33 replies to this topic

[TheMacGuffin]

Waspie_Dwarf, on 08 October 2012 - 10:12 PM, said:

It would be even nicer if it was on topic.

All right, I shall say no more about it.  It's just one of those things that gets posted on the Internet and forgotten.

[Waspie_Dwarf]

TheMacGuffin, on 08 October 2012 - 11:31 PM, said:

All right, I shall say no more about it.  It's just one of those things that gets posted on the Internet and forgotten.

It doesn't need to be forgotten, there are plenty of places on this site to ask your question, you shouldn't need to be told that a topic about Dyson Sphere's is not one of them.

[TheMacGuffin]

Waspie_Dwarf, on 08 October 2012 - 11:53 PM, said:

It doesn't need to be forgotten, there are plenty of places on this site to ask your question, you shouldn't need to be told that a topic about Dyson Sphere's is not one of them.

You will see me no more on here, Waspie.

Edited by TheMacGuffin, 09 October 2012 - 12:17 AM.

[StarMountainKid]

I think any ideas we can come up with to try to discover extraterrestrial life is worth trying.

[Sundew]

Perhaps I am missing something here, but we are not talking about a planet sized sphere here, as difficult as that would be. We are talking about a sphere the size of a planet's orbit, if one is talking about encasing a star. Think about that: all the material on all the rocky planets, moons, etcetera, in our solar system would not amount to enough material to encase our sun even one meter outside of it's outer layer. Now expand that out to the orbit of the Earth (or even Mercury) and you begin to see the unreality of the problem. And if there was truly a space fairing civilization who had the ability to collect material from outside of their home star system, would it not be far easier to colonize other stellar systems then to build something of this magnitude?

Look, I am always telling people don't discount science fiction because so much of what was once fiction has become scientific fact. But something on this scale seems total unrealistic at best. There is a cost/benefit ratio and the cost would be off the charts.

And you thought we have a debt and deficit crisis!

[DieChecker]

Though the theory of a Dyson Sphere is logical, it probably could not be built without importing materials. So, I think they would be incredibly rare based on that alone. But, perhaps the universe is filled with solar systems that have hundreds of planets....

So looking for the Dyson Sphere would be looking for the waste heat, right? If we assume that the civilization that builds a Dyson Sphere is capable of good efficiency, then you're not going to see any excess heat/IR. All the solar output will be collected. At best with poor effiency the Dyson Sphere would look like a Red Giant, and with decent effiency you'll not see it at all out past a couple parsecs, or perhaps not till you bump into it. Looking for them in the Milky Way and Andromeda would be wasteful enough, but how do they plan to find Dyson Spheres in other galaxys when their output will be less then a white dwarf?

[bison]

The prospect of using solar system material to create a 'shell' two astronomical units in diameter, that could intercept essentially all solar output has been looked into, and was found to be physically ( if not currently technically) possible. Freeman Dyson was a real physicist, and was certainly capable of doing the math.
   A Dyson Sphere around a star similar to out own would make available about 40 billion times as much energy as we currently have at our disposal. Even a remarkably high level of efficiency in reclaiming waste heat could well leave a remnant that we might detect.  The same would apply to any technical civilization controlling a similar amount of energy, by whatever means. The consideration of diminishing returns in adding increased efficiency vs. the cost of doing so presumably prevails everywhere.

[Twin Peaks]

Perhaps Dyson spheres are invisible. I suspect that finding them would require some other kind of detection. Aliens probably dont even need to cover the entire sun. Imagine how vast a civilization must be to actually need the entire suns energy. Just make a small array that absorbs some of the sun. The star Epsilon Aurigae dims every 27 years due to a mysterious dark object eclipsing it periodically. That is a good example of what might be a partial type of sun energy absorber.

Edited by Twin Peaks, 09 October 2012 - 06:19 PM.

[Parsec]

Ok, let's say that an alien civilization builds a Dyson sphere. And then? How do they transmit the energy collected to their home planet? Through wires Astronimical Units long?
Or maybe with energon cubes?




Maybe we'll find Cybertron?

[bison]

The original idea, I believe, was that people would live on the inside of the 'shell' (more properly a spherical swarm of objects) and that the energy would be incident on this star-ward facing  surface area, ready for immediate use.
   The idea that the Epsilon Aurigae star system is an example of a incomplete, or partial 'shell' of this sort is interesting, but has certain problems. The best current information on this system seems to indicate that  the eclipsed body is an F0 star  which has gone off the main sequence, swollen to gigantic size, and is near the end of its stellar life. The eclipsing body is thought to be a B star, with something large and diffuse surrounding it. Could this surround be a Dyson Sphere or a partial version of one? The fact that an F0 star has a lifetime of only about 4 billion years argues against there having been enough time for a technical civilization to have developed there. The lifetime of a B star is very much shorter.
     I wouldn't think this a very promising system for colonization from another star system, either, given the instability of the F star. A civilization capable of constructing even a partial Dyson Sphere might also be able to re-engineer a star, to prevent it going off the main sequence, but that doesn't appear to have been done here.

[None of the above]

Sundew, on 09 October 2012 - 02:02 AM, said:

Perhaps I am missing something here, but we are not talking about a planet sized sphere here, as difficult as that would be. We are talking about a sphere the size of a planet's orbit, if one is talking about encasing a star. Think about that: all the material on all the rocky planets, moons, etcetera, in our solar system would not amount to enough material to encase our sun even one meter outside of it's outer layer. Now expand that out to the orbit of the Earth (or even Mercury) and you begin to see the unreality of the problem. And if there was truly a space fairing civilization who had the ability to collect material from outside of their home star system, would it not be far easier to colonize other stellar systems then to build something of this magnitude?

Look, I am always telling people don't discount science fiction because so much of what was once fiction has become scientific fact. But something on this scale seems total unrealistic at best. There is a cost/benefit ratio and the cost would be off the charts.

And you thought we have a debt and deficit crisis!

I was just about to start a very similar reply and thought I better make sure nobody neat me to it.
You did

Developing the technology to encase a star seems like fun in Star Trek, but in reality any civilisation with that kind of technology and that level of available resources wouldn't need to waste them creating a Dyson Sphere.

[Sundew]

Atlantia, on 10 October 2012 - 07:56 PM, said:

I was just about to start a very similar reply and thought I better make sure nobody neat me to it.
You did

Developing the technology to encase a star seems like fun in Star Trek, but in reality any civilisation with that kind of technology and that level of available resources wouldn't need to waste them creating a Dyson Sphere.

Well, not trying to rain on anyone's parade, just seems so illogical or unlikely given the cost of bring materials from outside of a solar system to build such a structure. Yes when finished you might have unlimited energy, but it would take nearly unlimited energy to build it in the first place!

[MidKn13ght]

I thought there was a movie based on this scenerio... and they did make a dyson type energy absorber to save earth??? Either way dont think we would have to shell the whole sun.... a good size "charging" station i think would be just as affective. Dont think we need all the solar power at once, just in bursts maybe.... intresting though.... but i would think if this alien race had the ability to make such a thing, wouldnt it be easier to locate another planet to inhabit????

Edited by MidKn13ght, 12 October 2012 - 06:00 PM.

[bison]

Human use of energy has grown exponentially over time.  We use about 115 times more than our remote hunter/gatherer ancestors, before they discovered fire. It doesn't seem likely that even someone from the Renaissance, fresh with the idea of human progress, could have believed that people, 600 years hence, would use 12 times as much energy as they did; what use they could possibly make of it, or how they could afford it. Nevertheless, we manage to do so, and even to foresee the need for more energy, and the possibility of producing it. It seems risky to try to place limits on what may be possible in the future.

[Hawkin]

I saw something like this on an episode of Star Trek TNG where the Enterprise found a sun with a Dyson Sphere and Scotty
(James Doohan) crashed on it.