So I Drew A Tank, Need Commenatary

[Hotfoot]

The plasma is at room temperature, as Admiral Vlad says. And it hides you from radar (but you yourself can't use radar too). So you'll have to use passive sensors, or active sensors that stick out of the plasma field.

Specifically microwave band radar. Never mind that radar is not as commonly used in tank warfare as it is in air warfare. Even in air warfare, flying below a certain altitude can bring you below rader's ability to find you effectively.

Which is perfectly fine, as Ra's tank is supposed to work against enemies with fancier sensors and crap.

It only works against microwave range radar, and maybe radio range. It does nothing against thermal or near IR, visual, or UV.

So, the plasma is not hot. It's room temperature.
It hides you from radar (and maybe other fancy pants stuff), which the enemy would use (perhaps heavily).

Not really. The biggest advancement in tank warfare has been thermal sights. This shield, while "room temperature" still generates heat on a cold night, and does nothing to mask the temperature of a combustion engine, to say nothing of the heat a fusion reactor would put out. Another thing you fail to understand is that such a cloak actually emits light in the visible spectrum, turning the tank into a glowing purple target in night time conditions (you can forget about camo, this has to be on the outermost layer of the tank for it to work).

It also helps mask the massive emissions your giant railgun makes.

No, sorry, doesn't work. You see, while light is an electromagnetic wave, the railgun relies on a very large magnetic field created by electrical current. On top of that, you'd actually need the plasma coating on the gun itself for this to work, and there will be considerable disruption of the plasma when faced with such a large force as provided by the railgun. For all we know, the plasma (which is generally contained in an elecromagentic field) would be stripped away or disrupted each time the gun fires.

You can see the enemy look for you with their radar, thanks to your passive sensors.

Sorry, but this is clearly wrong, unless you build passive sensors OUTSIDE of the plasma shield (which increases your sensor profile). The entire point of this system is that it stops pretty much all Microwave level radiation, both ways. So if you're cloaked, you're just as blind on your sensors as your enemy is.

You blow them away, and they won't know what hit them.

Perfect!

Sorry, but no. While this is a potentially useful advance for air warfare, it's nowhere near as useful for tank warfare. The only real use for this device is defense against EMP. That said, you might be able to use it to help lessen the EM disruption you would get from firing the main gun, assuming you could find a way to maintain the integrity of the plasma during the actual firing.

[Shroom Man 777]

Specifically microwave band radar. Never mind that radar is not as commonly used in tank warfare as it is in air warfare. Even in air warfare, flying below a certain altitude can bring you below rader's ability to find you effectively.

I know, but it's sci-fi, so it could work.

It only works against microwave range radar, and maybe radio range. It does nothing against thermal or near IR, visual, or UV.

Yeah, but those aren't "fancier sensors". If his sci-fi badguys use radar on the ground, then plasma cloaking will be good. And his tank has ways to counter thermal (active cooling system).

Not really. The biggest advancement in tank warfare has been thermal sights. This shield, while "room temperature" still generates heat on a cold night

Really? Fuck... I kind of thought it meant like "average background temperature". Gah. Well, we could make it an optional add-on.

No, sorry, doesn't work. You see, while light is an electromagnetic wave, the railgun relies on a very large magnetic field created by electrical current. On top of that, you'd actually need the plasma coating on the gun itself for this to work, and there will be considerable disruption of the plasma when faced with such a large force as provided by the railgun. For all we know, the plasma (which is generally contained in an elecromagentic field) would be stripped away or disrupted each time the gun fires.

Mmm... good point. We could reduce the disruption by having the railgun fire a slower round, a round equipped with a rocket-motor or something. But bah, that's contrieved.

Sorry, but this is clearly wrong, unless you build passive sensors OUTSIDE of the plasma shield (which increases your sensor profile). The entire point of this system is that it stops pretty much all Microwave level radiation, both ways. So if you're cloaked, you're just as blind on your sensors as your enemy is.

Yeah, but I did mention something about sensors that stick out of the plasma field. They could just be sticks that stick out a few inches out of the thing.

If the sensors that stick out are as big as a baseball, that won't really register to enemy radar.

That said, you might be able to use it to help lessen the EM disruption you would get from firing the main gun, assuming you could find a way to maintain the integrity of the plasma during the actual firing.

Handwavium. That, and it's the 24th century.

[frigidmagi]

No offense Shroom, but I rather have better answers than the old Star Trek standbys bro.

[Shroom Man 777]

... I knew it wasn't going to work :sad:

Come on, what's wrong with saying "this has a plasma-cloaking field that's t3h k3wl" and people going shiny eyed and like "wow! amazing!"? No questions asked. Like, how could Arnold hide in a tool shed, have like a hundred guys open up on it with automatic weaponry, and not only come out unscathed, but kill them all by decapitating them with pitchforks and impaling them with oversized circular saws?

Maybe I'm just silly that way.

[frigidmagi]

He can do it cause he's Arnould! Duh.

[Shroom Man 777]

Oh yeah... but it... this... its just like that! Arnold invented plasma cloak!

[Hotfoot]

I know, but it's sci-fi, so it could work.

It could, but you'd need a reason to use radar instead of thermal sights.

Yeah, but those aren't "fancier sensors". If his sci-fi badguys use radar on the ground, then plasma cloaking will be good. And his tank has ways to counter thermal (active cooling system).

I beg to differ. Thermal sights are much fancier than a radar system. Radar simply bounces EM waves off of things and waits for a response. IR and UV sights have to convert said frequencies over to visible light. Meanwhile, this device provides a fairly narrow range of protection against a technology developed in the earlier half of the century.

Really? Fuck... I kind of thought it meant like "average background temperature". Gah. Well, we could make it an optional add-on.

Especially in a desert where nights get really cold, it would be very noticable. Not nearly as much as an active tank, mind you, but enough to be picked up by, say, a thermal scope on a helicoptor like an apache or a cobra.

It all depends on the plasma, of course. The more effective plasma shields are denser ones, which have additional limitations and will increase average heat.

It is possible to stick your hand inside of cold plasma, though again, depending on the type, it's not generally a good idea, as they use room-temp plasmas to sterilize things by breaking down cellular structures.

Mmm... good point. We could reduce the disruption by having the railgun fire a slower round, a round equipped with a rocket-motor or something. But bah, that's contrieved.

Or potentially by using the plasma shield to dampen the EM field. I'm not sure of the physics behind room temperature plasmas, but I know that superconducting solids have a tendancy to match fields naturally (the levatating magnet you can sometimes see in some textbooks).

Yeah, but I did mention something about sensors that stick out of the plasma field. They could just be sticks that stick out a few inches out of the thing.

If the sensors that stick out are as big as a baseball, that won't really register to enemy radar.

True, but again I have to question really heavy enough use of radar in ground warfare to make this level of protection necessary.

Handwavium. That, and it's the 24th century.

Or by having the field be disrupted every time a shot is fired, requiring time between firings to re-establish the plasma sheath. Maybe even include the ability for the stuff to flow along with the field during the path of the shot, I'll have to re-establish my knowledge of the Lorenz force.

That said, the application of the technology to the tank can work, though maybe not entirely the way you first envisioned it doing so.

By the way, it's still useful for air warfare ;)

[Shroom Man 777]

So... cloaking the projectiles so radar that can trajectorize the shell and tell counter-arty where to shoot can't see 'em? That's actually a pretty cool idea!


Yeah, it's good for air warfare. But I want plasma-covered tanks!

EDIT:

And still, enemy radar filtering out basketball-sized things, even if said radar is uber advanced, does make sense. Would you want your radar to show everything from coyotes and land-squids to rocks and stones and tank-sensors?

As for the desert thing, you could just switch off your plasma. When the day gets hot, you could have your plasma get denser in order to match heat with the surrounding.

[Hotfoot]

More like cloaking the barrel so the EM from firing won't fry the rest of the tank's systems ;)

Once the rail is away, it's pretty inert, much like a tank shell.

One thing to remember is that the plasma won't absorb the heat from the Tank effectively. Say that the tank has a hull temperature of 30 C, and the plasma has an ambient temperature of 20C, the plasma will either get heated up to the tank's temperature (30C), or bleed the thermal energy very quickly, emitting it to the world. What would be worse if it retransmitted it in visible spectrum light. Imagine a cloaked tank that lit up a bright purple.

If the radar is really advanced, I'd imagine it would be able to distinguish a sensor suite from a rock or an animal.

Meanwhile, a bright purple glow coming to a head as the gun fires, that strikes me as being amazingly cool

[Shroom Man 777]

More like cloaking the barrel so the EM from firing won't fry the rest of the tank's systems ;)

Once the rail is away, it's pretty inert, much like a tank shell.

Damn! It'd be cool if the shell gets cloaked too!

One thing to remember is that the plasma won't absorb the heat from the Tank effectively. Say that the tank has a hull temperature of 30 C, and the plasma has an ambient temperature of 20C, the plasma will either get heated up to the tank's temperature (30C), or bleed the thermal energy very quickly, emitting it to the world. What would be worse if it retransmitted it in visible spectrum light. Imagine a cloaked tank that lit up a bright purple.

Why the hell would it glow purple?!

And Ra's tank (I read the technical stuff he posted elsewhere) has a cooling system.

If the radar is really advanced, I'd imagine it would be able to distinguish a sensor suite from a rock or an animal.

The passive sensor's just a piece of metal, how can it differentiate it from a rock or a hippo or a bird?

Meanwhile, a bright purple glow coming to a head as the gun fires, that strikes me as being amazingly cool

Hmmm... *takes note*

[Hotfoot]

Why the hell would it glow purple?!

That's what color most room temperature plasma seems to glow. It would vary, of course, depending on the gas you use, but it seems to be all noble gases, so presumably whatever color you'd get in a neon light would be close to what you'd get from the cool plasma.

And Ra's tank (I read the technical stuff he posted elsewhere) has a cooling system.

True, but one has to remember that the heat has to go somewhere. If you want to keep the tank stealthy, you want to keep the outside cool, keeping all the heat inside. On the other hand, if you want to keep the crew alive (and the equipment working) you need to bleed off heat away from the interior, which generally means out through the hull.

The passive sensor's just a piece of metal, how can it differentiate it from a rock or a hippo or a bird?

Depending on the advancement, it would be relatively easy to discern between a metallic object which has specific reactions to various types of EM energy, and flesh, which has different reactions.

Hmmm... *takes note*

I'd imagine the stuff would be pretty cool. You'd have a sheath of plasma, glowing a cool purple, building up as you get ready to fire, until you've got a purple-white light core rushing over the barrel in time with the projectile, extinguishing the light behind it, ending with a muzzle flash and a crack (depending on the projectile). Slowly, the barrel starts to glow again, an ominous countdown to annihilation...

[Shroom Man 777]

That'd be an excellently weird yet cool thing for these aliens I'm using. Yes. Though it can work with a plasma sheath and any heat-producing weapon, right?


As for the radar detection thing, why not cover the sensor in rubber? Or fur?

[Hotfoot]

I'd imagine it's only really possible for electromagentic weapons like railguns (I'm not even considering coilguns (gah) due to how horribly inefficient they are). However, depending on the level of tech, it could be entirely possible for man-portable rails (though honestly standard weapons would likely be best).

It may help with some energy weapons, such as Masers, actually. Depending on how you generate the microwave beam, there could be a lot of scattering that could really muck things up, and this sort of shield would be effective in stopping random scatter. It would also provide a level of defense against the weapon, but that's like saying "steel will protect the user of the rifle against the explosion of the powder" where a projectile propelled in such a manner can still penetrate steel.

Rubber or Fur covering could aid in some additional stealth, but in the end, you're going to want to leave the detection surfaces open in order to get data from it, so it's a tradeoff.

[Shroom Man 777]

But the detection surface (IR scopes, or whatever) is ridiculously small. Radar that can detect tanks is a different thing from radar that can discriminate between animals and tiny pieces of glass/plastic/metal.

'd imagine it's only really possible for electromagentic weapons like railguns...*snip*

I'm not talking about portable weapons. How about plasma? Masers, you already covered and approved, so yay!

I have an alien race that's a bunch of insects and mollusks. They've got insectoid mechs and insectoid buzzing aircraft. They've got plasma guns, pyrotechnic pulse-missiles (as in projectiles propelled by fancy glowy pulse-energy-things), and WOTW-ish maser heat rays. So making them even more glowy with plasma cloaking would be great!

[Hotfoot]

Plasma weapons presumably have some sort of electromagnetic bottle, so yeah, that would work as well.

Interesting note, a maser would be a pretty solid color (while a plasma or rail system would affect the shroud with each shot), though there might be dancing colors depending on how the plasma reacts to being bombarded with microwaves.

[Shroom Man 777]

I guess I'll make the plasma cloak an optional add-on that some human guys noticed on some alien war machines. Too lazy to edit all of the few articles on the aliens I've written.

[Ra]

Whoa, where to start...

Uh, yeah, I see the problems with a plasma-based cloak. Some serious drawbacks...

However, I'm still wondering about all the problems with railgun recoil. I made the barrel so long because I believed that longer barrels tended to need less force applied (due to linear acceleration). If the projectile isn't much faster than a current tank shell (most Union weapons are about as powerful as present guns, including firearms), would the recoil actually be greater than a comparable chemical gun?

Also, muzzle velocity is kept so low due to power costs. You could make a Quake-style hypervelocity railgun, but a power pack that will give you 100 shots (for the EK17 carbine) might give you two HV shots. Basically, Second Star-verse railguns are similar to the nBSG ones; just as "fast" as present-day firearms.

Regarding the problems with the gun frying the tank and its occupants, that's solved by shielding of some kind. The Union uses plasma-based engines capable of some pretty damn fast accellerations (a command ship can reach .50 c in over five to ten minutes, straining her drives). So shielding the crew from those engines and their high rad output (and possibly a mass-lightening effect, although I'm still musing that) is a tall order as well.

Also, as for using plasma cloaking to diffuse DE weapons, I had actually considered a similar idea for Union warships. They sprayed a diffuse plasma jet at particle and laser beams, to diffuse them. So, that's cool.

Plasma weapons? I don't use 'em. I prefer actual particle weapons, based on what Michael Wong said about B5 PPG's. Charged particle guns are used for heavy weapons on the ground, while neutral particle guns are used in space.
- Ra

[Hotfoot]

Whoa, where to start...

Uh, yeah, I see the problems with a plasma-based cloak. Some serious drawbacks...

However, I'm still wondering about all the problems with railgun recoil. I made the barrel so long because I believed that longer barrels tended to need less force applied (due to linear acceleration). If the projectile isn't much faster than a current tank shell (most Union weapons are about as powerful as present guns, including firearms), would the recoil actually be greater than a comparable chemical gun?

Nope. In fact, it's entirely possible to have a weapon with a longer barrel that has somewhat higher end velocities than a chemical gun with less recoil, exactly for the reasons you've stated. Chemical guns tend to have most of the acceleration at the point which the powder goes, whereas a railgun will spread it out a bit more. Granted, there's still acceleration in a chemical gun past the point of powder ignition as the gases continue to expand, but it's not quite as much as the forces involved in a railgun past the breach.

Also, muzzle velocity is kept so low due to power costs. You could make a Quake-style hypervelocity railgun, but a power pack that will give you 100 shots (for the EK17 carbine) might give you two HV shots. Basically, Second Star-verse railguns are similar to the nBSG ones; just as "fast" as present-day firearms.

Seems reasonable. Be fun for a few cases to overload them though, if the possibility exists. ;)

Regarding the problems with the gun frying the tank and its occupants, that's solved by shielding of some kind. The Union uses plasma-based engines capable of some pretty damn fast accellerations (a command ship can reach .50 c in over five to ten minutes, straining her drives). So shielding the crew from those engines and their high rad output (and possibly a mass-lightening effect, although I'm still musing that) is a tall order as well.

I don't think a railgun would fry the occupants, the primary concern is the EM causing damage to electrical systems. The first railgun tests back in the 60's (I think, been a while) caused a massive burnout in every instrument the tank had.

50% lightspeed in five minutes? You'd better have some sort of a-grav, or those people are beyond paste. ;)

Also, as for using plasma cloaking to diffuse DE weapons, I had actually considered a similar idea for Union warships. They sprayed a diffuse plasma jet at particle and laser beams, to diffuse them. So, that's cool.

Also could just make the outermost layer of the hull with a thin layer of plasma built into it.

Plasma weapons? I don't use 'em. I prefer actual particle weapons, based on what Michael Wong said about B5 PPG's. Charged particle guns are used for heavy weapons on the ground, while neutral particle guns are used in space.
- Ra

Plasma is a particle, of course ;)

[Ra]

Nope. In fact, it's entirely possible to have a weapon with a longer barrel that has somewhat higher end velocities than a chemical gun with less recoil, exactly for the reasons you've stated. Chemical guns tend to have most of the acceleration at the point which the powder goes, whereas a railgun will spread it out a bit more. Granted, there's still acceleration in a chemical gun past the point of powder ignition as the gases continue to expand, but it's not quite as much as the forces involved in a railgun past the breach.

I see now.

Seems reasonable. Be fun for a few cases to overload them though, if the possibility exists. ;)

Ha ha! That's not a bad idea. Dial up the shots, just when you HAVE to have that extra kick. Even so, I dunno if the barrel could handle it on a firearm.

I don't think a railgun would fry the occupants, the primary concern is the EM causing damage to electrical systems. The first railgun tests back in the 60's (I think, been a while) caused a massive burnout in every instrument the tank had.

True. Kinda like EMP effect, only over a much longer period of time. IIRC, one of the Voyager probes nearly fried from Jupiter's magnetic field.

50% lightspeed in five minutes? You'd better have some sort of a-grav, or those people are beyond paste. ;)

Yep, intertial comps come standard, as part of the artificial gravity system.

Also could just make the outermost layer of the hull with a thin layer of plasma built into it.

Interesting... I like that idea! That would also keep the plasma from blocking your view while driving the tank.

Plasma is a particle, of course ;)

True, but particle cannons rely on velocity rather than magnetic bottles.
- Ra