Archive for October, 2012

Fantasy League Round 5: Fashion Failure

2012/10/30 8 comments

Sometimes, the clothes of the characters on the silver screen are awesome.  And sometimes they’re just ridiculous.

Straight to the Heart

This is one of my pet peeves, as it seems to ignore the reason why armor was invented.

To illustrate — which of these two characters is going to have more issues with projectile weapons and pointy objects aimed at their chest?

That’s what I thought.  The reasons for this from a media point of view are rather obvious: showing off a woman’s skin apparently attracts viewers’ and players’ attention.  Nonetheless, it’s obvious why armor like that was never used back in the real world.  The reasons for its use in media are, perhaps, just as obvious. Everybody knows that all gamers are straight males, and no women ever deign to touch a keyboard </sarcasm>.

Though it’s usually the women in the minimalist armor (consider Xena, Warrior Princess, or any number of other shows), they’re hardly the only ones.  Barbarian types especially are also subject to this.  (That’s even when you exclude things like Captain Kirk strategically ripping his shirt.)

Even if that’s their non-fighting gear, wouldn’t they get cold eventually?

Some of the Wheel of Time books by Robert Jordan include some bodyguards with precisely this kind of armor to make people think they’re less skilled than they actually are.  It seems to me that you’d rather give off that aura of ineffectiveness by means other than making it easier to be injured.  At least when this shows up in the Belgariad books by David Eddings, the queen’s armor is deliberately ornamental — the better to look awesome while giving orders to the army.


Similarly, it’s best to have appropriate shoes for the task at hand.

I don’t think I’ve seen anybody in film wearing shoes this bad. On the other hand, these shoes may actually be real…

As an example, in Sky Captain and the World of Tomorrow, our intrepid reporter spends the entire movie, except for a brief stint in the mountains, wearing high heels.  This is manifestly not a good idea.  At least in that movie, they make a point of mentioning (and demonstrating) how the high heels are a bad idea.  Given the number of times the lady characters end up having trouble running, or tripping over their own three-inch-heels…

In other cases?  Many of the women in Star Trek are only ever seen wearing high heels — most egregiously in the original series and Seven of Nine in Voyager.  Then again, maybe they’re trying to make a statement.  “She’s so awesome, she can outrun and outgun you despite the high heels”.

Of course, there are also alternative uses for high heels.  In most cases, I suspect using high heels as a weapon wouldn’t work especially well — they’re not made for handling that kind of stress, and given that most of them aren’t knife-sharp, it would take quite a bit of effort to impale somebody with them.  That said, stomping on somebody’s toes with them would work pretty well.

No Capes!

This is Stratogale, briefly mentioned in The Incredibles. Moments after this image was taken, the drag from her cape caused her to be sucked into the plane’s jet engine.

Capes are also on the list of fashion no-nos.  The Incredibles has a whole sequence of unfortunate superheroes who meet their doom via cape-related issues, courtesy of Edna Mode.  The fundamental problem with capes is that they get stuck in stuff, caught in stuff, grabbed by your nemesis and used to fling you across the room, and so on.

It’s not just superheroes, either.  The sorcerer and evil overlord types also frequently sport capes or long fancy robes, which film and novel even occasionally have be a demonstrable problem.  But most of the time, they manage to get away with it somehow.  Consider all the fighting in long, flowing robes that the Jedi do in Star Wars.  Darth Vader has a cape, too.  And, when Industrial Light and Magic was animating Yoda showing his stuff in the prequel films, the animators found handling his robes tricky — making sure they looked cool and like they weren’t going to get tangled and trip him.

Edna Mode knows her fashion.

I still think a detachable cape could be handy, though, given the utility of using clothing to avoid getting caught.


To quote the first item on the Evil Overlord List:  “My Legions of Terror will have helmets with clear plexiglass visors, not face-concealing ones.”

This is commonly done to the mooks in movies and so forth for the simple reason that, when we can’t see their faces, we can’t sympathize.  These are the faceless Legions of Terror, and thus morally acceptable targets, not people with a family who’re just doing their job as a guard.  It also helps in that you don’t need as many extras to portray your legions.

In practice, this means that the guards can’t recognize each other on sight.  A common heroic tactic is to knock out or kill an unlucky guard, steal his clothes, and bluff to get into the fortress of doom.

Nazgûl. Face-concealment is perhaps less relevant, since it’s not clear they have faces. On the other hand, since they can’t really see, it’s not clear why they have the big opening for their nonexistent faces. Smelling out his quarry, perhaps.  Regardless, that comes back to bite this guy later.

The other side of the coin is that, oftentimes, the hero doesn’t wear a helmet.

Avatar (with the blue aliens) actually manages to get this somewhat right.  The humans are always wearing helmets so they can breathe — with nice clear faceplates so we can identify them.  (The Na’vi don’t bother with them, though.  Or much armor, for that matter.)

Otherwise, our heroic SWAT team member is the only one without a helmet.  Real SWAT teams?  Everybody has a helmet, armor, and all the other appropriate gear.  Detectives without helmets try to stay back and out of the way when the situation goes south.  After all, dealing with the dangerous parts is what SWAT teams are for.

On the other hand, the best example of helmet fail is Star Wars.  The Jedi?  No helmets.  (Also no armor, but it seems that armor isn’t much help against lightsabers.  Personal force fields, on the other hand, would be nice.)  Stormtrooper helmets also fail badly on this front.  They’re face-concealing and, according to one character who… borrows… a helmet, it’s actually pretty hard to see, too.

Of course, they’re not terribly effective anyway.

And if you’re confused, you need to watch Star Wars: Return of the Jedi.


SciFi Round Seven: Alpha Centauri

2012/10/25 10 comments

There’s a planet at Alpha Centauri.  And that’s just too cool not to follow up.  (For those of you who may want more technical information than the first link, the full Nature article is here… though it may take a subscription to see the whole thing.)

In honor of that discovery, let’s see how well some fictional accounts of Alpha Centauri stack up.  It’s a popular system to consider, since the stars at Alpha Centauri are the closest to Earth (other than Sol – aka “The Sun”) at a mere 4.4 light-years.  I’ll only be hitting a few examples, but oddly enough, Wikipedia has an extensive listing if you want to see them all…

Alpha Centauri Is More Than One Star

I was shocked to see this mentioned on the aforementioned Wikipedia page, but apparently some authors think that Alpha Centauri is only one star.  I have the good fortune to not have read any of these; I would have been very upset by them.

While not obvious to the naked eye (or authors from the northern hemisphere who don’t see it at all), Alpha Centauri is composed of two stars.  The larger, Alpha Centauri A, is a spectral type G2V, the same as the sun, has a slightly larger mass and slightly brighter.  Alpha Centauri B is type K2V, and is noticeably cooler and dimmer than the Sun, and has about 90% of the Sun’s mass.  The two stars are close enough in mass that the system’s center of mass is well between the two stars, not near the center of one or the other.  Their orbit is eccentric, with the distance between the two stars varying between roughly 10 and 50 AU.  For scale, that closest pass is about the distance between the Sun and Saturn.  There’s a nice animation of this, along with other information, which also shows an estimate for where the habitable zones of the stars may lie.

On top of the bright binary, there’s a third, even dimmer star called Proxima Centauri (or sometimes Alpha Centauri C).  It orbits around Alpha Centauri at a distance of about 15,000 AU.  Its spectral type is M5.5Ve — at a bit over a tenth of the Sun’s mass, it’s much dimmer, cooler, and redder than the Sun or Alpha Centauri AB.  The “e” means it’s an actively flaring star.  More on that later.

Moving In

Sometimes it’s only mentioned in passing, but fictionally speaking, Alpha Cen is a common waypoint or colonization target.  It gets mentioned as such, and occasionally featured, in such things as Star Trek, Lost in Space, Buck Rogers, Doctor Who… the list goes on.  A couple of books that mention or feature Alpha Centauri are The Songs of Distant Earth by Arthur C. Clark and Foundation and Earth by Isaac Asimov.  In the movie Avatar, the moon Pandora orbits a gas giant which in turn orbits Alpha Cen A.  Sending a colony ship there is a method of winning the game in Civilization, and it’s the name of the game Alpha Centauri.  Typically, these works imply or require the presence of at least one habitable planet orbiting either A or B.

The recently discovered planet is Alpha Centauri Bb.  It has a mass somewhat greater than Earth’s, and orbits Bb at a radius of 0.04 AU.  Despite the fact that B is dimmer than the Sun, that means this little planet is baked to a surface temperature of at least 1500 K (depending on its albedo and atmosphere).  That’s hot enough to melt silicate rocks, and is at least twice as hot as Venus (which averages 735 K).  Odds of anything living there are pretty slim.

Artist’s conception of Alpha Cen Bb, which really needs a better name, in orbit around Alpha Cen B. The color scale is logarithmic, with brightness ranging over a factor of many trillions. Alpha Cen B is ~100,000 times brighter than Alpha Cen A as seen from Bb, the Sun is not quite a billion times fainter than Alpha Cen A, and the galactic plane is fainter still.

Because Alpha Centauri is so close, there’s enough data to give good limits on what other planets could be in the system.  Anything habitable must be orbiting either A or B relatively closely in order to be warm enough and to avoid having its orbit perturbed too much by the other star — but not too closely.  The combination of these two requirements makes it difficult for a planet to stay in Alpha Cen A’s habitable zone — it’s likely to get scattered out by B.  This may be a problem for works that put the habitable planet around A, such as Foundation and Earth.  B, on the other hand, may have less trouble with this, since its habitable zone is closer in.

Planets far enough out to orbit outside the AB pair would be too cold.  C is an unlikely candidate — it’s so small that any planet close enough to be warm enough for life would be close enough to be seriously zapped by radiation from the flares, which would (probably) erode its atmosphere.

Back to Avatar.  The moon Pandora orbits a gas giant, which orbits A.  Even assuming it gets away with orbiting A, there’s another problem.  Despite some false alarms, current limits indicate that there are no gas giants or brown dwarfs anywhere close to A, B or C.  Pandora doesn’t exist.  (And who names their moon Pandora, anyway?  But we’ll cover Avatar another day.)

On the other hand, that leaves plenty of room for speculation — smaller, rocky, habitable planets are possible, and more plausible around B.  The stars in the system are also older than the Sun, which means there’s been plenty of time for life to develop…


If the aliens are the technologically primitive (no radio) Na’vi, it’s pretty obvious why we haven’t heard from them yet.  Or they could all be a hundred years dead.   On the other hand, if we’re talking about aliens like the fithp in Footfall (by Larry Niven and Jerry Pournelle), then we’ve got a problem.

Contact with aliens from Alpha Cen is another common theme, with technologically advanced aliens an option.  In Footfall, they’re in the form of an unusually plausible group of alien invaders.

There’s just one problem.  We’ve been putting out radio signals for over a century, and relatively strong ones for television broadcasts for over seventy years now.  Those signals, while usually not decipherable, are still detectable and clearly artificial for a sphere sixty or seventy light-years in radius and expanding.  If we ourselves were sitting at Alpha Centuari, with our current technology, we could unambiguously detect those radio signals and notice both Earth and the fact that it’s inhabited.

By the same token, if Earth with all its radio chatter were orbiting Alpha Cen B in the habitable zone… we’d have heard them by now.  At least one of the books listed in Wikipedia (Factory Humanity) seems to get this right — contact with aliens at Alpha Cen is established first via radio.  Why we didn’t hear the fithp before they decided to take a detour through our solar system isn’t clearly explained.  Maybe they’ve replaced all their radio tech with subspace transponders.

Either that, or they’ve seen us, and are deliberately hiding.  Just like the Martians.  Insert your conspiracy theory here.

Fantasy League Round 4: Economics and Fantasy Role-Playing Games

I keep talking about the importance of considering what technologies (in the broadest sense of the word ‘technique’) can do to a society when writing a story.  In many stories, the technology itself isn’t the purpose of the story that was being written.  Inception is a heist film – in some sense, the dreaming technology is less relevant than the interactions between Cobb and his memories of his wife, and his quest to return to his children and home even if that means assaulting Fischer.  This is the second of Asimov’s three kinds of science fiction: the technology is incidental to the adventure.
But what about role-playing and strategy games, where the techniques concerned are the main way that the players’ characters interact with the game world?  Here it is essential to consider how the technologies interact with one another, in the form of possible combinations of the rules.  Otherwise the game may end up essentially unplayable.  Most good games don’t have that severe of a problem, but considering all of the possible combinations of rules becomes very difficult for complicated games where the full description of the rules may be hundreds of pages long.  In particular, economics is very hard to do right.

Game Breaking

If the game developers and beta testers haven’t found and fixed all possible problematic combinations of rules, there will be exploits to take advantage of.  And given a large enough base of players, they will be found.  There are very long lists of such game-breaking techniques, but here I’ll focus on economic ones.

The economics of Dungeons and Dragons 3.5. Notice that a 10-foot ladder costs 5 copper pieces and a 10-foot pole costs 2 silver pieces = 20 copper pieces. So, buy ladders, take them apart, and quadruple your money. That works until the demand for ladders and poles changes and the prices adjust; but price elasticity isn’t included in the rules for the game.

In all of the versions of Dungeons and Dragons, there are exploits that allow relatively low-level characters to defeat any opponent.  The most notorious example is Pun-Pun, a level-1 starting character in DnD 3.5 that has arbitrarily high power.  But the exploits in DnD are easier than that.  The purchase price of a ten-foot ladder is less than the sale price of the two ten-foot poles and shorter rungs that it is made of.  A player can in theory drain all of the cash out of the local economy.

In the Dresden Files RPG, there is another simple exploit.  A lot of the competitive balancing in the game relies on high-powered magical characters being unable to use complicated technology, particularly computers and other electronics.  This is justified by the characters ‘magical energy’ damaging the electronics.  They are walking techbane.  But moving water is also established to block magical energy.  You can still use a cell phone, a GPS, a computer terminal, and all of the fancy gadgets in a modern hospital as long as either they or you are encased in a thin layer of circulating water.  Time to go shopping at a fire-fighter uniform supplier.

In Mage: The Ascension, some characters can magic the laws of probability and win the lottery.  That may get a certain amount of unwanted attention, but you only need to do it once.  To deal with this sort of thing, all of these games have one basic rule: the moderator is always right.

Competitive Balance

Things get a bit more problematic in games without a moderator constantly adjusting the rules to avoid or limit game-breaking.  It doesn’t even have to require a large player base – AI programs can do the same thing.  In 1981 and 1982, a challenge using the rules from the sci-fi RPG Traveller was twice won by an early learning program.  It found that thousands of kamikaze ships would defeat any other solution.
A more recent example:  Starcraft is very close to competitive balance, but in scenarios with nearly-infinite resources and equally-skilled players, the Protoss game race has a slight advantage over the others.  They can assimilate enemy units and potentially have three times the army of anyone else (if the game lasts that long).

Game software can be updated.  This is easier for online games.  In World of Warcraft, there have been both positive and negative game-breaks.  On the positive side, there was a bug that could be exploited to allow a single paladin character to do death by a thousand cuts to the hardest-to-defeat enemies in the game in one move (as opposed to the usual method of two dozen characters taking several minutes to bring it down).  On the negative side, a programming bug caused the Corrupted Blood debuff to turn into a pandemic inside the game, killing off or wounding almost all characters.  Those were all fixed by obvious rule patches in short order.

The Limits of Rule Patching

But rule patching can only go so far.  The most complicated game breaks arise from interactions between many player characters, in effect a large synthetic economy.  The World Of Warcraft internal auction markets are nowhere close to equilibrium, and arbitrageurs can make lots of in-game money.  In some cases, trading bot programs have accumulated up to several times the total amount of money in circulation on any one game server.  Blizzard deals with that by shutting down bot accounts whenever they are detected.  But  Matt Fisher at Stanford tells me that bot programs can be programmed to appear almost identical to a human player who obsessively trades on the market, so there is no way to fix that.

Perhaps the limits of rule patching can be excused.  When game systems are so complicated that no-one can predict their outcomes, and when they involve the interactions of thousands of separate agents, fixing problems with them is as hard as fixing problems with the real-life economy.  Doing significantly better than random chance would be impressive.

SciFi Round Six: Sky Captain and the World of Yesteryear

2012/10/13 2 comments

It’s nostalgia time.  Set and styled to match 1939, “Sky Captain and the World of Tomorrow” was made in 2004 and deliberated hearkened back to the old sci-fi adventure films of that era.

Which is to say, there might be some issues here, in between the cool cinematography, ray guns, and the robots that remind me of Gort.

Alas, that book covers are never as accurate as movie covers. Though, Franky (with the eyepatch) didn’t seem that major a character to me…

Since there’s just… so much gone awry in this kind of film, I’ll stick to the highlights.

I can haz generator?

This is one of the things that always gets me about Superman films.  Much as I like Superman, it’s kind of weird when he picks up a building, or some other huge object… like an island… and it doesn’t collapse around the point where he’s holding it.  Seriously, folks, big structures hold up a lot of weight, but only because it’s distributed around the base of the building.

The giant robots fly or stride into New York City, break a bunch of stuff, and then proceed to steal a bunch of generators.  And then hauling them off.  That kind of thing is not made to withstand the strain of being picked up and flown about by mecha.  I’d hate to be the guy trying to fix those when they got back to the base.

It’s also odd that it’s somehow easier to steal a bunch of generators, rather than the material for constructing them… if you did that, you could get your doomsday-powering devices to your own specifications, and, as a plus, when they’re finished, they’re not also damaged from having been stolen from New York under the watchful gaze of…

Ace Pilot Sky Captain of Awesome

Captain Sullivan is apparently the only guy to call when robots threaten New York.  In fact, he is the only guy they call — not the airforce (the army air corp then), or the rest of the army or the navy.  And when Sullivan goes to take the numerous robotic invaders down, he doesn’t even bother calling in the fleet of other pilots who are under his command.  Which, while dumb in the real world, apparently works because of conservation of ninjutsu.  Or because the sky captain is just that awesome.  Or something.

Where’s Jenning’s Guards?

Walter Jennings is the last of a group of seven scientists who worked together in WWI to have not mysteriously vanished.  He fears for his life, and apparently knows he’s going to be next.  Polly Perkins also knows this.  Why is Jennings not under police protection or surrounded by private bodyguards, to prevent him from being captured or killed?

Amphibious Flying Machines

Actual amphibious airplanes exist.  They take off and land on water.  These planes?  Are like the flying sub from Voyage to the Bottom of the Sea (a similarly entertaining show and just about as realistic).

But, to point out a single problem with these:  If you want a sub, you need to have ballast.  That is, enough weight to hold you down at a given depth despite the fact that a large fraction of your ship’s volume is going to be filled with air, and to adjust your weight to adjust your depth.  This is typically done with ballast tanks, which have air and water pumped into them, varying the weight of the sub.

This is not something you typically have in an airplane, which is not built to sink or to withstand the pressure of being under water and runs on jet fuel with 70%-80% the density of water.  And then, there’s also the problem that your propellers, rudders, and so forth, are all designed to move air, not water.  It gets worse from there.  Where’s the oxygen to burn with the jet fuel coming from?

Since I talked about the SHEILD helicarrier in a previous post, I won’t go over in detail the issues with Franky’s helicarrier… er, I mean “mobile airstrip.”  (And yes, she’s the one with the eyepatch.)

Noah’s Rocket Ship

The bad guy, Totenkopf, thinks the world is doomed, and all the bad stuff he does is towards building a modern ark and launching it into space with animals, two by two, to preserve and repopulate the world later.

This is not going to work.  Two animals, for a lot of species, is just not going to be enough to restore the population.  And even if it that first pair is remarkably fertile, later generations are going to be very incestuous and inbred.

There was also no mention of plants.  Presumably, the animals have to eat something.  It’s also not clear how he was planning on propagating the human race from a couple of mystery vials of the best essence of mankind, distilled into a new Adam and Eve.  Maybe he had some kind of incubator which will grow a person or animal starting from an embryonic stage, which might also mitigate the animal propagation bottleneck … somewhat.

This is all worsened by the fact that the giant rocket also has a humongous empty space running through its center.  Contrary to the obvious, space is at a premium in space.  At least, pressurized space.  Think of all the plants, extra animals, and other supplies you could store in there!

But, probably the worst problem in the whole film has to be…

Setting the Sky on Fire

It’s stated that when the ark-rocket gets high enough up, it will fire its boosters, which will ignite the atmosphere and kill everything on Earth.  (It shows up in Voyage to the Bottom of the Sea, too, though in a different form.)

The idea may originate from a theory associated with the Trinity test, where some scientists feared that they might ignite the atmosphere when they set off the bomb.  This was considered to be a rather low-probability outcome, obviously.  (The link is a paper discussing how this is not going to happen.)  The idea was that, if the bomb was big and hot enough, it might be enough to start a fusion chain reaction in the air.  But, between the temperature and density of the atmosphere, the amount of energy released from, say, the fusion of nitrogen nuclei, and how quickly the particles from that fusion disperse… even if some nitrogen were to fuse, it’s not enough to sustain a chain reaction.  Nitrogen can be fused in stars more massive than the sun, but the conditions on Earth are such that it’d take something way, way, way more serious than even Project Orion (a proposed nuclear-bomb-propelled rocket) to make the atmosphere burn.

And then, of course, there’s the irony that by assuming the world is doomed, Totenkopf attempts to preserve whatever he thinks in the  world is worthwhile, and send it off in a rocketship whose boosters will doom the world.  What.

Superheroes Round 1: The Avengers

2012/10/10 5 comments

Superheroes… the modern myth.  It’s not fantasy — there’s generally a dearth of wizards.  And, well, while I’d count it as science fiction, it’s so squishy in terms of the “science” part… and there’s so much superhero stuff, it deserves its own category.

So, let’s start with one of the big, recent ones.

These are they Avengers. Unlike book covers, the characters actually look like this.


Since this is a let’s-get-together superhero film, I won’t be worrying about the issues with the individual superhero’s powers so much here, and (mostly) taking those as a given.  That said…

The Joint Dark Energy Mission

That cool facility at the beginning that was doing the cool research?  They stole a real acronym.  The real thing was a planned telescope for looking for the cosmological kind of dark energy — whatever it is that’s making the expansion of the universe accelerate.  It’s since been blended with another project, and the current planned mission is called the Wide Field Infrared Survey Telescope.  If you really want to know more, check out “dark energy” or “physical cosmology” on Wikipedia.  You will notice a distinct lack of tesseracts.

Dude, It’s Loki

You’ve got Loki.  And you know he’s planning things.  Even while he’s all-too-happily in captivity…

… why are you just sitting there with Loki in your hold?  Why not Just Shoot Him?  Or, if that’s too evil, why not send him back to Asgard with Thor?  Or at least, seriously, take him somewhere other than the base right next to all your nice toys, where he can sneakily sabotage things and try to distract you from his real plan.  Then all you have to do is head off with the tesseract, and you’re good.

Dude, You’re Loki

Um, if you’re planning some vengeance and conquest… why start the gloating before you’re done?  That distraction while you were detained was not so helpful.

And Fury?  You had him down for the count at the beginning.  Why don’t you Just Shoot Him when you have the chance?  Or even better — mind control him!  He’s be a useful tool, if he could wear shades to hide the glowing eye of mind control… or maybe just one contact.

And really.  Keep a closer eye on your tools, and don’t let your mind-controlled scientist build an off switch to your gate of doom.  And when you can’t mind-control Iron Man, why don’t you Just Sh– oh, I said that already.  And for pete’s sake, don’t start lecturing the Hulk while he’s close enough to beat you up.

The mind control is great, by the way, but if a concussion is all it takes to break it… that’s pretty wimpy mind control.  You have to keep an eye on your minions.  Why are you even bothering with the distraction on the helicarrier?  Why not, say, plant a decoy source of gamma radiation in Australia?  You’ve got all that Asgardian know-how.  Use it.

Seriously, man, it’s like you haven’t even read the Evil Overlord List.

The Helicarrier

Let’s do a little math.  The helicarrier looks a little like a Nimitz-class carrier.  So, let’s say it has about the same mass — roughly 100,000 tons.  Assuming it doesn’t have a magical arc reactor (since it’s unlikely Tony Stark would sell them one), let’s assume it has the same kind of power generation as the aircarrier.  That’s two nuclear reactors, that give 104 MW each.

Now, let’s assume we can scale up a typical helicopter.  It won’t scale perfectly — it should be harder to lift the helicarrier than the same mass of helicopter — but it’s a place to start.  A Black Hawk helicopter has a power-to-weight ratio of 158 W/kg.  (In other words, it takes 158 W per kg of weight in the chopper to keep it up.)

Assume the helicarrier is equally efficient, that means it takes about 10^8 W, or about 10 GW… which is more than any stationary nuclear power plant on the ground produces.  And about fifty times what an aircarrier can produce.  This thing can’t hold itself up.

If you do a similar calculation for the air pressure difference you’d need to keep it up, you’d find that even sheer vacuum above the deck wouldn’t be enough when they’re flying at altitude.  Or you could calculate that the blades would have to force air downward at several times the speed of sound…

And let’s not even get into the cloak.  Even it if worked, you’d still hear it coming.  And then there’s all that waste heat…

Power The World

And then, the exploit: we could have powered the world with the tesseract, but it’s too dangerous.  Fine.  Instead, let’s build lots of those arc reactors, like the one Tony’s using to power his office.  That’ll work great, right?  Loads of long-lasting clean energy?  Why are we not doing this already?

And if you want to have a look at someone else’s take on The Avengers… look here.