- For other uses of the term ether (and aether), see the fork page ether
'Ether’, or æther, was
the stuff used to replenish mana/MP Ike’s signature skill in Fire Emblem an invisible substance that was theorized to fill all the problem parts in early (pre-Einstein) physics theories.
In its final incarnation, it was invoked to fill all of outer space, thus explaining how light could travel its expanses with no medium to carry it.
 A brief history of ether
|This section requires expansion.|
Ether had a long and respected history in physics. It generally played the role of That Thing Which Magically Solves All the Problems in My Pet Theory, a role currently enjoyed by dark energy.
The idea of an ether-like substance in physics has been around since Aristotle, whose essay in Physics Book IV, section 8 was eventually summarized over the years as the statement: „Nature abhors a vacuum”. This concept led philosophers to speculate that all the empty space in the world must’' be filled with something, even when they didn’t appear to be. That thing was, of course, ether.
Since mechanical waves need a medium, it was concluded that light and radio waves must need a medium, the ether, as well. Originally aether was believed to be a fluid, i.e. a gas or a liquid. When in the early 19th century Malus discovered polarisation, proponents of the wave theory of light, i.e. Young and Fresnel, were forced to assume that it is a transverse wave. Such waves can propagate only in solids.
The idea was upheld in the late nineteenth century when the Michelson-Morley experiment
disproved its existence put it in a big trouble. The idea of aether had its apologists as late as in the 1920s, when the most advanced Lorentz aether theory was finally disproved. Some defenders of the aether, i.e. Dayton C. Miller and Herbert E. Ives, conducted their experiments and held to their beliefs as late as in 1930s.