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I saw a documentary about Kowloon Walled City. It was nightmarish. > Kowloon Walled City was an ungoverned and densely populated de jure Imperial Chinese encl

I saw a documentary about Kowloon Walled City. It was nightmarish. > Kowloon Walled City was an ungoverned and densely populated de jure Imperial Chinese enclave within the boundaries of Kowloon City, British Hong Kong. Originally a Chinese military fort, the walled city became an enclave after the New Territories were leased to the United Kingdom by China in 1898. Its population increased dramatically following the Japanese occupation of Hong Kong during World War II. By 1990, the walled city contained 50,000 residents[1] within its 2.6-hectare (6.4-acre) borders. https://en.wikipedia.org/wiki/Kowloon_Walled_City https://en.wikipedia.org/wiki/Kowloon_Walled_City Fortunately, it was razed. There's a nice park there now. I sure am glad we're not mice! Between Kowloon and the Yukon there's a sweet spot of population density. (Yukon is one of the least populated but still nice places on Earth. Fewer than ~45,000 people in ~450,000km².) We have plenty of room on Earth. We could construct an artificial continent in the Pacific Ocean with a nice crinkly coastline and everyone could live at the beach.

jacquesm 4y ago
> We could construct an artificial continent in the Pacific Ocean with a nice crinkly coastline and everyone could live at the beach. I'm from that crappy little country that makes islands for other countries: outside of the continental shelves I highly doubt that you could reclaim land unless you feel like living at the bottom of a very, very deep hole in the ocean and somehow I don't think that's the proposition that will get people enthusiastic. Plenty of visitors already freak out when they learn that NL is in many places more than 10 meters below sea level, and that's with relatively mild coastal weather. If you were to create a dike 100's of meters high (and where would you get the material without making the hole even deeper?) it will end up as something that would qualify as the biggest man made structure without the slightest competition, including the Great Wall. This is engineering on a scale that is currently as far as I know impossible.
- aliqot 4y ago
  Curious how large a floating structure must be to defeat wave motion that threatens to pull it apart.
  - jacquesm 4y ago
    It would have to be stupendously large if you ever want to build inside it using ordinary building materials, otherwise it will be like living on a permanent earthquake.
    - carapace 4y ago
      Yeah, I wouldn't try to hold back the ocean, I mean more like a floating island the size of Texas or so. But really fractal/crinkly, so there's lots and lots of coastline on the "interior" of the island. The outer edge would buffer storms and high seas. I have no actual idea if this is possible or not. (IANAEngineer or anything like that, just a weirdo on the Internet.) You start with the Great Pacific Garbage Patch. That's a lot of carbon floating on hydrogen and oxygen and salt. You collect the salt, melt it, use that to oxidize the GPGP trash. (Molten Salt Oxidation[1]). Plastic is converted to synthesis gas ("a mixture of hydrogen and carbon monoxide"[2]). Exothermic reaction. Now you need a way to convert the syngas to struts and glue. (I have some ideas on that but they're even nuttier... In any event, syngas is pretty useful stuff.) Use the struts and glue to make large structures out of "octet" truss (space-filling tessellation of octahedrons and tetrahedrons) and just float on top of the water. Imagine an upside-down Frisbee shape with walls roughly 100m tall and a diameter of two or three kilometers. That would be a small prototype. Really the main motive would be to perform a kind of stunt just to get people to realize that we can build very large structures now. [1] https://en.wikipedia.org/wiki/Molten_salt_oxidation https://en.wikipedia.org/wiki/Molten_salt_oxidation [2] https://en.wikipedia.org/wiki/Syngas https://en.wikipedia.org/wiki/Syngas
      - jacquesm 4y ago
        I think you'd be better off building something like that above the ocean with the whole thing supported by piers anchored very deep. Otherwise sooner or later your structure will meet that one wave that it can't deal with and then it's game over. But even something supported by piers would be an amazing feat of engineering by our current standards, even a typical drilling platform that is embedded in the continental shelf is - up close - something to behold. What you are talking about is many, many orders of magnitude more complex, both from a materials science perspective as well as the engineering itself. The sea is a formidable enemy for anything that you intended to float on top of it, in the longer term if you don't sidestep the problem you'll end up with your structure as a submersible. One of the problems is that moving water is incredibly destructive, I've seen 8 cubic meter concrete blocks thrown about like confetti during a bad storm at the coast, and that's nothing compared to what you have to deal with on the open ocean. Have a look at that first image: https://www.alipobiolog.nl/wplog/natuur/na-de-storm-2/ https://www.alipobiolog.nl/wplog/natuur/na-de-storm-2/ That's what left after the impact of a 2x2x2 meter concrete block. These are used to reinforce the piers near IJmuiden, where I used to live and the force of the impact of the water will dislodge those blocks from the asphalt in which they are embedded and throw them over or onto the pier itself. That's approximately 15 tonnes and I have no idea how much force it would require to break them free from their surroundings. Then there is the problem of anchoring your structure. All of the air on the Western side of a floating structure would impinge on the height that the whole thing extends above the sea, turning it into a gigantic sail. Before long your structure would start to move and the mass may work against moving in the beginning, but once it picks up speed the whole thing turns into a giant moving obstacle, eventually crashing into the shore somewhere. If you don't want that you'll have to expend a fair bit of power or anchor it to the seabed somehow, and to withstand such force will require a lot of engineering. This will need to be maintained as well to offset it coming loose in places. On the whole I think the easiest way would be to take an ocean liner and stick it somewhere at an anchor but even that isn't going to be very pleasant without forward motion to counteract a storm (you want to be heading into a storm under power, not float around in it).
hungryforcodes 4y ago
It looked really interesting actually. I'm sorry I never had the chance to go there.
- carapace 4y ago
  It was nightmarish. The scene that stayed with me the longest was a person working. She was in a space the size of a small closet. There was a small pot of soupy dough and three hot plates. She scooped dough and poured it on the plates. When they were cooked she removed them and put them on a stack. Then she did it again. The narrator said she worked like that for fourteen hours every day, making mu shu pancakes for the restaurants in the city (Hong Kong.) That was it. That was her whole life. Slaving like a robot. It's good that they destroyed it.
  - twic 4y ago
    After they destroyed it, she presumably did the same job somewhere else, with better electrical safety but higher rent. Her job wasn't created by the walled city, it was created by the economic order of Hong Kong.
    - carapace 4y ago
      That's almost the point: China is a larger version of Kowloon. The Earth is a larger version of Kowloon. The Solar System is a larger version of Kowloon. The Milky Way Galaxy is a larger version of Kowloon... We are not mice. We have to decide what population density (and economic order) we will live with.
      - generalizations 4y ago
        > We have to decide what population density (and economic order) we will live with. What does that mean in this case, though? I don't want to put words in your mouth, but if you're saying we have to pick the density we're ok with, does that mean she just shouldn't exist?

jacquesm 4y ago

> We could construct an artificial continent in the Pacific Ocean with a nice crinkly coastline and everyone could live at the beach. I'm from that crappy little country that makes islands for other countries: outside of the continental shelves I highly doubt that you could reclaim land unless you feel like living at the bottom of a very, very deep hole in the ocean and somehow I don't think that's the proposition that will get people enthusiastic. Plenty of visitors already freak out when they learn that NL is in many places more than 10 meters below sea level, and that's with relatively mild coastal weather. If you were to create a dike 100's of meters high (and where would you get the material without making the hole even deeper?) it will end up as something that would qualify as the biggest man made structure without the slightest competition, including the Great Wall. This is engineering on a scale that is currently as far as I know impossible.

aliqot 4y ago
Curious how large a floating structure must be to defeat wave motion that threatens to pull it apart.
- jacquesm 4y ago
  It would have to be stupendously large if you ever want to build inside it using ordinary building materials, otherwise it will be like living on a permanent earthquake.
  - carapace 4y ago
    Yeah, I wouldn't try to hold back the ocean, I mean more like a floating island the size of Texas or so. But really fractal/crinkly, so there's lots and lots of coastline on the "interior" of the island. The outer edge would buffer storms and high seas. I have no actual idea if this is possible or not. (IANAEngineer or anything like that, just a weirdo on the Internet.) You start with the Great Pacific Garbage Patch. That's a lot of carbon floating on hydrogen and oxygen and salt. You collect the salt, melt it, use that to oxidize the GPGP trash. (Molten Salt Oxidation[1]). Plastic is converted to synthesis gas ("a mixture of hydrogen and carbon monoxide"[2]). Exothermic reaction. Now you need a way to convert the syngas to struts and glue. (I have some ideas on that but they're even nuttier... In any event, syngas is pretty useful stuff.) Use the struts and glue to make large structures out of "octet" truss (space-filling tessellation of octahedrons and tetrahedrons) and just float on top of the water. Imagine an upside-down Frisbee shape with walls roughly 100m tall and a diameter of two or three kilometers. That would be a small prototype. Really the main motive would be to perform a kind of stunt just to get people to realize that we can build very large structures now. [1] https://en.wikipedia.org/wiki/Molten_salt_oxidation https://en.wikipedia.org/wiki/Molten_salt_oxidation [2] https://en.wikipedia.org/wiki/Syngas https://en.wikipedia.org/wiki/Syngas
    - jacquesm 4y ago
      I think you'd be better off building something like that above the ocean with the whole thing supported by piers anchored very deep. Otherwise sooner or later your structure will meet that one wave that it can't deal with and then it's game over. But even something supported by piers would be an amazing feat of engineering by our current standards, even a typical drilling platform that is embedded in the continental shelf is - up close - something to behold. What you are talking about is many, many orders of magnitude more complex, both from a materials science perspective as well as the engineering itself. The sea is a formidable enemy for anything that you intended to float on top of it, in the longer term if you don't sidestep the problem you'll end up with your structure as a submersible. One of the problems is that moving water is incredibly destructive, I've seen 8 cubic meter concrete blocks thrown about like confetti during a bad storm at the coast, and that's nothing compared to what you have to deal with on the open ocean. Have a look at that first image: https://www.alipobiolog.nl/wplog/natuur/na-de-storm-2/ https://www.alipobiolog.nl/wplog/natuur/na-de-storm-2/ That's what left after the impact of a 2x2x2 meter concrete block. These are used to reinforce the piers near IJmuiden, where I used to live and the force of the impact of the water will dislodge those blocks from the asphalt in which they are embedded and throw them over or onto the pier itself. That's approximately 15 tonnes and I have no idea how much force it would require to break them free from their surroundings. Then there is the problem of anchoring your structure. All of the air on the Western side of a floating structure would impinge on the height that the whole thing extends above the sea, turning it into a gigantic sail. Before long your structure would start to move and the mass may work against moving in the beginning, but once it picks up speed the whole thing turns into a giant moving obstacle, eventually crashing into the shore somewhere. If you don't want that you'll have to expend a fair bit of power or anchor it to the seabed somehow, and to withstand such force will require a lot of engineering. This will need to be maintained as well to offset it coming loose in places. On the whole I think the easiest way would be to take an ocean liner and stick it somewhere at an anchor but even that isn't going to be very pleasant without forward motion to counteract a storm (you want to be heading into a storm under power, not float around in it).

hungryforcodes 4y ago

It looked really interesting actually. I'm sorry I never had the chance to go there.

carapace 4y ago
It was nightmarish. The scene that stayed with me the longest was a person working. She was in a space the size of a small closet. There was a small pot of soupy dough and three hot plates. She scooped dough and poured it on the plates. When they were cooked she removed them and put them on a stack. Then she did it again. The narrator said she worked like that for fourteen hours every day, making mu shu pancakes for the restaurants in the city (Hong Kong.) That was it. That was her whole life. Slaving like a robot. It's good that they destroyed it.
- twic 4y ago
  After they destroyed it, she presumably did the same job somewhere else, with better electrical safety but higher rent. Her job wasn't created by the walled city, it was created by the economic order of Hong Kong.
  - carapace 4y ago
    That's almost the point: China is a larger version of Kowloon. The Earth is a larger version of Kowloon. The Solar System is a larger version of Kowloon. The Milky Way Galaxy is a larger version of Kowloon... We are not mice. We have to decide what population density (and economic order) we will live with.
    - generalizations 4y ago
      > We have to decide what population density (and economic order) we will live with. What does that mean in this case, though? I don't want to put words in your mouth, but if you're saying we have to pick the density we're ok with, does that mean she just shouldn't exist?