# A bit more effective force field

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AeT-Shield

The shield uses nanobots, that can form layers. The two most important layer types are, a permanent magnet layer, and the other is a conductor layer. Each layers are in a frame, and all frames have some type-1 super conductors. The shields shape is kinda like Zeruel's AT-field, but inverted.

1. When a projectile collides with the shield, it pushes the magnets into the conductors, this induces electric current.

2. The projectile decelerates, as it loses energy. Then the shield toses away the projectile( if the projectile is too strong then, it tosses it in a vector that avoids the user).

(Side note: sorry Master Chief hard light is impossible , also this pic doesn't includes the frame's superconductors)

• If the force is too big for the shield and the user is sent flying, the user would be decelerated, preventing fall damage.

• If the other methods would still result in the user's death, then the shield goes NIGHTMARE FUEL, and evaporates the projectile.

However these shield have a one big downfall: basicaly any attacks that transfer heath energy to the shield, especially plasma and lasers. And here's why:

• plasma can be quasi-neutral, which eliminates magnetic protection.
• Lasers are much more easier to defend aginst, a shiny, reflective layer is enough, to make the enemies feel themselves dumb.
• And the acidic is repelled with an inert layer.

If the shield is at the risk of overheathing, another emergency layer activates, and tries, to cool down the other layers, via through using some liquid nitrogen. This will impaire the users vision, but not for too long.

Other uses:

• Levitating over one spot.
• Fus Ro Dah and similar things.

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After 2 updates:
When the collosion is violent enough, the shield becomes visible. This is due to that another emergency layer activates, and tries, to cool down the other layers, via through using some liquid nitrogen. This will impaire the users vision, but not for too long.

After 3 updates:
However these shield have a one big downfall: basicaly any attacks that transfer heath energy to the shield, especially plasma and lasers. And here's why: plasma can be quasi-neutral, wich eliminates magnetic protection. Lasers are much more easier to defend aginst, a shiny, reflective layer is enough, to make the enemies feel themselves dumb.

Sorry if my english spelling and grammar sucks.

Update:
Opps I forgot the questions:

• What downfalls would the shield have?
• Is this shield even possible?
• Improvements on it?

Update2: Turns out, perma-magnets will lose all of their magnetic properties, when overheated. Solution? IMaFarinMahLAZOR.

Update3: I forgot to mention that frame superconductors are type one.

Update4: Changes in interception methods.

• Therefore ur shield can absorb and spread out excess kinetic energy while the materials and coatings take care of acid spills? But note that at high temperature magnets... to be continued. Jan 12 '17 at 12:18
• What does this shield do which ordinary armor doesn't do? Jan 12 '17 at 12:20
• @AlexP While working, it turns the user into an Implacable Man . At least in theory Jan 12 '17 at 12:28
• If it uses nanobots, it's hardly a force field, is it? It sounds like a giant piezo crystal en.wikipedia.org/wiki/Piezoelectricity Jan 12 '17 at 13:12
• @nzaman Welp, it wasn't a force field from the begining, it only just had the same function: protect the user in a way, that it's not gona fly, when hit by a rocket launcher. Jan 12 '17 at 13:19

## 3 Answers

When a projectile colides with the shield, it pushes the magnets into the conductors, this induces electric current, wich then used to slightly amplify the super conductor's power, so that they can separate the layers. Of course nothing can be 100 percently efficent in physics, so the shield will have to borrow some power from somwhere else. The cycle will continue, until the projectile runs out of energy.

The problem is that you still have to deal with Newton's Third Law. Whatever you do to the projectile's momentum, you'll be doing to the shielded volume in reverse. You can convert kinetic energy to electricity (or heat, or...), but momentum must be conserved.

What you want to do to a projectile is to decelerate it, and this usually happens in a very short time. High acceleration translates into massive forces since F = m*a, so you get a lot of damage.

You need lower accelerations, but acceleration is linked with space covered by the projectile: s = (v*v)/(2a). Which means that you need to get at the projectile when it's still a sufficient way out.

How this could work:

• detection. A swarm of nanobots has to keep tabs on the surrounding volume of space, basically getting the position of any non-nanobotic object. When such positions vary, their intercept is calculated and compared with safety parameters.
• interception stage 1. The nanobots need to have some way of communicating and pushing against one another. They do so, and accelerate towards the projectile. By doing so, the momentum of the cloud must be conserved, and specially selected and much more massive nanobots on the opposite side of the cloud get pushed backwards, in the same direction of the projectile. They are larger and heavier; if, taken together, they had the same mass of the projectile, they'd end up with its same speed. But they are many, and they are hairy. At low speeds air resistance is negligible; at higher speeds it starts growing and at high Reynolds numbers it goes up quadratically, so that air is being pushed backwards behind the shielded object.
• interception stage 2. The nanobotic swarm reaches the projectile and connects to it, then it starts pushing (a very hot, corrosive, liquid metal projectile would be the obvious counter, and breaking it into droplets and/or using contactless magnetic braking would be the obvious counter-counter). The momentums (momenta?) of the forward section of the nanobotic shield and the projectile are the same - actually, the swarm's will increase until it matches the projectile's - and the projectile is slowed down and/or pushed downwards or aside, if practical.
• twists: a judicious use of micro-lasers or handwavium disintegrating nanobeams (or very fast nanobotic buzzsaws) can break the projectile in two, then four, then... then 1,048,576 nanoprojectiles that will be individually captured, braked, and released.

At the macro scale, you see the projectile arrive, then a fogginess form in front of it, the projectile either stops after a couple of meters or disappears; behind the shielded person, a sudden powerful gust of wind, and/or a low-frequency sound like a WHOOOMP.

What is happening is that the shield is being pushed backwards (and deformed) by the projectile, while the shielded volume at the center is kept intact.

Another obvious counter: several projectiles on exactly the same trajectory, to push the shield so far back that the shielded object is uncovered. The nanobot shield requires a much larger time than the projectile to transfer the momentum to the air and become ready for the next projectile. Counter-counter: the swarm can communicate the momentum to surrounding objects (or best of all, floors and walls).

Of course, enough projectiles can saturate the shield's capabilities.

Creepy and totally impractical alternative solution: the swarm extrapolates the projectile's trajectory and quickly (but gently and carefully) block pain receptors and nerve transmission, separate the victim's skin, muscle, bone and organs creating a tunnel where the projectile may harmlessly go (provided it doesn't explode midway in a cloud of shrapnel and nerve poison), then knitting everything back together an instant later.

I don't think this would work.

1.) How would you make sure that all the nanobots remain in formation, instead of simply being attracted to the superconductor? You would need a very complicated balance to keep them at place.

2.) You cannot expect projectiles to act as perpendicular, steady forces. They would come from weird directions, and scattering on the shield, twisting nanobots, making them ejected, or colliding with other ones, thus disturbing the even distribution of nanobots, creating mechanical waves and interferency propagating on the surface of the shield. They could have proximity fuse too, exploding into superheated gases before impact, and thus bypassing your shield.

3.) How would you transfer the electricity generated in the conductor nanobots into the superconductor, while they are floating? It would be much easier to simply have conductors in a magnetic field, whose motion would induce currents in them, which, according to Lenz's law, would dampen their motion.

4.) I don't really understand the nature of hard light. If it is some form of fictional forcefield, why do you have to make up a scientifically pausible one? If it spreads linearly, projectors protruding the shield will be necessary too.

5.) Lasers would burn off and evaporate the nanobots without beeing repelled by the shield.

6.) Enemy projectiles might have cunning electromagnetic fields to perturb your shield. ( Twisting nanobots, making them ejected, or colliding with other ones.)

7.) Since it has magnetic field in it, it would, in fact, offer the best protection against plasma. (forcing charged particles to turn.)

8.) The user of the field won't be able to use weapons or sensors through it.

The idea of a shield is very much like the “swarm” I detailed on my Answer to hard sci-fi energy shields.

The enabling technology is flux pinning and the use of the superconductor to absorb the kenetic energy.

Making them tight organized layers though is more like My plausible supermaterial. You never said whether this is worn like a vest on a person or is protecting a space ship! The spread-out swarm is a much more effective shield because the impacted plate can fly off and not affect other plates. The supermaterial vest would be like a modern body armor, but be especially strong against breaking and change the material properties in response to an impact.

The solid light thing is nonsense. The wikipedia article you point to seems to cite only reporter’s hyped interpretations, nothing real. In any case it’s light moving through a nonlinear medium and would not be a thing in itself—you need the media. And what’s the point? Is this energised media supposed to have some useful properties? And the medium in question is an ultra-cold cloud of rubidium atoms—not something you could use as a building material.

If going the supermaterials route, I suggest using a layer of programmable matter. The surface facing the outside would have a coating of this material, which can be commanded to change its chemical nature to resist chemical threats to the material. Oh, and use it to have active camouflage while you’re at it.

Cooling: this has also been discussed before. You do not want to overload your superconductor! But laser cooling as you link to is not the kind of thing you would use here. That’s for grappling individual trapped atoms and sapping up any residual motion when you are at millikelvin. It has nothing to do with heat sinks on bulk material at room temperature.

I suggest you explore the site some more and go through the wealth of material that’s already been written on this subject. I’m glad to see someone else who thinks along the same lines as me, and I’ll be happy to help you work out details of your design.