3 ms·

Will we ever build ringworlds?

17 points by tommoor 11y ago

ccvannorman 11y ago
>"They are a solution in search of a problem." The problem is that Earth won't last forever, and terraforming is limited to existing terrain. >"[Paraphrased] Making a ring world around a star would be colossal and it would spin at 12,000 MPH!" Why build it around a star? A ringworld a few miles in diameter orbiting a star as the Earth does would be sufficient.
- mcv 11y ago
  I don't think it's fair to include wheel-shaped space habitats (like the one from Elysium) with Niven-style ringworlds. The physics involved is totally different on every possible level, and they are actually buildable.
erikb 11y ago
Uh, probably like most other people here I have to disagree. It's quite likely that rings in one form or another will succeed. They are a simple and efficient design. From space stations to rings around planets to rings around stars there are many levels possible. And some of the assumptions loook clearly wrong to me. Like the amount of energy to increase the speed of an object of that size is certainly huge, but it's much easier in space than on earth. On earth the faster you want to go the more energy you ned for every additional kmh, but in space you don't have all that annoying atmosphere to wiggle through. So you really just need a constant amount of energy until you've reached your target speed and then you just need to correct the speed and direction here and there. The reasoning about the vast amount of ressources needed is correct but not that much a problem, imho. No matter what you do. If you want to put millions of people into space you need to invest a lot. But we certainly reach that capability one day. Last but not least, one thing were a ring is much much better than a terraformed planet: Let's say we want to travel to another galaxy. Then having a ring it's much easier to travel there than trying to move a planet out of its orbit.
- jadell 11y ago
  If you have the technology and resources to move a ring of that size, then you also have the technology and resources to move a planet. Ringworlds are many orders of magnitude more massive than a single planet.
mcv 11y ago
>"They are a solution in search of a problem." No, they are not a solution, because they cannot work. Also, I object to the article including the (immensely cool) Elysium space habitat as a ringworld. It's not orbiting a star, and is completely unrelated to Niven's Ringworld or any kind of Dyson sphere, apart from the fact that it's in space and people live on it. It's a luxury space habitat, and something that we actually may be able to build some day, unlike true ringworlds.
rbanffy 11y ago
Well... Using a ring around a star to collect energy is much easier than a ring that produces gravity by rotating at speeds much higher than escape velocity. For one, it doesn't even need to be a rigid single structure but could be a fleet of smaller machines simply orbiting the star. Another worthy point is that rings and cylinders have a much better surface to mass ratio than planets, so, with that mass of even a small planet one could maintain a human population of many trillions.
- sliken 11y ago
  Heh, much higher than escape velocity is quite an understatment. I believe the velocity required is a decent fraction of the speed of light.
InclinedPlane 11y ago
Rather unlikely. They would require enormous amounts of raw materials, would need to be constructed out of things that are so far beyond the state of the art they might as well be magic, and would be dynamically unstable besides. Much smaller ring-shaped stations such as Banks' "Orbitals", quite likely, up to the limits of material science. But I'd be surprised if any true ringworlds existed in the entire Universe, or ever will.
Shivetya 11y ago
Let us be honest. If we could why would we need too? Really, if we had the technology and ability would not our tech out strip the problems having a ringworld supposedly corrects?
shalmanese 11y ago
Is there even enough matter in the solar system to build a ringworld? Once you start importing matter from other solar systems, the costs go up immensely.

17 points by tommoor 11y ago

>"They are a solution in search of a problem." The problem is that Earth won't last forever, and terraforming is limited to existing terrain. >"[Paraphrased] Making a ring world around a star would be colossal and it would spin at 12,000 MPH!" Why build it around a star? A ringworld a few miles in diameter orbiting a star as the Earth does would be sufficient.

mcv 11y ago
I don't think it's fair to include wheel-shaped space habitats (like the one from Elysium) with Niven-style ringworlds. The physics involved is totally different on every possible level, and they are actually buildable.

erikb 11y ago

Uh, probably like most other people here I have to disagree. It's quite likely that rings in one form or another will succeed. They are a simple and efficient design. From space stations to rings around planets to rings around stars there are many levels possible. And some of the assumptions loook clearly wrong to me. Like the amount of energy to increase the speed of an object of that size is certainly huge, but it's much easier in space than on earth. On earth the faster you want to go the more energy you ned for every additional kmh, but in space you don't have all that annoying atmosphere to wiggle through. So you really just need a constant amount of energy until you've reached your target speed and then you just need to correct the speed and direction here and there. The reasoning about the vast amount of ressources needed is correct but not that much a problem, imho. No matter what you do. If you want to put millions of people into space you need to invest a lot. But we certainly reach that capability one day. Last but not least, one thing were a ring is much much better than a terraformed planet: Let's say we want to travel to another galaxy. Then having a ring it's much easier to travel there than trying to move a planet out of its orbit.

jadell 11y ago
If you have the technology and resources to move a ring of that size, then you also have the technology and resources to move a planet. Ringworlds are many orders of magnitude more massive than a single planet.

mcv 11y ago

>"They are a solution in search of a problem." No, they are not a solution, because they cannot work. Also, I object to the article including the (immensely cool) Elysium space habitat as a ringworld. It's not orbiting a star, and is completely unrelated to Niven's Ringworld or any kind of Dyson sphere, apart from the fact that it's in space and people live on it. It's a luxury space habitat, and something that we actually may be able to build some day, unlike true ringworlds.

rbanffy 11y ago

Well... Using a ring around a star to collect energy is much easier than a ring that produces gravity by rotating at speeds much higher than escape velocity. For one, it doesn't even need to be a rigid single structure but could be a fleet of smaller machines simply orbiting the star. Another worthy point is that rings and cylinders have a much better surface to mass ratio than planets, so, with that mass of even a small planet one could maintain a human population of many trillions.

sliken 11y ago
Heh, much higher than escape velocity is quite an understatment. I believe the velocity required is a decent fraction of the speed of light.

InclinedPlane 11y ago

Rather unlikely. They would require enormous amounts of raw materials, would need to be constructed out of things that are so far beyond the state of the art they might as well be magic, and would be dynamically unstable besides. Much smaller ring-shaped stations such as Banks' "Orbitals", quite likely, up to the limits of material science. But I'd be surprised if any true ringworlds existed in the entire Universe, or ever will.

Shivetya 11y ago

Let us be honest. If we could why would we need too? Really, if we had the technology and ability would not our tech out strip the problems having a ringworld supposedly corrects?

shalmanese 11y ago

Is there even enough matter in the solar system to build a ringworld? Once you start importing matter from other solar systems, the costs go up immensely.