Why Do Rocks Float

Exactly what the title says. The Floating City of Nym, the Churning Mists, the Sea of Clouds. All massive landmasses -- the latter two more so than the first, of course -- that float, and no adequate explanation I can find about precisely why and how they're floating. Even the rocks around the first part of T6 are floating.

Maybe the Rule of Cool is supposed to be in play here, but I refuse to suspend my disbelief for this. The only floating continent that is even vaguely explained for me is Azys Lla, and that's just some technobabble with Allagan tech.

So far, the only clue I've found as to why these things are floating is the crystals they're on. What do these crystals do, and is that why they're floating?

I believe it is disturbances with aether caused by the Calamity which sent wind sprites wild and, in places with a particularly high concentration of them, they'd begin to cause landmasses to float.

More or less, all technobabble explanations are going to be reductive back towards the simple phrase Wind Crystals Gone Wild.

Wait, so if it was the Calamity that caused these things to start floating specifically, why do the moogles in the Mists act like they've been up there for a really long time? And it's called the Floating City of Nym, so it wasn't floating before the Calamity?

Obviously it's because certain rocks in Eorzea are less dense than air.

The Floating City of Nym is believed to float due to overaspected corrupted wind crystals forming and tearing the city from the ground sometime during the fall of Nym at the end of the Fifth Umbral Era -- this theory is described in the Sightseeing Log. It's not clear whether this was intentional or accidental. We know less about the Churning Mists and Sea of Clouds, which are vastly older (prob 3rd Era or earlier). This may have been a natural formation: the two zones are prone to overaspecting of wind/lightning aether. Interview touching on subject here.

Alys La flies due to Allagan trickery.

The mechanic shows up in the single-person airship and the Fishing Log's skyfishing. Wind-aspected aether not only has an association with the movement of air, but with raising materials from the ground.

The sea of clouds has an abundance of green crystals in the lower parts of the rocks, definitely wind crystals and possibly of the corrupted variety though I'm not sure of the visual difference if any. As for WHY they are there: If i remember the Vanu myth regarding Bismarck correctly it mentions the gods raising the sea of clouds into the heavens when they resurrected Bismarck. So I'm going to blame the Allagans.

All the floating landmasses are cuased by Rocks with high concentrations of Aetherically charged Wind crystals. This actually has an effect on what can grow on them to since its commented in the Botany quests that many plants struggle in soil with so little Aetheric earth and such large concentrations of Aetheric Air.

The reasons for it happening are probably rather varied. In some cases it likely caused by disasters, in some cases its almost certainly artificially caused, and in some cases it seems likely to have happened naturally. Nym for example was caused by a disaster of overaspected wind crystal. My personal theory was this was a desperate attempt by the Scholars of Nym to save the city from the flood of the 6th Calamity in the same way the Mhachi used the Void Ark to escape the flood. We know that there is a scholar credited as saving Nym but we aren't told how.

The Isles in the Sea of Clouds seem to be more likely to be natural. The Moggles at least have been living up in the sky for quite a long time. Their legend of King Moogle Mog mentions that some Moogles were sent to find a home in the lands below after 'Fire rained from the Skys' and destroyed the landmass they lived on breaking it up into pieces. Wether this is just refering to the Churning Mists and the Fires were a reference to the start of the Dragonsong War or an older story refering to an earlier calamity isn't clear but there were Moggles living in the Sea of Clouds at one point.

hmm... must find these corrupted wind crystals so i can grind them into powder to fly like peter pan :D

I can help but wonder if the reason why there are aesthetically charged wind crystals that allows for some landmasses to float was due to the 1st Umbral Era, which was wind-aspected. That the over abundance of wind-aether infused with the earth and made some of them float, thus creating the 1st Floating Continents?