"Real" ringworlds

[Aloofi]

Maybe an sphere world should be as big as a Red Giant, but then of course it would overlap the other planets.....
One question, when an sphere world is build, isn't it suppose to block the sunlight completely, thus making all the other planets in the solar system too cold to be habitable without domes?

[Primogenitor]

A bit of background on ringworlds etc.

Niven did write 3 very good books based on a ringworld, including all the physics required etc. Also spawned an RPG and several other books.

It basicly works out that the RW needs to be made of a material as strong as an atomic nucleus (imposisble). To generate gravity its spun at 770 million miles per second around the sun. To do this requires as much energy as our sun produces in several billion years and is therefore impossible. Day/night is generated by panels (Shadow squares) on an inner orbit. Both these panels and the ringworld are not in stable orbits; i.e. if an asteroid hits either panels or RW they would eventually drift and crash into the sun, or each other. This also happens if there is a gravity disturbance, by another planet for example. Corrected by giant thrusters of some sort. Atmosphere is held in by walls 1600 km high at the endge, however if anything punctures the bottom, all the air is forced out and the resuting thrust crashes it into the star. Again.
It has a mass that is only about 350 times that of earth, it is about a million miles wide and about 600 mllion miles long, all habitable. Thats about 3 million earths! Big, very big.

[Desdinova]

if you can put one more impossible in there we can all go have breakfast at Milliways.

[narf poit chez BOOM]

we couldn't do it, but someone with 90 million years of research probably could. if you could find some way of lowering inertia....

[Primogenitor]

The problem is, if you can build one of these, why do you need it? You would probably have mastered mass-energy convserion, intergalactic travel, and many other things. So why go through all the effort? Yes one of these has the area of 3 million planets, but thats only a fraction of all the planets in the galaxy.

[Primogenitor]

sphereworlds: a how-to guide

A typical sphereworld is a solid shell, however without anti-grav everything falls into the sun. If you spin it then all the atmosphere moves to the equator and it bulges. You could cover the inside with solar cells and inhabit the outside.

Another aproach is to use a large network of orbiting platforms, like satalites. They dont have gravity and you would need a lot to completly block the sun complelely however. Also if one crashed then you would get a chain reaction.

My personal favourite would be to build a set of ringworlds, all at diffferent angles within each other.

[Primogenitor]

In a game context, the size of a ringworld would vary depending on species and/or sun. A cold species would want a larger ring/cooler sun etc. Ideally you would only have the ringworld and one sun in a system, plus warp points. However, the ringworld should have no mineral content. After all you only have what you put there in the first place!

Ive experimented with pre-generated ringworlds in a system. Its not too bad but either they have to be gas/none (they apear in other places otherwise) or you have to re-write all the systems that have planets of any/any/any type to be more specific. I cant find any appropriate pictures though, Ive resorted to copying the star background and drawing a circle on it with paint!

[Gwaihir]

One reason to build one is to have 3 million very high quality, custom-built planets, all conveniently located in the same solar system, so that you can do whatever you want to do on a massive scale without needing to waste time and energy shuttling stuff back and forth between 2 million star systems. Also, you can do as Niven's Ringworld engineers did, and build in a bunch of ecosystems, installing all sorts of living things in a huge zoo, where each exhibit is a whole planet in size, with plenty of geography to explore.

Plus, if you can, why not? Having mastered the universe, sounds like a fun project to keep you busy for a while. You're already able to play god on a little scale, creating custom living organisms and such, so why not go all out and make a custom planet, only make it bigger and better than the planets! Be good practice if you want to start building netowrks of stars, too - start small

or better yet, neworks of black holes - i bet you could get a lot of energy (or *something*) out of an orchestrated system of black holes, somehow.

[Primogenitor]

I havnt read the culture novels so im not too sure about this but here goes. I got some background from the site below, by banks himself (apparently)
culture orbitals and stuff

A bit of basic research shows that it would have to be as strong as a ringworld. I like the idea of building it from pairs of plates and cables(sound familiar?), you could apply that to ringworlds too, to a degree. An orbital would be useable if unfinished, you would just have to have temporary walls around the edge. Ringworlds could be built from orbiting plates, but couldnt be spun at full speed untill completed.

Each orbital holds 20 earths surface and 1 earth can be made into 1500 orbitals. By contrast a ringworld is made from 250 earths and has 3 million times the surface area. So by orbitals 1 earth => 30000 earths and by ringworld 1 earth => 12000 earths. So orbitals are more efficient (in terms of surface area/mass ratio) and easier to make (cos smaller).

I have found one reaseon for contruction, going back to the original dyson sphere. Since all known energy is derived from the sun (eventually) to achieve maximum efficency you would have to cover all the sun with solar panels to harness it to maximum capacity. This is a sphereworld (without being lived on). It wouldnt have to be very large, only to about the orbit of mercury at most. Surely it would be easier to start a small star separatly though? cold fusion, for example

[Primogenitor]

Every single living organism on this planet .... wants to do only one thing: Find and fix problems.

Thats not stricly true. There is no concious disire to "fix problems". Its simply that those that do not "fix problems" die. Conside a group of foxes and a group of rabits. The foxes chase the rabits, the slow rabits are caught and die, so the remaining rabits are the only ones that can breed and the next generateion are on average faster. The slow foxes don't catch any rabits and die of starvation. Therefore only the fastest foxes breed and the next generatin is also, on average, faster than the previous one. This kills the slower of the new rabits, which get faster, and then starve the slower foxes, which get faster,..... and so on ad infinitum. Until you get light speed rabitts

We have ears because long ago things with ears did better than things without ears. Then things with relatively good ears did better than things with relatively bad ears. etc

Its a great debate whether this applies to emivromentaly mannipulative organisms (humans) because there nothing to compare us with. As a species, nothing hunts us, we dont have to struggle for food, we change our eviroment to suit us rahter than us changing to suit our enviroment, virtually everyone has children.

The question is, given everything else is equal, will a group that builds a ringworld do better than a group that doesn't build a ringworld. But how do you measure better?