Dyson Spheres revisited

[flykiller]

don't need a dyson sphere for any of that. not sure the dyson sphere would even be relevant.

was thinking about "travelling" after reading that post. in traveller one travels from one location to another a vast distance away, and correspondingly different - in nature, in culture, in type, etc. the game of traveller itself reflects that notion of travel. but is travelling within a dyson sphere "travel"?

 

[Barrel]

"What we think are many red dwarf stars are actually the residual heat signatures radiating from the outside of the spheres.

that's a whole lotta ET's ...."

Thinking about it now, without having the book in front of me, I think he said red giants not red dwarfs. That would make more sense, with the diameter of the DS about the diameter of a red giant.

 

[Nathan Brazil]

There is a Dyson Sphere campaign available from West End Games called Septimus for free over at Drivethru. It uses the OpenD6 (original Star Wars) rules which are also free.

With such a large area, you could have "culture of the week" like early Star Trek TNG, without the space trsvel. There were a few television show in the 1970's that had that idea

One was 1977's The Fantastic Journey, where the characters were from different planets and times, stuck on an some island in the Bermuda Triangle. Each week the group would travel through a network of invisible teleporters allegedly all on the same island but in different eras of time.

Lost in the Devil's Triangle, trapped in a dimension with beings from the future and from other worlds, a party of adventurers journeys through zones of time back to their own time. Varian, a man from the 23rd century, possessing awesome powers. From 1977, Fred, a young doctor just out of medical school. Scott Jordan, the 13-year-old son of a famous scientist. Liana, daughter of an Atlantean father and an extraterrestrial mother. And Jonathan Willaway, rebel scientist from the 1960s. Together they face the frightening unknown on...the fantastic journey.

It was pretty bad show, but hey Roddy McDowell was cool as a more calculating, competent and brave "Doctor Smith" character.

There was also the Ringworld RPG based off of Larry Niven's Known Space books and

 

[Blue Ghost]

don't need a dyson sphere for any of that. not sure the dyson sphere would even be relevant.

was thinking about "travelling" after reading that post. in traveller one travels from one location to another a vast distance away, and correspondingly different - in nature, in culture, in type, etc. the game of traveller itself reflects that notion of travel. but is travelling within a dyson sphere "travel"?

Well, it would be high magic, possibly with cultist overtones; i.e. dark elves and the like. I think it would be interesting.

 

[Blue Ghost]

Interesting. I don't ever recall a show called "Fantastic Journey". I do recall Steven Spielberg's "Amazing Stories", which kind of had that vibe. I think they even did a Car Wars episode one time.

 

[flykiller]

There were a few television show in the 1970's that had that idea

there was one where earth had been destroyed but had loaded up a colony ship with several huge isolated self-contained eco-spheres with examples of earth culture, and the ship had malfunctioned and a team of engineers was transiting each culture in an attempt to reach engineering and fix the problem and save all the self-centered cultures. multiply that by a billion and it might approach a dyson sphere ....

reminds me of chairman mao when asked to evaluate his ultimate influence on china. "I've managed to change a few places in the vicinity of beijing ...."

 

[Blue Ghost]

Why would a DS have to be fully populated?

 

[Nathan Brazil]

there was one where earth had been destroyed but had loaded up a colony ship with several huge isolated self-contained eco-spheres with examples of earth culture, and the ship had malfunctioned and a team of engineers was transiting each culture in an attempt to reach engineering and fix the problem and save all the self-centered cultures.

That was "The Starlost" and they were not engineers. They from an Amish-like ecosphere. The colony ship went off-course. Their pod and many others forgot they were on a ship. The main character learned the secret and was ostracized from the pod by the elders. The colony ship going to crash into a star in a few Earth standard years unless they could get to a place called "The Bridge".
It came out in late 1973, which has often led me to wonder about the similarities between it Metamorphosis Alpha which came out 1974.
Harlan Ellison was involved in it, and like his rep, got pissed off and disavowed it. Kier Dullea (of 2001: A Space Oddyssey) was the star.

 

[aramis]

Why would a DS have to be fully populated?

it would be nearly impossible to populate to a notable density in any reasonable lifetime.

Plus the issues with stability.

And that Dyson's proposal is actually a swarm, not a single sphere...

 

[Blue Ghost]

Yeah, I think those were mentioned in the thread. I think it largely depends on the tech level. A 1960s civilization (tech 5 or tech 6) might have issues with structural integrity. But it would be interesting for players to visit a kind of vaccuum tube or transistors you can hold in your fingers kind of civilization. It would be an odd mix, but interesting.

I guess the practical issues, to me, get pushed aside when considering them for a game environment. My real issue it with heat build up, and in the case of a ring world, water and atmospheric spill off. What happens when you get to the edge or the "entry port" of a sphere or ring?

I don't know. I think it's still worth exploring for a home-brew gaming session.

 

[kilemall]

That was "The Starlost" and they were not engineers. They from an Amish-like ecosphere. The colony ship went off-course. Their pod and many others forgot they were on a ship. The main character learned the secret and was ostracized from the pod by the elders. The colony ship going to crash into a star in a few Earth standard years unless they could get to a place called "The Bridge".
It came out in late 1973, which has often led me to wonder about the similarities between it Metamorphosis Alpha which came out 1974.
Harlan Ellison was involved in it, and like his rep, got pissed off and disavowed it. Kier Dullea (of 2001: A Space Oddyssey) was the star.

Ben Bova wrote a satirical take on the scifi TV/movie biz and fictionalizing Harlan's various run-ins with the industry.

http://greatbutforgotten.blogspot.com/2008/05/starcrossed-book.html

The killer part for me is the ending when Bova is predicting effectively CGI effects and modelling eliminating actors, producers, executives and directors, reducing costs and letting writers tell the stories they want without distraction so avoiding all the pain. The reaction that gets is priceless.

 

[Ulsyus]

There was also the Ringworld RPG based off of Larry Niven's Known Space books and

That was a neat little game. I think there was only the original box set and Companion, but the setting of the Ring was massive enough to put any setting into it. As long as the players didn't have advanced (TL9+) vehicles, there'd be plenty of Travelling to do on something like that.

 

[aramis]

Yeah, I think those were mentioned in the thread. I think it largely depends on the tech level. A 1960s civilization (tech 5 or tech 6) might have issues with structural integrity. But it would be interesting for players to visit a kind of vaccuum tube or transistors you can hold in your fingers kind of civilization. It would be an odd mix, but interesting.

I guess the practical issues, to me, get pushed aside when considering them for a game environment. My real issue it with heat build up, and in the case of a ring world, water and atmospheric spill off. What happens when you get to the edge or the "entry port" of a sphere or ring?

I don't know. I think it's still worth exploring for a home-brew gaming session.

Physics says you can't do a proper shell - the math shows that the needed strength of the material is greater than the strength of any known chemical bond - for a Dyson Shell. Simply put, even monomolecular cannot hold such a shell at a useful distance from even a small star.

You can do a series of rings at different inclinations - but rings are pretty unstable. (See Niven's author's notes for Ringworld Engineers).

You can use active suspension systems (orbital loops holding a surface in place via magnetic means) - but why would you? It's 10x the material for the same surface area, and higher risk of failure, as well as much more damage when it does fail.

Ringworlds barely make sense. Shells don't make sense.

 

[Blue Ghost]

Well, it is fiction. I think the only time you want to worry about the "reality" of a thing is how it'll impact the rules (which is why I brought up heat) and consequently the players. I've never been a fan of them as such, but I do think they're interesting.

Even so, I'm not inclined to agree that an advanced civilization, or one with a lot of resources, would be inclined to build one of these things. It just seems like even if you could overcome the engineering, that there wouldn't be enough social patience for any species to embark on such a project, unless they had achieved something like immortality and mastery of super dense alloys.

But, if they had, then it's interesting to think about what exploring one would be like.

I'm still wondering what happens when you reach the edge of a ring world. Is there a massive barrier there? I'm assuming there would be. Does it reach up and arch around for several miles to create the ringworld's "sky"? It would probably have to. If that's so, then how do you get in?

I think spinning either a ring or shell would be a matter of preference. For a ring I guess it's a given because that's how you generate gravity. But, as per your counter, would it fail? As you say, it would depend on the thickness of the thing to keep it from failing.

A high tech civ wouldn't be bothered because of gravitics. A lower tech civ might be taking its chances.

 

[Barrel]

" My real issue it with heat build up, and in the case of a ring world, water and atmospheric spill off. What happens when you get to the edge or the "entry port" of a sphere or ring?"

Well, in Niven's ringworld he put walls a thousand miles high at the edges.

In a Dyson "shell" (as opposed to the "swarm" which Dyson hypothesized) for an entry/exit port you could just have a tube a thousand miles high, or however high it would need to be to be to keep the atmosphere from spilling over. It would lead from the outside to the inside of the sphere; ships would just fly though it to the interior, then go over the tube's edge and descend into the atmosphere for landing.

 

[tjoneslo]

In a Dyson "shell" (as opposed to the "swarm" which Dyson hypothesized) for an entry/exit port you could just have a tube a thousand miles high, or however high it would need to be to be to keep the atmosphere from spilling over. It would lead from the outside to the inside of the sphere; ships would just fly though it to the interior, then go over the tube's edge and descend into the atmosphere for landing.

The challenge with the Dyson shell with no gravitics is there is no gravity on the interior. Well, not quite true. There is a slight gravitational pull toward the central star. So one design I've seen has two spheres. The outer solid one and an inner transparent one. Everyone lives on the surface of the inner sphere and the outer sphere is used for agriculture.

Depending upon the atmosphere pressure between the two shells, you will either need an airlock on the outer shell, or the tube goes into the inner space. These airlock tubes may also be part of the support system that keeps the two spheres to crashing into each other.

 

[Blue Ghost]

Yeah, if it's a shell, then what happens when you start to head to one of the poles. It would make for an interesting trek.

 

[aramis]

Yeah, if it's a shell, then what happens when you start to head to one of the poles. It would make for an interesting trek.

Assuming a spin grav....

Gravity transitions from outward vertical to inward vertical, deflecting towards the equator, as rotational speed decreases as you approach the poles.

This also means that the pressure of atmosphere, unless constrained, drops as one approaches the poles.

Further, the water cycle results in most water flowing towards the equator for the same reason.

Now, with sufficiently high barriers at various points, one can get multiple bands of isolated atmosphere (300 km tall should be sufficient for the internal baffles).

You also want similar longitudinal baffles to maintain atmospheric spin speed. If you don't, then only friction maintains the airspeed, and you get horizontal storm cells at various obstructions. (Niven discusses this effect in RWE.)

Given that you functionally need the baffles, you can literally make world sized baffle sections which are airlock joined.

 

[Barrel]

Niven also wrote that if you don't want to let any sunlight/energy go to waste, the sides of his ringworld could be "roofed over", creating a film canister shape. Then you still capture all the star's energy, but don't have problems with the water and atmosphere running "down" to the equator.

Of course, as has been pointed out, the tensile strength needed is greater than any material could possess. Ringworlds and Dyson shells really only work with artificial gravity--unless you want to say "The Ancients made it!"

 

[tjoneslo]

A discussion, with pictures and examples of a Dyson Swarm. Unfortunately the examples are all java applets, which don't run in today's browsers. The description of how you need to keep the swarm stable over a long period of time is an interesting addition.