> But for a giant city, I actually don't know if that works, and it may be worse because you're generating so much heat that it's now harder to pump out. For examples like the urban heat island effect, where these cities generate massive amounts of waste heat, I actually don't know if that would work if it didn't apply the same way. I'm trying to reach back to my physics classes in college, so I'm not sure about the actual mechanics of that

Robin Hanson, perhaps surprisingly, has some material on that from his brain-upload work on modeling large datacenters, which have the same issue: you want them to be as small & dense as possible to minimize latency within them, but does that make it impossible to cool reasonably efficiently & prevent them from literally melting down? Apparently no, you can efficiently pipe fluids (and thus, heats) with fractal designs which scale slower than the economic value of very large/dense cities (and so can be paid for): https://www.overcomingbias.com/p/the-bright-future-of-pipeshtml

>> For example, there is a fractal design for piping both smoothly flowing and turbulent cooling fluids where, holding constant the fluid temperature and pressure as well as the cooling required per unit volume, the fraction of city volume devoted to cooling pipes goes as the logarithm of the city’s volume. That is, every time the total city volume doubles, the same additional fraction of that volume must be devoted to a new kind of pipe to handle the larger scale. The pressure drop across such pipes also goes as the logarithm of city volume.


>> The economic value produced in a city is often modeled as a low power (greater than one) of the economic activity enclosed in that city. Since mathematically, for a large enough volume a power of volume will grow faster than the logarithm of volume, the greater value produced in larger cities can easily pay for their larger costs of cooling. Cooling does not seem to limit feasible city size. At least when there are big reservoirs of cool fluids like air or water around.

citing as an example "Constructal tree network for fluid flow between a finite-size volume and one source or sink", Bejan 1997 https://gwern.net/doc/cs/1997-bejan.pdf ; Bejan et al 2000 https://gwern.net/doc/cs/hardware/2006-bejan.pdf ; Bejan 2006, _Advanced Engineering Thermodynamics_. This is covered in a bit more detail in the final book version, _Age of Em_, ch7 Logistics § Cooling.

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Oct 27, 2022·edited Nov 4, 2022Liked by Dwarkesh Patel

"(....) who made the point that the Industrial Revolution happened in Britain because the cost of labor was highest in Britain since there was a plague that killed up a bunch of people so labor was really expensive."

- Factories mainly employed women and young children. So I do not agree with the assessment. I think England was wealthier compared to the European Continent, as that was ravaged during of the Napoleonic wars.

"Software engineers typically earn a salary that falls within the range of $60,000 per year to $130,000 per year. It would be very unlikely for an entry-level software engineer to start out at a salary that exceeds this range. An exceptional high salary is not unheard of, even into the range of $200,000 per year or more." (source: Zippia.)

The high rise - yes looks great on artist impressions, doesn't it ! But who wants to live in one ? Who can live in one ? Multiple unit buildings need a lot of additional hardware: heating/cooling, elevators, sprinklers, safety doors, security systems, warning systems, refuse systems, etc. All of these need (a lot of) maintenance and regular updates/repairs. Common areas need cleaning too, continuously. Which means high additional costs on top of rent/mortgage/property taxes. Furthermore are the developers intending to tear down these buildings after 50 years ? After that many years the building will be seen as outdated and the rich who can afford to live in such a place will have moved on. That brings a next generation of less well-to-do as inhabitants. The amenities will start to break down, the building will become filthy and squalid. Without properly functioning elevators, families with kids will be able to live on the first 10, some young people can maybe do up to the 20th floor over the stairs. The rest of the building will attract squatters.

"Centrally planned cities or top-down planned cities never seem to do particularly well, right?" Maybe I misunderstand this, but Amsterdam is a city that was carefully planned each time it was enlarged (until the 60ies).

Much of the town I was born was also planned, neighborhoods with small houses for blue-collar workers, with red-tiled roofs, often small gardens front and back, and each house a shed for the bicycles etc. Small shops located at the end of a street, in the same style, same for the schools, the library. Each neighborhood had a slightly different character. The architecture was unassuming and yet it was "everyday beauty".

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Lots of interesting points, thanks Antoinette!

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> The other part of it is you can't really do that with a building. I guess I would also maybe say that if you're a developer, with a building, it's not necessarily obvious how it got to the point that it did when it was put together. A lot of times with physical things, even if you have the object, it is unclear what the process was to create it. So a lot of times what you see is that even with like this comes industrial espionage. Or somebody who's trying to steal some particular thing or whatever a lot of times that doesn't help them as much as they would think to try to like recreate it. A lot of times they have to basically go through the entire process of figuring out how to make it and it takes them just as long to do it as it did the original people doing the development. You saw this with like the development of the atomic bomb for instance. We're like the people who stole this stole the plans for how to make it or who had information on exactly how their system would react if the bomb worked basically took as long to figure out how to make it as the US did.

This seems historically false and a bad argument: the USSR did create the atomic bomb much faster than the USA had expected (by ~4 years!), and you would in fact expect them to take *much* longer than the USA did, because they were *much* poorer, had just spent a decade sending their intellectuals to the gulag, and then half of that decade fighting a war devastating half their country after an invasion (a little thing you might recall called 'WWII'). Other countries have historically taken much longer to make their atomic bombs: North Korea, for example, took decades from the initiation to first successful test (despite the advantage of Soviet technology transfers and about half a century of additional global science/technology & information leaks), and you could even argue that it took NK about 10x longer than the original Manhattan project depending on what preliminaries you count (https://en.wikipedia.org/wiki/Timeline_of_the_North_Korean_nuclear_program). Which is what you would expect from a small desperately poor nation, as opposed to one of the largest countries in the world by both population & GDP (and also wealth per capita).

So the fact that the USSR could whip out an atomic bomb (and then later a H-bomb) so quickly confirms that the nuclear spies really did do as much damage as they were thought to. The tacit knowledge is surely real, but also not so big a deal as to eliminate the enormous value of spies giving you debugged blueprints and documenting all the dead ends.

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