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/tech/ - Technology

"Technology reveals the active relation of man to nature"
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File: 1693674101988-0.jpg (27.75 KB, 585x612, balloonship.jpg)

File: 1693674101988-1.jpg (22.89 KB, 613x530, airsub.jpg)

File: 1693674101988-2.jpg (35.61 KB, 1362x622, blimp-plane.jpg)


Veritasium made a video about "airships"

And it appears that he fell for the old airship-con. The con works by pretending that these things are analogues to ships floating on the ocean. But they aren't like ships at all. Ships sit between the boundary layer of two media, usually air and water. They're stuck in the vertical axis and can only move in 2 dimensions. That allows for a relatively simple control scheme and much optimization.

Air"ships" on the other hand should really be called Air-subs, because they behave more like submarines that move in at least 3 dimensions and usually only touch a single medium. They need a much more elaborate control scheme that leaves a lot less room for optimization. Why relatively intelligent people tend to get fooled by this is somewhat a mystery, even if you don't understand any of the physics. So called Air"ships" don't even look like ships, they look more like Submarines, and you don't need to fill ships with a special gas or liquid to make them float.

Submarines only have a few niche applications, like military, deep ocean research and suicide-cans for rich adventure tourists. Similarly Air-subs will also only have niche applications.

Veritasium says that there is potential for mass-cargo-transportation. But there isn't, all viable mass-cargo transportation methods have one thing in common, The ratio of cargo-to-vehicle skews very far towards cargo. Airsubs will never be able to do that. You'll always need a lot of Airsub for relatively little cargo. At least in earths relatively thin atmosphere. Maybe on Venus with it's dense atmosphere this would be viable, and Airsubs will have their day once we begin colonizing the upper atmosphere of Venus with sky-cities.

The reason why the idea of Airsubs is still so magical is because they promise "Free lift". Filling up lots of gasbags with hydrogen or helium probably isn't the way to get it. But there might be another way, that is derived from hot-air blimps. Hot-air-balloons and blimps use large fuel burners to heat up air inside a bag. Hot Air is lighter than cold air hence you get lift. Every airplane has a source of free heat, the waste heat from the propulsion engine. It might be possible to blend Air-planes and blimps in order to recover waste-heat and use it for free lift. The simplest version of a Blimplane is a modified piston-engine plane where the exhaust-pipe feeds into a overhead-mounted vaguely aerodynamically shaped hot-air-lift-bag. It'll be slower but more fuel efficient, and it'll probably be impossible to stall, and work on shorter runways. The hot-air bag will be much smaller than on a blimp, and cause less drag. A optimized version of a blimp-plane will be something with extra thick inflatable wings that are kinda stubby, similar to this: https://farside.link/invidious/watch?v=UiIXz-ehcZs


Veritasium did a "pure ideology" in his video when he declares that the market chose semi-trucks as the sweet-spot for cargo. That is a load of horse manure. The sweet-spot for cargo is trains, and the only reason why trains aren't moving virtually all land-cargo is because there was a intense political effort to undo much of the rail-network decades ago, because capitalists thought they'd get higher margins from trucking than rail-roads. This is capitalism favoring less efficient technology and becoming a fetter on the means of production.


I wonder if the recurring attempts to make air-ships happen are somehow related to high wealth inequality, because super rich people want a floating hotel room out of reach from the plebs

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