The Physics Of Dragonflight

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The Physics Of Dragonflight

Post by Corva »

Or, Charcoal powered Dragons.

https://sites.google.com/site/anthonysg ... on-physics

Very... Tolkienesque, to be honest. Morgoth's creations were described in such biomechanical cyborg terms.
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Re: The Physics Of Dragonflight

Post by Tempest »

An interesting read, it has a cybernetic approach, which give some hints about the author's field of study... aeronautics perhaps. But the main problem would be with heat generation and how to cold down such a creature and prevent it from cooking itself from the inside. Combustion engines are also difficult to use in a biological organism since you need to efficiently transfer the mechanical energy created into useful movements; be it by using a crankshaft, a system of gears and/or pistons. The person give some explanations about how this would work, but it's more suitable for a half-machine half-living creature than a purely biological one. Moreover, the inherent inefficiency in the transfer of energy would make the creature explodes (due to heat making the water boil inside them), leaving hot bloody pieces of internal organs everywhere.

It's one of the reason why elephants have a very low metabolism and a mouse a very active one (hummingbird being an even more extreme example), or that horse can suffer from hyperthermia much more easily than a human does (in ancient time, a hunter would kill far larger prey by tracking it to the point of exhaustion or more specifically to the point of inducing a heat stroke). This is a consequence of the Square Cube Law where the volume increase much faster than the surface of the creature as it gets bigger. Moreover, bones strength (and structures in general) are surface dependent so again, it's the reason as why you can step on a hot wheels car without damaging it while something the size of Godzilla would turn the real version of that car into a pancake. So the bigger the creature, the (proportionally) weaker it get structurally without relying on some exotic material.

I think one point also need to be corrected is that heat makes metabolic reaction faster. Well, yes and no. Yes, if we look purely at the chemical reaction itself, but living creatures don't have uncatalyzed metabolic pathways, since it would take forever to metabolize anything. As such, each reaction has a optimum peak temperature before the reaction and enzymatic activity abruptly fall. In general, that temperature is often around or a few degree more than the creature's typical body temperature. But it's a tricky balance; a greater temperature can speed up some reactions (ex: fever), but if you get past a certain temperature (~43ºC), you die as proteins inside your body began to break apart.

So yes, you can find energy-rich substances such a coal and oil to meet the energy requirements and allow a large creature to fly but having an energy source and being able to properly use it is a whole new ball game. Even if the dragon has some sort of internal engine, it would still need to efficiently transfer this energy to power hundred of different muscles in its body (well, at least a few dozen that are relevant to the problem at hand here). And motors are usually best at powering a very limited number of actuators, for example, a robotic arm would have several different motors to move itself into different directions.

But for a bio-mechanical dragon, then that certainly is a good explanation.
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