# Dyson sphere

Discussion in 'General Science & Technology' started by OmegaSeven, Oct 28, 2001.

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1. ### OmegaSevenRegistered Member

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10
Who and what would be capable of building one of these things? Were would you obtain the resources and knowledge to build such a massive structure?

3. ### Pollux VRa Bless AmericaRegistered Senior Member

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6,495
to what are you refering?

5. ### Avatarsmoking revolverValued Senior Member

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19,083
agree

What is Dyson sphere?

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2,235
8. ### Pollux VRa Bless AmericaRegistered Senior Member

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6,495
Wow-that's pretty big.

Imagine TWO dyson spheres.

Google is a prert damn good search engine isnt it.

9. ### SeekerOfTruthUnemployed, but LookingRegistered Senior Member

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358
Only an extremly advanced civilization. One that could manipulate matter at the atomic level, thereby creating the materials it would need to construct a Dyson sphere.

Which begs the question, why do it?

10. ### machaonRegistered Senior Member

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733
And now a word from our sponser...

Interviewed October 1978 by Monte Davis

"One should expect that, within a few thousand years of its entering the stage of industrial development, any intelligent species should be found occupying an artificial biosphere which completely surrounds its parent star."
For 20 years now, Professor Freeman J. Dyson has been discussing mind-boggling prospects in just that calm, matter-of-fact, "one-should-expect" way. It is his hobby, he says disarmingly, something that grew up alongside his career as one of the finest mathematical physicists of our time. To his colleagues at Princeton's Institute for Advanced Studies, Dyson is known for his understanding of what goes on in the core of a star or in the interaction of high-energy beams of subnuclear particles -- contributions that have earned him the American Institute of Physics' Heineman Prize, the Royal Society's Hughes Medal, among other honors.

To a wider circle, though, he is known for imagining an artificial biosphere -- or environment in which life can exist -- called the "Dyson shell." It is a vast structure built by dismantling a Jupiter-sized planet and using the raw material to provide living area millions of times greater than that of any planet. He further suggests that the powerful gravitational field of a white-dwarf binary star might serve as a super-slingshot to accelerate interstellar voyagers free of fuel costs . . . and that an army of self-reproducing automatons could mine the ice of Saturn's moons and use it to make chill, arid Mars a garden planet.

Freeman Dyson was born in Crowthorne, England, in 1923. He attended a public school in Winchester where his father was a teacher, entering Cambridge during World War II. After two years of service with the RAF's bomber command, he took a B.A. in mathematics (his specialty was number theory). Dyson came to the United States in 1947, after a few years at Cambridge and the University of Birmingham. At Cornell, he was drawn from mathematics into physics by the influence of Richard Feynman and Hans Bethe; in 1953, he moved to the Institute for Advanced Studies where he has worked since then.

Dyson's speculative side lay dormant, he says, until 1956 when he met physicist and bomb designer Ted Taylor at a series of conferences convened by the General Atomic Co. in San Diego. They worked together on the fail-safe design of the TRIGA research reactor, and on Project Orion -- a plan to propel spacecraft far larger than Apollo (even the size of a city!) by detonating nuclear or thermonuclear bombs behind a "pusher plate." Since then, the two men have been close friends, stimulating each other in imaginative synergy. Dyson also has worked for the U.S. Disarmament Agency, served as consultant to NASA and the Department of Defense, and is a former chairman of the Federation of American Scientists.

Today, at 55, Dyson is more freewheeling than ever in his speculation. Conversing with him leaves one slightly breathless as he jumps from details of a rocket that might be launched tomorrow to the outlook for the next ten billion years of evolution. After a while, one begins to sort out what he says by how he begins each sentence. "It's inevitable . . . " signifies his certainty about the next century or two; "It seems obvious . . . " enlarges the scope to the future of mankind on the earth; and "One should expect . . . " can reach from the Big Bang to the end of the cosmos.

Dyson is a small, compact man with sharp features ("I don't have much hope for your pictures," he warns; "my children always say my nose looks like the beak of a bird") frequently softened by a half-smile. When the smile breaks into laughter, which is often, the laugh is that of a hearty, delighted young man, and it seems almost too large for its owner. However much he may deprecate his "hobby," Dyson clearly enjoys it -- as well as the reactions of his more staid colleagues.

In the last decade, Dyson has been watching and advising the growth of Princeton physics professor Gerard O'Neill's plans for self-sufficient colonies in space, supplied with raw material catapulted from the moon by an electromagnetic "mass driver." The interview began with that subject:

Dyson
I think O'Neill saw what I and others did not see -- that the public was ready to get excited about space again. It seemed after Apollo that people were turned off; they'd seen too many moon rocks. I thought it would be hopeless to get people interested in space colonies for twenty years or so. But O'Neill showed that you could get them interested, especially young people. It showed great courage and insight on his part.

OMNI
Is it because he's talking about colonization, rather than a there-and-back expedition like Apollo? Or because he's showing how the colonies could pay for themselves by building solar-power satellites to supply energy to earth?

Dyson
I doubt the economic aspect was that important. It came later, when O'Neill was trying to get the Establishment -- NASA and the Congress -- interested. He had to sell it on economics, but as far as the public is concerned, it isn't that.

OMNI
How do you explain O'Neill's success in view of the current mistrust of "big technology," of big government projects, and so on?

Dyson
I don't really know. Perhaps I should say that while I have the greatest respect and admiration for O'Neill, space colonization on that scale isn't entirely to my taste: the big colonies he envisions are a little too hygienic for me. I've done some historical research on the costs of the Mayflower's voyage, and on the Mormons' emigration to Utah, and I think it's possible to go into space on a much smaller scale. A cost on the order of $40,000 per person would be the target to shoot for; in terms of real wages, that would make it comparable to the colonization of America. Unless it's brought down to that level it's not really interesting to me, because otherwise it would be a luxury that only governments could afford. OMNI Where would your Mayflower-style colonists go? Dyson I'd put my money on the asteroids. Dandridge Cole and others suggested using a solar mirror to melt and hollow out an iron asteroid, and in O'Neill's book his homesteaders build their own shells from the minerals available out there. I wouldn't accept either of those as the most sensible course: I think you should find an asteroid which is not iron or nickel, but some kind of soil that you could grow things in. OMNI What do you mean by soil? Dyson Well, we have specimens of meteoritic material called carbonaceous chondrite, which looks like soil -- it's black, crumbly stuff containing a good deal of water; it has enough carbon, nitrogen, oxygen so that there's some hope you could grow vegetables in it, and it's soft enough to dig without using dynamite. OMNI So you think it would be worth looking for an asteroid like that rather than trying to transform a raw stone or metal asteroid? Dyson Yes, if it's to be done on a pioneer basis, you'd jolly well better find a place where you can grow things right away. Otherwise, it's inevitably a much slower and more expensive job. OMNI Is the sunlight at that distance adequate to grow plants? Dyson I think so. Plants are very flexible in their requirements, you know, and they could be genetically altered if it's needed. After all, a lot of things grow very well even in England . . . OMNI What about colonizing the moon? Too much gravity? Dyson That..and it's simply too close to home. Too easy for the tax man to find you. And choosing a place to go is not just a question of freight charges. There have always been minorities who valued their differences and their independence enough to make very great sacrifices, and it seems obvious to me that it's going to happen again. OMNI So you think we may not go in for the big O'Neill type colonies after all? Dyson We may not, but others may. I was in Russia two years ago for a conference on telescopes, and all that anyone there wanted to hear about was O'Neill's ideas. They knew that he and I were both at Princeton, and assumed I could tell them everything about space colonies. The point is that in Russia, they have very little of our current mistrust of technology on the grand scale -- in fact, it fits in very well with their ideas about our relationship to nature. Thousands of engineers working on a giant framework floating in space, that's a picture that excites them very much. I wouldn't be surprised if they choose that. If they do, the historical analogy becomes very strong: the Russians play the role of the Spanish colonists in the New World, and people like me are more like the English, with smaller, scattered, de-centralized colonies. Of course, it took the English much longer to get going, but when we did go, we did a better job. OMNI As for the "going" -- how will that happen? In The Curve of Binding Energy[Ballantine Paperback, 1976] John McPhee quotes you as having hoped that Project Orion would put men on Mars by 1965, Saturn by 1970. Looking back on it today, do you think that "bomb" propulsion should have been followed up? Dyson First, you have to remember that the background against which we're judging Orion has changed dramatically since the nuclear test ban treaty of 1963. At the time we were working on it, we calculated that launching Orion would add no more than one percent to the radiation from atmospheric tests. But that amount would be quite unacceptable under the current ground rules, and rightly so. In some sense, I do regret that we didn't try it -- but history simply passed it by. OMNI What about using chemical rockets to put an Orion-type ship into orbit, then going from there on nuclear explosions? Dyson We did consider that in the later proposals. It would have been disappointing to sacrifice Orion's advantages for the first and most difficult stage . . . and in any case, although the radioactive debris using that approach would not have been nearly so great as that from a ground launch, much of it would still have made its way down into the atmosphere. OMNI Are there any current propulsion ideas as promising as Orion was in its time? Dyson There are several that I think are just as good, if not better. First, there's the ground-based laser system that [physicist] Arthur Kantrowitz has advocated. The ship would simply carry reaction mass -- it could be water -- and the lasers would follow it upward, delivering energy to vaporize the reaction mass. What's nice about the idea is that it would permit you to get into orbit with one stage, costing perhaps$10,000 for a ton of payload. The launching facility could be a "public highway" into space for the kind of small-scale colonization we were talking about; you'd make your reservation and show up with the equipment you'd need wherever you were going -- perhaps not an individual or a single family, but certainly a small group.

OMNI
What would lasers putting out that kind of power do to the air as they passed? It sounds like there'd be a spectacular "Star Wars" beam snapping, crackling, and so on . . .

Dyson
Actually, it wouldn't be like that at all. Remember, air is very transparent, especially at the ten-micron infrared wavelength involved in this scheme. There shouldn't be more than a ten or twenty percent energy loss along the way, and it would be spread over quite a large volume of air. The idea isn't without problems, of course; the air would be heated slightly, which would cause it to expand, so it would tend to defocus the beam. But the biggest problems are in the design of the motor, the structure that receives the laser energy and converts it into heat as efficiently as possible. Unfortunately. no one has built even a prototype yet.

OMNI
Then you foresee no problem as far as the laser itself is concerned; does that mean work on very high-powered lasers is progressing satisfactorily -- for military applications, say?

Dyson
I couldn't say. But there's no reason to use a single giant laser. You could just as easily use a battery of smaller ones, each with a power level that's attainable today.

Another possibility is O'Neill's mass driver. It's an old idea as far as ground launching is concerned, but his proposal to adapt it for thrust in space is new. On the ground, of course, it shares the laser system's chief advantage: you needn't carry along your energy source. There are various ideas on what to use as reaction mass for applications in space. If you get into earth orbit via chemical rockets, for example, you could grind up the empty fuel tanks into powder and use that. Some of it would end up harmlessly in the atmosphere, and the rest would be no significant addition to the ambient dust in the solar system. A liquefied gas would be even better.

The third idea, which would be for travel within the solar system although hardly for launching anything, is our old friend the solar sail. That's a very old idea -- it's in Tsander, writing in 1924, and I wouldn't be surprised if it could be found in Tsiolkovsky even earlier.

OMNI
Has anyone worked that idea out in detail?

Dyson
Not too long ago, NASA invited proposals for a mission to rendezvous with Halley's Comet in 1986, and several groups did studies. It's a terribly hard mission, and chemical rockets can't even begin to get near; it means getting into an orbit going the other way around the sun, a huge velocity change, so the only possibility of doing it at all is with some low-thrust, long-duration propulsion system. So a group of solar-sail enthusiasts at the [NASA] Jet Propulsion Laboratory did a summer study on the mission. They put together a very thorough and really promising proposal, in the "real world," with launch dates and everything. They were working with a Mr. McNeil, a private-enterprise type, who is the inventor of a solar sail he calls the Heliogyro, which is very clever from an engineering point of view and much easier to manage than just a big square piece of foil.

So they put this document together, and when it was finished they went to the JPL management and asked them to recommend to NASA that it be tried. The outcome, and I quote: "The principal limitation preventing the sail from receiving a positive recommendation . . . was the high risk associated with asserting its near-term readiness in the face of absolutely no proof-of-concept tests."

OMNI
Hmmmm . . . who else did they expect to test it?

Dyson
The problem is, of course, that they can't afford to fail. The rules of the game are that you don't take a chance, because if you fail, then probably your whole program gets wiped out.

OMNI
Would a change at the top, say in NASA, open it up to ideas like the solar sail, or laser launching?

Dyson
I don't think the problem is with NASA, but with the whole political system by which government projects are funded. You can't afford to fail, it's as simple as that. Congress just doesn't provide money for things unless they're sure to work. Of course the situation could change, but the change has to be primarily in Congress; I don't think any management at NASA could do very differently from what they're doing at the moment. The trouble is, the scientists aren't interested in new propulsion methods either. They just want the good old reliable rockets; they want to get their stuff into orbit and that's it. So scientists are not going to provide the kind of push that's needed.

OMNI
So O'Neill's approach might be the only way to create a constituency for space colonization?

Dyson
That's not the way I want to go. You see, O'Neill also has this no-risk philosophy very strongly.

OMNI
Then how do you reach Congress?

Dyson
Perhaps you can't. That's the whole question. I'd like to do it with private enterprise. There are people like Gary Hudson, who would like to go into business completely independent of NASA and put stuff into orbit commercially. He believes he can undersell NASA by a factor of ten. Maybe he's right; I wouldn't be surprised. It's just hard getting the customers. Well, as he says, he has lots of people lined up for his second launch.

OMNI
Is it fair to say that for you, the most important aspect of space colonization is that it be cheap, flexible, small-scale?

Dyson
Yes. I'm not altogether fanatical about it, not really a follower of Schumacher. One needs the big enterprises, too . . . there may be things that demand them, and I think it would be a great mistake to be too ideological and say "we must not do it because it's big," which some of my friends tend to do. I merely say that at the moment we're only doing the big expensive stuff, and that's stupid.

OMNI
Short of orbiting enough solar-power satellites to fill all our needs, what do you see as possible answers to our current energy dilemmas? What about fusion?

Dyson
I would have to say that at the moment fusion doesn't look good. Even the best fusion reactor would use ten times as many neutrons to produce a kilowatt of electricity as a fission reactor. Of course, with fission you have a very different set of problems, and we may make the political decision to avoid those -- but on technical and economic grounds alone, fission looks better. I'm very wary of any statement that something can't be done, though -- somebody may come up with a new approach to fusion power tomorrow, and I could be totally wrong.

OMNI
And what about near-term uses of solar power?

Dyson
Right now I'm involved with a solar-energy scheme that Ted Taylor is promoting, I'm just as excited about it as I was about Orion. Ted's a man I'll always be willing to follow. He's always years ahead of the rest of us, and he decided a few years ago that solar energy was the thing to work on. What we're aiming for is a trial here in Princeton of a system centered around a solar pond, a system that would provide heating, cooling, and electricity for a hundred homes, for a capital investment of half a million dollars.

It's a very earthbound, low-technology project -- essentially village technology, something that the Indians, the Thais, the Nigerians, could put to use at once. The basic requirement is a lot of plumbing, and you can find plumbers anywhere -- in fact, you may find better plumbers in the "underdeveloped" countries than here! And the only mass-produced component would be the heat engines, and those you can buy off the shelf right now, cheap and quite efficient.

I don't know if we can do it, but if we can, we'd turn the world upside down; it beats anything.

OMNI:
How far along is the project?

Dyson
Oh, it's nowhere yet -- just Ted's enthusiasm and a few pieces of paper. We've had negotiations with the Department of Energy, but it's just laughable -- you can't even get to the people who matter with anything this small.

OMNI
Even you? Even Taylor?

Dyson
That's right. But the amusing thing is that it really doesn't matter whether we succeed or not, because there are hundreds of other little groups like us around the world. One or another is going to come up with the right idea, and it's no tragedy if ours fails. If it isn't solar ponds, it'll be something else along those lines. There are so many variables -- it's like finding the best way to design a bicycle, lots of details that you only get right after a long time. The most difficult part will no doubt turn out to be figuring out how to dig the ponds cheaply, how to keep children from falling in, and so on . . . !

This is a wild extrapolation. but I think it's worth saying: One of these solar pond systems takes just about the same amount of money and land, per capita, as a highway. If the U.S. were to derive all its energy from solar ponds, it would mean essentially making over again the same kind of investment we've made in our road system -- one percent of the land area, and something like a thousand billion dollars.

OMNI
Presumably a cleaner investment . . .

Dyson
Not all that clean -- -I'm sure there'd be a lot of people who'd object to having these ponds around, and it'd involve many of the same problems as roads. But at least ponds won't stop you from walking from one place to another! Oh, there'd be problems. Sunlight is so abundant, if you can just think up any sensible scheme that will make use of it at five-percent efficiency, you're in. That doesn't mean we should drop fission or the research into fusion, of course.

OMNI
OK, let's assume we get through the next few years, and find sources that will let us keep expanding our energy use. But will we? The thinking behind the Dyson shell, and some of the other "cosmic engineering" projects, seems to be that any advanced civilization will keep doing more of the same thing we've been doing in the last few centuries. Is that a safe assumption?

Dyson
Oh no, that isn't my assumption at all. When I wrote about the possibility of detecting infrared emissions from a shell built around a star, the rules of my game were "What could we detect?" There may be many advanced civilizations that don't handle vast quantities of energy, or that do it in a way we can't imagine and can't detect. But if there are any which do try to make the most of the total output of their stars, we should be able to spot them.

OMNI
As you know, a number of science fiction books and stories have made use of your speculations. Was there a reverse influence -- did fiction influence you?

Dyson
Certainly. As a child I read through all the Jules Verne books I could find, I read Wells, and enjoyed them very much. I read very little else, actually. because I was a poor reader. But the one who set my style of thinking, certainly the most influential, was Olaf Stapledon, with his Starmaker and Last and First Men. I remember they were in Pelican paperbacks. ninepence each. and one day I sat in Paddington Station for two or three hours, reading Starmaker. It seemed to me perfectly obvious that that was the way to think about space and about the future -- that kind of broad scope, that kind of scale.

OMNI
You must be aware that some of your colleagues take a jaundiced view of your ideas about giant trees growing on comets, taking Jupiter apart to build a Dyson shell, and so on. Does it bother you to know that they're out there, muttering about "Dyson's crazy ideas"?

Dyson
Not at all. Keep in mind, I'm also a perfectly respectable physicist, and the speculation is a hobby. It's become well known, but I've grown used to the idea that people very often become famous for accidental reasons. It's amusing to think that someday all my "serious" work will probably be a footnote in a textbook, when everybody remembers what I did on the side . . . ! Anyway, what do I have to lose? I have tenure here, and no one expects much from a theoretical physicist once he's past fifty anyway!

OMNI
In an article some years ago, you pointed out that chemical energy -- the kind in our bodies and brains, the kind we've built a technological civilization on -- is very small, even trivial, compared to the major forms of energy in the universe: gravitational, kinetic, nuclear, and so on. Yet here we are. Is there something about chemical energy to account for that?

Dyson
It is very, very special. The beauty of chemical energy is that it's so enormously flexible, and it can serve so many different purposes at once. It's a good way of storing energy, a good way of releasing it in a controlled fashion, a good way of transferring it from one point to another. I think that's why life makes use of it. There have been ideas, people trying to imagine creatures living inside neutron stars and various other unlikely places. Olaf Stapledon, of course, wrote about living stars --

OMNI
And there's Fred Hoyle's "Black Cloud," an intelligent nebula of gas and dust . . . .

Dyson
All these things may be possible, but we've absolutely no reason to believe it at the moment. What chemical energy has that the other forms don't is versatility, the huge variety of structures, the variety of types of chemical bond. It's a very many-sided thing. But it's hard to know just what is responsible for its "specialness," because we've nothing else yet to compare it with.

OMNI
What's your immediate reaction to, say, Hoyle's black cloud? Does it seem unlikely?

Dyson
I think it's very plausible. In fact, I was thinking about just that in another connection, another of the things I've been working on as a hobby. What is the ultimate fate of living creatures in the universe? There seem to be two possibilities: either we all get fried or we all get frozen. If we all get fried, it's not very interesting. The universe collapses into a big black hole, temperature goes to infinity -- it's all over, nothing you can do. The alternative is much more interesting: that the universe is open and expands forever. The conventional view is that that is also a depressing prospect, because everything gets cold and just disperses. It's Stapledon's "nothing left in the whole cosmos but darkness and the dark whiffs of dust that once were galaxies." But I've been thinking lately -- if the universe is open, could we survive? Could life and intelligence survive? I think probably we could, but it would have to be in the form of a black cloud -- there'll be no possibility for chemical life to survive.

OMNI
Do you mean that we would transform ourselves into such a form, or that we would evolve into it?

Dyson
It's . . . it's hard for us to grasp the time scale involved, it's unimaginably long. As a rule of thumb, it takes a million years to evolve a new species, ten million for a new genus, one hundred million for a class, a billion for a phylum . . . and that's about as far as your imagination can go. In five billion years or less, we've evolved from some sort of primordial slime into human beings . . . what would happen in another ten billion years? It's just utterly impossible to conceive of ourselves changing as drastically as that over and over again, but . . . I think all you can say is that the material form that life would take on that kind of time scale is completely open. To change from a human being to a black cloud may seem a big order, but it's the kind of change you'd expect anyway over billions of years. There's all the time in the world for evolution before the sun runs out of fuel.

What I envisage as the structural unit of such a creature is simply dust grains, probably made of iron or some convenient stuff, probably charged and working on each other with electric and magnetic forces. One can imagine enormously complex structures built out of these things. What would correspond to a muscle, or a nerve synapse? I haven't the faintest idea . . . it's an open-ended system, in the same way as the organic fluids we're made of, and the electromagnetic forces would give you a means of tying it together, coordinating it. It could be just as complex, even more complex than what we see around us now.

OMNI
Then how do we manage to understand the universe at all? Do you agree with Carl Sagan, for example, that we find the mathematics of gravitation so simple and elegant because natural selection eliminates the apes who couldn't understand?

Dyson
Not at all. For apes to come out of the trees, and change in the direction of being able to write down Maxwell's equations . . . I don't think you can explain that by natural selection at all. It's just a miracle.

OMNI
You have also written that "as we look out into the universe and identify the many accidents of physics and astronomy that have worked together to our benefit, it almost seems as if the universe must in some sense have known that we were coming." Is that a playful suggestion?

Dyson
It's not playful at all.

OMNI
Then we seem to be talking about sentiments that most people would consider religious. Are they religious for you?

Dyson
Oh yes. It's always difficult to mix science and religion without making a fool of oneself -- in fact, it's probably impossible, and one is probably very unwise even to try . . .

OMNI
Well, let's say that the pressure of this interview is forcing you out on a limb. As we all know, the dominant tendency in modern science has been to assert that we occupy no privileged place, that the universe does not care, that science and religion don't mix. Where do you fit into those ideas?

Dyson
The tendency you're talking about is a modern one, not old. I think it became almost a dogma only with the fight for acceptance of Darwinism, Huxley versus Bishop Wilberforce, and so on. Before the nineteenth century, scientists were not ashamed of being religious, but since Darwin, it's been taboo. The biologists are still fighting Wilberforce. If you look now, the view that everything is due to chance and to little bits of molecular clockwork is mostly propounded by biologists, particularly people like Jacques Monod -- whereas the physicists have become far more skeptical about that. If you actually look at the way modern physics is going, it's very far from that. Yes, it's the biologists who've made it so hard to talk about these things.

I was reading recently a magnificent book by Thomas Wright, written about 1750, when these inhibitions didn't exist at all. Wright was the discoverer of galaxies, you know. So I'd like to read from that -- it's easier to say these things by quoting others. He's talking about how many inhabited worlds there are, and he writes:

"In this great celestial creation, the catastrophe of a world such as ours, or even the total dissolution of a system of worlds, may possibly be no more to the great Author of Nature than the most common accident of life with us. And in all probability such final and general doomsdays may be as frequent there as even Birthdays or Mortality with us upon the earth. This idea has something so Cheerful in it that I own I can never look upon the stars without wondering that the whole world does not become astronomers; and that men, endowed with sense and reason, should neglect a science that they are naturally so much interested in, and so capable of enlarging the understanding, as next to a Demonstration must convince them of their immortality, and reconcieve them to all those little Difficulties incident to human nature without the least Anxiety."

OMNI
That's the long view indeed . . . even at the Institute for Advanced Studies. How much do you discuss your "hobby" with your colleagues here?

Dyson
This place is a motel, and people change from year to year. That's what I like about being here, a fresh crowd every year. The number of permanent people is very small, so most of the time I'm talking to visiting members. In the School of Physics we are, generally speaking, very serious; the young people are highly specialized and want to talk about their professional work, so the people I talk to about speculative things are usually historians and sociologists and anthropologists and such people. One of the most interesting was a Brandeis professor named Frank Manuel, who's interested in the concept of Utopia and its history, and how it has been transformed through the centuries. Actually, he was studying me as an example of the modern utopian, so we had long sessions in which I would talk about space colonies and so on, and he would say Ah yes, that came out of such-and-such a German writer of the seventeenth century that I'd never heard of.

OMNI
Do you think that "a modern utopian" is a good description of you?

Dyson
Yes, in the sense of someone who imagines ideal societies. I certainly am.

OMNI
And the colonization of space will open up chances for new Utopias, many different societies in the asteroids.

Dyson
Even many different kinds of humanity. I don't think humanity is going to be a single species much longer -- maybe because of divergent evolution as we expand into space, and maybe sooner than that via genetic manipulation. Unless you enforce a total prohibition on genetic research -- unless you effectively outlaw the study of biology -- I think it's inevitable that people are going to want to make their children better than themselves, and the techniques to do that will be available in the next century.

I've recently been on a local committee formed to consider Princeton University's plans for recombinant-DNA research. Our official responsibility was just to assess the potential danger from a laboratory accident that might release dangerous organisms, but I found that everyone on the committee was more concerned about the steps beyond that. They were concerned with "what are they going to do to us?" It surprised me, because I had thought that only I worried about these things. And I think their concern is much more realistic than some of the comforting reassurances about how far away human genetic engineering is. It's nearer than we imagine.

And beyond that, there's a continuing social strain that can only increase. It's a tension between the idea that all men are brothers and the idea that every individual or group should be free to do its own thing. You see it in racial problems, in national and ideological conflicts. Conceivably, if you give people the choice of being brothers or going out into space, that could provide the impetus for colonization. It's very striking how often in the past a journey that looked like exile from one point of view has turned out to be an opportunity from another.

11. ### SeekerOfTruthUnemployed, but LookingRegistered Senior Member

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358

But I am not sure it answers my question of Why?

12. ### RiomacleodRegistered Senior Member

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301
Wouldn't adding a sphere like that alter the rotation of the system involved?

13. ### SeekerOfTruthUnemployed, but LookingRegistered Senior Member

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358
I would expect so. Also, let's assume that you create a sphere that is the radius of the earth's orbit and you want to live on the inside. You would need to be able to generate gravity in order to live on the inside. If you can do that, why do you need to harness all of the energy of the sun?

Also, imagine the mass of a sphere that had a radius of the earth's orbit. Assume that it is at least 2 miles thick to avoid any problems with stray comets pucturing a hole in it. How much mass does it have and wouldn't the mass alone be enough to effect the sun's dynamics?

14. ### HolyRegistered Senior Member

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74
That sphere would be an awesome piece of equipment, where can I buy one? I believe the use of such a sphere would be to harness the total solar energy.

Perhaps one should construct the sphere with the following properties?
- A wide slab of the inside of the sphere should be constructed for living purpose. The sphere could then rotate to create a centripetal force instead of (or combined with) gravitational force.
- The rest of the sphere (the sides of the slab) could be created to extract the energy from solar flow.
- One would like to have an exit from the sphere for other cool sci-fi purposes.

I believe there once was a Star Trek episode with such a sphere.

A problem:
Would the mass of the sphere smudge the sun until the gasses and material of the sun would occupy the total inside of the sphere (since the sphere would have a significant mass that probably would attract the content of the star).

15. ### wet1WandererRegistered Senior Member

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The M. C. Escher's Concentric Rinds intersect, sometimes three rings at a juncture, sometimes four, Escher's print looks like a multi-ringworld system.

A fanciful Dyson Sphere with face imposed on it.

Layout of Dyson Sphere orbital space.

Dyson Spheres supply tremendous living space and energy collection as was in the article supplied by Chagur. Having already read the concepts in science fiction novels such as Ringworld series, I am familiar with the idea. One of the reasons that some civilizations would build such an object would be if their reproduction rate were extremely high. Such a civilization would probably be continuously at war for resources and living space. This would buy them time if they had not discovered some method of birth control. It would be hard for me to imagine such a race that could move such masses and not be able to do bioengineering. Another possibility would be that if they occupied a solar system that was a rogue system. One that was leaving all other galaxies and putting tremendous distances between that race and any possibility of being able to move to other systems. It would probably take almost all of the mass in the solar system, such as ours, to complete a full sphere. The problems in dissembling a planet the size of Jupiter alone would be something that is monumental in task size.

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16. ### SeekerOfTruthUnemployed, but LookingRegistered Senior Member

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If you rotated the sphere to create an "artificial" gravity you could then have different zones of living because the rotation of the sphere would have different radial accellerations when moving from the "equator" of the sphere towards one of the poles. The poles are defined as the axis of rotation. Hmmm, have to think about this one for a while.

If you changed the sphere into a hoola hoop with raised sides you would have a "Ringworld" another object that Larry Niven wrote several books about.

Yes, Star Trek, the Next Generation, did have an episode where they ran into a Dyson Sphere. It was the one in which they found "Scotty" from the original series.

As to the effects on the sun, good question. I haven't done the math, but I guess it would depend on the total mass of the sphere and how much radial gravitational attraction the sun would experience from any given point on the sphere.

17. ### wet1WandererRegistered Senior Member

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These figures are already worked out. Not only can you have a Dyson Sphere, you can have a Dyson bubble. The Dyson Bubble is held inflated by the stellar radation providing push against the surface. The star will not be affected by the mass of the sphere as far as rotational instability goes. The sphere can be adjusted in its orbital positions, it is not locked to permanent fixed unchangable position. Much the same as a space craft can be changed in its orbital position.

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19. ### Vicker 2000Registered Member

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Here's some nice pictures of how you would contruct a Dyson Sphere for all those who are interested. I would share the plans that my race used when we were building our's, but I would get in big trouble with my government if I did that. =)

http://users.javanet.com/~jasp/dyson/

20. ### TegUnknown CitizenRegistered Senior Member

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Larry Niven refers to one of these in Ringworld. The problem with one of these structures is that it would be very vulnerable to asteroid hits. Some sort of protective barrier or defense system would be required. Overall an interesting idea yet completely unreasonable. Terraforming would be more practicle.

21. ### Adam§Þ@ç€ MØnk€¥Registered Senior Member

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A lot of theories lately about rogue planets wandering through space, thrown away from stars; and a claim recently that there are heaps more brown dwarfs and such than previously thought. If ever we have the technology to make a dyson sphere, I guess we could use them for material.

As for gravity, wouldn't we have 1G if the material was dense enough? If not, give it a bit of a spin.

I think if it was done, you'd have the entire northern and southern pole areas used only for energy collection, not populated at all. Stars tend to have those great big jets of garbage shooting out their poles, can't remember what they're called.

I don't see the need for such things. By the time we have that capability, we'll probably be more interested in zooming around the universe looking at all the interesting stuff. Why be stuck inside a sphere doing the same old same old?

22. ### TegUnknown CitizenRegistered Senior Member

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I think there exists an assumption that eventually science catches up with science fiction. We have been theorizing about traveling about the universe and colonizing other worlds. I think first we should worry about the world we are on. It has O2 and H2O. Not many other planets can say this.

By our current theories faster than light travle is impossible. I think that concentrating on an Earth- based solution makes more sense. What does it say that we haven't been able to coexist with the planet we live on?

Think about this one: perhaps this Dyson sphere is an easier trick than we know. Then how many of those dead stars might just be enclosed by a Dyson sphere? (Just a little something to ponder)

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Dyson

Engineer it.