Optimal size for domes and other structures

[farmerben]

What is the optimal size for domes and similar structures on Mars or on the Moon?  How would you approach the problem?  What are the constraining limits?

1.  Wind loading or other structural parameters on Mars, not applicable on the Moon.

2.  Manufacturing limited.  Being easier to manufacture a small sheet of glass than a large one, and so on for other components.  Pyramids would actually be much simpler and stronger to build than domes using aluminum and glass.

3.  Transport limited.  Components have to fit inside a fairing for interplanetary travel so that sets the size constraint.

4.  Human scale.  If you can fit everything you need into 100m2 then why build bigger?  Even for agriculture on Earth it's usually better to build several small greenhouses rather than one huge one.  

5.  Constrained only by imagination and budget.  Flying and jumping sports might become the most popular activities on the Moon.  So a humungous aerodrome is desirable for purely entertainment purposes.

[darthgently]

4 hours ago, farmerben said:

What is the optimal size for domes and similar structures on Mars or on the Moon?  How would you approach the problem?  What are the constraining limits?

1.  Wind loading or other structural parameters on Mars, not applicable on the Moon.

2.  Manufacturing limited.  Being easier to manufacture a small sheet of glass than a large one, and so on for other components.  Pyramids would actually be much simpler and stronger to build than domes using aluminum and glass.

3.  Transport limited.  Components have to fit inside a fairing for interplanetary travel so that sets the size constraint.

4.  Human scale.  If you can fit everything you need into 100m2 then why build bigger?  Even for agriculture on Earth it's usually better to build several small greenhouses rather than one huge one.  

5.  Constrained only by imagination and budget.  Flying and jumping sports might become the most popular activities on the Moon.  So a humungous aerodrome is desirable for purely entertainment purposes.

1, 3, 4, 5, Yes.

I question 2.  The center of larger flat panes would be weaker than smaller flat panes of glass of similar thickness so the more panes in the dome the better, within reason (the fewer joins between panes the better also).  I think the optimum would be about the number of panes in  a hemidodecahedron at least (6 panes).  If you mean a very small room sized pyramid then I could see that.

Edited December 16, 2024 by darthgently

[AckSed]

With regards to size, the psychological advantage of a wide-open space cannot be overstated.

Here's a company that makes 10-metre in diameter dome tents, 5metres high, with 80 square metre floor space: https://www.domecompany.com.au/dome-sizes/the-10-metre-dome/

Spoiler

As you can see, it's pretty big, yet it can be loaded on a pickup truck and assembled by hand. A 100m2 dome will be bigger still (11.3 metres in diameter), but you're right - it's probably good enough to give that sensation of space, air and light that people need if they're living in regolith-protected burrows.

Part of me also says that geodesic domes may be the most efficient structure, but the whole craze of dome-building in the 70s and 80s made the drawbacks when using them for living space apparent: your appliances and furnishings have to be custom-made, there's 'dead' space where the walls meet the floor and the acoustics are great for a concert hall, poor for privacy: https://earthtodome.com/2017/01/19/geodesic-dome-homes-the-good-the-bad-the-awesome/

However, there should absolutely be a park or botanical garden that isn't a dome. Think something like the Crystal Palace.

----

I can see one advantage for building domes and structures on Mars that Luna doesn't have: the atmosphere.

We know that Mars has elemental sulphur and enough iron for reinforcing steel rods. That says to me you could use sulphur concrete, and the atmosphere and much milder temperature range means that the binding agent - sulphur - won't sublimate off.

If you wanted to make normal cement (or edge-cases like magnesium cement or zinc oxychloride cement) there's the materials for that, too, and they will be able to absorb carbon dioxide as they crystallise. Probably a waste of water, but you could do it.

There is also plentiful carbon dioxide and some water; with chlorates also being a waste product when cleaning Martian regolith for use in greenhouse soil, that says to me 'PVC and polyethylene plastics for a vapour barrier and maybe even greenhouse windows'.

That's not to say Luna doesn't have its advantages. You're right about the Human Flying Dome. The Menace From Earth got it right the first time by making an attraction that everyone wants to experience, even the natives. It'd also be a good way to harvest water and carbon dioxide from visitor's breath. Tourists will go. "You mean it's free?" "Well, you've already paid for the ticket and brought water, food, your, er, waste and carbon, so yes."

The visitors will then experience the extra-splashy 0.1 G pool (don't ask where the water came from), the human Wall of Death, the human loop-de-loop track and the jungle gym. Though you'd have to have spotters who could tell when people overextend themselves, as they may feel light, but they are still overcoming inertia and working up a sweat - bad for the rich and unfit.

Edit: I had a brainwave: Lunar kung-fu. Re-enact The Matrix and old wuxia - in real life! Wall-running, diving through a window from 5 metres away, impossible rolls and flips, mid-air sword duels - you too can feel like a superhero!

Edited December 16, 2024 by AckSed

[farmerben]

I know a roofer who shingled a geodesic dome "once".  Key word "once".

[magnemoe]

18 minutes ago, AckSed said:

With regards to size, the psychological advantage of a wide-open space cannot be overstated.

Here's a company that makes 10-metre in diameter dome tents, 5metres high, with 80 square metre floor space: https://www.domecompany.com.au/dome-sizes/the-10-metre-dome/

  Hide contents

As you can see, it's pretty big, yet it can be loaded on a pickup truck and assembled by hand. A 100m2 dome will be bigger still (11.3 metres in diameter), but you're right - it's probably good enough to give that sensation of space, air and light that people need if they're living in regolith-protected burrows.

Part of me also says that geodesic domes may be the most efficient structure, but the whole craze of dome-building in the 70s and 80s made the drawbacks when using them for living space apparent: your appliances and furnishings have to be custom-made, there's 'dead' space where the walls meet the floor and the acoustics are great for a concert hall, poor for privacy: https://earthtodome.com/2017/01/19/geodesic-dome-homes-the-good-the-bad-the-awesome/

However, there should absolutely be a park or botanical garden that isn't a dome. Think something like the Crystal Palace.

----

I can see one advantage for building domes and structures on Mars that Luna doesn't have: the atmosphere.

We know that Mars has elemental sulphur and enough iron for reinforcing steel rods. That says to me you could use sulphur concrete, and the atmosphere and much milder temperature range means that the binding agent - sulphur - won't sublimate off.

If you wanted to make normal cement (or edge-cases like magnesium cement or zinc oxychloride cement) there's the materials for that, too, and they will be able to absorb carbon dioxide as they crystallise. Probably a waste of water, but you could do it.

There is also plentiful carbon dioxide and some water; with chlorates also being a waste product when cleaning Martian regolith for use in greenhouse soil, that says to me 'PVC and polyethylene plastics for a vapour barrier and maybe even greenhouse windows'.

That's not to say Luna doesn't have its advantages. You're right about the Human Flying Dome. The Menace From Earth got it right the first time by making an attraction that everyone wants to experience, even the natives. It'd also be a good way to harvest water and carbon dioxide from visitor's breath. Tourists will go. "You mean it's free?" "Well, you've already paid for the ticket and brought water, food, your, er, waste and carbon, so yes."

The visitors will then experience the extra-splashy 0.1 G pool (don't ask where the water came from), the human Wall of Death, the human loop-de-loop track and the jungle gym. Though you'd have to have spotters who could tell when people overextend themselves, as they may feel light, but they are still overcoming inertia and working up a sweat - bad for the rich and unfit.

Edit: I had a brainwave: Lunar kung-fu. Re-enact The Matrix and old wuxia - in real life! Wall-running, diving through a window from 5 metres away, impossible rolls and flips, mid-air sword duels - you too can feel like a superhero!

Now you could make an huge park by merging multiple domes. Or build up walls who hold it up. This will work on Mars, 
On the moon you have radiation and micro meteoroids so you want something more protected as in underground or covered by rocks, water also works and is transparent but is heavy. 
Weirdly larger domes might be safer as an breach will be far away and its lots of air to get lost so it would had be be one serious breach to not give many minutes to evacuate. You would sleep underground anyway. 

And the fun factor like water running and an 1/10 g jungle gym would be major selling points but I guess you could build this cheaper in LEO. Now the moon is the genuine and classy thing while the cheap LEO parks are ripoffs. 

[darthgently]

23 minutes ago, magnemoe said:

Now you could make an huge park by merging multiple domes. Or build up walls who hold it up. This will work on Mars, 
On the moon you have radiation and micro meteoroids so you want something more protected as in underground or covered by rocks, water also works and is transparent but is heavy. 
Weirdly larger domes might be safer as an breach will be far away and its lots of air to get lost so it would had be be one serious breach to not give many minutes to evacuate. You would sleep underground anyway. 

And the fun factor like water running and an 1/10 g jungle gym would be major selling points but I guess you could build this cheaper in LEO. Now the moon is the genuine and classy thing while the cheap LEO parks are ripoffs. 

Here is water running over a toroidal geodesic.  How thick would the water layer need to be to provide shielding?  On the moon you’d need a double layer to contain the water

https://www.explore.com/1413186/fly-into-jewel-changi-airport-singapore-largest-indoor-waterfall/

47 minutes ago, farmerben said:

I know a roofer who shingled a geodesic dome "once".  Key word "once".

Yeah, shingling domes is not the way to go.  Just make the panes and joins water tight on earth

[tater]

Wind loading is not an issue on Mars until the size gets pretty huge I would imagine.

Given that radiation protection is important, and the only good mechanism is regolith, what are you thinking? I read "dome" as transparent. Would it be rec space (and farming) that people visit briefly, then perhaps habitation is buried on the outer circle of the dome, looking in (giving a view of green)—so a dome on top if a cylinder, where the windows in the cylinder look inwards)? Maybe some structures inside (like buildings on Earth) that have shielding on top, so that people transit through green space to shielded structures within, but it feels earth like?

[darthgently]

I only pictured ag domes at first but then water shielding came up and I recalled the water covered dome in Singapore.  So now I’m  picturing double layer geodesic domes of clear glass with frozen ice shielding between the layers; so a translucent igloo instead of regolith for shielding.  Would be much more livable.

Would need to be able to handle both liquid and ice phases though on Moon, but could really work well on Moon where heat capacity and phase transition could help mitigate temperature fluctuations perhaps.

Meteors still a problem so an early warning system and subterranean retreat a necessary option.  But the daylight would be a huge plus

Edited December 16, 2024 by darthgently

[darthgently]

What open source Linux software would allow me to model the loads of a double layer aluminum and glass geodesic with a variable thickness of liquid water and solid ice in between?  Only the inner layer would be load bearing but the outer layer would support itself I figure.

On Mars the ice itself would be load bearing like an igloo.  On the Moon, liquid water would probably need to be accommodated and support pillars may be required even in lunar gravity.  Might even need to accommodate water vapor expansion on the sunny side on the Moon; not sure.

[Nuke]

you know you can build origami structures,  weld them and turn them into spheres with explosives.

process does require water though. that said you only have to hold one atmosphere of pressure and these could probibly hold many times that. a process for manufacturing reinforced concrete domes could also be used. there is one process where you lay your concrete flat and inflate a bladder to domify it, but i cant find video. other proceses involve having an inflated volume, building a rebar cage around it, and then pouring on the concrete. again water required.

having prefab aluminum triangles with brackets welded on so you can connect them with bolts or some other fastener. id have these on the outside (also makes them stackable for transport) so you can coat the interior with several layers of resin. you can also have tiles with windows and airlocks that fit the pattern as well as a foundation plate. thing is you just need to build one, equiped for the production of the tiles. you could probibly stamp them from sheet stock with just a die press.

really i think its a matter of putting a starship on its side, removing the tank bulkheads (or perhaps build them with hatches welded to them so you can just cut out a section of bulkhead plate and have a door and rooms and need not mod the tanks). just build the ship with hab conversion in mind. engines can be removed, put into storage for spares on other ships. tanks can also be used to store water or other liquid/gaseous consumables. bonus if equipped with dome manufacturing equipment.

3 hours ago, farmerben said:

I know a roofer who shingled a geodesic dome "once".  Key word "once".

you see a lot of those on your way into the alaskan interior. saw at least half a dozen on a drive to fairbanks once.

Edited December 16, 2024 by Nuke

[AckSed]

1 hour ago, darthgently said:

What open source Linux software would allow me to model the loads of a double layer aluminum and glass geodesic with a variable thickness of liquid water and solid ice in between?  Only the inner layer would be load bearing but the outer layer would support itself I figure.

On Mars the ice itself would be load bearing like an igloo.  On the Moon, liquid water would probably need to be accommodated and support pillars may be required even in lunar gravity.  Might even need to accommodate water vapor expansion on the sunny side on the Moon; not sure.

Can it be done with mathematics? Going to try.

Random site I found says:

Quote

The hydrostatic force on a submerged dome can be calculated using the formula F = ρghA, where:

ρ is the density of the fluid (1000 kg/m3 for water at 4 deg. C, 922.4 kg/m3 for ice at -60 deg. C);

g is the gravitational acceleration (1.625 m/s2 for Luna, 3.72076 m/s2 for Mars);

h is the height of the fluid above the dome (we will assume 1 metre);

A is the surface area of the dome in contact with the fluid (Surface Area (m²) = 2 × π × Radius (m) × Height (m)).

This gives the force in Newtons per m2, or Pascals.

Reference: https://www.physicsforums.com/threads/hydrostatic-force-on-a-submerged-dome.538016/

For the dome with 11.3 m diameter, 5.65m radius and 100m2 of floor area, and assuming radius = height, that's an area of 200.58 m2. Punch that in...

Water dome on Mars: 1000 * 3.72 * 1 * 200.58 = 746,158N/m2

Water dome on Luna: 1000 * 1.625 * 1 * 200.58 = 325,943N/m2

On Mars, the temperatures measured in e.g. Gale Crater can range from 20 deg. C all the way down to -84 deg. C... in summer. In winter, knock 20-30 degrees off each of those. Mars gets cold. The dust storms are no fun, either, blocking up to 99% of light. Water stays ice, most of the time.

On Luna, it ranges from -173 deg. C to 116 deg. C at the equator. The water might boil.

 

[Fizzlebop Smith]

4 hours ago, tater said:

Wind loading is not an issue on Mars until the size gets pretty huge I would imagine.

Given that radiation protection is important, and the only good mechanism is regolith, what are you thinking? I read "dome" as transparent. Would it be rec space (and farming) that people visit briefly, then perhaps habitation is buried on the outer circle of the dome, looking in (giving a view of green)—so a dome on top if a cylinder, where the windows in the cylinder look inwards)? Maybe some structures inside (like buildings on Earth) that have shielding on top, so that people transit through green space to shielded structures within, but it feels earth like?

I often entertain similar thoughts. Underground seems tp be easier than surface spanning structures. 

Those elements which provide engineering hurdles here on earth would be largely absent. The relative Kip on a specific connection has to have calcs for all forms of stress: sheer, axial, etc.

I often wonder the degree of overengineering that would go into those first fee structures. We should send some drones that are capable of building small scale demonstration tools that observe some of these forces over time.

We are learning more and more about protein reaction and biological nano machines with singular purpose.  When will we reach the point where we can spray a hole?

I imagine some combination of both designs. Habitation would be underground with polymer coatings to prevent escaping gas bleeding through porous substrate.

Reservoir of water would act as secondary shielding. I'm hoping that fabrics continue to be innovated and pioneered.

Some interesting strides on textile habitable. No clue what these stresses and load transfers would look like on another planet. Things like wind & snow / rain fall have huge impact on local codes. I wonder what the Martian Public Work book would look like.

 

Edited December 16, 2024 by Fizzlebop Smith

[darthgently]

5 hours ago, AckSed said:

Can it be done with mathematics? Going to try.

Random site I found says:

For the dome with 11.3 m diameter, 5.65m radius and 100m2 of floor area, and assuming radius = height, that's an area of 200.58 m2. Punch that in...

Water dome on Mars: 1000 * 3.72 * 1 * 200.58 = 746,158N/m2

Water dome on Luna: 1000 * 1.625 * 1 * 200.58 = 325,943N/m2

On Mars, the temperatures measured in e.g. Gale Crater can range from 20 deg. C all the way down to -84 deg. C... in summer. In winter, knock 20-30 degrees off each of those. Mars gets cold. The dust storms are no fun, either, blocking up to 99% of light. Water stays ice, most of the time.

On Luna, it ranges from -173 deg. C to 116 deg. C at the equator. The water might boil.

 

Pretty sure a submerged dome would be quite a bit different than a double layer dome with water between layers, but that looks like an interesting start

[kerbiloid]

20 hours ago, farmerben said:

What is the optimal size for domes and similar structures on Mars or on the Moon?  How would you approach the problem?  What are the constraining limits?

The helmet diameter + 2 inches, to stick the head out from the underground vault and have a look around, without scratching the glass with ears.

20 hours ago, farmerben said:

1.  Wind loading or other structural parameters on Mars, not applicable on the Moon.

The dust will make the glass opaque very quickly, by sticking to and by scratching.

20 hours ago, farmerben said:

2.  Manufacturing limited.  Being easier to manufacture a small sheet of glass than a large one, and so on for other components.  Pyramids would actually be much simpler and stronger to build than domes using aluminum and glass.

Geodesic grid from the Kethane mod.

20 hours ago, farmerben said:

3.  Transport limited.  Components have to fit inside a fairing for interplanetary travel so that sets the size constraint.

No need/possibility to carry the glass from the Oerth. Brilliants  sitalls are the best girls' friends (c).

Spoiler

Are the by-products of the same lunar metallurgy from the pdf,  ecranized on the AnthroFuturism youtube.

20 hours ago, farmerben said:

4.  Human scale.  If you can fit everything you need into 100m2 then why build bigger?  Even for agriculture on Earth it's usually better to build several small greenhouses rather than one huge one.  

Crops scale, unless you are farming humans.

Still doesn't need a dome. Maybe, some geodesic gothic-like arch right above the head.

Spoiler

 

20 hours ago, farmerben said:

5.  Constrained only by imagination and budget.  Flying and jumping sports might become the most popular activities on the Moon.  So a humungous aerodrome is desirable for purely entertainment purposes.

Wings + pool to jump from top and troll the swimmers with tsunami.

Also, here on the DirthEarth we have 1000 g/cm² of protection above the head, and so you need for permanent presence on the Moon/Mars.

This means up to 10 t/m², or up to 4 m thick layer of glass.

Actually, this means that any habitat must be a thick concrete structure with pressurized metal cans in hollow cells, with only greenhouses and solar panels outside. The base from the Iron Sky is actually the most/only viable design of the extraterrestrial base (including the road with street lights).

And no greenhouse/solar panel can require more that several meters of height, because everything below will be in the shadows.

Spoiler

 

 

Edited December 17, 2024 by kerbiloid

[farmerben]

Pavonis Mons is my favorite location for a Mars base.  The caldera is 47 km across and 5 km deep.  I wonder if it is possible to glaze over something that large.

More likely you would have many small greenhouses on the floor of the caldera.  And a ring of habitable city carved into the cliff faces.  Then every house could have a horizontal window allowing sunlight, yet very good radiation shielding naturally built in.  A spaceport sits atop the caldera just to the south, and a road leads east the Valles mariners. 

[tater]

12 minutes ago, farmerben said:

Pavonis Mons is my favorite location for a Mars base.  The caldera is 47 km across and 5 km deep.  I wonder if it is possible to glaze over something that large.

More likely you would have many small greenhouses on the floor of the caldera.  And a ring of habitable city carved into the cliff faces.  Then every house could have a horizontal window allowing sunlight, yet very good radiation shielding naturally built in.  A spaceport sits atop the caldera just to the south, and a road leads east the Valles mariners. 

This was a concept from a competition for excavating Central Park in NYC, exposing the natural rock, then having housing, etc, forming the walls (the top floor is below street level).

https://www.dezeen.com/2016/03/28/new-york-horizon-yitan-sun-jianshi-wu-evolo-skysraper-competition-conceptual-skyscraper-central-park-new-york-architecture-landscape-urbanism/

So a crater forming the central depression, lined with habitat, and domed over.

Decades ago I was fascinated by megastructures/arcologies. They're sorta dystopian on Earth, but they are literally the only way on places like Mars.

[Nuke]

urbanites always need fake nature a few minutes drive away, i never really understood that. i can just go out side and get the real thing.

probibly necessary on mars because i can imagine the requirements for basic life support being more than a single individual can handle. so prospects for being a cave dwelling hermit on mars are not great.

Edited December 17, 2024 by Nuke

[magnemoe]

1 minute ago, Nuke said:

urbanites always need fake nature a few minutes drive away, i never really understood that. i can just go out side and get the real thing.

In very large cities it might be an long drive, luckily we don't have huge cities here in Norway. 

But we have winters with snow who can look pretty but tend to be an pain and is cold.  

[tater]

I think on Mars 2 different kinds of views are acceptable, but greenery is incredibly important for humans—even just knowing that you can "go outside" and it feels like outside, even though it's fake makes a difference. Since the agricultural areas need to exist anyway, leveraging the benefits to human wellbeing by facing habitat into them seems like a no-brainer to me.

[magnemoe]

On 12/16/2024 at 7:42 PM, Nuke said:

you know you can build origami structures,  weld them and turn them into spheres with explosives.

process does require water though. that said you only have to hold one atmosphere of pressure and these could probibly hold many times that. a process for manufacturing reinforced concrete domes could also be used. there is one process where you lay your concrete flat and inflate a bladder to domify it, but i cant find video. other proceses involve having an inflated volume, building a rebar cage around it, and then pouring on the concrete. again water required.

having prefab aluminum triangles with brackets welded on so you can connect them with bolts or some other fastener. id have these on the outside (also makes them stackable for transport) so you can coat the interior with several layers of resin. you can also have tiles with windows and airlocks that fit the pattern as well as a foundation plate. thing is you just need to build one, equiped for the production of the tiles. you could probibly stamp them from sheet stock with just a die press.

really i think its a matter of putting a starship on its side, removing the tank bulkheads (or perhaps build them with hatches welded to them so you can just cut out a section of bulkhead plate and have a door and rooms and need not mod the tanks). just build the ship with hab conversion in mind. engines can be removed, put into storage for spares on other ships. tanks can also be used to store water or other liquid/gaseous consumables. bonus if equipped with dome manufacturing equipment.

you see a lot of those on your way into the alaskan interior. saw at least half a dozen on a drive to fairbanks once.

Pooop  

Yes for first moon bases, land custum SS with living area with decks for then you lay it down, hatch to the upper tank, this has steel decks but is more for storage / workshops. At least for a couple, remove engines for reuse have an spare rear dome with an huge hatch you can drive pressurized rovers, even drill rigs and mining equipment into the garage for repairs and maintenance, insulation on outside but this need to be a bit sturdy.
Other tanks for fun including the pool  You clear area, land SS, dig an trench and lower it into it, then connect to  the others also removing engines and other relevant systems. Cover it with regolit. 
Many cargo SS will get cut up for the steel. 

 

[farmerben]

47 minutes ago, tater said:

This was a concept from a competition for excavating Central Park in NYC, exposing the natural rock, then having housing, etc, forming the walls (the top floor is below street level).

https://www.dezeen.com/2016/03/28/new-york-horizon-yitan-sun-jianshi-wu-evolo-skysraper-competition-conceptual-skyscraper-central-park-new-york-architecture-landscape-urbanism/

So a crater forming the central depression, lined with habitat, and domed over.

Decades ago I was fascinated by megastructures/arcologies. They're sorta dystopian on Earth, but they are literally the only way on places like Mars.

That looks pretty dystopian to me.  Cities are organic things that need to grow, decay, and regenerate...  If the whole thing is the same it will all go into decay at the same time.  

I think you must have private property in which people own, choose, and make their own stuff.  I think rich martians should have their own cavernous house and 100m2 greenhouse 

Edited December 17, 2024 by farmerben

[tater]

15 minutes ago, farmerben said:

That looks pretty dystopian to me.  Cities are organic things that need to grow, decay, and regenerate...  If the whole thing is the same it will all go into decay at the same time.  

I think you must have private property in which people own, choose, and make their own stuff.  I think rich martians should have their own cavernous house and 100m2 greenhouse 

Eventually. I think initial attempts will have to be more centrally planned, followed by more distributed habitation. 
 

The nyc thing above was a competition exercise, nothing that would actually ever be considered.
 

[magnemoe]

13 minutes ago, farmerben said:

That looks pretty dystopian to me.  Cities are organic things that need to grow, decay, and regenerate...  If the whole thing is the same it will all go into decay at the same time.  

I think you must have private property in which people own, choose, and make their own stuff.  I think rich martians should have their own cavernous house and 100m2 greenhouse 

The thing who stuck me was no balcony, here in Norway all city blocks have them, exception is the old ones downtown and this is Norway where you will use it for 1/3 of the year. My block is 50 years old and it had them enlarged. Looking at modern cruise ships I say this is an trend. 
 

[AckSed]

The thing is, an organic, livable city on Mars starts to bring up questions of "What is perceived as an organic, livable city on Earth?"

In my opinion, it should not be based around the car. That, and zoning laws, isolate people inside their castles, moated by your lawns, and bubble you in your pickup truck. It is ridiculous how large American houses are. Public transport should be cheap & available.

Walkable streets, large communal spaces, modest living quarters. That's part of the recipe. Not the whole one, I don't have all the answers, but part of it.

Edited December 17, 2024 by AckSed

[farmerben]

Just now, magnemoe said:

The thing who stuck me was no balcony, here in Norway all city blocks have them, exception is the old ones downtown and this is Norway where you will use it for 1/3 of the year. My block is 50 years old and it had them enlarged. Looking at modern cruise ships I say this is an trend. 
 

Another good reason to develop a crater 47 km in diameter 5 km tall.  You can have a million glazed balcony/greenhouses, attached to a living room with horizontal natural light, attached to deeper rooms for sleeping etc.  If citizens get  rich they could afford to burrow farther and carry the material out their front door.  

I would agree you need central planning for the first 5000 people or so.  But to reach a million people (and not be dystopia) you need elements of capitalism.