Using electromagnitism to supply lift for a heavier-than-air airship

[Heartofthewolf]

Hello all, I am an aspiring hard science-fiction writer, and I am looking for a place where I can get some expert advice as to the scientific plausibility of several ideas. I hope that it's okay to ask these sorts of questions here.

 

First off, I have a story idea that's been bouncing around in my head now for a while; heavier-than-air airships. Namely, the sort that are large and very heavy, with thick metal plates for armor, crews of several hundred, and large spaces for very heavy cargo. I want to avoid the usual trope of anti-gravity, and so i was thinking about using electromagnetism. I'm setting this story on another planet, one that has a unique mineral that is heavily magnetic. So magnetic, in fact, that in concentration it reacts with the magnetic field of the planet and levitates off the ground. If the ship were built with several bands of this material running along its length, I imagine it could enable a several thousand ton airship to fly about. My questions are this:

 

1. Is this scientifically plausible?

2. If so, could it be plausible to vary the altitude of the ship by inducing varying amounts of electric charge into the material?

3. Could this effect be somehow manipulated to provide propulsion and maneuvering for such a vessel?

[imatfaal]

I think the airship would flip and get fatally attracted to the ground - it is impossible to use simple magnets for stable levitation, its always unstable in at least one direction - you could look up Earnshaw's law and ways around it (stabilisers, unusual magnets, the levitron etc.)

[derek w]

There are maglev trains in Japan and China.But they only levitate by a small distance of the track.

[Enthalpy]

A mineral much more magnetic than we have isn't expected (at least from me...) because iron, neodymium magnets... show a significant fraction of the strength electrons can produce.

[Ndi]

1. Is this scientifically plausible?

2. If so, could it be plausible to vary the altitude of the ship by inducing varying amounts of electric charge into the material?

3. Could this effect be somehow manipulated to provide propulsion and maneuvering for such a vessel?

 

1. On another planet in sci-fi, yes, BUT: You commit to new laws of physics, all materials affected by the field would behave very differently. And that's a lot of materials. Water included. Water is in organisms. Very complicated. A field that powerful will likely make people hover (more likely, slam into the ground).

2. Yes, BUT: Magnetic forces vary a LOT with distance. For every meter in length you'll probably have to add another zero to the power and, frankly, by 5 meters you'll probably be better off just putting an engine on it.

3. Not likely. Assuming a model where these rocks are part of the outer crust (otherwise it'd just be silly zeroes everywhere), then the crust would need to be smooth and aligned for this to work (otherwise you'd wobble around like a car on a bad road). If it's smooth then you will be aligned to it or unstable (depending on field alignment) unless aided by aerodynamics.

 

You could lose altitude with wings attached, and thus move forward, then regain it. The power requirements, however, would be enormous, as lost altitude does not put any more gas in your tank - you'd have to bench-press the ship.

 

So, no, basically by the time you put all this together you kill so much of physics you'll have trouble explaining how plants don't jump from the ground.

 

If you want to work with magnetism, go small distances, it will make it workable.

If you want giant ships, I suggest you go with magic density atmosphere. A reasonable engine that takes advantage of this soup will be able to hover relatively easily, and copy the aerodynamics from blimps and subs.

If you just want cool-sounding sci-fi stuff, make the atmosphere magnetic-responsive. You could use a powerful field inside a static engine to compress the atmosphere to a tiny fraction of its size, lure it into another, lower part of the engine, and let it rip. It would look like a static fan, and would make a killer cover - the engines would look like huge wedding rings, with plasma inside from the heat generated by the compression. Add some lightning for the power surging from the superconducting coils and you're set.

 

Google Images "no blades fan"

[Heartofthewolf]

Okay, awesome responses everyone, thanks! I really appreciate the input...so it looks like my original idea has gone completely out the window. That's okay, though...exactly what i needed. I want to hear more about this "magnetically responsive atmosphere"...