Stranger On a Train Tensegrity - Wikipedia ?
Am I reading that right? Is it claiming that a structure such as a geodesic sphere with proper Tensegrity can be limitlessly big, in gravity? Don’t the materials still have a finite strength/weight ratio, no matter how well balanced?
There are female nerds, though they are rarer. I’m male, by the way, so I can’t use myself to refute your statement.
Which brings up an interesting point. Clearly there is about 1 g inside the Death Star, at each level, but how is it implemented? Is there a point source, or is there a gravity generator on each floor? If so, how far does it extend? Many of the structural members could be under 1 G anyhow because of this.
I’ve not read anything on the subject by anyone other than Bucky and his disciples, but I think that’s the case. I know that if you build a geodesic structure one mile in diameter, it will float the moment the air inside of it becomes 1 degree warmer than the ambient temperature.
Spheres, domes, and egg shapes have some pretty unique properties That’s one of the reasons why you see so much of them in nature (After all, when was the lat time you saw a square tree?).
Never look to movies or television for an interesting examination in the complications of artificial gravity. Even prose science fiction tends to gloss over what would have to be a fairly difficult process (each “solution” introduces its own set of engineering complications and questions of “Well then why don’t they do this?”).
In ROTJ it appeared to be a hollow shell with a reactor in the middle. Keep in mind that shell is still several miles thick.
The answer to the OPs question is that it is impossible to answer. We simply don’t have the technology to create a space station in orbit that’s 120 km across.
Yeah, but you’re forgetting that Star Wars took place “A long time ago in a galaxy far, far away.” A long time ago, as in before the era of those old-timey ads that used to appear on the tables at Wendy’s in which everything was cheaper than dirt because there was no inflation.
My best guess: 83 bucks for the whole schmear.
Or credits.
Whatever.
Essentially yes, because the strength/weight ratio is evenly distributed over the whole structure. So I think essentially the ratio is always the same. Building such a structure on Earth would be problematic as you would have gravity to contend with. I’ve built Geodesic domes and the larger domes require a crane, but the structure is quite sound when put together fully. The largest I’ve seen are 60 foot domes.
Well it was built using a command economy. Almost the entire wookie race was enslaved prior to “A New Hope”.
Are you saying that gravity merely complicates the construction process, until the dome is completely assembled and all stresses evened out? I still can’t bend my mind around what sounds like a claim that there’s NO limit to how big a tensegrity structure could support itself in gravity. At some finite limit steel flows under enough pressure.
So, a Pykrete Star, then?
But in a geodesic structure the stresses are distributed evenly across the structure, and because the perimeter grows larger as you go lower down the bearing line load grows smaller as the size of the structure increases. Build it large enough and the stresses are actually trivial, only slightly more than the member needs to support its own weight (although bending stresses from flexure may still be significant in a gravity field). Contrast this with a normal rectangular frame building where the bearing area increases only proportionally to an increase in floor space, and not at all as it increases in height. Large dome structures are somewhat more complicated to build because until the structure is complete (or nearly so) the tensile reinforcement doesn’t exist, but you can build really massive structures without external support by constructing an interim framework.
In essence, yes, albeit one reinforced by long directional fiber substrate rather than short fiber composite matrix. This is important to give it a tensile strength that Pykrete doesn’t possess, especially if it is to be spun to simulate gravity (again assuming something like near-term technology rather than advanced black box space opera tech).
Stranger
The Star Wars universe, as well as most other sci-fi universes, seem to have amazingly cheap and reliable artificial gravity. Whether the generators are on very floor, or it’s part of some shipwide gravity/anti-intertia field, is hard to say. Note, however, that even dinky little ships like the Millennium Falcon have perfectly functioning artificial gravity on more than one deck (gravity still works when Han Solo is under the main floor trying to fix the hyperdrive in “The Empire Strikes Back.”) Similar effects are to be found in Star Trek, or even in less advanced-looking universes; in “Battlestar Galactica,” where they don’t even have beam weapons, artificial gravity is not only easily had, but it never breaks down, even when the ship has lost many other key systems. Loss of artificial gravity has bene used to effect a few times in “Star Trek” but it’s pretty clearly indicated that this is considered a catastrophic event and would happen only if the ship is utterly crippled, and sometimes not even then; many ships that are otherwise on the brink of falling apart still have their artificial gravity (cf. Wrath of Khan, Star Trek IV, and others.) Artificial gravity seems to be the ship’s #1 systemic priority.
It also seems trivially easy for ships to overcome planetary gravity; the Falcon, and other spacecraft like an X-Wing fighter, are seen leaving large planets in a matter of moments at various points in Star Wars. In Star Trek, the original Enterprise was actually built on Earth. Civilian ships seem to have no problem leaving a planet’s surface in “Battlestar Galactica.”
**Gravity has apparently been more or less defeated in our sci-fi universes. ** If that’s true, getting the material off a planet is not an issue.
RickJay As I said, they show a giant railgun delivering material from a planet in Force Unleashed.
Lumpy Stranger nailed it. The perimeter of the base grows. If the midline of the diameter is above the ground then your point is probably valid if it is subject to external gravity. But a half sphere as opposed to a 3/5 or 3/4 sphere can pretty much support any size. Basically the ratio of spars in the bottom layer expands at such a great rate that you are not supporting a significantly larger amount of spars above the first level.
A good example would be the human body which is held together by a tensegrity structure called ‘Fascia’ that interweaves our entire body, just under our skin and around every muscle and organ.
More logical* to imagine that artificial gravity is a passive system (I dunno, like a gravity-version of rare earth magnets or something?). Although, as you point out, Star Trek mucks that up by having artificial gravity fail on occasion.
- Wait, did I really just say “logical” with regard to Star Wars or Star Trek? :dubious:
I’m a bit disappointed that no one got this reference. It’s from Family Guy:
(There are no copyright issues with this video on YouTube, since it’s posted by hulu.com)
We got it, along with your user name, it just wasn’t that funny.
Okay.
Let’s call it one multiplujillion, nine obsquatumatillion, six hundred twenty-three dollars and sixty-two cents and call it a day.