This thread has spilled over from the feasibility of interstellar travel thread. Scylla there posited that since the Earth’s resources are finite, a good reason for space travel is to get a hold of more (correct me if this wasn’t your point, exactly). I countered that human ingenuity has overcome limitations of resources in the past, and will continue to do so in the future. Now I suppose asteroid mining could be considered a part of this human ingenuity, but I belive we have all we need beneath out feet. Besides which, it has been nigh on to thirty years since we brought any extra-terrestrial material back, and the near future is looking dimmer with the latest Mars failures. So, I am being overly optimistic about my fellow humans? Or are we really cornholing ourselves?
It’s not how you pick your nose, it’s where you put the boogers
No, Malthus wasn’t right. (His principal reasoning was sound, but the devil is in the details and he got the details horribly srong.)
I do not know about cornholing ourselves, but the human race is definitely backing itself into a corner. The human race has also demonstrated a remarkable ability to turn corners. People who make confident predictions about which way the balance will fall on this one are more confident prognosticators than I, though I generally wonder whether their confidence is based upon thorough study or thorough ideology.
The best lack all conviction
The worst are full of passionate intensity.
*
When and if our space-travel technology becomes efficient enough that space resources are worth more than it costs to retrieve them, we will start gathering resources from places off the Earth. But not until then.
I believe that solar, geothermal, and wave power will be the power of the future. But they won’t come into prominence until fossil fuels are prohibitively expensive, which won’t be anytime soon.
Judges 14:9 - So [Samson] scraped the honey into his hands and went on, eating as he went. When he came to his father and mother, he gave some to them and they ate it; but he did not tell them that he had scraped the honey out of the body of the lion.
A bit of confusion over some concepts here.
Are our resources finite? Absolutely; assuming for the sake of argument that our resources are limited to the Earth, I can demonstrate that the Earth is finite; thus, our resources, by definition, are.
Are our resources limited? Ah, a much more difficult question to answer. At any given point in time, they are limited. All resources are finite (see above); at any given point in time, we can only use some of them; therefore, they are limited.
The kicker comes in when we move in time. Five hundred years ago, aluminum and petroleum were not resources; they were unsuspected and useless goo, respectively. Five thousand years, no metal was a resource; one worked in bone, stone, and wood, just like the uncounted generations that went before. Some changes, e.g., the substitution of fission and fusion for combustion, we can imagine. Some we can’t; of course, that means we can’t rely on them, either (many discoveries are only obvious in hindsight). Changes of scale are important, too; how many of the Seven Wonders of the World could now be trivially reproduced (except that, the Colossus of Rhodes being so trivial, no one’s going to be impressed if we set up a duplicate in San Francisco harbor)?
It is often said that “anything is possible”. In fact, very few things are possible, and most of them have already happened.
With current launch vehicle technology, it takes 6 million pounds of kerosene and liquid oxygen to propel a 50-ton payload into an Earth-escape trajectory. This in itself is an enormous expenditure of resources. Were we able to figure out a “cheap” way of producing this kind of launch energy, we could use it as a means of generating cheap electricity, too, thus reducing our consumption rate of natural resources and defeating the original purpose of getting into space to get more resources.
Launching something into space costs about $10,000 a pound right now. This is because a huge amount of energy has to be expended to launch something “uphill,” out of a gravity well.
Sending something “downhill” into a gravity well is not quite so diffiult.
This is why the space shuttle can essentially glide in for a landing without rockets or boosters.
Once you have the infrastucture up in space, sending things back down is no big deal.
Also, most of our launchers are Eisenhower era dinosaurs of inneficiency developed under “cost-plus” accounting. The launch uphill can be done a lot more efficiently than it is right now.
Most of the energy in those 6,000,000 pounds of kerosone/LOX do not go to boosting the payload; they go to boosting the 6,000,000 pounds, etc.
Scylla also has a point in saying that we are boosting out of a gravity well. Consider that in order to make that load effectively weightless (never mind actually going someplace, it is necessary to have, in the first instant, 6,000,000 pounds of thrust.
It is often said that “anything is possible”. In fact, very few things are possible, and most of them have already happened.
So you think we can harness rocket power and thereby excape the need for natural resources? What the heck are you talking about?
We already do. These modified rockets are called generators. Some of them work on an advanced scientific technology called “internal combustion.”
You don’t even need to do the math to figure out that population growth, and the ever increasing energy needs of a growing technological society are eventually going to put quite a strain on fossil fuel, metals, and other natural resources. Asteroids are a viable source that will get exploited sooner or later.
Say we develop fusion. Big deal, eventually we need more Helium 3. Solar power? How much of the earth do you have to cover at 10% efficiency before it makes sense to go to orbit where you can get 100%?
Once nanotechnology has been developed to the point where we have nanites that can assemble objects atom by atom, natural resources will be virtually unlimited. When something is thrown away, its atoms are still there, they’re just in a place and form that make them useless to us. Except for the stuff that was shot into space, we still have all the matter that was there when the Earth was formed.
Life is a tragedy for those who feel and a comedy for those who think.
No, I’m not attacking Tracer. I’m attacking the idea that a rocket represents a viable energy source.
As a generator of any kind it is hugely wasteful.
Tracer said:
quote:
Were we able to figure out a “cheap” way of producing this kind of
launch energy, we could use it as a means of generating cheap electricity, too, thus reducing
our consumption rate of natural resources and defeating the original purpose of getting into
space to get more resources.
endquote:
Generating electricity for consumption from rocket exhaust is just silly, and would not affect our need for new resources at all.
Tracer:
But maybe I shouldn’t have been an ass about the way I said. My apologies. I was lost in the heat of debate.
I think the original point is that if we could generate vast, cheap amounts of the requisite energy, say, through dog farts, we could apply that energy equally to both launch technology and terrestrial technology. The concept of electromagnetic slingshots as a means of whipping payloads into orbit has been around for a while.
Dee da dee da dee dee do do / Dee ba ditty doh / Deedle dooby doo ba dee um bee ooby / Be doodle oodle doodle dee dohhttp://members.xoom.com/labradorian/
I think Tracer specifically referred to harnessing the power of a rocket’s exhaust to generate electricity. That is silly. How do you follow the rocket to harness its exhaust?
Certainly nothing was said about dog farts or railguns, and I don’t think it was implied.
Read it again, and tell me if you think I’m wrong.