Most Efficient Use of Housing in a DeathStar like station

[Darth Wong]

I would tend to assume that the inhabitants of such a community would be more energy-efficient than present-day America.

For one thing, heating and air conditioning requirements would be far simpler, because there is no external environment outside each person's dwelling which varies in temperature from -30 degrees Celsius to +45 degrees Celsius. The whole system would presumably be designed with thermodynamics in mind, so the tropical part of the space habitat would be closer to the centre, and the cold-weather part of the habitat would be closer to the outside. These innate thermal gradients would allow people to live at a comfortable temperature while being able to experience warmer or colder temperatures as they choose by simply moving closer to or farther away from the centre, without needing to expend great amounts of energy on individual or family-scale HVAC.

Similarly, transportation would be much more energy-efficient: rather than highways and cars, all travel would probably be on some sort of elevator and rail system, and the vessel would presumably be laid out to minimize average travel distance requirements for basic amenities, entertainment, etc.

[Omeganian]

One thing that would be a pain in scaling up habitat spheres like this is getting rid of all the heat.

Of course, with SW tech, they can handle heat from firing the superlaser, so they can just magic it away. But if you didn't have that, heat management would be a huge pain for this thing.

Just consider geometry - the internal space grows faster than the surface area. You're filling all the internal space with a civilization, but they can only get rid of their heat through the surface.

(If they were solar powered, they'd only get heat through the surface too, so that'd limit the size but it'd be easier to balance. But, here, presumably they are using power reactors inside like the Death Star. Everything bit of energy it produces internally will have to be expelled to keep the temperature steady.)


Now, you could have the surface at a much higher temperature than inside to help radiate heat faster. You'll need some way to move it all around, but let's ignore that...


If we assume the sphere is a blackbody with a temperature below the melting point of iron, we can figure it will radiate at most about 300 kW / m^2. Multiply that by the surface area of a sphere and we get a power / radius ratio.

It needs to get rid of equal power as it uses internally. How can we get power / volume ratio? Assume a lot of shit, of course!

Assume there's 100 meter ceilings and about 50 square meters per person total (if my memory serves correctly, that's about what NASA studies said is a reasonable estimate for a space habitat surface area, including personal, shared public, and agricultural land. The deck height is pure ass.) Now we have person per cubic meter.

Also assume each person burns thereabouts 10 kW of power, on average - a number similar to America today. Now we have power per person. Multiply through to get power per cubic meter. Use volume of a sphere to get cubic meters from radius and we have two equations equal to each other. Solving for radius is now 8th grade math college freshman algebra, lol.

... and I got an upper limit radius of about 500 km. Hilariously, that coincidentally puts us in the ballpark of the Death Star II's size! Of course, there's shitloads of questionable assumptions there, and the thing would be glowing hot across it's entire surface...



Bottom line though, discounting heat disappearance magic tech, I looks like heat management is a killer problem for something so large and densely populated, just looking at conservation of energy.

Well, the DS probably had to bleed off much more heat after each shot (we're talking about something like a heavy TL per minute power levels).

I wonder, you know... with all the temperature conditioning on the station, just how popular is nudism going to be?

[Crossroads Inc.]

There is an assumption throughout sci-fi that no starship maintenance will ever require anything bigger than one man and a small toolkit (hence the famous "Jeffries tubes" in Star Trek), but that seems stupid and ignorant to me. It's as if the Star Trek writers thought that starship maintenance was like computer maintenance; nothing ever needs to be done other than adjusting something with a fancy electronic tuning fork.

I bet that most sci-fi writers have never done any maintenance that required more than that - switching a lightbulb, perhaps some minor plumbing, other stuff you can do around your house.
But if you have ever taken your car to a repair shop for a proper checkup, you'll already see that you will need heavy machinery and good access to repair it. Of course, that might not be a feasible solution on a spaceship outside of a spacedock - possibly yet another reason for the size of the Death Star, enough free space to allow proper access to all parts of the station. Seems like a desirable trait for an independent weapon platform to me.

Sci Fi writers are obsessed with making all things "personable" because they want their heros to be seen. So if you are fixing a starship it can't be done at a massive dry dock with house sized construction parts, no no. It has to be done inside the ships, with brave heros toiling away with wrenches and hammers and stuff!

One of the things that brought all of this was the fact that my friend recently started reading Fred Saberhagen's Berserker series, and the idea of a titanic, self aware undying moon sized starship appealed to him, largely since his own universe centers on an ancient civilization controlled by a 20,000yo AI. But something I remember from the book was a part where a human scout goes inside of the machines and comes across this massive hole running the course of it, inflicted by an ancient battle. Rather then fully repairing the hole, the Berserker left it largely open because it found it so useful for moving things around inside and do other repair work.

It is just one of those things that make you wonder how it is overlooked by others. As you scale up a ship, all aspects of a ship need to go up as well. A massive ships is going to have skyscraper sized components. generators, air scrubbers, water filters, generators, etc, these won't be something a crew of workers could fix and then go out for lunch, they would be building sized parts that will need good accessible space to repair or if needed remove and replace.

No matter how big the worldships ends up being, vast stretches of open corridors would be useful not just for maintenance but transportation as well I imagine.

Also,

The comments about putting different habitats in different locations to maximize efficacy is also something I had been thinking about earlier and makes a lot of sense.
Why go through the effort of heating or cooling a special habitat when you can using the ambient temperature to provide the same effect. The only extra energy needed would be to ensure areas did not become TOO hot or too cold.

As far as heat exchange goes I wonder if there isn't some way to use excess heat with the engines, venting the heat along side the engines out into space.

[Darth Tedious]

Of course, with SW tech, they can handle heat from firing the superlaser, so they can just magic it away. But if you didn't have that, heat management would be a huge pain for this thing.

IIRC, they didn't have any magic heat management tech, they had to use a rather plain thermal exhaust port to vent the heat into space. Many people have said it was a rather shitty design feature.
(slight sarcasm, it was a pretty fucking spectacular amount of energy they were dealing with, so the exhaust vent must have been working some kind of majick)
Of course, such a feature may not be as big of a problem on a House Star, assuming it isn't used for blowing up heavily populated planets and pissing off local insugencies with access to technical readouts.


Of course, if you're using the surface of the station as a radiator, there's a thought which occurs...

Instead of being a nice. innocent looking smooth ball like the Death Star, the Friendly Community Housing Star should have totally badarse looking fuckoff spikes of death all over it.

If you have a cone-shaped spike, with a 1km radius base, sticking out 5km (so ~5.1km slant height), the outer surface will be ~16km2. Put one of those babies in every 10km2 and you've more than doubled your surface area, and made your space station several orders of magnitude more evil-looking. Oh yes.

How much more would that buy us on the upper limit radius?

[Omeganian]

Of course, with SW tech, they can handle heat from firing the superlaser, so they can just magic it away. But if you didn't have that, heat management would be a huge pain for this thing.

IIRC, they didn't have any magic heat management tech, they had to use a rather plain thermal exhaust port to vent the heat into space. Many people have said it was a rather shitty design feature.
(slight sarcasm, it was a pretty fucking spectacular amount of energy they were dealing with, so the exhaust vent must have been working some kind of majick)
Of course, such a feature may not be as big of a problem on a House Star, assuming it isn't used for blowing up heavily populated planets and pissing off local insugencies with access to technical readouts.


Of course, if you're using the surface of the station as a radiator, there's a thought which occurs...

Instead of being a nice. innocent looking smooth ball like the Death Star, the Friendly Community Housing Star should have totally badarse looking fuckoff spikes of death all over it.

If you have a cone-shaped spike, with a 1km radius base, sticking out 5km (so ~5.1km slant height), the outer surface will be ~16km2. Put one of those babies in every 10km2 and you've more than doubled your surface area, and made your space station several orders of magnitude more evil-looking. Oh yes.

How much more would that buy us on the upper limit radius?

Well, a lot of the heat will be radiated onto the other spikes and onto the surface. I'm not sure it buys anything at all. Such a measure is good for RL radiators because they don't have to work in vacuum, and most of the heat is bled off through means other than radiation. You're better off just projecting an external shield some 5000 km away and bleeding the heat from there.

[Darth Wong]

How are you going to relocate the heat to this external shield 5000 km away?

The simplest way to resolve machinery heat dissipation is to simply assume some kind of very high performance insulating layer or space between the working parts and the rest of the ship. If the machinery part of the ship is at a constant 500 degrees C, that doesn't necessarily make conditions unlivable in the rest of the ship as long as there is sufficient isolation.

Traditionally, sci-fi designers would put the engines really far from the living quarters in their sketches and drawings, in order to solve this problem. But if you're going to rely on some magic-tech anyway, you might as well just assume that they have some kind of fantastic technology for creating that level of insulation without requiring long separation distances.

Of course, if the whole ship is a sphere with no big asymmetries, then it would look like this is impossible, but you could literally just say that one half of it is machinery, the other half is living space, and there is an insulating layer or shield between the two hemispheres.

That doesn't solve the problem of heat generation in the living quarters themselves, but that's a function of size and per-person energy use.

[Simon_Jester]

I wonder, you know... with all the temperature conditioning on the station, just how popular is nudism going to be?

Nudism doesn't correlate strongly with warm climates- ask anyone in the Muslim world, or India. It depends on social mores, which can evolve in pretty much any direction.

[Batman]

Plus this isn't a holiday resort, it's a battlestation. People have jobs to do, a lot of which are going to require pockets, belts, rank insignia, holsters, possibly backpacks, not to mention the people who need protective clothing (even with Wars technology an NBC proof string tanga is something of a stretch). Contrary to what the Barsoom novels may claim, regardless of climate something to clip you holster and sword sheath to (and stick some ornamental jewelry on if you're female) is not always enough.

[Omeganian]

How are you going to relocate the heat to this external shield 5000 km away?

The same way you are relocating the energy to hold it up.

[Darth Tedious]

How are you going to relocate the heat to this external shield 5000 km away?

The same way you are relocating the energy to hold it up.

You could have just said magic...

[Darth Wong]

How are you going to relocate the heat to this external shield 5000 km away?

The same way you are relocating the energy to hold it up.

Please clarify.

[Omeganian]

How are you going to relocate the heat to this external shield 5000 km away?

The same way you are relocating the energy to hold it up.

Please clarify.

If the shield holds at a distance away from a ship, is reinforced by the ship at a distance, and keeps up when the ship is moving (ST shields tend to do all that), that means it is somehow connected to the ship. Transfer the energy through that connection. And try not to think about it too much.

[Darth Wong]

The same way you are relocating the energy to hold it up.

Please clarify.

If the shield holds at a distance away from a ship, is reinforced by the ship at a distance, and keeps up when the ship is moving (ST shields tend to do all that), that means it is somehow connected to the ship. Transfer the energy through that connection. And try not to think about it too much.

Well, you certainly aren't thinking about it too much, because that doesn't make any sense. Even if the goddamned thing was connected with a physical pillar, you couldn't magically make all your waste heat go to it.

[Simon_Jester]

Plus this isn't a holiday resort, it's a battlestation. People have jobs to do, a lot of which are going to require pockets, belts, rank insignia, holsters, possibly backpacks, not to mention the people who need protective clothing (even with Wars technology an NBC proof string tanga is something of a stretch). Contrary to what the Barsoom novels may claim, regardless of climate something to clip you holster and sword sheath to (and stick some ornamental jewelry on if you're female) is not always enough.

I gather it's more like an apartment building, or an 'arcology' (for a less fanciful and more pragmatic example, imagine living and working in the John Hancock Center).

But yeah, that doesn't change things much- most people don't wear clothes purely for the sake of protection from the weather. There's modesty (customs, or just "I don't really want to be seen naked" because of body image), protection from physical impacts, scratches and chafing, having pockets as you say...

Honestly, nudism is something that would probably be unlikely to catch on in a human society outside of specialized 'reserves' where you're there for recreation and it doesn't matter that you're not dressed practically. It might be socially acceptable to go naked, even, but it wouldn't become common- though "not wearing a shirt" for both sexes could, I guess.

[Darth Wong]

Perhaps it would be instructive to remind our readers of a few laws of thermodynamics. These are admittedly dumbed-down paraphrased versions, but:

Zeroth Law of Thermodynamics (I know that sounds really stupid but that's its name): Heat flows from regions of high temperatures to regions of low temperatures.

First Law of Thermodynamics: Mass/energy remains constant over time in a closed system.

Second Law of Thermodynamics: Entropy increases over time in a closed system.

There is an obvious problem with the idea of creating a high-temperature radiator at great distance to vent off the vessel's energy: the heat will not "want" to flow from the vessel to the radiator. That would go against the preferred direction as per the zeroth law. There are tricks we use to make it seem as if we can violate the zeroth law, by using endothermic phase changes to draw heat into a coolant, which then goes somewhere else to change back and dump the heat (that's how an air conditioner works), but they don't actually violate that law so much as work around it locally. The heat is still, at all times, flowing from regions of higher temperature to regions of lower temperature.

If you're going to use some kind of coolant to transfer heat to the radiator, well, it's pretty impractical for the radiator to be 5000km away. If you're going to convert the heat into some sort of collimated beam to shoot at the radiator, well, it begs the question of how you reverse the entropy, and if you can, why you don't just shoot it into space or turn it into a weapon or engine. Seriously, once you achieve the technology necessary to simply beam heat to some distant location, why bother with the radiator? This Entropy Reversal Engine could be the foundation of your whole sci-fi tech base if you want it to be, but then you kind of need to make a big deal out of it. You can't just say that the heat magically flows to this radiator and act as if there are no ramifications of this.

[Count Chocula]

Well we have Peltier converters, which convert a small portion of heat into electricity. Truckers' fridges, yay! This is a bit of handwavium, but why not posit a more efficient heat to electricity conversion as extant in the SW verse? There are obviously limits or starships wouldn't need thermal vents, but for conversion of more modest thermodynamic loads in a residential section, it seems at least possible. Plus, the electricity converted could be used to power some part of the shields.

[Darth Wong]

Well, as I said, there are workarounds if you're local. But when you're talking about trying to move the heat 5000km away, those workarounds don't work any more. And they can create as many problems as they solve: such systems create more overall heat for the system. We don't really care about such things when we're talking about something like a Peltier cooler for a computer CPU, because we have plenty of ambient convective cooling for the system overall, so our primary concern is just spreading that heat out a bit. But when you have a system that's basically insulated on all sides (which is what a spacecraft is, since conduction and convection cooling are reduced to zero), any solution that generates more overall heat should be looked at warily.

[Count Chocula]

I agree. I am ASS-U-ME-ing that a SW super Peltier circuit would convert heat to electricity, which would provide a modicum of power to those shields 5,000km away; I disagree with the notion that shields could BE the heat radiators.

Another thought; if a DS-type station is made of a steel-like substance, it would be a hell of a cold sink in deep space. Perhaps all that excess heat generated by keeping a billion or more people alive would be better used to heat the spaceframe when it's far away from a local source of heat, like a sun. Keeping the heat to electricity motif, perhaps the waste heat when in deep space could be used as a partial supplement for electrical heating of the station's structure in its outer habitats/parks/farms etc, or to keep the water supply from freezing. I have absolutely no idea how any of this applies in hyperspace, however.

[Omeganian]

Plus this isn't a holiday resort, it's a battlestation. People have jobs to do, a lot of which are going to require pockets, belts, rank insignia, holsters, possibly backpacks, not to mention the people who need protective clothing (even with Wars technology an NBC proof string tanga is something of a stretch). Contrary to what the Barsoom novels may claim, regardless of climate something to clip you holster and sword sheath to (and stick some ornamental jewelry on if you're female) is not always enough.

I gather it's more like an apartment building, or an 'arcology' (for a less fanciful and more pragmatic example, imagine living and working in the John Hancock Center).

But yeah, that doesn't change things much- most people don't wear clothes purely for the sake of protection from the weather. There's modesty (customs, or just "I don't really want to be seen naked" because of body image), protection from physical impacts, scratches and chafing, having pockets as you say...

Honestly, nudism is something that would probably be unlikely to catch on in a human society outside of specialized 'reserves' where you're there for recreation and it doesn't matter that you're not dressed practically. It might be socially acceptable to go naked, even, but it wouldn't become common- though "not wearing a shirt" for both sexes could, I guess.

Well, I simply remembered Asimov's The Gods Themselves, where the Moon Colony had most people going naked or near so (panties were usually worn, but not necessarily). Of course, the 1/6 G helped.

[Crossroads Inc.]

Ok, after a week of retooling, reading and considering, coming back with a new design and fresh information.

One, going off mostly what Wong has said, I've tried to remake it into less of a "Station" and more of a ship. Largely to deal with heat venting and radiating...
The first one that surprised me was that a Sphere is actually a BAD idea for a massive moving ship since it means there is no easy out for heat, and all directions are the same distance from the Core. As Wong said the best solution is if half was machine and half was living. Well... Going off of that I came up with the following.



Yellow: Power Core
Orange: Power Conduits
Red: Drive Engines.

Basically changed the over all shape so that it would make it easy to push heat out from the core, funneling heat out into space and out through the engines.
Next is the "Open Spaces" that initially inspired the thread. "Desert" and hot areas are placed lower and closer to the Core. Colder areas placed near the edge and temperate areas placed near the middle top, but closer to the central Energy relay for heat. Another aspect of the change is separate the livable area from the work area. (note the size of the open spaces is purely representative, right now looking at spaces between 5 to 15km in diameter and about 500 meters to 1.5km in height.) Much of the "Dirty" jobs are placed in the lower section. Foundries, smelters, furnaces, Chemical plants, refineries, etc. Basically all facilities that may pose a great danger if there is an accident or something the puts out a lot of heat is located in the bottom half where heat is easier to git rid of or can be utilized for other facilities.

Something else...

Plus this isn't a holiday resort, it's a battlestation. People have jobs to do, a lot of which are going to require pockets, belts, rank insignia, holsters, possibly backpacks, not to mention the people who need protective clothing (even with Wars technology an NBC proof string tanga is something of a stretch). Contrary to what the Barsoom novels may claim, regardless of climate something to clip you holster and sword sheath to (and stick some ornamental jewelry on if you're female) is not always enough.

I gather it's more like an apartment building, or an 'arcology' (for a less fanciful and more pragmatic example, imagine living and working in the John Hancock Center).

But yeah, that doesn't change things much- most people don't wear clothes purely for the sake of protection from the weather. There's modesty (customs, or just "I don't really want to be seen naked" because of body image), protection from physical impacts, scratches and chafing, having pockets as you say...

Honestly, nudism is something that would probably be unlikely to catch on in a human society outside of specialized 'reserves' where you're there for recreation and it doesn't matter that you're not dressed practically. It might be socially acceptable to go naked, even, but it wouldn't become common- though "not wearing a shirt" for both sexes could, I guess.

Issue of Nudism aside, one thing I wanted to address was the idea that this is NOT a battle station. I know early on I kept using the term "DeathStar" in regards to this since, well, when you think of a Massive Ship/Station that is the first thing that comes to mind. But in truth, while not exactly a "Holiday station" it is designed as basically an oversized colony ship. Grated its freaken massive and heavily armed, but it still built for people. That said it would have to have a military presence on bored, if not just for self defense but to maintain order as well. I actually looked at how Macross did things, by having military ships escorting a civilian colony fleet. Granted that might be a bad example but obviously it is something to consider.

[Sriad]

In terms of population aiming big for a "worldship" that's intended to be a hologram of its civilization makes sense; it's been calculated (no, sorry, I don't recall where) that it would take a minimum of around 100,000,000 people to maintain the level of technology and affluence currently enjoyed in USA/Europe/ect from digging resources out of the ground up to making sports cars and developing new generations of CPUs.

Futuristic automation and AIs would presumably bring that number down, but if you need a reason for a ship to hold a whole buncha folks there it is.

[Number Theoretic]

I vaguely recall, that Charles Stross came up with that number. Or at least recited it, if someone else has calculated it before.

[avatarxprime]

Ok, after a week of retooling, reading and considering, coming back with a new design and fresh information.

One, going off mostly what Wong has said, I've tried to remake it into less of a "Station" and more of a ship. Largely to deal with heat venting and radiating...
The first one that surprised me was that a Sphere is actually a BAD idea for a massive moving ship since it means there is no easy out for heat, and all directions are the same distance from the Core. As Wong said the best solution is if half was machine and half was living. Well... Going off of that I came up with the following. *snip*

Your final design sure looks a lot like High Charity or the Celestial Being if you're going with a lower tech civilization. You can possibly use either as a reference to get started with making more fleshed out designs.

[Crossroads Inc.]

Interesting designs, never seen those before, But I can see the similarities. At 348km in diameters it is about the size of what we were planning on. In a way it almost is what we were working on, though far more militarized. Also seems to be largely a hollowed out planetoid, though the fact that it is mobile and can warp is damned impressive give HALO tech level.

[sirocco]

When I read the title of the thread, the first picture that came to my mind was the Cocoon world in Final Fantasy 13.

Cocoon is a Dyson shell, a hypothetical world which consists of a hollow shell surrounding a "sun" (in this case, the fal'Cie Phoenix) at its core, with the surface of the world being on the inside of the shell.

However this is probably not "hard scifi" enough for you...