A perusal of old Popular Science/Mechanics back issues probably would make for
amusing reading of this sort…
Our technology seems to proceed in fits and starts-sudden breakthroughs followed
by decades of statis.
No, I’m not underestimating the distance OR the time required. You set the theoretical distance yourself at 20 light years (about 200 trillion kilometers IIRC). At .1C that works out to about 200 years I think (though it would be significantly longer as you’d have to accelerate positively to get up to cruising speed then accelerate negatively to slow down sufficiently to orbit the target planet)…right? At .5C that would be 40 years…correct? I grasp both the concept of 200 (and 40 of course) years AND that of 200 trillion kilometers.
Is it no theoretically possible that we will come up with a propulsion system that can go .1C? I know of no show stoppers, as I said in the part you are quoting from me…though I conceeded then and now that its not within our current capabilities and we have only the most nebulous idea on how it would/could be done. Can we extend human life 200+ years, or suspend that life for that duration? Stranger says no, but I know of no physical law precluding it. He may be right and we never find a way to do it…but then, we may find the key piece next week too that leads us down the road to the solution. Based on the current research being done and how science in general and the bio-sciences specifically is currently progressing I’m betting we WILL find the answers to those problems…maybe not in my life time (almost surely not), but perhaps in my grand kids lifetimes.
Of course, were this the 50’s I’d be the guy betting we’d have flying cars some day, while many of the rest of you would be saying that all the major discoveries have already been made and science would just be refinement from here on out.
-XT
We have had working flying cars since the 1940’s. However, building something is only a piece of the innovation puzzle. Real-life people have to adopt it and be able to work with it for it to be viable and they aren’t and they can’t work with the way people live now (in the most basic sense).
Nobody is saying that science is down to refinement. I am certainly not saying that. I am saying that a prediction, other than the obvious and imminent, about one particular type of revolutionary technology is a fool’s game and can’t be done with any accuracy. The number of specific dependencies and predictions interstellar space travel requires to work at all is staggering and even one theoretical failure could cause the whole thing to be a non-starter like it has been so far.
I pointed out one obvious yet very serious theoretical problem that no one here can address. Space craft travelling at any significant fraction of the speed of light will get destroyed as soon as the hit the first flake of anything. That isn’t an engineering problem I believe. You would have to detect such things and either avoid them or somehow shield against them even more than the spacecraft itself and the energy we would need to do that is mind boggling even if there was hope for some dreamland mechanism.
The August article in Scientific America was on Scramjet to get to orbit. Not what I was thinking of.
The July 2006 article in New Scientist is on the developement of a new Ion Engine which should improve speeds within the Solar System and might be used to get us to Mars if we do not abandon this project when Bush leaves office. Not likely to ever lead to intersteller travel.
This is a prior article on Ion engines.
Of course there is the classic Bussard ramjet, Wiki has a decent article on it and its limitations.
I am going to wave a white flag. Without a digital subscription, I will never find what I *think * I was looking for. Maybe I will break down and give myself a digital Subscription.
Jim
Sorry…it was a joke based on a quote from someone my brain is currently too fried to remember saying that there were no new discoveries in science to be made. I’m not sure if the quote was from the turn of the last century or in the 50’s sometime…can’t recall now. The joke was that while I’m being overly optimistic, some of you guys are really going to great lengths to be pessimistic too. IMHO anyway. Its usually the result of these types of threads in my experience.
For anything large obviously the solution would be to avoid it. For smaller particles, yes…it could be a problem if you couldn’t detect them. Shields would be the obvious solution, if they could be made light and strong enough of course. I suppose some type of force field is theoretically possible, but won’t even go there as that really IS way out. Its certainly one of the engineering problems that would have to be solved, no doubt. I am unsure its a complete show stopper though, that no possible solution is feasible.
To turn something thats often used in these debates around a bit, just because I (or maybe no one living today) knows the answer, doesn’t mean no answer exists. As I tried to point out in earlier examples, your average Joe moping about during the Civil War wouldn’t have a clue how to solve even the problem of traveling faster than the speed of sound…wouldn’t in fact even know there was a problem TOO solve. Even the top scientist of the day in good ole 1860 probably didn’t know a sound barrier existed wrt flight, and wouldn’t have a clue how to solve said problem. Yet in less than 100 years the problem was not only discovered but solved. Shields on a space craft going .1C? No idea how to MAKE such a beast or how to protect it…today. Probably no scientist on earth has a clear idea on either of those scores either. Doesn’t mean that a hundred years from now however that that (or other problems) will be discovered and solved…or not solved and other methods used.
Right now we are in a period of huge growth across the board in science and engineering. And not just in the US or in a few select countries either. One thing is for sure though…if we don’t try to explore, exploit and colonize space we will certainly never leave this rock. The journey of 200 trillion killometers starts with a single step and all that.
-XT
If you or I were to go on a mission to another star, we’d be dead within a half-century or a century. That is true. But it’s also true that if we stay right here on this rock, we’ll be dead in the same half-century or century. Why is the one considered somehow less acceptable than the other? It doesn’t matter if I live to see the end of the trip, any more than it matters that I probably won’t see whatever the year 2400 has in store for Earth.
And once you’ve accepted that point, the speed issue also becomes irrelevant. Once I’ve decided that it doesn’t matter if I reach other stars, does it matter if it’s my children or my great-great-grandchildren who do? Just go at whatever speed you need for your shielding to be adequate, and take as many generations as it takes.
The only real barrier, here, is developing an ecosystem which can run self-contained for long enough. And the only real barrier to such an ecosystem would be an adequate energy source. That energy source would probably have to be fusion, and I’ll concede that that’s an unknown time away. But regardless of whether we leave Earth or not, we’ll develop fusion anyway, or die trying.
If it can be done, it will be done. It may not be economical, practical or desirable now or in the near future but I don’t see how it could never happen. The largest currency in the world is human desire. We do alot of things… and I mean ALOT of things that are really not cost effective or easy but do them anyway because despite the costs we find other more intangible benefits. We also do things that turn out to in the long run be mistakes, but find other unforeseen benefits because they were accomplished… for example the Sutro tunnel for the Comstock lode. I have no doubt that technology will advance to ease some of the hurdles. Today the rate of progress in many disciplines have driven the cutting edge so far out that people are afraid to adopt some newer technology for fear that they are already obsolete. There are also cultural and political factors that may drive us to develop space. Governments and corporations may in the future find it’s more economical and politically expedient to deal with the known dangers and expenses of space than the unknown and increasingly global problems of corruption, terrorism, nationalism, NIMBYism and protectionism. Sure you can mine Sudan for uranium… but given the situation on the ground, perhaps asteroid B456C is looking more and more attractive. There is no way to tell, but I’m going to put my money on seeing our descendents stretch out and off this mudball someday.
No need to waive a white flag, Jim. It’s not (despite all indications) a contest. 
It’s entirely possible that somewhere down the road, someone will discover a way to make superluminal transit possible. Or perhaps we’ll build “generation ships” that sustain a whole ecosystem, as Chronos postulates. There are significant issues–mainly, the mass of fuel and/or propellant required to achieve a significant velocity–but these may be overcome, whether by a Bussard-type ramjet which solves the technical problems we identify today, or by other means. (Dr. Robert L. Forward presented a number of concepts utilizing a fixed propulsion source using lasers, masers, or other means to propel a craft through interstellar space.) Or maybe we’ll find the means to suspend life processes as xtisme advocates. But right now, given foreseeable technology, this isn’t a foreseeable possiblity. I find it more likely that, when the time and technology comes, we’ll send machine proxies–perhaps with the same cognitive capabilities we have–in our steed, at least initially. We might send banks of DNA (or some other encoding of genetic information) to be reproduced elsewhere. But all of this is highly speculative. (Force fields? That’s as much science fiction as wormholes and warp drives.)
Exploring our own system is readily within the realm of feasibility, and indeed, necessity in the long term. I doubt we’ll be moving the teeming masses offworld; more likely orbital colonies will grow and branch out, exceeding the caretaker population of the Earth. Or perhaps we’ll all be wiped out in some common disaster before that happens. (All the more reason to get offworld while we can.) I have to shrug with the thought of polluting space; the environment there is, by and large, far worse than anything we can do to it. Save for somehow demolishing whole moons or planets–well and beyond any capability we can currently concieve of–I daresay that we’ll scarcely leave a mark that will be seen in a millenia.
One thing is certain; linear extrapolation from the technology we have now (i.e. shuttles with their falling tiles and marginally efficient propulsion) is almost certainly vastly underestimating the capabilities of the future. By the same token, assuming that specific technologies (indefinite life extension, Bussard ramjets, et cetera) is unreliable at best. There’s a middle ground between mordant pessimism and unbridled optimism, but it’s a large and ill-defined field.
Stranger
I think we ought to.
The world is in a foul mood. I suspect the species was built for exploration and is suffering from being penned up. We need new lands, new science, new people to let our natural urges flow. We are at our best on the frontiers, intellectual, social or geographic.
Still the costs are huge, unimaginable. We have to develop travel in our system first. The mission to Mars is a start. That done, we can look for a place to go. Then we will need biological and social systems that will let our explorers get to where they are going OK.
Then we send them. For centuries the new world will be a net consumer of stuff. All we will get back will be some trinkets. But someday, we will have a second home, a place full of new ideas, new ways of looking at things. Then we can look to doing it again.
I’m not saying that all the discoveries have been made; it’s important (to me, at least) that you don’t misunderstand my point in that way.
I’m saying that certain discoveries have been made (including the speed of light, the immense distances involved) that make it look very much as if the fundamental nature of the universe is very severely stacked against interstellar human travel.
I’m an optimist. The technology that will lead us to the stars is out there somewhere, we just have to find it. People are smart. We’ll figure it out.
Heck, I’m still trying to wrap my head around the concept of radio waves. You mean these two pieces of metal with electricity flowing through them can actually talk to each other? Through walls? And the fact that the vast majority of matter is just empty space within the electron cloud! Wowzers!
There are probably things out there that make as little sense to us as radio waves would to Julius Caesar.
My friend, stupid and shortsighted and willing to sell out the future for the sake of a slightly more comfortable present are some of the most common forms of Evil.
Yeah, but then to extend that only a little… why does it matter if nobody reaches other stars?
The idea and the hope of a generation ships would be to get humanity out to a new planets. As **Chronos ** stated and you quoted, be it kids, grandkids or 7 generations done the line. Just get them out there. There will be no shortage of excellent volunteers in my opinion to draw from.
Stranger On A Train, I know it is not a contest. I just get bugged at myself when I attempt to recall things from memory and I cannot back it up. Now I do not know if I jumbled the details in my head or if I just cannot find the source. For all I know, I was watching some pop-science show and somehow indexed the information in my mind as an article from the respectable Scientific America. I really might have to breakdown and get the digital subscription, I already enjoy the magazine immensely, and having the online full digital archive would be great. I just fear I would under utilize it.
Jim
That’s ‘how’ - I asked ‘why?’. Seriously - why bother? Why does it matter whether the human race goes extinct at some point in the future?
If you have to ask that question, then I do not believe we think remotely the same. That really does make it seem like you would have asked the same questions of Columbus and Hudson and Magellan or the colonists that embarked for Roanoke and Plymouth.
Do you think so little of the human race that you would not like to take a chance of sending some of our smartest, brightest and most creative out to the stars somewhere in the future?
I am not advocating we start this project in my lifetime. I hope we can at least increase our presence in space via a space elevator, scramjets or efficient Ion drives in my lifetime. A manned space station doing advance research and plans to explore that planet and asteroids at least by superior probes would be a good start.
Jim
No, I’m not sure it’s the same as that, perhaps because people exploring/colonising other parts of the planet have the possibility of returning, reporting back, communicating and trading materials and ideas with those who remained at home.
Does it have to be that I ‘think so little’ of the human race? Even if I do, does it matter?
Things begin, exist and eventually (and inevitably) end - that’s not a bad or evil thing, it’s just a thing.
There is a vast gap between our viewpoints. I think we should agree to disagree as neither of us can prove we are right. This is strictly a matter of our opinions. I am not saying your viewpoint is wrong or illogical, I am simply saying that there appears to be little or no common ground between my viewpoint and yours.
Jim
OK, If you like… it also doesn’t matter either if we disagree, in the long run.
A few people have compared this to proposing jet air travel to a person in the 1800s. That seriously understates the scale.
A better analogy would be to imagine going back in time to a stone age village 20,000 years ago and telling those people that they need to start preparing for a rocket trip to the Moon. Sure, it might make for interesting discussion around the camp fire, but from their point of view, they need to keep figuring out how to survive and build better stone tools.
We need to keep exploring the solar system with unmanned probes, and figure out how to survive here on Earth for the next few thousand years at least.