3 ms·

What about the sci-fi ships that rotate very quickly and use the momentum as a form of false gravity - iirc, the basic physics seems legit (I recall an Einstein

What about the sci-fi ships that rotate very quickly and use the momentum as a form of false gravity - iirc, the basic physics seems legit (I recall an Einstein thought experiment along those lines). Or: use the acceleration/deceleration to create gravity. Are they impractical to build or power?

carapace 7y ago
Are you thinking of an O'Neill colony? https://en.wikipedia.org/wiki/O%27Neill_cylinder https://en.wikipedia.org/wiki/O%27Neill_cylinder > The O'Neill cylinder (also called an O'Neill colony) is a space settlement concept proposed by American physicist Gerard K. O'Neill in his 1976 book "The High Frontier: Human Colonies in Space". O'Neill proposed the colonization of space for the 21st century, using materials extracted from the Moon and later from asteroids. > An O'Neill cylinder would consist of two counter-rotating cylinders. The cylinders would rotate in opposite directions in order to cancel out any gyroscopic effects that would otherwise make it difficult to keep them aimed toward the Sun. Each would be 5 miles (8.0 km) in diameter and 20 miles (32 km) long, connected at each end by a rod via a bearing system. They would rotate so as to provide artificial gravity via centrifugal force on their inner surfaces.
- cstross 7y ago
  O'Neill's colony design is flawed (and needs updating): in particular they had huge glassed-in window areas to admit sunlight (focussed via reflectors) for agriculture: he didn't account for differential heating-induced expansion/shrinkage. On the other hand, he didn't have modern CAD back in the early 1970s. So in principle we can come up with something better. The biggest problem is exposure to cosmic radiation -- L5 is way outside the Van Allen belts and high energy cosmic rays take roughly a metre of water to attenuate, or magnetic fields of 10-20 Tesla strength around the spacecraft. Which is a lot of mass (or a ridiculously strong magnetic field). See also: https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays
  - deleted 7y ago
    [deleted]
  - carapace 7y ago
    Oh hey Charlie Stross! I'm a bit of a fan. - - - - I have a vague idea that a kind of spittle bug foam design made from bubbles of various diameters nested to provide redundancy might work well. https://en.wikipedia.org/wiki/Spittle_bug#Spittlebug_nymphs https://en.wikipedia.org/wiki/Spittle_bug#Spittlebug_nymphs It's could be simple, flexible, easy to construct or modify, and resilient to impacts. I'm not an engineer or scientist though. - - - - A tangent, if I may... I think we need more near-term hard sci-fi set in the future that e.g. Musk's space trucks are about to enable, to get more people excited and involved. I've been trawling through Netflix and cable recently looking for inspiring, even-slightly-realistic sci-fi and it's a barren desert out there. There are a handful of shows that aren't bad, and I've heard good things about "Black Mirror". One the other hand, I watched a clip of "Star Trek: Discovery" the other day and had a minor apoplexy. It's more like a cartoon than the actual cartoon. In contrast, I have a "100 Sci-Fi Movies" DVD set that my sister got me for Christmas one year, and a lot of the older black & white sci-fi movies are practically documentaries for space exploration and colonization. Sure there are silly aliens and such, but the technology and settings are realistic (at least compared to e.g. Star Trek or Star Wars.) I think some concrete visions of what it might actually be like to attempt to build and live on a moonbase or Mars colony would inspire people to want to really do it.
    - TheSpiceIsLife 7y ago
      Have you watched or read The Expanse?

carapace 7y ago

Are you thinking of an O'Neill colony? https://en.wikipedia.org/wiki/O%27Neill_cylinder https://en.wikipedia.org/wiki/O%27Neill_cylinder > The O'Neill cylinder (also called an O'Neill colony) is a space settlement concept proposed by American physicist Gerard K. O'Neill in his 1976 book "The High Frontier: Human Colonies in Space". O'Neill proposed the colonization of space for the 21st century, using materials extracted from the Moon and later from asteroids. > An O'Neill cylinder would consist of two counter-rotating cylinders. The cylinders would rotate in opposite directions in order to cancel out any gyroscopic effects that would otherwise make it difficult to keep them aimed toward the Sun. Each would be 5 miles (8.0 km) in diameter and 20 miles (32 km) long, connected at each end by a rod via a bearing system. They would rotate so as to provide artificial gravity via centrifugal force on their inner surfaces.

cstross 7y ago
O'Neill's colony design is flawed (and needs updating): in particular they had huge glassed-in window areas to admit sunlight (focussed via reflectors) for agriculture: he didn't account for differential heating-induced expansion/shrinkage. On the other hand, he didn't have modern CAD back in the early 1970s. So in principle we can come up with something better. The biggest problem is exposure to cosmic radiation -- L5 is way outside the Van Allen belts and high energy cosmic rays take roughly a metre of water to attenuate, or magnetic fields of 10-20 Tesla strength around the spacecraft. Which is a lot of mass (or a ridiculously strong magnetic field). See also: https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays
- deleted 7y ago
  [deleted]
- carapace 7y ago
  Oh hey Charlie Stross! I'm a bit of a fan. - - - - I have a vague idea that a kind of spittle bug foam design made from bubbles of various diameters nested to provide redundancy might work well. https://en.wikipedia.org/wiki/Spittle_bug#Spittlebug_nymphs https://en.wikipedia.org/wiki/Spittle_bug#Spittlebug_nymphs It's could be simple, flexible, easy to construct or modify, and resilient to impacts. I'm not an engineer or scientist though. - - - - A tangent, if I may... I think we need more near-term hard sci-fi set in the future that e.g. Musk's space trucks are about to enable, to get more people excited and involved. I've been trawling through Netflix and cable recently looking for inspiring, even-slightly-realistic sci-fi and it's a barren desert out there. There are a handful of shows that aren't bad, and I've heard good things about "Black Mirror". One the other hand, I watched a clip of "Star Trek: Discovery" the other day and had a minor apoplexy. It's more like a cartoon than the actual cartoon. In contrast, I have a "100 Sci-Fi Movies" DVD set that my sister got me for Christmas one year, and a lot of the older black & white sci-fi movies are practically documentaries for space exploration and colonization. Sure there are silly aliens and such, but the technology and settings are realistic (at least compared to e.g. Star Trek or Star Wars.) I think some concrete visions of what it might actually be like to attempt to build and live on a moonbase or Mars colony would inspire people to want to really do it.
  - TheSpiceIsLife 7y ago
    Have you watched or read The Expanse?