How dangerous is someone who can make volumes of air act like immovable solids, measured by how expensive an army they could defeat?

Given a woman who can make volumes of air into solid, impenetrable barriers, how expensive of a modern military force could such a person defeat if her power has these conditions:

• Her effect is basically forcing the air molecules / atoms / ions / whatever, to not move. So she can't filter air or anything.
• "Air" being a shorthand for any gas.
• The altered volumes of air stay where they're placed, relative to the Earth.
• The altered volumes have no visible changes, but only visible light can pass through or affect the volumes.
• When she decides to create a volume, it has to be in her sight, so if her vision is hindered, it's a bit harder, and it doesn't work in the dark.
• Created volumes can be instantaneously expand and shrunk, regardless of vision, in any direction she wishes, so long as they follow the other constraints, and is expanding into open air. If it would fail, she could still try, and will know if it fails, but doesn't know more than it failing because of intersecting an object.
• She can maintain her volumes indefinitely, even through sleeping, but not if rendered unconscious through sleeping gas or other methods.
• The total volume altered must be no larger than 10m³, otherwise, she has to revert some areas to keep her changed volumes, under that limit.
• Any individual section has a thickness of at least 1mm.
• Anything hitting the "forcefield" has no effect. It's just magically stopped, you can't strain her by hitting the field too much, it doesn't turn all kinetic energy into visible light, nothing, just stopped.

The forces are surprised by each other, with the military force initially thinking she's a normal human, and hopefully, they figure out that she's making the barriers.

Inexplicably, hostilities start in the morning, on an open, grassy plain, in calm weather. Behind each party are mountains.

She has no allies.

Hostilities stop once one side is dead or incapacitated.

The forces start one mile apart.

The superpowered woman can use weaponry they acquire from defeating the forces against her.

Technology is constrained to that which is available to 2016 America.

So, how expensive must that army be, in order to defeat a woman with such powers?

Expense is calculated in the cost of equipment and the amount of training required to use that equipment to the required skill level

• What happens if you expand the volume of air into an object? Like say you create a small 1mm cube, then you expand it length wise into a wall. Would it go through the wall or just stop? What happens if you want to create a 1mm cube when there is only a 0.5mm cube of space left? If the air takes precedence, she has an extremely lethal weapon, otherwise your pretty useless agaisn't an army. They could just use a giant magnifying glass to try her using the visible spectrum. – Shadowzee Jul 10 '18 at 3:09
• Even as it's solid, the O2 parts still should be able to oxidize, so incendiary weapons should be able to take down 20% of this wall. If there is a way to oxidize Nitrogen (about ~78% of air) this wall would be well penetrable. – Herr Derb Jul 10 '18 at 7:55
• this question kind of reminds me of the 'Broken Sky' series which had certain characters able to control air into concussion bolts and some limited personal shielding. My question would be how fast can she expand/shrink her barriers? Unless she is able to move her barriers fast enough to cause damage I don't see her having any real offensive capabilities instead only having overwhelming defenses – BKlassen Jul 10 '18 at 17:08
• @BKlassen - She can't ram her barriers into people, they've gotta run into them. All her barriers have to occupy open air. ... And expansion / shrinking of the barriers happens at the speed of thought. – Malady Jul 10 '18 at 17:58
• This question is about capability (what can she achieve) not motivation (what will/should she do) so I think it's on topic. The question is trying to build and understand the consequences to the world of a person with this superpower - not building the character with the superpower. That is the critical difference. – Tim B Jul 11 '18 at 9:48

Put simply, this woman is effectively invincible, because of the ability to sleep with her impenetrable shield up.

With 10 cubic meters of potential volume, this woman can create an indestructible cube about 40 meters on each side (made out of one millimeter sized cubes). Given that she can effectively move this indestructible cube by growing and shrinking the leading edge, she can move wherever she wants with impunity. If she was skilled enough, she could even do that while operating a motor vehicle.

To refresh her air supply, she can create a second, smaller cube (after shrinking the first one) wait inside there and then drop the outer cube, she is then free to move somewhere with fresh air. Given that she has 64 thousand cubic meters of air (or 64 million liters) to work with, she has to do this at most once a day, but probably far less.

If it weren't for the constraints of the deathmatch, this woman would probably be better off just going about her life like nothing was different.

Given that she's set on mass murder, it's simply a question of walking towards the nearest target and suffocating them. Tanks and planes are no issue, as she is impervious to their assault, and if she sees the airplane she can just put an invisible wall in front of it. As for the tank, she can just wrap the air inlet valve in her magic shield and choke the engine out, or if she wants to kill the crew, just wrap the whole thing up tight and wait it out. If she shrinks her shield down she can catch a whole platoon of tanks or more and choke out both them and their occupants, very quickly if she makes sure the air intake for the engine can pull air from the crew.

She is effectively immune to any quantity of conventional weapons, so the answer to your question, assuming no WMDs are used, is infinity dollars.

Her only weaknesses are that she must manipulate the air about her without being able to move her invince-o-walls and the fact that visible light can pass through.

Not being able to move her walls except by growing and shrinking them, means that a determined opponent could flood the area with airborne biological or chemical weapons. In order to move she would have to bring some of those agents into her space, which would result in her death.

As a cost estimate this article suggest that is costs 30 million dollars to create a production facility, so we'll just double it and say that's enough Sarin gas to keep her surrounded in a deadly cloud long enough to suffocate. So that's 60 million dollars. We'll ignore what it will cost in human lives to determine this weakness or simply make them mad enough to try it, but that could potentially double the cost again, depending on factors.

The other option is a nuclear weapon, at point-blank range, so the visible light is strong enough to disable (or vaporize) the intended target. This article suggests that a nuclear weapon can be produced as cheaply as 350 thousand dollars (not counting overhead or delivery method, most likely), making it the affordable choice.

To ensure the weapon is maximally effective and delivering nothing but visible light, it will be helpful if we can get our super murderer to wrap it up in her invincible force field. That will trap the blast wave and other forms of radiation, bouncing them back in to produce more light in the visual spectrum. Perhaps the bomb can be placed inside a mock tank of some kind. A timer or suicide crew will be necessary to detonate the weapon at the right time, or some form of laser communicator.

All in all, this woman would make for a hell of a villain.

• use a laser, the barrier is transparent, a few flash bangs will still blind her. – Windlepon Jul 10 '18 at 7:46
• your stipulation that she must refresh her own oxygen supply does reveal a potential weakness, if you surrounded her with toxic or irradiated gases then when she drops her outer shell she will be open to these gases – BKlassen Jul 10 '18 at 16:06
• @Windlepon a weapon that can be negated by the power of sunglasses is not a weapon – SomeGuy Jul 10 '18 at 22:35
• @TimB The problem with that is that the walls are made out of air, which, if that air is full of deadly poison, means her inner space eventually gets filled with deadly poison. – SomeGuy Jul 10 '18 at 22:39
• @SomeGuy We totally have visible lasers powerful enough to kill her, we don't use them as weapons against people, because they cost way way more than bullets, but they exist, look at astronomical lasers and solid state lasers. – John Jul 12 '18 at 3:29

There are two questions, the largest army she could defeat and the smallest army that could defeat her.

The size of the army she could defeat is practically unlimited, though her powers are largely defensive, they can be used as an aggressive defence. She can't lift a vehicle, but any vehicle that tries to move can be ramped into the air and dropped or inverted.

She doesn't have a weapon but she can block barrels, suffocate individuals or otherwise immobilise any attacker all while maintaining a perfect shield.

She can fix blades of air as traps for people and vehicles. It's going to be nasty and bloody and all it takes is time. It seems she could even drop the air pressure in a region to effectively zero. All the while those fancy expensive bombs and planes and missiles are useless against her.

If they don't know what's going on, they're all going to die.

She is effectively immune to everything except light.

It's simply a matter of how the army goes about finding this out and then how they use light as a weapon against her. Lasers, mirrors, take your pick. We're not talking Archimedes and a dozen men with mirrors here, it's now about computer controlled heliostats or lasers perfectly focused on her. Not expensive in military budget terms, easy to design and build, minimal skills required to deploy once the engineers have built it, and, once deployed, largely immune to her powers if properly engineered.

If she's sealed her box against chemical and biological weapons then it's effectively a perfectly insulated space. The molecules don't move to radiate or conduct heat, there are no gaps for convection. A perfect oven.

If they know what's going on, she's going to cook in her fortress of air.

• @Gryphon, please don't americanise UK spelling. – Separatrix Jul 12 '18 at 14:53

It depends on who's ready for who. Since you specified that both sides are surprised, the super-powered woman would win.

Firstly she can surround herself with an unbreakable shield complete with a floor so she doesn't even have to touch the ground. Next, she fills the area around her with tiny 1mm dots at 20cm to 30cm apart from the ground to 2 meters high.

The whole area would be locked down and only she has the ability to move. She can now wander the battlefield dispatching everyone and everything.

To win the army would need to know what it's up against. If they deployed blinding lasers, the woman couldn't see and therefore couldn't use her powers.

Anything short of this they would lose.

• I like the grid idea. In fact if you put a grid of tiny dots (or blades) in front of any moving vehicle you can perforate both vehicle and occupants. – Tim B Jul 10 '18 at 12:22
• @TimB, yeah, I don't think I want to see what this lady could do to an aircraft. – Gryphon Jul 12 '18 at 14:44
• @Gryphon: is not that easy to estimate the aricraft position while it's flying 5km (not really) high, "pan & tilt" are easy, the distance is the issue. With 10m^3 and 1mm of minimun thickness she can create a barrier 100x100m wide, which is not that huge in the sky. Actually she can estimate the airplane dimension and split the barrier in tiny pieces, placed a fraction of the plane's wingspan far from each other. That would be the most nerdy yet efficient way to deal with planes, but with approaching infantry she needs to defend herself, and with few planes it would be hard to take them down. – theGarz Jul 13 '18 at 13:44

This woman seems anything but unstoppable.

The altered volumes have no visible changes, but only visible light can pass through.

So it's quite easy to kill or injure the woman, the most expensive part is to understand her true power and provide countermeasures but i don't think that's could be actually economically relevant for a first world militarized nation.

Soldiers are not stupid, so starting from a mile apart and knowing that there is a declared enemy some "artillery" (1 mile is not that far) shells will be exploded. If this seems to be a little overkill to terminate a single woman one mile apart lets pretend that some snipers exploded some ammo but the spotters saw something strange and they communicate that somehow she can withstand large caliber bullets. Artillery will start really quickly. Given that she is also ready to fight her best chances are to create a safe-box as big as possible, to keep the maximum available oxigen reserve and to have room to move easily.

Artillery shell happen to create a lot of dust and, since her safe-box is impenetrable, every spotter can see that there's something strange that protects the woman because dust clouds are moving as they are confined by a glass structure. Since Kinetic is not working the soldiers will fastly try something chemical, which won't also work untill she will need to "open" her safe-box. Kinetic weapons are kept firing anyhow, the soldiers don't know what they are facing so they won't for sure try to save some shots because apparently ineffective. At least as long as they fire the woman doesn't move a lot.

Now the woman is already in a bad bad spot: if she keeps the safe-box active she is safe from kinetic and gas, but she has a defined amount of time before she runs out of oxigen.

There's another issue in her safe-box: since "only visible light can pass" she's also deaf respect to the outside!

And this safe-box property should really remain true because otherwise she would have been made deaf (and at least in a confusional state) anyhow because of artillery explosion.

If you just add some regular flashbang granades she definitely won't be able to react:

• Because of dust/gas/smoke she can't actually see the enemy (which started the fight 1 mile away, but that could have moved relatively far, at a safe distance but in artillery range) and she would move in random direction and moreover the enemy could actually be in every direction.
• She can't hear anything from outside the box
• She have to maintain the box "on" and sealed because of the poisonus gas
• She will eventually run out of oxigen
• She would be constantly blinded/confused by a regular stream of flashbangs granade
• As soon as someone understand that the visibile light has full effect and the box is sealed the military would use laser to hurt the woman through the barrier: a normal eye could be permanently blinded by an hobbistic laser engraver with just one watt of optical power and that costs less than 20$, an industrialized nation could provide tons of these laser in hours. But in any case i doubt that this will be required. • It could be also possible to try to overheat the woman only by visible light radiation: light is still energy and the barrier won't dissipate any heat and therefore the internal temperature will raise. The only countermeasure for the woman is to let some air escape shrinking the safe box, and then re-seal the box and restore the volume: the gas expansion will low the temperature. The issue is that she's also letting some oxigen escape, reducing her reserve. TL;DR: keep an artillery barrage of kinetic, gas and flashbang shells, and she will eventually die. I suggest to use an AC-130 fleet to do that from the sky without risks for the soldiers. How much would it costs? Several millions of$, lets say less than 50, but this amount won't be anywhere near relevant as military expense for countries like USA, Russia, China, ecc..

See the edited part of the answer: i guess that, at least for the first battle day, the winner would be the one who shot first since she can literally obliterate everything in sight but only as long as the sight is not blocked by gas or dust.

EDIT: as a sidenote that come to my mind reading other users answers, the women's power is anything but only defensive! If you take 40x40x40m of normal air and compress it to 1x1x1mm (or less, which seems to be feasible given the women's power since there's no minimum limit) you can actually start a nuclear fusion. Therefore she could deliver this well packed energy cube anywhere within her line of sight, and then just release the energy by switching off her air control.

I'm not a nuclear engineer but the possibility to deliver thermonuclear millimetrical cubes at wish would be really devastating! 0_0 The only downside is that for a while (before the compression) she can't control other air to protec herself, but she can decide to compress little less air and keep just enough controlled air to protect herself.

• The air doesn't compress, she's just using the air molecules to define her barrier, she doesn't, and cannot, move them with her power, just makes them stop moving, if they're in her barriers. – Malady Jul 16 '18 at 13:30
• Right... The sentence "Created volumes can be instantaneously expand and shrunk, regardless of vision, in any direction she wishes" misled me. Allright, no huge explosions and neither refrigeration because of expanding gas, I'll then bet even more money on the military. – theGarz Jul 17 '18 at 7:01

So here's an option that will allow you to deal with a force of around 5000 combatants that are in the open. This idea won't work in a guerrilla combat environment, and forces larger than 5000 will struggle with the volume limits. Also, it only works if your air wrangler can maintain multiple 'volumes' at once.

Put simply, you can suffocate your enemy force.

The average human head is around 1500 cm3 in size (perhaps a little smaller) which means that if you allow for around 2000 cm3 per soldier, you can create a 'helmet' of a solid force around each of their heads. This helmet barrier seals around the neck, and because it's solid, your soldier will suffocate as they can no longer breathe the air as it's acting as a solid. Also, it will hold them exactly in place because the barriers are stable relative to the earth. Every barrier is also a glove-like fit for the head it surrounds, so it's impossible for the soldier to get out of it.

Give it 20 mins to be sure, then you release and you're done.

Ideally, your air wrangler should be up on a peak, able to look over the entire approaching army at once. Further, you don't want them in APCs or other mechanised weapon platforms like tanks because of the line of sight restriction. This solution fails quickly when dealing with an armour division, although putting an air barrier 'plug' into the barrels of all the tank guns so that the shells blow up inside them seems to be a logical solution to that as well.

Ultimately, this can be used as a very offensive weapon, but it involves the use of many small volumes in order to achieve it. Whether or not you're encasing 100 tanks in a thin shell, plugging 10k gun barrels, or suffocating 5k soldiers, you need to do it all simultaneously. That could be a lot of focus that needs to be maintained but it's doable with the rules you've set out.

How to defeat her? Well, it's the ant approach; superior numbers. If you have a force of soldiers larger than (say) 15k, you might not have enough volume capacity to (say) plug every gun barrel, and you will only be able to suffocate them in stages. A large number of tanks may not be able to shoot because of the plugged barrels, but they can still crush your single combatant by running her over (edit: This is of course assuming that the 'static' nature of the air barrier doesn't actually leave the tank immobile because the plug is stopping the entire tank from moving). Ultimately to defeat her, you have to overwhelm her capabilities and the 'cheapest' solution to do that would be a very large number of human soldiers if using conventional tactics. Even cheaper might be a small number of special forces soldiers trained in guerrilla tactics to sneak up on her if you have that option.

All up, your air wrangler is a very dangerous individual and if she attacks the weak points of soldiers and equipment and has a good vantage point, she's going to be able to outlast quite a considerable force.

Deception and Misdirection

The military show of force keeps her attention. They don't move forward to provoke her action, but spend the day noisily arriving, battalion after battalion, moving into initial positions that she can clearly see. Then noisily shifting position as the next unit arrives. It looks like they are trying to impress her with sheer numbers and kit...

...but they are not. A small group of snipers arrived before the first main body (preferably long before dawn), circle around and approach from behind. Avoiding her field of view might take them most of the day, but even "open, grassy plains" has dead space to sneak through.

A second group of snipers conceals in dead space in front of her, so if she walks forward she will enter their kill zones. They are the backup plan.

One clear shot during the afternoon. Battle over.

Force Estimate: 3 Armor battalions, 3 Mech Infantry battalions, 3 Light Infantry Battalions

Single-use Cost Estimate: About \$900 million in Tanks, \$225 million in Bradleys, \$30 million in personal kit (including personal weapons), and about \$500 million in the training and preparation (some of which takes years). Plus fuel and ammunition and other basic sustainment for the mission, plus housing, food, medical, parts and maintenance, etc.

Note that the more accurate mission cost is designed to be very low - if the mission succeeds, not a single tank will be damaged, not a soldier lost, and barely any ammunition expended. Only a hard day's worth of burned fuel.

However, this plan rejects the premise that the army doesn't know they are fighting a single super-powered person, who has the element of surprise on her side. This is how surprise works the other way.

• What if she solidified the air in their throats instead of around their heads? Could she then kill more soldiers? – Adrijaned Jul 10 '18 at 9:50
• If i were the woman and this military force was approaching i would have activate a barrier all around me because, you know, landmines, sniper, lethal gas, etc.. If i can easily wrap myself in a 100% covering shield why would i offer open spots? Achilles heel for military convenience? – theGarz Jul 12 '18 at 7:48

Siege

This woman has only defenses. Solid air of the volumes described is not much of an offensive weapon.

You can easily lay siege to her improvised defenses. You can defeat this woman with a ring of snipers or a few pieces of artillery. Roman technology will do. She must maintain her impenetrable barrier circumferentially around herself to protect from shrapnel or bullets. She can flash her barriers on and off to get fresh air but eventually she will get thirsty. The soldiers laying siege take shifts.

If the soldiers laying siege tire of this they can drop / throw incendiary bombs. Impenetrable air probably still conducts heat.

If she decides to advance until she sees an opponent or finds some water, she will encounter land mines / pitfalls.

• She could manipulate her barriers so she flies into the air, at a high enough altitude, she's effectively invisible? – Malady Jul 10 '18 at 0:41
• Can soldiers breath solid air? If they can't, then that's one heck of an offensive weapon. Also, if her air barriers are walls, then fresh air can enter from above. Your answer assumes combatants have identified this superwoman as the source of solid air. If she kept her powers concealed, she might be striking against unprepared or unaware forces and they wouldn't know how to handle it. Although landmines are a good idea. They might inadvertently dispose of her. – a4android Jul 10 '18 at 7:17
• If she was smart enough to make a floor of air to walk on even land mines wouldn't work. – Tim B Jul 10 '18 at 12:23

This question is rather odd... because as defensive as the woman is against physical attacks, her barriers are not shielding her against light. And Light - or rather EM-radiation - is what will make the military win as soon as they can field the right weapons.

Breaking the ability to fight

Deep Red

Yep, Microwaves are nothing more than light in the deep red sector as all light is basically EM Radiation and thus can interact with matter via Photoeffect. Even the visible Red Light bordering the IR is quite good at heating up matter. Microwaves, which are not too far away from red light have been tested for riot control means in the past. Give the woman a nasty sunburn with a very large spotlight till she surrenders or cook the woman within her protective shell of hardened air till she is dead. Just a couple of these Hollywood Spotlights should suffice. Win Miitary by breaking the opponent.

Laser

She needs to see, right? crack out a high powered laser, then aim for the eyes and blind her. No sight, no new barriers. Which means she either opens herself to other attacks like gas, surrenders or suffocates. Win Military by shattering the ability to fight.

But we can do better:

Supreme Excellence approach

To fight and conquer in all our battles is not supreme excellence; supreme excellence consists in breaking the enemy's resistance without fighting.

Psychowar

She can see if there is light. But light can be very disorienting: place strobelights all around and bombard her with a nonstop flashstorm until she screams in agony or suffers a stroke. Win Military by breaking the will to fight.

Denial

As long as the military can stop the woman from fleeing, she has to stay. As she stays, she has to support herself. And a military of just a couple hundred men can deny access to resources to her. Win Military by atrition.

Trickery

Or... they deliberately don't deny access at some points. Not because they are mercyful, but becuase the food is laced with plagues or drugs to take her out. Win military by surpreme excellence.

• "only VISIBLE light can pass through or affect the volumes" -> microwave and ir-lamp won't work at all, gamma ray and her mobile won't work as well for the same reason. – theGarz Jul 12 '18 at 13:49
• @theGarz Visible to whom? Animals can see different spectra and even humans can see the very close IR. – Trish Jul 12 '18 at 14:36
• Trish,without any other specification "visible spectrum" is intended as human visibile spectrum (in fact the question involves only humans, btw). Since every wavelenght carries energy is better to increase the emitting power of the visible light source rather than trying to justify something that's against the specs. Even thoug near IR could be borderline, microwaves are surely blocked. – theGarz Jul 12 '18 at 14:57
• @theGarz then please REREAD what I wrote. let me quote myself Even the visible Red Light bordering the IR is quite good at heating up matter. I used microwaves as an example why it works, but I never said "use a microwave source" but "large spotlight" – Trish Jul 12 '18 at 16:04
• If you say so... The paragraph is entitled "Deep Red", the first sentence is "Yep, Microwaves are nothing more than light in the deep red sector", but since you mentioned "Even the visible Red Light [...]" it's obvious that the idea to use microwaves as source doesn't actually come from your answer but depends only on my bad habit to correlate a title and the following paragraph. Oh, wait, i'm wrong again, you also made this specific example with M.W. (and not with I.R.): "Microwaves[...]have been tested for riot control means in the past." PS: to have a sunburn you should use UV and not IR. – theGarz Jul 13 '18 at 7:29