3 ms·

> Why 0.5G and not 1G though Then the ring would either have to be larger or faster. Both are harder to build.

by SideburnsOfDoom 3y ago

avmich 3y ago
Then the question is, why not smaller. Actually, why 0.5G is chosen as optimal.
- m4rtink 3y ago
  Kind middle between Moon (1/6) and Mars (1/3)?
  - avmich 3y ago
    I agree, and disappointed, that we don't really know how different gravity levels affect human body. We could make experiments of that kind on a space station - free-flying if needed - but chose not to up to now. We'll have to wait for something like a private station to test that. Maybe Moon is quite enough. Maybe Mars is not enough. We don't really know, and we'd better find out.
jrussino 3y ago
> Both are harder to build. Certainly harder for NASA to build in space, but not any harder for this author to build in a computer :-D Good point though: > Regarding the dimensions, I wanted to make the structure as large as possible, while still getting a clear visual sense of the curvature in the interiors. That is how I ended up with the 450-meter radius and 1 RPM spin rate. So it seems like he wanted to put specific constraints on the size/geometry and worked backwards from there.
- jrussino 3y ago
  However, you could get ~1G by going to ~1.4 RMP or increasing the radius to ~900m (or finding some sweet spot in between), which doesn't seem like it would greatly impact the "vibe" he's trying to create.
- SideburnsOfDoom 3y ago
  Right, a part of the film's design was "It should curve enough to look cool". At first I found myself questioning the speed of the rotation, it seemed faster than claimed - 1rpm is not a lot? Then I did the math: A quarter turn is a right angle, floor becomes wall. A quarter minute is every 15 seconds. That's about what's happening in the video. And it's quite disconcerting to watch continuously. I would not want to see faster rotation. So the video is chosen for speed of motion and size of ring, and how they look. 1 G would either be faster motion or less curve, and it seems that the author didn't want those, for valid aesthetic reasons.
dredmorbius 3y ago
NB: A centrifugal artificial-gravity environment need not be a ring. It could be a tethered object spinning around a centre of mass, consisting either of two opposed habitable pods or a single pod and a counterweight. A sufficiently large pod would have an arc-of-circle structure, and multiple independent pods might be arranged in a spoke-like pattern. Given tensile strengths of various cables, this should be generally attainable. Dynamic effects within a tensile-cable structure could however be problematic: shimmies, twists, or other movements, particularly if they are somehow amplified with time.
m4rtink 3y ago
Stronger/heavier materials needed for higher G, right ? All that added inertia could also make maneuvers & burns harder.

> Why 0.5G and not 1G though Then the ring would either have to be larger or faster. Both are harder to build.

avmich 3y ago

Then the question is, why not smaller. Actually, why 0.5G is chosen as optimal.

m4rtink 3y ago
Kind middle between Moon (1/6) and Mars (1/3)?
- avmich 3y ago
  I agree, and disappointed, that we don't really know how different gravity levels affect human body. We could make experiments of that kind on a space station - free-flying if needed - but chose not to up to now. We'll have to wait for something like a private station to test that. Maybe Moon is quite enough. Maybe Mars is not enough. We don't really know, and we'd better find out.

jrussino 3y ago

> Both are harder to build. Certainly harder for NASA to build in space, but not any harder for this author to build in a computer :-D Good point though: > Regarding the dimensions, I wanted to make the structure as large as possible, while still getting a clear visual sense of the curvature in the interiors. That is how I ended up with the 450-meter radius and 1 RPM spin rate. So it seems like he wanted to put specific constraints on the size/geometry and worked backwards from there.

jrussino 3y ago
However, you could get ~1G by going to ~1.4 RMP or increasing the radius to ~900m (or finding some sweet spot in between), which doesn't seem like it would greatly impact the "vibe" he's trying to create.
SideburnsOfDoom 3y ago
Right, a part of the film's design was "It should curve enough to look cool". At first I found myself questioning the speed of the rotation, it seemed faster than claimed - 1rpm is not a lot? Then I did the math: A quarter turn is a right angle, floor becomes wall. A quarter minute is every 15 seconds. That's about what's happening in the video. And it's quite disconcerting to watch continuously. I would not want to see faster rotation. So the video is chosen for speed of motion and size of ring, and how they look. 1 G would either be faster motion or less curve, and it seems that the author didn't want those, for valid aesthetic reasons.

dredmorbius 3y ago

NB: A centrifugal artificial-gravity environment need not be a ring. It could be a tethered object spinning around a centre of mass, consisting either of two opposed habitable pods or a single pod and a counterweight. A sufficiently large pod would have an arc-of-circle structure, and multiple independent pods might be arranged in a spoke-like pattern. Given tensile strengths of various cables, this should be generally attainable. Dynamic effects within a tensile-cable structure could however be problematic: shimmies, twists, or other movements, particularly if they are somehow amplified with time.

m4rtink 3y ago

Stronger/heavier materials needed for higher G, right ? All that added inertia could also make maneuvers & burns harder.