Quote Originally Posted by Lurina View Post
"extremely powerful interstellar civilization somehow fails to discover that dark matter exists".
Dark energy. Different from dark matter.

It's called "dark" because nobody knows what it actually is, and it doesn't appear to interact with the rest of the observable universe in any way consistent with known physical laws. Dark energy in particular does not seem to have a source or point of origin: it's just presumably there, causing the expansion of the universe, and apparently evenly and consistently suffused throughout the entire universe.

Which matches the concepts of both the Sanskrit "akasha", and the classical idea of "aether". Since "aether" is already used in FFXIV's setting to mean something specific, I can understand the writing team using "akasha" to refer to the non-aether dynamis.