Æther
The Concept of Luminiferous Æther was irrefutably proven by the Michelson & Morley experiment of 1887. Æther physics then started to plumb the depth of ætherial mechanics. The æther is a medium of immense elasticity and extreme tenuity, which pervades all normal space, the interior of solid bodies not excepted, it is the medium of transmission of light and gravity; hence is sometimes referred to as luminiferous or light conducting.
The term "Æther" is generally applied to space and space faring equipment and methods, such as, Ætherdrive, Æthervox, Æther Marine, Æther Whale, etc.