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I've heard this idea in the context of Dyson spheres/swarms. The issue is that, while they'd be invisible or dim to the eye, the areas would be very bright in i

by nynx 6y ago

I've heard this idea in the context of Dyson spheres/swarms. The issue is that, while they'd be invisible or dim to the eye, the areas would be very bright in infrared.

Retric 6y ago
Depends on how large the swarm is. Using our sun as the example a 1AU swarm would be very warm, but at 100 AU it would be extremely cold and much harder to detect. Really though, a Dyson’s swarm isn’t that efficient long term. It’s likely better to dismantle large stars and use fusion reactors with heat sinks at close to 2.73 Kelvin as possible.
- vermilingua 6y ago
  Fossil fuels vs solar, it’s a sustainability question. Plus, dismantling a sun isn’t much help to the planets orbiting it, and then you need to find a way to efficiently get that energy to another system to be used.
  - m4rtink 6y ago
    Planets ? Who cares about planets when building a Dyson swarm - other the possibly as a bootstrap cache of materials to get thing going. Yeah, you might occasionally leave one in place for historical reasons, but otherwise they are just too useless not to make use of their mass for something better. Not to mention traffic management headaches given that normal planets usually stubbornly refuse to do any orbit corrections when needed.
  - Retric 6y ago
    The amount of fuel is fixed either way so it’s an efficiency question. Normal stars only burn a small percentage of their fuel. Maximum energy is captured by turning hydrogen into lead. After that, dumping lead into a deep gravity well is the final option.
- Konohamaru 6y ago
  > Really though, a Dyson’s swarm isn’t that efficient long term. It’s likely better to dismantle large stars and use fusion reactors with heat sinks at close to 2.73 Kelvin as possible. Would like a referral to science fiction that talks about this.
  - m4rtink 6y ago
    Here you go: https://en.m.wikipedia.org/wiki/Stellar_engineering https://en.m.wikipedia.org/wiki/Stellar_engineering Also used in many places in Orions Arm: https://www.orionsarm.com/eg-article/47897e8b1947c https://www.orionsarm.com/eg-article/47897e8b1947c Whole star system optimized into a giant computing cluster with projected sun energy output for computing available for next 14 trillion years: https://orionsarm.com/eg-article/49125f5d1c049 https://orionsarm.com/eg-article/49125f5d1c049 (Or 100000 sun output for 140 milion years.) Himmelsschmiede - a full star system converted to useful heavy elements using a deep well industrial zone (basically an artificial black hole accreation disk): https://www.orionsarm.com/eg-article/46709da5de6be https://www.orionsarm.com/eg-article/46709da5de6be
mjevans 6y ago
At the very least we'd still be able to detect the mass within the region based on it's effects.
ncmncm 6y ago
The whole concept of Dyson Spheres, or anything even vaguely like that, is totally absurd. (Even Dyson said so.) Any space-faring culture will have mastered controlled fusion long ago, and have entirely left behind any material dependence on stars. The best places to live, then, are out in the Kuiper belts and beyond, where unlimited room and cold are available for free, and valuable gases are lying about, frozen. Inner planets are for extreme primitives. If aliens got here, they would find Triton much more interesting than Earth, except maybe as a curiosity. Expanding menace civilizations will run up against overwhelmingly more advanced stable cultures before long and be contained or destroyed, so odds are none could get here before that happens.
- m4rtink 6y ago
  Unless you can harvest interstellar medium at scale stars are where most mass is locked up, conveniently in a single place even. Outer belt objects are quite small in volume in comparison and inconveniently far from each other.
  - ncmncm 6y ago
    The outer belt objects are small compared to planets, but are enormous considered as extracted volume, and uncountably numerous; whereas on inner planets you are effectively limited to the solidified skin at the bottom of an annoying gravity well, bathed in heat that must be shed. Kuiper belt distances are inconvenient only when you are in a hurry and have limited speeds. Given fusion propulsion, nothing inside a solar system is especially far from anything else. But a large volume to operate in, which grows as r^3, is valuable, and an unlimited sink of cold, moreso. If you need more mass, Neptune is right there.
    - m4rtink 6y ago
      Good point - the exposed surface are for easy mining is pretty massive for outer system objects & accessible without the need for advanced stuff like planet cracking and solar lifting.

by nynx 6y ago

I've heard this idea in the context of Dyson spheres/swarms. The issue is that, while they'd be invisible or dim to the eye, the areas would be very bright in infrared.

Retric 6y ago

Depends on how large the swarm is. Using our sun as the example a 1AU swarm would be very warm, but at 100 AU it would be extremely cold and much harder to detect. Really though, a Dyson’s swarm isn’t that efficient long term. It’s likely better to dismantle large stars and use fusion reactors with heat sinks at close to 2.73 Kelvin as possible.

vermilingua 6y ago
Fossil fuels vs solar, it’s a sustainability question. Plus, dismantling a sun isn’t much help to the planets orbiting it, and then you need to find a way to efficiently get that energy to another system to be used.
- m4rtink 6y ago
  Planets ? Who cares about planets when building a Dyson swarm - other the possibly as a bootstrap cache of materials to get thing going. Yeah, you might occasionally leave one in place for historical reasons, but otherwise they are just too useless not to make use of their mass for something better. Not to mention traffic management headaches given that normal planets usually stubbornly refuse to do any orbit corrections when needed.
- Retric 6y ago
  The amount of fuel is fixed either way so it’s an efficiency question. Normal stars only burn a small percentage of their fuel. Maximum energy is captured by turning hydrogen into lead. After that, dumping lead into a deep gravity well is the final option.
Konohamaru 6y ago
> Really though, a Dyson’s swarm isn’t that efficient long term. It’s likely better to dismantle large stars and use fusion reactors with heat sinks at close to 2.73 Kelvin as possible. Would like a referral to science fiction that talks about this.
- m4rtink 6y ago
  Here you go: https://en.m.wikipedia.org/wiki/Stellar_engineering https://en.m.wikipedia.org/wiki/Stellar_engineering Also used in many places in Orions Arm: https://www.orionsarm.com/eg-article/47897e8b1947c https://www.orionsarm.com/eg-article/47897e8b1947c Whole star system optimized into a giant computing cluster with projected sun energy output for computing available for next 14 trillion years: https://orionsarm.com/eg-article/49125f5d1c049 https://orionsarm.com/eg-article/49125f5d1c049 (Or 100000 sun output for 140 milion years.) Himmelsschmiede - a full star system converted to useful heavy elements using a deep well industrial zone (basically an artificial black hole accreation disk): https://www.orionsarm.com/eg-article/46709da5de6be https://www.orionsarm.com/eg-article/46709da5de6be

mjevans 6y ago

At the very least we'd still be able to detect the mass within the region based on it's effects.

ncmncm 6y ago

The whole concept of Dyson Spheres, or anything even vaguely like that, is totally absurd. (Even Dyson said so.) Any space-faring culture will have mastered controlled fusion long ago, and have entirely left behind any material dependence on stars. The best places to live, then, are out in the Kuiper belts and beyond, where unlimited room and cold are available for free, and valuable gases are lying about, frozen. Inner planets are for extreme primitives. If aliens got here, they would find Triton much more interesting than Earth, except maybe as a curiosity. Expanding menace civilizations will run up against overwhelmingly more advanced stable cultures before long and be contained or destroyed, so odds are none could get here before that happens.

m4rtink 6y ago
Unless you can harvest interstellar medium at scale stars are where most mass is locked up, conveniently in a single place even. Outer belt objects are quite small in volume in comparison and inconveniently far from each other.
- ncmncm 6y ago
  The outer belt objects are small compared to planets, but are enormous considered as extracted volume, and uncountably numerous; whereas on inner planets you are effectively limited to the solidified skin at the bottom of an annoying gravity well, bathed in heat that must be shed. Kuiper belt distances are inconvenient only when you are in a hurry and have limited speeds. Given fusion propulsion, nothing inside a solar system is especially far from anything else. But a large volume to operate in, which grows as r^3, is valuable, and an unlimited sink of cold, moreso. If you need more mass, Neptune is right there.
  - m4rtink 6y ago
    Good point - the exposed surface are for easy mining is pretty massive for outer system objects & accessible without the need for advanced stuff like planet cracking and solar lifting.