The next essay is reprinted with permission from The Conversation, an internet publication overlaying the most recent analysis.
Like many individuals, I’ve not too long ago turn into fascinated the lives and loves of the ruling courses of the individuals of Westeros, the place the often charming inhabitants spend numerous time bickering about who’s in cost. Game of Thrones may 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 infrequently using dragons. My background as an aeronautical engineer acquired me considering about the mythical creatures and it struck me that to be able to fly, their world should work a bit in a different way in comparison with Earth.
It’s potential to estimate the dimensions of a dragon by comparability to Daenerys who appears to be about 1.6m (5ft 3in) tall with a mass of round 60kg (132lb). The dragon’s physique appears to be about 4 instances so long as her, round 5 instances as deep, and about twice as extensive, 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 completely grown dragon’s mass should be round 44 instances that of Daenerys: round 2,600kg (5,700lb).
Contemplating everybody in Westeros appears to maneuver in an analogous 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 due to gravity of ten metres per second per second (32 ft/s/s).
If we’re to know the aerodynamics of flying dragons, we want two extra bits of data. 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 speed, or slowest that the dragon can safely fly earlier than it falls out of the sky. It might be cheap to guess that dragons take off and land at roughly their stalling velocity, simply as aeroplanes and birds do. Judging by the programmes it appears that evidently the dragon’s body-length of about 13m passes by in about three seconds, which places the stalling velocity 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 mathematics, on this case the standard lift equation of:
which I can re-arrange to:-
If we use the usual earth sea-level air density of ρ = 1.2kg/m3, this offers a lift coefficient of 36. Which is totally unrealistic.
By comparability, a Rogallo winged microlight aeroplane – a tiny single or two-seater aeroplane comprising a light-weight body and a small engine suspended beneath a cling gliding-style textile wing – would have a carry coefficient of between 2.2 and a pair of.7. Little question 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 carry coefficient (or CL.max) of three.5.
Disregarding the opportunity of magic, this tells us that the environment of Westeros should be way more dense than ours. Utilizing the identical figures, we will work out simply how dense:
12 kg/m3, or about 10 timesthat Earth regular (we name that 10 bar) sounds unpleasantly excessive, however really 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 just a few episodes of Recreation of Thrones you’ll discover that just about anyone can decide up a spear or sword and throw it distances that an Olympic javelin thrower can be deeply envious of. Provided that gravity appears to be roughly just like ours, this implies the thrown weapons are producing rather more carry than on Earth – according to an environment of upper density.
There’s one thing within the air
What’s the mixture of gases on this environment, I puzzled? Earth’s environment is 21% oxygen, 78% nitrogen, and 1% varied different gases. We all know that 21% oxygen is ok – you and I are respiration it in the intervening time – whereas 30% oxygen concentrations causes nearly every part to become highly flammable (past that begins to verge on explosive). This appears fairly possible on Westeros, as anyone going close to the slightest puff of dragon breath appears to catch hearth, whereas it’s noticeable that many of the locals are all paranoid about lighting fires anyplace besides inside a stone citadel. 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 an alternative 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 environment 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’ Law so as to add the parts up, and Boyle’s Law to indicate what occurs when the strain will increase. Making use of these I can present that at about seven environment’s strain, a 70% argon, 30% oxygen environment has our air density of 12kg/m3, and so dragons can fly. In easy phrases – we will have a extra dense environment 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 really be moderately narcotic when breathed at excessive pressures. Maybe this may partially clarify the often irrational and downright aggressive behaviour seen amongst many voters of Westeros.
So a little bit of primary physics, aerodynamics, and a few working data of human physiology can inform you a large number about Westeros – the place dragons fly, hearth is to be feared, and the individuals’s irrational behaviour will not be essentially right down to what they’re consuming, however what they’re respiration.
This text was initially revealed on The Conversation. Learn the original article.