The Layman's Physics Discussion

[Sylvain]

However, hydealyn being a magical world, the unknown properties of ether must always be taken into consideration as it seems to be an integral part of the world to its very core. In short, we can\\\\\\\\\\'t explain ff14 physic without understanding ether, and unfortunately no one does. (and I doubt SE has hired any physicist to make some pseudo science out of thin air to make a magical world more believable)

So, as Y. P would say, "it\\\\\\\\\\'s Magic"

[YianKutku]

I forgot where I first heard it or the exact wording, but I recall a saying about SF&F storytelling about how the softer the science, the harder it is to get away with suspension of disbelief. Hence the myriad threads we have about morality and philosophy of in-game characters.

I suspect there is also a corollary to the saying, which is the harder the science, the softer we are on suspension of disbelief. So the vast majority of weird stuff in the game setting is handwaved away with "magic", or specifically "aether". For example, the critters that can fly without wings are said to do so by directly manipulating the wind aether around them. How exactly this works can probably be vaguely dismissed until someone else works it out (by forcing interpretations and coming up with explanations on the fly), at which point the lore pretty much goes "eh, good enough".

Having said that, I could have sworn there's a sidequest or Job quest with a NPC from one of the three starter city-states who has to go up Sohm Al to the Churning Mists, and complains of shortness of breath due to the high altitude. I can't remember where it is, though, or if I imagined the entire thing.

We even have canonical examples of people from Othard coming to Eorzea and getting aether sickness from the sheer amount of aether around, so there's precedent for acclimatization issues.