The next essay is reprinted with permission from 
The Dialog, a web-based publication masking the newest analysis.
Like many individuals, I’ve lately turn out to be fascinated the lives and loves of the ruling lessons of the individuals of Westeros, the place the sometimes charming inhabitants spend plenty of time bickering about who’s in cost. Sport of Thrones could be very entertaining – however don’t get connected to any of the characters, because the lifespan of their world does appear fairly variable.
One of many many aspiring rulers – Daenerys Targaryen – spends a good bit of her time round and sometimes driving dragons. My background as an aeronautical engineer bought me pondering in regards to the legendary creatures and it struck me that to be able to fly, their world should work a bit otherwise in comparison with Earth.
It’s attainable to estimate the dimensions of a dragon by comparability to Daenerys who seems to be to be about 1.6m (5ft 3in) tall with a mass of round 60kg (132lb). The dragon’s physique appears to be about 4 occasions so long as her, round 5 occasions as deep, and about twice as large, with a tail about the identical size once more and about as thick as her physique. Assuming the density of dragon and girl are about the identical then a totally grown dragon’s mass should be round 44 occasions that of Daenerys: round 2,600kg (5,700lb).
Contemplating everybody in Westeros appears to maneuver in the same approach to us on Earth, let’s assume the identical gravitational pull, which places the dragon’s weight at 26,000 Newtons (which we’ll name W) at a nominal acceleration attributable to gravity of ten metres per second per second (32 ft/s/s).
If we’re to grasp the aerodynamics of flying dragons, we’d like two extra bits of knowledge. First, the wing space. Every wing appears to have a span roughly twice the dragon’s most important physique size, so let’s approximate the wings as two rectangles 4m by 8m (13 by 26ft), or 64m2 (340ft), which we’ll name S.
Second, the stalling pace, or slowest that the dragon can safely fly earlier than it falls out of the sky. It could be affordable to guess that dragons take off and land at roughly their stalling pace, simply as aeroplanes and birds do. Judging by the programmes evidently the dragon’s body-length of about 13m passes by in about three seconds, which places the stalling pace at about 4.3 m/s or 14 ft/s.
Dragon aerodynamics
As an engineer, when introduced with any downside I normally to resort to arithmetic, on this case the customary raise equation of:
which I can re-arrange to:-
If we use the usual earth sea-level air density of ρ = 1.2kg/m3, this provides a raise coefficient of 36. Which is totally unrealistic.
By comparability, a Rogallo winged microlight aeroplane – a tiny single or two-seater aeroplane comprising a lightweight body and a small engine suspended under a grasp gliding-style textile wing – would have a raise coefficient of between 2.2 and a pair of.7. Little doubt evolution has tailored the dragon’s wing to be extremely environment friendly, however I needed to make some assumptions right here, so went for a most raise coefficient (or CL.max) of three.5.
Disregarding the potential for magic, this tells us that the ambiance of Westeros should be way more dense than ours. Utilizing the identical figures, we are able to work out simply how dense:
12 kg/m3, or about 10 timesthat Earth regular (we name that 10 bar) sounds unpleasantly excessive, however truly isn’t that dangerous. It’s about what a diver would expertise at 100 metres depth – completely survivable.
There’s empirical proof that helps this. Watching a couple of episodes of Sport of Thrones you’ll discover that just about anyone can choose up a spear or sword and throw it distances that an Olympic javelin thrower could be deeply envious of. On condition that gravity appears to be roughly just like ours, this implies the thrown weapons are producing far more raise than on Earth – in line with an environment of upper density.
There’s one thing within the air
What’s the mixture of gases on this ambiance, I questioned? Earth’s ambiance is 21% oxygen, 78% nitrogen, and 1% numerous different gases. We all know that 21% oxygen is ok – you and I are respiration it for the time being – whereas 30% oxygen concentrations causes nearly every little thing to turn out to be extremely flammable (past that begins to verge on explosive). This appears fairly seemingly on Westeros, as anyone going close to the slightest puff of dragon breath appears to catch fireplace, whereas it’s noticeable that many of the locals are all paranoid about lighting fires anyplace besides inside a stone fortress. Westeros in all probability has a high-density air with round 30% oxygen, however no extra.
What of the remainder? I’m going to hazard an informed guess right here that it might not be nitrogen that we’re used to on Earth, however is as a substitute argon – an inert gasoline which is the following most typical gasoline on earth after nitrogen. Argon is 42% extra dense than nitrogen and would permit a higher-density ambiance at a strain a bit decrease than 10 bar.
There are two legal guidelines referring to gases that can be utilized right here to work out the behaviour of the air mixture of argon and oxygen: Charles’ Legislation so as to add the elements up, and Boyle’s Legislation to indicate what occurs when the strain will increase. Making use of these I can present that at about seven ambiance’s strain, a 70% argon, 30% oxygen ambiance has our air density of 12kg/m3, and so dragons can fly. In easy phrases – we are able to have a extra dense ambiance if the air is heavier – on this case by changing the inert nitrogen now we have on earth with the heavier (or extra precisely, denser) argon.
This argon-oxygen (or argox) combine will truly be reasonably narcotic when breathed at excessive pressures. Maybe this may partly clarify the often irrational and downright aggressive behaviour seen amongst many voters of Westeros.
So a little bit of fundamental physics, aerodynamics, and a few working information of human physiology can inform you a large number about Westeros – the place dragons fly, fireplace is to be feared, and the individuals’s irrational behaviour shouldn’t be essentially all the way down to what they’re consuming, however what they’re respiration.
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