Activity for Eth‭

Type	On...	Excerpt	Status	Date
Question	—	Foldable, multipart helicopter blades What would it take to build helicopter blades that can fold in several parts? This is the continuation of a question on Aviation. Unfortunately, there have been no use case for this for existing helicopters, so no-one has spent millions trying to work out if it was possible, let alone how to do it. ... (more)	—	over 5 years ago
Question	—	How high can a Victorian-era kite sail be flown? A big problem with Steampunk airships is how to propel them. Steam engines tend to be too heavy to be useful. And sails cannot be used, because unlike sea-going ships, airships are in contact with only one medium - they don't have the sea to push against. A clever proposal that sometimes come up is ... (more)	—	over 5 years ago
Question	—	How quiet can a static, non-propulsive pulsejet be? The wizards of Magitechia have discovered that the deflagration or detonation of certain chemical compounds have beneficial supernatural effects, that are useful for powering magical apparatuses. After some experimentation, they started using pulsejets. Those things have little to no moving parts, ar... (more)	—	over 5 years ago
Question	—	Air bladders in bat-like skin wings for better lift? Answers to this question note that human (and by extension mammal) wings would use naked skin instead of feathers, as we see on bats. However, with feathers, birds can have wings with shaped more like those of an aircraft (often with bell-shaped spanload, it seems), which is more efficient than a fla... (more)	—	over 5 years ago
Question	—	Atmosphere of a terraformed 10 km planetoid with Earth gravity Bernal spheres and other O'Neill cylinders are complicated, maintenance-high and fragile beasts. Someone started to make micro-black-holes and put them in asteroids, in order to have 1 to 10+km rock spheres with 1g of surface gravity, and started terraforming those. The micro-black-hole is in a stat... (more)	—	over 5 years ago
Question	—	Submarine propulsion using evaporation In a post-post-apocalyptic world with adequately schizophrenic tech, a tinkerer decides to build a submarine engine around a lump of radium, or some other reliable source of heat. But instead of using some complicated setup to drive a propeller, the engine simply evaporate water in a chamber, then us... (more)	—	over 5 years ago
Question	—	What is the earliest time a pulsejet could be built? Let's assume that some wealthy characters somehow find the plans for a valveless pulsejet. How is not important. Maybe there was a time travel incident, or some Atlantean book was unearthed, or someone had an intuitive leap after accidentally making a jam-jar valveless pulsejet (before it turned into... (more)	—	almost 6 years ago