I'm cautiously optimistic. I temper my hopes here with the reality that, in our solar system, it so far appears that only 1 planet in 8 harbors any life at all (though, given the literally dozens of moons in the outer solar system yet to be rigorously examined, there's perhaps another orb around our sun that may have life on it yet to be detected; though certainly not technologically advanced life).

Agree with your assertion and Nigel's, however: given the overwhelming scale of the galaxy (much less the universe), it's highly unlikely that there aren't inhabited worlds elsewhere (there's much research that indicates binary solar systems - much more common than single star systems - may, in fact, produce conditions far more favorable for life, in fact, than our solar system), and life likely goes inevitably from microbes to complex & intelligent beings (thanks to natural selection & game theory).

I don't think there's sufficient evidence to substantiate the claims of extraterrestrial visitation. Some stories are more interesting/compelling than others, but the hard proof is always lacking.

While interesting to think about (and, personally, I find the notion of parent/daughter universes that are reproducing easier to intuit than most explanations of the origins of the universe), there's no present way known for falsifying this idea. Not that there's anything wrong with the speculation; I just don't think it'll ever pass muster as conclusively true or untrue anytime in the near future.

Well, we would simply require a lot of energy to attempt to create one. We don't have anywhere near the capacity to do this, but perhaps may in the future (if we ever create an artificial sun, for example). I think these are one of the best speculative candidates for 'cheating' around relativistic limitations.

Well, while we (sort-of) know that space can be 'bent' (we call such phenomena 'gravity' ), we can see the extreme end of what severe bending can do to things attempting to traverse such a well (see: the effects of black holes on surrounding matter). I don't personally think that this is a very good speculative candidate for long-distance travel.

Well, we would simply require a lot of energy to attempt to create one. We don't have anywhere near the capacity to do this, but perhaps may in the future (if we ever create an artificial sun, for example). I think these are one of the best speculative candidates for 'cheating' around relativistic limitations.<

What if we harnessed the natural sun's energy?  Or maybe antimatter-matter reactors of some type.  We can collide antimatter with matter, but doing this on a large scale where the energy output is much greater than the input is the problem.

 I tend to come down on the side of extreme skepticism about most sci-fi technologies.  The thing is, energy is a pretty damn hard thing to come by in most cases.  We've been very lucky to have discovered an easy source of stored energy in fossil fuels -- one that releases a lot more energy than it takes to cause the release.

It's one thing to just glibly spout off about harnessing the energy of a star, but a star's energy is extremely dispursed, and any method of capturing, storing, and converting that much energy is going to require a collosal amount of energy to begin with.  You don't just put up massive collection grids all over the solar system.  Getting out of earth's gravity takes a LOT of energy.  

Fossil fuels are going to run out soon.  When they do, humans are going to be at a very interesting crossroads.  Sure, nuclear energy is a big payoff, but nuclear fuel is not unlimited -- far from it.  Solar, wind, and alternative combustion fuels are all nice, but they're going to have to work extra hard to equal fossil fuels.

Particularly with respect to things like Star Trek transporters, the energy requirements would be phenomenal, not to mention the sheer volume of data that would have to be flawlessly translated, digitized, and retranslated.  Consider that if your DNA were stretched out end to end, it would easily stretch to the sun and back.  That's just your DNA.  Your brain contains around a hundred billion neurons.  In short, to accurately render a human as digital information would require trillions of trillions of bits of data.  Not trillions and trillions... trillions of trillions.  That's just the data requirements.  Now, think of the energy it takes to move up or down a couple of spaces in the periodic table.  It takes a damn nuclear fission reaction to take hydrogen apart, and it's the simplest element.  Not only do you have to take trillions of atoms apart, you have to control that energy and then somehow put it all together again.  Controlling energy takes energy.

Put simply, the act of deconstructing a human, leaving only air behind, and then reconstructing it in another place would take as much energy as running the world for a week or so does now -- if you were really lucky.  I'm sorry... all this beam me up, beam me down... oh, shit, I forgot my pen... beam me back up again shit?  No fucking way.  Maybe one day we can hope to transport a few molecules a couple of nanometers away from their original position, but no... star trek transporters are not gonna happen.

I'll need a physicist to back me up on this, but I'm pretty sure the laws of physics would have to be drastically wrong for this to be a possibility.

 I'm not accepting victory because I don't have the knowledge to do so.  I am interested in getting a physicist to tell me if I win or not, though.  Maybe deludedgod will weigh in on this at some point.

My hypothesis about life in the universe: Life is fairly rare, but plentiful. Our galaxy probably has numerous planets that support life, though probably much less that one planet per star. On the other hand, intelligent life is extremely rare at this point. My hypothesis is that our galaxy probably only has one space-faring life-form: Us.

The reason is actually quite simple. If we look at the history of life on this planet, it took billions of years just to get to multicellular life. Then it took hundreds of millions of years to get to animals with big brains. Then it took tens of millions of years to get animals with culture. Then it took a couple million years to get animals with basic tool kits. Then it took tens of thousands of years to get anumals organized in civilizations. Then it took thousands of years to get science, then hundreds of years to get computers, then decades to get spaceflight, then years to get a global network, etc.

Basically, it's an exponential technology curve. Once humans got their basic toolkit in order, it only took a few thousand years to spread around the whole planet. In the span of life on Earth, that's a blink of an eye.

Once we managed to leave Africa, it didn't take long for humans to be everywhere. The spread of technology is exponential in nature.

Once we manage to create a stable biosphere off of Earth, the spread throughout the rest of the galaxy is just a short matter of time. We will exponentially spread first throughout our solar system, then eventually to another star system, then inevitably we will permeate the whole galaxy.

Assuming we don't blow ourselves up first.

So, with that scenario in mind, you just have to ask yourself, "Assuming there is space-faring life elsewhere in the galaxy, how long would it take them to permeate the whole galaxy?"

And that's not a very difficult thing to estimate. If we assume that FTL is impossible, but speeds at a small fraction of c are possible, say, 0.01c, and that the Milky Way is 100,000 ly in diameter, then the travel time from end to end would be 10 million years.

So, once a technological life-form gains space-faring abilities, an approximate estimate for the time to premeate the galaxy is about 10 million years, give or take.

Even if very conservatively we say that it's more like 100 million years, let's look at the likelihood that there's another space-faring life-form that has been around for ~50 million years (enough time to fill up about half the galaxy).

The age of the sun is 4.5 billiion years. The age of life on Earth 3-4 billion years. So, we can assume that when stars form, life (if it is to arise at all) arises fairly soon after the planets condense.

50 million years is only about 1-2% of the entire span of time life has been around in this solar system.

Think about this for a second. A star has a planet that support life. For 98% of the time, the life is planet-bound. Then, suddenly, poof! That planet generates space-faring life and suddenly that life permeates the whole galaxy. This is how it would be for any stellar system that generates space-faring life.

What this means is that if there's a star out there that spawned space-faring life, and we *just happen* to develop space-faring technology within the same time frame, the odds are greatly against it.

The average age of stars in the Milky Way is about 6.5 billion years, which is older than the sun. The oldest star is about 13 billion years old. Within that time, no star has spawned space-faring life. If it had, then space-faring life would be everywhere, and it would be a miracle that we wouldn't have encountered it.

What's worse is that the more likely it is that space-faring life can develop, the more likely that it already has, and that it already permeates the galaxy. Since we don't see any evidence of this life, then it stands to reason that space-faring life must be very rare.

In fact, the only scenario that makes any sense is if there is *exactly* one other space-faring race out there, and they just haven't made much progress yet. If there were more than one, then the odds would be *really* stacked against the idea that we all just *happened* to develop space-faring within the same 50 million year time-span. The more space-faring life there is out there, the less likely it is that they all happened to develop at the same time. Thus, *if* there is indeed other space-faring life out there, the highest probability is that there's only *one* other instance of it.

Imagine that each planet that harbours life is a runner in a marathon. But the tricky thing is that each runner has started at a different time, runs at a different speed, starts at a different place. The only common thing that ties them together is that they will all finish at the same spot (permeating the galaxy).

As we (one of the runners) approach the finish line, we can vaguely see the finish line. There's no celebration going on, there's no winner obviously standing on a podium holding up a trophy. We are 98% finished the race. Only 2% more to go. Some runners may have approached the finish line, but ran out of steam, hitting 'the wall', as they say, and were unable to finish the race. We ourselves might still hit that wall. But we can definitely see that there's no evidence that any other runner has finished the race.

Since we know that we've been running four about 3-4 hours, and of the marathon we only have about 840 metres to go, and we know that the other runners *could* have easily started 6 hours ago, or even earlier, we start to wonder: Maybe we're the only ones within sight of the finish line. Maybe there are no other runners. Maybe there are, but they all hit the wall. We've got a relatively late start in this race. 

Maybe we're just the fastest? Hmmm. Could be. What are the odds? I'm no statistician, but I think a good case could probably be made that the odds that we are the first space-faring race are much better than 50/50. Probably closer to 90%.

Remember, I've used what I consider pretter conservative estimates. For example, I think it's likely that we'll be able to develop space travel significantly faster than 0.01c, say maybe .05c, in which case, we're actually only about 2 million years from the finish line, which is about 99.95% finished the marathon, which is less than 30 metres from the finish line, and no competitors in sight.

I think 90% is a very safe estimate that we're the first space-faring life in the Milky Way. A corollary of that is that, assuming we don't blow ourselves up, we could have a galactic civilization in less time than it took humans and chimpanzees to diverge from our common ancestor.

You win. It's a violation of the conservation of energy.

 For clarity, the only reason I wasn't prepared to accept victory on my own merit is that I have only read about anti-matter in science magazines.  I don't have any actual class time studying it.  Even though I felt pretty confident that I understood my basic point, I didn't have the scientific right to speak as an authority.  All I could say was that I felt very certain because I thought I was repeating what I've heard reputable physicists say.

Well, to be honest, you are inviting me to out myself. So let me just do this and get it over with.

I have, over the years, had a few people with PhDs ask me “Where did you get your degree?” The unvarnished truth is that I have no degree. What I have is a thirst for knowledge that cannot be satisfied by the paper chase. Don't get me wrong here, people like bobSpence1 and DG have done the paper chase and they know what they know. I will not be able to add to some parts of what they say.

However, that does not mean that stuff cannot be meaningfully addressed. The role that I might play would be the one that encourages people to as further questions.

I am in the same boat as you, as evident by my posts earlier.  But a bit less learned in the physics behind antimatter.  And as for my post earlier when I said, "when we can get more energy than we put in", well I just screwed up.  What I meant to ask was if we could produce antimatter as a form of fuel.  I am recovering from salmonella and I'm dehydrated.  Sorry for the stupidity.

... and that's just the first problem with it. We're not talking about small amounts of energy when we create anti-matter. If we were able to create enough energy to use anti-matter in a propulsion system (which doesn't make sense anyway), then we'd just make that the propulsion system.

[edit: by "that", I mean whatever it was that got us all this energy in the first place, because it's a lot.]

I knew what you meant.  I figured you know that over unity is impossible, and I got that you were saying, "If we could figure out a low energy way to make antimatter to be used for fuel."  I think that's pretty much saying the same thing as over unity, though.  It's one thing to put some algea in a pot and let them eat and shit some oil (neat stuff, by the way) but that's a chemical reaction.

 Dammit, Will.  I was halfway through writing that he should take deceleration into account and thought... Gee... I ought to see what Will wrote.

I've done this routine before, but for shits and giggles, I'll mention some of the more important points again:

1) Radiation = Death.  Shielding = heavy.

2) Prolonged weightlessness = death.  Artificial gravity = added size to a spaceship = added weight.

3) Lack of social interaction = madness = death.  Enough people to have a society = added weight.

4) Malfunction at any point during a multi-year journey = death.

5) Being slightly wrong about the destination in virtually any way = death.

6) Drinking nothing but Tang for 12 years = death.

7) Lack of sunlight = death.

I don't feel like going on.  The point is, technical hurdles to deep space travel are brobingdagian.  The technical hurdles are also just the first problem.  The human problems are much harder to solve.  Try committing ten trillion dollars to sending people on a space mission that won't be resolved until all the taxpayers who funded it are dead.  Good luck with that.  Try committing ten trillion dollars to space exploration while Sally Struthers can still find starving African children.  Try convincing twenty people to commit to spending the rest of their lives in a tin can.

Oh... and don't forget, if you're sending people that far, you're going to have to send them with enough supplies to build a habitable environment, even accounting for bad scouting reports.  That's a lot of added weight.

To me this is like someone saying, back in Babbage's day, "A calculating machine that can simulate the weather? Why, you'd need billions of gears, and we all know how unreliable clockworks that delicate are. The thing would be the size of London. You'd have to hire the entire country just to perform routine maintenance on it!" Or, in Turing's time, "Do you realize how many vacuum tubes you'd need? It would be enormously expensive. Let alone the power requirements!"

Radiation is only a problem close to the star. The ship can pick up an asteroid on arrival for protection at closer orbit.

You don't actually need to send living specimens. You can easily send a mechanical ship that has the capability to clone humans on arrival. Stem cells can be frozen and protected by shielding. Alternatively, by that time we might have developed machine consciousness, and can simply send mechanical bodies which are booted up on arrival.

This eliminates any risk to human life during transit. You can guarantee mission success by sending multiple craft to the same destination. If the initial payload is small enough, you could send hundreds/thousands of craft.

This again is like saying that gears or vacuum tubes can't lead to transistors and integrated chips without 'colossal' investment. It ignores the fact that small investments can be made and exploited which lead the way to slightly better technologies which lead the way to even better ones, etc.

Travelling to another star is a long way off, for sure. But in between, we will have Earth-orbital environments, Moon and Mars environments, free-floating intra-solar-system ships for transport, asteroid mining camps, etc. Each of these is a small step which leads to bigger and bigger steps.

By the time we try to send humans to another star, I imagine the solar system will be filled with all sorts of self-contained ecospheres at different orbital distances from the Sun, and using different technologies and strategies to survive for long periods in space. The population off of Earth may even rival or surpass the population on Earth.

The thing that will draw people to space is energy. There's a LOT of energy out there. All it takes is for one space-craft to have the technology to self-produce a copy of itself and you're off to the races. This requires the ability to acquire resources (possibly with cooperation from other space-craft, in trade for harnessed solar energy), and the ability to manufacture all the components necessary to copy itself (possibly with the aid of nano-tech or at minimum an auto-factory).

With so much energy and matter resources, if a robust enough intra-solar-system economy develops, then sending a few thousand craft to a nearby star may actually be a trivial investment. Instead of being this monstrous effort you imagine, it may be a "Oh yeah, by the way, let's divert 0.01% of our energy budget to send a mission to Alpha Centauri," situation.

After all, sending Columbus to 'India' didn't break Queen Isabella's treasure chest.

Supplies aren't the problem so much as energy is. Once the craft arrives at the star, there will be plenty of asteroids to harvest for material resources.

The real trick is getting a self-replicating technology/biology bundle across interstellar distances. The hard part isn't actually the interstellar distance, although that too is hard. The hard part is the self-replicating technology/biology part, and that's something that will be worked out in the due course of time while we populate the solar system.

Assuming we don't blow ourselves up first. (Which may be the hardest part of all.)

And that, I suppose, is where the difference between ignorance and intelligence (in the case of the aeronautical engineer) comes into play.  I agree with what you are saying, in the sense that it is a fledgling theory which has no backing.  But I am still optimistic, and believe that we will eventually get to other planets and star systems.  

Mu-hahaha! I live to torment you! Let's continue!

Oh whatever. Like magic robots need shielding. They're magic. Plus, they'll be made in the future. The future has lots of things that are shiny and work great. Don't you know anything?

Uh, duh. Thus magic robots. Sometimes I wonder if you ever even went to school.

As if anything would ever go wrong. Pff. We've landed guys on the moon no problem. Not a single glitch. Ever.

What, you don't like Tang? Okay, I'll stop.

This one RIGHT HERE is what annoys me in every single science fiction movie/show I see. Energy. The Matrix is the best example. The robots keep the people alive as human batteries? Without a sun to grow food? Without potable water to grow food? Food grows. I don't care what the hell you're eating, it had to have been organic at some point, or you'll die. You'll just die. Period. In that ridiculous Matrix movie, they would have needed nuclear plants to operate all that machinery, and they would have needed sun to grow the food. Not only sun, but an entire ecosystem. Because you need an entire ecosystem to have food in the first place. Apparently, we're just learning that now, because people have no idea that soil is required to grow plants. And soil requires lots of micro-organisms to be good soil. No ecosystem, no food. But in Matrix Land, you don't even need any of that. No, you can just magically produce Future Gruel. Everyone will eat only one thing, and nothing will go wrong.

Then the sequel - don't get me started on the sequel. Where the hell do they manufacture ammunition? And WHY, when all it takes is an EMP to down the scary machines? Just carry a portable EMP generator! In fact, if you're really serious about destroying machines, make a very large EMP generator, and use your magical energy source to power it. Just wheel that sucker up to the biggest machine you can find, and WHAM, no problem. It's like a movie full of retards! I could go to war against both sides of the human/robot conflict and win single-handedly. Did they only save the mental cripples?

K, sorry about that. I have some Matrix rage.

I see. Snea-ky.

I had no idea what a Dyson sphere is, but after looking it up, I just had a good laugh. So thank you for that. Short answer: obviously no. Longer answer: the math says no.

Deludedgod, please. Please, deludedgod, please show up and play math with me on this one. I love the idea of transporting X amount of the natural resources of the earth OFF of the earth, just so we can live in space instead, so that it's much more expensive, energy-consuming, and life-threatening. I love it. It's completely retarded. It's even more retarded than the Matrix. It's the most magically beautiful metaphor for the idiocy of humanity I've ever seen.

So let's see ... even for a Dyson ring, we'd need to create a circle of solar collectors with a radius of ... oh, let's say 1,000 km? *snicker* K, so the circumference of this thing would be ... ooh, I can do that in my head: 3,141,600 km. Nice. Let's say it's made up of equal parts solid material and spaces along its length, and divide it roughly in half, giving us 1,500,000 km of space station/solar collectors. Now let's give our collectors width at half the length (like a rectangle), and give the stations a depth of say half a kilometer. Sounds fair. *chortle* That gives us a volume of ... 562,500,000,000 km³. Now, we should assume that only 25% of the volume of these things is actually material, and the rest is empty. That leaves us with ... 140,625,000,000 km³ of material to move into space for these stations .

Should be no problem. If the surface area of the earth is ~150,000,000 km², and with mining efficiency being what it is, it should probably only take a couple of planets worth of material ... TO MAKE HABITABLE SURFACES THAT ALREADY EXIST ON ONE OF THOSE PLANETS.

Whoo! I have a feeling I overreacted there. Feeling a little environmental today.

I have to agree with you there. In the speech where Morbius explains the matter, didn't he say something to the effect of “a new form of nuclear energy plus the battery tanks”?

Huh? Wut?

If the robots had fusion what were the battery tanks for again?

How sneaky could I have been? I posted an explicit declaration that that was what I was doing in large type and bold face.

As far as what we will do a thousand years from now, again, I don't know and I don't care. Unless science can provide a way for me to live that long. Then I will. However, I refuse to cross that bridge until I come to it.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

In any case, you obviously don't read science fiction. If you did, you would have known about Dyson Spheres. You also would have known that a Dyson ring is known as a Ring World.

If you can find the time, I would suggest that you read “Ring World” by Larry Niven. Especially the author's note where he talks about receiving a detailed engineering proposal from Freeman Dyson.

After that, please read "Variable Star” by Robert A. Heinlien and Spider Robinson. The basic presentation is that of an autobiographical work by a passenger on a city sized starship headed for a star fifty light years away.

Well, there's not much more to say.

I simply cannot envision anyone bothering to build a Dyson sphere. This is where the fun starts. A Dyson sphere encloses a star. So if we position it around a star with the same HZ class as our own, to sustain it at liveable temperatures, it would have to have a uniform radius of about 1.5x10¹¹m, hence an SA of about 2.82x10²³m². So, if we built it 1 kilometer thick, we need a volume of about 2.82x10²⁶m³. The only way to get that much matter is to take planets to pieces. The earth has a mass of about 10²⁴kg, so factoring in the varying density of the object, you could safely say that you'd have to harvest every last scrap of matter from a few good sized planets, which needless to say is ridiculous since only a small portion of the material present in the planet will be suitable for constructing a Dyson sphere, so you would need many more planets (terrestrial ones too. Gas giants are no good. And unfortunately, gravity limits the size of terrestrial planets). The idea of taking planets apart to build a habitat in space strikes me as utterly ridiculous.

Frankly, the idea of living in space is completely retarded. Fantastically retarded. Surely, if it ever got to the point where we were looking for somewhere else it would make vastly more sense to find other Earth like habitats instead of trying to build one.

I'm just messing with you - I'm in a funny mood, and on the internet. It's a terrible combination.

I has been a while, but I was into science fiction for a bit there. I don't know if you can tell, but I'm one of those assholes who can see the work in everything. Mind you, not "no way, that'll take too long (whine, whine)", but "that should take us two and a half years with three people" and then dead silence. Anyway, unless the writer is really imaginative (like, say, Heinlein) I have a hard time with a lot of the premises. I think Heinlein's "Friday" was a pretty good guess at the future. Corporations becoming as powerful as states, short-distance travel is by horse ... very fun.

I would also know that it makes No Sense. I can stretch my suspension of disbelief only so far. It makes me a dick, I know, but I used to do software project management, and it scarred me for life. A Ring World presents so many immediate problems that I can't even list them. How do you even get past the part where it takes an entire planet just to get the raw materials for the ring? Then you have to get your parking space in orbit just right, and not suffer any orbital degradation.

OR you could settle on a planet. A planet that already has a built-in ecosystem, billions of years in the making. 

Will, I'm not sure you understand what Dyson was conceptualizing. The 'Dyson Sphere / Dyson Ring' is not some megalithic, super-industrial pipe-dream project; it's an (hypothetical) emergent system resulting from reaching into space for more materials & energy. The 'ring' is made out of inidivdual spacecraft / habitats that are self-sustaining, likely adrift one or two AUs from the sun in the asteroid belt, mining away.

Orbital degradation is either stopped by use of solar sails, or by being anchored to an asteroid / dawrf planet.

I'm not sure it's likely, but I hardly find it implausible.

Oh, I get it all right.

Certainly not megalithic ("big stone" ), as it's broken into disconnected parts, making trade and transportation more difficult, but definitely a super-industrial pipe-dream.

Mining away on what? And who wants to be the first couple of spaceships out there without supplies? "Self-sufficient" is a tall order. A really, really tall order. As deludedgod wrote, there's the problem of heating these ships, for one thing. Then there's gravity. Oh, and getting enough sunlight to grow plants. Oh, and ...

Both of those things involve the input of so much energy that I don't know why anyone would do it.

I just find it unlikely that anyone would have the kind of resources to continue to want to do it. It's like trying to set up a gated community, only one that hovers two meters above the ground at all times just in case. Only times a BILLION.

Well, I can understand if you don't like arguing about it, but you replied, so I'm going to reply to your reply. Feel free to reply, or not.

Except D&D was about mythical creatures and magic, and this is about technology and science... Slightly different.

Just for the record, I'm not supporting warp drive or teleportation or any of the 'magical' sci-fi stuff (and yes, I did call it sci-fi, as in the pejorative). I'm sticking purely to what we currently know about physics, plus conjecture about technology based on reasonable trends.

Definitely with you there.

Still with you.

I won't be mentioning wormholes or anti-matter or force fields. Pretty much just basic technology. Maybe the furthest I'll go is fusion. Maybe quantum computing, but not probably not. Maybe nano, but not the 'build anything you want' kind, rather the kind we already have, extrapolated out based on current trends. In fact the most important technologies I'll require are ones that are pretty uncontroversial: Biotech and manufacturing.

Agreed.

Most likely, we'll be using genetic engineering, prosthetics, tissue cloning, stem cells, and various other technologies to prolong life.

We may even eventually get machine consciousness, but my argument does not rely upon it.

Maybe we will. But we'll also be arguing over things we can't even imagine right now. A thousand years ago, who would have imagined that we'd be arguing over weapons that could destroy all intelligent life, abortion, cloning, pollution, whether a woman could lead a country or even the whole world, etc. etc.? The world today is very little like it was 1000 years ago.

I predict three possibilities: In a thousand years, we are either extinct, in a massive dark age, or we are way incredibly beyond where we are now. The possibility that you seem to be promoting, that we are basically as we are now, but with slightly more interesting toys, is in my mind incredibly unlikely. You would have to ignore all the technological and cultural trends of the past three thousand years. Suddenly, in 2008, we are at the apex, and there's nowhere to go from here. Doesn't wash, in my view. We either follow the trends up, or we crash, and possibly burn.

My argument doesn't require uniting as a race. It only requires surviving long enough to create self-replicating biospheres in space.

----

There is nothing implausible about sending a mechanical ship to another star. We already have Voyager 1 and 2 on their way to interstellar space, and that was with 1970s technology.

The only trick is to have that craft a) survive and remain viable for the whole trip, and b) transport enough technology and energy to re-create consciousness once it arrives at its destination.

These are not 'magical' scenarios. NASA has already researched several different methods of interstellar travel. They think they can get to 0.1c. My scenario doesn't even require that. It could work with 0.01c. That would make the trip to Alpha Centauri somewhere in the neighbourhood of 1000 years, and that's with my conservative 0.01c. A thousand years in interstellar space is nothing to a machine. It doesn't even have to be operating. Interstellar space is like the best possible preservative, compared to conditions on Earth.

Even if the chance of failure is 90%, just send 50 of them, and your chance of failure drops to less than 1%.

Problem: There is only ONE of those planets. It has limited access to energy from the sun, due to its compact nature. One ecosystem can be destroyed by one catastrophe.

Solution: Spread out. There can be multiple ecospheres, which by their nature can survive numerous catastrophes. The more spread out you are, the greater access to the Sun's energy.

You don't need to have a Dyson sphere. That's just a theoretical concept to illustrate an idea about how to detect if there's advanced life out there in the universe. It doesn't actually need to be a contiguous sphere. Imagine a Dyson forest. A bunch of little biospheres, millions, billions, trillions, such that they collectively absorb almost all of the sun's energy. It serves the same role as a Dyson sphere (converting visible light to infrared), but suffers none of the drawbacks you mentioned.

A Dyson forest, by its nature could be built one biosphere at a time, through replication. It is not at any fixed orbit, and therefore can adjust to seek out resources, either energy (from the sun) or material (from asteroids, moons, and eventually planets). It doesn't require a huge upfront investment. It can be grown as big as the material available allows. Using computer guidance and various forms of propulsion, the individual biospheres could maintain mutually harmless orbits, avoiding most collisions. And best of all, no magic is necessary.

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The key thing to realize is that technology is like another form of life. A city is like a colony of bacteria, just a little more complex. All you need is a stable and self-replicating biosphere, and evolution will take over. As we know from evolution, life will spread and adapt to take advantage of *every* niche it can.

The thing about space is, vast quantities of energy to harvest. If biospheres can replicate and harness the sun's energy, they will. It won't take a massive effort to unify humanity, it won't take a huge investment or a complicated plan. It will just happen naturally. The only limit will be resources, and there's plenty of resources in space, especially if you don't have to constantly pull them out of a gravity well. All you need is an economy to trade material resources for harvested energy, and you've got yourself a working ecology.

Initially, it will be just exploration, as it is now. But as the technology becomes refined, it will be more and more feasible to keep humans up for longer and longer periods. Eventually someone will have the First Baby in Space. You *know* that's going to happen. It's only a matter of time.

Assuming we don't blow ourselves up first.

I take offense at that. I *am* one of the nerds.

Whoah, some form of projection or something going on here. I'm definitely not one who proposes solar-system colonization as a way to relieve population pressure, nor am I one who is complacent to wreck the Earth. In fact, that's exactly what I'm fighting *against*.

My whole philosophy poses the question to me constantly: Assuming we do spread out into the galaxy, will we be worthy of it? Will we just become the new interstellar bacteria, consuming and destroying as we go? Or can we become something better?

I am completely against what I call 'consumptionism', which is basically what you're railing against.

However, solar-system colonization is inevitable -- assuming we don't blow ourselves up first. Since it's inevitable, it's worth exploring the idea. It's worth trying to find a way that we can do it without becoming bacteria-with-brains. We cannot just ignore the possibility just because we're dissatisfied with the way things are down here.

I agree, but this is not an argument against colonization. It's an argument *for* political and cultural change down here, and soon.

Major problem with DG's idea: There is only one such planet that we know of.

In the mean time, the only viable options to living off of Earth are sustainable biospheres.

Oh, and Will, notice the word 'sustainable'. That's the ticket for political change down here. That's the argument you should be making. We need a sustainable society for two reasons: So the Earth doesn't die, and so we can colonize space responsibly. The same argument solves both of the problems you've raised.