Traveller Ringworld

[TKalbfus]

Objection 1' (1 Prime): making cables, even out of steel, to the size and specifications required would be an engineering feat bordering on magical. At the very least, you'd need orbital production facilities and the ability to move really big pieces of steel over very long distances.

This is a matter of resources not technology. Ringworld technology is still more advanced than what we have today. What is needed mostly is machines to do the building, machines building machines out of a collapsing gas cloud that is forming a proto-star system.

Objection 2': what you propose is more complicated mechanically than the Niven design, hence more likely to fail over the geologic lifetime of an artifact such as the ringworld. You have set the system up in such a way that you guarantee eventual catastrophic failure, unless you commit to a maintenance program on a massive scale, spanning tens of thousands (or maybe even millions) of years. It will also require a lot more material, most of it heavy elements which are more scarce. Though he doesn't come out and say this, Niven implies that the Pak were able to manipulate substances at the atomic level, which means you could even tease scrith out of lighter, more common elements such as H or He.

Machines that are smart enough to build more copies of themselves are also smart enough to repair and maintain the ringworld over a geologic period of time whether the Ancients are still around or not.

Objection 3': The Niven design, once built, needs only energy input from the star it encircles. The star provides light and heat to drive the ringworld's ecological carbon cycle. The star also provides fuel, in the form of cast off hydrogen "wind" for the ringworld's Brussard station-keeping jets. Being a much simpler design overall, there's less to go wrong, hence fewer opportunities for catastrophic failure over the geologic lifetime of the artifact.

Nivens design is simpler and easier to explain as well, it just requires that magic substance that we don't have. What I just suggested is an engineering trick to get around not having that subtance, makes it more complicated, but thats the price you pay for lowering the tech of a ringworld.

Once "spun up", Niven's ringworld maintains a constant velocity because nothing is left in the system, besides the star, to slow it down. (Niven didn't deal with interstellar dust clouds, etc. and their effect on an object as massive as the ringworld would probably be negligable). That's why he makes a point of stating that the ringworld system was empty except for the structure and its star. You either need to start with a star that never developed a planetary accretion disk or one in which the builders removed everything else. So all that the ringworld needs is light and heat for its ecosystem and a minimal amount of "fuel" for station keeping.

The ringworld is made out of the dust cloud using up all the material to make planets and some of the material to make the star itself before it is completely formed. Stars comprise alot of matter, if you can catch that matter before it becomes part of the star you can have enough material to build a ringworld while dumping the excess back into the star so no planets form.

Your ropeworld will need constant input of energy sufficient to create the maglev effect between the rope structure and the ringworld, proper. Do you get that from the star? If so, how? And how do you spin the maglev track up to speed? Oh yeah, how do you make cables that massive out of tungsten? Isn't it one of the more difficult metals to work with?

Well stars provide a constant output of energy over their multi-billion year lifetimes. Okay the Tungsten cable is assembled on orbit (zero-G) around the protostar using tungsten extracted from the gas cloud as it collapses into the star. Most of that tungsten would have ended up in the star anyway while little bits of it would have become parts of planets and asteroids. You can aquire as much tungstein as you need if you choose your collapsing gas clouds carefully, then you allow enough infalling matter to accumulate to form a G-Class star while your building the ringworld. The cable and the ringworld are both initially in orbit around the protostar. The cable is much more massive than the rest of the ringworld. So you use solar power augmented by fusion reactors to generate electricity, driving the maglev motors that push on the tungsten cables. This slow the tungsten cables down while speeding up the rest of the ringworld to produce 1-G on its inner surface. The cables slow down from their initial orbit velocity to become stationary. The rest of the ringworld pushes the cables outward, the star's gravity pulls the non-rotating cable inward, and the cables tensile strength takes care of the rest.

Objection 4': You've envisioned your ropeworld as a structure which is pulled rigid by gravity, but that assumes the ropeworld would be stationary in space!

See above. Using Newton's laws of motion, the light ringworld pushes on the heavy cable using solar electic energy to drive the maglev motors. If the masses are proportioned right the cable will come to a complete stop while the ringworld will end up spinning at the right velocity. The centripetal momentum on the ring world will hold the rope away from the sun, while the "rope prevents the ringworld from breaking apart.

Niven's ringworld spins faster than orbital velocity, which counteracts the star's gravitational pull. That's why in Ringworld Engineers Niven had to explain the presence (or lack thereof) of attitude jets along the rimwall. Your design doesn't address this problem and your "ring" of cables would eventually drift off-center until it contacted the star.

I haven't mentioned altitude jets, but I assume their presence and they would word fine in this version of the ringworld just as they did with Niven's Ringworld.

You've proposed a design which assumes all of the complexity of desigining and building a massive, unstable structure, but none of the simplicity which would be required to allow this structure to survive for a long period of time. Niven's idea is better than yours because, magic tech aside, it's simpler and less prone to catastrophic failure.

Most structures not found in nature are not stable, that's why you need technology to stabilize it. Niven's ringworld may have been abandoned, but its technology was still functioning well enough to keep ints position stable. That's what I'm assuming here as well. Niven's ringworld is only slightly simpler than mine. There is alot of hidden complexity on both systems that you don't see, and in both cases they are taken care of by artifact technology that maintains itself to some degree.

 

[savage]

Interesting topic. Its been a while since I read Nivens' ringworld.

Whomever builds this monster would want it to last for a long time. Simple is good. But it would be better with a thick crust so that the builders would not have to import everything that went into the ring world's surface communities. First rule of thumb might be don't mine the outermountains for materials because theirs nothing useful anyhow.

Secondly regarding fossile fuels...up until a certain time our ancestors used whale oil. So, perhaps a similar functionality could come from the animal life of Ringworld. The oceans would be enormous in scale and could maintain significant plant and animal life. Some of these might have useful bi-products that allow tech to flurish. Also their might be the possibility of 2300 style biotechnologies. I see no reason for a limited technology. Ringworld would have to be able to withstand sentient forces and mistakes as well.

Just a few thoughts.

Savage

 

[EvilDrGanymede]

The ringworld is made out of the dust cloud using up all the material to make planets and some of the material to make the star itself before it is completely formed. Stars comprise alot of matter, if you can catch that matter before it becomes part of the star you can have enough material to build a ringworld while dumping the excess back into the star so no planets form.

Um, hello? Did you even read the post I made earlier about how nonsensical and completely impossible this is? It'd be foolish beyond measure to attempt to build anything artificial out of a protostellar cloud. A ringworld is enough of an engineering challenge without having to worry about gas drag, superflares, hyper-strength solar winds, and planetesimal impacts...

 

[roygbiv]

Originally posted by Savage:
Interesting topic. Its been a while since I read Nivens' ringworld.

Whomever builds this monster would want it to last for a long time. Simple is good. But it would be better with a thick crust so that the builders would not have to import everything that went into the ring world's surface communities. First rule of thumb might be don't mine the outermountains for materials because theirs nothing useful anyhow.

You can't mine scrith. The idea was that the Pak would be keeping an eye on things. Therefore the only "tech" available was what was left over after the Puppeteers engineered a collapse by seeding the Ringworld with bacteria which ate superconductor. Before that, homonid civilizations probably used matter transformation technology similar to that used to produce the scrith.

Secondly regarding fossile fuels...up until a certain 0time our ancestors used whale oil. So, perhaps a similar functionality could come from the animal life of Ringworld.

In The Ringworld Engineers, the Machine People use methane. Though, presumably, this option could be available.

The oceans would be enormous in scale and could maintain significant plant and animal life. Some of these might have useful bi-products that allow tech to flurish. Also their might be the possibility of 2300 style biotechnologies. I see no reason for a limited technology. Ringworld would have to be able to withstand sentient forces and mistakes as well.

Niven's novels actually postulate more of a TNE-style setting. It's post-collapse and there's all this ultratech lying around, mostly useless. Still some groups are able to utilize a few caches to form TEDs. And then there's the "escape project" which is looting the rim of attitude jets in order to flee the Ringworld.

 

[savage]

Roygbiv,
Thanks for refreshing my memory.

When I was discussing mining I was referring to non-scrith metals; iron ore, silver, copper not too mention sulfer and common elements.

Perhaps basing some of the science on Niven is a wise move but the science fiction has many alternatives.

If the our hull of the ringworld is a million km span of scrith then the materials between it and the living surface could be standard planetary materials. Afterall, your breaking up planets to create raw material for ring. And I tend to believe that grass wouldn't grow in scrith either.

Making a ringworld liveable is almost as important as the basic structure. If you want to throw up a 1,000,000 new buildings throughout the world would you really want to ship in more material. After time it would modify the mass depending on the original plan. And depending on the world do you really want 10s of billions using matter converters on a daily basis. The more world like the better.
I'll have to pull out the book and re-read the descriptions one day. Either way science should be able to progress on ring world if biotechnology is an available path and if the world is fundementally earth-like.

Are Niven's attitude jets really necessary. If you could build such a thing wouldn't its mass keep itself straight versus the star. If not a chain of rim based volcano's could have a similar effect. Assuming the jets used some sort of fuel. The weather challenges would also be enormous. Five Thousand mile long hurricanes...etc. I heard on weather channel that we have 1800 lightning storms per day world wide....think of ringworld.
I am assuming that you'd want a functional atmosphere with ozone, weather, and breathable gaseous mixes.

Savage

 

[ninthcouncil]

Originally posted by Savage:
Are Niven's attitude jets really necessary. If you could build such a thing wouldn't its mass keep itself straight versus the star

The problem is that, because the Ringworld is a symmetrical structure about the central star, all the gravitational forces cancel out. So whereas a lone planet orbits, the Ringworld just drifts. Once it drifts away from symmetry, the bits closer to the star are pulled more than the bits further away, with cumulative effects. It's unstable, like a coin balanced on its edge - any disturbance and plonk, over it goes. The attitude jets are required to keep the thing on station in order to prevent this.

 

[TKalbfus]

Um, hello? Did you even read the post I made earlier about how nonsensical and completely impossible this is? It'd be foolish beyond measure to attempt to build anything artificial out of a protostellar cloud. A ringworld is enough of an engineering challenge without having to worry about gas drag, superflares, hyper-strength solar winds, and planetesimal impacts...

The ringworld and the star are basically the same age. The ringworld is made out of all that stuff you mentioned and the rest is dumped into the star, so their is basically nothing to collide with the ringworld when its finished. The ringworld is not spun up until the star system is cleaned up. The ringworld also has a meteor defense system that's good for something other than shooting down starships. The ringworld has an inner ring of shadow squares that regulate the light that reaches the ringworld and can protect from solar flares. The ringworld has a donut shaped magnetic field, so flares are generally confined along the north-south access.

 

[TKalbfus]

You can't mine scrith. The idea was that the Pak would be keeping an eye on things. Therefore the only "tech" available was what was left over after the Puppeteers engineered a collapse by seeding the Ringworld with bacteria which ate superconductor. Before that, homonid civilizations probably used matter transformation technology similar to that used to produce the scrith.

This is not Larry Niven's ringworld, see my previous posts, My design for the ringworld does not require scrith, but you don't have to tell the players that, they may come to the ringworld seeking the superscience material as a sort of El Dorado. What is required is a balance of forces to hold the ringworld into a ring. Larry Niven assumed a super strength material to counteract the centripedal tendency of the ringworld to fly apart. I instead use ordinary material, more of them than Larry Niven, and magnetic levitation to hold the ringworld in place. The ringworld I mention is analogous to the Great Pyramids of Egypt. Other nations of that time had the technology to build pyramids as well, but not all of them had the resources or the werewithal to build them. This ringworld I propose is a Traveller setting, it is roughly the same size as Niven's ringworld but it is not Niven's ringworld. You won't find Puppeteers or Kzin here.

The ringworld would also have taken a long time to build. Most organic species would not have the patience to build it and in the Traveller Universe technological innovation would have made it obsolete before it was completed. However it might have been built by a civilization of pre-Ancients that were not innovative and governed by a computer that was primarily concerned with stability. The Computer would have kept the Pre-Ancients at TL8 for countless millenia until they finally rebelled, escaped the ringworld to become the Ancients. All but forgotten, the computer maintained the ringworld and sent out its interstellar ramjets to look of other intelligent species to "serve", and thus fulfill its programming. The computer with all its subprograms have, over the past few million years, collected a number of intelligent species from the OTU, and have placed them on the ringworld. When the PCs discover the ringworld, this AI is "asleep" and only its automatic systems are functioning. The AI computer wakes up every few hundred years to check up on the ringworld and then shuts down its higher processes when its satisfied that conditions are nominal.

 

[roygbiv]

Originally posted by Tom Kalbfus:
This is not Larry Niven's ringworld, see my previous posts

Yes it is, Tom. See Savage's previous posts.

There's more than one conversation going on here. Savage and I are discussing Niven's design. I don't know about Savage but I consider it a more likely candidate for the OTU ringworld, You're talking about your idea for a ringworld, which IMO requires more material, most of it relatively rare, and at least as high a level of technological accomplishment for exactly zero improvement over Niven's design.

Your ropeworld is only distantly related to the ringworld alluded to by canon materials. Understand that when you go out on that limb, not everyone is interested in following you.

 

[rancke]

Originally posted by Tom Kalbfus:
Thicker cables have more tensile strength. If you make the cables thick enough they will be strong enough to hold the ringworld floor in a circular orbit around the sun.

No. There's an upper limit to tensile strength. It is reached when the weight of the cable is enough to break it.


Hans

 

[TKalbfus]

Yes it is, Tom. See Savage's previous posts.

There's more than one conversation going on here. Savage and I are discussing Niven's design. I don't know about Savage but I consider it a more likely candidate for the OTU ringworld, You're talking about your idea for a ringworld, which IMO requires more material, most of it relatively rare, and at least as high a level of technological accomplishment for exactly zero improvement over Niven's design.

Your ropeworld is only distantly related to the ringworld alluded to by canon materials. Understand that when you go out on that limb, not everyone is interested in following you.

The Niven design requires a fictional material, my design is an improvement because it doesn't require this fictional material and may actually be possible in this Universe. The Rope world as you call it requires more material, but this material is in the form of known atoms, whereas there may be no substance in the universe that would have all the properites of this scrith. the requirement for Scrith is the weakness in the Niven Design, mine is merely hard to build with known materials. Anyway if we were to use Niven's Ringworld, we'd need Larry Niven's permision. An original Ring world would be better I think for the OTU.

 

[TKalbfus]

No. There's an upper limit to tensile strength. It is reached when the weight of the cable is enough to break it.


Hans

But the cable doesn't weigh anything in space, only the ringworld does due to its inertial resistance to being spun around the star. The cable does not spin with the ringworld so it weighs nothing.

 

[savage]

Wow this is a great discussion. Plenty of thinking going on. Didn't occur to me that a ring would behave in such a fashion orbiting a stellar gravity. Is there a way to modify a ring so it corrects its own course naturally? It would be interesting to read a physics white paper or thesis on the topic. Has any one ever seen one?

Yes I am discussing Niven's Ringworld and where its safe to move away from Niven's design. We should also be concerned with where (and if) his Logic is flawed based on today's science.

I do think that Niven's biological life forms are not necessarily significant to the ringworld discussion. Unless someone disagrees? My concern with what I've read over the 9 or so pages would be survivability. Computers to monitor it and correct its course...ok. But the more simple and planet-like ringworld is. The more survivable.

I also wouldn't eliminate the entire solar system. Several gas giants near jump points could provide economic value to lower tech commerce vessels. Any science capable of building it wouldn't be concerned with controlling large body movement within the system.
And would you destroy your homeworld or keep it nearby for the "yesteryear" park.
Who Built it in Traveller;
1. race that doesn't have star travel,
2. zenophobes or
3. a physically impared race to travel, or
4. by a race that want to achieve a great accomplishment. You know a Krell type of project.
There are plenty of reasons to build a ringworld. Your immediately the center of commerce for the known systems if you play your cards correctly.

I've also wondered about keeping it hidden. Do you need a pocket universe (I'm not a grandfather fan. Don't tell him, pls.)
1. How about the Star Wars method. "We've found a gravitic anomally near the empty quarter( or Corridor)... it doesn't appear in on the Imperium starmap."
2. Then again perhaps it appears to be a dangerous, thick asteroid belt from a distance. Sure what a great defense. The system is surrounded by an asteroid field with only a few navigatable paths. The ring uses tractor beams to push off any stray rocks not that it isn't tough enough to take rather large hits.

Also, if your building it. What better rock grinder than an asteroid field. The hard work would be a matter of trajectories. Then skim it to collect rubble.

Then there is the ring itself. If Niven's "nightime panels" were extended they could diminish the star in the night sky to any astronomers near..
a super alloy is fine by me. Its secret alone would only be worth the adventure. I'm still thinking about layout of the landscape. Planet sized oceans, small mountain ranges used to control and create weather patterns held in by two exterior mountain ranges. Heck the builders would've had contests to design the best shorelines (aka Hitchhikers Guide..).

One thing is for certain. It would need to be tough. Nuclear war wouldn't do more than damage sections of the surface. So, would/could you do continental plates shifting and moving between the permanent exterior mountains? What about heat. We get plenty of it from earth's core. Would the star be adequate or would the builders put their super allow on the bottom, then iron plates in molten rivers above which continental plates drift... anyone recall if Niven touched on this?

Savage

 

[rancke]

Originally posted by Tom Kalbfus:
</font><blockquote>quote:</font><hr /> No. There's an upper limit to tensile strength. It is reached when the weight of the cable is enough to break it.


Hans

But the cable doesn't weigh anything in space, only the ringworld does due to its inertial resistance to being spun around the star. The cable does not spin with the ringworld so it weighs nothing. </font>[/QUOTE]I give up. By that logic you could keep the ringworld together with sewing thread.


Hans

 

[EvilDrGanymede]

I give up too. Tom doesn't seem interested in listening to anyone who points out the glaring holes in his vision of a ringworld.

Of course, ringworlds are purely theoretical and require very advanced materials technology among other things, but the idea of building a ringworld in a still-forming system adds so many problems that it renders the task totally impossible and utterly futile, even with such 'magic supertech'.

 

[TKalbfus]

I give up. By that logic you could keep the ringworld together with sewing thread.

I keep trying to explain it to you. Perhaps an analogy would suffice.

The cable is a circular track around the star, and the ring world is the train that runs on that track around in circles.

The track is either in orbit around the star and so has no weight since it experiences zero- gravitational pull, or it is stationary with respect to the central star in which case the star's gravity pulls it inward, it makes little difference since the star's gravity is feeble at 1 AU distance any way. The track must hold itself in a circle while the ring world runs around in circles inside of it.

The track must bear the weight of the ring world but not of itself since it is in free fall around the star or in orbit, its own mass matters not. You can make the track as thick and as fat as you want so long as you have the material with which to build it. It doesn't have to be tungsten of course Iron or any other solid material will do. Its just that when something is dense, it doesn't have to be as fat.

Yes I am discussing Niven's Ringworld and where its safe to move away from Niven's design. We should also be concerned with where (and if) his Logic is flawed based on today's science.

Look at it this way, I am only presenting an option for you besides Niven's model. I'm showing you how to build a ring world without a magical super metal that is nearly indestructible. This is science fiction after all and you can imagine anything. If you are going to have your scrith just think for a moment what it would have to be made of. Atoms won't do, its not strong enough to hold together, perhaps some entirely new form of matter using some exotic particles instead of atoms, this is a lot of fantasy, I just happen to think that this superstuff is not necessary. Ordinary matter will do if you just change the way you build the ringworld, it really doesn't matter to the players as both ringworlds will look the same to them except they will be able to break a chunk off of my ringworld and analyse it to discover it to be made of Steel, carbon nanotubes or whatever, while the scrith will magically defy analysis, sort of a cop out on the referee's part in my opinion. But a ring world is a ring world, it doesn't matter to me, I'm only showing you how to make it better storywise and more scientific. You could make a ringworld out of an invisible "Wall of Force" as in the D&D spell and just pile dirt and rock on top.

I also wouldn't eliminate the entire solar system. Several gas giants near jump points could provide economic value to lower tech commerce vessels. Any science capable of building it wouldn't be concerned with controlling large body movement within the system.
And would you destroy your homeworld or keep it nearby for the "yesteryear" park.
Who Built it in Traveller;

Disassembling whole planets is hard to do, its much easier to mine dust clouds and asteroid belts. You also assume that just because a civilization doesn't have FTL, that it doesn't have an interstellar capability, that is not so. The ring world would take thousands of years to build, adding a century or so to travel to the construction site won't make much of a difference. Besides the populous will have to live somewhere while you ar disassembling their planet to build the ringworld, so you might as well locate it in a different solar system.

1. race that doesn't have star travel,
2. zenophobes or
3. a physically impared race to travel, or
4. by a race that want to achieve a great accomplishment. You know a Krell type of project.
There are plenty of reasons to build a ringworld. Your immediately the center of commerce for the known systems if you play your cards correctly.

How about a race that builds a machine that builds the ringworld? The machine builds other machines, which build yet others until there are enough machines to build the ring world. The race only has to concern itself with building that first machine just right and everything else follows from that. The race need not concern itself any further with the construction of the ringworld, the machines will see to that.
These machines are clanking replicators, not nanotechnology. In other words it is a system of factories and robots that collectively repair, maintain themselves, and build others of their kind and the ring world too. These machines need not be intelligent either, each one is specialized to do a certain task, but the whole network of all these machines is self reproducing and designed to build a ring world when enough copies of itself are made. The organic race might even have died out by the time the ringworld is complete. The machines according to their unthinking programming will gather organic life forms to put on the ring world to complete their programming, this may include humans. The machines don't care, they just do what they were designed to do.

I've also wondered about keeping it hidden. Do you need a pocket universe (I'm not a grandfather fan. Don't tell him, pls.)
1. How about the Star Wars method. "We've found a gravitic anomally near the empty quarter( or Corridor)... it doesn't appear in on the Imperium starmap."
2. Then again perhaps it appears to be a dangerous, thick asteroid belt from a distance. Sure what a great defense. The system is surrounded by an asteroid field with only a few navigatable paths. The ring uses tractor beams to push off any stray rocks not that it isn't tough enough to take rather large hits.

So long as you don't make it Super Duper Tech, you don't have to keep it hidden (ala X-Files). There are too many RPGs with "Men in Black" in it already. Just put the ring world in an unexplored part of space for the PCs to discover. Pocket universes are godlike super computers are just too much and unnecessary. I don't like ring worlds that just teleport in and teleport out with the PCs left to spend the rest of their lives in "straight jackets and rubber rooms" if they tell anyone about it, because no one will belive them. I'd rather have the political forces acknoledging the presence of the ringworld and let the referee determine how they react rather than use the UFO principle.

 

[roygbiv]

Originally posted by Tom Kalbfus:
The track is either in orbit around the star and so has no weight since it experiences zero- gravitational pull, or it is stationary with respect to the central star in which case the star's gravity pulls it inward, it makes little difference since the star's gravity is feeble at 1 AU distance any way.

Your track is neither "in orbit" nor is it "stationary with respect to the central star". There are no stationary objects in space.

Orbits are a balance between two centers of mass, in which one center of mass moves around the other center of mass. Your ropeworld's effective "center" overlaps the center of mass of the star. Don't believe me? Diagram it. Therefore any gravitational pull on the part of the star gets cancelled and the ropeworld cannot forever encircle the star. Our sun is moving through space. Its gravity is sufficient to pull the earth along with it, even as the earth circles the sun. That's a dynamic inherent in an orbit.

But your ropeworld isn't in orbit, so that dynamic doesn't exist.

The track must bear the weight of the ring world but not of itself since it is in free fall around the star or in orbit, its own mass matters not.

Its own mass always matters. You either have to spin it up or spin it down and you will always have to be applying some kind of thrust to this "stationary" ring to keep it centered on the star. It's not the supposed "weight" of the cables which will be important, rather their tensile strength versus angular momentum. Since you can't make up your mind as to whether the star's gravity attracts or is overcome by the ropeworld, weight isn't the limiting factor: angular momentum (which is probably much greater than the gravitational effect of its mass) is.

You can make the track as thick and as fat as you want so long as you have the material with which to build it.

You're picking and choosing your "superscience" here. Niven presupposed the capability to manipulate substances at the nuclear level in order to produce scrith. You're presupposing the ability to either transmute the raw materials of a planetary accretion disc, or to somehow magically manufacture "ropes" of extraordinary size, whose mechanical connections increase the number of points of failure, and then build another "inner" ring (I'll leave it up to you to deduce why an "outer" ring won't support an ecosystem). So how come Niven's approach is "fantastic" and yours isn't?

Have you done the math to determine exactly how much angular momentum these cables are going to have to resist? How do you know that this is less than what scrith will require?

It doesn't have to be tungsten of course Iron or any other solid material will do. Its just that when something is dense, it doesn't have to be as fat.

Sorry, I haven't seen any math yet. Your hands are waving too fast. Niven's design has been mathematically tested. What we cannot do is fathom how scrith gets created.

Look at it this way, I am only presenting an option for you besides Niven's model. I'm showing you how to build a ring world without a magical super metal that is nearly indestructible. This is science fiction after all and you can imagine anything. If you are going to have your scrith just think for a moment what it would have to be made of. Atoms won't do, its not strong enough to hold together, perhaps some entirely new form of matter using some exotic particles instead of atoms, this is a lot of fantasy, I just happen to think that this superstuff is not necessary.

You replace "superstuff" which makes you uncomfortable with "superstuff" that you are comfortable with.

I also wouldn't eliminate the entire solar system. Several gas giants near jump points could provide economic value to lower tech commerce vessels. Any science capable of building it wouldn't be concerned with controlling large body movement within the system.

They would have to be concerned with exactly that. Anything as large as a ringworld is going to wreak havoc on any existing orbits. Likewise, anything else besides a star is going to screw up ringworld station keeping.

I don't find your version credible and it's not supported by the OTU. We already disagree about adventure possibilities, maybe I should just agree to disagree about this as well.

 

[TKalbfus]

Its own mass always matters. You either have to spin it up or spin it down and you will always have to be applying some kind of thrust to this "stationary" ring to keep it centered on the star. It's not the supposed "weight" of the cables which will be important, rather their tensile strength versus angular momentum. Since you can't make up your mind as to whether the star's gravity attracts or is overcome by the ropeworld, weight isn't the limiting factor: angular momentum (which is probably much greater than the gravitational effect of its mass) is.

So, that's an engineering problem. A ring world is dynamically unstable, but so is a stealth bomber, without its active controls a stealth bomber would crash, its shape does not make for a very good dead stick glider. A ring world has a continous source of energy to work with, it should be able to apply thrust as needed to maintain its position.

You're picking and choosing your "superscience" here. Niven presupposed the capability to manipulate substances at the nuclear level in order to produce scrith.

There is no substance on the chemical periodic table that has the properties of scrith. You can make new elements that are not on this chart, but these elements would have a half life of one fraction of a second. There may be islands of stability, but even these elements would be highly radioactive and decay quite rapidly. The Universe has got to provide the material that Larry Niven needs, if it does not, there is little that science can do, it cannot locally change the laws of physics to allow for this impossible substance. Perhaps their are unknown laws of physics that would allow for the existance of such a substance, but those laws of physics would have to exist to build Niven's ring world, if they don't it cannot be invented. My proposal is to build the ring world out of material that exists in our universe, this requires some engineering and some balance of forces but I believe it to be possible while Niven's ring world may or may not be.

You're presupposing the ability to either transmute the raw materials of a planetary accretion disc, or to somehow magically manufacture "ropes" of extraordinary size, whose mechanical connections increase the number of points of failure, and then build another "inner" ring (I'll leave it up to you to deduce why an "outer" ring won't support an ecosystem). So how come Niven's approach is "fantastic" and yours isn't?

Niven's ring world requires it to exist in a certain universe with specific laws of physics that we don't know about. The stuff scrith is made out of is not normal matter, its not made out of atoms, but of some other type of particle. This particle has to be able to interact with normal matter, and yet have stronger interparticle forces than atoms do in order to have this super fantastic tensile strenght to mass ratio. The matter to make my ringworld already exists, most of the materials we need are inside our sun since that's where over 99% of all the matter in the Solar System is. Hydrogen is useless as a building material. We need to extract the iron, and carbon from the sun which can't be done easily, that is why you don't start with a finished solar system.

 

[TKalbfus]

Have you done the math to determine exactly how much angular momentum these cables are going to have to resist? How do you know that this is less than what scrith will require?

This loop of cable has no angular momentum since its not rotating. the only angular momentum is in the part of the ring world that is rotating. I can see that your pride won't allow you to conseed a single point, So you'll keep coming up with bogus objections. Angular momentum is simply the tendency of object that are rotating to keep on rotating. It works for science fiction and that's all that really matters. There seems to be a whole group of people on this board that are very resistant to new ideas, I don't know why that is, but you have failed to come up with a good idea that will knock down my proposal as a concept. We don't have to actually build a ring world, just to imagine one and to conceive how it could exists. All the engineering problems don't need to be solved, this is future tech after all. It would be a wasted exercise to try to solve all the engineering problems involved with the construction and maintenences of a ring world just to play a game. It only has to be believable to the players.

 

[EvilDrGanymede]

Originally posted by Tom Kalbfus:
</font><blockquote>quote:</font><hr /> Have you done the math to determine exactly how much angular momentum these cables are going to have to resist? How do you know that this is less than what scrith will require?

This loop of cable has no angular momentum since its not rotating. the only angular momentum is in the part of the ring world that is rotating. I can see that your pride won't allow you to conseed a single point, So you'll keep coming up with bogus objections. Angular momentum is simply the tendency of object that are rotating to keep on rotating. It works for science fiction and that's all that really matters. There seems to be a whole group of people on this board that are very resistant to new ideas, I don't know why that is, but you have failed to come up with a good idea that will knock down my proposal as a concept. We don't have to actually build a ring world, just to imagine one and to conceive how it could exists. All the engineering problems don't need to be solved, this is future tech after all. It would be a wasted exercise to try to solve all the engineering problems involved with the construction and maintenences of a ring world just to play a game. It only has to be believable to the players. </font>[/QUOTE]All the while here, the rest of us at least have been talking about a *realistic* ringworld. You on the other hand have been deliberately ignoring everyone else's valid physical objections to your ideas because they don't fit with your vision of a ringworld.

If you want a ringworld to be there in your game, put it there and brush over any questions your players may have by saying 'aaaah, it's Ancient magitech that nobody understands and it just works, so there' or some other such 'bogus explanation' of your own. You clearly have no concern for the physical realities of how a ringworld works anyway, and I doubt the rest of us care what you do in your own game.

But if you want to explain why it's there in a realistic universe, then you have to stick to the same laws of physics that everyone else applies to their universe - ones which you seem to think are 'bogus'. Sticking your fingers in your ears and saying 'LALALALA' is one thing, but saying that everyone else is WRONG to use valid physics to back up their arguments is just ridiculous.

This discussion is only meaningful if the universes that we're talking about have the same laws of physics. Your assumed universe clearly does not have the same laws as ours (actually, it seems to have a bizarre, inconsistent 'make it up as you go along' physics), therefore further discussion on this matter is a waste of everyone's time.

Science fiction is called that for a reason - because it has SCIENCE in it. You seem to be wanting just pure 'fantasy' here, which does not require any kind of scientific basis to work. The maths for the ringworld has already been provided by another poster here, and you have not provided any numerical evidence that your ideas are somehow superior to this. You've done nothing more than armwave and you expect us to take your word for it that you understand the physics of it better than anyone else, when from from what you've been saying it's clear that you have a very flawed understanding for the physics here.

Right now, you're dismissing else's valid physical objections because you refuse to see that your 'bogus' arguments are flawed. Until you admit this is the case, there's little point in continuing this discussion.