects like Earth II failed tragically. So there is work to do on this end also.
To sum it up. We need some real technological advances before we can start to build the ark. And one is to implement a working energy support for this space ship (earth), which works and cooperates with the life support system. Also we have a resource problem in other areas as well. So this has to be solved too.
This could lead to low power technology, which would at least solve problem one of the ark.
Come on, Mars has more than enough moons; nobody would miss Phobos if we were to carve it out and turn it into a giant colony ship...
USE HOT GRITS WITH STATUE OF NATALIE PORTMAN (NAKED AND PETRIFIED)
Any robut smart enough to rear children is simply going to refuse to do so.
"He's using a quantum encryption scheme! That'll take hours to break!"
by building a gigantic Ark of several miles in radius
You're supposed to measure in cubits, you damned heathen!
Table-ized A.I.
In fact the teaching of Latin to children who were expected to go on to professional jobs did not cease to be general (in the UK at least) until the late 20th century. By then it was largely symbolic, but it shows how long these things persist. It was also advantageous in that it made the learning of the Romance languages (French, Italian, Spanish, Portuguese, Romanian) so much easier.
It's also worth noting that Chaucer lived around the 700 years ago mark and it only takes a few weeks for an English educated person with a little Latin to be able to read the Canterbury Tales in the original. I can also read Dante in the original with a little help from a crib, also about 700 years ago.
Pining for the fjords
If you read the article, a lot of the discussion is based on how long it will take to actually *build* this monsterous ark. From my (I'll admit somewhat limited) knowledge of the progression of science in the area of building something like this, it seems more realistic to sink money initially into the construction of such a vehicle regardless of the propulsion, etc. Thus, we could have a large man-made space-station/vehicle that is constructed using progressively newer and newer technologies (since it is relatively close by), but is not tied to earth's gravity, making it easier to maintain and possibly to launch.
When the time comes to add propulsion, we will have progressed much more in terms of the physics of star-drives. If we haven't progressed enough? Leave it there, have a space colony, send it to mars and back, whatever -- it's not like it's going to be a waste... Think of the sheer magnitude of the construction effort to build this thing and how much easier it will be in the future to design an ark if we already have a gigantic shell to work with.
Think about star trek when they first develop the warp engine. What comes next? The enterprise wasn't built in a day for sure...
When did the idea of a multigenerational ship become "new" speculation? Science fiction writers have been writing about this for many decades.
The tyrant will always find a pretext for his tyranny - Aesop
I postulate an intelligent robot and you quibble about the on switch. Somehow, I don't think that would be the problem.
Ever read "The Galactic Whirlpool"? One of those Star Trek stories set just after the original series. The Enterprise stumbles across a "generation ship" which had left Earth only just before they discovered warp drive, but had escaped attempts to locate it. The inhabitants had forgotten they were on a ship, to them it was "the world". They had collapsed into a primitive society.
...
Since they were humans from Earth, the prime directive didn't apply (not that Kirk was very good about that anyway), so it was left to the Enterprise crew to drag them kicking and screaming into the 24th century
That's a common theme in Sci-Fi though, generation ships where the inhabitants believe the ship is the world, and forget the mission. How does anyone keep at a task for 700 years?
I'm probably not the first one to point this out. There's room in the solar system for several thousand years of unchecked human growth. Let's fix up the house first before visiting the neighbors.
And the Polynesians ... and the original Native Americans.... Can't forget them.
They weren't forgotten. The Polynesians and the Native Americans were all descendants of those brave souls who walked out of Africa all those years ago.
When our name is on the back of your car, we're behind you all the way!
..of humans-serious urbanites- who spend the vast bulk of their entire lives inside of man made rooms, voluntarily, and actually pay money for that privilege. So what's the diff if the "city" is nailed to the ground or floating around yonder space?
I don't think getting people to live onboard a huge ark ship would be all that hard, and it would be well tolerated if it was large enough/designed with some "great" rooms for enjoyment as an alternative "outdoors", and balanced with the population on the ship after some research. I don't know how much squarefootage per person they would need, but it isn't much given the contentment with crowded cities you can see. No additional evolution required really. Have an ark "replica" on the ground, all volunteers, after initial screening, for the final test, must undergo six months inside of that to weed out folks who just can't hack it. You could probably also get some psych studies from the cruise ship industry and from various navies submarine services, and from Antarctica research colonies to see what problems arise and how they are overcome. Prisons wouldn't be good to study because it is the opposite of voluntary.
Call me crazy, but I don't think the purpose of life is to be an utterly expendable cog in a highly efficient inhuman machine. Nor do I think that human beings are nothing more than fully programmable robots who can be instructed to behave and feel in whatever fashion is most profitable to society at large. I believe that any social planners who mistakenly make these assumptions will be doomed to watch their planned societies quickly crumble before their eyes. In fact, history has provided us with many examples of this happening. When are we going to learn our lesson? Planned societies don't work. Civilization can only thrive when people are free to be human beings instead of mindless worker bees.
Looking at the nearest star systems for a decent system to visit or colonize, it is a tough call. There are only 7 star systems within 10 light years of ours. Four of those (Wolf 359 at 7.8 light years, Lalande 21185 at 8.3 light years, Luyten 726-8 A and UV Ceti at 8.7 light years, and Ross 154 at 9.7 light years) are red dwarf flare stares, which produce very little heat and emit frequent (hourly, daily, monthly) extremely high radiation flares that would kill any known living creatures close enough to derive energy or warmth from them. Also, the red light from these stars would not be conducive to photosynthesis for plants as we know them.
One near star system (Sirius A and Sirius B at 8.6 light years) seems a bit more promising. Although the system is fabulously more rich in heavy elements (metals, etc.) than our own star system (or any other in the area), Sirus B went nova a couple hundred million years ago and probably sterilized any nice planetary systems of atmospheres, water, or life (that's an educated guess, but . . .). Also, at 8.6 light years away, it is quite far.
Barnard's Star (at 6 light years) is a red dwarf, but not a flaring one. It's one of the oldest systems in the area, and quite calm. Of course, as a red dwarf it puts out little energy. Still, at the second closest star system it might be a potential place to visit or find rocky planets around.
The last and most promising star system within 10 light years is actually the closest--Alpha Centauri A, Alpha Centauri B, and Proxima Centauri at 4.2-4.36 light years. Proxima is a red dwarf, and a flaming/flaring one, but is far away (one-fifth of a light year) from the other two stars and is therefore negligible. The other two are yellow or orange stars, a bit less or a bit more powerful than our Sun, with good light for photosynthesis. Although a dual-star system, planets within 2 AU of either star (about the distance from the Sun to the Asteriod Belt past Mars) would not greatly be affected by the gravity of the other star. Liquid water could exist within about the orbit radius of Venus for the smaller star, or Earth to Mars for the larger star. The system has twice the heavy element content of our own system.
At 4.36 light years, and the closest neighbor we have, why not try going there instead of Epsilon Eridani at 10.5 light years? You'd save well over half the time, whatever method you used to get there! G-forces aside, if you could average 10% the speed of light, it'd take about 50 years one way.