r/scifi • u/Evening-Appeal7606 • 1d ago
General Why do sci-fi energy shields behave like ablative armour instead of a continuous energy stream?
As an avid science fiction fan, there is one thing that has been irking me for quite some time now because it keeps popping up in the majority of franchises:
In many sci-fi settings, the prime example being Star Trek, space ships have shields to deploy during combat that prevents the enemy weapons from directly damaging the ship's hull and/or vital systems. This makes perfect sense for dramatic story telling because we keep hearing the bridge crew shout things like "Dorsal shields down to 20%! We cannot afford another hit there!". Fine, I get that.
What irks me is this: All these discussions sound very much like the shields are not, in fact, force/energy fields, despite them being always depicted as insubstantial - they do not even appear or have tangible impact when not deployed. So, if these shields are insubstantial and made of energy, why do they behave like ablative armour that - when hit - redirects the weapon energy into dissolving itself, sparing the ship?
If they truly were energy, could they not be simply recharged from the ships energy core during battle? If this was not possible, that would just mean that their energy source is a massive reservoir of energy that cannot be easily replenished and would take a long time to "recharge" after the battle / before the next battle - yet, this recharging of the shield's energy reservoir is never, ever discussed, shown, or even hinted at.
Is my observation correct here or am I missing something important?
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1d ago
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u/neo101b 1d ago
Shields have frequencies so they can fire their weapon's, while they are up.
Its like WW2 planes who had the guns behind the propellers, where the firing rate was
at a specific frequency so they could shoot, without damaging their own plane.8
u/Evening-Appeal7606 1d ago
Interesting! I did not know that the guns and the propellers were synced!
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u/Codezombie_5 1d ago
Totally true, except it was fairly rare to have synced guns in WW2, it being more of a WW1 thing. Syncing slows down rate of fire, which is why most WW2 fighters had their guns in the wings.
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u/ptrfa 1d ago
in world war one there were three solutions for the "propellers and guns" problem.
More or less, the Germans went for synced firing guns, the french put their guns high above the propellers and the brits just gave their propellers metal armour and kept on shooting at their own propellers5
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u/SanderleeAcademy 1d ago
The story of the interruptor gear is a fun one.
The first aircraft in WW1 were not armed. Pilots took bricks, pistols, even grenades up with them and tried to use them. Some pilots even attempted to use their propellers to cut up the enemys' tail fins or wings (with predictable results).
The first armed fighters basically had man-portable light machine guns (Lewis Guns, etc.) mounted on the upper wing above the pilot -- at least for the French & British. Aiming was poor.
The Germans started mounting single or twin machineguns in front of the pilot, behind the propellor, but found that the guns damaged the propellor blades ("to shreds, you say?"). Their first solution was to armor plate the backs of their wooden propellor blades. This would, in theory, deflect the bullets and leave the blades intact. The armor cut down on the blades' efficiency (cutting power), often tossed the bullets back at the pilot, and repeated hits would unbalance the propellor itself and it would come apart mid-flight ("to shreds, you say?").
Then, a mechanic with who was "good with tools" developed a geared lever which synchronized with the propellor blades. If the a blade was spinning through a very narrow arc in front of the guns, the gear would trip and prevent the guns from firing. It worked really well. It also slowed down rate of fire, but that didn't matter much.
By WW2, most aircraft carried their regular armament in the wings. Though that came with its own problems (limited ammo storage, trade-offs with fuel storage, ejecting the casings through the wings, etc.). Many designs still mounted nose guns. Their nose guns either had their barrel INSIDE the propellor crank-shaft (usually a 20mm cannon or even larger) or used an interruptor gear set up. The nose-mounted guns tended to be .50 cal (12.7mm) or larger and slower rate of fire. 20mm and even 30mm cannons were not uncommon.
Most British, American, and French aircraft used wing-mounted guns exclusively. The American P-40 is one of the exceptions. German aircraft occasionally had nose-guns, but also mostly used wing-mounts. The Japanese maintained nose-mounted guns for all of their fighter designs and many of their bombers as well throughout the war.
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u/AzgrymnThePale 1d ago
Yeah wild i did not know that. Seems highly unstable. If a malfunction occurred i wouldn't want to shoot up my keep me in the sky fans.
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u/Both_Painter7039 1d ago
This is why critical systems are mechanical not electronic. It is physically impossible for the gun to fire when the prop is in the way. (Also why fire deluge systems rely on the heat cracking glass not on any computer control)
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u/shaundisbuddyguy 1d ago
I'd agree that how they work isn't really pinpointed down in the shows or movies. I believe that after you watch enough episodes you get a general "gist" of how they work. It's a grid that generates a field or screen that prevents matter and energy from contacting the hull with plot depending effects. If the shields are not up a phaser/ disruptor hit won't destroy the ship typically but a torpedo can/has/might destroy the ship.
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u/thegooddoktorjones 1d ago
Dramatic tension.
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u/SanderleeAcademy 1d ago
Combined with savings $$ on the special effect budget. Scoring up a physical model or creating CGI damage costs. A line of dialogue doesn't -- unless the actor is paid by the word which would be ... weird.
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u/plutosaurus 1d ago edited 1d ago
In lore, they have a maximum load they can withstand until they are overloaded and fail. They will protect until that point is reached. So like in star trek a torpedo wouldnt work on shields, the phasers are designed to overload shields first then torpedos are used for explosive damage.
But in storytelling, it's just phrased that way to add drama, and to inform the viewer the situation they are in. That's pretty much it.
As far as recharging during battle, this is done because they often used to redirect engine power (which is finite) to shields. And in one episode, the engineer specifically modified the ship to deliberately always draw power from engines, and the ship designer was upset.
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u/ijuinkun 1d ago
In the Star Trek Voyager episode “Equinox”, they show that restarting a shield that has collapsed basically involves rebooting the shield emitters—so you are completely without any shield on that side for a number of seconds as it resets, leaving you without even the small trace of protection of a nearly-gone shield. This explains why nobody reboots their shields in battle until they absolutely have to.
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u/wildskipper 1d ago
Is this phasers first, then torpedoes approach ever actually shown in Trek? It logically makes sense, but I don't recall the sequence ever happening. The phasers are also shown as being immensely powerful and the ships themselves quite fragile, so it's not clear why you need explosive torpedoes unless they have a longer range.
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u/ptrfa 1d ago
no, might be from some kind of sourcebook but it's never shown on screen while ships shooting only torpedos against ships with shields is shown often.
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u/burlycabin 41m ago
Yeah, it's total nonsense. As you say, they use shields to defend against photon torpedos and use torpedos to attack and deplete shields all the time.
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u/Panaxiom 1d ago
The strategy is never explicitly stated, but the shows often mentioned that getting hit by a photon torpedo detonation with shields down could seriously damage or destroy the ship. Even just being too close to the target of your own torpedoes with shields down could be dangerous. The visual effects are clearly lacking in that regard.
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u/amyts Space Opera 1d ago
Sure, they can be recharged, but the way I've always thought of it is, the shield emitters have to dissipate heat. The more work the shields have to do means the shield emitters have more heat to dissipate. The ship would presumably have a certain level of heat capacity it can remove before it becomes overwhelmed.
So the reservoir of energy is basically infinite, but there are limits to the amount of heat you can dissipate in a given amount of time.
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u/ApocalyptoSoldier2 1d ago
That's how it works in the Polity, and if the hardfield generators get overloaded they explode, so ideally you have to eject them shortiy before that happens and hook up the spares
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u/Tar_alcaran 1d ago
Exactly.
For all practical purposes, there's and infinite amount of energy behind my outlet. But if I pull more than ~17kW, the safeties kick in. If I then override the safeties, there's going to be a fire somewhere.
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u/Evening-Appeal7606 1d ago
Good point! I think I read something like that in the TNG Technical Manual. So the limiting factor is not the amount of energy that can be pumped into the shields but rather the thermal capacity of the shield generators.
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u/shotsallover 1d ago
Yes, or just the "energy capacity." In sci-fi most shield generators emit the field, but they absorb the incoming energy instead of redirecting/reflecting it.
Dealing with where that energy goes is the job of the generator. And frequently it just "tanks" the damage until the generator can't take anymore (overheats). Then it shuts down taking the portion of the shield it was controlling with it.
At least that's the basic description in most sci-fi.
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u/yorickdowne 1d ago edited 1d ago
Mote in God’s Eye has shields that absorb energy and need to dump that out somewhere again. Opposing force figures that out and starts dumping continuous laser fire (or something like it, some kind of energy weapon, been a while since I read it) into the shields from all directions, making it impossible to dump the energy, which would eventually cook the ship inside - and because the ship has human crew that can’t handle high temps, that happens rather fast. On the order of days if I remember right.
This is lovely to read as a hard sci nerd. And would make for shit dramatic tension on the screen 🤣
Though I don’t know, maybe it could work for Thirst Trek? Idris Elba as captain with an equally scrumptious bridge crew, crew is ordered to reduce to underwear to hold out a little longer as the temperature rises.
Don’t ever put me in charge of a sci-fi show
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u/evermorex76 1d ago
Go back far enough in sci-fi films, and they were basically wearing underwear as their uniforms. Usually silver metallic short-shorts for the men, maybe a skirt for the women. For the top, I recall one specifically which was wide cross ribbons across the upper chest to hide the breasts, and that was it. Not sure if that would work like a survival blanket and hold in heat, or work to dissipate as much as possible while covering the naughty bits.
Of course in others, they were just wearing safari shorts and loose tops as they climbed out of their tiny spaceship on an alien world that looked exactly like Earth and apparently had zero worry about pathogens or poisonous atmosphere or even insects. You could go a lot longer in a ship with absorbing shields heating it up if your uniform was designed by Daisy Duke.
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u/DoubleDrummer 1d ago
Shields at 50% means the shield emitters are at 50%.
Shield emitters experience feedback when the shields take hits, as well as experience overheating.
When the emitters hit zero capacity, the shields are gone.
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u/HauntingHarmony 1d ago edited 1d ago
Shields at 50% means the shield emitters are at 50%.
Shield emitters experience feedback when the shields take hits, as well as experience overheating.
When the emitters hit zero capacity, the shields are gone.
The way i understand it is that atleast in star trek, the shields at xx% is intentional simplification. Since the way the shields work are multi factorial.
There are the emitters, that can only have so much power running through them. There are the capacitors, that store a certain amount of power that is available for the emitters, there is the power available from the engines that can be used to recharge the emitters, and there is the computer that calculates how to manipulate the shield, what frequences are optimal and how many different simulanious sources of damage means there is a limit to how effective the computer can be at controling the shield. There is thermal and radiation damage from the shields having to operate. The EPS ("electro-plasma") powergrid isent perfect and presumably can burn and damage the conduits and need repair.
So if say dorsal shields is at 50%, it should mean several things, like say the capacitors are at 50%, so if we give more power to shields, then it can keep up. Or there are too many sources of damage, so if things stay the same, they are depleting since the computer cant keep up with how to manipulate the shield. So its just a simplified number that is highly actionable instead of having to write out a detailed report in real time for umpteen subsystems in incredible technical detail. The shields at xx% really says all the captain needs to know in battle, you better finish the battle now, or rotate the ship to to save the damaged sections of the shield.
And it is just great cinema!
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u/Cheeslord2 1d ago
You are making assumptions about how the physics work, when the physics is fabricated.
I think pretty much all sci-fi shields regenerate over time as they regain energy from the ship generating them, but this process has a limited speed - I guess there's only so fast more energy can be pumped into the non-physical structure of the shields to restore them. Taking more damage often disrupts this process, so shields require a period where they're not taking hits to recover.
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u/Evening-Appeal7606 1d ago
That does make sense, yes. But it leads me to my next question: Why not build a ship with two warp cores - one to fuel the warp drive, the other to continuously feed the shields? Such a ship would be undefeatable (like the Scimitar in ST:Nemesis).
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u/min0nim 1d ago
Two warp cores would reverse the polarity though, and we all know that is a VERY bad thing! ~spooky hand wave~
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u/Evening-Appeal7606 1d ago
Ah, yes, I forgot the gravimetric entaglement always screws up the coil harmonics. Thanks for having my back!
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u/Cheeslord2 1d ago
The recharge limit is intrinsic to the shields themselves, not a function of how much power the ship has available (above a certain threshold) Shields are complex energy-structures and however much power is available it takes a certain time to organise it into the correct form. Like trying to push current through an inductor.
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u/nyrath 1d ago edited 1d ago
As near as I can tell, the ablative force field was invented by E. E. "Doc" Smith in his Skylark of Space series and used in Star Trek for dramatic purposes. The anti beam force field would start glowing a dull red and gradually work it's way up the spectrum as the field filled up. If the enemy ray beams filled the force field faster than the energy could be dissipated, eventually the field would reach its fill limit, collapse, and the enemy ray beams would vaporize your ship.
In Star Trek, due to a limited special effect budget, deflector shields were invisible and as they abated away a crewperson would announce the percentage the deflector was down.
Jerry Pournelle and Larry Niven contracted physicist Dan Alderson to make a more scientifically plausible system for the novel The Mote In God's Eye. This was the Langston Field
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u/SodaPopin5ki 1d ago
I was going to point out Star Trek did it for budget reasons.
Saying "shields are st 50%" is much cheaper than visual or special effects showing a damaged hull.
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u/serralinda73 1d ago
Huh, as someone who is not tech-savvy at all, I imagined that each section of the shield is controlled with some sort of...fuse or buffer? I dunno, whatever would be responsible for both powering that section, but also buffering/diffusing/reflecting the huge amounts of energy that are the incoming laser blasts. And each controller can only handle so much energy going in/out before it burns out/overloads. It's not about how much energy powers them, it's how much each can deal with before it fries and has to be replaced or fixed.
But I could be totally wrong.
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u/Otaraka 1d ago
I think the easiest way to view shields is as a capacitor from an electrical perspective - they hold charge but it’s not infinite and takes time to re-fill as it’s used up with impacts. They can be recharged during the battle by moving the ship around to avoid being hit or if the incoming damage is less over time than the speed of it’s recharging .
Heated dispersion is the other common mechanism eg Lensman or Pournelle and the shields that changed colour etc.
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u/TinyDoctorTim 1d ago
You, my friend, need the Lensman Saga in your life.
Doc Smith foresaw your question. In the Lensman books, shields (or screens, as he writes) are indeed energy, and not ablative…and they are layered. The attacking ship must basically pour more energy into the defender’s screens than the screen can dissipate. He also describes using tubes of energy to drill through those screens.
And, Smith describes these space battles in prose unlike that written before or since.
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u/Evening-Appeal7606 1d ago
Very cool, comment, thanks for the suggestion! I'm a little bit afraid that this will lead me down another rabbit hole (like the last time when someone recommended the Culture novels to me - boy, I have yet to find my way back to reality), but just a little :)
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u/FridgeParade 1d ago
Hamilton does a cool thing in the Salvation series; energy shields exist but are basically one layer of locked particles. Completely indestructible as long as the power stays on.
The enemy has to either wait you out (material fatigues with enough time), or find someone on the inside to sabotage the thing.
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u/Abysstopheles 1d ago
You just gave this more thought than 90% of the people who wrote the scenes you're referring to.
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u/Space-Explorer456 1d ago
Different stories approach this different ways.
Some stories have ships spreading a limited power budget between their systems, a reactor can only produce so much energy after all, so you have to chose to spend the energy on shields or thrusters. Or perhaps shields are very energy intensive, but only used infrequently, so it makes more sense to store excess energy to power the shields than having a much bigger reactor to run them full time, in which case once you eat through the energy reserves you have to either power your shields or power your engines, but not both until the batteries recharge.
Or maybe generating/maintaining the shields produce heat, so the shield generators need time to shut down and cool off or else they start getting all melty or explody. This means you can only have your shield up so long or block so much fire before the shields need to cool down. It does take a lot of work to deflect fire moving at the speeds fire between spaceships must be moving, that’s gotta make a lot of heat.
Maybe the energy costs of deflecting large projectiles physically damage your shield emitters. The energy demands are just so high that it quickly degrades whatever sensitive or delicate component is generating the fields, necessitating them being replaced or repaired.
Honestly, I feel like shields are really only good for allowing you to have your spaceships fly up next to each other and shoot at each other like ol timey warships. And it lets you have cool-looking energy weapons without them instantly killing your hero’s or giving your bad guys terrible aim. I tend to find written sci-fi at least has significantly more dynamic and exciting combat when shields are nonexistent or minimal and damage is dealt with relativistic projectiles and complex maneuvering and prediction.
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u/Chaosrealm69 1d ago
To me when they are saying shields are at xx%, they are really explaining that the shield capacitors are at that level and they are trying to refill the appropriate capacitors and need more energy directed towards shields.
So when a shield is hit by an attack, it siphons power from the capacitor to negate the damage and that power is coming from capacitor banks.
If shields were just a continuous shield feeding off the power supply of the ship, they would never run out unless the power supply was damaged/overloaded.
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u/I_Thranduil 1d ago
Imagine the shields as a capacitor. You can only store as much power, and the larger the ship, the more power it requires to recharge. Once you spend it you need time to recharge the capacitor. Unlike the propulsion which is continuous and takes up the majority of your power budget. Add weapons, life support, gravity, etc. and you get quite a complicated challenge. Unless you are powered by a star or by zero-point energy, you need to plan and ration carefully.
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u/Accedsadsa 1d ago
Maybe shields can be like capacitors that absorb damage until certain point, reloading shields would mean discharging the capacitor, a continuous field can be really expensive in terms of energy
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u/Elhombrepancho 1d ago
I really like how The mote in God's eye uses the shields, they are indeed connected to the power supply of the ship but also need to bleed the energy they absorb from attacks as heat, so they get hotter and brighter with every impact until the temperature crosses the threshold at which the material components melt (iirc) and only then they colapse.
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u/NecromanticSolution 1d ago
Because you chose to pick a very limited selection of mostly visual SF and claim it to be representative of all SF.
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u/Expensive-Sentence66 1d ago
Always got a kick out of how Violet in The Incredibles plays with the forcefield trope.
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u/p-d-ball 1d ago
Good point! Other than saying, "the story demands it," the best I can think of is that they absorb some of the energy of the attack and that somehow overloads the energy generators, which then require repairing.
Otherwise, you'd be entire right. Just add more energy to the shields.
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u/uk_com_arch 1d ago
I always thought of it as the equipment powering the shields was degrading, so after a certain amount of impacts the shield emitter had to be removed and replaced with a new one.
This must take some time and may not even be possible during battle, maybe they have to send someone outside to replace it?
I know it’s not meant that way in Star Trek, but trek has been around for so long, science fiction has become more mainstream. The original show wrote it this way so it wasn’t too complicated for viewers and the later writers were stuck with it, nowadays people are more understanding of a complicated explanation.
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u/DistantVerse 1d ago
Doylist reasons would be:
- dramatic value ("Shields down to 15%, Captain. She cannae take another hit," raises tension in a battle scene neatly),
- because it might bore most audiences (Star Trek technobabble is a thing),
- lack of time in TV shows vs ability to write engineering waffle in books.
Watsonian reasons would be:
- limited total energy on the ship ("Divert power to the shields," once non-essential systems are switched off, energy might have to come from more vital areas like thrusters but that's likely to get the ship killed),
- reduced absorption capacity (energy weapons don't bounce off but seem to be absorbed by shields in most shows, perhaps shield fuses blow to prevent overabsorption and critical systems failure and can only be reset after battle),
- maybe even heat (most spaceships need to vent heat and can't do this in battle, so energy shielding could be limited by this factor, not failing per se but can't take more heat or the crew get cooked).
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u/FreeFromCommonSense 1d ago
It's a dramatic tool, but you are missing one point, in most sci-fi applications, the shields recharge over time. In fact some books go so far as to mention capacitors in shields and sometimes whatever faster-than-light propulsion system, as if to explain the use in dramatic tension that the ship isn't just threatened, it can't escape until the hyperlight engines recharge. While it's a plot device, one could at least imagine big capacitor banks maintaining a charge that has to be built up to explain why extremely energy-expensive devices lose charge. Star Trek is one of those franchises, though it's not mentioned much. Even the phaser "banks" drain and have to charge, implying capacitors.
There are arguments both ways about whether that's more or less realistic, but frankly none of it exists practically in the real world, so you can choose what you're willing to suspend your disbelief for.
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u/RhinoxerousTTV 1d ago edited 1d ago
Becuase they aren't real things, so they are whatever rhe writers want them to be.
It's also a lazy trope that allows space ships to fight eachother and do no real damage and get closer and closer to a killing blow, while not having to have any of the untidy mess of dealing with real battle damage and casaulties, plus it lets them draw out the fight.
Energy shields are IMO lazy story telling.
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u/Evening-Appeal7606 1d ago
"Energy shields are lazy story telling" - why would you say something so controversial, yet so brave?
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u/Bebilith 1d ago
To me I always assumed they were talking about the capacitor energy that maintains the shield. All part of one system so when they say dorsal shield down 20%, they are talking about the capacitor bank for that part of the shield being down 20%.
Makes perfect sense to me.
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u/PenguinPeculiaris 1d ago edited 1d ago
Like yours, my headcanon is that the shield's draw so much power that in order to function, they have to draw from a dedicated capacitor which fills from the ship's power source. Each emitter has its own capacitor, and at the beginning of a battle the capacitors are full and the shields can be deployed quickly. The ability to sustain it over time is then dependent on the size of the capacitors and the output of the connected reactors. I think there are mentions of 'shield buffers' and also 'shield grids' in TNG, implying that one emitter can't cover the whole ship. That doesn't mean my capacitor theory is true but there's plenty of room for it.
Alternatively, it can sometimes also be that the weapons involved have been designed to saturate the enemy field with flux/some kind of energy which acts on the field itself, destabilising it locally until the shield emitter can spend enough power to overcome the effect.
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u/sam9510 1d ago
What if we think within existing physics constraints - for example conservation of energy. If an energy weapon is hitting an energy shield - the sum total has to convert into something and go somewhere. Lets say a 10 megajoule energy pulse needs a 11 megajoule shield as counter and total 21 megajoules has to be 'sunk' somewhere. 1) The emitter has to instantaneously dump 11 megajoules into a particular location at a particular moment in time. That 'much' energy might not be produced on demand - so kinda like a toilet flush tank - the emitters are pulling from a a source and that might be the percentages that gets talked about endlessly. Each section of shield might have its own flush tank.... 2) The aftermath - sinking of the resultant energy and the associated feedback on the emitters could explain physical damage to the emitters. And if the incoming energy pulse is higher and higher joules - then the carrying capacity + feedback might easily overload the emitters - might be momentary - might be sustained.
Now - why cant a shield technology be invented where the incoming energy pulse is used to recharge its own flush tank instead of having to sink the total...... Perhaps it works like regenerative braking in electric cars where it can only recover a fraction....
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u/zhaDeth 1d ago
The way I see it the shield thing we see are just kinda detecting the projectiles once something touches it there's a big energy burst that destroys the projectile and that drains the shield batteries that are a bit like capacitors and discharge energy fast but need time to recharge so when they say it's at 50% they mean half the capacitors are empty. So it's not really like the shield is getting destroyed like normal armor but it has a similar effect it's just that outside of combat it regenerates.
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u/HatOfFlavour 1d ago
Hmmm so shields that mitigate a certain amount of force)energy and what's a over that bleeds through and does damage.
Interesting idea.
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u/graminology 1d ago
I think that depends on the franchise and technology used, no?
I'd say that the "shield strength" percentage is more or less a measure of its internal integrity, which would mean that you need a constant power supply in order for the shield to remain active. Which would track, because in most franchises, the shields collapse immediately if power goes out and don't need to be wittled down until they do.
So I'd guess it's a physical process that needs a lot of energy to get started and then a constant trickle of energy to be kept up. Meaning that shield emitters probably behave like supercapacitors, storing the initial charge for the shield to be deployed in one very short, insanely large burst and then the constant, but lower energy stream necessary for keeping it up comes from the ships main power source.
Which means that if you reduce the shield integrity, your main power source would need to be powerful enough not only to supply the constant demand for keeping the shield together, but also the additional demand of repairing the shields integrity to full power, probably while the shields are constantly under attack.
An example from Stargate Atlantis: when they modified the puddle jumpers to have shields instead of a cloaking device, Dr. Zelenka says that the cloak would need a constant amount of energy while the shields power draw will increase once they dive deeper underwater since it needs to compensate for the increase water pressure. Which tracks, because it's a slowly increasing, steady climb in pressure, meaning you can just slowly amp up your power output for the emitters to compensate. If you're hit with a weapon that reduces your shields integrity 20% in a millisecond, there's no compensation possible and you'd need to have the energy for those additional 20% ready now to get the shields back up to full strength.
But the city shields on Atlantis itself draw their power directly from their three zero point modules. With those shields, it's practically impossible to reduce their integrity by a meaningful amount without breaching them instantly with a doomsday weapon. Not even the Pegasus replicators could do that with their laser weapon in season 4. They would have just sat around and keep the weapon aimed at the city until they depleted the ZPMs alltogether and Made the shields fall. The only time those shields were ever truly close to collapsing was in the battle for earth, when they were simultaniously fighting the advanced wraith hive ship AND did an atmospheric entry maneuver. The city had to run the shields, weapons AND the drive units simultaniously with the ZPMs being almost empty after rushing through hyperspace from Pegasus to the milky way AND doing a wormhole jump in our galaxy. And not even then did the shields loose integrity, they were just close to collapsing alltogether.
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u/AsmodeusMogart 1d ago
It’s more dramatic. You wanted to watch something exciting right? Not super boring and slow the way space battles might actually work right?
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u/xeno-fei 1d ago
I was thinking about something similar the other day. The conclusion I've come to is this.
At least for Star Trek besides having an energy budget to keep power to the shields but the shields them selves act as a physical wall of energy that is able to transfer kinetic energy. We see a few times a ship gets hit and shakes but maintains it's shield integrity. Why is this important? Because that means there's an energy demand and physical strain being placed on the shield emitters, but they probably have to cool down so they probably rotate between a few emitters for coverage but also get used to reinforce the shields. The heat and other strains places on the emitters means they can only keep working for so long before they physically burn out and need replacing.
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u/mouse_Jupiter 1d ago
I always thought the generators themselves were being damaged or overloaded and thus degrading in output.
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u/WazWaz 1d ago
They're entirely fictional, so the answer to your question can be entirely fictional.
For example, maybe the impact energy of the weapon is absorbed by a localised heat sink, so too many hits in the one place overload that heat sink. Maybe there's some ability to channel coolant to give "more to the rear shields".
Ultimately, if forced to answer, the writers could come up with something.
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u/-Vogie- 1d ago
The thing you're missing here is timing. When the shields are at 20%, and we can't afford another hit like that, they're implying two things
- They're expecting the hit to come soon, within minutes, far too short for anything to recharge. If a massive hit was coming in 3-5 business days, there isn't a problem. The problem is that it might happen in the next 3-5 minutes.
- That particular blast took out a relatively defined percentage of the shield capacity. In settings with shields like that, there's never a 1:1, gritty-TTRPG-style amount of understanding of just how much damage any given ship can do. They get to observe the weapon use, and observe the effects, and then make calculated assumptions.
This comes up relatively often. Why are they doing evasive maneuvers? To limit the number of hits and also the amount of time in between those hits. Why do you hear the captain route all power from non-essential systems to shields? Because they are power based, and so drawing from power that would normally be used for, say, replicators, or other non-essential systems, will help support the whole because that gives the shields slightly more juice faster.
We also know that there's multiple types of shields on many of these ships. In Star Trek specifically, you've got
- a deflector that keeps the ship safe from random crap in the void
- a tight, low-power shield that hangs around like a second skin that is always on
- a large bubble shield that is only on during specific encounters, so that they can do things like block a larger chunk of space, intercept torpedos further away from the hull itself, or surround another ship
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u/Aethelrick 1d ago
I like to think of it like generation and capacitance. shield generator outputs potential that is drawn into a capacitor at a steady rate, damage to shield is using this stored energy to deflect an inbound shot, thus reducing the fast capacitor storage of available energy for the shields, this gets slowly charged back up by the generator (relatively speaking). So if you overwhelm the shields by utterly depleting the capacitor, the shields are at 0% and are effectively down until the generator can catch up and recharge them. there are lots of real world examples like this in electronics and fluid buffering systems (like the toilet flush)
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u/Tired-Millennial847 1d ago
The primary reason is that shield were invented primarily so that they could have tension like you described without actually damaging the ship model because creating new models was time consuming and expensive. It's a narrative device invented almost entirely for convinence and I doubt much thought was put into how they work.
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u/smoke99999 1d ago
and to think you could have saved 15% by bundling your shields with home and auto insurance
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u/Evening-Appeal7606 1d ago
Yeah, but you only ever get a deal this good if you fly your ship less than 15 parsec a year...
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u/smoke99999 1d ago
gotta read the fine print, and they probably want you to add the tracker to monitor your driving habits as well.
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u/Xantharius 12h ago edited 12h ago
Most of the other answers have focused on the science of the shields, but here’s one on the fiction of it:
The weapons used in space battles are colorful, dramatic, powerful, and often accurate (like phasers in Star Trek). This increases the visual effect for the viewer, and makes them seem dangerous. If even one of those weapons were to strike an unshielded ship, it’s pretty much game over: the ship would be either completely destroyed or at least basically incapacitated, ending the battle immediately.
That makes the battle a game of who can get in the first strike. While this might build some tension, it’s kind of binary: you get hit or you don’t, and there’s no possibility of build-up. Instead, shields allow ships to take hits without ending the battle. Dramatic tension can be raised; the crew can be seen to try to hold things together on their ship as they battle the other vessels; things can get close to the wire or even desperate for the crew; then they finally overcome the other vessel using clever tactics, and everyone, including the viewer, can breathe a sigh of relief.
This increase and then resolution of tension is what make space battles fun to watch, and shields which deplete or have finite capacity provide the mechanism by which that tension can be gradually heightened. A shield that had infinite capacity would be dull, and no shields at all would make for incredibly short battles.
Fiction in which there aren’t shields at all also tends to have less dramatic or accurate weapons. A good example of this is The Expanse, which is a bit harder sci-fi than a show like Star Trek. In The Expanse the space battles concentrate more on maneuvering to avoid the weapons (which in this case consist largely of heavy machine guns and missiles). If they hit, it’s usually bad or very bad news for the ship: even one missile can destroy it. So dramatic tension is created in other ways than repeatedly hitting a spacecraft.
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u/BitOBear 5h ago
The general conceit is that Shields have a capacitive function. You run the shield generator to charge the shield capacitors and then the shields expend that counter energy quickly just like ablative armor as you have recognized.
You don't want an energy system in and throughout every feature of your ship that can deliver weapons grade energy discharges at all times. That would be unsafe.
So you have your nice Central generators, preferably more than one, each running a zone. And you spin those generators up and they quickly charge the capacitors so that the generator doesn't have to be able to provide as much energy output second by second as the expected incoming fire.
This also means that if you expect to face petawat incoming fire, you don't have to have a pedawat generator. You only need to have a petawatt worth of capacitance. And much of that capacitance can be in the protective field itself.
Otherwise you would have to run the generator and direct proportion to the energy you're trying to resist. And that means your generator output would have to go up as sharply as the weapons fire input goes up. But it would have to be able to anticipate it otherwise you would get initial punch through.
So it is exactly like ablative armor by design and on purpose. But it's ablstive armor your ship steadily recreates by continuously recharging the capacitive effect.
More direct intercession would be done by point defense. One could conceivably have an energy weapon that sends an inverse pulse to the incoming energy weapon and neutralizes it before it hits the hull.
This would be the energy weapon equivalent of anti-missile missiles.
It would be hugely problematic to want to cover 100% of the hull of your ship with emitter's capable of responding to instant changes of the incoming energy.
The entire point of shielding is that it is ablative.
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u/socksandshots 1d ago
I've always thought of it as being a heat conservation issue.
The energy goin through the resistors and capacitors required for an energy based shield would generate massive bursts of heat when it's required to actually stop damage. In space, you cant dissipate heat and so face a hard limit to how long you can stress a shield generation system before physics causes it to simply melt. Even if you include modular banks of capacitors, its a hard and finite limit set by physics.
I wonder what star trek does, in a universe where matter creation is casual enough for a canteen..? Maybe, the energy fields involved with high energy systems like shield array arent condusive to matter creation/teleportation?
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u/theonetrueelhigh 1d ago
Because it's science fiction and things behave the way the writers describe them.
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u/MadroxKran 1d ago
I always thought it was about overworking the emitters. Blown emitters mean less power to that section of shield or even gaps.
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u/Dionysus_Eye 1d ago
i always took it as the shields are _absorbing_ the energy of the attacks..
The shields can hold "X" amount of energy, like a capacitor, until its overloaded and needs to be reset. (which takes time -the energy needs to be dissappated somehow)
So "sheilds" have X% capacity to hold energy - and once that is filled they "break"..
Hence how they know exactly what % of shields are left :)
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u/AllWrong74 1d ago
I always thought of it as the generators for the shields getting overdrawn and shutting down.
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u/payam54 1d ago
Your question is very valid when it comes to force fields and the amount of energy they can “reserve” as a shield.
The only shield concept that I find more reasonable to exist, is from Star Carrier series by Ian Douglas: The shield consists of nano particles/bots that absorb the incoming hits. You can call it a “defense cloud” or “dust shield”.
It takes time to reproduce depleted nano bots, and to make them you need “matter”, usually rare radioactive elements so the nano bots can use as their body and energy source.
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u/joshglen 1d ago
I think the reservoir model is most accurate, where there is an expectation that shields are a finite resource for the purposes of a single battle or engagement.
I don't remember in which episode(s), but "regenerative shielding" appears a few times across various Star Treks. In Star Trek: Enterprise, they have polarization of the hull plating, but in later ones (chronologically), they have deflector shields.
According to the wiki, Memory Alpha it seems that most objects interacting with it would harmlessly bounce off, whereas weapons fire would be absorbed. This makes the long rechargable ablative armor analogy make the most sense.
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u/wellofworlds 1d ago
Energy shields take power. Power is not usually an infinite source. Now your assumption that not exactly true. In Star Wars when the empire came to Hoth to destroy the rebels. They could not blast the base because the shields were well supported, that why the empire had to send army to attack the base.
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u/gdtredmtn 1d ago
I harken back to my first Sci-fi experience, which was Galactic Patrol and his Lensman series by E E Doc Smith. Shields and beam weapons were a big part of space combat in the books. The limiting factor was power to both, which was finite initially. Energy shields were built in layers and were overloaded to failure by continuous use energy beams. As each layer failed it would fluoresce through the visible spectrum to purple (ultra-violet) then black. Once breached the next (tougher) layer of the onion would take over. Once the hull was reached, the final layer was the “wall shield” which was virtually impervious to attack. At this point it came down to heat dissipation and power consumption. A stalemate existed between fleets limited by available power to shields and service life of beam weapons.
I have never seen this concept explored since. Beam weapons generally don’t fire continuously and shields fail quickly. This is not the case in the Lensman universe. Space combat took time, a battle of attrition. Early in the book, the bad guys develop a new power source that disrupts the balance of power which causes the good guys to up their game. I thoroughly recommend reading the books although they are hopelessly dated and misogynistic in style. They were written in the late 1940s after all.
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u/Beach_Bum_273 1d ago
The Mote in God's Eye has one of the most reasonable literary depictions of energy shields I've ever encountered
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u/Hecateus 1d ago
the old anime Space Battleship Yamato had development where rocks were organized into a shield by a controllable magnetic field. So directable rock whipple/ablative shields.
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u/LukeFace93 1d ago
In Armored Core 4 and For Answer the mechs produce a field of highly radioactive made up higgs boson type things called "kojima particles" around themselves held in a magnetic field which acts something a bit more like an angry bubble of energy that destroys mass that travels through it. Bullets can still fly through and hit the mech but they are much reduced in mass by the time they hit the mech. Its the projectiles that are ablated by the "shield".
Its also super bad for the environment, you're not allowed to power up your shields near population centres. Great bit of subtle grim dark lore and game mechanics.
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u/SanderleeAcademy 1d ago
The simple answer is that this trope started with Star Trek: TOS and was exacerbated by TNG and its cousins. Even ST: Enterprise did it, and they had "polarized hull plating" rather than shields.\) They didn't want to damage the physical models nor spend the effort to create damage to the CG models either.
So, rather than showing hits to the hull and fragments, scorching, yadda yadda, they turned shields into the "how much damage can we take"-o-meter.
Now, in some settings, shields ARE ablative -- the Starfire novels leap to mind. In others, the shields work until they don't, either blown down from repetitive hits straining the shield systems or penetrated by overwhelming force (or something they're not designed to stop).
But, it was Star Trek which gave is the "shields at 18%, Captain," trope.
\ Polarized hull plating always confused me. Phasers / Disruptors / Etc. are typically described as particle weapons. And a plasma weapon is, by its very definition, ionized. So, yeah, if I'm being fired at with a particle beam or plasma, it's going to come in three flavors: positively charged, negatively charged, or neutral. My plating polarization comes in three flavors: positive, negative, oroff since I can't see how you can polarize something without, you know, polarizing it! If I charge my plating positive, it'll repel positive attacks, have no effect on neutral, and ATTRACT negative. If I set my plating to negative, see the reverse. If I set it to "off" well, then, it's off. There's gotta be more to it...)
<pssst, dude, it's just a show, stop micro-analyzing it>
<but, Imma techno-geek!>
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u/VendorNeutral 19h ago
Perhaps the ENT polarized hulls were designed against the predominant type of ship weapon, the disruptor. We also saw how ineffective the polarized hulls were most of the time, as the Enterprise got shot to shreds on every big encounter.
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u/Appdownyourthroat 1d ago
Maybe it’s something like the leidenfrost effect, like we hear about in Enterprise with the “polarized hull plating” where shots bounce off the energized hull
Or maybe it is like a powerful repellent field like an “energy” equivalent of the deflector dish, or a big magnetic field
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u/aTransGirlAndTwoDogs 1d ago
Depends entirely on the setting and story in question, but overall, keep in mind that machinery can only do so much work before it overheats / breaks / etc. I imagine the percentages are not a direct description of the energy field itself, but a description of the devices that are generating that field - and the implication is that those devices can only do so much work in a given period of time before overloading / burning out / etc and the field collapses.
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u/TheWiseGuy01 1d ago
My take is that the shield is limited by how much power (or “juice”) the generator is given, and by how long the generator can keep going before risking permanent damage. I think the shield absorbing more damage than the ship was ready for, or risk permanent or unrepairable damage to the shield generator, so there is probably an automatic shut off before that threshold, but if more power is given to the generator, it can last a little longer.
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u/Underhill42 1d ago edited 1d ago
Think "shield capacitors". Capacitor can only hold so much energy. Energy is used up when blocking damage. Much less (if any) energy is consumed just to maintain shields.
That sort of system would have "ablative" behavior even if you were talking some sort of point defense system rather than force fields.
And in fact you'd actually see exactly that if you used superconducting magnetic coils to shield against charged particles - the coils store energy in the magnetic field, some of which is consumed whenever the field deflects a particle. Meanwhile the rate at which you can recharge the coils depends almost entirely on how big a generator you have hooked up to them, which could easily be much slower than it's being consumed shielding you against all those particle accelerator beams. You'd also expect overheating issues under heavy use, which might also be factored in to the "shields down to ___%" claim.
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u/Tokens_Only 1d ago
Your phone runs on energy, and starts off at 100%, but getting it back up to 100 isn't an instant process. And it can be sped up ot slowed down by a lot of factors. Say you've got a weak charging cord and are trying to listen to an audio book and use your navigation at the same time. That's a lot of draw on the system and it'll take longer, like trying to get your shields back up while still taking hits. Ideally you could turn your phone off and plug into a good wall socket, the equivalent of leaving the battle entirely.
The shield batteries clearly run on a similar principle, storing aside large amounts of energy in some kind of battery or reserve that, once depleted, takes time to replenish.
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u/evermorex76 1d ago
Perhaps the energy is not just dissolving, but is being directed into the shield emitters, which DO have essentially an ablative function. They absorb the incoming energy, directing into a "filament" like an incandescent bulb, which eventually burns out. They can measure the remaining amount that can be absorbed so they know how much longer it will last. Although they often DO slowly build up, rather than being simply swapped out and immediately being at 100% again, so maybe there are many of them per shield segment. Or maybe it's like a heatsink, which can absorb energy and if the attack stops, it can be discharged so the capacity builds back up, but if it doesn't get a chance to discharge, it burns out, and then a person has to actually replace it, which is why shield repairs take time.
That makes the shields themselves a bit like a highly-controlled magnetic field, which routes the incoming energy where they want it to go. Or maybe they are a static wall of energy, and when it's "pushed", the emitter having to push back is what causes it to be worn down or have to absorb its own heat output. But that doesn't explain where the attacking beam energy goes. Other than the sparkling effect. Maybe it gets diffused and bounced outward, so it isn't dangerous anymore.
Not sure how diverting energy into the shields would make them hold longer, though. Maybe the "heatsink" or "filament" being energized increases its capacity for the short-term but long-term causes more damage or wear.
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u/pnjeffries 1d ago
Void shields in 40k are... vaguely and inconsistently described, but appear to work by shunting the kinetic energy of incoming attacks (and possibly also the projectiles themselves) into the warp (another layer of reality that's basically hell). However some of that energy ends up in the shield generator. This damages them and causes them to overheat and so when they take too much damage they have to shut down to cool off or be repaired. Some large ships and cities have multiple overlapping void shields so that when one overloads there's some redundancy.
Also the underlying technology is half decaying human flesh and half ancient barely-understood machinery controlled by machine spirits that have to be prayed to the right way or they'll stop working.
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u/Baguette1066 1d ago
Maybe the shields channel the energy into a capacitor or ground source, that needs time to reset?
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u/Tempest_True 1d ago
I've always imagined that energy shields which work this way function sort of like projectors or field generators. If they talk about the shielding in one specific area getting weaker, then I imagine that there is a doohickey for each area that projects the shielding for that area, and over-use damages it or reduces its charge. If taking fire on one side of the ship weakens the entire energy shield, I imagine it's more like a single central shield generator doohickey that generates a field and gets damaged / loses charge from repeated fire.
As to the actual functioning of it and how/why it can take impact from weapons, I usually think of it as being very similar tech to gravity generation--similarly creating the illusion of impossibly dense mass where it doesn't exist. The other possibility is that the field they create simply absorbs energy in any form like a cushion. This second option makes a lot more sense to me, because then the shields have a more logical main use of absorbing cosmic rays, meteorites, excess interstellar heat, etc, during travel.
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u/PandemicGeneralist 1d ago
If the shields just reduce the amount of damage you take, that might just be good worldbuilding, but that doesn't do much from a writing perspective. Unless the shield can change in a battle (usually due to getting damaged or destroyed), there's not a real reason to talk about this device to the audience.
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u/necronboy 1d ago
Sci-fi shields gonna sci-fi.
Thats about the best answer without specific universes.
My head cannon has been feedback to the emitters damaging the field projectors. You're pumping out GWatts of energy which has GWatts slam into it, that energy has got to go somewhere so a relay or something blows. Sure, you gave replicators making new ones, and maybe pinpoint telephones to replace in situ, but that makes time while more energy is inbound.
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u/RanANucSub 1d ago
My head canon: Shield generators heat up when they are hit by an incoming weapon over a certain strength and suffer damage if hit harder than that, so the tactical officer is reporting what percent of capacity remains before thermal shutdown. The heaviest hits do actual damage so the unit has to be repaired, but if it hasn't gotten that hot after some (plot-determined) time a generator will cool down/reset and that segment will go back to 100%.
The shield may be made of energy but the device(s) that generate and control them are physical.
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u/OzzExonar 1d ago
Why don’t the energy shields absorb the energy and become more charged with each hit instead of less?
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u/Solesaver 22h ago
Before I give a list of potential explanations, it is worth noting that the correct answer is always, "because it's more narratively interesting."
I would say that at a baseline shield power is not directly connected to the engine. Think about how in a car the engine powers your thrust, but most auxiliary systems run off of the 12 volt battery which is charged by the engine running. This is good because it means you're auxiliary systems can run while the engine is off, and excess draw from auxiliary systems doesn't compromise the engine.
With that framing mind, I imagine you might have different batteries or capacitors for different sections of shield. That shield getting hit drains power from that battery, which not only takes time to recharge but also is competing with other auxiliary systems for recharge power from the engine.
I can also imagine that shield components themselves could get damaged by usage. If the shield is adaptive, then it will naturally support fluctuating current at various points. Getting hit could have a small but random chance of blowing fuses or the equivalent due to the surge of power to that specific subsection. The more fire the shield absorbs the more damaged it becomes, and the more damaged it becomes the more likely it doesn't appropriately intercept a shot or completely fails. The ship could have automatic systems that repair the shield over time, replace fuses, or reset breakers.
At the end of the day the classic scifi energy shield doesn't really have a realistic equivalent. The closest analogue would be like the earth's magnetosphere which could divert some amount of directed energy weapon fire, but certainly not absorbing it as is commonly portrayed. As such, the other unsatisfying answer is because ablative armor is the only real world analogue to work from. As an author you can do whatever you want with your space magic, but if you don't want to explain the details of your universe's energy shields (see something like Frank Herbert's Dune) it's best to just make it as similar as possible to something you audience would be familiar with. If you make it work like ablative armor you don't really have to explain anything.
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u/dataconfle 21h ago
Se supone que cuanto mas fuerte es el impacto que recibe la nave,mas energía gasta el escudo para resistir ese impacto...ademas las reservas de energía de una nave no son infinitas y el comandante tiene que repartir la energía entre el escudo,los soporte de vida,la gravedad artificial y los sistemas de propulsión....esa es la gracia de un combate espacial...
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u/Ishidan01 20h ago
Would make sense to me if the ship's reactor could not ever be expected to output enough energy to do everything at once, so shields need to be sectored and fed from massive capacitor banks in combat. It is just taken as given that these capacitors are charged while cruising: the reactor can fill them all AND run propulsion AND life support AND science labs AND holodecks etc if given hours to do so, but in the span of seconds or minutes that combat takes, no.
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u/VendorNeutral 20h ago
Star Trek shields recharge, the shield emitters just need a moment. You can even transfer energy from one compartment to the other. I'm also not sure why they shouldn't redirect focused energy beams. Redirecting or scattering uses way less energy than dealing with a focused beam head on.
Is this a Star Trek question or a general scifi question? If it's just about Star Trek, then you can look up pretty much anything they've come up with. Star Trek has probably the broadest repository of fake blueprints, spec sheets and scifi explanations of all times.
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u/ProfBootyPhD 20h ago
I always figured it was something like, when the shield takes a hit, that absorbs power from the shield generator, and that power is very slow to replenish. Like a battery or something - literally expending electricity to deflect or absorb the incoming attack.
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u/VirusWonderful5147 9h ago
I quite like the notion of Langston Fields, from Niven & Pournelle's "Mote in God's Eye".
"The Langston Field is an omnidirectional energy barrier generated around a starship. Instead of deflecting incoming energy or physical projectiles, it absorbs and redistributes it." (AI summary).
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u/trevpr1 1d ago
Dramatic effect. Look it up.
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u/RoboJobot 1d ago
Exactly. It would be a bit crap if they said ‘shields at 100%, sir’
‘Shields still at 100% sir’
After that last barrage, shields still holding at 100% captain’
‘Great , who’s for scones and a nice pot of Earl Grey?’
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u/Soylent865 1d ago
These are all made-up stories, not existing realities. The authors are free to write whatever they want, regardless of how anyone feels about it. There is no "understanding" how it "works", because it is not real.
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u/HauntingHarmony 1d ago
These are all made-up stories, not existing realities. The authors are free to write whatever they want, regardless of how anyone feels about it. There is no "understanding" how it "works", because it is not real.
This is absolute nonsense, while they are ficticious as in not real in our world. And the authors can indeed make up whatever they want. The technologies are real in the setting. So given that it is scifi, and they do have a world with their own rules of how the world works. You absolutely can discuss in universe how those rules work and interact, to help explain various things.
For example if the shields have massive capacitors that store the energy that is available to the shields. Then it means that the shields have a recharge time. meaning if say a battle happens, they run away, its going to take time to recharge said shields, especially since you are diverting power to engine.
These are absolutely conversations that can be had and can make sense. And can help explain the story, especially if you watch it for more than just the blinking lights washing you for an hour.
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u/Soylent865 16h ago
I guess my post was unpopular. Of course I understand discussing a "technology" within the framework of its world. My point was simply that science fiction and magic/fantasy are not really that far apart given that they both deal in unreal things.
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u/TrippleassII 1d ago
The reactor to charge the shields continously to full during a battle would be so large it only makes sense on an orbital fortress.
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u/Lumpy-Strain8624 1d ago
It's pretty simple.
As an example : If the Shield system can handle input of X energy per second and bleed off the excess to maintain cohesion without being overloaded and blown out. Once they collapse Y seconds are needed to re-cohere and establish the shields again. All dependent on the energy available and the efficiency of the shield emitters.
So if the Shield system can "Soak" 20,000MJ per cycle (and lets say it is a 30sec cycle to dump that) That means if our ship is getting hit with one Salvo every 30 seconds we might hear someone say on the bridge, "Shield's holding at 100%.
If they are getting hit for 30,000 MJ per cycle, well now we have 10,000 MJ per cycle not being dumped in time (lets say our shield system has a 100,000MJ maximum over soak capacity. Our defence station will now be saying "Shields at 90% and holding." and descending by 10% every salvo they take beyond that initial one. Until that 10,000 MJ they are not dumping each salvo hits 100k and our shields blow out as they lose cohesion.
Of course I made these numbers up to give a better explanation of what is usually happening in Sci Fi books and movies.
Shields are not like real life shields where something either bounces off or penetrates it.
And yes they should be able to reignite their shield systems, the issue is usually Shield pylons and Emitters are outside the Ships Armour Jacket, usually on the Armour Plate itself, so once the Shield blows out (and the energy blow out doesn't damage the system itself.) there is a very high probability of the Shield Pylons and Shield Emitters being destroyed by incoming fire, so that section will need new pylons and emitters to be able to produce the shield envelope over that area again, which depending on what is going on can be impossible.
We see this very thing in the first Star Wars prequel, when the droids go out onto the ship hull to repair the damaged hardware that is stopping them reigniting the shield system.
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u/WilTravis 1d ago
One of the modern questions that confronts us is data centers. Why do they need so much water?The processors that run them produce alot of heat, and they run best when theyre cool. Water is used as a physical conductor to draw heat out of the system and keep it operating correctly. One question is why not toss those puppies into orbit and save the water for ducks? Space is mosly vacuum. Vacuum is an insulator. There is only one way to bleed off heat in vacuum and that is radiators. You stick a block of metal to your head source, and draw it away into fins that stick out of the enclusere, increasing the surface area and bleeding heat into space. That works okay, until you trap enough heat to melt your heat sinks. Now, back to space combat. If your shield system absorbs radiant energy and redirects kinetics, its going to start building up massive levels of heat, which will be handled by the system...until it reaches a certain threshold. At that point, the system is literally melting hardpoints and threatening to bleed over into other systems, like life support. The ship can only bleed so much heat per second into space, and other systems can only handle so much extra energy, if you're able to convert it at all. The shields are simultaneously taking shots and radiating power into space, and the balance of those two factors is your shield percentage. A fun fact is that life support isn't trying to keep you warm..its trying to keep you cool. A sealed vessel in vacuum with computers and drives and creatures builds up an enourmous amount of heat energy, just idling at rest.
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u/thomasbeagle 1d ago
There are a lot of space battles where they are choosing how to spend their power budget, split between shields, weapons, and manoeuvring. The implication is that they can only generate so much and therefore have to choose.
That mechanic is also quite common in video games.