Sci-fi Shields

[Rasori]

This was brought up in a thread earlier: http://www.scienceforums.net/forums/showthread.php?t=5124&page=2&pp=20&highlight=shields and I know that, so don't reference me to that. But, in that thread the subject was ignored and then the question I want to bring up wasn't answered- and I don't want to revive an effectively dead thread.

Anyway....

 

In the future, when shields as we see them in sci-fi movies would be possible, I see three main types of weapons: gauss rifles (rail guns, gauss cannons, whatever) with magnetized rounds, explosive propelled projectiles (missiles), and lasers. We have lasers now that have destructive capabilities, it doesn't take much of a stretch of the imagination to imagine weapons-scale lasers.

 

Here are the two shield theories I have to counterract these three weapons. My question to you is: would any of them work, and why not (if the answer is no)?

 

Shield #1, projectiles: Because we are considering the weapon of choice as gauss rifles for projectiles, we're talking high-velocity magnetic rifles. Obviously, for a magnetic rifle, you need magnetic rounds. So, what's wrong with creating an electromagnetic (or conventional magnetic, but that'd be damn hard) field that will either repel said rounds or attract said rounds to it- attracting works nearly as well because the projectile will slow down and change course once it gets past the pull-push boundary of the field, and change course a little beforehand. As for missiles, these would likely be made of materials that are magnetic (though likely not entirely) so they could be acted on in much the same way. The main downfall is the possible effects of an electromagnetic field this size, but by this point I'm sure we'll have plenty of stuff to help defend against it, as well.

 

Shield #2, lasers: I don't know how this could be made, but the concept is simple enough. Ordinary light is scattered, whereas lasers are coherent. Would it not be possible to, in some way, block out coherent light? Granted, this would also have some ill side-affects most likely, namely the possibility of blocking out some things that we'd want to see- maybe natural phenomenon, maybe... who knows? Even so, the safety it would (theoretically) provide would likely make it worth the while.

 

Could anyone tell me if, in theory, these could work? By the same token, if anyone has any ways to actually make shield #2 work (instead of just being a concept of what it would have to do) I'd like to hear them. And anything I overlooked (especially in the ways of other weapons- I'm sure that missiles, gauss rifles, and lasers aren't the only weapons of the future...) I would like corrected, if you could.

[TimeTraveler]

Well hopefully there is never a need for weapons in space but, one side effect I see from shield #1 is the attraction aspect could pose dangers in attracting large unwanted space debri chunks. Im no expert but it would seem reasonable that the attraction field would have to be fairly powerful to be able to affect rounds at such high speeds, I am not sure how this might affect smaller meteorites and other potential dangerous debris in space.

 

Fun and interesting topic though, thanks for posting it!

[swansont]

In the future, when shields as we see them in sci-fi movies would be possible

 

That's assuming the barriers to the shields are technological. Many of them are contrary to the laws of physics.

[Skye]

I imagine you could get around the EM shield by using a flechette style guass gun. Then the shell wouldn't need to be magnetic.

[Rasori]

I don't know nearly as much as I should about electromagnetism to really be arguing anything you said, but I was under the impression that it's pretty manipulatable (is that a word?). And I was going to get to a point through that, but then I remembered something- metals that are attracted to magnets are attracted regardless of which pole, are they not? That is, iron is attracted to a magnet regardless of whether it's at its north or south pole.

 

So then repelling with the EM shield wouldn't work, so you'd have to have some sort of protection against meteroites and debris. The first thing that comes to mind would be a major waste of power and very dangerous to allies. However, if you have more than one of these EM shields up, would it be very hard to 'confuse' the metorites and debris by attracting them every which way?

 

swansont, yes, that's true. However, we're going to play a little assumption game and say that with the right technologies the laws of physics are contrary to them

 

I'm trying to do some research on flechette-style weapons, but mostly they're links to sci-fi sources or just side-referencing. If you could give me information on it, Skye, I'd be grateful.

[Skye]

Sorry, I meant a the type of flechette that is enclosed within a sabot. That would have made it doubly confusing. A flechette is a little arrow type projectile, and a sabot is basically a casing that fits around a projectile that is smaller than the bore of the gun. This forms a seal with the barrel, but once the sabot+projectile leaves the barrel, the sabot falls away and the projectile continues on it's merry way. So you could have a magnetised sabot, and the projectile (the flechette as I was thinking) could be non-magnetic.

[Rasori]

Ahhhh. That makes much more sense Can't think of anything to counter that right now.

 

One advantage to the EM shields that I just realized now- any ship that uses any kind of magnetic gun couldn't use them. The EM shield would have to be much more powerful than the gauss gun's magnets and would really interfere. How's that an advantage? Well, equip your ships with EM shields and lasers, and hope they don't have laser protection On a more serious note, however, were you to get close enough to a ship with magnetic weaponry, the EM shields would be able to pretty much disable all of that weaponry.

 

That brings up another point- the laser shields, if they were to ever work in the way I suggest, would prevent a ship from having lasers. Unless, of course, you: a- bring the shields down to fire or b- have the laser cannons poke through the shields.

[YT2095]

for a Laser, "Blocking" is NOT a good idea, Reflecting is though, when you "Block" you Absorb, and you`de better pray that your blocking medium is up to the job!

when you reflect, there no danage done to YOU, and if you`re lucky enough to 180 it then you`ll blow the firing lasers cavity!

 

Ever seen a scorpion sting itself to death? ))

 

as for EM types like gauss guns, why not use the same as reactive arnour on some tanks? effectively it`ll mean you fire your OWN gauss gun when the em feild is detected from the assailant to deflect it,

 

I push a manget towards a tin can, it gets pulled in, but on it`s way it "sees" a strong magnetic pull, and never touches the tin can

 

 

just a thought or 2 )

[Rasori]

Reflecting is a valid point, but the only way I know of to reflect light is to have a reflecting medium somehow connected to the ship. I dunno about you, but I get the impression that a laser will melt a mirror down long before the mirror reflects the laser.

 

Looking at what information I have on reactive armor, that could be workable. However, gauss rifles are expected to be able to launch rounds at at least 11 km/s. That means that if you're within... oh, I don't know, 5 km?- then your shields won't have time to react to the shots being fired.

 

But what could work is if you were to divide the ship into 4-8 defensive regions. Each region has its own EM field generator. Knowing the position of the enemies firing at you, you could activate the regions that are safe. By doing this, you can change the course of the round, so if the EM shield itself (the concept I provided, that is) doesn't work, you can get a glancing blow instead of a direct hit. Depending on how surrounded you are, this could work especially well if they're firing at your fore, because activating the port-aft or starboard-aft EM shield would get you either a straight course to nowhere or such a glancing blow that it'll bounce off. Combined with rounded or sloping armor, much like tanks of today, you can get a pretty defensible ship. Plus, since only the safe areas are shielded, you still allow for all of your useful guns to fire- and possibly unpredictably, as they WILL still be affected by your own shield, causing it to go off on possibly different vectors. This is both good and bad- good because it will confuse the enemy, and bad because it'll throw off your aim unless you get good enough computers to compensate.

 

Thanks, YT, because you lead me into that direction

[Sayonara]

Ever seen a scorpion sting itself to death? ))

They don't.

 

 

The problem I see with energy shields is that - although we could theorise ways of building a defense against one kind of attack, sheilds would be useless unless they were able to repel all the most common forms of attack that were expected.

 

E.g. if you have a shield that can reflect high power lasers, and I come back with a projectile weapon, you're defenceless.

 

It would probably be a better use of time and energy to devise better evasive strategies, smart decoys etc.

[YT2095]

They don't.

 

are you SURE?

 

when exposed to extreme heat and certain chems, the natural reflex is to avoid it, and thus sting themselves.

it`s not Deliberate like Suicide, just a reflex

[Sayonara]

Yes, I am sure.

[YT2095]

Interesting, where did the idea and vid footage come from in these Nature programs?

or was it something else and thought to be (misinterpreted/wrongly) as stinging itself?

[Sayonara]

There are some that stridulate (as in, make a rasping noise in mating rituals or as a warning signal) by rubbing their telson against the metasoma, which may very well look as if they are trying to sting themselves.

[YT2095]

You`re obviously an Expert in this area, as non of that means a thing to me

 

not to worry, I`m sure you`re probably right though

[Rasori]

The point of making shields is to make them defend against weaponry. Since you don't need a hand to hold an energy shield or weapons, however, you aren't limited to just one weapon and one shield, two shields and no weapons, or two weapons. You can have hundreds of weapons and as many shields as there are generators that can fit in a ship. So if you develop shields to defend one type of weaponry, then develop evasive tactics for when shields fail or another weaopn comes, you have the best defense you can. You can include both of the shields I'm suggesting, however, in just one ship if you need to.

[YT2095]

Another idea occured to me last night regarding this, how about the battlefeild version of "Squid Ink" a pure white Smoke screen (I know they use this on a small scale already) but if the Dye were Dense and perfectly White enough, a laser would have a hard time penetrating and missiles couldn`t aquire the target, with the added advantage that you can hit what you cant see.

 

I then wondered if this would work in Space? could a pure white "smoke" cloud exist in space?

[Sayonara]

The point of making shields is to make them defend against weaponry. Since you don't need a hand to hold an energy shield or weapons, however, you aren't limited to just one weapon and one shield, two shields and no weapons, or two weapons. You can have hundreds of weapons and as many shields as there are generators that can fit in a ship. So if you develop shields to defend one type of weaponry, then develop evasive tactics for when shields fail or another weaopn comes, you have the best defense you can. You can include both of the shields I'm suggesting, however, in just one ship if you need to.

You're ignoring the fact that the cost of this vehicle would probably make it prohibitive as a weapon or defence.

 

Also, multiplying the number of complex systems and redundancies is just begging for something to go horribly wrong.

[Rasori]

Sayo... we're talking about the future when we actually need space weaponry and stuff. The cost would be prohibitive, but so would the cost of a ship without it.

 

The cost of a modern-day stealth fighter like the F-22 is very prohibitive, so they add more stealth features (at a bit of a higher price) in order to keep it from going down. So the ship that would have these shields would be high-priced anyway, so by adding shields they protect their investment better.

 

And we already have too many complex systems and redundancies--nothing's perfect.

 

YT- that's something to look into. In space, the cloud would be whisked away much quicker than in an atmosphere, but that doesn't necessarily mean that it wouldn't last long enough to help out.

[Sayonara]

Sayo... we're talking about the future when we actually need space weaponry and stuff. The cost would be prohibitive' date=' but so would the cost of a ship without it.

 

The cost of a modern-day stealth fighter like the F-22 is very prohibitive, so they add more stealth features (at a bit of a higher price) in order to keep it from going down. So the ship that would have these shields would be high-priced anyway, so by adding shields they protect their investment better.[/quote']

Notice how they add stealth technology to the F-22, instead of adding more armour, magnetic repulsors, missile-loc radio jammers, chaff guns, and bigger engines to carry that lot.

 

Making your unit less likely to be attacked in the first place is a lot cheaper (and often easier) than handling actual attacks.

[YT2095]

Looking at what information I have on reactive armor' date=' that could be workable. However, gauss rifles are expected to be able to launch rounds at at least 11 km/s. That means that if you're within... oh, I don't know, 5 km?- then your shields won't have time to react to the shots being fired.

[/quote']for some reason this has been bugging me for quite some time and I didn`t know why, here`s why!

 

11/kms is about the same rate of "burn" as detacord.

why use Gauss guns at all when ye Currently have weapons that will outdo any sort of gauss gun tech available?

 

the Tank Buster missiles have a SC nose cone (bacicly a concave copper disc in a tube packed with H.E) at a pre-determined distance from the target (a few meters) the SC detonates and sends a jet of nearly ionised copper clean through the tank! at similar and greater velecities than you`ve outlined already

 

the "beauty" of these is that unlike a "Dumb" projectile, these missiles are "smart" and guideable right up to BOOM time

[JaKiri]

Are they aspect seeking or fly by wire?

[YT2095]

aspect mostly, there are TOW versions though, but they`re normaly vehicle mounted.

[Rasori]

Obviously I don't know the costs of any of this, but I would assume the reason that gauss guns would be used rather than Tank Buster-type missiles is cost. I think a magnetic round would be much cheaper to produce than a "smart" weapon. And I'm sure that, since we're assuming we have the technology to power these shields and the ship at the same time, we'd be able to extend the reach of the shields (pump more power into them) in order to mess up the missiles--that is, either mess up their computer components or change their trajectory--as defense.

 

Granted, however, that these missiles are a good possibility for weapons choices.

[YT2095]

thats why most of the mil spec stuff use GaAs technology, it`s largely immune to EM radiation and that was late 70`s tech!

 

lord knows what they have now!