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07-28-2014, 10:58 PM
(This post was last modified: 07-28-2014, 10:59 PM by radtech497.)
While working in my sandbox (from which I have migrated versions of its inhabitants to OA after making alterations to fit that milieu), it occurred to me that at least one civilization residing there raises a question about the practice of classifying xenosophonts by their energy emissions.
That civilization, the Tleitylwesi, the most technologically advanced in the "Sandbox Volume," would be characterized as a Low Energy Emission Civilization as per the Energy Emissions and Civilization Types page of the EG. However, their civilization ranks in the upper parts of Type II on the Kardashev scale (if one is considering total energy used rather than Kardashev's original criteria of energy available for communication). They possess, among other things, wormholes (for point-to-point exchanges of bulk freight and data, with a minor trade in passenger craft), superluminal spacecraft for traveling outside their wormhole network, Dyson Bubbles surrounding each of their inhabited planetary systems cooled to nearly the cosmic background temperature of 2.77 Kelvin by utilizing the magnetocaloric effect, and a host of other advanced technologies.
The reasons for this apparent contradiction are rooted in the history and culture of the civilization: they do not wish to be discovered by any other civilization. This has led to a relatively small "empire" of less than 100 inhabited systems (enough to ensure their species' survival, but not enough to be particularly noticeable), and a technological bias toward increasing efficiencies in all aspects of their society.
That is not to say they cower within the safety of their Dyson Bubbles in abject fear of the "outer dark." Their civilization has long spent, and continues to expend, a nontrivial part of its resources on deploying small probes designed to detect other sophont civilizations. Once detected, the activities of such civilizations are closely monitored to determine whether or not they might pose a potential threat. If it is determined that a potential threat exists, the monitoring civilization will intervene to eliminate that threat.
BTW, this civilization is aware of Terragens, and their most recent encounter is (somewhat apocryphally) described in this GhostNet article.
Radtech497
"I'd much rather see you on my side, than scattered into... atoms." Ming the Merciless, Ruler of the Universe
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I don't think that a dyson sphere could be cooled to the CMBR temperature by refrigeration, however advanced; the energy would have to go somewhere. If the radiating surface were big enough then this would work, but then you have a very large object emitting large amounts of diffuse radiation.
On the other hand a very advanced civilisation could disguise itself in a number of other ways, or simply extend itself into an arbitrary number of baby universes, making them very tricky to spot. If the civilisation only used comm-gauge wormholes this could be a good disguise, although the process of making wormholes and baby universes is probably one that emits a significant amount of radiation.
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I don't know that you could cool dysons that far, but a Matrioshka brain could probably do it. If the radiation is diffuse enough that it blends into the CMBR, then you're good to go.
As far as how they would be classified - I would suggest that the energy emission classification is but one of several such systems in play in the setting for rapidly categorizing a civilization and giving a reader an idea of its characteristics. Carl Sagan discussed this in his book The Cosmic Connection, where he talked about both Kardashev energy levels, but also the amount of information would characterize a civilization, from the level of 20 questions (a Type A civ), to a civ of a million galaxies all operating as a cohesive civilization (Type Z - and impossible according to Sagan due to lightspeed limits - without wormholes). He also had a passing mention of something like this in the Cosmos episode/chapter titled Encyclopedia Galactica when describing the different civs shown in that episode.
I would imagine that Terragen civ has a variety of classification systems that, taken together, provide a reasonable snapshot description of a given civilization and its characteristics. It's energy emission level would only be one part of that.
Todd
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Magnetic refrigeration techniques are more than adequate for the task of cooling the exterior surfaces of a Dyson Bubble's statites. As described in this Wikipedia article, cooling materials to CMBR temperatures is almost trivial in comparison to temperatures reachable by RL technology. Given that all that is required are magnets, a suitable solid "refrigerant," and power, this seems achievable by any civilization capable of building Type III dysons (Type I are dyson swarms, Type II are dyson shells, and Type III are dyson bubbles).
Radtech497
"I'd much rather see you on my side, than scattered into... atoms." Ming the Merciless, Ruler of the Universe
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07-29-2014, 05:54 PM
(This post was last modified: 07-30-2014, 04:52 AM by stevebowers.)
Yes, but the radiating surfaces still have to be large enough to dump the heat. Perhaps you could cycle the waste heat out to the star's Oort cloud to radiate it there. But the star's total luminosity doesn't change, unless you engineer the star deliberately. In fact, if you are running a refrigeration system, that results in an increase in total waste heat emissions, rather than a decrease.
The 'EEC' part of the HEEC classification refers to the amount of energy each civilisation absorbs and re-emits, the temperature of that re-emission is only relevant to how easy they are to detect.
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(07-29-2014, 05:54 PM)stevebowers Wrote: Yes, but the radiating surfaces still have to be large enough to dump the heat. Perhaps you could cycle the waste heat out to the star's Oort cloud to radiate it there. But the star's total luminosity doesn't change, unless you engineer the star deliberately. In fact, if you are running a refrigeration system, that results in an increase in total waste heat emissions, rather than a decrease.
The 'EEC' part of the HEEC classification refers to the amount of energy each civilisation absorbs and re-emits, the temperature of that re-emission is only relevant to how easy they are to detect. I suspect that you are thinking that the radiator must be somewhere near the structure and/or external to it.
Why not just dump your waste down a wormhole, the far end of which is conveniently located to avoid suspicion?
Or into a black hole inside the megastructure? Any inconvenient gravitational radiation could be made to mimic that from naturally occurring objects.
I'm sure there must be other solutions to the waste heat problem.
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07-30-2014, 05:38 PM
(This post was last modified: 07-30-2014, 05:44 PM by stevebowers.)
Yes, wormhole or blackhole heat dumps would also work , as I hinted in this message.
http://www.orionsarm.com/forum/showthrea...45#pid8745
Quote:On the other hand a very advanced civilisation could disguise itself in a number of other ways, or simply extend itself into an arbitrary number of baby universes, making them very tricky to spot.
You can dump energy into black holes, making them bigger, or into wormholes or baby universes (via wormholes), but this affects the stability of the wormhole.
Using black holes as a heatdump is not really an option in a spaceship, so you can't use them for stealth; black holes are net emitters of energy until they reach the mass of a large asteroid. But you could dump heat into a comm-gauge wormhole, although a lot of one-way traffic would destabilise these small objects. If more mass/energy passes through a wormhole in one direction, then the 'in' mouth gains an excess of negative energy.
http://adsabs.harvard.edu/abs/1995PhRvD..51.3117C
However if the 'hole is of a grazer configuration then this stability issue does not seem to be a major problem, according to Adam's writeup, although I'm not sure why.
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One interesting possibility for a heatdump would be the core of a black-hole suprashell. The suprashell could be inhabited, but the civilisation could dump its waste heat back into the black hole. The inhabited portion could be surrounded by a second, refrigerated shell that radiates at CMBR temperatures, which dumps its own waste heat back into the hole.
Hmm; this might work - the black hole could be surrounded by a small fusion disk, generating enough energy to run the civilisation, the suprashell and the refrigeration system. All waste heat from these three systems could be dumped back into the black hole. Would this work, or am I dreaming? The minimum temperature of the whole system would be the black body temperature of the black hole itself, but since it is surrounded by a large radiating suprashell, that temperature could be lowered to CMBR values or beyond.
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07-30-2014, 06:02 PM
(This post was last modified: 07-30-2014, 06:05 PM by stevebowers.)
Any black hole larger than 0.0075 x Earth's mass will be colder than the CMBR, so could be used as a heat dump even without a suprashell.
http://xaonon.dyndns.org/hawking/
Perhaps this is the answer to the dark matter problem; the universe is filled with tiny artificial planets, each one refrigerated to background temperatures on the outside.
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(07-30-2014, 05:55 PM)stevebowers Wrote: One interesting possibility for a heatdump would be the core of a black-hole suprashell. The suprashell could be inhabited, but the civilisation could dump its waste heat back into the black hole. The inhabited portion could be surrounded by a second, refrigerated shell that radiates at CMBR temperatures, which dumps its own waste heat back into the hole.
Hmm; this might work - the black hole could be surrounded by a small fusion disk, generating enough energy to run the civilisation, the suprashell and the refrigeration system. All waste heat from these three systems could be dumped back into the black hole. Would this work, or am I dreaming? The minimum temperature of the whole system would be the black body temperature of the black hole itself, but since it is surrounded by a large radiating suprashell, that temperature could be lowered to CMBR values or beyond. Don't see why it shouldn't work.
As for stabilising a wormhole, send heat one way and matter the other. A few more gigatons of iron wouldn't make much difference to the inhabited end of the wormhole, even if it isn't cooled to 2.7K and dumped outside, yet the energy equivalent would support the present day human civilization for a billion years.
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