Artificial gravity through air flow

[scintor]

I was thinking randomly today and I had a strange thought. one of the big problems with space is gravity, or lack thereof. The two Sci-Fi standards for solving this delimma are rotation and the magic gravity generator.
I had a srtay thought that you could use the ventelation system to simulate gravity through air flow. You would have to have a pourous ceiling and floor that would allow a constant flow of air to push everything away from the celing and pull it toward the floor. It would not be the same as gravity (for one thing it wouldn't do anything for your sense of balance) and of course all that air could get pretty noisy, but the idea seems workable for at least some gravity like conditions in small areas.
What do you think?

Scincerely,

[e-mail]

[torainfor]

I can see people wearing wide, shallow hats, since there's not a lot of area on the human body to push down on from straight above. But then you'd have your entire "weight" pushing down on your head and neck. Maybe better to have wide, shallow skirts held up by suspenders and stabilized by bungee cords.

I think it's time for me to go to bed, now.

[Vaporwolf]

The airflow idea is interesting, but seems impractical due to speed of wind needed and the probability of the porrus floor and ceiling getting clogged.

I think the airflow idea would work for "lift tubes".

I do think that it would be an incredibly fun concept for a comedic sci-fi story where people have to wear funny looking "gravity suits" so the air flow keeps them "grounded".

[Therin]

Well, maybe you could have a far-fetched system in which the air is sucked into the center of a spherical craft and then piped to the outer parts, maybe creating a simulation of mass in the center. Yeah, it probably wouldn't work. But that's why we have science FICTION.

In my own random thoughts on artificial gravity, I've considered having magnets in boots that keep your feet on the floor. Again, it wouldn't help with balance, but at least it would provide some sort of counter to muscle atrophy (probably the primary purpose for artificial gravity in the first place).

[Spokane Flyboy]

I've always thought of artificial gravity as a more a convenience since you wouldn't have to spend as much time grasping how to move about.

[scintor]

I'm one of those Hard Sci-Fi wierdos. I'm not looking for something that makes a good plot element as much as something that would create a reasonable zero-g working and living environment with actual technology. If you don't care if your technology is realistic or magical, then this idea won't matter to you.
The problems with zero-g go far beyond muscle atrophy. Without a down, people get disoriented, which causes nasuea and vomiting (even for vetran astronauts, this is a common problem.) Huge numbers of eveyday assumptions must be rethought and re-engineered. Most important of all, it that we are designed by our Creator to live in gravity and we just plain don't work right without it.
Rotation is a great form of artificial gravity, within its limits. It works well for stationary objects, as long as they are not too small or too large. Too small and you have constant dizziness that's worse that zero-g. Too large and the strain on the structure becomes too great for known building materials. There is also the problem that in such structures, "gravity" varies by elevation, which sets all sorts of limits on what you can do. Rotation doesn't work for small ships or ships that need to maneuver (due to torq.)
The air flow technology would be useful in some situations, but would also have it's own limits. The advantages are: You would have an up and down for orientation and convienience. You would also have easy adjustability built in (just turn up or down the fans,) and different parts of the ship can have diferent levels of "gravity" for different purposes.
The most obvious difference is that "weight" would be dependant on cross-section and not mass. Areas of wind shadow would become weightless (which would lead to some wierd effects like dust bunnies forming in a mid-air vortex under a chair or table.) Most areas would have very light "gravity" (maybe 1/10th) which would be supplimented by things like magnetic soles and pads and velcro. Workout rooms would be the only ones that would use the gale-force winds that would be needed to equal full gravity, and that would help with bone degeneration.
It wouldn't be a desirable environment necessarily, just workable.

Scincerely,

[e-mail]

[torainfor]

Ben Bova uses rotation on smaller craft by connect two of them (or one craft and a counterweight) with bucky cables. They spin around a combined center of gravity somewhere in the middle. I don't exactly know how he manages forward thrust, though.

Physical options, although crude, must be considered, but you can't exact an external force on a body and have it anything close to natural. A belt or harness connected with bungees would only pull down on certain body parts (like shoulders or hips) and would irritate the skin, besides.

What about genetic manipulation that causes the bones to grow with some substance that has an attraction to another substance in the floor? It would be like magnetic, but I'm hesitant to suggest pure magnetism since that could wreak havoc on navigation equipment, not to mention our own physiology. The pull of gravity would be more based on bone structure than mass, but it's better than wearing a skirt that looks like a dog cone. All you have to do is discover (or create) an inert substance that has its own non-harmful attractive field, and can be shielded on one or more sides so your ship can have more than one level.

[scintor]

I am working out some ideas for later books in the series that I'm working on (hopfully it gets that far.) Counterweight rotation is great as long as you are going in a straight line at a constant speed. I am thinking about battle capable warships. Rotational ships would be far too fragile or cumbersome for battle, and would be extreemly hard to maneuver as well. Ships that were not rotational would have a big advantage.

The bungie systen that you describe is what they are currently using on the International Space Station. A romm with 60MPH winds pushing you toward the floor would be much more effective in giving you the type of workout that stops muscle and bone loss.

The funky clothing would probably not be used as you can get enough resistance to be useful without it, but you never know what someone would try.

Genetic engineering or surgical implants would be a bit extreem. just dealing with the naseua and disorientation would be easier.

Scincerely,

[e-mail]

[Spokane Flyboy]

I've always thought of developing some hi-tech material that would be lined in the underside of a ship, possibly made of something similar to the dense matter of neutron stars, but a thin sheet made with nano technology. Though I likely have a wrong conception of what exactly creates gravity.

[torainfor]

I have thought of that, too, but I'm worried about levels in the space ship. If the CG is only a few feet from the floor of the bottom level, the difference in gravity pull five stories up would be substantial, I think. On planets or on rotating stations, the gravity force is focused on a single point "below" you. If the gravity source on a ship were spread throughout the floor, how would that differ? The floor five feet away and twenty feet away would still be pulling on you.

I want an aimable gravity field. The source of gravity would actually be in the nose. Floors would be smaller (easier to use an elevator than walk all that distance, anyway), maybe even curved like a section of a sphere. But somehow the gravity force would be consistent throughout the levels. In front of the ship, the gravity field would be focused into a thin beam. It would find a greater mass out there, somewhere, and pull the ship forward.

Sounds more fantasy than sci-fi, yeah?

[Spokane Flyboy]

I imagine it would depend on the draw of the first floor. I imagine anything that could pull at 9.8/m/s/s would not be mitigated within 5 floors. The only problems I could see with this from a realism standpoint is that it might greatly increase the mass of the ship. It also might happen to have a gravitational pull that had as far a reach as Earth's, which would also be problematic. Though, I'm not well versed in this part of science, so I don't know what all the caveats would be.

[rwley]

Okay, I know nothing about gravity and I'm not science savvy at all, but how about this just for grins; each floor surface would have hundreds of tiny little 'vacuum cleaners' that would simply suck you to the floor. Create a strong enough suction that it would force you to use your muscles to move, but not so much that it would be overly cumbersom. You still have up and down because you have floor and ceiling, and you have resistance so you don't have to deal with degeneration and atrophy.

Just a thought.

Robi

[torainfor]

Flyboy, I've been avoiding it for months, but you made me do it. Bear in mind, I haven't a math class since 1991, so be gentle.

Earth mass: 5.98E+24 kg
Gravitational constant: 6.67E-11 m3/s2-kg
Gravitational acceleration at sea level: 9.8 m/s2
Arbitrary distance from first floor to gravitational source in space ship: 1 m
Crunch through slightly atrophied brain (F=ma=GMm/r2)
Required mass to maintain 9.8 m/s2 at distance of 1 m: 1.47E+11 kg
Arbitrary distance from upper floor to gravitational source in space ship: 5 m
Force of gravitational source on upper floor: 27.4 m-kg/s2
Arbitrary weight of astronaut: 70 kg
Acceleration on astronaut on upper floor: 0.392 m/s2

All that to say, if a floor one meter above a gravitational source is to have the same gravitational acceleration as Earth at sea level, 9.8 m/s2, a floor four meters higher will have an acceleration of only 0.392 m/s2.

I think.

[torainfor]

rwley,

I was going to go into a long dissertation about the difference between gravity and your idea, but my mind has been waylaid by two thoughts: it would be quite breezy, and you'd have to wear a tight belt.

[scintor]

Rwley,
you're thinking much like I am, only I would also have jets of air coming out of the celing. and magnetic boots to stick you to the floor as well.

torainfor,
The breeze factor is one of the major limitations of this idea. I probably should edit my original post to include the idea of both the push from the top and the pull from the bottom. I'm not thinking of full gravity replacement in most situations, just enough push-pull to keep you connected to the floor.