5 ms·
A friend of mine was doing a Masters in Zoology a few years ago, and I briefly discussed the idea of generation ships with her. She explained to me that a foet
by dvtv75 10y ago
A friend of mine was doing a Masters in Zoology a few years ago, and I briefly discussed the idea of generation ships with her. She explained to me that a foetus can't properly develop in microgravity, and they abort in the early stages. (I can't really remember because it's going back 12-13 years now.)
Accelerating such a ship at close to 1G for half the journey, then flipping it over and decelerating at the same for the other half of the journey would approximate Earth gravity for the occupants. Since acceleration acts by pushing against you, rather than acting against your entire body as gravity does, I'm unsure as to whether it would be an adequate substitute for gravity.
Perhaps someone here knows.
- douche 10y agoThe other option (from the science fiction, anyway) would be to revolve part of the spacecraft enough to generate sufficient centripetal force to approximate gravity. It's become almost a trope since 2001, but I'd imagine there are some significant engineering challenges to actually implement such a thing. How do you keep the drum rotating, without spinning the rest of the craft? How do you engineer bearings that can handle the force, while at the same time dealing with vacuum and extremes of temperature? There's a lot of moving parts, and moving parts wear, seize, and can fail catastrophically...
- jessaustin 10y agoIf the bearings prove difficult, just rotate the whole thing.
- unlikelymordant 10y agoYou can just spin the rest of the craft as well. No moving parts required.
- dredmorbius 10y agoThat increases mass and engineering considerations. Designing a satellite or space probe is (structurally) pretty simple: you need a central truss or platform which is going to be subjected to very little stress or torque. Pressurised compartments up the complexity a lot. Leaks are bad. Big, fast leaks are really bad. Even with out gravity, thermal gradients (sunlit side, dark side) present significant stress. Pressurised compartments under constant 1g strain are even more complex. You've got stresses and strains, mass, things get dropped and bumped inside, etc. Mass costs money. About $1k to $40k per kg in LEO, though the lower end of that's becoming more viable. Elon Musk and others would like to get down to $200 kg, though I find that unlikely.
- rntz 10y agoAcceleration and gravity are entirely interchangeable. The feeling you get due to gravity is also because of something "pushing against you" - namely, the ground. If you didn't have the ground to push against, nor air to drag against you, you'd be in free fall, which is the same as being in zero gravity.
- dghf 10y ago> Since acceleration acts by pushing against you, rather than acting against your entire body as gravity does, I'm unsure as to whether it would be an adequate substitute for gravity. I'm far from an expert, but I thought it was a basic tenet of relativity that, without external information, there is no way of telling whether your spaceship is accelerating at 1G or standing on the Earth's surface.
- andrewflnr 10y agoI'm pretty sure steady 1G acceleration brings the subjective travel time within a lifetime for a lot of journeys. I haven't done the math myself, though, just heard it from others. Of course, the technology to apply such acceleration to any reasonable-sized ship is rather fanciful at this stage.
- BurningFrog 10y ago> She explained to me that a foetus can't properly develop in microgravity How on (off?) earth can anyone know that?
- dredmorbius 10y agoPresumably animal models. Fish, frogs, mice, etc. https://scholar.google.com/scholar?q=fetus%20development%20in%20microgravity&btnG=Search&as_sdt=800000000001&as_sdtp=on https://scholar.google.com/scholar?q=fetus%20development%20i...