REM@MC.LCS.MIT.EDU (Robert Elton Maas) (02/28/86)
B> Date: 23 Feb 86 13:58:30 GMT B> From: brahms!gsmith@ucbvax.berkeley.edu (Gene Ward Smith) B> Subject: Long-Term Viability B> No matter where we lived, we would be vulnerable. You obviously didn't listen to the original argument when it was presented years ago (see some book by Asimov I think on size of various disasters; anybody recall the name? also see archives of SPACE) Here it is again: True any single point of life is somewhat as vulnerable as any other single point. But the purpose in getting into space isn't to simply move to a point in space and pull up roots from Earth. The purpose is to spread throughout a wide volume so that a disaster big enough to destroy all life on Earth is just to small to destroy all life throughout a vast array of space colonies. Even having a teensy life in space, in addition to life on Earth, is better than either alone, because there are modes of disaster that affect one or the other but not both. But largescale life in space is much better than being stuck on this itty bitty Earth speck. (Compared to a single human being, Earth is humungous. Compared the to the disaster we can create with one thermonuclear war, Earth is a single point in space.) Remember that it's very easy to kill a single ant, by stepping on it, but difficult to kill that colony that is dispersed underground that keeps sending ants one by one into your kitchen. You would have to spend a lifetime stepping on ants one by one and still you'd never get them all. If life were dispersed throughout the universe, we could have thernuclear wars every year and still not stamp out all those colonies. Thus getting into space on a large scale is a good survival strategy. Sure there are bigger disasters that can get whole clumps of colonies in space, but with enough colonies over a large enough volume, the only disaster that can get them all is the total destrution of the whole universe, which won't happen for a very long time if our current theories of cosmology are even approximately correct. B> A large, space-going cephalopod could come along and eat the whole planet. B> Get serious (pun intended) Sirius isn't going to blow up. Why don't you B> learn some Astronomy if you like space so much? It is very interesting B> stuff. Why don't you learn some Astronomy. (Sorry, just retaliating; I could slightly wrong too, so please anyone who knows better please do correct any errors I make.) Sirius *is* going to blow up, go supernova probably, in about 10 million years, long before our Sun goes red-giant. But probably Sirius and the Sun will have drifted far away by then. More dangerous are Betelguese and Antares, either of which could go supernova within the next 1000 years, before they drift too far away. >Well, we actually don't have very much time at all - 100 years, 200 at the B> Oh no! An emergency! Call an ambulence! Are you trying to be an asshole here? Come on, this isn't an emergency, like within 3 minutes the Earth will die, and nobody said it was, so what the hell are you trying to get at? Given that it will take us 50 or 100 years to get fully developed space habitat, we'd better get working soon if we have only 100 years. Instead of looking only at emergencies (if it doesn't need to be done this very minute, then don't make any plans at all, keep putting it off), how about looking at longrange plans too? If we wait until we have only a week left to get into space, we aren't going to have enough time. Look at the 9 years it took just to get a few astronauts on the moon, and an additional 12 years to get the very first flight of the shuttle. We have to continue working year by year, not say "well, it doesn't have to be done yet so let's wait longer". (Ad hominum remark: do you wait until April 15 before even looking at your income tax forms?) >Ecotopia can't support five billion people. Maybe one billion. That >means four billion people must die - which is about fifty times more than >have died in all wars so far combined. B> And space colonization, even if successful, would not prevent it. Birth B> control might. Not clear. If people on Earth are offered a choice, do it the old way having as many children on Earth as they want, with not enough food for them, so most will die, or do it a new way, have one child on Earth and as many as they want in space, with the latter having abundant room to live and abundant energy and materials for growing abundant food, we may be able to have birth control on Earth without people who use that birth control basically dying out by not having any children anywhere. We may prevent overpopulation of Earth without simply doing genocide by birth-control on the present Earth population. B> I'm confused -- do you have a high faith in scientific and technical B> advancement, or a very low one? It seems you adopt either point of view B> to suit your convenience. He's saying that 6E9 people on Earth requires high-tech, which in turn requires either cheap energy on Earth (read fossil fuels, which can't last more than 100-200 years) or cheap energy in space (which can last at least 5 billion years around this star and longer if we move behond). B> Oooh --- it sounds so easy! We'll just roll out to the stars (THATS not B> hard) and live forever. Why do I find it strange to think that if you have B> just proven it impossible to do on the earth, it should be so easy somewhere B> else? Because there isn't enough sunlight falling on this teensy itty bitty speck of planet we call Earth, whereas there's immense sunlight total emitted by the Sun that we could collect and use if we went out there and collected it. Work out the trigonometry yourself. The Earth is 8,000 miles in diameter, located 93,000,000 miles from the Sun. What fraction of the solid angle is occupied by the Earth? I think it's something like one part in a billion. If solar energy striking Earth can provide food for 1 billion people (the other 5 billion die of starvation, and the 1 billion must maintain zero population growt), total solar energy can provide food for 1,000,000,000 billion people (6 billion we have now plus 999,999,994 more billion as our population grows. It's the nine orders of magnitude more energy out there, just for the Sun, not counting all the 100 billion other stars in the galaxy, and the billions of other galaxies, that makes longterm life possible in space and impossible except for the lucky few survivors on Earth. B> Why is there so much unmitigated bullbleep on net.space? Come on, the above isn't bull bleep (except for your remarks; sorry for ad hominum, just retaliating). There are good solid reasons for getting to space if we want to survive long. B> Is this some kind of obscure religious cult I haven't heard about? No, it's just our desire to survive tied with our understanding of our current situation and of the prognosis based on current scientific theories. Unless and until science says the Sun isn't getting warmer or won't go red-giant and will burn forever via some magic perpetual-motion machine or God's intervention or somesuch. I don't believe that possible, so I'll stick with current theory that the Sun won't go on much longer than 5-10 billion years further. If you choose to ignore science and believe some unsupported view, I'd say it is you who is following some religious cult. B> I thought space colonization was a possibility technology could offer B> us -- if we used our knowledge and planning ability. It is. That's the point of this mailing list / digest, first decide what we want to do, long range goals and tasks toward those goals, then decide how to get those tasks accomplished. So we've been debating why go into space and on what scale, and how best to get into space. B> Some of you seem to think you are going to wish yourself to Epsilon B> Eridani. "If you wish upon a star ... " I am not aware of anyone on this list who claims just wishing will get us there. We have been doing a lot more than wishing; brainstorming, petitioning Congress and President, and some of us are even helping finance private venture.