We should go to space because that’s where everything is. And by everthing, I mean everything. Remember how 0.999…9=1? Well, 0.999…9 of all matter in the universe isn’t on Earth. Our planet is so miniscule that statistically, it doesn’t even exist.
I don’t know how much you understand about engineering, but you seem to be basing your opinions upon modest developments of existing technolgies. Certainly, we’re not going to be flying the Shuttle (or the Orion/CEV) to Mars, and we’re not going be using chemical rockets to explore interplanetary space. There are extant or readily feasible technologies, like nuclear pulse propulsion (Project Orion) or the magnetoplasmadynamic thruster which would permit relatively rapid transit (on the order of weeks) to the asteroid belt or gas giants. We’re not going to do this next year, or even within the decade, but there is nothing fundmentally impossible about it, and indeed, once the technology is matured beyond the experimental stage, there’s every reason to believe that people and governments will want to do it.
Regarding the economics, it is certainly going to be cost-prohibitive, even with superior propusion technology, to ship large masses into orbit. (That “stupid space elevator” you so dismissively deride could reduce such costs to a reasonable amount, but material issues aside I doubt such a thing will be built in this century, or even the next. The engineering problems and natural hazards are daunting, to say the least.) Shipping stuff downhill, on the other hand, is dirt cheap, especially if you aren’t trying to get it there as quick as possible. Slowing an mineral-rich asteroid to an intercept course for an Earth orbit with low, constant thrust electrostatic motors would be cheap and easy, and such wealth from even a modest asteroid could dwarf what we can dig up on the planet. No one (except a few nutcases) is going to be concerned about strip-mining an asteroid, and many refinement processes would benefit from the almost perfect vacuum conditions of orbital space. This is particularly true for natural radioactives of which we have a limited supply and (baring developments in commercial fusion energy production) will be in increasing demand. The cost to get such operations in orbit is exhorbiant, but once you’ve paid the entrance fees and have the infrastructure the running costs should be quite profitable.
None of this takes any magic, any more than commerical air travel does (which would be just as miraculous to a 10th century monk as interplanetary spaceflight is to us.) We’re not going to be doing it in a shuttle with falling tiles–even advocates of that system admit that it is obsolescent and disappointing in performance, barely a first step (and then one that was more sideways than forward) into ready access to space. It will take a will to invest in the initial technological development infrastructure and take the necessary risks, and frankly it’s not clear how or by whom that will occur, but it is certainly plausible.
I’m somewhat doubtful, however, regarding plans to colonize the planets of this system; pipe dreams about terraforming Mars or Venus aside, there really isn’t any body that is habitable or likely to be made so, nor is there much of an advantage to living in warrens on Mars or the Moon. Materials are more easily accessed from space, where you don’t need to raise them out of a gravity well, and lacking the protection that the Earth’s strong magnetic field and thick blanket of atmosphere provide there’s little advantage to colonizing worlds. You might have scientific outposts on the Moon, Mars, Jovian and Saturnian satellites, but I can’t imagine any resource that would be cost effective to export from such stations. Orbital colonies seem more feasible to me, but there are obviously significant concerns and hazards, from radiation and meteroite damage to freefall and technical risks. I think these issues can be addressed and the hazards mitigated if not eliminated with time, but that’s going to be largely a trial-and-error process with an acceptance of a certain level of risk.
Talk of colonizing worlds in other star systems is, at this point, on par with space opera. There are reasons to believe that it’s possible to bypass or at least seriously bend the laws of physics to get from here to another system in less time that it takes light to travel, but there are also reasons to believe that, even if such methods are conceptually possible, we would not be able to exploit them for any useful purpose in reality. Generation ships and the like are feasible, I suppose…but why bother sending delicate bodies (prone to damage and disease) across the wastes of interstellar space when you will likely be able to build machines that do it much more efficinently and with less hazard? By the time we have the capability to do such things I sincerely doubt we (or our progency) will look anything like we do now. The one certainty is that we won’t be warping around in saucerous ships and colorful uniforms phasering knobby-headed bipedal aliens who quote Shakespeare as their own and have novel, anacronistic customs about melee combat.
Stranger
You don’t even need to go that far back. Got back to the Fifties in your hypothetical time machine and start talking about powerful digital computers the size of a paperback book or color televisions that you can tuck in your pocket and you’d be tossed in the asylum (or perhaps lobotimized) quick. The reason propulsion technology hasn’t advanced as far as, say, computers is because there has been little impetus to do so. Even the US space program has been essentially a hobby, with no firm plan or political will to develop technology for permanent habitation of space.
Freezing and thawing living mammalian tissue is about as far from reality as wormholes. There is no foreseeable way, other than somehow injecting an anti-freezing compound into every cell, to prevent damage at the cellular level from ice crystals. Maybe someday someone will figure out how to integrate such capability into the human body, but I wouldn’t bet the morgage payment on it.
By ram-jet I assume you are referring to a Bussard-type hydrogen collecting ramjet. While it’s an interesting concept, there are some serious technical problems with the idea that may make it complete infeasible (for one, you’re going to be generating a gignormous magnetic field, and there’s no conceivable way to shield the passengers or lifesystem from it). In any case, moving through the interstellar medium at a significant fraction of c is going to have significant hazards quite aside from the propulsion system, and a chance encounter with any solid body even as large as a grain of sand would be catastrophic. (There’s an Arthur C. Clarke novel (The Songs of Distant Earth?) where he has the spacecraft preceded by a shield made of interlocking pieces of frozen ice, and even then it’s only moving at a small fraction of c. Probably one of the more realistic portrayals of interstellar transport (aside from the freezing of bodies and the infinite power source) in science fiction.
Stranger
I will gladly yield any argument on science to you. I am glad I was at least recollecting cryogenics correctly. I had read some articles on various ramjet designs that had me pigeon hole them as feasible at least. If I can find any, I will submit them for your review.
Jim
I am not saying any of this is impossible and will NEVER happen. But I stand by my statement that it requires a ridiculously optimistic view of scientific progress to think we will have these abilities before they are needed. i.e. When we need to escape earth due to nuclear war or some global disaster we will have the ability to permanently leave earth and live in space.
Isn’t that what Hawking was saying? We might need to escape to space.
I think it is much more likely we will see the global catastrophe long before we are capable of permanently leaving this planet.
Which is likely to occur first? Planet-destroying nuclear war or colonization of space?
Stranger On A Train
I have no clue if you get Scientific America. It is where most of my Pop-Science knowledge comes from. The August Issue had this article, I have it at home, but hopefully you have access to it. Over the years there have been several others. I think March had a good article on a made for space Ramjet.
I have had the impression, you might be connected to JPL, is that accurate?
Jim
Come to think of it: given an infinite universe, it’s almost certain someone will colonize more than their home planet, and given current life expectancy and technology, it’s just as certain it won’t be us. Work on your karma, people, and better luck next time!
I seriously doubt that the technical challenges facing the biological sciences in coming up with a way to freeze and thaw a human are comparable to generating usable and stable wormholes. Regardless, cryogenics isn’t the only method of suspending animation…just the one you and others chose to focus on. There are other hybernation methods that have been successfully used on lower order mammals (such as mice) to suspend animation or slow down the metabolism to very low levels that could be adapted to use in humans…saving on supplies if nothing else.
I’d be willing to bet the morgage payment that some form of suspended animation for humans will be in use long before we figure out how to generate and sustain usable (and directable) stable wormholes.
-XT
No time for a comprehensive search, but here is a Wiki article on suspended animation, showing a few examples of successful tests. Oh, its not true cold sleep or true complete suspended animation…but the science is in its infancy here. Give it a few decades or a century or so and then come back (well, probably none of us :)) and we’ll see.
So, how far have they gotten on generating wormholes on the other side of the house?? 
-XT
Considering the Wiki article included the disclaimer:
You might want to spend some time later leading us to some cites. 
If you can somehow get humans to hibernate for 6 months out of 12, you still have all the associated problems of long travel only reduced by a factor of two.
I thought the idea of cryogenics at least was to reduce the time awake and consuming supplies by a much larger factor?
Jim
How is it stupid; somebody leave the gate open again?
Sure thing…here is an article on the BBC about the Science article. That good enough?
I really don’t see why this is considered that far outside of the realm of possibility. It seems like the science is still in its infancy…but that its not completley science fiction either. Especially considering the vast strides we’ve made in bio-science in the last few decades. A lot of the stuff we are doing today would have been considered pretty far out there in, say, the 60’s or the 50’s…some of it would be considered magic or impossible.
Whats your point? Lets say that in 20 years thats as far as the sciences has gotten. Do you think that reducing everything needed supplies wise by a factor of 2 is trivial? Think of the weight savings alone…not to mention the lessening of the mental strain if travel is cut (to those on board) in half.
And thats only if we cut things in half (or run their metabolisms at half strength for the duration while they basically sleep)…that seems a modest enough advance to me. Couple that with better propulsion systems and at a minimum our entire solar system is in our reach.
The idea of cryogenics is to freeze a human and then at some future date revive him fully functional. I.E. complete suspended animation. There are other ways of achieving the same thing…or achieving lesser but still helpful results. Hibernation for instance. I don’t see anything that says that hibernation is beyond the realm of bio-science…and I see some indications that its already in its first baby steps on the road to doing this with humans. Its not here today, to be sure…but then a lot of the stuff that IS here today wasn’t here a decade ago…and some of it wasn’t available a year ago.
-XT
I don’t think humanity will ever leave the solar system (and I don’t think it particularly matters). It’s just remotely possible that something we make (perhaps an artificial intelligence) might visit another star, arriving in the very far future.
It would be nearer to possible if we could invent a reactionless drive system, teleportation, faster-than-light travel, free energy and some kind of force field technology (or even just some of those things), but they pretty much all require an extensive rewrite of our most fundamental understanding of physics - not that it couldn’t happen, but I think it’s unlikely in the absolute extreme.
The limitations that face the idea of interstellar travel aren’t like the limitations that appeared to face powered flight or other technological advances so far, because they’re limitations not of our ability, but limits that exist in the nature of the universe we inhabit. You can’t simply extrapolate past progress indefinitely into the future.
Nah, not evil. I don’t think you’re going to find that.
Now, stupid and shortsighted and willing to sell out the future for the sake of a slightly more comfortable present, absolutely.
-Joe
Why are any of those things REQUIRED for humanity to travel beyond our solar system? Those are all required only if you want to get there fast. If you don’t care how quickly you get to the destination, I don’t see why any of the things on your list are necessary to humanity leaving this solar system sometime in the future.
No, the limitations you are setting are artificial limitations based on your wish list of technologies necessary to get us beyond our solar system. There are other ways that, while difficult, scale nicely with what our ancestors needed to do to, say, cross the atlantic ocean for the first time or colonize the new world. We had to learn things like navigation, better ship construction and of course logistics support for both exploration and colonization. And we had to be willing to take risks. Ship building especially had to progress to the point where viable ocean going ships were available to cross the oceans of the world.
I don’t see why we can’t extrapolate, based on current technology levels, possible ways of solving the problem that are viable. We don’t need magic future FTL or wormhole technologies to get us to the stars…just the will and energy to do it.
-XT
I’m being hyperbolic of course, but no conceivable hibernation technology is going to allow people to be suspended for decades or centuries of interstellar travel. There could be some revolutionary breakthrough around the corner, but I don’t see anything indicating that.
I’m not sure what you mean by this. We’ll have the technology when all of the foundations for it are mature. We might find that we need the technology tomorrow (say, to stop an asteroid heading directly for Earth) and not have it, incomprehensible Michael Bay movies aside. We ought to be developing it now, as best we can. Technological progress tends to jump in leaps and bounds; for thousands of years we used the abacus to perform calculations; for the better part of two centuries we had mechanical calculators, and for about the last 35 years we’ve had commercially-available electronic computers which have advanced from simple, desk-sized computers able to handle about eight digits in simple arithmetic functions to computers the size of briefcase that can simulate complex fluid flow and make animations so detailed they’re almost indistinguishable from reality. “Ridiculously optimistic” is, in fact, the way much technology progresses, particularly when you puncture some scientific threshold.
Nope, I work on the commerical side of aerospace, making old ICBMs (and the occasional new rocket) fly satellite deployment and target missions. Occasionally I get to peek at new technologies, but for the most part, my job is making thirty-year-old solid motors and their support equipment do things that they were never intended to do. Great fun.
Stranger
I honestly think optimism is getting the better of people here. Can you broadly describe a viable plan for travelling to a star that is, say, twenty light years distant? How long will the journey take? What propulsion technology will be used? How much fuel will be required?
Its 1860 and you watch as a Union observation balloon rises up into the air. Spot question…could you conceive of a jet air craft going over the speed of sound? How about a rocket ship?
Its the turn of the century (1900) and you are going to one of the great colleges of medicine…could you conceive of anti-biotics that could save millions of lives? How about laser eye surgery? Heart or other organ transplants? Molecular biology? DNA sequencing?
I’ve showed you a few technologies that are in their infancies…and yet, you can’t conceive of technologies that COULD allow for suspension of animation for decades or centuries? Not even imagine them? What can I say…
-XT
In my more cynical moods, I suspect that we won’t have settlement of the solar system until the Earth has been so environmentally degraded that humanity is surviving inside self-sustaining habitats anyway. At which point moving to the Moon, Mars or the asteroids will no longer be less hospitable than staying on the Earth.
Sure I could…and I’d probably be as accurate as that guy watching a Union observation balloon rise up and attempting to describe to the skeptic trans-continential flight.
Technologies we’d need to cross, say, 20 light years. Well, we’d need some biological advances as I’ve said…something that could suspend animation for centuries and revive the passengers at the other end fully functional. Other than that, some fairly decent advances in propulsion systems. Maybe nuclear or fusion (so we’d need fusion obviously too :)). Something getting us in the ball park…say .1C. The trip would then take centuries, instead of thousands of years to accomplish. Barring the hibernation thing, I suppose we could use generation ships…self contained bio-ships where the crew basically lives normal lives but in transit to the target world/solar system. With some improvements in human longevity and those propulsion advances, its possible someday.
I’m not saying we would do this next year guys…or even in the time of my grandson’s grandson. I am saying we could START now but doing more in space…manned exploration and exploitation of our own solar system would be steps that COULD be done in our lifetimes as a first step. There are plenty of challenges right there to keep us busy solving them for the next few decades at least…the radiation problem for starters. But in the end, its about will power and desire to do this stuff…the rest is just engineering IMHO.
-XT