Alternatives To Rotating Sections For Artificial Gravity?

[Knight Templar]

Of course in Star Trek, all ships have artificial gravity generators that do the job.

Babylon-5 and various other shows and movies have shown ships with sections that rotate to simulate gravity.

What are some alternative technologies that a spacecraft NOT ACCELERATING could possibly use to simulate say .1 to .2 Gs for the crew?

In the brief series "Defying Gravity" it was explained that the crew had metal woven into their uniforms and that magnets in the ship simulated the pull of gravity and that tiny "nanobot dust" in their hair did the same.

Is this really possible?

 

[sojourner]

No. The only really viable methods are centripetal force (i.e. rotating sections) and constant acceleration in one direction at 1g of thrust. Everything else is - appropriately for this board - science fiction.

 

[Christopher]

In the brief series "Defying Gravity" it was explained that the crew had metal woven into their uniforms and that magnets in the ship simulated the pull of gravity and that tiny "nanobot dust" in their hair did the same.

Is this really possible?

No, that was just silly. For one thing, why not just cut their hair short? And it would be pretty dangerous to have metallic dust floating around all over the ship (no way would it stay in the hair, especially if it's a hairspray as they claimed) and getting into sensitive electronics, not to mention into people's lungs.

Not to mention that having magnetism pulling on your clothes wouldn't really help with the effect of microgravity on circulation, digestion, etc., and it would make it problematical to use any larger metal objects, which would also be under the influence of the magnetic field. And the field might interfere with electronics too.

Other than rotation or thrust, the only other way to have shipboard gravity under currently known physics would be to build the ship around a hyperdense compressed mass. Robert L. Forward wrote about this, suggesting that a chunk of degenerate matter could be created by shaped nuclear explosions, then encased in a shell of synthetic diamond before it re-expanded (though it would do that pretty much instantly, so that would be very hard to do). It would be dense enough to generate a significant gravitational pull at close range. The problem is that it would make the ship so massive that it would be pretty hard to move it around, or to stop or change course once it was in motion.

 

[Edit_XYZ]

In the brief series "Defying Gravity" it was explained that the crew had metal woven into their uniforms and that magnets in the ship simulated the pull of gravity and that tiny "nanobot dust" in their hair did the same.

Is this really possible?

No, that was just silly. For one thing, why not just cut their hair short? And it would be pretty dangerous to have metallic dust floating around all over the ship (no way would it stay in the hair, especially if it's a hairspray as they claimed) and getting into sensitive electronics, not to mention into people's lungs.

Not to mention that having magnetism pulling on your clothes wouldn't really help with the effect of microgravity on circulation, digestion, etc., and it would make it problematical to use any larger metal objects, which would also be under the influence of the magnetic field. And the field might interfere with electronics too.

You've just shown it can have secondary effects.
It's a LONG way from here to 'it's silly' AKA not possible as per physics.
Your conclusion FAR exceeds your argument.


PS - Among the secondary effects, the metallic dust one is the only one worth considering.
And this objection is largely eliminated if one replaces this metallic dust with another non-toxic, non-conductive 'dust'.

As for the rest:
It wouldn't really help with the effect of microgravity on circulation, digestion?
It would help - as in, completely eliminate - the effect of microgravity on bones and muscles, which astronauts spend hours a day (as in, a large fraction of their time) trying to minimize by physical exercise.

Metallic objects would actually have simulated weight, as on Earth, due to the magnetic field? Good.
BTW, this would prevent the magnetic dust from remaining in the air by pulling it onto the floor.

Electronics can easily enough be shielded from magnetic fields.

 

[Knight Templar]

What about IIRC it is called laminar air flow?

Constant, steady flow of air from the "ceiling" of your habitation and work areas that flows smoothly and steadily to into the floor which is riddled with countless tiny air ducts on every possible exposed surface?

Don't know if you could ever do it enough to simulate the effects of gravity though.

For that matter, could you design uniforms with some kind of material that resisted every bodily movement and at least regarding skeletal muscles simulated gravity?

 

[Asbo Zaprudder]

In the movie 2001: A Space Odyssey, something akin to velcro strips were shown being used to temporarily stick people's feet to the floor in the Orion and Aries lunar shuttle sequences. I don't know that this method has ever been tried for real but I suspect that it would look much more comically ungainly than what was depicted in the film. Of course, it wouldn't mitigate against the biological effects of zero-G environments. Constant linear acceleration rather than rotational acceleration would be my preferred solution (as used in several literary SF works) but that would require some major fundamental advance in propulsion technology.

 

[Knight Templar]

I suppose if you have fusion power at your disposal that constant acceleration for a minimum of .1 or .2 G might be reasonable.

IIRC, you need at least one tenth of a G to have some mitigating effects on the negative consequences of micro gravity.

 

[Christopher]

What about IIRC it is called laminar air flow?

Constant, steady flow of air from the "ceiling" of your habitation and work areas that flows smoothly and steadily to into the floor which is riddled with countless tiny air ducts on every possible exposed surface?

Don't know if you could ever do it enough to simulate the effects of gravity though.

I've had that idea myself as a way to ensure that loose dust, hairs, crumbs, water droplets, etc. get pushed to the "floor" rather than floating around and getting into equipment, lungs, etc. But it wouldn't create any sensation of weight.

For that matter, could you design uniforms with some kind of material that resisted every bodily movement and at least regarding skeletal muscles simulated gravity?

Certainly, to an extent. That could help keep the bones and muscles stimulated so they wouldn't atrophy as much. (There's also been research showing that cats purr at a frequency that stimulates tissue healing, which might be why they do it; so if the garments were built to vibrate at purr frequencies, those might also help fight atrophy.) But again, it wouldn't have the full range of benefits of actual acceleration.

Short of magic artificial gravity, thrust and rotation are always going to be your best options. Gravity is a uniform acceleration on the entire body, inside and out, and both thrust and rotation induce a uniform acceleration in much the same way (pushing the floor up against you rather than pulling you down against it, but it's equivalent by Newton's Third Law), so it's pretty much the real thing, with the same effect on the body (discounting the additional effects of rotation such as the Coriolis force and differential accelerations over the length of the body, but those can be minimized by making the radius of the rotating section large enough). So that's going to be a better option than any halfway solution like airflow or smart clothing.

 

[Redfern]

There's also been research showing that cats purr at a frequency that stimulates tissue healing...

Now I have this absurd mental image of McCoy's recovery ward staffed by Caitian nurses who, in addition to standard nursing duties, cuddle in bed with the patients, softly purring for hours on end, helping to promote tissue regeneration.

Ensign: "Doc'? I 'm not doing too well."

McCoy: "You must be in a poor way, son. This is the 5th time this month you've come down with something!"



Sincerely,

Bill

 

[Christopher]

Sounds good to me...

 

[Crazy Eddie]

You could just have your astronauts take a Fosomax treatment for and have them wear mechanically loaded clothing for the duration of the mission. Then you can keep them in zero gravity (and include all the space-saving benefits) without having to worry about the health effects.

 

[Trekker4747]

In the movie 2001: A Space Odyssey, something akin to velcro strips were shown being used to temporarily stick people's feet to the floor in the Orion and Aries lunar shuttle sequences. I don't know that this method has ever been tried for real but I suspect that it would look much more comically ungainly than what was depicted in the film.

NASA has been using Velcro to secure equipment and astronauts inside of space vehicles since the days of Apollo. Much in the same way here, strips of it on the floor of the Lunar Module and the feet of the LM pilots were used to secure them during maneuvers in flight, as well as equipment and other items that can become loose during flight.

Keep in mind not all Velcro is the weak-ass stuff used to hold kids shoes closed, the stuff NASA uses is likely to be much, much stronger. There's Velcro out there with 100lb/sq.in. strength.

 

[sojourner]

In zero G you actually wouldn't want velcro to be very strong to simulate walking/standing. Too strong and you would have trouble over compensating for "ripping" yourself from the surface with each step.

 

[Christopher]

The conceit of using velcro or magnetic boots to "simulate" walking only makes sense in a TV or movie production filmed on Earth and pretending to be set in microgravity. If you were actually in microgravity, it would be a very inefficient and unnecessary way to get around. It wouldn't actually be like walking, because there wouldn't be the same forces at play, so the dynamics of the motion would be very different (an approximation might be if you had a wheeled platform you could lie down on and tried "walking" with your feet against the wall). And it would be needlessly slow and restrictive. It'd be much easier and more natural just to pull yourself along with your hands, then coast once you've built up speed. Which is how astronauts in space actually do prefer to move around, and why they don't actually wear velcro boots. Simulating walking in microgravity would be as pointless and silly as simulating swimming on dry land.

 

[sojourner]

^Oh I agree. Velcro might be useful for "station keeping" so to speak, but not for locomotion.

 

[publiusr]

Speaking of rotating rings
http://www.universetoday.com/95099/...build-a-real-starship-enterprise-in-20-years/

 

[sojourner]

^Yeah, that guy posted a thread in gen trek. What a really stupid and unworkable idea.

 

[Christopher]

Actually he may have a point that the technology is attainable. Of course he's not proposing something that would actually function like the Enterprise, but something that could exist on a similar scale using current or near-future technology and be actually functional as a space habitat/spacecraft. I assume making it look like the Enterprise is just to generate interest and evoke the symbolism of the ship.

 

[sojourner]

Which is where the problems come in. It won't work if you make it look like the Enterprise. The off center axis of the gravity ring alone will cause the thing to tumble. I can't imagine what would happen when you fire up the engines.

 

[Christopher]

The off center axis of the gravity ring alone will cause the thing to tumble.

Put in a counterrotating flywheel of equal mass. Or build two counterrotating habitat rings.