He did brilliant work on QED and other physics. The Dyson sphere is not one of his brilliant ideas. He has also been on the climate denial side, and continues to be as far as I know. > > >> >* * >> *Maybe I will qualify that, a solid shell enclosing a star is stupid.* > > > Dyson calculated that there was enough matter in the solar system to > make a non-rotating sphere around the sun with a of 93 million mile radius > about 3 meters thick. Perhaps you think he said biological humans were > suposed to live on that sphere but he did not, if he had that would indeed > have been stupid for a number of reasons including the fact that by the > time it is built there will no longer be biological humans. A Dyson sphere > is just > a energy collecting device. > Any IGUS that might engage in this sort of thing would be doing it for the long haul, as in millions of years. Such a giant project would be meant to be around for a long time. If so the decoupling of the sphere from the star is problematic, for even small gravitational perturbations from other stars will cause the star to deviate from the center. This would be a large management problem. Any hyper-advanced IGUS will most likely not generate energy this way, It would be far smaller and compact to generate energy by converting matter directly to energy via quantum gravitation or black hole physics. Such being could use their stellar system material to convert around a million tons per second into energy to generate as much energy as a star like the sun. So large Dyson sphere needed. > > > *> Gauss told us why. Integrate the gravitational field across a >> Gaussian surface inside your Dyson sphere. What you get is the mass of the >> star. The Dyson sphere does not contribute; it is completely >> gravitationally decoupled from the star.* > > > > > > I fail to see why a device would need to be gravitationally coupled to a > star to collect solar energy from that star, in the case of the sun the > energy collected would be > > 385 > > yottawatts, a > > yottawatt > > is 10^24 watts. > > Some > > have > > said > > that instead of a non-rotating Dyson sphere ET might prefer > > to build > > trillions of > > separately > > orbiting > solar > energy collectors and make a Dyson swarm, but at a distance the two > > things > > would look very > > similar > . > > >* * >> *I suspect if there is intelligent life in other corners of the universe >> they probably do not assume control of that much matter and energy. I >> question whether space colonization is really practical. It certainly can't >> be practical if there is no economic justification for it.* > > > > Economics will be quite different in the future, > > once Nanotechnology has been perfected its difficult to imagine something > that > would be > possible to do but very expensive to do. > My point is that the only reason I can see putting humans in space is for industrial or technological applications. It is of course entirely possible that any industrial process in outer space will end up being robotic with no humans needed as well. > > > > >> * > We can do loads of science in space with out a single astronaut. * >> > > Absolutely, and do it better! But in a century few humans will be > biological. . > > >> > ** >> *Here I am just talking about the moon and maybe rotating cylindrical >> habitats fashioned from nearby asteroids.* >> > > That has nothing to do with Dyson spheres or anything I'm talking about. > > Even assuming Dyson spheres exist by some IGUS they started out a lot smaller. > > > >> *Traversing interstellar distances and building mega structures is may >> orders of magnitude beyond anything we might fashion in the coming 50 or >> 100 years. * >> > > > The universe is 13.8 billion years old and the last star won't burn out > for another 10 trillion years and you think the fact that we can't do > something for 50 years has cosmological implications? > The only conceivable cosmological implication for intelligent life is that it performs a cosmological version of the Wheeler Delayed Choice Experiment. Maybe a huge ensemble, maybe infinite if the universe is infinite, number of measurements of cosmological parameters, say in particular the inflationary cosmological parameter, serves as a superselection of this value in a WDCE. This would involve some physics with respect to the relationship between Bayesian updates and the ergodic principle that are not understood now. We humans might just be one IGUS who makes this measurement and the mean of these measurements in a post update WDCE sense defines the parameters of the observable universe. Other than this there is no real implication or possible role we have in the universe, other than maybe just trashing everything out we can get our hands on. I rather suspect this video on why finding ETI might not be to our advantage does have some point. I strongly suspect we humans may reach a point where we can no longer manage our synthetic world of ever greater complexity. For instance, with global warming I suspect that rather than actually doing something to adjust ourselves we will instead engage in planetary climate/weather control. The complexities of this, both technical and political, are formidable. Never mind the many orders of magnitude greater complexity in managing something like a Dyson sphere. We might also ponder what I think is a sort of mental dumbing down that is going on, where as our mental stimulation becomes more electronic or virtual the less deep it is and the more it involves narrowed time frames. A future where few people actually read much of any real substance and at the same time we are faced with ever greater complexity in the world we manage is a situation headed for a collapse. Maybe one reason we do not find hyperadvanced civilizations is that all possible IGUS prior to us, at least in this neighborhood, snuffed themselves out. We will most likely follow suit. Cheers LC > > > >> *I suspect any possible ET on the other side of the Virgo cluster might >> not be that more energetically powerful than we are. Even if they are very >> advanced I suspect limits to growth* >> > > > That could be true only if there is some new law of physics that we know > nothing about that prevents it because unlike time machines or faster than > light travel no new science is needed to make Drexler style Nanotechnology > a reality, it just needs greatly improved technology. > All it would take is the > > engineering > > ability to move things with atomic precision, > > and we know > > something like > i > t can be done > > in principle > > because we have a existence example, life. Admittedly it's > > very > > crude version of Drexler style > > Nanotechnology but it's about as good as you could hope for considering it > was invented by random mutation and natural selection. And life was good > enough to manufacture me, every atom that's in me today came from last > years potatoes, and life was good enough to manufacture last years potatoes > from nothing but water, carbon dioxide and nitrogen from the air and a few > trace elements from the soil. Not bad but I have a hunch intelligence can > do > better, one hell of a lot better, and just a few weeks ago there was a > report that makes me think my hunch is correct; somebody made a > 25-nanometer-long robotic arm with precise nanoscale movement that is at > least five orders of magnitude faster than anything made before: > > > http://www.kurzweilai.net/remote-controlled-dna-nanorobots-could-lead-to-the-first-nanorobotic-production-factory > > > >> > >> *We humans are still drunk with our sense of power in the fossil fuel >> age. If very advanced IGUS do evolve they might not become these galactic >> engineers, but may more in a way like an assembly of philosophers who are >> at peace with the biota on their home planet.* > > > If ET wants to make new philosophic discoveries that needs brainpower, > and a Dyson sphere produces a lot of power; information is physical and it > takes energy to manipulate it, but yes, what you say above is > a very real danger, if ET exists he > must be > a lotus eater with no intellectual curiosity > > about > > the universe he lives in. > > And it's not like it would > be > difficult > or expensive to learn more > , ET doesn't even need to travel to the stars, ET just needs to send > one Von Neumann probe to one star. > > Even assuming ET can't send space probes any faster than we can ( a > ridiculously conservative assumption) then almost instantly from a cosmic > perspective (less than 50 million years) the entire Galaxy would be > unrecognizable. It's not as if this would take some huge commitment on the > part of ET's civilization, in fact even a individual could easily do it. If > Von Neumann probes are possible at all, and I can't think why they wouldn't > be, then they're going to be dirt cheap, you buying a bag of peanuts would > be a greater drag on your financial resources. Even if many or even most > ETs think that sending out a > V > on Neumann probe would be a bad idea there will always be somebody who > disagrees. And it only takes one. > > Although > I hope not > , > > turning into a navel gazer > may be the fate of any > > intelligent conscious > being > if it had full access to its emotional control panel. Regardless of how > well our life is going who among us would for eternity opt out of becoming > just a little bit happier if all it took was turning a knob? And after you > turn it a little bit and see how much better you feel why not turn it > again, perhaps a little more this time. Maybe drug addiction is the first > signs of that very dangerous positive feedback loop. During most of human > existence this was a non-issue but then about 8000 BC alcoholic beverages > were invented, but they were so dilute you'd really have to work at it to > get into trouble. Then about 500 years ago distilled alcoholic beverages > were invented and it became much easier to become a alcoholic. Today we > have many drugs that are far more powerful than alcohol. What happens if > this trend continues exponentially? > > Perhaps a > n > eternal orgasm will become more important than consuming more and more > energy, and more important than anything else, and more important than > everything else put together. Perhaps the world > doesn't > end in a bang or a whimper but > with > a > mown > of mindless pleasure. > > > John K Clark > > > > > > > > -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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