... Um, how about "No?"

Now, which type of Dyson Sphere are we talking? There are more than one. Dyson's original sphere design is not a true sphere, but a bunch of what amounts to miniature ships orbitting a sun, getting energy from it. The version we typically see in Scifi is a version that completely encloses a star... and typically doesn't survive very long the moment a star goes nova.

The problem is the fact that, if we had the resources, we could begin buildomg a Dyson Sphere now. The other problem is the building of one, even for the typical star, would take longer than artificially creating a continent three times the size of North American in empty ocean. Even with the ability to snap your fingers and instantly transmute stellar gases into fully-functional buildings, it would still take several hundred years to build a sphere. The ship option that Dyson originally came up with is a lot more practical, but still so expensive that it might not be worth it.

And, while stars do last millions and billions of years, most of them are already billions of years old by the time they would be reached. Some of them are as old as 12 billion years. By the time you're finally finished building the sphere, it may be just in time for the star to go nova anyway. If there is an actual sphere around, it was probably built by the Dreadlords or someone else from around that time.

To be honest, the level of technology this game employs makes a sphere to be an unviable option for inclusion. Pretty much, with the level of technology you are talking, a person having enough understanding of physics to create a fireball with pure will and have it orbitting their hand would be acceptable. We're talking a level of understanding where the kind of spellcasting found in myths could actually be done, and the people doing it could telepathically transmit the mathematics that back it up. Hell, if we're going to do Dyson Spheres of the completely enclosed kind, we might as well make the Warcraft In Space.

For the technology rate of this game, that means you should be able to research a Technological Victory with only one planet, one research building, and only 1% of your funding going to research before you even reach the halfway point of building a sphere.

Even with an interstellar empire, you're talking about hundreds of years. And, no, it wouldn't take us hundreds of years right now. It would take us three billion years. For Sol, you're only talking about building something with a mass approximately equal to Jupiter and Saturn combined. Including the moons and rings. And that's building it using the least amount of materials you possibly can. It would be easier and cost you less time and resources to build an entire planet from scratch.

Oh, and if the space stations are as huge as I think they are, it wouldn't take 10 or 20 constructors. It would take 40,000 (or more). You could probably do it in the alrgest galactic maps, assuming you started immediately, turned off all of the victory options, and left one empire that you could get along with alone for a couple months (real time). Of course, it's really hard to tell with the way proportions are handled in this game.

Now, if you go for the Dyson Sphere as Dyson imagined it, you could probably build the sucker in 9 weeks and with only 5 constructors (if you even need that many). However, the original type of the Dyson Sphere is a moot point for GalCiv, simply because humans have already produced it's replacement. The original type of Dyson Sphere is just a way to take advantage of stars to provide power for planetary settlements. You are, in essense, just capturing energy thrown off by the star and routing it to a nearby planet. It's not a true sphere, as the ships are in constant movement and often leave behind holes. In fact, I think I saw one guy touting it as an eventual solution to all of Earth's energy problems.

Now, keeping all of that in mind, keep in mind Nivan suggested an alternate solution: A ringworld (Bungie used this idea for the game Halo). It's cheaper, far less resource-intensive, and can be done much faster than a Dyson Sphere. Plus, if of the right size, can support a population in the trillions. It's also within the technology range that GalCiv 2 uses.

If you are talking earth normal levels of radiation density, the radius would be roughly the size of the earth's orbit ~93 million miles. This comes out to a surface area of roughly 108 quadrillion (10^15) square miles. (4*pi*r^2) The earth has a surface area of (including oceans) roughly 197 million (10^6) square miles. (proportion water to land ~ 70%/30%) So the scale of a complete Dyson sphere is roughly 500 million earths.

partial quote from wisegeek.com

The original proposal for a Dyson sphere was not for a solid sphere, but a collection of ~10^5 objects which collectively absorb the bulk of the star's solar energy. Sometimes called a "Dyson swarm," this would allow the incremental construction of the system, with subcomponents orbiting the star independently. From the outside, such a swarm would appear black, emitting only infrared radiation. Some of our orbiting infrared telescopes have been searching for such bodies as Dyson spheres or swarms for decades, with no luck. If reflectors were used on the interior of the objects, the radiant energy might be directed only one way, making it hard to detect from a distance. Preliminary calculations have shown that our solar system contains enough rigid matter to construct a Dyson swarm, but probably not a rigid Dyson sphere, which would have to be about a million km (600,000 miles) thick to be stable.

Why are you all debating the real life consequences/possibilities of a dyson sphere? This game is not real life, a dyson sphere would be nothing more than a game mechanic and could be appropriately changed and scaled. If you want to get into impossibilies how do the hyperdrives work? Negative matter? Rare and extremely difficult (I would say just as difficult as building a dyson sphere) to accumulate enough to use. Wormholes? Certain things in games are fudged over, and "if' they included a dyson sphere I can most assuredly tell you it would be fudged all over.

Well i don't know. The game can fudge some pretty hard to believe things, but that's only because they've been paved over. Hyperdrives, wormholes, all of this has been told over and over by Starwars (i love that show) and Startrek (the older series were better then the new one).

But a Gigantic base as big as a star has only been seen once or twice. (Startrek: The next generation Season 5, episode... something or other i can't recall) and isn't quite as fudgeable. Everything seems phesable because the programers can change the laws of physics at this advanced level because we aren't really quite sure it can't happen. Wormholes are rare, but just because we haven't seen one doesn't mean they aren't there, and there's alota space out there we haven't seen.

However a gigantic Star covering base would be a bit hard to fudge. Even with shields to deal with the radiation, Construction ships with orbital replicators to create them, advanced antigravity and rotation controlto ofset the stars actual gravity, and maybe requiring to destroy 1 or 2 planets in the system to provide the base for the soil on or in the sphere, and many constructors bringing in materials to transmute, it would still be a bit hard to believe, they're just to dang BIG. I think that if bungie ever puts in a Dyson Sphere there's no way we're gonna be the ones to build it. It'd be a rare and extremely valuable relic from the Arnorians or dreadlords. They were so advanced, and so ancient (think: Q-continuum) that they could easily have constructed a number of them throughout the galaxy, perhaps to take advantage of strategic positions, or whatnot. Even if it's actually put in, it might not even be shown as a real planetoid, but instead a random event like a sphere phasing into our dimension but fading out soon, etc.

in conclusion: Practical phesability without fudging: Low
Practical phesability with fudging: Easy as pie

Azrune...In the fiction of a Dyson Sphere it is built at the radius of habitation from a star; just as the Earth is habitabal and safe at it's distance from the sun. The inner surface is used like billions of planets. Gravity is from rotation, "gravity generators/plates", neutronium plates, or even the mass/gravity of the structure.

In Space Empires IV and the soon to be released Space Empires V there are both Ringworlds and "Sphereworlds". They are highly advanced, late game technologies that can be constructed while the former planets remain. It is assumed that this advanced of a civilization can heat a planet adequatly. This is all in an area of research called "Stellar Manipulation".

mute

Sorry to correct, but the word you want is "moot"