do you think humans will ever travel to the stars?

[anarch]

Will we ever explore outside of the solar system?

If so, how do you think it will happen? Will we one day come to a new understanding of physics that allows for some way of traveling faster than light?

Or, if it happens at all, will it be in slow-moving craft that are set up for self-sufficiency, I suppose with the assumption of multiple generations of crew, and/or maybe the hope of somehow traveling fast enough (without running into some kind of space-crap and/or radiation and blowing up, and with some kind of propulsion system that doesn't require the entire mass of the galaxy to fuel it) that relativistic time dilation would allow the crew to make it somewhere interesting within a human lifetime?

Just curious what others might think....

[Warpy]

1. Too many technological problems to be solved now

propulsion being the least of them. Of more concern is how to sustain people for weeks, months or years of travel and to sustain the spacecraft in a universe chock full of flying debris. A microscopic piece of space junk can disable anything we have now if it's going fast enough.

Until we manage force fields and replicators, my guess is that we won't be going very far.

[pinto]

2. Yes. I've always thought that science fiction presages fact.

ie, HG Wells and our eventual landing on the moon.

Not saying one is in any way causative of the other, but the possibility is established in public consciousness.

[tridim]

3. Yes, but not with a traditional action/reaction spacecraft

Some day within the next million years or so we'll figure out a way to grab space and pull it toward us and then let it snap back.

[whistle]

4. Yes, watch Carl Sagan's Cosmos series

[DemInDistress]

5. I've been to KPAX... I'll be going back one day .. nt

[Sal Minella]

6. I'd be really flippin happy if we could travel to the next TOWN without

being inexcusably rude to each other.....lets start there.

[Poll_Blind]

7. No point in it: The Tralfamadorian test-pilot ALWAYS pushes the button.

And the Universe always ends.

PB

[Bonobo]

72. And so on...

[Ready4Change]

8. I used to think so, and soon. Now I think maybe, and far in the future.

I used to be far more optimistic. I used to see our species as bold, as a risk taker.

Now, I see that, as a species, we are far meeker than many of our individuals, and as we grow in technological prowess, we seem to also be growing in the ability to chain us all with the power of the lowest common denominator. Individuals may want to look beyond the horizon, but their society fears allowing them the chance.

I see energy as being a problem as well. We seem to have started with a massive stock of cheap energy in oil. With it we have made tremendous strides in technology, while harming our environment and demonstrating the difference between intelligence and wisdom. We now face a future in which our available energy may be insufficient to allow our technology to resist the harm we have done. We may have painted ourselves into a corner.

At this point, I'd say, if we are to reach the stars, it will be long from now. After we have survived the post oil world, after we have learned to sustainably power our population (or match our population to our power generating ability.) From there, I believe we could slowly expand into orbit. And after generations have learned to live and thrive there, chunks of the space born can cut themselves free from their Earthly apron strings, and slowly explore what lies beyond.

But there are signs we can do this sooner. Burt Rutans Spaceship one was a shot of adrenaline. We may leap into orbit yet.

[Ediacara]

9. Yes

I actually think we'll send probes to Alpha Centauri and some other nearby stars in my lifetime (I'm 28, so I'll give myself an optomistic 70 more years), taking maybe 20 years to get there. As for humans travelling to distant stars.... I think that until and unless we develop some sort of engine that can warp spacetime or create wormholes or "get around" the light speed speed limit, you won't have anyone willing to devote essentially their entire life to visit another star, let alone devote their life and the lives of their children to a generational ship.

[rman]

13. 20 years to alpha-centaury - that's on average some 20% of light speed

(at an average equal to light speed it would take some 4 years - in the frame of reference of the space probe, that is...)

At the moment we are not anywhere near achieving those kinds of velocities. I don't think we'll create the required technology within the next 40 years.

Even if we do, there's the problem of relativistic effects messing up the time schedule, and the problem of sending back data across a distance of some 4 light-years. Needless to say that remote control is a no go.

[qazplm]

17. the speed is actually doable..

a light sail could do it, a fusion engine maybe could do it.

the poster above is right that the real issue/problem for short interstellar flight is not necessarily speed/engines but for want of a better word "deflectors", consumables, and protection against radiation both from the engines and from the environment.

All IMO solvable in the long term, but probably not during my lifetime, but maybe my kids or grandkids.

[Katzenjammer]

50. but the environment isn't.

we don't know how to build a closed, human-liveable environment. They break down, and we don't know why. And they don't last anywhere near 20 years. And even before they break down, they can't support more than a few humans--nowhere near enough to maintain a healthy gene pool.

[Ediacara]

26. Well we might be able to in 70 years :-)

I am being optomistic about how long I'll live. I understand it would be extremely fast and out of our reach at the moment, but I think it's acheivable. Eventually. As for being on auto-pilot, that is something I worry about, but as extrasolar planet detection gets better, I think we could create a very specific route for the probe based on which (possible) planets will be where at what time. Hell we could even send several in case something malfunctions.

[Odin2005]

10. Yes.

I suspect it will be somewhat like the future universe in this futurist website I found a week ago:

http://www.orionsarm.com/main.html">Orion's Arm

hard science
plausible technology
realistic cultural development
vast setting
10000+ year timeline
no humanoid aliens


Welcome to the
ORION'S ARM WORLDBUILDING GROUP

Thousands of years in the future, civilization spans the stars, and humanity has branched into myriad directions. Godlike ascended intelligences rule vast interstellar empires, while lesser factions seek to carve out their own dominions through intrigue and conquest. And beyond the safety of the human-friendly worlds, adventure awaits those prepared to risk all.

[AlienGirl]

11. We will probably fail, but that doesn't excuse us from trying

The distances are so great, and the energies to cross those distances at speeds that allow a human to get there in a lifetime are so vast, that it's highly improbable that humans (or any other living being with a lifespan not measured in centuries) could achieve an interstellar civilization.

But it's the only thing worth trying for. Without a foothold in space, Earth's biosphere--including humans--is all trapped on this one little bitty planet like so many eggs in a basket. Humans are Earth's (Gaia's, assuming Lovelock is correct) current best chance to reproduce itself elsewhere. Maybe Earth's only chance. Given that there has not been any evidence for intelligent extraterrestrial life, humans may be Intelligence's only chance in the universe, or even Life's only shot at expanding from the only planet it is known to have formed upon.

So we must try, though it is impossible.

Tucker

[htuttle]

12. It all depends on whether Burkhard Heim is correct or not

He theorized a way that FTL travel might be possible. His theories seem possible, but apparently the amount of energy needed just to test them is beyond our capabilities right now.

But if he's right? Then I think we will travel to the stars (and would make a visitation to Earth by aliens far more likely). If he's wrong, and there really is no way to travel faster than light? Then I doubt that humans would undertake an intersteller mission anytime within the next 1,000 years. Even Alpha Centauri would seem out of reach.

[anarch]

15. I think coming to a new understanding of gravity,

along the lines of what Heim's life work was all about, will almost certainly have some surprising implications as far as this kind of thing goes. The fact that there is no quantum theory of gravity never ceases to annoy me.

[Occulus]

44. I've been following a major discussion of that theory since the

now-famous article in New Scientist. The thread I'm following can be found here.

The math is completely beyond me- and, as I understand it, beyond most physicists without extensive study. All Heim's notes and lectures are in German, and he had to create his own form of notation to get everything down. Fortunately, there are many people working on translating all this into terms western scientists could understand.

Don't let the fact that very very few people have heard about this theory fool you. It was completely unknown to us for decades, largely because everything was in German and Heim himself was a recluse.

If I were handless, mostly deaf, and blind (as it is my understanding Heim in fact was), I'd be reclusive, too.

The theory has already proven out as far as the particle mass equations are concerned; this is ably demonstrated on the thread I linked to above. But some does not equal all, and a great deal of testing has yet to be done.

Incidentally, the energies we are talking about here are within the capability of the Z machine at Sandia; there was talk of using that to test some aspect of the theory. I think it was determined that access to that isn't in fact necessary to test the theory.

Here's a short answer I got from one of the discussion's participants, a one Will314159:

Of course HT is a geometrical theory. Anything incorporating General Relativity is geometrodynamical. That is uses geometry to explain dynamics. Matter bends spacetime. And matter takes its instructions on how to move from curved spacetime. That is the essence of GR.

The quickest way to learn about HT besides reading all the backpages of this forum is to go to http://en.wikipedia.org/wiki/Heim_theory and peruse the links.

the articles by lludwiger and the links to protosimplex are outstanding.

The entire thread is informative, and populated by people far brighter than I. We'll see if anything comes of it....

[mccoyn]

14. I used to think so.

Until I read about the Fermi Paradox. The general idea is that if alien intelligence is common and we have seen no evidence of it on earth then there must be some immutable barrier seperating races. That is most likly the energy and speed problems we already know about.

I expect we will send probes and possibly some humans to nearby stars, but we will never colonize the galaxy. I hope we will at least communicate with aliens, but I expect we must learn how to listen to them ourselves.

[qazplm]

16. kind of incompatible statements there...

if you believe that we can send humans to nearby stars, then why wouldnt you believe that those humans could go on to nearby stars, and then so and so on until the entire galaxy was filled?

Mathematically it would take IIRC less than a billion years.

Certainly doable.

Over the long term, almost a guarantee.

[mccoyn]

18. Just because we can visit a nearby star doesn't mean we can colonize it.

It may be that none of the stars nearby have planets with the right conditions to support a sustainable colony. While we can get to them in a lifetime, we can't setup a colony to be the stepping off point for the next star. My belief is that if it were possible then aliens would have done it already.

[Occulus]

47. Why do you need a planet?

Why not build a Dyson sphere- or even something like what's in the game Halo?

Why not just live on ships in space? Aside from the physical problems it would pose to us- but then, assuming we could get to a far-flung star, we can also assume we can engineer ourselves. Think microgravity adaptations here- legs like stubs, arms of an Olympic swimmer (pulling oneself around a ship might do that)...

We could live underground on a planet with the 'right' mass (and therefore gravity), given we can grow things there. Life might not be there when we get there, but who's to say we can't put it there?

I think we need to colonize the Moon and Mars to answer some of these questions. I also think, eventually, we will have no choice but to expand or start dying out.

[Ediacara]

27. I don't think the Fermi Paradox is a problem WRT intersteller travel

I think the "solution" is that no species or civilization can live forever. The average "species lifetime" for animals on Earth is between 100,000 and 30 million years. Mammalian species are at the low end lasting only about 1-2 million years. Even if we take the high end, that leaves any inteligent spacefaring civilization only about 0.2% of the age of the universe to be extant. Of course, the likelihood of spacefaring civs would be close to 0 at the beginning of the universe and is now obviously at 100%, but it still leaves us with an almost non-existant slice of time to run into another spacefaring civilization. If humans are in space exploring the galaxy for a mind-boggling 100,000 years, we still need to run into another spacefaring civ that happened to evolve and become spacefaring at the very same slice of time amounting to 0.0008% of the age of the universe. Even if there is life on some planet around every star in the galaxy, and each of those planets evolves inteligent spacefaring life, that leaves us very little chance of running into someone else nearby.

[htuttle]

29. Well, as far as I'm concerned, if there's no one next door, it's OURS!

It's the Biospherical Imperative. How else is our own biosphere going to reproduce itself, if not by our efforts? Do we really have anything better to do as a species?

Best case scenario for our species: (cue porno sound track -- boom chuka wuka, boom chuka wuka) We are intersteller sperm, searching out fertile planets in the PRIME of life to impregnate with the FRUITS of our DNA..."Come here, baby. Your oceans are SO blue...."

:D

[lumberjack_jeff]

38. They all got raptured away.

... so we get their stuff. ;)

[Odin2005]

31. I disagree

IMO in space-faring civilizations are virtually immortal, their high level of technology releases them from the things that cause non-sentient species to go extinct. I think the problem is that civilizations that we find as we explore the universe will be far more advanced then us because the chance of 2 civilizations originating at the same time is almost 0, so thier technology is probably so advanced that we can't see it for what it is.

[Ediacara]

32. I don't think it's inevitable for spacefarers to become immortal

but then again, will an immortal species of god-like creatures really tool around in spaceships looking at biological curiosities? I am still of the opinion that any window of space-faring explorers will be prohibitively short compared to the age of the universe.

Then again, there are those that claim that Earth has already made first contact with many species of spacefaring aliens. Although I am skeptical, I am not dismissive of this claim.

[lumberjack_jeff]

37. If alien intelligence was common

the electromagnetic spectrum would be a cacophony of alien "I love Lucy" reruns.

There's been no sign of aliens because they are, if not nonexistent, at least exceedingly rare.

If any of the variables in the Sagan equation are zero, then the answer is zero.

[AlienGirl]

42. You can get the Drake equation to come out to 0, but what about 1?

Can you solve the Drake equation to make N=1?

N = R* fp ne fl fi fc fL

where:

N is the number of civilizations in our galaxy with which we might expect to be able to communicate at any given time
and

R* is the rate of star formation in our galaxy
fp is the fraction of those stars that have planets
ne is average number of planets that can potentially support life per star that has planets
fl is the fraction of the above that actually go on to develop life
fi is the fraction of the above that actually go on to develop intelligent life
fc is the fraction of the above that are willing and able to communicate
L is the expected lifetime of such a civilization

What numbers can you plug in to yield N=1?

Tucker

[htuttle]

45. L=200

...or less.

[TechBear_Seattle]

19. I've been working on that problem, as a matter of fact

When I get my first science fiction novel published, you will find out how I solved it. :hi:

[anarch]

20. can we have a hint?

Is it FTL travel? Wormholes? Suspended animation?

[TechBear_Seattle]

22. None of the above, actually

I create a very thin shell of abnormal spacetime around a volume of normal spacetime. Since this volume has no relation to the outside, there are (almost) no relativistic effects (time seems to travel a bit differently in the smaller volume, but you need to be on a long voyage and have an extremely accurate clock to note the difference.) And since the shell around this volume has a different structure than the universe it is travelling through, it is not bound by niggling details like the speed of light. There is enough "drag," though, that even short interstellar trips can be several days; it takes three weeks to get to our nearest extra-solar colony (one of only three; sufficiently earth-like planets are pretty rare.) That is three weeks regardless of whether you are inside or outside that shell.

Oh, and because of the quantum chance of matter slamming through the shell rather than sliding around it, these ships operate outside the heliopause and "up wind" of the stars they are visiting; the trip just from Earth to Sol Station can take anywhere from two to six weeks. Odd things happen to matter when the color of quarks takes on pastel hues. All in all, a passenger going from Earth to Aurora (the nearest colony, named specifically for the first Spacer world in Asimov's universe) will take two to three months from stepping off of one planet and onto the other. The time is almost seven months to reach the most distant colony, Wu Wei.

For a more detailed answer, you will have to wait until my first book is published. I hope to start shopping for a publisher soon. :hi:

[Occulus]

46. That sounds like the Alcubierre warp drive

This, from http://en.wikipedia.org/wiki/Alcubierre_drive">the Wiki on the subject (I know, I know; this is, however, consistent with what I've previously learned about the subject):

In 1994, the Mexican physicist Miguel Alcubierre proposed in the Journal of Classical and Quantum Gravity a method of stretching space in a wave which would in theory cause the fabric of space ahead of a spacecraft to contract and the space behind it to expand. The ship would ride this wave inside a region known as a warp bubble of flat space. Since the ship is not moving within this bubble, but carried along as the region itself moves, conventional relativistic effects do not apply. However, there are no known methods to induce such a wave or to leave it once it starts, so the Alcubierre drive remains a theoretical concept at this time.

Here's the accompanying diagram:



By the way- as I understood it, there's no 'drag' between the inner portion of the bubble and the normal space surrounding it; since it's a region of spacetime itself that is moving, with a ship enclosed in the 'bubble', normal relativistic constraints do not apply (how fast can space itself move?). Similarly, no object would be able to enter the bubble once it's formed, eliminating the need for protection from particles or other matter slamming into the bubble (or vice-versa). Depending upon how large the contraction and expansion of spacetime is, your voyages could in fact be arbitrarily short.

You could even call your mechanism 'Alcubierre Drive'; I'm not aware of any science fiction novels that have embraced his method. Then again, I've by no means read all the science fiction that there is.

[TechBear_Seattle]

57. I was thinking of this; didn't know it had a name

I had something like this in mind the alien race we encounter, although in a way that did lead to relativistic effects.

[YankeyMCC]

21. Not the way most people imagine it and not for a VERY

long time.

In the distant future perhaps there will be some kind of 'generation ship' or more likely some kind of robotic system that carries genetic material a sort of 'seed' we might send out to plant a terrestrial type ecology if it finds a suitable planetary surface.

It's just not economical (and I mean that in terms of real resources not profit making) to send people unless there is some shattering new discovery in physics which I suppose is always possible.

And there's plenty to keep us busy in the solar system for a very long time. :)

But this in No Way will this stop me from enjoying Science Fiction that includes travel to the stars :)

[HiFructosePronSyrup]

23. Nope.

I'm weighing the technological difficulty in reaching the stars with the technicological difficulty in blowing ourselves up before we achieve the former.

My magic 8-ball says the outlook doesn't look too good.

[anarch]

24. yeah, that's kind of the real key question, isn't it?

Whether our species can survive our tendency toward self-destruction for long enough to allow our drive to explore to overcome all the difficulties involved. Hate to say it, but I'd have to agree that it really doesn't look too good...I mean, we already have a wide variety of effective ways to kill all of humanity, but no viable way to leave the solar system, so there you have it.

[Fox Mulder]

25. I think one day we will...

but that won't happen in my lifetime, my kid's lifetime, or my grandchildren's lifetime.

[Phoonzang]

28. Yes, most likely.

Interstellar travel may seem impossible or impractical at best, but so do many things until there's some world-shaking breakthrough.

Edit: Yes we'll travel the stars unless we manage to do ourselves in.

[Lydia Leftcoast]

30. Not with our current technology

Recent issues of Scientific American have even cast doubt on human trips to Mars until problems of bone loss and exposure to space radiation are solved. That's a voyage that would take a couple of months with our technology.

I did a little math a while back, and, as mentioned above, the neighborhood of Alpha Centauri would be reachable in four years IF the space ship were traveling at the speed of light, which works out to about 6 million miles an hour. And we don't even know if there are any planets of any kind around Alpha Centauri (unless there have been some new developments in astronomy that I've missed).

So for the time being, we'd better make the best of this planet and not count on the "out" of interplanetary exploration anytime soon.

Besides, I'm sure our species would be just as capable of wrecking other planets as it has been of wrecking Earth.

[EST]

36. Ummmm...

Lessee here...
186,000, mile per second=light speed, or universal speed limit, if you prefer.

X60=11,160,000 miles per minute

X60=669,600,000 miles per hour

That's Six hundred sixty nine million, six hundred thousand miles per hour, rather than six million miles per hour.

Your speed is too low by two orders of magnitude.

At any speed we can conceive of for complex material objects, it's gonna take a hundred thousand years or more to reach alpha c.
An object falling toward the sun and accelerating all the way is still only moving in the neighborhood of fifty miles per second and even at 1% of the speed of light, 1860 miles per second, thirty seven times the speed of the in-falling object, the trip to Alpha Centauri will take four hundred years...

[Lydia Leftcoast]

53. Oh no! It's worse than I thought!

:wow:

(Thanks for the correction. I've always been dysmathic.)

[GAspnes]

33. In human form?

I doubt it. Radiation, travel time and food/water sources are formidable problems.

However, just before I die I plan to have my consciousness and the entire knowledge of the human race (especially including all the Travis McGee novels) downloaded into a hardened computer about the size of a shoebox (a very likely possibility in 40 to 50 years, assuming I quit smoking) and launched at some leisurely speed like 5.376e-6 C towards the Galactic center.

I'll drift along, going to 'sleep' for thousands of years at a time, wake up, experience steak dinners and fine concerts, look around, check the recordings from Earth and the sensors, send emails, and arrive, sooner or later, to take a ride on the Galactic Black Hole rollercoaster.

[hunter]

43. That's somewhere around my opinion.

I think Vernor Vinge has got it right with his Singularity. Synthetic intelligences beyond our understanding will be out exploring the universe while we, if we are lucky, will be at home occupying a comfortable ecological niche.

We'll have more in common with whales, dolphins, chimps and gorillas than we do with the space faring civilization we created.

[Vincardog]

34. No we will kill ourselves off first. We are gone in the next mass

extinction. We can not complain as we will be the lever that causes it.

[OldSiouxWarrior]

35. No.

Given the size of the galaxy, it is unreasonable to think that we are the first species to become technologically advanced. Othere species on other systems have had to look at this problems first. And they couldn't solve it. If they had, they would have gotten here before we evolved, and they would be here and we wouldn't.

But we are here, therefore, they didn't get here. Therefore they couldn't. And we can't either.

[Spearman87]

40. That depends on how frequently technologically

advanced civilizations come into existence. Optimists like Carl Sagan might have you believe it happens with great regularity. But I know that in Peter Ward’s “Rare Earth”, he theorized that the probable number of such civilizations might actually be much lower than previously assumed by the optimists. I don’t recall him giving an actual number, though in one interview I got the sense he thought there might be less than 10, currently.

There’s also the question of the temperament and personality of a species, as it affects their desire for space travel. We have the strong desire, but that’s not a given for an advanced species. And if they do have the desire, do they necessarily want to attempt full-blown missions all over the place, including here? Or might they be satisfied with more localized or regional explorations?

Personally, I think it’s not possible to develop any kind of reliable interstellar flight for large-scale ships. There are too many technical barriers and physical obstacles in space. Smaller unmanned probes will probably be feasible. So in that sense I actually agree with your conclusion that it can’t be done. I just don’t think we have the level of knowledge needed to talk about the probabilities involved, either of developing the technologies or of estimating how many species may have tried to do so. There are too many unknown values in any kind of Drake-type equation you can come up with. We simply don’t know the probability of civilizations advancing to at least our stage of development or beyond. There could currently be 18 in the galaxy. There could currently be one. I wonder what kind of civilization, if any, would have evolved here without the chance asteroid impact 65 million years ago, and thus repiles remaining as the dominant form of animal life. Mammals might never have gained the strong foothold they did in the reptiles absense. One outcome might have been that no intelligent species came to the fore. Another would be that a strain of reptiles developed where the evolutionary value of high intelligence came to the fore, just as happened with mammals in the primate line. Who knows.....and what would that have led to? Mammals and Reptiles are so vastly different in temperament.

[rman]

41. Or they did get here and we don't know about it.

:shrug: it's a possibility

[anarch]

70. or they did get here and we are them

Just something I like to kick around in my head now and then...the fossil record and genetic links to our pre-human ancestors notwithstanding.

[lumberjack_jeff]

39. It will eventually be possible to *explore* other stars...

... but only by better understanding the subatomic realms, and exploiting the invisible dimensions to explore the macroscopic ones.

"Travel"? Unfortunately, no.

[TheBaldyMan]

48. IMO a massive waste of resources. Deep space exploration can be done far

better and cheaper by remote probes like the Voyager programme. Manned space flight should be limited to low Earth orbit, not even the Moon is worth the bother IMHO.

If the human race wants to push back boundaries there are more than enough challenges in the bottom few miles of our own atmosphere.

[Occulus]

49. I hate how that point of view completely misses the point

Expand or die. It's very, very simple. Either we will move beyond this planet, or we will exhaust all our resources and die out.

It all comes down to heat in the end (resources = heat), and there's a finite amount of it. We may be able to extend the usefulness of those resources for, oh, another few centuries or so (barring some physics 'magic' making our current methods obsolete), but eventually we will have to expand or die.

Consider this:

The US population is at 300 million (roughly). The growth rate of the US population (and the US alone, not counting the rest of the world) is (arbitrarily) 0.9%. Now, given these numbers and a constant, steady growth rate, what do you think happens a century down the line? And that's just the US population, not even bothering with the rest of the world.

Basically, those who say we need to stay here and not expand beyond Earth are dooming everyone downstream. Remember Polynesia. Recall Easter Island. We must expand beyond Earth, because eventually, we will have no choice in the matter. We need to start doing it now, while we're fat and soft and have plenty of surplus resources with which to build colonies and get there- wherever "there" is.

The only way you can stay on Earth and not expand further is if you accept death in the billions- a general depopulation much, much larger and more extensive than any genocide ever perpetrated by any nation, ever. We must accept that the population will shrink as finite resources are consumed year by year, because that is what must happen in order to stay on this one lonely rock. Wars will become more and more savage as the weapons used to fight them run out of ammunition (with too few resources to make more) and people are forced to bash each other's heads in with rocks and clubs. Eventually, if all resources are used up, Earth would become uninhabitable... or humanity would become extinct.

I can't think of anyone who would be comfortable with that.

[TheBaldyMan]

51. It's a matter of energy : nuclear/chemical -> kinetic -> potential

work out how much energy you need to accelerate 1kg from the earth's surface to low-earth-orbit (LEO) then how much more energy it would need to accelerate to escape the sun's gravitic well. Now multiply that by 1000, then multiply that by the number of metric tonnes you would for a massive multiple occupancy ship.

Even if you try and use asteroids or moon rock as raw material you would still have to extract raw materials and then process them into finished products.

Compare those costs in time, effort and money to a problem that affects us all and is already passing a critical stage - climate change. We need to start thinking in different terms to exploration in space and start thinking about explorations in co-operation, problem-solving and resource distribution and usage today.

Our 'inner space' needs to be explored and conquered just to survive the next few centuries. Th sun won't go nova for a few billion years yet. The problem of climate-change, waste, pollution etc. needs to be resolved today. If we don't solve these far more pressing problems none of us or our descendants will be going anywhere

Easter Islanders depleted there resources but they didn't have the predictive tools that we possess, there is no problem that can't be solved when the political will is there. Think of how much the Bush administration could have done with the money that has been wasted in the "Global War on Terrorism". Think of how much more devastating the aftermath of Katrina has been because of political indifference.

Now apply those priciples to the problem facing our planet and everything that lives on it. It is already too late to think of escaping, we need to start clearing our own crap up and living sustainably. We need to halt, then reverse, the effect we have had on global ecosystems.

You are presenting a false dichotomy - rather than between expand or die, there are a great many ways we can take and quite a few of them have a positive outcome. The sun will provide an energy input for our global ecosystem for billions of years, just as it has done for billions of years already. We need to live within our means, everybody can be fed, housed, clothed, educated and live a valuable and productive life as will our children. We just have to stop being so damnably greedy.

[Spearman87]

52. A little science nugget unrelated to your central premise

But still interesting. This planet will become lifeless and uninhabitable long before the 5 billion years or so until the sun destroys it. The sun has been growing steadily hotter and brighter since its birth, and will be hot enough that the earth's oceans will have boiled away 500 million years from. That calculation had been done by one of the guest scientists on NPR's "Science Friday" on a show I heard a few years back.

[Occulus]

55. In 500 million years' time, we will have either died out, or

become so vastly different from what we are today due to our changing environment that we would be unrecognisable as human to us today.

What might a microgravity-adapted human look like? What might a high-radiation-adapted human look like? This assumes we survive that long and have to leave Earth (and assuming we haven't already done so).

Perhaps those people downstream will have a completely different solution from what we're discussing here. Maybe they'll find a way to download their minds into a piece of technology, and launch the whole civilization into space in a computer the size of a shoebox. Maybe they'll find a way to transcend their physical form in some other way. Maybe, sometime in the future, we'll find out how to make c irrelevant to space travel, and simply blink across the galaxy and the rest of the universe with no awareness between materialization.

Or maybe we'll invent advanced nanotechnoloy and be able to mold objects from the dust beneath our feet. Maybe we'll learn enough about genetics that we'll be able to use nanotech to create living beings, new species out of raw materials, which we can genetically program to do a specific task, like cleaning up radioactive waste and breaking it down into useful raw materials. My resource death scenario is far downstream from us, but such technology would postpone that fate.

I think I should note, there isn't any 'right' solution to this problem. Very likely, the 'solution' will be simply a string of stopgap measures until we get really smart and break or circumvent the light barrier. But I do think we ought to be considering this problem now, while we're fat and lazy and live in a time and land of relative plenty. The clock is ticking, and when the alarm goes off, it will be far too late to do anything about The End.

[Occulus]

54. If you're talking about solving problems on a global scale,

I think we should be putting lots and lots of effort into nanotech research.

Which, by the way, is being done.

There's a thread here in the science forum I'm sure you've seen- I think it's titled "Mmmmmmmm... nanotech", and it links to a video which describes what a true nanofactory might look like, and how it might function. The very fact this is being seriously discussed- seriously enough that somebody or several somebodies went to the trouble of modeling it, setting up animation constraints and kinematics, and rendering out a video (which takes a great deal of time)- is enough to make me seriously consider the ramifications of such technology. Sufficiently advanced nanotechnology could enable us to turn this planet into a paradise, given enough time for the technology to mature. In any case, this technology will be developed; it's only a matter of time.

I must quibble with your first paragraph: no ship of any size to accommodate a viable colony would be assembled here on Earth and then blasted into orbit as a single unit. It would of necessity be built in space (for the very reasons you gave), and we could mine the asteroid belt to get to the raw materials we would need to build it. This itself could easily be done by robotic craft; such a device could tow the rock into orbit and mine it at the same time. If we did it right, by the time it got here, we would have the materials we need, ready to process. Such drones need not be large, either; they could be very small, but numerous.

Could we tow a rock into orbit by having several robotic tugs tack into the solar wind? I think so. I think we already have the technology necessary for this to be done, and I think it is only a matter of will. To do so, even once, if we picked the right target, would irrevocably alter world economics, and that's only a beginning. We just don't know what's out there.

The choices I proposed- expand, or die out- do not represent a false dichotomy; in time, all resources will be exhausted, or we will have finished ourselves off. We could bring those resources to us using the methods I gave above, but eventually, if we survive long enough, they'll be mined out and we'll be back to square one. We don't even really know the composition of all the rocks out there, but one thing is certain: even that is a finite resource, despite the massive, inconceivable wealth of raw materials in the asteroid belt.

We can't, as a species, learn to live within our means without some external motivator. I don't know what form that would take- global economic catastrophe, perhaps; maybe a plague? Certainly, mass famine has not motivated us to live within our means; nor has lack of water, dwindling petroleum resources, a changing climate, and on and on. We fight wars over these things. I think this may be because biological greed- the need to have 'enough' food, water, and shelter- drives us to obtain more than we need at the moment, hoarding away for future use. Animals (such as squirrels) do this, and we humans are, though we may deny it until our dying day, animals.

The sun will provide energy to our planet until it dies, but that energy will be wasted on a dead planet if something doesn't change. The sun will eventually set on humanity; we need a plan to avert that end, and staying here and consuming less is a stopgap measure at best. Given enough time, the 'heat death' will come to us, in the form of resource depletion. We have three choices, actually: to do as we currently are, to do as you suggest, and live within our means, or to expand. We could do a combination of all three, and probably will.

Unfortunately, all humans will never, all together, live within our means; some of us will always deny resources to others to their own benefit. As you said, we're too greedy, and that will be our undoing if something is not done. Political will is only part of it: think about how many people in this old world have more cash on hand than they will ever realistically be able to spend for themselves, and then think on how much good could be done with all that cash. You're right, of course, to reference the war in Iraq vs. the response to Katrina; our priorities are terminally FUBARed. The very, very wealthy sit on their dough, just so it can make more dough for them and remarkably few others. The rich dole out dirt carrots to dust bunnies, and call it 'charity'. THEY could do more than you or I ever will, yet they don't.

My only answer is to get off this rock and go get resources, or bring those resources to us. Some of us need to fork off and establish humanity somewhere else, or commit to ensuring we don't use this planet up. I don't see any real reason why we can't do both: conserve our resources, and bring in more from Out There. Doing both would enable us to have enough breathing room to go and establish those colonies on the Moon and Mars, and admit it- being in on all this would be a hell of an adventure, even if you never left Terra Firma at all.

The stars, for the moment, are firmly out of reach, but there's no reason we can't exploit our own system, and there's no technological reason we can't start doing so today. Nothing says we can't do both what I'm suggesting and what you suggest. As you said, we only lack the will to do so.

[bananas]

56. Those calculations have been done over and over and over

There is plenty of energy available to get into space,
and even more energy once we're out there.
People have been doing these calculations for decades,
it's not even a matter of controversy anymore: http://en.wikipedia.org/wiki/Kardashev_scale

The next generation of deep-space probes will be solar powered,
something the luddites considered impossible just a few years ago:
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=228x23960

[TheBaldyMan]

59. I dispute utterly the nonsensical Kardashev scale - it is NOT beyond

doubt by any means. There are a few things in that article that make me wonder about the inevitable march to the stars. If the human race is closer to a sustained fusion reactor than we were in the 60s then it's news to me. Space elevators are not inevitable, everything in that article is as speculative as the function for the probability of life in the galaxy (Drake's Equation). There are a lot of unknowns, don't confuse speculation as fact.

I'd like to think that I am not a luddite, I'd prefer to think I retain a healthy skepticism and try to interpret these schemes as coldly and objectively as possible.

Indeed there are an awful lot of calculations that have been repeated and always come out with the same answer, including the calculation about the amount of energy it would take to accelerate 1 kg out of the Sun's gravitational potential well. That is real physics and is the basis of at least one question in every introductory Physics textbook.

[Occulus]

60. Well, we're working- hard- on nanotechnology

And that's what it'll take to make the idea of the space elevator viable. Conventional materials simply will not cut it.

As for fusion, we'll figure that out. The Sun does it. It's within our understanding, and eventually, it'll happen.

Were you talking about "cold fusion"? Because, as I understand it, that is a pipe dream. But controlled fusion itself is a reality:

http://www.iter.org/a/index_use_2.htm

You left out the speed of that 1 kg object, by the way. It doesn't need to move very fast; all it needs to do is move. Use the solar wind. Use fusion reactors as engines. And so on.

Life elsewhere would be very nice; intelligent life elsewhere would be an enigma wrapped in a mystery wrapped in a puzzle. We wouldn't understand it as life if it bit us. But I'm less concerned about ETs than I am about our own survival.

We need to expand, or in the meantime gain resources that exist outside Earth. For all we know, there are elements here in our solar system that we've never conceived of- elements that could enable applications in physics we only dream about today. To say that the elements on the periodic table we all know and love are the only elements possible is the most colossal hubris and arrogance. The fact is, we don't know what's out there.

We owe it to ourselves and our humans downstream to go and look, personally, or with robots.

An aside: What would you say if we found an artifact of some sort, clearly artificial, in the asteroid belt, but no other signs of life of any kind? Such a discovery would all by itself be justification for serious space exploration.

Would you agree?

[TheBaldyMan]

62. work out the energy need to accelerate 1 kg out of the Sun's gravitational

influence (Solar escape velocity) then get back to me, here's a clue solar escape velocity is REALLY, REALLY fast. I'd prefer the answer in SI units (joules). I am not talking about cold-fusion, btw read your own link , the ITER project hasn't achieved a sustained fusion reaction. Hot plasma isn't fusion. In fact the degree of vacuum needed for this hasn't been achieved yet on the earths surface and remains a degree of magnitude away.

I have studied applied physics and astrophysics at degree level and remain unconvinced by the speculation about what is achievable. As Montgomery Scott always said : "You cannae break the laws of Physics, Cap'n. "

The speculative stuff should be posted in the Sci-Fi section, not in the science forum IMHO.

[Occulus]

65. Heim theory would explode your head, I bet

In fact, I'll presume you've never heard of it, I'll assume you'll poo-poo it, and I think you'll say there's nothing to it.

Why? Because you're a naysayer. You seem to take delight in telling people things can't be done, things aren't there yet, etc... without any encouragement, actual advice (other than "it's a waste of time"), and so on.

In other words, you are "old" and in the way.

I'm DONE with you, and I'm putting you on ignore, not out of spite, but because YOU do not deserve to be heard by the likes of ME.

Bye!

[bananas]

61. Obviously the Pioneer and Voyager missions are NASA hoaxes!

It just takes too much energy to accelerate 1kg out of the solar system!

These are different questions - whether the raw energy is there vs whether we will be able to develop the technology and engineering to actually do these things.

[TheBaldyMan]

63. pls read my previous posts in this thread.

please enlighten me, where exactly did I claim voyager is a NASA hoax or there wasn't enough energy to do that?

Don't put words in my mouth, if you're going to try at least have the courtesy to read my posts first.

btw I know the answer to that particular question, I am still waiting for any answer to that question let alone the right answer.

[qazplm]

64. if you concede that today

we can move something the size of Voyager out of the solar system, then how in heaven's name do you not believe in 10,000 years we might not get a wee bit better at moving larger things farther and faster, including things big enough to fit some people?

Sooner or later we are going to figure out controlled fusion. We will also figure out how to create antimatter in appreciable amounts, and use it as another form of fuel.

And I am not 100 percent convinced that if we are still around 1 million or 10 million years from now that we wont figure out space warping.

But guess what, its going to take a LOT of tiny little steps to accomplish those vast dreams. And that means starting today. With little things. Manned flights to Mars. Experiments on controlled fusion. People thinking about ways of going FTL even as people like you deride them for doing so.

[Occulus]

66. People like him are very bad for science as a whole

I really wish such people would retire. Go cut lawns, or something.

Science needs imagination the way music needs instruments. That guy has nothing positive to contribute.

Now, let's talk about the possibility of the existence of gravitophotons. In other words, let's really piss him off!

:D

[TheBaldyMan]

67. pls read my posts, you will find your own answer there

Stop putting words in my mouth. RTFP (http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=228&topic_id=23509&mesg_id=24375">#48, http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=228&topic_id=23509&mesg_id=24378">#51 & http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=228&topic_id=23509&mesg_id=24415">#56) first, then criticise what I actually wrote.

[qazplm]

68. I AM criticizing what you actually wrote

you act as if people are advocating that we begin building a generational ship tomorrow.

We are saying that one day in the not so far future we WILL be sending people to live for some period of time on other parts of our own solar system, and in the farther future yes we will be going outside of it, and we NEED to because we are not guaranteed that this lifeboat we are currently on will always stay above water, EVEN if we every last person were the greenest of environmentally green.

And the fraction of our budget we spend on manned space exploration is not going to be the difference between global warming hell and environmentalist nirvana.

[TheBaldyMan]

69. read post #51

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=228&topic_id=23509&mesg_id=24378">post #51

if we don't sort out far more urgent problems first none of us are going anywhere.

[qazplm]

71. point me to one person

advocating that we stop everything we are doing, and begin building a generational starship.

When you find that person, let me know.

No one with any credibility is saying we do that. What they are saying, is that we DO need to begin to learn how to live in space, we need to continue manned exploration of space because it is ALWAYS going to be the case that someone says we have better things to do.

And the miniscule amount we spend on space research in total is not enough to make a bit of difference in ANY of the urgent problems we have here on Earth.

[Orsino]

58. No.

I'd like to believe that it could happen, but we seem too preoccupied with blowing each other up even to get out of low Earth orbit, much less figure out interstellar travel. I rather doubt that we'll reach the Moon again before a global ecological/economic collapse.