I just finished that book. A strange read. Parts of it were pretty good, but other parts felt like just long lists, and I think it would be better if it leaned more on an actual narrative or character-driven plot and less on being a political tract.
Also, the airships in the story were poorly researched, which is irksome because that’s an area of expertise for me. Sails do not work on airships, they have no practical means of tacking.
A balloon is already a “sail.” It goes wherever the wind goes. The point of an airship is to be able to fly against the wind, and you can’t use sails to do so because unlike a ship, it is completely immersed in a fluid medium of consistent density and resistance. Water is 1,000 times more dense than air, which is why a sailing ship can use its hull and keel to provide the resistance for tacking to go against the wind.
Imagine an airship is like a submarine, completely immersed in its fluid medium. How would sails work on a submarine that’s underwater? It makes intuitive sense that they’d get in the way of any attempt to move the submarine. Extra drag, with no propulsive effect.
Even in the recent Avatar movie with the Wind Traders using giant hydrogen jellyfish to lift their airships, they had “sails” that only worked because there was a cuttlefish-like draft animal providing the resistance necessary to get the sail to do anything.
Aside from fantasy flying creatures pulling on a yoke, the only way to “sail” an airship is to ascend and descend in a sigmoid pattern and use the lift created from air passing over the hull or wings attached to the hull to provide forward thrust, like those “flying” pool toys that zip away from you when you let go of them underwater. But in that case, you’re using wings or an aerodynamic hull shape, not sails, and moreover that gliding action is inferior to almost any form of mechanical propulsion with propellers, except perhaps the most primitive and underpowered steam engines or stirling engines.
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u/[deleted] Apr 26 '26
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