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Open Knowledge - Notes to myself : seasteading, airsteading, bodyweight exercises

Dec. 30th, 2004

09:33 pm - Notes to myself : seasteading, airsteading, bodyweight exercises

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* The biggest problem with using hydrogen with an airship is the flammability. Could hydrogen be made non-flammable (or non-flammable enough) by making it into a foam? Maybe by using fluorocarbons?

* Could you make a autogyro with giant, inflatable helium filled wings? Perhaps using tensairity principles to make the blades rigid enough? What about a helium filled flying wing? Powered parachute?

* Current designs for seasteads call for monolithic ferrocement construction. However, ferrocement is very heavy, and it would be difficult to build the seastead offshore, then transport it to the ocean. Could a variant of panelized construction be used? Maybe design the pillar as an ocatagon, and use tiled interlocking panels. Could they be made water tight? What about expansion/contraction due to thermal differentials?

* What about using pillowdome technology to build a large rigid hexagonal geodesic sphere? How were the pillowdomes made watertight? How much aluminum/tefzel would be required to build a structure sufficient for carrying a family of 4+4? How would such a structure respond to high winds? How could it be safely tethered? Are "airsteads" practical?

* What about using water ballast for seasteads instead of concrete?

* What about using a photovoltaic fabric to cover the surface of the airship? The electricity generated could be used to form hydrogen, and thus keep the sphere perpetually afloat. What are the current limitations of photovoltaic fabrics?

* Could you make a Tent cot akin to a tri-fold stool?

Body weight exercises:

park bench press - lean against park bench in push up position, push against bench with explosive force
assisted squat - lower yourself on one leg, then up, using the other leg to assist as necessary
frog squat - hunker into squat position, then walk forward in the position
air pushups - alternately push your arms into the air, as if you were walking on your hands
lunge walk - self-explanatory
leap frog - self-explanatory
bear crawl - bend over and place your hands on the ground. Keep your legs fairly straight so that your body forms an inverted v. Walk forward

Comments:

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From:phanatic
Date:December 31st, 2004 03:22 am (UTC)
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The biggest problem with using hydrogen with an airship is the flammability. Could hydrogen be made non-flammable (or non-flammable enough) by making it into a foam? Maybe by using fluorocarbons?

Well, it still wouldn't get you much over just using helium. Heck, using vacuum-filled unobtanium balloons gets you something like 6% more bouyancy than using helium.

Could you make a autogyro with giant, inflatable helium filled wings?

Depends. Do you really mean an autogyro, in which the wing is a rotary one? If so, I can't see that it'd be practical: any material strong enough withstand the wing loading in various dimensions is going to be heavy enough that it's gonna kill any benefit you might see from filling it with a bouyant gas. If you're talking about some kind of hybrid, with a free-wheeling rotary wing paired with a fix wing, I still don't see it being useful. The point of an autogyro is that forward motion spins the rotary wing, generating lift. Big helium-filled fixed wings = much drag = little forward motion = little lift from the rotary wing. I could see a rigid or semi-rigid gas-filled lifting body, but not an autogyro.

What are the current limitations of photovoltaic fabrics?


Shitty efficiency. Keep in mind that commercial hydrogen generation involves steam reformation of hydrocarbons, not electrolysis, which requires a great deal of power.
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From:crasch
Date:December 31st, 2004 03:37 am (UTC)
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As I wrote in the title, these are mostly notes to myself -- I'm not saying any of these ideas are workable.

With respect to hydrogen foam, I'm not trying to get more lift. Helium's scarce and expensive--the U.S. controls most of the known world reserves. Hydrogen is abundant, and can be manufactured onsite. It can also be used as a fuel source, so the same gas used to provide lift could also be used to power an engine for propulsion. The biggest disadvantage to hydrogen is its flammability.

Photovoltaic fabrics may have shitty efficiency, but airships have a lot of surface area.
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From:patrissimo
Date:December 31st, 2004 05:19 pm (UTC)
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What about using water ballast for seasteads instead of concrete?

Umm...water has a ballast capability of precisely zero.

When you are underwater, weight is measured relative to the surrounding water. If you have water, underwater, it weighs nothing! Hence it does no ballasting.
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From:crasch
Date:January 1st, 2005 03:21 am (UTC)
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Thanks!

Hmmm...Water ballast seems to be used for some boats. What do you think their rationale is?
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From:patrissimo
Date:January 1st, 2005 08:03 am (UTC)
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That water is removing airspace, hence reducing flotation. So I guess in some sense it has weight, and can act as ballast. But it cannot significantly lower the center of gravity, like real ballast, because it is the same density as the surrounding water. (ie put water in water, what happens? it neither floats nor sinks - totally neutral).
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From:dandv
Date:December 13th, 2010 07:19 pm (UTC)

Are airsteads practical?

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I just finished writing an essay for my nanotech class on the use of nanotechnology in airsteading inside tensegrity spheres with primary energy production from jet stream turbines.

It seems that the technology may be pretty much there, for the floating sphere part, For the turbines, estimates are 15-20 years away.
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