The Dyson Sphere is roughly the same age as I am. Of course, the Dyson sphere is roughly 1 A.U. in radius and would be the most tremendous achievement of any society producing it, and similar claims are never made about me, at least not when I am sober. On the other hand, as of this writing, I actually exist. Advantage: Enge.
I’m not sure the Dyson Sphere concept makes any sense anyway. If you had the energy and resources to build it, you wouldn’t need it.
[Discoverblog item seen via james_nicoll.]
How so? The classic original swarm can be built up gradually and provides a payoff for the investment the whole way through the project.
If we’re talking about a sufficient area of collectors to effectively catch all of the sun’s light at the radius of earth’s orbit, eventually we’re talking about breaking up planetary masses and moving them about. The increments involved at that stage would have to be very large. Apart from the repellent destructiveness of this process, the energies deployed would be titanic. If you have that much energy to deploy, it seems futile to deploy it just to get more energy.
[edited for clarity–maybe not successfully]
the energies deployed would be titanic
Yes. And we all know what happened to that! At least those of us who saw the movie do.
Peadar the disignorant
Okay, if Kate Winslet is involved, I’m for it. Otherwise not.
Only if we can drown Leonardo DiCaprio again…
The tagline could be: In space, no one can hear you drown… Something like that.
I have to admit I thought DiCaprio was good in Man in the Iron Mask, though.
If we’re talking about a sufficient area of collectors to effectively catch all of the sun’s light at the radius of earth’s orbit, eventually we’re talking about breaking up planetary masses and moving them about.
I actually think that Dyson swarms will mostly be built much farther inward, and furthermore that we’re likely to keep the ecliptic clear as much as possible, in order to allow them to coexist with natural planets.
If all you want is a swarm of collectors and radiators then you might be able to get by (at least in the initial stages) with the material in asteroid belt, which works out to about seven grams of material per square meter for a 1 AU swarm.
One of the nice things about partial swarms is that they give one the ability to slowly increase the human ability to dismantle otherwise useless bodies. The comets and asteroids come pre-crumbled so we’d use them first and with the energy we get from those solar power plants we could dismantle objects like moons. Once the moons are used up, we can turn our attention to solid planets like Mars and Mercury and once they are gone, Venus will be on the chopping block.
A full sized Dyson sphere controlling the output of the sun can take a Earth sized planet apart in about a week if that’s the only thing it uses its power on. The gas giants remain somewhat problematio: it would take at least six years to take Jupiter apart even if the only use you had for the sun’s energy was dismantling planets and most of it is largely useless hydrogen anyway.
Dyson spheres mostly make sense from the POV of very long-term energy conservation. The big assumption underlying them is that we will still need solar energy at that point — it’s my guess that we won’t. OTOH, I could see Dyson swarms just growing, like Topsy, no central plan required other than traffic control regulations.
Dyson spheres
I’ve never been clear on what use a society would have for 100% of a star’s energy output. If they’re living inside the Dyson Sphere, the habital area would still have to be limited — I’m assuming that you spin the sphere to get 1-g, but seems to me that only a smallish percentage would get what you might call “straight-down” gravity, the direction of gravity inclining further and further from the vertical the closer you get to the sphere’s axis of rotation. They might have gravity control, of course, but if you have that, seems it would be simpler to use your resources to build tens of thousands of little worldlets — 100-km radius with 1-g and standard atmosphere — rather than putting all your eggs in one enormous basket.
If, on the other hand, you assume that they have technologies on par with Doc Smith in “Skylark DuQuesne,” perhaps you could simply build a Dyson Sphere about stars in solar systems without life, as many as you like, and them somehow beam the power from thousands of stars to wherever it’s needed in this or other galaxies. (It’s so fun, ignoring inconvenient laws of physics!)
But as always, the main thing that Dyson Spheres do for me is give me the feeling that I need to go back and read “Ringworld” yet again.
Re: Dyson spheres
http://en.wikipedia.org/wiki/James_Nicoll#Nicoll-Dyson_Laser
Re: Dyson spheres
So you see, piping energy from energy rich regions to energy poor regions is do-able.
Re: Dyson spheres
Now there’s a laser-pointer with some authority.
Re: Dyson spheres
Dyson intended the sphere to be made of many many independently orbiting solar collectors and habitats, not one shell (In fact in one series of letters he mentions offhandedly the stabilities issues involved in solid shells and rings).
No-one ever built anything to show off, ever, did they?
🙂
You read Walter Jon Williams’ Implied Spaces yet?
Haven’t read the WJW… but I have to admit, in the back of my mind, as I framed my practical objection to the sphere, I was thinking But suppose they’re impractical?
So maybe I could see a Dyson Pyramid, as it were, easier than a Dyson Sphere.
Not sure impractical bothers anyone.
We have big human headed lions
opera houses that sail
big meccano towers in Paris
leaning bits of Italy
space needles
chicks with crowns and torches
not to mention Las Vegas
if people are people and had that sort of ability, be pretty easy to see some way over the top stellar sized crap being hung out there. 🙂
Possibly so–there are practical limits even on impractical projects, though. The Eiffel Tower can’t have taken a significant amount of France’s resources to build. If a society got to the point where building a Dyson Sphere was a relatively trivial effort, I’m not sure they would be people anymore, exactly.
The thing is, with a swarm you don’t need to set out to do it all at once. You just keep adding elements a little at a time over a long time and at the end of it you have trillions of collectors blocking most of the energy from the star.
The Darien project in the late 17th century is a nice example of what happens when organizations tackle projects whose costs are large compared to the economy (or rather, what happens when those projects fail).
Interesting! This suggests a story–the fallout from a failed attempt to build a Dyson sphere (or another one of these mega-projects). For best effect, the afflicted system should have some mix of rivalry and alliance with the interstellar community it appeals to for help. There’d be scope for action by politicians, engineers & scientists, and daring space pilots. The stakes: the survival of the inhabited worlds–or their nonsurvival (if their rivals in the interstellar community are sufficiently ruthless).
>>I’m not sure the Dyson Sphere concept makes any sense anyway. If you had the energy and resources to build it, you wouldn’t need it.<<
Well, unless the superintelligent race, say, accidentally blows up a neighbor’s planet (or entire system) and they build the sphere as both apology and resettlement…:)
Or they have some sort of mysterious/nefarious purpose (as in Bob Shaw’s Orbitsville and its sequel).
The beings in Farthest Star wanted an intergalactic space ship, so they built one four times the mass of the sun and launched it at 1/6th C….
I’d forgotten that one. That was a historic Dyson sphere for me, too: Part One of “The Org’s Egg” was in the first issue of Galaxy I ever bought.
It takes a significant fraction of the power output of all the stars in a galaxy for years to get a ship that size up to speed.
Not sure what the peak output on a galactic scale jet is, though.