Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!lll-crg!ucdavis!ucbvax!space From: jef@LBL-RTSG.ARPA Newsgroups: net.space Subject: Re: Scuttle the Space Program? Message-ID: <37378.509307074@lbl-rtsg.arpa> Date: Thu, 20-Feb-86 13:11:14 EST Article-I.D.: lbl-rtsg.37378.509307074 Posted: Thu Feb 20 13:11:14 1986 Date-Received: Sun, 23-Feb-86 18:53:00 EST Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 86 In reply to Andrew J fine's long message about learning to live with ourselves here on Earth before we think about moving out into space... First, I found the tone of the message fairly offensive. Mr. Fine assumes that he is the only one asking these kinds of questions - which he's not - and that only he has the right answers - which he doesn't. He assigns all sorts of evil motivations to those who would disagree with him. Well Andrew, I'm one of those people, and I consider myself to be an extremely moral being, so tone it down, ok? As for answering the substance of the message, REM posted a sufficient answer just a few days ago. It appeared in the space digest yesterday, and it ably refutes the idea that we should get clean up Earth before moving to space. I've appended an answer of my own, that I wrote a few weeks before the Challenger explosion. In it, I attempt to show that we *must* move out into space *now* - it's a moral imperative. --- Jef Long-Term Viability by Jef Poskanzer The only long-term way to assure the viability of Earthlife, including whales, gorillas, cephalopods and everything else as well as humans, is to get off this planet. As long as Earth is the only place we live, we are vulnerable to extinction. There are all sorts of nasty things that could wipe out all life on this planet. A really large comet could hit us, pasteurizing the planet. Sirius could go supernova. Maybe a new form of life could evolve, poisoning and replacing us the way we poisoned and replaced hydrogen-breathing life a billion years ago. Furthermore, we have a time limit. Our sun is getting hotter. It has been getting hotter, very slowly, for as far back as we can measure - billions of years. So far, the biosphere has managed to keep the local temperature constant by steadily decreasing the proportion of greenhouse gasses in the atmosphere - carbon dioxide, water vapor, methane, etc. However, if the sun continues to get hotter for only another 100 million years, that solution will no longer work - even getting rid of every last molecule would still leave the planet too hot. There will be a runaway greenhouse effect leaving Earth looking something like Venus. Not a place you'd want to live. So, you may ask, why am I worrying about events that won't happen for 100 million years? Surely we've got plenty of time to start colonies in the asteroids and begin moving out to the stars. Well, we actually don't have very much time at all - 100 years, 200 at the outside. Humans have been using up the natural resources of this planet at an amazing rate, and now we're running out. Soon we're going to have to fall back to a low-energy, renewable-resource, labor-intensive way of life. I have two objections to this. One is the immediate loss of life. 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. My second objection is that if we go to a low-energy life-style now, we will never be able to reverse that decision. The easy resources are gone. The close-to-the-surface ores, the coal, the oil - we've used it up. Now it takes high-tech energy-intensive machinery to extract the resources needed to keep the high-tech machinery going. We can keep going like this for a little while longer, but if we give up high-tech we won't be able to start again. We would have to wait for continental drift to expose new ores, which would take a hundred million years or so, and by that time - you guessed it - runaway greenhouse effect. So, if we back off now, we are putting a permanent, irrevocable ceiling on the number of human individuals who will ever live. One billion people for 100 million years means at most five times ten to the fifteenth people will ever live. If, on the other hand, we spread Earthlife to the stars, then the next 100 million years will see the birth of at least ten to the twenty-fourth humans, plus unguessable numbers of intelligent descendents of the gorillas, dolphins, octopodes, etc. A short-term benefit of moving out into space is that by making use of asteroidal resources, we can avoid the catastrophic collapse of Earth's civilization. We can spread out the transition to world-wide Ecotopia over the next 500 years. This will allow us to reduce the population to the necessary level through birth control and emigration instead of war, famine, and disease. It's kind of frightening to me that within the next two centuries, we will collectively make a decision that will allow or prevent the existence of many septillions of people.