Making a Magnetic Field into a Deflector Screen?

[Covenant]

I've been struck by this odd idea and wanted to mine the knowledge base here after sniffing around the web and Project Rho to no avail.

The Question:
If a starship designer wants to create a deflector screen for a starship using a minimum of technobabble, but with as much handwavium isotope as is required, how powerful is a magnetic field going to have to be to operate as a legitimate defensive measure against incoming kinetic kill attackers?

I specify kinetic kill, chiefly a guided projectile with a high interception speed relative to the target, because using a magnet to counter lasers is laughable, and the interaction of a magnetic field and (charged or neutral) particle beams is well known.

I'd also like to specify that having the field be tightly bound to the ship is NOT a design goal. I think the ideal EM Shield would give a nice big field bubble that helps shove things off-target rather than splat them or rattle the magnet's structural supports too much.

Presumably the projectile's casing and construction can be made relatively non-interactive with magnets in a best situation, but I wonder if sending this thing screaming off through space is going to give it a charge that would allow it to be slid off-target. Or if the projectile's own motor (fusion or antimatter, because why settle for second best?) would either create a charge or perform badly within the deflector's field of influence. Lastly, might it not also screw up the reaction of the missile, since the likely fuel sources are both often dependent on magnetic control?

Last question. What would this do to the interior of the ship using the shield? Is this the kind of thing that could be done in such a way that the interior is in the eye of the (magnetic) storm and doesn't suffer the ill effects of however many Teslas the field ends up being? If we dip into the Magnetic Monopole bucket, is there any way to sensibly fix such a problem?

I latched onto the idea of an excessively strong magnetic field after reading the "Physical Nature of Shields" article off in the sections of the site here that still house the STvsSW debate data. Without going bonkers and using entirely fake magic fields (or abandoning the idea of a shield entirely) I wanted to see what could be done with simpler measures. If you have a better idea, toss it in.

[cadbrowser]

Depending on how advanced your 'verse is and those in it. If your people are adapt to mining areas within the Galaxy, you could possibly have them mine or capture a neutron star or something more exotic (?) that due to it's sheer mass could serve as a deflector shield.

Taken from Wikipedia

Neutron stars contain 500,000 times the mass of the Earth in a sphere with a diameter no larger than that of Brooklyn, United States

So I guess instead of having magnets or even superconducting magnets, you could perhaps have enough of that stuff that would invoke a 1g gravitational pull or more depending on how far you want your object to "bend" out of the way. Shouldn't this work with lasers as well?

[Batman]

Depending on how advanced your 'verse is and those in it. If your people are adapt to mining areas within the Galaxy, you could possibly have them mine or capture a neutron star or something more exotic (?) that due to it's sheer mass could serve as a deflector shield.
Taken from Wikipedia

Neutron stars contain 500,000 times the mass of the Earth in a sphere with a diameter no larger than that of Brooklyn, United States

So I guess instead of having magnets or even superconducting magnets, you could perhaps have enough of that stuff that would invoke a 1g gravitational pull or more depending on how far you want your object to "bend" out of the way. Shouldn't this work with lasers as well?

And how exactly do you move that kind of mass without prodigous amounts of technobabble? Or keep your ship from crashing into it once it falls into the damn thing's gravity well?

Having a near infinite supply of handwavium available doesn't help you with the 'minimum technobabble' aspect if the only way to use that handwavium is excessive technobabble.

[Covenant]

I also think science argues against it. Neutron stars aren't made of terribly exotic materials, they're just an unusual environment. Mining the "stuff" of a Neutron star doesn't really yield anything interesting. If you had a Cosmic Straw to suck some of the neutron star soup out, it'd just turn back into basically normal stuff. They're magnets the same way the sun or the earth is, by spinning some stuff that is also really hot and has a lot of atomic chemistry going on. Compared to a potent electromagnet or something it seems like a really inefficient method for making a magnet.

Neutron Stars and Magnetars are interesting demonstrations of high-power magnetics but they're not really a power source or a model for creating your own, unless our interpretations of their nature is incorrect or they happen to kick off super powerful monopoles that can be harvested. Monopoles themselves aren't magic, even if they are interesting things, so even that's not a sure shot.

[Batman]

I don't think cadbrowser is arguing using neutron star matter to boost your magnets, he's saying 'forget the magnets-Go Gravity!' and use the damned thing's gravity well to move stuff out of your way (kinda like Honorverse sidewalls).

[Simon_Jester]

I've been struck by this odd idea and wanted to mine the knowledge base here after sniffing around the web and Project Rho to no avail.

The Question:
If a starship designer wants to create a deflector screen for a starship using a minimum of technobabble, but with as much handwavium isotope as is required, how powerful is a magnetic field going to have to be to operate as a legitimate defensive measure against incoming kinetic kill attackers?

Too powerful to be generated without technobabble. Also, too powerful for it to be remotely safe to be made out of conducting material anyone in the vicinity.

Examples of conducting material for these purposes include iron, steel, copper, and your torso.

Depending on how advanced your 'verse is and those in it. If your people are adapt to mining areas within the Galaxy, you could possibly have them mine or capture a neutron star or something more exotic (?) that due to it's sheer mass could serve as a deflector shield.

Taken from Wikipedia

The problem then is that your shield is stupidly, ridiculously heavy. If you have engines powerful enough to move such a stupidly heavy thing, you could easily build a spaceship hundreds of miles across, move it with considerably less effort, and just have the thing be so damn big that it laughs off impacts from megaton-range weaponry.

[Covenant]

Too powerful to be generated without technobabble. Also, too powerful for it to be remotely safe to be made out of conducting material anyone in the vicinity.

This answer seemed all too likely, and similarly all too depressing.

Are we basically saying that, even if we're not aiming for hard science at all, the creation of a starship-bound mobile "force field" that deflects incoming projectiles is going to be bullshit of the highest caliber? In the "Six Degrees of Realism" game, how many degrees of separation is there between anything remotely Deflector-y and a common sense scientific basis? Just having it be plausible doesn't mean it doesn't sound like nonsense. I fear that we're looking at too many jumps.

Deflector screens of any make or model are exceptionally cool devices, and they have really exciting narrative implications, but in a rather predictable way they always seem to violate both science, common sense, and internal consistency. Even in a "pick two" scenario I don't like that very much at all. Technobabble isn't always bad, and it isn't always a sign of a bad writer (or even of a writer who disrespects science), but it always triggers the same part of my brain that wakes up when I see something that looks like bad CGI. I'd rather save it for things that can be wondrous, not just expected.

I'm also not thrilled with the idea of using a substantially weaker, yet still entirely lethal/problematic magnet that traps plasma or interceptor particulate or whatever. That's just taking a questionable solution and adding another questionable solution on top of it. Obviously, the easiest way to make an impassible EM barrier that is opaque to lasers and resistant to kinetic kill weapons is to just throw up your hands and slap some armor onto the hull and say "There's your damned force field! Protons and electrons held in mutual suspension!"

[Dass.Kapital]

*Raises hand*

I do remember reading some where about using magnetics to help 'suspend' small particles at a certain distance from the hull. Basically., you turn the fields on, squirt the fine magnetic powder of what ever out into the fields and have a 'replenish-able' wipple shield 'out there' to have the KKK things ablate through before they get to said hull.

Just posting an idea, don't remember much more than those basics. Hope it helps.

Much cheers to all.

[cadbrowser]

And how exactly do you move that kind of mass without prodigous amounts of technobabble?

Why do you need any amount of technobabble to begin with? It works because he says it works.

Seriously tho, he asked for ideas, I just threw that out there willy nilly.

Or keep your ship from crashing into it once it falls into the damn thing's gravity well?

Dyson Sphere?

On the flip side, the other idea was a way to mine it. Course, that'd have some serious handwaiving too. You wouldn't need that much of the star's nuetron material to equal 1g. Then you could build a ship around a pea or marble sized piece.

I don't think cadbrowser is arguing using neutron star matter to boost your magnets, he's saying 'forget the magnets-Go Gravity!' and use the damned thing's gravity well to move stuff out of your way (kinda like Honorverse sidewalls).

Yes, that is what I was going for.

The problem then is that your shield is stupidly, ridiculously heavy. If you have engines powerful enough to move such a stupidly heavy thing, you could easily build a spaceship hundreds of miles across, move it with considerably less effort, and just have the thing be so damn big that it laughs off impacts from megaton-range weaponry.

Again, I was just throwing an idea out there. As per the OP, he wanted minimum technobabble, and as much handwavium isotope as required.

So, he could just state, "gravity-well shielding" : "neutron core" : "mined" - or whatever.

Keep in mind it also displaces the need for artificial gravity generators.

Are we basically saying that, even if we're not aiming for hard science at all, the creation of a starship-bound mobile "force field" that deflects incoming projectiles is going to be bullshit of the highest caliber?

That's what it sounds like to me.

I do remember reading some where about using magnetics to help 'suspend' small particles at a certain distance from the hull. Basically., you turn the fields on, squirt the fine magnetic powder of what ever out into the fields and have a 'replenish-able' wipple shield 'out there' to have the KKK things ablate through before they get to said hull.

Fine magnetic powder? How would that ablate a KKK thing again? Would this be like a swirling mass in constant motion around the star ship?

---

Why not something similar to what we actually do here on Earth? We don't build huge "magic" domes around our cities for incomming missle attacks. We build interceptor missles to destroy inbound threats. Or even a chaingun on a battleship to shred missles to pieces (Under Seige).

Wouldn't that be easier to do?

Maybe a "grey goo" interceptor missle system that feeds on whatever threat effectivly dismembering it before it gets close to the hull (The Day the Earth Stood Still).

[Lord of the Abyss]

Keep in mind it also displaces the need for artificial gravity generators.

Charles Sheffield was fond of that kind of thing. He had multiple stories where people generated strong gravity fields by the simple expedient of large chunks of superdense material. I recall his "Balanced Drive", which let ships carry passengers safely while accelerating at 50-100 gravities by having a disc in front that was massive & dense enough to counter the acceleration with its own gravity. Of course, it required a vacuum energy based engine to move all that mass any distance...

[cadbrowser]

A vacuum energy engine huh? That reminds me of the Alcubierre drive based on the Casimir effect, well without the huge disc in front anyway.

[Simon_Jester]

Are we basically saying that, even if we're not aiming for hard science at all, the creation of a starship-bound mobile "force field" that deflects incoming projectiles is going to be bullshit of the highest caliber? In the "Six Degrees of Realism" game, how many degrees of separation is there between anything remotely Deflector-y and a common sense scientific basis? Just having it be plausible doesn't mean it doesn't sound like nonsense. I fear that we're looking at too many jumps.

Basically, you need a way to say "I want an umpty g gravitational, electric, or magnetic field, pointing THAT way, at a distance." Which you can't really do just by physically piling up masses, charges, or currents.

Once you can do that, deflector fields become more practical. Of course, so do tractor and pressor beams.

I'm also not thrilled with the idea of using a substantially weaker, yet still entirely lethal/problematic magnet that traps plasma or interceptor particulate or whatever. That's just taking a questionable solution and adding another questionable solution on top of it. Obviously, the easiest way to make an impassible EM barrier that is opaque to lasers and resistant to kinetic kill weapons is to just throw up your hands and slap some armor onto the hull and say "There's your damned force field! Protons and electrons held in mutual suspension!"

Frankly, yes. Also, it's the area where you can do the most handwaving with the least violation of SOD, because it is (at least for now) still credible that we can use nanotech to produce in vats a variety of materials with truly excellent mechanical properties.

On the flip side, the other idea was a way to mine it. Course, that'd have some serious handwaiving too. You wouldn't need that much of the star's nuetron material to equal 1g. Then you could build a ship around a pea or marble sized piece.

A chunk of neutronium heavy enough to generate a 1g gravitational field at close range would still weigh... a whole lot of tons. Billions? More?

Again, I was just throwing an idea out there. As per the OP, he wanted minimum technobabble, and as much handwavium isotope as required.

So, he could just state, "gravity-well shielding" : "neutron core" : "mined" - or whatever.

Keep in mind it also displaces the need for artificial gravity generators.

Again, the problem is simply that with engines of such power he has little need for shielding of any kind.

[cadbrowser]

I understand where you are comming from Simon_Jester, and on the whole I agree with your objections to my "gravity-well" shielding.

[Guardsman Bass]

I'm also not thrilled with the idea of using a substantially weaker, yet still entirely lethal/problematic magnet that traps plasma or interceptor particulate or whatever. That's just taking a questionable solution and adding another questionable solution on top of it. Obviously, the easiest way to make an impassible EM barrier that is opaque to lasers and resistant to kinetic kill weapons is to just throw up your hands and slap some armor onto the hull and say "There's your damned force field! Protons and electrons held in mutual suspension!"

What about some type of Smart Armor, coming out of the reactive armor development line? Your ship's armor plating could be layers of thousands of smart panels that detach from the ship and form a cloud around the ship while it's drifting (maybe you could use magnets to keep them in the vicinity of the ship if it accelerates). If a project is in-bound, they can maneuver into the way of it and explode reactive-armor style. I remember Sea Skimmer proposing something like that in a prior space thread. And when you run out of layers, the ship returns to dock and gets them put back on.

[fgalkin]

Keep in mind it also displaces the need for artificial gravity generators.

Charles Sheffield was fond of that kind of thing. He had multiple stories where people generated strong gravity fields by the simple expedient of large chunks of superdense material. I recall his "Balanced Drive", which let ships carry passengers safely while accelerating at 50-100 gravities by having a disc in front that was massive & dense enough to counter the acceleration with its own gravity. Of course, it required a vacuum energy based engine to move all that mass any distance...

What happened when the ship stopped accelerating?

Have a very nice day.
-fgalkin

[Terralthra]

On the flip side, the other idea was a way to mine it. Course, that'd have some serious handwaiving too. You wouldn't need that much of the star's nuetron material to equal 1g. Then you could build a ship around a pea or marble sized piece.

A chunk of neutronium heavy enough to generate a 1g gravitational field at close range would still weigh... a whole lot of tons. Billions? More?

Yeah, but even so, once you take a teaspoon of neutronium out of the neutron star, it would stop being degenerate matter in fairly short order. It's only neutronium because of the immense gravitational force within which it exists. Remove that, and it's just going to go back to being ordinary baryon matter.

[Simon_Jester]

Yes- although I've heard it theorized that with the right container you could at least store electron-degenerate matter (i.e. white dwarf star cores) in a container made out of atoms. A very STRONG container.

[biostem]

Y'know what I would find impressive - a starship that is able to mount some sort of point defense system, (perhaps very powerful lasers), that can either outright disintegrate incoming projectiles, or ablate them to such a degree so as to cause a jet of matter on them that is sufficient to deflect them from hitting the ship's hull.

[Simon_Jester]

The main problem with this is the requirement for active targeting- you have to know the enemy is coming to shoot at it with a laser. The 'shield' classically occupies a passive defensive niche- it works even against an enemy weapon you can't see coming, or one that spoofs you into mis-estimating its position.

[Lord of the Abyss]

Keep in mind it also displaces the need for artificial gravity generators.

Charles Sheffield was fond of that kind of thing. He had multiple stories where people generated strong gravity fields by the simple expedient of large chunks of superdense material. I recall his "Balanced Drive", which let ships carry passengers safely while accelerating at 50-100 gravities by having a disc in front that was massive & dense enough to counter the acceleration with its own gravity. Of course, it required a vacuum energy based engine to move all that mass any distance...

What happened when the ship stopped accelerating?

The ship looks like a plate with a pole sticking out of the middle of it, with the engine on the far end of the pole and the crew compartment attached to the middle of the pole. The crew compartment moves up and down the pole, nearer to the super-dense disc when accelerating, and retreating from the disc and its gravity when accelerating more slowly or not at all.

[Simon_Jester]

The only way that works is if the pole is stupidly long and the disc is stupidly wide. Otherwise (say, if the disc has diameter comparable to the diameter of the habitat)... yeah. What's going to happen is that for people standing on the edges of the habitat, "down" doesn't point in anything like the same direction it would for someone standing on the centerline of the habitat. Tidal forces across a room may be quite noticeable (say, one side of the room is experiencing a relative acceleration of 1.5g when engine thrust and the plate's gravity are factored in, while the other side is experiencing 1.2g). You'd have to actively flex the floors to make sure they remain at right angles to the local acceleration vector as you slide the habitat along the pole, and if you don't then the contents of most rooms will want to "puddle" in whichever corner is closest to the centerline of the habitat.

The alternative is to make the plate much, much larger in radius than the habitat so you can get a roughly uniform gravitational field along the central axis.

[Covenant]

What about some type of Smart Armor, coming out of the reactive armor development line? Your ship's armor plating could be layers of thousands of smart panels that detach from the ship and form a cloud around the ship while it's drifting (maybe you could use magnets to keep them in the vicinity of the ship if it accelerates). If a project is in-bound, they can maneuver into the way of it and explode reactive-armor style. I remember Sea Skimmer proposing something like that in a prior space thread. And when you run out of layers, the ship returns to dock and gets them put back on.

After the comments so far, I'd consider stuff like this the way to go. Shields are extremely valuable from a narrative perspective because it allows people to do things things with a starship that they shouldn't, but advanced armors may be a much easier way to handle those kinds of narrative requirements without as much intentional destruction to science, or as least not as much casual destruction to science. Shields often end up as an assumed, never spoken of in depth, and never examined in any way. It's just "Shields up!" and then "Shields weakening!" or whatever. Useful tool, but I'd rather save my "magic just do what I say" black box device points for other stuff, like FTL.

Using an EM shield was an attempt to limit the abilities of the shield in order to make it seem more reasonable. But if it can't be reasonable, then there's really no reason to have it. From a narrative perspective there's no reason that nigh-invulnerable materials and active armor defenses would challenge your suspension of disbelief more than a magic energy field that we already know can't work the way we want it to.

[Irbis]

The Question:
If a starship designer wants to create a deflector screen for a starship using a minimum of technobabble, but with as much handwavium isotope as is required, how powerful is a magnetic field going to have to be to operate as a legitimate defensive measure against incoming kinetic kill attackers?

1. Encase nonmagnetic projectile in iron can;
2. Fire, then use explosives to jettison can away;
3. Laugh at screen as projectile effortlessly penetrates it?

Depending on how advanced your 'verse is and those in it. If your people are adapt to mining areas within the Galaxy, you could possibly have them mine or capture a neutron star or something more exotic (?) that due to it's sheer mass could serve as a deflector shield.

And how are you going to keep it together? Because even if you can somehow mine it, without pressure outside it's going to explode with energy approaching antimatter.

Y'know what I would find impressive - a starship that is able to mount some sort of point defense system, (perhaps very powerful lasers), that can either outright disintegrate incoming projectiles, or ablate them to such a degree so as to cause a jet of matter on them that is sufficient to deflect them from hitting the ship's hull.

It could be easily defeated by dispersing projectiles. Your laser can vaporize 2 projectiles per second? Fine, we're going to make each projectile splinter into 40 parts, good luck getting them all in 10 second intercept window you have.

What about some type of Smart Armor, coming out of the reactive armor development line? Your ship's armor plating could be layers of thousands of smart panels that detach from the ship and form a cloud around the ship while it's drifting (maybe you could use magnets to keep them in the vicinity of the ship if it accelerates).

Smart armour is nice and well, but I'd be wary of using something that slowly stops defending you against meteorites and projectiles from all directions regardless of where enemy attacks you. Such armour needs solving 2 very different issues before it can be decided viable, defeating attack concentrated on one point and always offering some protection from all sides against tiny particles space is full of even if it was partially depleted.

[Me2005]

What about some type of Smart Armor, coming out of the reactive armor development line? Your ship's armor plating could be layers of thousands of smart panels that detach from the ship and form a cloud around the ship while it's drifting (maybe you could use magnets to keep them in the vicinity of the ship if it accelerates).

Smart armour is nice and well, but I'd be wary of using something that slowly stops defending you against meteorites and projectiles from all directions regardless of where enemy attacks you. Such armour needs solving 2 very different issues before it can be decided viable, defeating attack concentrated on one point and always offering some protection from all sides against tiny particles space is full of even if it was partially depleted.

I see it more as some kind of advanced Whipple shield, where the armor panels disperse to extreme distances from the ship (hundreds of meters) on release and burst into a cloud of smaller particles. Some kind of magnet would try to keep the particles in place, but some are going to be lost if you maneuver hard. They won't be able to stop some larger projectiles reasonably (ships, asteroids), and will be less effective against incoming objects with low delta-V. But then you'd have the ship's armor, point defenses, and presumably a more traditional Whipple shield or foamed metal closer to the ship.

The armor wouldn't need to be stored as panels either, it could just be a central repository of particles that are disbursed in the direction needed. The particles that are used would vary based on your universe, but could also vary in-universe based on mission load out.

[Starglider]

Yes- although I've heard it theorized that with the right container you could at least store electron-degenerate matter (i.e. white dwarf star cores) in a container made out of atoms. A very STRONG container.

The pressure required to keep electron degenerate matter stable is on the order of 3 x 10^12 pascals (~30,000 bar). A few industrial processes (in particular diamond manufacture) achieve these pressures, albeit briefly over tiny areas using massive presses. So it is possible in principle although it is unclear how you are going to break through the non-degenerate matter crust or indeed get anything up the >100,000g gravity well.

For comparison the pressure required to keep neutronium stable is approximately 4 x 10^28 pascals. Nothing made of normal matter is remotely strong enough to withstand that.