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I need a scientific reason why dragons might be able to fly, given their unsatisfactory mass-to-wingspan ratio.
June 14, 2012 6:51 AM   Subscribe

In the context of this fictional world, magic exists, but it abides by very strict scientific laws, similar to Equivalent Exchange. I need some rational-sounding explanation for why a dragon might be able to fly.

Some caveats:
1) Dragons are intelligent creatures with magical abilities.
2) Magic primarily affects energy rather than matter (I know technically it's the same thing, but I refer primarily to exciting/calming molecules rather than rearranging them).
3) Although if a molecule is excited enough, it can be altered directly through ionization.
posted by wolfdreams01 to Grab Bag (30 answers total) 4 users marked this as a favorite
Is there some kind of magical mechanism by which a link can be established between two things that are not close together? Because your dragons might each be tied to a volcano, and the energy they use to fly (and breathe fire) is directly transferred out of that volcano.
posted by Tomorrowful at 6:56 AM on June 14, 2012

Why can't the wings be large enough to generate more lift than gravity's pull?
posted by michaelh at 6:57 AM on June 14, 2012

How large / massive are the dragons? Why does magic have to enter into it?

If they are, say, reasonably within the outer limits of large birds, and have wings, then they fly the same way birds do.

You can even scale them larger if you want, although of course at some point you run into the square-cube problem (their bones have to be heavy in order to support all that flesh, which adds weight, and the amount of food / energy that they need to consume just to stay alive, let alone perform energy-depleting tasks such as make fire or fly, goes way way up.
posted by gauche at 6:58 AM on June 14, 2012

Oh, missed the title. Have them excite the air above them, decreasing its density, so they benefit from air pressure below them.
posted by michaelh at 6:59 AM on June 14, 2012 [3 favorites]

Massive, magically heated hot air sacs which draw from ambient heat and sunlight. You might have to modify some descriptions to accept the reality of drifting Hindendragons but I can't imagine what story wouldn't be improved by giant lizard blimps
posted by theodolite at 7:02 AM on June 14, 2012 [10 favorites]

What if they create, as a byproduct of their metabolism (which itself might be magical), some sort of naptha or other flammable phlegm-like product, and they use the heat from burning that product to create updrafts which they catch in their wings (kind of the opposite of what michaelh is saying, on preview).

You could also contemplate having the majority of their body by area be wing rather than torso, (think very small mouse with large-ish bat-wings).

Combine these ideas and maybe your dragons fly not like birds but kind of more like a cross between a hot-air balloon and a sailboat.
posted by gauche at 7:03 AM on June 14, 2012

Magnets! Have the dragons have metal scales that repulse iron in the planet core.
posted by These Premises Are Alarmed at 7:03 AM on June 14, 2012 [2 favorites]

The Flight of Dragons by Peter Dickinson and Wayne Anderson (not the kid's paperback, this is a longer pseudo-scientific book along the same line as that Gnomes book everyone seems to have) goes into extensive detail on how dragons could have existed. Mainly involves them using hydrogen to become living zepplin-type animals. This also explains the fire.

The book also includes a nice analogy of the square-cube problem with bricks and dinner plate wings to show why you can't just keep increasing the wingsize, like michaelh suggests - the weight of the wings has to be added to the lift required, and you can never get ahead.

Also see previously, previously
posted by Wretch729 at 7:05 AM on June 14, 2012

Their dorsal scales can be solar collectors while the ventral scales can be heat energy emitters. The dragons' bodies store solar energy and, when they need to fly, they release it to generate lift. The dragons can have some sort of magic artifact that makes this process super-efficient (i.e. generating more output energy than input) so that it actually works.

They can also have evolved senses to detect wind current the way that dogs can detect faint odors and platypi can detect electromagnetic field. That way they can make sure they're always flying in optimal conditions.
posted by griphus at 7:12 AM on June 14, 2012 [1 favorite]

Turn dragons into some sort of giant biological jet engine? Inhale air, excite air with magic, mix with intestinal gases, expell from behind in jet of flame. I mean, sure, they're propelled by burning farts, but I dare you to make a joke about that to their face.
posted by EndsOfInvention at 7:27 AM on June 14, 2012 [3 favorites]

if a molecule is excited enough, it can be altered directly through ionization.

Ok, so if you don't want hydrogen gasbags (a great interpretation of dragons, btw---efficiency goes up with size, so fire-breathing sky whales are a real possibility), let's consider flight by ion thruster. The dragon flies by generating a hot plasma electrically and ejecting it opposite the way it wants to go---an electric rocket engine.

Ion thrusters can't work in the real world in atmosphere because the thrust returns for electric power generation/density are so low. For a magical dragon with massive power reserves (this is the magic bit), this might not be a problem though. Do you want your dragons to drip blue and violet fire when they fly? Standing behind one during takeoff would be like putting a hand into a plasma cutter. These dragons would be amazingly dangerous.

If they can generate plasma, dragon fire wouldn't be some smoky red smudge either, but rather more like a welding torch. In most "medieval" settings nothing would be hotter than dragon "fire".
posted by bonehead at 7:31 AM on June 14, 2012 [5 favorites]

It was always thought that bumblebees shouldn't be able to fly, for this vary reason. And yet...
posted by Citrus at 7:37 AM on June 14, 2012

If magic is primarily a Force that works on energy, perhaps think of it along the lines of:

W = Fd.

W(ork) is kinda equivalent to Energy
F(orce) in this context may be gravity
d(istance or time)

So, in the case of dragons flying you might rejigger it to work/look like:

M(agic) = g(ravity)d
the purpose of magic would be (essentially) levitation

The amount of magic used is equal to overcoming the force of gravity * how far the distance traveled is/will be or simply how long gravity is to be modulated.

The only thing missing is whatever the propulsive force will be. In Guards Guards Terry Pratchett had a small dragon flying about by,er, rocket force/flames shooting out it's backside. Much more sedate of course would be wings tailored for strictly horizontal propulsion rather than lift.
posted by edgeways at 7:47 AM on June 14, 2012

Would it work for their bones to be made out of something light but very strong? Or perhaps hollow, and filled with a lighter-than-air gas that is jetted and ignited for fire-breath, etc?

This could have interesting offshoots: the need for a dragon to choose between loiter time aloft and fire-breathing, the possibility that hollow dragon bones could be sought after as gun or cannon barrels, etc.

Although I think I like Griphus' idea better.
posted by snuffleupagus at 7:56 AM on June 14, 2012

(Upon reflection, this just tries to make the dragon-blimp less blimp-like. But maybe using a composite-like or hollow skeleton could help lend plausibility to the other ideas.)
posted by snuffleupagus at 7:58 AM on June 14, 2012

Magic that draws air under the wings so the wings are beating on really dense air. Like a big magic Bussard ramjet.
posted by whuppy at 8:08 AM on June 14, 2012

Similar to what whuppy suggested, if they can alter the density of air above and below the wing, they should be able to generate more lift. This is an equivalent exchange and changing pressure is related to changing temperature ("exciting/calming molecules").
posted by demiurge at 8:35 AM on June 14, 2012

even in a world where magic is understood to be something that follows strict rules, surely there could be room for something magical and poorly understood. Hell, make them Wingless dragons that can fly and defy all the rules of magic.

(every time Hermione says something like, "Harry, that's impossible!" in the Potter books it drives me nuts. Like, come on, you didn't even know magic existed a few years ago...maybe there is more to heaven and earth and wand lore than you can comprehend.)
posted by th3ph17 at 8:40 AM on June 14, 2012 [1 favorite]

Magic that draws air under the wings so the wings are beating on really dense air.

airflow. Dragon wings would do static lifting and steering duty, rather than flapping. Dragons thus don't need huge muscles to fly.
posted by bonehead at 8:41 AM on June 14, 2012

Due to gravity their exhaled breath falls below them, but forward motion ensures it is drawn under them as they fly. A by product of the system that generates fire breath also strongly ionizes air as they inhale it. The dragon's lungs act as a centrifuge, pulling the protons down, and electrons up. There the electrons are absorbed in the blood, to replenish ones lost in the dragon's metabolism, which result in an overall positive charge. The protons in their lungs get exhaled, fall below them, and the two positive charges repel each other.

The system is greatly aided by the angle of attack of the wings, and the wing's ability to cultivate a massive bubble of their positively charged breath underneath the dragon, always moving backward and pushing them forward.

Not all that different from a research project I'm working on...
posted by jwells at 8:44 AM on June 14, 2012

Some sort of dense ramjet?
posted by MangyCarface at 9:18 AM on June 14, 2012

Oh! Hollow bones could mean that the wings have open space at the front (like a bunch of forward-facing pipes.) Put small, individual ramjets in this wing structure, have the dragon nosedive to kick it into gear and there you go.

I guess that would imply that the dragon secretes some sort of natural bio-fuel, though.
posted by griphus at 9:23 AM on June 14, 2012

There really isn't any way around it: you need magical anti-gravity.

Here's your double-talk: The reason it's hard to lift things is because the potential energy of the object rises as it does. This new magical power changes that. It reduces the amount of potential energy that an object acquires when it rises. That makes it easier to lift, so (for instance) a dragon needs smaller wings in order to fly.
posted by Chocolate Pickle at 9:46 AM on June 14, 2012

Why not give them the ability to accelerate time within the confines of their own body?

Just enough to make air say half as viscous as water from their accelerated point of view, so that they would fly like penguins or manta rays do, and you could retain the conventional visual image of dragons because the ridiculously small wings would actually be functional. Maybe also make it so that heat is reflected at the time-change boundary so they don't heat everything else as they pass-- except that they would get rid of metabolic heat through their breath, which would give you the fire breathing. Their tremendous appetite would be a side effect of the speeding up of time, and their ability to live to a great age would be an evolved adaptation to keep them from aging to senescence in normal time because of so much accelerated time.
posted by jamjam at 10:06 AM on June 14, 2012 [4 favorites]

More on the lighter than air idea, how about they're exceptionally light (magically of course) and taking in a huge breath they separate out heavier gases, breathe those out, and become less dense than air. To land they expel the lighter gases, (or ignite them). They also need to collect heavy things in their lairs (metals and gems) to gulp up while on the ground to give themselves mass and keep from being blown away by wind.
posted by monkeymadness at 10:39 AM on June 14, 2012

Wow, there's a lot more creativity in the responses than I expected. I should probably clarify a little: this is a cyberpunk setting and the main antagonist is the dragon CEO of a technology company. He had a wing (and a forearm) burned away a long time ago and had to replace it with a prothesis that functions like a VTOL wing with multiple fan ducts. However, the loss permanently embittered him because he will never fly as naturally or feel as comfortable in the air as he used to.

While I really like the ion jet idea, I'm not sure it fits in with what I'm trying to accomplish (which is totally not your fault: I should have been more specific in the first place) because it seems like it wouldn't really hinder flying efficiency much to have an artificial prosthesis. Is there any way I can modify that idea somewhat to make it more accomodating to my theme?
posted by wolfdreams01 at 10:50 AM on June 14, 2012

I've really enjoyed this discussion, but my actual advice is to not overthink it. Your first paragraph describes the situation perfectly.
posted by whuppy at 11:04 AM on June 14, 2012

Planes fly, despite their mass. Dragons have the ability to boost their already high metabolism on a short-term basis, like thrusters, to allow them to become, essentially, rocket-propelled for launch and thrust. Their lizard-y skin over light bone frames allows them to act as highly maneuverable gliders, catching updrafts, and gliding long distances, then diving for prey and using their metabolic thrusters to regain altitude.
posted by theora55 at 11:14 AM on June 14, 2012

A potential why a prosthesis would not work as well as the biological: traditionally, iron/steel has a negating effect on magic. Make some component of the prosthesis not replicable in any other metal but iron-based metal (for gobblitygook reason) and you have magic bio/prosthetic conflict galore.
posted by edgeways at 12:54 PM on June 14, 2012 [3 favorites]

it seems like it wouldn't really hinder flying efficiency much to have an artificial prosthesis.

This is pretty much what I'd go with. Dragons and whatnot exist in magical stories because magic allows us to fudge the numbers when writing fiction. There is no scientifically sound way that a huge quadruped could actually fly the way dragons are depicted. So you don't need to break your back trying to think of a reasonable way he could be flying - there isn't one. There's only good enough.

Think about Star Trek: How can they travel faster than light? Dilithium crystals. What are dilithium crystals? It's not important and it's never really explained. This is a perfect example of good enough. Writing fantasy or sci-fi (or writing it well, at least) isn't really about figuring out the D&D rules of your world and then implementing them - it's about sleight of hand. It's about constructing a situation in such a way that the reader believes you did actually implement the aforementioned rules.

Sooner or later, a work of fantasy or sci-fi is going to ask the audience to swallow something completely preposterous, and if it's done right, they will never know it happened. Think about Jurassic Park (the movie, not the book - I've never read the book so can't really say): I was watching a special on the movie and one of the writers pointed out something I hadn't noticed. They couldn't figure out a way that the scientists would have been able to go from having dinosaur DNA sequenced to having dinosaurs and dinosaur eggs, so they just...skipped that part entirely. I'd wager that most people never noticed that.

So. How do your dragons fly? Not important. They fly. It's established from the beginning that dragons fly, and no one ever questions it, and there's never an "As you know, Bob" speech.

And then: Flying, no matter who's doing it, is about more than just pointing your wings in the right direction. It's easy to think of it that way because there are creatures designed to do it incredibly well. It's second nature. But like walking or riding a bike, we never think much about how very many different parts of our body and mind are working together to keep it going. And you can walk with a prosthetic leg...but what about dancing?

Your character has a prosthetic wing which, like a prosthetic leg, broadly performs the basic functions of what it's replacing. Artificial limbs throw off the kinesthetic sense. He can flap it just fine and angle it for gliding, but flight is about more than flapping or gliding. It might work as a wing but it won't provide the same sensory feedback he'd get with a real wing. He won't be able to feel air or thermal currents with it; he might lack fine control.

Think about riding a bike down a steep hill and then trying to turn a corner while retaining as much speed as you can. Broadly it seems easy, but think about everything that works to make it happen. Think about the fine control you need to gauge your momentum and brake just enough to make the corner without flying off. Specific tilt. Things like that.

Or watch video of birds of prey swooping in for the kill. There are a whole lot of things at work. Wing position - even feather position. It's all very precise.

In short, he can still fly, but he can't maneuver nearly as well as he did before, and it makes him feel like, well, a cripple. All of this can be condensed down to a sentence or two of exposition.
posted by FAMOUS MONSTER at 11:10 AM on July 27, 2012

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