Al,
Have you considered working the Singularity into your projections? The notion that in 50 years or so Artificial Intelligence will surpass human intelligence, that computers will start advising, then being given control over, more important human decisions? I'm not talking about Skynet and Terminator, just the notion that computers will become so capable that they can take over so much of what we aspire to do. It costs so much more to lift a 200-lb. organic intelligence into space, along with the complex inputs (food, atmosphere, water) that they require to stay there, when for the same amount of lift you could put dozens of intelligent robots into space, that need only to collect the sunlight that is in abundance, and the raw materials that are a few delta v's away, and start building--well, whatever they and we decide to build. Habitats, solar panels, interstellar craft. In 100 years it will only be the humans that need to be lifted off earth, because the robots can be built that will gather and build everything for us. As we struggle with our first manned missions to the nearest stars, robot craft will have visited half a dozen systems, and by the time we're colonizing our third star system, they'll be hundreds of stars ahead of us. I just hope humans will learn to retain some autonomy, and not just flop into the robots arms and say, "entertain me."
Brad W.
