Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Sat, 9 Mar 91 02:27:40 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 9 Mar 91 02:27:36 -0500 (EST) Subject: SPACE Digest V13 #248 SPACE Digest Volume 13 : Issue 248 Today's Topics: Humanity's Launch Window, final draft Not about space (sorry) Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 6 Mar 91 21:53:43 GMT From: hpfcso!hpfcdc!ajs@hplabs.hpl.hp.com (Alan Silverstein) Subject: Humanity's Launch Window, final draft Here is the final (for now) draft of my essay, "Humanity's Launch Window", a troff -mm document. Thank you to all who responded to my earlier posting. I included in the sharchive below a second, flat document that incorporates most of the feedback mailed to me. These documents are not copyrighted. Please feel free to distribute them far and wide. I intend to do that myself. I haven't had time to follow this newsgroup. It appears a discussion spawned from my earlier posting and I missed it. Sorry about that. -- Alan Silverstein # This is a shell archive. Remove anything before this line, # then unpack it by saving it in a file and typing "sh file". # # Wrapped by ajs at hpfcajs on Wed Mar 6 14:46:49 1991 # # This archive contains: # launch.window launch.resp # # Error checking via wc(1) will be performed. echo x - launch.window cat >launch.window <<'@EOF' .\" Version 4, 910306 .\" Printing this paper requires troff -mm. .\" ---------- .\" A simple, short page header: .de TP .sp 3 .. .\" ---------- .br .S 16 .ce 1 .B "Humanity's Launch Window" .\" ---------- .S 12 .sp .ce 2 Alan Silverstein .\" date: \*(DT .\" ---------- .sp .P .B "Five billion years from now." That's when the Sun will expand into a red giant star. It will engulf and vaporize the Earth. All of our dreams, inventions, creations, artifacts, and remains will become a mingled gas. Also our pollution, landfills, war machines, inner cities, and petty differences. The thought is both reassuring and humbling. Everything we affect is headed for ultimate oblivion as a hot gas... unless before then we are able to \(em move off the Earth; move the Earth; change the Sun's life cycle; or make something .B really exciting happen. .\" ---------- .P .B "Four and a half billion years." That's how long it took for self-awareness to appear on the Earth. We seem to be the first Earth species capable of departing the planet. It took over four thousand million years for life on our world to reach this point \(em for our ``launch window'' to open. .\" ---------- .P .B "Many thousands of people, all peacefully cooperating." That's what it takes to launch a payload from the Earth. Discovery of the Americas by Europeans required a few sailing ships. The exploration could be accomplished and the exploitation (ethical or not) begun by perhaps fifty people in one lifetime. A successful space program is much, much more demanding. .\" ---------- .P Wonders beyond comprehension await us beyond our Earth. To grasp those riches requires enormous investment. It takes raw materials and the technology to render them. It takes many, many people, at peace with each other in a stable society, wealthy enough to make investments whose return is measured in generations. .\" ---------- .P .B "Thirty years." That's how long humanity's ``launch window'' has been open. Our precious Earth is crowded. Our raw materials are being consumed. .B "Our launch window will close." .\" ---------- .P .B "How long do we have?" It is anyone's guess. I think no more than fifty years. Possibly much less. After that \(em no one, no group, will have the resources, the time, the energy, to spare on expanding into space. (Historically we have always avoided permanent decline. One nation's fall has been another's rise. Room and raw materials have always been available somewhere. But we have never been so interconnected, interdependent, crowded, and dependent on technology as we are now. I hope I am wrong, but what if I am right?) .\" ---------- .P The Dream might survive, but as an escapist fantasy on a crowded world become a prison. A world of inmates bound by gravity's bars. .\" ---------- .P .B "Imagine it." Nine billion years for Earth. An eighty year launch window for humanity. Now .B that is the big picture. Perhaps, in the long run, it is the only view that matters. .\" ---------- .P .B "Now is our species' crux move." Our one shot at virtually infinite wealth and discovery. We can pursue the Great Adventure. Or we can fritter away our opportunity \(em and wake up one day to discover it's too late. We can let our launch window close. .B "Which do we choose?" @EOF if test "`wc -lwc launch.resp <<'@EOF' SOME RESPONSES TO "HUMANITY'S LAUNCH WINDOW" By Alan Silverstein Last update: 910306 Below are some responses to an earlier draft of my essay. I received them by electronic mail and got permission to edit and distribute them. I removed the authors' names so they can remain anonymous. I was quite impressed by the thoughfulness and eloquence of the replies. The general theme of the rejoinders is: I am overly pessimistic in asserting that humanity's launch window will close soon, if at all. Perhaps. I hope so. Only time will tell. I will feel my effort was worthwhile if the concept of a "launch window", that *might* close, becomes a common and widespread idea. The point of the essay is to spread the idea, in the hopes of it motivating people to action. Now, some opposing viewpoints. ________________ I have to say that I do not agree with your assessment that humanity has only 50 years (or thereabouts) to make it into space. The problem is that you lump the human population of the earth into one unit, and call it "humanity". The earth is, for better or worse, very divided. It is divided into 200+ nations, which are in turn divided into regions (states, republics, etc.), cities, and so on. The economies of all of these divided parts of the earth are always in a constant state of fluctuation. There are some very rich nations, and some very poor nations. There are also some nations that are getting richer, and some that are getting poorer. Some are getting more advanced technologically, while some are decreasing in technological capability. Right now, the U.S. has the biggest economy in the world. You would probably assume that it is entirely up to us to get humanity off of the planet. This is not necessarily so. To pull an example from history, Spain was the first country to start colonizing the New World. However, the development of the New World was not entirely up to Spain. When Spain eventually became a less effective world power, England took over and started colonizing. What I am trying to say is that, even if we (the U.S.) do not succeed in putting colonies on other planets, there will always be other nations that can step into our place and take over the job... [ajs: That is where I disagree. I think we are all linked in a complex, relatively fragile web, a network of infrastructure and interdependencies. I don't think it will always be true that some other nation can take over. Maybe in 20 years. But in 50? With a crowded, polluted *world* dwindling in resources? Possibly facing various global disasters like greenhouse or UV?] It may well be that we are the Spain of the Space Age, to eventually be succeeded by some other country (the European community, perhaps) which will put colonies on other planets. This does not really matter. What does matter is that there will always be rich nations capable of building space programs. I do not think that the world, as a whole, will ever become so poor that no nations would be capable of space travel. The world as a whole is getting more advanced technologically, and there are no signs that technological progress is starting to slow down. Even if some nations grow poorer, others will always grow richer, and the overall level of technology for the entire world will always be one of steady progress. This is the result of the divided economies of our world. ________________ If you truly believe that our launch window will only last 50 years, then it is not only a good idea, but also a responsibility to our descendents for you to write your essay and get it spread as far as you can. To both common people and to Those Who Make Things Happen. Even if our window is only measured in hundreds of years you should do this... ________________ I think that your premise is wrong. The notion that humanity has reached the peak of economic growth is, of course, very depressing, so I have a good psychological reason to ignore the truth. On the flip side, I think the "Limits to Growth" crowd are using the cry "we are poorer than we think" as a way to call attention to their particular agenda. One approach to search for the truth would be to make an honest attempt to model economic trends; unfortunately this must contain many assumptions, so it will usually wind up reflecting the modeler's world view; and the exercise gives us outsiders mostly information about the guy's politics. Another approach is to look back over history and say "on average, we are richer each year than the the year before, so long term we will be arbitrarily wealthy". This might be reason for hope, but is not conclusive, since it will be true right up until the downturn. I think our millenium still has a long suit in technology, which I expect to cure most of our present ills. ________________ I just see no evidence presented that the launch window is 80 years rather than 80,000 or 80,000,000. Like you say, it's anyone's guess, so why should we believe yours? That, I think, is the weak point of the essay. You assert that availability of resources, time, energy will somehow decline in the future. Since this is in direct contradiction of the trend of all human history, you need to support this assertion. Sure, the Earth is crowded, and this may become a crisis in the near future, but demographic studies show that with higher technology, more wealth, and better opportunity, birth rates decline. Look at Europe vs. the third world. Are you projecting a decline in technology, a dark age? It is possible, but civilization has had several already, and always recovers. And sure, we are using up some resources, but there's no projected critical shortage of any necessary raw material for hundreds of years. (There was a Scientific American article on this a couple of years ago) For the farther future, it is likely that we can make much better use of common resources (hydrogen fusion, solar power). Where do you get 50 years from? [ajs: I get it from intuition -- that is, my unconscious mental processing of the sum of all things I know. Very much a subjective estimate.] The first part of your essay takes a very long perspective - billions of years; but then you inexplicably become very myopic and talk as if history were about to end. Maybe you have good reasons for thinking this, but they are not convincingly stated. Sorry if I am being too hard on your essay. I agree with its goals, but I think you need more facts and less emotionalism. I encourage you to continue. [ajs: I considered this feedback. I decided my goal was not to write "yet another" technical article. My emotions were what motivated me to write this essay. It is and shall remain an emotional appeal, not a research paper. Perhaps many will disagree with its premises; so be it.] @EOF if test "`wc -lwc