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TrAI
2003-Jul-09, 11:55 AM
One of the many strange things in Star Trek are the ships shields. They are usefull enough, the navigational deflector is in fact a very usefull thing, protecting the ship from being wrecked by micrometeorites and such things. Of course it is a mystery how the shields work but that is for another thread.

One of the properties of the shield is that it is not constantly activated, it apperantly is modulated in some way. The thing is that if you know this frequency you can fire through the shield.. We also know that the ships sensors can detect the shields of other craft. So I wounder why they don't just wire a frequency counter/waveform analyzer to the sensors and then feed this data to the phasers... They may have to time this, since they probably must deactivate their own shields for a moment, or adjust it to the same frequency as their enemy, but still, it might be usefull with such a strategy, the federation shields seems to go below 10% just by sneezing at it, you know..

Also the weapons of the enemy would be modulated with the frequency of the enemy vessles shield, so if they hit your shield, the shield monitoring things might be able to extract the frequency of this weapon...

man on the moon
2003-Jul-09, 12:47 PM
true true, somitimes you would think the ships would be better off just trapping some sheet metal to their hulls...

as for the deflectors vs. shields...i always figured they were the one and the same. difference being shields suck a lot of power while deflectors don't. they do serve the same purpose...only thing that changes is how BIG a thing they have to block.
it would sort of be the difference between lighting a candle and lighting a fire. they both make light, but a fire burns more fuel--and if you only need to get up the stairs without stubbing a toe, a fire would be overkill.

as for how they work? better not ask me! i just know i'd be glad to have one so, as malcom reed said, " a piece of dust would knock a whole the sive of your fist in the hull...". can't have that happening! :o

Russ
2003-Jul-09, 04:49 PM
According to the "Star Trek Technical Manual" shields use phase modulation repultion technology to block incoming energy. When they incoming is a light phase or particle beam they match the freq. and exceed the power. This is a rather brute force approach. I would have designed them to absorb incoming energy and convert it to matter ala Einstein's E=MC^2, route it through the transporters and make whatever valuable you need. You could get gold, platinum, etc. to any quantity you want without having to divert power from your propulsion system.

man on the moon
2003-Jul-09, 06:14 PM
wow, now i like that idea russ! i need one of those! (got a few school loans to pay off...a telescope to buy...a sailboat to buy...hmm... :D )

wedgebert
2003-Jul-09, 06:57 PM
Only problem with Sheilds are that they are EXTEMELY bad astonomy (bad physics actually).

With our current understanding of physics, there is no way for us to design any kind of force field. Not now, not 1000 years from now. It's not a matter of technology so much as a matter of there's nothing in physics that would allow for such effects.

We've only got four fundmental forces to work with, three of which are attractive only (Strong, Weak, Gravity). You can use electromagnetic fields to divert charged objects, it's not a "shield". And since most weapons (fictional and real-life) are electrically and magnetically neutral, they would pass right though your EM field.

We've actually closer to developing time travel than we are force fields, simply because we know how time travel might work using our understanding of physics.

Colt
2003-Jul-09, 07:15 PM
Copying and pasting from other times I have talked about this..
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I have always thought that the shield system worked with sets of capacitors. When the shields are struck by something it drains part of the charge held in the capacitors for that shield section. When all of the energy from a capacitor/shield set has been drained the shields are "down" and damage is incurred to the hull. This would also help to explain why they can sometimes bring the shields back up once they have been knocked out; they simply reroute energy to the capacitors to charge them.
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Of course that explains how they might operate, not how they work. -Colt

TrAI
2003-Jul-09, 07:50 PM
wedgebert:

Hmmm, well, you could deflect any atoms with a magnetic field, exept those that are para or ferromagnetic, you see, atoms are repulsed by magnetic fields, it is called diamagnetism, this effect is just so small that it is not usualy noted. Even powerful diamagnetics like bismuth or pyrolitic carbon is not that strong, but you can levitate it over a magnet if the magnet is strong enough(There are many sites on the net about "diamagnetic levetation")... A feromagnetic material, iron, cobalt or nickel(and aloys like mumetal) would drop to the magnet like a rock down a black hole(ok, this is of course an exaggeration :wink:)
But this field would have to be extremely strong for it to have any noticable effect..

They have levitated frogs and stuff in powerful magnetic fields, you know...

TrAI
2003-Jul-09, 07:59 PM
According to the "Star Trek Technical Manual" shields use phase modulation repultion technology to block incoming energy. When they incoming is a light phase or particle beam they match the freq. and exceed the power. This is a rather brute force approach. I would have designed them to absorb incoming energy and convert it to matter ala Einstein's E=MC^2, route it through the transporters and make whatever valuable you need. You could get gold, platinum, etc. to any quantity you want without having to divert power from your propulsion system.

Hmmm, how do one detect the phase, frequency and amount of light before it impacts the ship? and this would be an absorbtion(or more accuratly a destructive interference) shield. As i understand it the ships shield a deflective shield, like the navigational deflector only for more powerfull things, it is generated by the deflector shield grid, or something like that, or do i remember incorrectly?...

Humphrey
2003-Jul-09, 08:03 PM
Colt: that also make sense with the "damage" the shields get. The capacitors can only hold a certain amount. So the percentages being stated by the crew is the amount of capacity a capacitor has left in its buffer. Then Blam! the buffers overload and automatic shutdown of the shield.

Humphrey
2003-Jul-09, 08:07 PM
See i thought a real world shield system would use electromagnetic repulsion and atteraction. You would have a dual layer of shielding. One very, very strong layer that is negatively charged, and a second layer behind that that is also negatively charged. (they can also change charges radomly, to throw off any ememies)

The first layer charges an incoming object and the second layer repulses it. The object will then just bounce between the two layers untill all energy is used up.

darkhunter
2003-Jul-09, 09:18 PM
Although given the amount of energy the shield need to deflect for FTL, phasers and photon torpedos should be mosquito bites--interstellar dust hit at that high of speed would pack quite a bit of energy...

Or phasers and torpedo's are capably of removing large chunks of a planet... :o

TinFoilHat
2003-Jul-09, 09:26 PM
Although given the amount of energy the shield need to deflect for FTL, phasers and photon torpedos should be mosquito bites--interstellar dust hit at that high of speed would pack quite a bit of energy...
Maybe, maybe not. It depends on how a ship travelling at FTL speeds interacts with non-FTL matter. After all, trying to use known relatavistif physics equations to calculate the kinetic energy of a particle travelling faster than the speed of light doesn't give useful results.

It may be that particles of dust in the way get accelerated to the same FTL speed as the ship the moment the ship's warp effect touches them, so the actual impact velocity would be small. This would make sense if the warp drive was causing the space the ship is in to move relative to the rest of the universe, rather than moving the ship itself at FTL speeds through normal space, which is a much more plausible explanation for how the warp driev works.

Wingnut Ninja
2003-Jul-09, 09:46 PM
If shields block phaser fire by matching frequencies, how come you can shoot through them if you match the frequency?

It's such an absurd concept I can't even think of a proper analogy. :o

daver
2003-Jul-09, 11:08 PM
Only problem with Sheilds are that they are EXTEMELY bad astonomy (bad physics actually).

With our current understanding of physics, there is no way for us to design any kind of force field. Not now, not 1000 years from now. It's not a matter of technology so much as a matter of there's nothing in physics that would allow for such effects.

We've only got four fundmental forces to work with, three of which are attractive only (Strong, Weak, Gravity). You can use electromagnetic fields to divert charged objects, it's not a "shield". And since most weapons (fictional and real-life) are electrically and magnetically neutral, they would pass right though your EM field.

We've actually closer to developing time travel than we are force fields, simply because we know how time travel might work using our understanding of physics.

Deflectors, tractor beams, ship's gravity probably all work off the same principle, whatever that is. Various things like anti-gravity boots, various levitating planetary transports, and possibly shuttlecraft might work the same way.

Shields seem able to block energy weapons and transporters, and i think can be tuned to block things like radar (from the Gary Seven episode, although they might have been using deflectors for that). If i were trying to make Star Trek consistent, i'd have tractor beams and deflectors based on a longer-range artificial gravity and only affect material objects, and have shields only affect energy-based weapons (transporters, phasers, disrupters, photon torpedos. Maybe photons). I'd never let things transport through shields (the smallest shield could stop the most powerful transporter). Energy weapons could fire out through shields by opening a small hole in the shield for the weapon to fire through. This is dangerous--if that spot of the shield were hit when the weapon was fired, the ship could take damage.

And, i'd take a page from Doc Smith, and make energy weapons enormously more devastating than material weapons. A ship with shields could withstand several phaser broadsides; once the shields go down, the ship goes up in a puff of plasma.

However, that's not the way the Star Trek people chose to do things.

wedgebert
2003-Jul-10, 04:13 AM
wedgebert:

Hmmm, well, you could deflect any atoms with a magnetic field, exept those that are para or ferromagnetic, you see, atoms are repulsed by magnetic fields, it is called diamagnetism, this effect is just so small that it is not usualy noted. Even powerful diamagnetics like bismuth or pyrolitic carbon is not that strong, but you can levitate it over a magnet if the magnet is strong enough(There are many sites on the net about "diamagnetic levetation")... A feromagnetic material, iron, cobalt or nickel(and aloys like mumetal) would drop to the magnet like a rock down a black hole(ok, this is of course an exaggeration :wink:)
But this field would have to be extremely strong for it to have any noticable effect..

They have levitated frogs and stuff in powerful magnetic fields, you know...

Yeah, I know about diamagnetisim, but look at it this way. If you're putting out enough force to deflect incoming weapons, what about the force that's also being directed back at your ship?


See i thought a real world shield system would use electromagnetic repulsion and atteraction. You would have a dual layer of shielding. One very, very strong layer that is negatively charged, and a second layer behind that that is also negatively charged. (they can also change charges radomly, to throw off any ememies)

The first layer charges an incoming object and the second layer repulses it. The object will then just bounce between the two layers untill all energy is used up.

What happens if they fire a spread of weapons, half of which are positively charged, and the other half negatively charged? Half will be deflected while the other half will experience a large acceleration.

I think the only possible way to have shielding would be with some form of gravity manipulation. If you could distort gravity you could alter the paths of incoming weapons.

AstroSmurf
2003-Jul-10, 09:02 AM
Has anyone read "The Physics of Star Trek"? There's bound to at least be a treknobabble explanation of the shields in it.

I always thought the shields used some sort of anti-gravity technology, which is probably what most people think of when talking about "force fields". Star Wars has them too, not that this is a merit or anything...

Another thing about force fields is that they seem to be transparent to light-frequency photons - they aren't even deflected, which is what I'd assume from a strong gravity field. Seems to me that an ordinary laser might be useful.

TrAI
2003-Jul-10, 02:37 PM
Yeah, I know about diamagnetisim, but look at it this way. If you're putting out enough force to deflect incoming weapons, what about the force that's also being directed back at your ship?


Well, hmmm... you could possibly install some magnetic shielding in the craft, the problem would be that that it isn't really any easy way to do that.. you might be able to make something by waffering pyrolitic carbon or bismuth(strong diamagnetics, opposes magnetic fields) and iron(ferromagnetic, shorts magnetic fields) but i don't know what that would result in... probably the ship would have to be designed for the extreme stresses involved.. hehe, it probably is no use trying to understand the shields in sci-fi anyway... :wink:

logicboy
2003-Jul-10, 06:19 PM
This is one way shields might work

What about using light to slow down matter. The Laser Cooling Proccess (http://www.colorado.edu/physics/2000/applets/lcooling1.html) is an example, but it would have to be on a much larger scale to protect a whole ship plus different types of atoms react to different wavelengths.

wedgebert
2003-Jul-10, 06:26 PM
This is one way shields might work

What about using light to slow down matter. The Laser Cooling Proccess (http://www.colorado.edu/physics/2000/applets/lcooling1.html) is an example, but it would have to be on a much larger scale to protect a whole ship plus different types of atoms react to different wavelengths.

But what about deflecting energy weapons?

logicboy
2003-Jul-10, 06:47 PM
Thats just what I was thinking


The only solution I can think of is a GIANT MIRROR :lol:

Russ
2003-Jul-10, 09:44 PM
To: Man On The Moon & TrAI:

I appologize for being obtuse but I really just read the fiction and extrapolate what is possible. Since there is no real physics behind all of this I can only guess at what is possible based on the rules defined for that fictiional universe. In short, I have no explanation for what I wrote. :oops: :roll: :D

captain swoop
2003-Jul-11, 08:00 AM
In Blakes 7 the Liberator could project a Force Wall, it wasn't an 'enveloe' that surrounded the ship, this to my mind wouod be a better use of your energy reserves, why protect thew angles not being attacked?

darkhunter
2003-Jul-11, 06:48 PM
Read a short story one time (think it was by Asimov, but could have been Clarke :oops: --it was 20 + years ago :wink: ) aboout the development of a Force feild.

It was simple the atomic forces that bind atoms together--without the atoms needing to be there...

They kept trying to generate a constant feild and found it really unstable..In the end it worked out it had to "flicker" (with an extremely high frequency--fast enough to be air tight) to actually work. This could be the source of the idea of using phase modulation (considering the technical accuracy of television writers) to shoot energy weopons through.

They were designed to replace the heavy hulls of spacships to allow for more cargo capacity...

wedgebert
2003-Jul-11, 08:12 PM
I'm not sure how a field like that would work. The strong and weak forces (responsible for holding atoms together) are purely attractive and extremely short ranged (I believe the Strong force has the range of a neutron width or something).

daver
2003-Jul-11, 10:09 PM
Read a short story one time (think it was by Asimov, but could have been Clarke :oops: --it was 20 + years ago :wink: ) aboout the development of a Force feild.

It was simple the atomic forces that bind atoms together--without the atoms needing to be there...

They kept trying to generate a constant feild and found it really unstable..In the end it worked out it had to "flicker" (with an extremely high frequency--fast enough to be air tight) to actually work. This could be the source of the idea of using phase modulation (considering the technical accuracy of television writers) to shoot energy weopons through.

They were designed to replace the heavy hulls of spacships to allow for more cargo capacity...

That was by Asimov. There were a couple stories dealing with that concept. In the first one, Jupiter had a solid surface, and the inhabitants of Jupiter turned out to be really really nasty. Fortunately, due to the weaknesses of metals under those pressures, there was no way the Jovians could build space craft and escape their confinement. Unfortunately, force fields weren't subject to chemical limitations. Fortunately, one scientist had just managed to prove that there was a fundamental weakness in force fields that would prevent a stable force field of the required strength from existing. Huge sigh of relief. Until a new ship arrives from earth with a pulsed force field.

Colt
2003-Jul-12, 12:41 AM
ST: TNG Technical Manual, Pg.138, "11.8 Deflector Shields", Par. 2 -

Like most forcefield devices, the deflector system creates a localized zone of highly focused spatial distortion within which an energetic graviton field is maintained. The deflector field itself is emitted and shaped by a series of conformal transmission grids on the spacecraft exterior, resulting in a field that closely follows the form of the vehicle itself. This field is highly resistive to impact due to mechanical incursions ranging from relavistic subatomic particles to more massive objects at lesser relative velocities. When such an intrusion occurs, field energy is concentrated at the point of impact, creating an intense localized spatial distortion.

Well, if you can figure that out then you are a better Trek Techie than I. :o

As some mentioned above, I always thought that realistic forcefields would work on some form of magnetic repulsion or artificial gravity. :-s

BTW, the section on Deflectors/shields is two pages with graphics. If you want me to I can scan some of the drawings and type out more stuff. Just ask and I'll be happy to do it (with correct references of course). Bork. -Colt

Humphrey
2003-Jul-12, 02:09 AM
So tell me if i am undeerstanding this right.:

The hull is magically lined with impossible substances that when hit by a physical substance they create a small instability in our universe, thus sending this particle into some sort of trek limbo.


But then again , i am probobly far off.

[spelling]

wedgebert
2003-Jul-12, 02:31 AM
So tell me if i am undeerstanding this right.:

The hull is magically lined with impossibvle substances that when hit bty a physical substance they create a small instability in our universe, tus sending this particle into some sort of trek limbo.


But then again , i am probobly far off.

Yes, but now with 250% more technobabble!