Gravity Balloons

[stevebowers]

This interesting article has come via SciFi ideas
http://www.scifiideas.com/sfi/technology...oid-cores/
note that we have 'gravity balloons' of a sort in the scenario already, as that is what Ederworlds are.

But this writer (who remains anonymous btw) has considered the question in great detail, taking in shellworlds and asteroid colonies as well, on his blog
(which is here)
http://gravitationalballoon.blogspot.co.uk/

Many interesting ideas are addressed there, including how to make a version of Karl Shroeder's Virga megastructure from the resources in our solar system. I have some questions to put to this guy, which I might do in due course (including the best way to make a worldhouse roof so it doesn't rip itself apart within seconds).

His ideas about creating gravity balloons from various types of asteroid, each filled with air and rotating city-states, are intriguing, and we could certainly get some inspiration from them.

[stevebowers]

Interestingly enough, the chap who writes this blog has recently analysed the OA Ederworld concept- he says it is necessarily the result of a very advanced technological culture.
http://gravitationalballoon.blogspot.co....avity.html
Some very interesting data there, and I'll attempt to contact him to see if we can use it.

I 'd really like to use some of his other ideas as well - they appear to be very large, roomy megastructures that could be built with modosophont tech.

[ai_vin]

Ah, good to see I wasn't completely off my rock when I wrote the Eders piece.

[ai_vin]

BTW, I wonder who ratted us out to this guy?

[stevebowers]

That would be Mark Ball at Scifi ideas, who posted a link to our site back to the Gravity Balloons guy.

[AlanSE]

I had overlooked Orion's Arm. Although I knew of it from the self-gravitating ring concept, I never found any direct precedents for what I wrote about in the blog, but the Ederworld page really did have that. It's a derivative concept of a gravity balloon. However, the originator of that idea calls them Bubbleworlds, and that threw me off. I'm still interested in finding information on that Bubbleworld concept, but it's a real moving target. Going by the article, it seems that any gravity balloon might be called an Ederworld. I don't know what the scope of that word is. I like to call them gravity balloons, because there's no ambiguity about that definition. A gravity balloon might not be a human habitat, it's just... a balloon-ish thing. I would particularly like to know if Eder's Bubbleworld concept had entertained the idea of using asteroids, and anything else about it.

Using flow dividers to get artificial gravity to work is the real central concept of what I've written. Maybe we could put up an article about this on Orion's Arm? The gravity balloon concept itself has been around for a while, but the flow dividers are (IMHO) what makes it potentially useful in a "The High Frontier" kind of way. The tech level doesn't even come close to other concepts that do the same thing unless you're at a really small scale, like Kalpana One, which is for 3,000. Right around that point, you really have to start to wonder if the trip and the isolation might be worth it to save such an insane amount of industrial resources.

And Blogger just outright tells you traffic sources, so you have no one to blame but yourself.

[JohnnyYesterday]

A few years ago when I began thinking about my own world (which is a gravity balloon of a scale not much below the Jeans radius of a molecular cloud), I hit upon the idea of the spin-gravity habs being contained inside nearly-form-fitting vacuum chambers.

[stevebowers]

Using flow dividers to get artificial gravity to work is the real central concept of what I've written. Maybe we could put up an article about this on Orion's Arm? The gravity balloon concept itself has been around for a while, but the flow dividers are (IMHO) what makes it potentially useful in a "The High Frontier" kind of way. The tech level doesn't even come close to other concepts that do the same thing unless you're at a really small scale, like Kalpana One, which is for 3,000. Right around that point, you really have to start to wonder if the trip and the isolation might be worth it to save such an insane amount of industrial resources.

This sounds like an excellent idea. If moderately sized gravity balloons can be created from asteroid material, then these might be built in some or many colony systems as a way of housing a substantial population.

[Cray]

I like the self-gravitating approach to resisting 1-bar of pressure.

Instead of the many layers of flow dividers, you could just use a single-layered, closed aluminum (or plexiglas, or whatever) shell. The total air frictional losses between the solid shell and the internal spinning habitat should be about the same as the many-layered flow divider, and a single shell simplifies a lot of design issues (dissipating frictional heat, maintenance access, etc.) Poke a few holes in both shells and you've got free ventilation, delivered by the same electric motors that maintain the internal shell's spin against drag.

As for walking out of the spinning habitats, I'm not sure how practical that approach would be. For habitats that keep their angular rotation down to stomach-friendly rotation rates (1rpm or less for most people; 1-3rpm with adaptation), you're looking at ~2km-diameter habitats for 1G. You'd need mechanical transport - elevators or some parallel "subway car" system" - to debark. It wouldn't be hard to move between adjacent habitats, but it'd be a move of more than a few kilometers.

[stevebowers]

I have told Alan that we will do a write-up on these objects, but real-life time constrains keep cropping up. If anyone wants to make a start they are welcome. Gravity Balloons might be a relatively widespread form of megastructure, combining rotating habitats with vast volumes of habitable microgravity space.