My original musings were with industrial city states 100 km in diameter, based on concentric ring and sector ring models along with multiple nuclei models of cities. Such industrial city-states would be 100 km apart, and connected by railways with trains travelling from 100 km/hr to 200 km/hr, with cars travelling at 50 km/hr. In my initial musings had no consideration of population. I later read some articles on maximum sustainable population of earth and from the various values adopted 10 billion as a design limit. I don’t know if this is the limit, it is just useful for design has it is larger than the existing population. Setting population limit of the city states as 10 million people, then need a total of 1000 city-states to house the future world population.
When I first got a computer and spreadsheet software, one of the things I did was, input the population and area data from my 1976 world picture atlas, and mess around with population distributions. From this I adopted a limit of 4000 people/km2 for population density. I also adopted a limit of 2/3rds of the area of the city for infrastructure, and only 1/3rd for residential. This led to a block of land approximately 16m x 16m for each person.
Additionally, the 100km diameter city is divided into towns 10 km diameter. The towns divided into villages 1 km in diameter. The villages divided into estates 100m in diameter. Each estate is divided into spaces 10m in diameter.
None of these ideas necessarily fits together. Still it provides a model. Added to this is the more recent consideration of cells 5 km in diameter. Last night I found some extra data, and extended the tables from my previous posting, checking cells 1000 km, 500 km, 250 km, 100 km, 25 km and 5km. The following tables list some of these options.
Table 1: Number of 5 km Diameter Cells
| Area | Cells | |
| Region | km² | Number |
| World:Total | 510,072,000 | 25,977,754 |
| World: Sea | 361,132,000 | 18,392,302 |
| World: Land | 148,940,000 | 7,585,452 |
| Eurasia | 55,000,000 | 2,801,127 |
| Africa | 30,370,000 | 1,546,731 |
| South America | 17,840,000 | 908,584 |
| Canada | 9,984,670 | 508,515 |
| United States of America | 9,833,520 | 500,817 |
| China | 9,596,961 | 488,769 |
| Australia | 7,692,024 | 391,752 |
| European Union | 4,475,757 | 227,948 |
| India | 3,287,263 | 167,419 |
| Western Australia | 2,645,615 | 134,740 |
| Mexico | 1,972,550 | 100,461 |
| Queensland | 1,852,642 | 94,354 |
| Northern Territory | 1,420,970 | 72,369 |
| South Australia | 983,482 | 50,088 |
| New South Wales | 809,444 | 41,225 |
| France | 643,801 | 32,789 |
| Japan | 377,972 | 19,250 |
| Germany | 357,168 | 18,190 |
| United kingdom | 242,495 | 12,350 |
| Victoria | 237,639 | 12,103 |
| Brisbane | 15,826 | 806 |
| Sydney | 12,368 | 630 |
| Melbourne | 9,991 | 509 |
| Perth | 6,418 | 327 |
| Yorke Peninsula Council | 5,834 | 297 |
| Adelaide | 3,258 | 166 |
| Australian Capital Territory | 2,358 | 120 |
| Hobart | 1,696 | 86 |
| Canberra | 814 | 41 |
| District Council of the Copper Coast | 773 | 39 |
| Darwin | 112 | 6 |
Table 2: Number of 25 km Cells
| Area | Cells | |
| Region | km² | Number |
| World:Total | 510,072,000 | 1,039,110 |
| World: Sea | 361,132,000 | 735,692 |
| World: Land | 148,940,000 | 303,418 |
| Eurasia | 55,000,000 | 112,045 |
| Africa | 30,370,000 | 61,869 |
| South America | 17,840,000 | 36,343 |
| Canada | 9,984,670 | 20,341 |
| United States of America | 9,833,520 | 20,033 |
| China | 9,596,961 | 19,551 |
| Australia | 7,692,024 | 15,670 |
| European Union | 4,475,757 | 9,118 |
| India | 3,287,263 | 6,697 |
| Western Australia | 2,645,615 | 5,390 |
| Mexico | 1,972,550 | 4,018 |
| Queensland | 1,852,642 | 3,774 |
| Northern Territory | 1,420,970 | 2,895 |
| South Australia | 983,482 | 2,004 |
| New South Wales | 809,444 | 1,649 |
| France | 643,801 | 1,312 |
| Japan | 377,972 | 770 |
| Germany | 357,168 | 728 |
| United kingdom | 242,495 | 494 |
| Victoria | 237,639 | 484 |
| Brisbane | 15,826 | 32 |
| Sydney | 12,368 | 25 |
| Melbourne | 9,991 | 20 |
| Perth | 6,418 | 13 |
| Yorke Peninsula Council | 5,834 | 12 |
| Adelaide | 3,258 | 7 |
| Australian Capital Territory | 2,358 | 5 |
| Hobart | 1,696 | 3 |
| Canberra | 814 | 2 |
| District Council of the Copper Coast | 773 | 2 |
| Darwin | 112 | 0 |
Table 3: Number of 100 km Cells
| Area | Cells | |
| Region | km² | Number |
| World:Total | 510,072,000 | 64,944 |
| World: Sea | 361,132,000 | 45,981 |
| World: Land | 148,940,000 | 18,964 |
| Eurasia | 55,000,000 | 7,003 |
| Africa | 30,370,000 | 3,867 |
| South America | 17,840,000 | 2,271 |
| Canada | 9,984,670 | 1,271 |
| United States of America | 9,833,520 | 1,252 |
| China | 9,596,961 | 1,222 |
| Australia | 7,692,024 | 979 |
| European Union | 4,475,757 | 570 |
| India | 3,287,263 | 419 |
| Western Australia | 2,645,615 | 337 |
| Mexico | 1,972,550 | 251 |
| Queensland | 1,852,642 | 236 |
| Northern Territory | 1,420,970 | 181 |
| South Australia | 983,482 | 125 |
| New South Wales | 809,444 | 103 |
| France | 643,801 | 82 |
| Japan | 377,972 | 48 |
| Germany | 357,168 | 45 |
| United kingdom | 242,495 | 31 |
| Victoria | 237,639 | 30 |
| Brisbane | 15,826 | 2 |
| Sydney | 12,368 | 2 |
| Melbourne | 9,991 | 1 |
| Perth | 6,418 | 1 |
| Yorke Peninsula Council | 5,834 | 1 |
| Adelaide | 3,258 | 0 |
| Australian Capital Territory | 2,358 | 0 |
| Hobart | 1,696 | 0 |
| Canberra | 814 | 0 |
| District Council of the Copper Coast | 773 | 0 |
| Darwin | 112 | 0 |
Table 4: Number of 250 km Cells
| Area | Cells | |
| Region | km² | Number |
| World:Total | 510,072,000 | 10,391 |
| World: Sea | 361,132,000 | 7,357 |
| World: Land | 148,940,000 | 3,034 |
| Eurasia | 55,000,000 | 1,120 |
| Africa | 30,370,000 | 619 |
| South America | 17,840,000 | 363 |
| Canada | 9,984,670 | 203 |
| United States of America | 9,833,520 | 200 |
| China | 9,596,961 | 196 |
| Australia | 7,692,024 | 157 |
| European Union | 4,475,757 | 91 |
| India | 3,287,263 | 67 |
| Western Australia | 2,645,615 | 54 |
| Mexico | 1,972,550 | 40 |
| Queensland | 1,852,642 | 38 |
| Northern Territory | 1,420,970 | 29 |
| South Australia | 983,482 | 20 |
| New South Wales | 809,444 | 16 |
| France | 643,801 | 13 |
| Japan | 377,972 | 8 |
| Germany | 357,168 | 7 |
| United kingdom | 242,495 | 5 |
| Victoria | 237,639 | 5 |
| Brisbane | 15,826 | 0 |
| Sydney | 12,368 | 0 |
| Melbourne | 9,991 | 0 |
| Perth | 6,418 | 0 |
| Yorke Peninsula Council | 5,834 | 0 |
| Adelaide | 3,258 | 0 |
| Australian Capital Territory | 2,358 | 0 |
| Hobart | 1,696 | 0 |
| Canberra | 814 | 0 |
| District Council of the Copper Coast | 773 | 0 |
| Darwin | 112 | 0 |
Table 5: Number of 500 km Cells
| Area | Cells | |
| Region | km² | Number |
| World:Total | 510,072,000 | 2,598 |
| World: Sea | 361,132,000 | 1,839 |
| World: Land | 148,940,000 | 759 |
| Eurasia | 55,000,000 | 280 |
| Africa | 30,370,000 | 155 |
| South America | 17,840,000 | 91 |
| Canada | 9,984,670 | 51 |
| United States of America | 9,833,520 | 50 |
| China | 9,596,961 | 49 |
| Australia | 7,692,024 | 39 |
| European Union | 4,475,757 | 23 |
| India | 3,287,263 | 17 |
| Western Australia | 2,645,615 | 13 |
| Mexico | 1,972,550 | 10 |
| Queensland | 1,852,642 | 9 |
| Northern Territory | 1,420,970 | 7 |
| South Australia | 983,482 | 5 |
| New South Wales | 809,444 | 4 |
| France | 643,801 | 3 |
| Japan | 377,972 | 2 |
| Germany | 357,168 | 2 |
| United kingdom | 242,495 | 1 |
| Victoria | 237,639 | 1 |
| Brisbane | 15,826 | 0 |
| Sydney | 12,368 | 0 |
| Melbourne | 9,991 | 0 |
| Perth | 6,418 | 0 |
| Yorke Peninsula Council | 5,834 | 0 |
| Adelaide | 3,258 | 0 |
| Australian Capital Territory | 2,358 | 0 |
| Hobart | 1,696 | 0 |
| Canberra | 814 | 0 |
| District Council of the Copper Coast | 773 | 0 |
| Darwin | 112 | 0 |
Table 6: Number of 1000 km Cells
| Area | Cells | |
| Region | km² | Number |
| World:Total | 510,072,000 | 649 |
| World: Sea | 361,132,000 | 460 |
| World: Land | 148,940,000 | 190 |
| Eurasia | 55,000,000 | 70 |
| Africa | 30,370,000 | 39 |
| South America | 17,840,000 | 23 |
| Canada | 9,984,670 | 13 |
| United States of America | 9,833,520 | 13 |
| China | 9,596,961 | 12 |
| Australia | 7,692,024 | 10 |
| European Union | 4,475,757 | 6 |
| India | 3,287,263 | 4 |
| Western Australia | 2,645,615 | 3 |
| Mexico | 1,972,550 | 3 |
| Queensland | 1,852,642 | 2 |
| Northern Territory | 1,420,970 | 2 |
| South Australia | 983,482 | 1 |
| New South Wales | 809,444 | 1 |
| France | 643,801 | 1 |
| Japan | 377,972 | 0 |
| Germany | 357,168 | 0 |
| United kingdom | 242,495 | 0 |
| Victoria | 237,639 | 0 |
| Brisbane | 15,826 | 0 |
| Sydney | 12,368 | 0 |
| Melbourne | 9,991 | 0 |
| Perth | 6,418 | 0 |
| Yorke Peninsula Council | 5,834 | 0 |
| Adelaide | 3,258 | 0 |
| Australian Capital Territory | 2,358 | 0 |
| Hobart | 1,696 | 0 |
| Canberra | 814 | 0 |
| District Council of the Copper Coast | 773 | 0 |
| Darwin | 112 | 0 |
As can seen from the tables, 1000 industrial city-states, 100 km in diameter, is only a fraction of the total possible, and most countries have more than enough cells to match the number of city-states their current and future populations require.
The 1000 km cells represent the centres between stations supplied by diesel-electric trains supplying fuel to the interiors of land masses. Whilst the 500 km cells represent the centres between fuel service stations for road transport. The 25 km cells represent the centres between hotels, inns, and other public houses for people travelling on foot, walking from place to place. The 250 km diameter cells represent a potential operational radius of helicopters: that is they can travel 250 km between centres and return without need to refuel at the destination, but can refuel back at the point of origin. In other situations the 500 km centres hold.
As in previous posts the 5km cells represent a region one person can travel around in one day. And which also gives an indication of the number of environmental scientists, surveyors and civil engineers each country or the world needs. The counts of the other cells are useful for identifying the minimum numbers of other resources. For example the 500 km cells indicate a minimum of 759 vehicles: one for each cell to get to an adjacent cell. Each such cell requires a fuel depot.
I will hazard a guess there are more than 800 petrol stations in the world: however I also guess they are not distributed to provide access to the world: or even the interiors of continents. Which is not entirely a problem as I hazard a guess there is no need to travel more than 10,000 km across land, and at around 10 km/L need 1000 L fuel trailer tank. Such trailer doesn’t seem impractical and appears readily available: though carting such trailer is likely to increase fuel consumption and therefore reduce km/L. Still it’s just a matter of planning, and possibly working out the 10,000 km cells: the areas indicate 2 such cells for the land area, and 6 for the total area of the world.
Anycase, picking a diameter and an existing city and then drawing the circular cells with hexagonal close packing, provides something to work with, and then seek out geographical features which distort the simplified model. Alternatively triangulate existing city connections and draw bounding polygons.
As with previous essays, civilisation stops when the next inn is more than 25 km away. The assertion is that civilisation develops and extends outwards and radially from the first outpost in a region. The first outpost is an inn, a fuel station, and general supply store.